Solid Power, Inc. 10-K

Item 8. Financial Statements and Supplementary Data Report of Independent Registered Public Accounting Firm ( Deloitte & Touche LLP ; Denver, CO ; PCAOB ID: 34 ) 44 Report of Independent Registered Public Accounting Firm ( Ernst & Young LLP ; Denver, CO ; PCAOB ID: 42 ) 46 Consolidated Balance Sheets 47 Consolidated Statements of Operations and Comprehensive Loss 48 Consolidated Statements of Stockholders’ Equity 49 Consolidated Statements of Cash Flows 50 Notes to Consolidated Financial Statements 51 ​ ​ ​ Solid Power, Inc. | 2025 Form 10-K | 43 Table of Contents REPORT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM To the shareholders and the Board of Directors of Solid Power, Inc Opinion on the Financial Statements We have audited the accompanying consolidated balance sheet of Solid Power, Inc and subsidiaries (the "Company") as of December 31, 2025, the related consolidated statements of operations and comprehensive loss, stockholders' equity, and cash flows, for the year ended December 31, 2025 and the related notes (collectively referred to as the "financial statements"). In our opinion, the financial statements present fairly, in all material respects, the financial position of the Company as of December 31, 2025 and the results of its operations and its cash flows for the year ended December 31, 2025, in conformity with accounting principles generally accepted in the United States of America (GAAP). Basis for Opinion These financial statements are the responsibility of the Company's management. Our responsibility is to express an opinion on the Company's financial statements based on our audit. We are a public accounting firm registered with the Public Company Accounting Oversight Board (United States) (PCAOB) and are required to be independent with respect to the Company in accordance with the U.S. federal securities laws and the applicable rules and regulations of the Securities and Exchange Commission and the PCAOB. We conducted our audit in accordance with the standards of the PCAOB​. Those standards require that we plan and perform the audit to obtain reasonable assurance about whether the financial statements are free of material misstatement, whether due to error or fraud. The Company is not required to have, nor were we engaged to perform, an audit of its internal control over financial reporting. As part of our audit, we are required to obtain an understanding of internal control over financial reporting but not for the purpose of expressing an opinion on the effectiveness of the Company's internal control over financial reporting. Accordingly, we express no such opinion. ​ Our audit included performing procedures to assess the risks of material misstatement of the financial statements, whether due to error or fraud, and performing procedures that respond to those risks. Such procedures included examining, on a test basis, evidence regarding the amounts and disclosures in the financial statements. Our audit also included evaluating the accounting principles used and significant estimates made by management, as well as evaluating the overall presentation of the financial statements. We believe that our audit provides a reasonable basis for our opinion. Critical Audit Matter The critical audit matter communicated below is a matter arising from the current-period audit of the financial statements that was communicated or required to be communicated to the audit committee and that (1) relates to accounts or disclosures that are material to the financial statements and (2) involved our especially challenging, subjective, or complex judgments. The communication of critical audit matters does not alter in any way our opinion on the financial statements, taken as a whole, and we are not, by communicating the critical audit matter below, providing a separate opinion on the critical audit matter or on the accounts or disclosures to which it relates. Revenue Recognition - Identification and evaluation of relevant terms and conditions in collaborative arrangements and application to such contracts of Accounting Standards Codification (ASC) Topic 606 – Revenue From Contracts With Customers (ASC 606) to determine overtime revenue to be recognized - Refer to Note 2 to the financial statements Critical Audit Matter Description The Company recognizes revenue from collaborative arrangements by applying the guidance within ASC 606. Revenue is recognized over time using a cost-to-cost method as performance obligations are fulfilled. The Company evaluates whether it will be subject to variable consideration under the terms of a contract and includes its estimate of variable consideration, subject to constraint, in the transaction price based on the most likely amount method when it is deemed probable of being realized based on historical experience and trends. The Company updates its estimate of the transaction price each reporting period, and the effect of variable consideration on the transaction price is recognized as an adjustment to revenue on a cumulative catch-up basis. This application of ASC 606 to these arrangements involves complexity arising from the technical accounting involved in evaluating each agreement's terms and conditions and significant estimates regarding total project costs, completion costs, and transaction price. We identified revenue recognition and the application of ASC 606 under the SK On agreements as a critical audit matter due to the Solid Power, Inc. | 2025 Form 10-K | 44 Table of Contents challenging, subjective, and complex judgment required by management to develop these estimates. Auditing management’s estimates concerning revenue under these arrangements required significant auditor judgment and extensive effort to evaluate the reasonableness of management’s estimates. How the Critical Audit Matter Was Addressed in the Audit Our audit procedures related to revenue recognized under SK On agreements included the following, among others: ● Inspected and evaluated terms and conditions in relevant contracts and supporting documents. ● Evaluated the Company’s identification of performance obligations and revenue recognition model in accordance with ASC 606. ● Evaluated the reasonableness of the methodology used by management to estimate total costs for each contract. ● Tested the costs incurred to date for the performance obligation. ● Assessed management’s intent and ability to carry out actions to achieve various milestones, including management’s estimate of variable consideration subject to constraint. ● Verified the mathematical accuracy of the revenue recognition model by validating the underlying formulas. /s/ Deloitte & Touche LLP Denver, CO February 24, 2026 We have served as the Company's auditor since 2025. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Solid Power, Inc. | 2025 Form 10-K | 45 Table of Contents Report of Independent Registered Public Accounting Firm ​ ​ To the Stockholders and the Board of Directors of Solid Power, Inc. ​ ​ Opinion on the Financial Statements ​ We have audited the accompanying consolidated balance sheet of Solid Power, Inc. (the Company) as of December 31, 2024, the related consolidated statements of operations and comprehensive loss, stockholders' equity and cash flows for the year ended December 31, 2024, and the related notes (collectively referred to as the “consolidated financial statements”). In our opinion, the consolidated financial statements present fairly, in all material respects, the financial position of the Company at December 31, 2024, and the results of its operations and its cash flows for the year ended December 31, 2024, in conformity with U.S. generally accepted accounting principles. ​ Basis for Opinion ​ These financial statements are the responsibility of the Company's management. Our responsibility is to express an opinion on the Company’s financial statements based on our audit. We are a public accounting firm registered with the Public Company Accounting Oversight Board (United States) (PCAOB) and are required to be independent with respect to the Company in accordance with the U.S. federal securities laws and the applicable rules and regulations of the Securities and Exchange Commission and the PCAOB. ​ We conducted our audit in accordance with the standards of the PCAOB. Those standards require that we plan and perform the audit to obtain reasonable assurance about whether the financial statements are free of material misstatement, whether due to error or fraud. The Company is not required to have, nor were we engaged to perform, an audit of its internal control over financial reporting. As part of our audit we are required to obtain an understanding of internal control over financial reporting but not for the purpose of expressing an opinion on the effectiveness of the Company's internal control over financial reporting. Accordingly, we express no such opinion. ​ Our audit included performing procedures to assess the risks of material misstatement of the financial statements, whether due to error or fraud, and performing procedures that respond to those risks. Such procedures included examining, on a test basis, evidence regarding the amounts and disclosures in the financial statements. Our audit also included evaluating the accounting principles used and significant estimates made by management, as well as evaluating the overall presentation of the financial statements. We believe that our audit provides a reasonable basis for our opinion. ​ ​ /s/ Ernst & Young LLP ​ We served as the Company’s auditor from 2021 to 2025. Denver, Colorado February 28, 2025 ​ ​ Solid Power, Inc. | 2025 Form 10-K | 46 Table of Contents ​ Solid Power, Inc. Consolidated Balance Sheets (in thousands, except par value and number of shares) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ ​ 2025 ​ ​ ​ 2024 Assets ​ ​ ​ ​ ​ ​ Current Assets ​ ​ ​ ​ ​ Cash and cash equivalents ​ $ 21,607 ​ $ 25,413 Marketable securities ​ ​ 229,177 ​ ​ 92,784 Accounts receivable ​ 2,155 ​ 1,393 Contract assets ​ ​ 7,490 ​ ​ — Prepaid expenses and other current assets ​ 6,998 ​ 5,646 Total current assets ​ 267,427 ​ 125,236 Long-Term Assets ​ ​ ​ ​ ​ ​ Property, plant and equipment, net ​ 86,318 ​ 97,208 Right-of-use operating lease assets, net ​ ​ 6,727 ​ ​ 7,490 Investments ​ ​ 86,997 ​ ​ 210,400 Intangible assets, net ​ 2,166 ​ 2,072 Other assets ​ ​ 1,059 ​ ​ 1,577 Loan receivable from equity method investee ​ ​ 4,398 ​ ​ 4,267 Total long-term assets ​ ​ 187,665 ​ ​ 323,014 Total assets ​ $ 455,092 ​ $ 448,250 Liabilities, Mezzanine Equity and Stockholders’ Equity ​ ​ ​ ​ Current Liabilities ​ ​ ​ ​ Accounts payable and other accrued liabilities ​ $ 8,521 ​ $ 8,409 Deferred revenue ​ 198 ​ ​ 3,150 Deferred revenue from related parties ​ ​ 172 ​ ​ — Accrued compensation ​ 7,043 ​ 7,578 Operating lease liabilities ​ ​ 861 ​ ​ 833 Total current liabilities ​ 16,795 ​ 19,970 Long-Term Liabilities ​ ​ ​ ​ ​ ​ Warrant liabilities ​ ​ 13,881 ​ ​ 8,735 Operating lease liabilities ​ ​ 7,129 ​ ​ 8,023 Other liabilities ​ ​ 1,113 ​ ​ 1,208 Total long-term liabilities ​ ​ 22,123 ​ ​ 17,966 Total liabilities ​ ​ 38,918 ​ ​ 37,936 Mezzanine Equity ​ ​ ​ ​ ​ ​ Mezzanine equity ​ ​ 470 ​ ​ 34 Stockholders’ Equity ​ ​ ​ ​ Common stock, $ 0.0001 par value; 2,000,000,000 shares authorized; 201,181,175 and 180,364,028 shares issued and outstanding as of December 31, 2025 and December 31, 2024, respectively ​ 20 ​ 18 Additional paid-in capital ​ 690,234 ​ ​ 591,394 Accumulated deficit ​ ( 274,904 ) ​ ( 181,171 ) Accumulated other comprehensive income (loss) (AOCI) ​ ​ 354 ​ ​ 39 Total stockholders’ equity ​ 415,704 ​ 410,280 Total liabilities, mezzanine equity and stockholders’ equity ​ $ 455,092 ​ $ 448,250 ​ See accompanying Notes to Consolidated Financial Statements. ​ Solid Power, Inc. | 2025 Form 10-K | 47 Table of Contents Solid Power, Inc. Consolidated Statements of Operations and Comprehensive Loss (in thousands, except number of shares and per share amounts) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the Years Ended December 31, ​ ​ ​ 2025 ​ ​ ​ 2024 ​ ​ ​ Revenue ​ ​ ​ ​ ​ ​ ​ Revenue ​ $ 17,913 ​ $ 20,139 ​ Grant income ​ ​ 3,834 ​ ​ — ​ Total revenue and grant income ​ ​ 21,747 ​ ​ 20,139 ​ Operating Expenses ​ ​ ​ ​ ​ ​ Direct costs ​ ​ 20,649 ​ ​ 20,284 ​ Research and development ​ ​ 72,513 ​ 73,341 ​ Selling, general and administrative ​ ​ 29,417 ​ 31,847 ​ Total operating expenses ​ ​ 122,579 ​ 125,472 ​ Operating Loss ​ ​ ( 100,832 ) ​ ( 105,333 ) ​ Nonoperating Income and Expense ​ ​ ​ ​ ​ ​ Interest income ​ ​ 13,204 ​ ​ 17,671 ​ Change in fair value of warrant liabilities ​ ​ ( 5,146 ) ​ ​ ( 4,508 ) ​ Interest expense ​ ​ ( 25 ) ​ ( 46 ) ​ Other expense ​ ​ ( 684 ) ​ ​ ( 2,977 ) ​ Total nonoperating income and expense ​ ​ 7,349 ​ 10,140 ​ Loss before income tax expense (benefit) ​ ​ ( 93,483 ) ​ ( 95,193 ) ​ Income tax expense (benefit) ​ ​ ( 8 ) ​ 1,194 ​ Share of net loss (income) of equity method investee ​ ​ ( 65 ) ​ ​ 133 ​ Net Loss Attributable to Common Stockholders ​ $ ( 93,410 ) ​ $ ( 96,520 ) ​ Other Comprehensive Income ​ ​ 315 ​ ​ 598 ​ Comprehensive Loss Attributable to Common Stockholders ​ $ ( 93,095 ) ​ $ ( 95,922 ) ​ Basic and diluted loss per share ​ $ ( 0.51 ) ​ $ ( 0.54 ) ​ Weighted average shares outstanding – basic and diluted ​ ​ 184,902,712 ​ 179,397,332 ​ ​ ​ ​ ​ ​ ​ ​ ​ See accompanying Notes to Consolidated Financial Statements. ​ ​ Solid Power, Inc. | 2025 Form 10-K | 48 Table of Contents Solid Power, Inc. Consolidated Statements of Stockholders’ Equity (in thousands, except number of shares) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Common Stock ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Additional ​ Accumulated ​ Accumulated ​ Total Stockholders’ ​ ​ ​ ​ Shares ​ ​ ​ Amount ​ ​ ​ paid-in capital ​ ​ ​ deficit ​ ​ ​ OCI ​ ​ ​ Equity Balance as of December 31, 2023 ​ ​ 179,010,884 ​ $ 18 ​ $ 588,515 ​ $ ( 84,639 ) ​ $ ( 559 ) ​ $ 503,335 Net loss ​ ​ — ​ ​ — ​ ​ — ​ ​ ( 96,520 ) ​ ​ — ​ ​ ( 96,520 ) Withholding of employee taxes related to stock-based compensation ​ ​ — ​ ​ — ​ ​ ( 615 ) ​ ​ — ​ ​ — ​ ​ ( 615 ) Shares of common stock issued under the ESPP ​ ​ 387,664 ​ ​ — ​ ​ 412 ​ ​ — ​ ​ — ​ ​ 412 Shares of common stock issued for vested RSUs ​ ​ 1,229,645 ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — Shares of common stock issued to Dahae executives ​ ​ 298,508 ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — Stock options exercised ​ ​ 5,141,728 ​ ​ 1 ​ ​ 272 ​ ​ — ​ ​ — ​ ​ 273 Repurchase and retirement of shares of common stock ​ ​ ( 5,704,401 ) ​ ​ ( 1 ) ​ ​ ( 9,162 ) ​ ​ — ​ ​ — ​ ​ ( 9,163 ) Remeasurement of mezzanine equity ​ ​ — ​ ​ — ​ ​ — ​ ​ ( 12 ) ​ ​ — ​ ​ ( 12 ) Unrealized gain on available-for-sale securities ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ 598 ​ ​ 598 Stock-based compensation expense ​ ​ — ​ ​ — ​ ​ 11,972 ​ ​ — ​ ​ — ​ ​ 11,972 Balance as of December 31, 2024 ​ ​ 180,364,028 ​ $ 18 ​ $ 591,394 ​ $ ( 181,171 ) ​ $ 39 ​ $ 410,280 Net loss ​ ​ — ​ ​ — ​ ​ — ​ ​ ( 93,410 ) ​ ​ — ​ ​ ( 93,410 ) Withholding of employee taxes related to stock-based compensation ​ ​ — ​ ​ — ​ ​ ( 1,032 ) ​ ​ — ​ ​ — ​ ​ ( 1,032 ) Shares of common stock issued under the ESPP ​ ​ 358,047 ​ ​ — ​ ​ 365 ​ ​ — ​ ​ — ​ ​ 365 Shares of common stock issued for vested RSUs ​ ​ 2,458,249 ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — Stock options exercised ​ ​ 3,339,162 ​ ​ — ​ ​ 5,259 ​ ​ — ​ ​ — ​ ​ 5,259 Repurchase and retirement of shares of common stock ​ ​ ( 3,361,396 ) ​ ​ — ​ ​ ( 3,502 ) ​ ​ — ​ ​ — ​ ​ ( 3,502 ) Remeasurement of mezzanine equity ​ ​ — ​ ​ — ​ ​ — ​ ​ ( 323 ) ​ ​ — ​ ​ ( 323 ) Unrealized gain on available-for-sale securities ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ 315 ​ ​ 315 Proceeds from the ATM, net of offering costs, commissions, and fees of $ 2,453 ​ ​ 18,023,085 ​ ​ 2 ​ ​ 88,760 ​ ​ — ​ ​ — ​ ​ 88,762 Stock-based compensation expense ​ ​ — ​ ​ — ​ ​ 8,990 ​ ​ — ​ ​ — ​ ​ 8,990 Balance as of December 31, 2025 ​ ​ 201,181,175 ​ $ 20 ​ $ 690,234 ​ $ ( 274,904 ) ​ $ 354 ​ $ 415,704 ​ See accompanying Notes to Consolidated Financial Statements. ​ ​ Solid Power, Inc. | 2025 Form 10-K | 49 Table of Contents Solid Power, Inc. Consolidated Statements of Cash Flows (in thousands, except par value, share amounts, and per share amounts) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the Years Ended December 31, ​ ​ ​ 2025 ​ ​ ​ 2024 ​ ​ ​ Cash Flows from Operating Activities ​ ​ ​ ​ ​ ​ ​ Net loss ​ $ ( 93,410 ) ​ $ ( 96,520 ) ​ Adjustments to reconcile net loss to net cash and cash equivalents used in operating activities: ​ ​ ​ ​ ​ ​ Depreciation and amortization ​ ​ 18,422 ​ 16,464 ​ Amortization of right-of-use assets ​ ​ 1,370 ​ ​ 900 ​ Loss on sales of property, plant, and equipment ​ ​ 574 ​ 1,957 ​ Gain on sales of property, plant, and equipment ​ ​ ( 20 ) ​ ​ — ​ Loss on extinguishment of note receivable ​ ​ — ​ ​ 760 ​ Share of net loss (income) of equity method investee ​ ​ ( 65 ) ​ ​ 133 ​ Stock-based compensation expense ​ ​ 8,990 ​ 11,972 ​ Change in fair value of warrant liabilities ​ ​ 5,146 ​ ​ 4,508 ​ Accretion of discounts on other long-term liabilities ​ ​ 65 ​ ​ 78 ​ Accretion of loan receivable from equity method investee ​ ​ ( 131 ) ​ ​ ( 24 ) ​ Amortization of premiums and accretion of discounts on available-for-sale-securities ​ ​ ( 4,691 ) ​ ​ ( 7,805 ) ​ Loss on change in assessment of finance lease purchase options ​ ​ 84 ​ ​ — ​ Impairment loss on abandoned patents ​ ​ 748 ​ ​ — ​ Change in operating assets and liabilities that provided (used) cash and cash equivalents: ​ ​ ​ ​ ​ ​ Accounts receivable ​ ​ 278 ​ ​ 160 ​ Contract assets ​ ​ ( 7,490 ) ​ — ​ Prepaid expenses and other current assets and other assets ​ ​ ( 366 ) ​ 710 ​ Accounts payable and other accrued liabilities ​ ​ 1,416 ​ 1,268 ​ Deferred revenue ​ ​ ( 2,952 ) ​ 3,150 ​ Deferred revenue from related parties ​ ​ 172 ​ ​ ( 828 ) ​ Accrued compensation ​ ​ ( 537 ) ​ ( 11 ) ​ Operating lease liabilities ​ ​ ( 996 ) ​ ​ ( 771 ) ​ Net cash and cash equivalents used in operating activities ​ ​ ( 73,393 ) ​ ( 63,899 ) ​ Cash Flows from Investing Activities ​ ​ ​ ​ ​ ​ Purchases of property, plant and equipment ​ ​ ( 10,209 ) ​ ( 15,942 ) ​ Purchases of available-for-sale securities ​ ​ ( 277,726 ) ​ ( 216,193 ) ​ Proceeds from sales of available-for-sale securities ​ ​ 268,891 ​ ​ 302,966 ​ Proceeds from sales of property, plant and equipment ​ ​ 20 ​ ​ 77 ​ Cash paid for loan receivable from equity method investee ​ ​ — ​ ​ ( 5,610 ) ​ Cash paid for equity method investment ​ ​ — ​ ​ ( 656 ) ​ Purchases of intangible assets ​ ​ ( 873 ) ​ ( 438 ) ​ Net cash and cash equivalents provided by (used in) investing activities ​ ​ ( 19,897 ) ​ 64,204 ​ Cash Flows from Financing Activities ​ ​ ​ ​ ​ ​ Proceeds from exercise of stock options ​ ​ 5,259 ​ 273 ​ Proceeds from issuance of shares of common stock under the ESPP ​ ​ 365 ​ ​ 412 ​ Cash paid for withholding of employee taxes related to stock-based compensation ​ ​ ( 1,031 ) ​ ​ ( 615 ) ​ Repurchase of shares of common stock ​ ​ ( 3,592 ) ​ ​ ( 9,072 ) ​ Proceeds from the ATM, net of commissions ​ ​ 89,391 ​ ​ — ​ Offering costs for the issuance of common stock under the ATM ​ ​ ( 624 ) ​ ​ — ​ Payments on finance lease liabilities ​ ​ ( 284 ) ​ ​ ( 427 ) ​ Net cash and cash equivalents provided by (used in) financing activities ​ ​ 89,484 ​ ​ ( 9,429 ) ​ ​ ​ ​ ​ ​ ​ ​ ​ Net decrease in cash and cash equivalents ​ ​ ( 3,806 ) ​ ​ ( 9,124 ) ​ Cash and cash equivalents at beginning of period ​ ​ 25,413 ​ ​ 34,537 ​ Cash and cash equivalents at end of period ​ $ 21,607 ​ $ 25,413 ​ ​ ​ ​ ​ ​ ​ ​ ​ Supplemental information ​ ​ ​ ​ ​ ​ ​ Cash paid for interest ​ $ 26 ​ $ 46 ​ Accrued capital expenditures ​ $ 103 ​ $ 1,196 ​ Unpaid reimbursement on capital expenditures ​ $ 1,039 ​ $ — ​ Accrued offering costs for the issuance of common stock under the ATM ​ $ 5 ​ $ — ​ ​ See accompanying Notes to Consolidated Financial Statements. ​ ​ Solid Power, Inc. | 2025 Form 10-K | 50 Table of Contents Notes to Consolidated Financial Statements (in thousands, except number of shares and per share amounts) Note 1 – Nature of Business Solid Power, Inc. (the “Company”) is developing solid-state battery technology for the battery electric vehicle (“EV”) and other markets. The Company’s planned business model is to sell its electrolyte and to license its cell designs and manufacturing processes. Note 2 – Significant Accounting Policies Basis of Presentation and Principles of Consolidation The Consolidated Financial Statements have been prepared on the basis of U.S. generally accepted accounting principles (“GAAP”) and pursuant to the rules and regulations of the Securities and Exchange Commission. The preparation of Consolidated Financial Statements in conformity with GAAP requires management to make estimates and assumptions that affect amounts reported in the Consolidated Financial Statements. Actual results could differ from those estimates. All amounts presented in the footnotes are in thousands, except share and per share amounts or as otherwise indicated. The Consolidated Financial Statements include accounts of the Company and its wholly owned subsidiaries. All intercompany balances and transactions have been eliminated in consolidation. The Company accounts for its equity ownership in Dahae Energy Co., Ltd. (“Dahae”), an entity in which the Company does not exercise control or have the obligation to absorb losses or receive benefits, as a variable interest entity (“VIE”). A VIE is a legal entity that possess any of the following conditions: the entity’s equity at risk is not sufficient to permit the legal entity to finance its activities without additional subordinated financial support, equity owners are unable to direct the activities that most significantly impact the legal entity’s economic performance (or they possess disproportionate voting rights in relation to the economic interest in the legal entity), or the equity owners lack the obligation to absorb the legal entity’s expected losses or the right to receive the legal entity’s expected residual returns. The Company consolidates a VIE if the Company determines that it has (i) the power to direct activities of the VIE that most significantly impact its economic performance and (ii) the obligation to absorb losses or the right to receive benefits from the VIE that are more than insignificant to the VIE. If an entity is determined to be a VIE but the Company does not have a controlling interest, the entity is accounted for under either the cost or equity method depending on whether the Company exercises significant influence. The Company has determined that it does not meet the control requirements to consolidate Dahae and accounts for the investment using the equity method of accounting. The Company evaluates its investment with Dahae on an ongoing basis, including when the Company believes a loss in value may have occurred which is other than temporary. The Company measures its equity method investment at cost minus impairment, if any, plus or minus the share of the equity method investee’s loss or gain. Activity is included in Investments in the Consolidated Balance Sheets and separately within Share of net loss (income) of equity method investee in the Consolidated Statements of Operations and Comprehensive Loss and within Cash Flows from Investing Activities in the Consolidated Statements of Cash Flows. Reclassification of Prior Year Presentation Certain prior period amounts have been reclassified to conform to current period presentation in the accompanying Consolidated Financial Statements. Beginning in January 2025, reclassifications have been made to prior year amounts within the Consolidated Balance Sheets related to finance leases in which balances have been moved from Right-of-use financing lease assets to Other Assets; Finance lease liabilities, short term to Accounts payable and other accrued liabilities, and Finance lease liabilities, long term to Other liabilities. These changes had no effect on reported results of operations. Beginning January 2025, reclassifications have been made to prior year amounts within the Consolidated Statements of Cash Flows in which the Company reclassified the accretion of loan receivable from equity method investee separately from being included in amortization of premiums and accretion of discounts on available-for-sale-securities. Segment Reporting The Company’s Chief Operating Decision Maker (“CODM”) is its Chief Executive Officer. The Company has determined that it operates in one operating segment and one reportable segment as the CODM reviews financial information presented as a single entity for purposes of making operating decisions, allocating resources, and evaluating financial performance. The CODM manages the business on a consolidated basis and uses consolidated Net Loss Attributable to Common Stockholders as reported in the Consolidated Statements of Operations and Comprehensive Loss as the profit or loss measure in assessing performance and deciding how to allocate resources. The CODM is regularly provided with only the consolidated expenses in the Consolidated Statements of Operations and Comprehensive Loss, which are the significant segment expenses. The CODM uses this information to assess business performance and strategy, prepare the annual operating budget and financial forecasts, and communicates with the Board of Directors Solid Power, Inc. | 2025 Form 10-K | 51 Table of Contents concerning the Company’s financial performance. The CODM does not evaluate the Company’s one reportable segment using asset information, and, accordingly, the Company does not report asset information. See Note 15 – Segment Disclosure for more information. Use of Estimates The preparation of financial statements in accordance with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets, liabilities, and contingencies at the date of the financial statements as well as reported amounts of revenues and expenses during the reporting periods. Estimates made by the Company include, but are not limited to, those related to the measurement of revenue for collaborative arrangements, valuation of warrants, valuation of stock-options and useful lives of long-term assets, among others. The Company bases these estimates on historical experience and other assumptions that it believes are reasonable under the circumstances. Cash and Cash Equivalents The Company considers all highly liquid investments with an original maturity of three months or less when purchased to be cash equivalents. As of December 31, 2025 and throughout the year, the Company’s cash accounts exceeded federally insured limits. Available-for-Sale Securities The Company’s investment policy is consistent with the definition of available-for-sale securities, and the accounting is recorded under Accounting Standards Codification (“ASC) 326-30. The Company’s investments are not classified as trading securities or as held-to-maturity securities and therefore are classified as available-for-sale securities. The Company does not buy and hold securities principally for the purpose of selling them in the near future. The Company’s policy is focused on the preservation of capital, liquidity, and return. From time to time, the Company may sell certain securities, but the objectives are not to generate profits on short-term differences in price. These securities are carried at estimated fair value with unrealized holding gains and losses included in accumulated other comprehensive income (loss) in stockholders’ equity until realized. Gains and losses on available-for-sale securities are reported on the specific-identification method. Dividend and interest income are recognized when earned. The Company classifies all available-for-sale securities with a maturity date of 12 months or less to be Marketable securities and all with a maturity greater than 12 months to be Investments within the Consolidated Balance Sheets. Account Receivables The Company distinguishes between a contract asset and an accounts receivable based on whether receipt of the consideration is conditional on something other than the passage of time. When the Company transfers control of goods or services to a customer before the customer pays consideration, the Company records a contract asset or a receivable depending on the nature of the Company’s right to consideration for its performance. The point at which a contract asset becomes an accounts receivable may be earlier than the point at which an invoice is issued. The Company assesses a contract asset and accounts receivable for impairment in accordance with ASC 326 Financial Instruments – Credit Losses. The Company has not recorded an allowance for credit losses as of December 31, 2025 and 2024. Contract assets are classified separately on the Consolidated Balance Sheets and transferred to accounts receivable when right to payment becomes unconditional. Amounts for work performed but not billed as of December 31, 2025, and 2024 are included within accounts receivables and shown in the table below. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ ​ 2025 ​ ​ ​ 2024 Accounts receivable not billed ​ ​ 2,068 ​ ​ 438 ​ Credit Risk and Major Customers Financial instruments that potentially subject the Company to credit risk consist principally of cash and cash equivalents, marketable securities, accounts receivable, contract assets, investments and loan receivables. The Company seeks to mitigate its credit risk with respect to cash and cash equivalents, marketable securities, and investments by making deposits with large, reputable financial institutions and investing in high credit rated instruments. Solid Power, Inc. | 2025 Form 10-K | 52 Table of Contents The Company grants credit in the normal course of business to government entities and commercial contractors. The Company periodically monitors the financial condition of its customers to reduce credit risk, but generally does not require collateral to support accounts receivable or contract assets. The table below sets forth revenue and account receivables and contract asset concentration for customers that accounted for more than 10% of the Company’s total gross revenue for the years ended December 31, 2025, and 2024. ​ ​ ​ ​ ​ ​ ​ ​ ​ For the Years Ended December 31, ​ ​ ​ ​ ​ 2025 ​ ​ ​ 2024 ​ ​ ​ Revenue concentration ​ ​ ​ ​ ​ Number of customers ​ 3 3 Related total revenue percentage 95 % 98 % Accounts receivable concentration ​ ​ Number of customers 2 2 Related contract receivable and contract asset percentage 98 % 94 % Contract asset concentration ​ ​ ​ ​ ​ Number of customers ​ 1 ​ — ​ Related contract receivable and contract asset percentage ​ 100 % — % ​ Property, Plant and Equipment Property, plant and equipment are recorded at cost. The Company capitalizes property, plant and equipment with useful lives exceeding one year. Assets are depreciated over their estimated useful lives. The straight-line method is used for computing depreciation. Depreciation expenses are recorded in Operating Expenses in the Consolidated Statements of Operations and Comprehensive Loss. Cost of maintenance and repairs are charged to expense when incurred. Construction in progress related to specialized equipment, once placed in service will be classified into one of the categories listed in the table below of Property, plant and equipment and depreciated. ​ ​ ​ ​ ​ ​ ​ ​ Depreciable Life Production equipment ​ 5 years Laboratory equipment ​ 5 years Furniture and computer equipment 3 - 7 years Leasehold improvements Lesser of asset life or lease term ​ Investments The Company considers all available-for-sale securities with a maturity date of less than 12 months to be marketable securities and all with a maturity date greater than 12 months to be investments. See Note 5 – Fair Value Measurement for more information. The Company records its investments in non-marketable equity securities in accordance with ASC 321 – Investments - Equity Securities. Under the measurement alternative, carrying value is measured at cost, less any impairment, plus or minus changes resulting from observable price changes in orderly transactions for identical or similar investments of the same issuer. Adjustments are determined at fair value as of the transaction date. The Company’s equity securities investment is presented in Investments in the Consolidated Balance Sheets. The Company’s non-marketable equity securities investment, as noted in Note 11 – Related Party Transactions, is evaluated for impairment based on qualitative factors, including the investee’s financial and liquidity position and access to capital resources, among others. When indicators of impairment exist, a loss is recorded equal to the difference between the fair value and carrying value of the investment. The Company acquired an equity interest in Dahae in October 2024. The Company has determined that Dahae is a VIE. The Company does not have a controlling financial interest in Dahae and, therefore, accounts for its investment using the equity method of accounting. As a result of the Company’s equity interest in Dahae, Dahae is a related party. See Note 11 – Related Party Transactions for more information. ​ Solid Power, Inc. | 2025 Form 10-K | 53 Table of Contents Loan Receivable from Equity Method Investee The Company accounts for its loan receivable from its equity method investee, Dahae at its stated principal amount, net of any discount or premium. The related discounts or premiums on the loan receivable are amortized or accreted over the term of the loan receivable. The Company classifies its loan receivable on a current (due within 12 months of reporting date) and a long-term (due in excess of 12 months from reporting date) basis in accordance with the stated maturity date. Interest income is accrued based on the contractual terms which are payable on a quarterly basis. Interest income from the loan receivable is presented as Interest income in the Consolidated Statements of Operations and Comprehensive Loss. Any interest receivable from the loan receivable represents a current asset within Prepaid expenses and other current assets in the Consolidated Balance Sheets. Accretion of discount on bond, which increases the bond to the par value of a bond, is recorded on a quarterly basis and presented as Interest income in the Consolidated Statements of Operations and Comprehensive Loss. The Company applies ASC 326 – Measurement of Credit Losses on Financial Instruments to financial assets measured at amortized cost, including the loan receivable from Dahae. The Company utilizes the discounted cash flow method to estimate current expected credit losses. The Company has not recognized an allowance for current expected credit losses on its loan receivable and does not have any loans receivable in nonaccrual status. See Note 11 – Related Party Transactions for more information. Intangible Assets Intangible assets consist of licenses and costs incurred for pending patents and trademarks. Licenses consist of rights to use patents and are amortized over their estimated useful life of three to 20 years . Patent costs are amortized over an estimated useful life upon award by the United States Patent and Trademark Office or expensed if the Company is unsuccessful in securing an issued patent. Trademarks have an indefinite life and therefore are not amortized. Intangible assets that are subject to amortization are reviewed for potential impairment whenever events or circumstances indicate that carrying amounts may not be recoverable. Assets not subject to amortization are tested at least annually or more frequently for impairment if events or circumstances indicate an impairment may have occurred. Leases The Company accounts for its leases under ASC 842 – Lease Accounting. Under this guidance, the Company classifies contracts meeting the definition of a lease as operating or financing leases, and leases are recorded in the Consolidated Balance Sheets as both a right-of-use asset and lease liability, calculated by discounting fixed lease payments over the lease term at the rate implicit in the lease or the Company’s incremental borrowing rate. Lease liabilities are increased by interest and reduced by payments each period, and the right-of-use asset is amortized over the lease term. For operating leases, interest on the lease liability and the amortization of the right-of-use asset result in straight-line rent expense over the lease term. For finance leases, interest on the lease liability and the amortization of the right-of-use asset results in front-loaded expense over the lease term. Variable lease expenses, including common maintenance fees, insurance and property tax, are recorded when incurred. In calculating the right-of-use asset and lease liability, the Company elects to combine lease and non-lease components for all classes of assets. The Company, as an accounting policy election, does not recognize right-of-use asset and lease liability on short-term leases (which are leases having initial terms of 12 months or less) and instead recognizes rent expense on a straight-line basis over the lease term. Stock-Based Compensation Stock-based compensation primarily consists of stock options, restricted stock units (“RSUs”), and restricted stock grants to Dahae executives. Expenses for stock-based compensation are measured based at fair value on the date of the grant and recognized over the prescribed vesting schedule as described within Note 8 – Stock-Based Compensation. The estimated fair value of stock options on the date of grant is calculated using the Black-Scholes option-pricing model and is affected by the Company’s stock price, as well as assumptions regarding risk-free rate, dividend yield, and the historical volatility of comparable entities. The estimated fair value of RSUs is determined based on the number of shares granted and the closing price for of the Company’s common stock as of the date of the grant. The Company accounts for forfeitures as they occur. Employee compensation cost is recognized on a straight-line basis over the requisite vesting service period and is recorded in Operating Expenses in the Consolidated Statements of Operations and Comprehensive Loss. The Company recognizes expenses for restricted stock grants to Dahae executives based on the grant date fair value of the restricted stock grants, which is based on the closing price of the Company’s common stock as of the date of the grant. Dahae Solid Power, Inc. | 2025 Form 10-K | 54 Table of Contents executive stock-based compensation expenses are recognized on a straight-line basis over the Dahae executives vesting period. Dahae executive stock-based compensation related to restricted stock grants is recognized within Share of net loss (income) of equity method investee in the Consolidated Statements of Operations and Comprehensive Loss. Revenue and Grant Income The Company assesses all collaborative arrangements to determine whether the agreement should be recorded in accordance with Accounting Standards Codification (“ASC”) 808 – Collaborative Arrangements. Collaborative arrangements involve two or more parties who are active participants and meet the following components: both parties are exposed to significant risks and rewards, and both parties are dependent on the commercial success of the efforts under the contract. Revenue recognition is recorded by analogy to ASC 606 – Revenue from Contracts with Customers. This application of ASC 606 to these arrangements involves complexity arising from the technical accounting involved in evaluating each agreement's terms and conditions and significant estimates regarding total project costs, completion costs, and transaction price. The Company’s agreements with SK On Co., Ltd. (“SK On” and such agreements, the “SK On Agreements”) meet the criteria of collaborative arrangements. Amounts received for these products and services are classified as Revenue in the Condensed Consolidated Statements of Operations and Comprehensive Loss. ​ Prior to January 1, 2025, the Company recognized revenue from the Company’s collaborative arrangement, including the SK On Agreements, over time using the input measurement method utilizing labor hours in relation to total labor hours anticipated to satisfy the performance obligation. Effective January 1, 2025, the Company changed its basis of input to utilize the cost-to-cost method to satisfy the performance obligation. The Company made the change because it believes using the cost-to-cost method provides more accurate reflection of how performance is satisfied over time. This change is treated as a change in estimate beginning on January 1, 2025, and prior period amounts have not been adjusted. The Company expenses contract fulfillment costs as incurred. As of December 31, 2025, the Company’s remaining performance obligation unsatisfied was $ 27,760 to be recognized through 2028 . ​ The Company evaluates whether certain transactions under contracts with customers are variable consideration under the terms of a contract and includes its estimate of variable consideration, subject to constraint, in the transaction price based on the most likely amount method when it is deemed probable of being realized based on historical experience and trends. The Company updates its estimate of variable considerations included in the transaction price each reporting period, and the effect of variable consideration on the transaction price is recognized as an adjustment to revenue on a cumulative catch-up basis. ​ The Company recognizes revenue from cooperative agreements with the government in cost contracts on the basis of costs incurred during the period and in cost plus fixed-fee contracts on the basis of costs incurred during the period plus the fee earned. Contract costs include all direct labor, subcontract, material, and indirect costs related to the contract performance which is included in Direct costs within the Consolidated Statement of Operations and Comprehensive Loss. ​ On January 21, 2025, Solid Power Operating, Inc., a consolidated subsidiary, entered into an assistance agreement with the U.S. Department of Energy (“DOE”) with an effective date of January 1, 2025 (as amended effective May 15, 2025, the “Assistance Agreement”). The Assistance Agreement provides that the DOE will provide the Company with funding of up to $ 50,000 for the Company’s installation of equipment necessary for the continuous production of sulfide-based electrolyte material pilot line. The Company records grant income from the Assistance Agreement in accordance with International Accounting Standards 20 when conditions have been substantially met. This income is presented within Grant income in the Consolidated Statements of Operations and Comprehensive Loss. ​ For electrolyte sales, the Company recognizes revenue when the control of the goods is transferred to the customer and for the amount of consideration the Company expects to receive. ​ The Company receives revenue and grant income from both government and non-government entities. Government revenue and grant income includes both revenue and grant income from collaborative arrangements. Non-government revenue includes both revenue from collaborative arrangements and electrolyte sales. The table below sets forth revenue and grant income by type for the year ended December 31, 2025, and 2024. ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ​ 2025 ​ ​ ​ 2024 Government - revenue $ 2,124 ​ $ 2,732 Government - grant income ​ 3,834 ​ ​ — Non-government revenue ​ 15,789 ​ ​ 17,407 Total revenue and grant income $ 21,747 ​ $ 20,139 ​ ​ Solid Power, Inc. | 2025 Form 10-K | 55 Table of Contents Deferred revenue represents cash collected in advance of revenue recognized. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ ​ 2025 ​ ​ ​ 2024 Deferred revenue ​ $ 198 ​ $ 3,150 Deferred revenue from related parties ​ ​ 172 ​ ​ — ​ Warrant Liabilities The Company accounts for warrants as liability-classified instruments based on an assessment of the warrant’s specific terms and applicable authoritative guidance in ASC 480 – Distinguishing Liabilities from Equity and ASC 815 – Hedge Accounting. Warrants recorded as liabilities are recorded at their fair value within Warrant liabilities in the Consolidated Balance Sheets and are remeasured on each reporting date with changes recorded in Change in fair value of warrant liabilities in the Company’s Consolidated Statements of Operations and Comprehensive Loss. Fair Value Measurements The Company applies fair value accounting for selected financial assets and liabilities measured on a recurring and nonrecurring basis. Fair value is defined as an exit price, representing the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. As such, fair value is a market-based measurement that should be determined based on assumptions that market participants would use in pricing an asset or a liability. The accounting guidance ASC 820 – Fair Value Measurement established a fair value hierarchy based on three levels of inputs, of which the first two are considered observable and the last unobservable, used to determine the fair value of financial instruments. A financial instrument’s level within the fair value hierarchy is based on the lowest level of any input that is significant to the fair value measurement. Level 1 – inputs include quoted market prices in an active market for identical assets or liabilities. Level 2 – inputs are market data, other than Level 1 inputs, that are observable either directly or indirectly, including quoted market prices for similar assets or liabilities, quoted market prices in an inactive market, and other observable information that can be corroborated by market data. Level 3 – inputs are unobservable and corroborated by little or no market data. Research and Development The Company’s research and development activities focus on making improvements to its electrolyte and cell technologies with the ultimate goal of commercializing technology that outperforms conventional lithium-ion. Costs related to research and development are expensed as incurred. Income Taxes The Company recognizes deferred tax liabilities and assets for the expected future tax consequences of events that have been included in the Consolidated Financial Statements or tax returns. Deferred tax liabilities and assets are determined based on the differences between the Consolidated Financial Statements and tax basis of assets and liabilities using the enacted tax rates in effect for the year in which the differences are expected to reverse. The measurement of deferred tax assets is reduced, if necessary, by the amount of any uncertain tax positions or tax benefits that are not expected to be realized based on available evidence. The Company records deferred tax assets and associated valuation allowances, when appropriate, to reflect amounts more likely than not to be realized based on the Company’s analysis. The Company’s temporary differences result primarily from capitalization of certain qualifying research and development expenses, accruals and reserves, depreciation of property, plant and equipment, stock compensation expense, capitalization of operating or financing leases, and net operating loss carryovers. The Company provides deferred U.S. federal, state, or foreign income tax benefits for periods presented. The Company has also provided a valuation allowance on the net deferred tax asset because of uncertainty regarding realizability. Realization of deferred tax assets is dependent on generating sufficient taxable income prior to the expiration of loss carryforwards. Solid Power, Inc. | 2025 Form 10-K | 56 Table of Contents The Company accounts for any uncertainty in income taxes by recognizing the tax benefit from an uncertain tax position only if it is more likely than not that the tax position will be sustained on examination by the taxing authorities, based on the technical merits of the position. The Company measures the tax benefits recognized in the Consolidated Financial Statements from such a position based on the largest benefit that has a greater than 50% likelihood of being realized upon ultimate resolution. Interest and penalties associated with tax positions are recorded in the period assessed as Selling, general and administrative in the Consolidated Statements of Operations and Comprehensive Loss. No interest or penalties have been assessed during the years ended December 31, 2025 and 2024. Basic and Diluted Loss per Share of Common Stock Basic loss per share is based on the weighted average number of shares of common stock outstanding for the period. Basic loss per share represents Net Loss Attributable to Common Stockholders divided by the weighted average number of shares of common stock outstanding for the period. Diluted loss per share is presented using the treasury stock method. The treasury stock method is a method of recognizing the use of proceeds that could be obtained upon exercise of options and warrants in computing diluted loss per share. The method assumes that any proceeds would be used to purchase common stock at the average market price during the period. Diluted loss per share represents Net Loss Attributable to Common Stockholders divided by diluted weighted average number of shares of common stock, which includes the average dilutive effect of all potentially dilutive securities outstanding for the period. Foreign Currency The Company’s reporting currency and the functional currency of its foreign operations is U.S. dollars. The Company’s Korean subsidiary maintains its financial statements in U.S. dollars. Monetary assets and liabilities denominated in foreign currencies are remeasured into U.S. dollars using the exchange rate prevailing at the balance sheet date. Gains and losses arising on remeasurement or settlement of foreign currency denominated transactions or balances are included in the determination of income. The Company has not entered into derivative instruments to offset the impact of foreign currency fluctuations. The total impact of foreign currency transaction losses for the years ended December 31, 2025 and 2024 was $ 37 and $ 179 , respectively. ​ Recent Accounting Pronouncements Income Taxes In December 2023, the Financial Accounting Standards Board (“FASB”) issued ASU No. 2023-09 Income Taxes (Topic 740) Improvements to Income Tax Disclosures. ASU 2023-09 requires companies to disclose, on an annual basis, specific categories in the effective tax rate reconciliation and provide additional information for reconciling items that meet a quantitative threshold. In addition, ASU 2023-09 requires companies to disclose additional information about income taxes paid. Effective January 1, 2025, the Company adopted ASU 2023-09 on a prospective basis. See “—Income Taxes” above and Note 13 – Income Taxes for more information. Income Statement In November 2024, the FASB issued ASU No. 2024-03 Income Statement – Reporting Comprehensive Income – Expense Disaggregation Disclosures (Subtopic 220-40) Disaggregation of Income Statement Expenses. ASU 2024-03 requires disclosure of specified information about certain costs and expenses in the notes to the financial statements. ASU 2024-03 will be effective for annual periods beginning after December 15, 2026 and interim periods beginning after December 15, 2027. ASU 2024-03 can be applied either prospectively to financial statements or retrospectively to any prior periods presented in the financial statements. The Company is evaluating the disclosure impact of ASU 2024-03. Financial Instruments - Credit Losses In July 2025, the FASB issued ASU No. 2025-05 Financial Instruments – Credit Losses (Topic 326). ASU 2025-05 clarifies guidance related to Topic 326 for current accounts receivable and current contract assets arising from transactions accounted for under Topic 606, Revenue from Contracts with Customers, allowing for a practical expedient that assumes that current conditions as of the balance sheet do not change for the remaining life of the asset. ASU 2025-05 is effective for annual reporting periods beginning after December 15, 2025, and interim reporting periods within those annual reporting periods, with early adoption permitted. The Company is evaluating the disclosure impact of ASU 2025-05. Solid Power, Inc. | 2025 Form 10-K | 57 Table of Contents Government Grants In December 2025, the FASB issued ASU No. 2025-10 Government Grants (Topic 832). ASU 2025-10 establishes authoritative guidance on the recognition, measurement and presentation of government received by business entities. The guidance is effective for annual reporting periods beginning after December 15, 2028, with early adoption permitted. The guidance is applied on a modified prospective, a modified retrospective, or a retrospective transition approach. The Company is currently evaluating the impact of adoption on the Consolidated Financial Statement and disclosures. Interim Reporting In December 2025, the FASB issued ASU No. 2025-11 Interim Reporting (Topic 270). ASU 2025-11 clarifies guidance related to Topic 270 for interim disclosure requirements. The objective of the amendment is to provide clarity about the current requirements rather than evaluate whether to expand or reduce interim disclosure requirements. ASU 2025-11 is effective for interim reporting periods beginning after December 15, 2027, with early adoption permitted. The Company is evaluating the disclosure impact of ASU 2025-11. The Company reviewed all other recently issued accounting pronouncements and concluded that they were either not applicable or not expected to have a significant impact on its Consolidated Financial Statements. Note 3 – Property, Plant, and Equipment Property, plant, and equipment are summarized as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ ​ 2025 ​ ​ ​ 2024 Production equipment ​ $ 43,203 ​ $ 41,750 Laboratory equipment ​ ​ 15,287 ​ ​ 12,611 Leasehold improvements ​ 73,369 ​ 73,114 Furniture and computer equipment ​ 4,711 ​ 4,298 Construction in progress ​ 6,858 ​ 5,141 Total cost ​ 143,428 ​ 136,914 Accumulated depreciation ​ ( 57,110 ) ​ ( 39,706 ) Net property, plant and equipment ​ $ 86,318 ​ $ 97,208 ​ Depreciation expenses for dedicated laboratory equipment and production equipment are charged to research and development. Depreciation expense related to office equipment, leasehold improvements, software and computer equipment are allocated between research and development and selling, general and administrative expenses based on the nature of use. Depreciation expenses related to property, plant, and equipment are summarized as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ ​ 2025 ​ ​ ​ 2024 ​ ​ ​ Depreciation expense ​ $ 18,400 ​ $ 16,449 ​ ​ In 2025, the Company was designing a continuous electrolyte production pilot line. As of December 31, 2025, detailed design for the line was substantially complete, and the Company expects the line to be commissioned by the end of 2026. In 2025, the Solid Power, Inc. | 2025 Form 10-K | 58 Table of Contents Company also expanded the capabilities of the electrolyte innovation center (the “EIC”) and the cell safety abuse lab. Construction in progress related to property, plant and equipment is summarized as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, Construction in progress 2025 ​ ​ ​ 2024 Continuous electrolyte pilot manufacturing line ​ $ 5,214 ​ $ 1,194 Cell safety abuse lab ​ ​ 94 ​ ​ 835 EIC ​ ​ 111 ​ ​ 1,292 Other capital projects ​ ​ 1,439 ​ ​ 1,820 Total construction in progress ​ $ 6,858 ​ $ 5,141 ​ ​ Solid Power, Inc. | 2025 Form 10-K | 59 Table of Contents Note 4 – Intangible Assets Intangible assets are summarized as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ ​ 2025 ​ ​ ​ 2024 ​ ​ Gross Carrying ​ Accumulated ​ Gross Carrying ​ Accumulated ​ ​ Amount ​ ​ ​ Amortization ​ ​ ​ Amount ​ ​ ​ Amortization Intangible assets: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Licenses ​ $ 149 ​ $ ( 78 ) ​ $ 149 ​ $ ( 69 ) Patents ​ ​ 261 ​ ​ ( 25 ) ​ ​ 135 ​ ​ ( 12 ) Patents pending ​ ​ 1,813 ​ — ​ 1,831 ​ — Trademarks ​ ​ 13 ​ ​ — ​ ​ 13 ​ ​ — Trademarks pending ​ ​ 33 ​ — ​ 25 ​ — Total intangible assets ​ $ 2,269 ​ $ ( 103 ) ​ $ 2,153 ​ $ ( 81 ) ​ Amortization expense for intangible assets is summarized as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ ​ 2025 ​ ​ ​ 2024 ​ Amortization expense ​ $ 22 ​ $ 15 ​ ​ Useful lives of intangible assets range from three to 20 years . Amortization expenses are expensed within research and development in Operating Expenses in the Company’s Consolidated Statements of Operations and Comprehensive Loss. During 2025, the Company concluded there were assets on the Consolidated Balance Sheets related to patent application costs for patents that the Company is no longer pursuing. As the carrying amount of the intangible asset was not recoverable and the carrying value exceeded its fair value, an impairment loss was recognized. The fair value of these identified patents was determined to be zero and therefore the full carrying value $ 748 was written off. As of December 31, 2025, the Company recognized $ 748 in impairment loss which is presented in research and development expense within the Consolidated Statements of Operations and Comprehensive Loss. Note 5 – Fair Value Measurements The carrying amounts of certain financial instruments, such as cash equivalents, accounts receivable, accounts payable, and accrued liabilities, approximate fair value due to their relatively short maturities. The difference between the amortized cost and fair value of available-for-sale securities as of December 31, 2025 was not material. Assets and Liabilities Measured and Recorded at Fair Value on a Recurring Basis The following table summarizes the asset type, balance sheet classification, maturity, and value of the Company’s marketable securities and investments in the Consolidated Balance Sheets. ​ ​ ​ ​ ​ ​ ​ ​ ​ Assets Balance Sheet Classification Maturity December 31, 2025 ​ December 31, 2024 Commercial Paper Marketable securities Due in 1 year or less $ 62,166 ​ $ 47,046 Corporate Bonds Marketable securities Due in 1 year or less ​ 122,941 ​ ​ 28,614 Government Bonds Marketable securities Due in 1 year or less ​ 39,053 ​ ​ — U.S. Treasuries Marketable securities Due in 1 year or less ​ 5,017 ​ ​ 17,124 ​ Total Marketable securities ​ $ 229,177 ​ $ 92,784 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Corporate Bonds Investments Due in 1 year to 5 years $ 63,187 ​ $ 173,369 Government Bonds Investments Due in 1 year to 5 years ​ 22,479 ​ ​ 35,904 Equity Method Investment Investments ​ ​ 1,331 ​ ​ 1,127 ​ Total Investments ​ $ 86,997 ​ $ 210,400 ​ ​ Solid Power, Inc. | 2025 Form 10-K | 60 Table of Contents As of December 31, 2025 and December 31, 2024, the Company’s financial assets and liabilities measured and recorded at fair value on a recurring basis were classified within the fair value hierarchy as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2025 ​ ​ ​ ​ ​ Level 1 ​ ​ ​ Level 2 ​ ​ ​ Level 3 ​ ​ ​ Total Assets Balance Sheet Classification ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Commercial paper Marketable securities ​ $ 62,167 ​ $ — ​ $ — ​ $ 62,167 Corporate bonds Marketable securities ​ $ 122,941 ​ $ — ​ $ — ​ $ 122,941 Government bonds Marketable securities ​ $ 39,053 ​ $ — ​ $ — ​ $ 39,053 U.S. treasuries Marketable securities ​ $ 5,017 ​ $ — ​ $ — ​ $ 5,017 Corporate bonds Investments ​ $ 63,187 ​ $ — ​ $ — ​ $ 63,187 Government bonds Investments ​ $ 22,479 ​ $ — ​ $ — ​ $ 22,479 Bifurcated embedded derivative Loan receivable from equity method investee ​ $ — ​ $ — ​ $ 584 ​ $ 584 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Liabilities ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Public Warrants Warrant liabilities ​ $ 9,911 ​ $ — ​ $ — ​ $ 9,911 Private Placement Warrants Warrant liabilities ​ $ — ​ $ 3,970 ​ $ — ​ $ 3,970 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2024 ​ ​ ​ ​ ​ Level 1 ​ ​ ​ Level 2 ​ ​ ​ Level 3 ​ ​ ​ Total Assets Balance Sheet Classification ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Commercial paper Marketable securities ​ $ 47,046 ​ $ — ​ $ — ​ $ 47,046 Corporate bonds Marketable securities ​ $ 28,614 ​ $ — ​ $ — ​ $ 28,614 Corporate bonds Investments ​ $ 173,369 ​ $ — ​ $ — ​ $ 173,369 Government bonds Investments ​ $ 35,904 ​ $ — ​ $ — ​ $ 35,904 U.S. treasuries Marketable securities ​ $ 17,124 ​ $ — ​ $ — ​ $ 17,124 Bifurcated embedded derivative Loan receivable from equity method investee ​ — ​ ​ — ​ ​ 584 ​ 584 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Liabilities ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Public Warrants Warrant liabilities ​ $ 5,537 ​ $ — ​ $ — ​ $ 5,537 Private Placement Warrants Warrant liabilities ​ $ — ​ $ 3,198 ​ $ — ​ $ 3,198 ​ The change in fair value of the Company’s marketable securities and investments are included in Other Comprehensive Income (Loss) in the Company’s Consolidated Statements of Operations and Comprehensive Loss. There were no transfers in and out of Level 3 fair value hierarchy during the years ended December 31, 2025 and 2024. The following table provides the available-for-sale securities purchased during the years ended December 31, 2025, and 2024. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the Years Ended December 31, ​ ​ ​ ​ 2025 ​ ​ ​ 2024 Available-for-sale securities purchased ​ $ 277,726 ​ $ 216,193 Solid Power, Inc. | 2025 Form 10-K | 61 Table of Contents ​ Fair Value of Bifurcated Embedded Derivative The fair value of the bifurcated embedded derivative (the “Derivative”) has been estimated using the with-and-without method as of December 31, 2025 and 2024 using Level 3 unobservable input; and Level 2 directly or indirectly observable inputs, including estimated credit rating, risk-free interest rates, discount rates utilized in expected future cash flows and expected future cash flows. The Company’s expectation of future cash flow is significant to the measurement of fair value. Material increases or decreases in any of those inputs may result in a significantly higher or lower estimated fair value measurement of the Derivative. See Note 11 – Related Party Transactions for more information. Fair Value of Warrants The fair value of the private placement warrants issued as part of the Company’s business combination in 2021 (the “Private Placement Warrants”) have been estimated using a Black-Scholes model as of December 31, 2025 and 2024. The estimated fair value of the Private Placement Warrants is determined using Level 2 directly or indirectly observable inputs. Inherent in a Black-Scholes model are assumptions related to expected stock-price volatility, expected life, risk-free interest rate, and dividend yield. Material increases (or decreases) in any of those inputs may result in a significantly higher (or lower) fair value measurement. The Company estimates the volatility of its Private Placement Warrants based on implied volatility from the Company’s publicly-traded warrants (the “Public Warrants” and, together with the Private Placement Warrants, the “Warrants”). The risk-free interest rate is based on the U.S. Treasury zero-coupon yield curve for a maturity similar to the expected remaining life of the Warrants. The dividend yield is based on the historical rate, which the Company anticipates remaining at zero. The fair value of the Public Warrants has been measured based on the quoted price of such warrants on the Nasdaq Stock Market, a Level 1 input. The following table provides quantitative information regarding Level 2 inputs used in the recurring valuation of the Private Placement Warrants as of their measurement dates. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ ​ 2025 ​ ​ ​ 2024 ​ Exercise price ​ $ 11.50 ​ $ 11.50 ​ Stock price ​ $ 4.25 ​ $ 1.89 ​ Volatility ​ 114.5 % 124.8 % Term (in years) ​ 0.94 ​ 1.94 ​ Risk-free rate ​ 3.43 % 4.16 % ​ The following table provides a rollforward (per Warrant) of the Public Warrants measured at fair value using Level 1 inputs and Private Placement Warrants measured at fair value using Level 2 inputs. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Public Warrants ​ Private Placement Warrants ​ ​ ​ ​ Level 1 Fair Value ​ ​ ​ Level 2 Fair Value December 31, 2024 ​ $ 0.42 ​ $ 0.52 Change in fair value ​ $ 0.29 ​ $ 0.22 December 31, 2025 ​ $ 0.71 ​ $ 0.74 ​ See Note 6 – Warrant Liabilities for more information. ​ ​ Note 6 –Warrant Liabilities The table below provides a summary of the outstanding Public and Private Placement Warrants. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ ​ 2025 ​ ​ ​ 2024 Public Warrants ​ ​ 13,958,836 ​ ​ 13,182,501 Private Placement Warrants ​ ​ 5,374,467 ​ ​ 6,150,802 ​ Solid Power, Inc. | 2025 Form 10-K | 62 Table of Contents Each whole Warrant entitles the holder thereof to purchase one share of common stock at a price of $ 11.50 per share, subject to customary adjustments. Only whole Warrants are exercisable. The Warrants became exercisable on January 7, 2022 and will expire on December 8, 2026. Redemption of Public Warrants When Price per Share of Common Stock Equals or Exceeds $ 18.00 The Company may redeem all of the outstanding Public Warrants: ● in whole and not in part; ● upon at least 30 days ’ prior written notice; ● at a price of $ 0.01 per Public Warrant; and ● if the last sale price of the Company’s common stock equals or exceeds $ 18.00 per share, subject to customary adjustments, for any 20 trading days within a 30 -trading day period ending on the third trading day prior to the date on which notice of the redemption is given. Redemption of Public Warrants When Price per Share of Common Stock Equals or Exceeds $ 10.00 The Company may redeem all of the outstanding Public Warrants: ● in whole and not in part; ● upon at least 30 days ’ prior written notice; ● at a price of $ 0.10 per Public Warrant, provided that holders will be able to exercise their Warrants on a cashless basis prior to redemption and receive a number of shares of the Company’s common stock determined in part by the redemption date and the “fair market value” of the common stock; and ● if the last sale price of the Company’s common stock equals or exceeds $ 10.00 per share, subject to customary adjustments, on the trading day prior to the date on which notice of redemption is given. The “fair market value” of the Company’s common stock means the average reported last sale price of the Company’s common stock for the ten trading days immediately following the date on which the notice of redemption is sent to the holders of Warrants. None of the Private Placement Warrants are redeemable by the Company so long as they are held by the initial purchasers of the Private Placement Warrants or their permitted transferees. ​ Note 7 – Stockholders’ Equity At-the-Market Offering On September 5, 2025, the Company entered into an Equity Distribution Agreement (the “Distribution Agreement”) with Oppenheimer & Co. Inc., serving as agent (“Oppenheimer”), with respect to an at-the-market offering program (the “ATM”) under which the Company may offer and sell, from time to time, shares of its common stock having an aggregate offering price of up to $ 150,000 through Oppenheimer. During the year ended December 31, 2025, the Company sold 18,023,085 shares of common stock at an average price of $ 5.06 per share under the Distribution Agreement, raising gross proceeds of $ 91,215 before deducting offering costs, commissions, and fees. Net proceeds to the Company totaled $ 88,762 after deducting offering costs, commissions, and fees. As of December 31, 2025, approximately $ 58,785 remained available for future sales under the Distribution Agreement. Stock Repurchase Program On January 23, 2024, the Company announced that its Board of Directors (the “Board”) approved a stock repurchase program authorizing the Company to purchase up to $ 50,000 of the Company’s outstanding common stock. Under the repurchase program, the Company may purchase shares of its common stock from time to time until the repurchase program expires on December 31, 2025. Solid Power, Inc. | 2025 Form 10-K | 63 Table of Contents The table below presents the number of shares repurchased and retired, the principal, commissions, and total cash paid to repurchase and retire shares of common stock, the excise tax, and the average purchase price per share for the years ended December 31, 2025 and 2024. The repurchased shares were subject to excise tax of 1 % of which is accounted for within Additional paid-in capital and accrued within Accounts payable and other current liabilities in the Consolidated Balance Sheets. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the Year Ended December 31, ​ ​ 2025 ​ 2024 Repurchased and retired shares of common stock ​ ​ 3,361,396 ​ ​ 5,704,401 Principal paid to repurchase and retire shares of common stock ​ $ 3,525 ​ $ 8,959 Commissions paid to repurchase and retire shares of common stock ​ $ 67 ​ $ 113 Total cash paid to repurchase and retire shares of common stock ​ $ 3,592 ​ $ 9,072 Excise tax accrued ​ $ — ​ $ 90 Average cost paid per share (including commissions) ​ $ 1.07 ​ $ 1.59 ​ ​ Note 8 – Stock-Based Compensation 2014 Plan and 2021 Plan Options granted under the Solid Power, Inc. 2014 Equity Incentive Plan (the “2014 Plan”) have a ten-year term and vest as to 1/4 th of these options after one year after the initial date of service of a service provider and with the balance of the options vesting in a series of 36 successive equal monthly installments following the first vesting date. Option awards under the 2014 Plan were granted with an exercise price equal to the fair market value of Solid Power Operating, Inc.’s common stock at the date of grant. Certain option awards issued under the 2014 Plan provide for accelerated vesting if there is a change in control (as defined in the plan agreements). Options granted under the Solid Power, Inc. 2021 Equity Incentive Plan (the “2021 Plan”) during 2022 have a ten-year term and vest as to 1/4 th of these options per year beginning one year after the initial date of service of a service provider. Options granted under the 2021 Plan starting 2023 have a ten-year term and vest as to 1/4 th of the options one year after the initial date of service of a service provider then 6.25 % per quarter thereafter. Option awards under the 2021 Plan were granted with an exercise price equal to the fair market value of the Company’s common stock at the date of grant. Certain option awards issued under the 2021 Plan provide for accelerated vesting if there is a change in control (as defined in the plan agreements). Effective April 1, 2022, the Company began granting RSUs in accordance with the terms of the 2021 Plan. The grant date fair value of RSUs awarded are determined based on the Company’s closing common share price on the Nasdaq on the grant date. RSU awards for employees granted during 2022 generally vest 25 % per year commencing on the first anniversary of the grant date. RSU awards for employees granted during 2024 and 2025 generally vest 25 % on the first anniversary of the grant date then 6.25 % per quarter thereafter. Vested RSU awards for employees are settled in shares of common stock. RSU awards upon initial service as a director vest in 12 equal quarterly installments. For initial service grants, vested RSUs are settled in common stock upon the earlier of the director no longer serving on the Board or the date the RSU has fully vested. Annual RSU awards to directors generally fully vest on the one-year anniversary of the grant date. Upon vesting, granted RSUs entitle the grantee to receive one share of common stock of the Company at no additional cost. Holders of unvested RSUs do not have voting or dividend rights. At December 31, 2025 and 2024, the Company had 6,496,068 and 11,241,546 shares of common stock underlying stock options outstanding under the 2014 Plan, respectively. No additional grants under the 2014 Plan are permitted. Beginning on January 1, 2022, the number of shares of common stock available for issuance under the 2021 Plan shall increase annually by an amount equal to the lesser of (i) 18,900,000 shares of common stock, (ii) five percent ( 5 %) of the total number of shares of common stock outstanding on the last day of the immediately preceding fiscal year, or (iii) a number of shares of common stock determined by the administrator no later than the last day of the immediately preceding fiscal year. On January 1, 2024 and 2025, the number of shares of common stock available for issuance under the 2021 Plan increased by 8,950,544 and 10,059,059 shares of common stock, respectively. As of December 31, 2025, and 2024, the 2021 Plan permitted the Company to grant up to 37,575,657 and 28,196,225 shares of common stock, respectively, to its employees, directors, and consultants, as designated by the Board. As of December 31, 2025 and 2024, the Company had 18,618,626 and 17,174,592 shares of common stock underlying options awards and RSU awards outstanding under the 2021 Plan, respectively. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the Years Ended December 31, ​ ​ ​ ​ 2025 ​ ​ ​ 2024 Option awards granted under 2021 Plan ​ ​ — ​ ​ 6,324,127 RSU awards granted under 2021 Plan ​ ​ 10,151,545 ​ ​ 6,792,700 ​ Solid Power, Inc. | 2025 Form 10-K | 64 Table of Contents Restricted Stock Grants to Dahae Executives On October 21, 2024, the Company issued 298,508 shares of restricted stock grants to Dahae executives pursuant to the provisions of Regulation S under the Securities Act of 1933, as amended. This issuance was not under any existing plan. The restricted stock grants vest over a four-year period, subject to forfeiture upon the applicable stockholder ceasing to provide services to Dahae or upon Dahae’s default on the financing instruments entered into between the Company and Dahae on October 21, 2024. No additional shares of restricted stock are authorized for issuance to Dahae executives. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the Years Ended December 31, ​ ​ ​ ​ 2025 ​ ​ ​ 2024 Restricted stock grants to Dahae Executives ​ ​ — ​ ​ 298,508 ​ Compensation Expense for Stock-Based Compensation The fair value of stock options and RSUs issued to employees and directors is recognized as compensation expense over the vesting period of the award. The fair value of the restricted stock grants issued to Dahae executives is recognized straight-line over the vesting period of the grant. The Company accounts for forfeitures as they occur. For the years ended December 31, 2025 and 2024, the Company recognized compensation costs totaling: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the Years Ended December 31, ​ ​ 2025 ​ ​ ​ 2024 Stock-based compensation costs related to RSUs ​ $ 6,344 ​ $ 5,662 Stock-based compensation costs related to stock options ​ 2,319 ​ 6,138 Stock-based compensation costs related to the ESPP ​ ​ 327 ​ ​ 172 Total equity-based compensation costs ​ $ 8,990 ​ $ 11,972 ​ The unrecognized future compensation costs as of December 30, 2025 and 2024 were $ 22,214 and $ 20,549 , respectively. The Company expects to recognize the future compensation cost over a weighted average period of 2.8 years, amortized over a straight-line basis. The Company records compensation across Operating Expenses within the following financial statement lines: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the Years Ended December 31, ​ ​ 2025 2024 Direct costs ​ $ — ​ $ 1,131 Research and development ​ ​ 3,553 ​ ​ 4,463 Selling, general and administrative ​ ​ 5,437 ​ ​ 6,378 Total equity-based compensation cost ​ $ 8,990 ​ $ 11,972 ​ ​ The fair value of restricted stock grants to Dahae executives is recognized over the vesting period. The Company recognized $ 91 and $ 22 within Share of net loss (income) of equity method investee in the Company’s Consolidated Statements of Operations and Comprehensive Loss for the years ended December 31, 2025 and 2024, respectively. Stock Options For purposes of determining the compensation cost, the fair value of each option award is estimated on the date of grant using a Black-Scholes option valuation model that uses the weighted-average assumptions noted in the following table. Expected volatilities are based on historical volatility of comparable companies. The Company uses historical data to estimate option exercise and employee termination within the valuation model. The risk-free rate for periods within the expected life of the option is based on the U.S. Treasury yield curve in effect at the time of grant. Solid Power, Inc. | 2025 Form 10-K | 65 Table of Contents During the year ended December 31, 2025, no stock options were granted. The fair value of each stock option grant during the year ended December 31, 2024 was estimated on the grant date using the Black-Scholes option pricing model with the following weighted-average assumptions used: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2024 Approximate risk‑free rate ​ ​ 4.23 % Volatility ​ ​ 48.1 % Average expected life (in years) ​ ​ 6 ​ Dividend yield ​ ​ 0 % Weighted‑average grant date fair value ​ $ 0.82 ​ Estimated fair value of total stock options granted ​ $ 5,175 ​ ​ A summary of stock option activity under the 2014 Plan and 2021 Plan for the year ended December 31, 2025 is presented below. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted-average ​ ​ ​ ​ ​ ​ ​ ​ ​ Remaining ​ ​ ​ ​ Number of ​ Weighted-average ​ Contractual Term ​ Aggregate Stock Options ​ ​ ​ Stock Options ​ ​ ​ Exercise Price ​ ​ ​ (in years) ​ Intrinsic Value Outstanding as of January 1, 2025 ​ 20,605,693 ​ $ 2.45 ​ 6.68 ​ 12,008 Granted ​ — ​ $ — ​ ​ ​ ​ Exercised ​ ( 3,339,162 ) ​ $ 1.57 ​ ​ ​ ​ Forfeited ​ ( 2,549,167 ) ​ $ 2.58 ​ ​ ​ ​ Expired ​ ( 2,397,290 ) ​ $ 4.97 ​ ​ ​ ​ Outstanding as of December 31, 2025 ​ 12,320,074 ​ $ 2.13 ​ 5.59 ​ 29,496 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Exercisable as of December 31, 2024 ​ 12,275,078 ​ $ 2.48 ​ 5.27 ​ 9,427 Exercisable as of December 31, 2025 ​ 9,769,633 ​ $ 2.19 ​ 4.94 ​ 23,427 ​ Restricted Stock Units The following table summarizes unvested RSUs as of December 31, 2025 and the changes for the year ended December 31, 2025. ​ ​ ​ ​ ​ ​ ​ ​ ​ Number of ​ ​ ​ Weighted-average ​ ​ RSUs ​ Grant Date Fair Value Balance at December 31, 2024 ​ 8,200,553 ​ ​ 3.10 Granted ​ 10,151,545 ​ ​ 1.75 Vested or Exercised ​ ( 3,008,674 ) ​ ​ 2.02 Forfeited ​ ( 2,015,234 ) ​ ​ 2.08 Balance at December 31, 2025 ​ 13,328,190 ​ ​ 1.78 ​ Restricted Stock Grants to Dahae Executives The following table summarizes activities of unvested restricted stock grants to Dahae executives and the changes for the year ended December 31, 2025. ​ ​ ​ ​ ​ ​ ​ ​ Number of ​ ​ ​ Weighted-average ​ ​ Restricted Stock Grants ​ Grant Date Fair Value Balance at December 31, 2024 ​ 238,806 ​ 1.23 Granted ​ — ​ ​ Vested ​ ( 110,671 ) ​ 1.23 Forfeited ​ — ​ ​ Balance at December 31, 2025 ​ 128,135 ​ 1.23 ​ Solid Power, Inc. | 2025 Form 10-K | 66 Table of Contents ESPP The Solid Power, Inc. 2021 Employee Stock Purchase Plan (“ESPP”) originated with 3,778,000 shares of common stock available for issuance. Beginning on January 1, 2022, the number of shares of common stock available for issuance under the ESPP shall increase annually by an amount equal to the lesser of (i) 3,778,000 shares of common stock (ii) one percent (1%) of the total number of shares of common stock outstanding on the last day of the immediately preceding fiscal year or (iii) a number of shares of common stock determined by the administrator no later than the last day of the immediately preceding fiscal year. On January 1, 2022, the number of shares of common stock available for issuance under the ESPP increased by 1,685,579 shares of common stock. There were no increases to the number of shares of common stock available for issuance under the ESPP on January 1, 2024 or 2025. As of December 31, 2025 and 2024, 4,430,644 and 4,788,691 shares remained available for issuance, respectively. The ESPP is intended to qualify as an “employee stock purchase plan” under Section 423 of the Internal Revenue Code. Substantially all employees are eligible to participate and, through payroll deductions, can purchase shares on dates determined by the administrator. However, with respect to the Section 423 Component (as defined in the ESPP), an employee may not be granted rights to purchase stock under the ESPP if the employee, immediately after the grant, would own (directly or through attribution) stock possessing 5 % or more of the total combined voting power or value of all classes of the Company’s common stock. The purchase price per share sold pursuant to the ESPP will be the lower of (i) 85 % of the fair market value of common stock on the enrollment or (ii) 85 % of the fair market value on the exercise date. Each offering period will span up to six months. Purchases may be up to 15 % of qualified compensation, with an annual limit of $ 25 and a limit of 5,000 shares per employee per offering period. Note 9 – Basic and Diluted Loss Per Share The table below sets forth the basic and diluted loss per share calculation for the years ended December 31, 2025 and 2024. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the Years Ended December 31, ​ ​ ​ 2025 ​ 2024 ​ Net loss attributable to common stockholders ​ $ ( 93,410 ) ​ $ ( 96,520 ) ​ Weighted average shares outstanding – basic and diluted ​ ​ 184,902,712 ​ ​ 179,397,332 ​ Basic and diluted loss per share ​ $ ( 0.51 ) ​ $ ( 0.54 ) ​ ​ Due to the net loss for the years ended December 31, 2025 and 2024, diluted loss per share was computed without consideration of potentially dilutive instruments as their inclusion would have been anti-dilutive. The table below sets forth (in shares) potentially dilutive securities excluded from the diluted loss per share calculation. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ ​ ​ ​ ​ 2025 ​ ​ ​ 2024 ​ Warrants ​ 19,333,303 19,333,303 ​ 2014 Plan & 2021 Plan - stock options ​ 14,576,084 22,969,681 ​ 2021 Plan - RSUs ​ 11,075,579 7,076,624 ​ ESPP - common stock ​ 34,736 ​ 60,037 ​ Dahae executives restricted stock grants - common stock ​ 186,224 ​ 8,658 ​ Total potentially dilutive securities ​ 45,205,926 ​ 49,448,303 ​ ​ ​ Note 10 – Leases The Company leases its facilities and certain equipment. Fixed rent escalates each year, and the Company is responsible for a portion of the landlords’ operating expenses such as property tax, insurance, and common area maintenance. The Company’s facility in Louisville, Colorado (“SP1”) is under a noncancelable operating lease with a maturity date in December 2029. The Company has the right to renew this operating lease for an additional five-year period. On September 1, 2021, the Company entered into an industrial operating lease agreement for its facility in Thornton, Colorado, or SP2, with the initial term through March 31, 2029. Under this operating lease, the Company has one option to renew for five years , which has been included in the calculation of lease liabilities and right-of-use assets as the exercise of the option was reasonably certain. As the renewal rent has not been negotiated, the Company used an estimated rent rate which approximated the fair market rent at adoption of ASC 842 on January 1, 2022 for the extension period. Solid Power, Inc. | 2025 Form 10-K | 67 Table of Contents The Company has certain equipment leases classified as finance leases as of December 31, 2025. In the Consolidated Balance Sheets, the Company records it right-of-use finance lease assets, net within Other assets, records its short-term finance lease liabilities within Accounts payable and other accrued liabilities, and records its long-term finance lease liabilities within Other liabilities. The Company’s leases do not have any contingent rent payments and do not contain residual value guarantees. The components of lease expense are as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the Years Ended December 31, ​ ​ 2025 ​ ​ ​ 2024 Finance lease costs: ​ ​ ​ ​ ​ Amortization of right-of-use assets ​ $ 476 ​ $ 232 Interest on lease liabilities ​ 26 ​ 46 Operating lease costs ​ 1,505 ​ 1,209 Total lease expense ​ $ 2,007 ​ $ 1,487 ​ ​ The components of cash flow information related to leases are as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the Years Ended December 31, ​ ​ ​ ​ ​ 2025 ​ ​ ​ 2024 ​ Operating outgoing cash flows – finance leases ​ $ 26 ​ $ 47 ​ Financing outgoing cash flows – finance leases ​ 280 ​ 377 ​ Operating outgoing cash flows – operating leases ​ 1,351 ​ 1,320 ​ Right-of-use assets obtained in exchange for new finance lease liabilities: ​ ​ ( 1 ) ​ ​ — ​ Right-of-use assets obtained in exchange for new and modified operating lease liabilities: ​ ​ 15 ​ ​ 1,005 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2025 Finance lease ​ ​ Weighted-average remaining lease term – finance leases (in years) 1.68 ​ Weighted-average discount rate – finance leases 6.8 % Operating lease ​ ​ Weighted-average remaining lease term – operating leases (in years) 7.08 ​ Weighted-average discount rate – operating leases 6.3 % ​ As of December 31, 2025, future minimum payments during the next five years and thereafter are as follows: ​ ​ ​ ​ ​ ​ ​ ​ Fiscal year ​ ​ ​ Finance Lease ​ ​ ​ Operating Lease 2026 ​ $ 179 ​ $ 1,403 2027 ​ ​ 85 ​ ​ 1,448 2028 ​ ​ 16 ​ ​ 1,494 2029 ​ ​ — ​ ​ 1,548 2030 ​ ​ — ​ ​ 903 Thereafter ​ ​ — ​ ​ 3,127 Total ​ ​ 280 ​ ​ 9,923 Less present value discount ​ ​ 14 ​ ​ 1,933 Total lease liabilities ​ $ 266 ​ $ 7,990 ​ ​ Note 11 – Related Party Transactions BMW of North America LLC During 2022, the Company amended its joint development agreement (“JDA”) with BMW of North America LLC (“BMW”) to provide a research and development-only license to certain of the Company’s intellectual property relating to cell manufacturing. The license allows, among other things, BMW to install a solid-state prototype cell manufacturing line based on the Company’s proprietary information. The license is limited to BMW’s research and development activities and may not be used for commercial battery cell production. During 2024, the Company further amended its JDA with BMW to extend the term of the JDA, revise the Solid Power, Inc. | 2025 Form 10-K | 68 Table of Contents payment schedule, and revise certain deliverables and the timing to achieve various milestone and development targets and confirm cell performance requirements. During 2024, BMW agreed to purchase certain cell materials from the Company for approximately $ 132 . During 2025, BMW agreed to purchase certain cell materials and electrolyte from the Company for approximately $ 225 . Before BMW’s installation of its cell manufacturing line, the Company and BMW have agreed to joint development and manufacturing activities at the Company’s facilities. Any intellectual property developed jointly by the Company and BMW at the Company’s facilities will be solely owned by the Company. To the extent intellectual property is jointly conceived elsewhere, the Company and BMW will jointly own such intellectual property. The intellectual property developed by us or BMW individually will be owned by such party. Both parties will have the right to utilize the other party’s technical improvements for research and development purposes only. The Company, with certain limitations, has the right to cause BMW to license BMW’s technical improvements to the Company for commercial purposes. BMW paid the Company $ 20,000 between December 2022 and June 2025, based on the achievement of milestones. BMW paid the Company $ 344 to purchase certain cell materials and electrolyte during 2025. For the year ended December 31, 2025, the Company recognized $ 189 of revenue from BMW related to certain cell materials and electrolyte and recorded $ 172 of deferred revenue of which $ 75 is related to the JDA and the remaining $ 97 is related to cash paid from BMW in advance of electrolyte delivered. For the year ended December 31, 2024, the Company recognized $ 5,410 of revenue from BMW. BMW Holding B.V., an affiliate of BMW, has the right to nominate a director for election to the Board as well as the right to designate an individual to attend meetings of the Board and its committees in a non-voting, observer capacity. Based on the Schedule 13D filed on December 20, 2021, BMW Holding B.V. is a beneficial owner of more than five percent of the Company’s common stock. Ford Motor Company During 2024, the Company amended its JDA with Ford Motor Company (“Ford”) to extend the term of the JDA and revise certain deliverables and the schedule for delivery to Ford during the term of the JDA. Ford was a beneficial owner of more than five percent of the Company’s common stock, based on the Schedule 13G/A filed on February 9, 2024. Dahae Energy Co., Ltd. During 2024, the Company entered into a series of transactions with Dahae, a strategic partner in the Republic of Korea. Dahae provides process engineering support for the Company’s pilot cell lines and is serving as the installer for installation of a pilot cell manufacturing line at SK On Co., Ltd.’s facility. The transactions included an equity interest, extinguishment of an existing promissory note, bond (the “Bond”) with detachable warrants (the “Detachable Warrants”) and a bifurcated embedded derivative (the “Derivative”), restricted stock grants to Dahae executives, and a term loan facility. The Company acquired a 20 % equity interest in Dahae for $ 656 (including $ 256 of transaction costs) and recorded the investment using the equity method of accounting. See Note 2 – Significant Accounting Policies for more information. The Company extinguished an existing promissory note from Dahae in exchange for the Bond with the Detachable Warrants and the Derivative. At the time of extinguishment, the Company recognized a loss of $ 760 for the difference between the promissory note balance prior to extinguishment and the fair value of the instruments and rights received. The Bond has an explicit interest rate of 3 %, maturity date of April 26, 2034, and par value of $ 4,448 . On October 21, 2024, the fair value of the Bond was $ 2,497 and the Derivative was recorded at a fair value upon acquisition of $ 584 . As of December 31, 2025, the Bond had an unamortized discount of $ 1,796 . The change in value of the Derivative between October 21, 2024 and December 31, 2025, was immaterial. The Bond and the Derivative are recorded in Loan receivable from equity method investee in the Consolidated Balance Sheets. The Company recorded the Detachable Warrants within Investments in the Consolidated Balance Sheets at a fair value upon acquisition of $ 607 . The Detachable Warrants are fully detachable from the Bond and can be exercised for shares of Dahae’s common stock. If the Company were to exercise the Detachable Warrants in full, the Company would own 40 % of the then outstanding shares of common stock of Dahae. As of December 31, 2025, there were no impairments or downward or upward adjustments to Detachable Warrants since acquisition. The Company granted 298,508 shares of restricted stock grants to Dahae executives. The restricted stock grants are subject to redemption at fair value once all shares are fully vested and any financing provided by the Company to Dahae has been repaid. As the restricted stock grants are contingently redeemable at fair value, the restricted stock grants are recorded within Mezzanine Equity in Solid Power, Inc. | 2025 Form 10-K | 69 Table of Contents the Consolidated Balance Sheets. To adjust these grants to redemption amounts at each reporting period, the Company remeasures the grants to their redemption value based on the price of the Company’s common stock, with a corresponding entry to the Company’s retained earnings. The remeasurement for the year ended December 31, 2025 was $ 323 . See Note 8 – Stock-Based Compensation for more information. The Company provided a term loan facility to Dahae. Dahae drew upon the facility on November 3, 2024, with a principal balance of $ 1,161 issued at par, explicit interest rate of 3 %, and maturity date of October 21, 2034. The loan is recorded in Loan receivable from equity method investee in the Consolidated Balance Sheets. All financing agreements between the Company and Dahae are collateralized by Dahae’s assets and a minority equity interest in Dahae. The Company has committed to provide up to $ 2,000 of additional financing to Dahae. The table below presents the summarized transactions recorded in the Consolidated Balance Sheets related to the Company’s equity method investment for the periods presented. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ ​ 2025 ​ ​ ​ 2024 Bond (a) ​ $ 3,236 ​ $ 3,105 Loan ​ ​ 1,161 ​ ​ 1,161 Warrants ​ ​ 607 ​ ​ 607 Equity method investment (b) ​ ​ 724 ​ ​ 520 Mezzanine equity ​ ​ 470 ​ ​ 34 ​ (a) Includes the value of the bifurcated embedded derivative related to a contingent early redemption of bond at its fair value of $ 584 . (b) As of December 31, 2025, this balance reflects the prior year ending balance plus the Company’s share of Dahae’s income of $ 179 and a currency translation gain of $ 24 related to the conversion from South Korean Won to U.S. dollar. The Company’s share of Dahae’s gain is recorded within Share of net loss (income) of equity method investee and the currency translation adjustment is recorded within Other Comprehensive Income in the Consolidated Statements of Operations and Comprehensive Loss. The table below presents the summarized transactions recorded in the Consolidated Statements of Operations and Comprehensive Loss related to the Company’s equity method investment. ​ ​ ​ ​ ​ ​ ​ ​ ​ For the Years Ended December 31, ​ ​ 2025 ​ ​ ​ 2024 Interest income ​ $ 299 ​ $ 105 Share of net loss (income) of equity method investee ​ ​ ( 65 ) ​ ​ 133 Other comprehensive income ​ ​ 24 ​ ​ 25 ​ During 2024, the Company incurred $ 9,342 of cost related to process engineering support provided by Dahae. During 2025, the Company incurred $ 12,461 of costs related to process engineering support provided by Dahae of which $ 4,540 was accrued to be paid. ​ Note 12 – Retirement Plans The Company sponsors a 401(k) plan for all employees. The plan provides for the Company to make a discretionary matching contribution. Contributions to the plan totaled $ 1,179 and $ 1,256 for the years ended December 31, 2025 and 2024, respectively. ​ ​ Solid Power, Inc. | 2025 Form 10-K | 70 Table of Contents Note 13 – Income Taxes The table below represents domestic versus foreign Loss before income tax expense (benefit). ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the Years Ended December 31, ​ ​ ​ ​ 2025 ​ 2024 U.S. ​ $ ( 86,277 ) ​ $ ( 93,543 ) Foreign ​ ​ ( 7,206 ) ​ ​ ( 1,650 ) Loss before income tax expense (benefit) ​ $ ( 93,483 ) ​ $ ( 95,193 ) ​ Income taxes included in the Consolidated Statements of Operations and Comprehensive Loss are detailed below. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the Years Ended December 31, ​ ​ ​ ​ ​ 2025 ​ 2024 ​ Current income tax expense (benefit) ​ ​ ​ ​ ​ ​ ​ Federal ​ $ — ​ $ — ​ State ​ ​ ( 1 ) ​ ​ 8 ​ Foreign ​ ​ ( 7 ) ​ ​ 1,186 ​ Deferred income tax expense (benefit) ​ ​ ​ ​ ​ ​ ​ Federal ​ ​ — ​ ​ — ​ State ​ ​ — ​ ​ — ​ Foreign ​ ​ — ​ ​ — ​ Total income tax expense (benefit) ​ $ ( 8 ) ​ $ 1,194 ​ ​ The table below represents net cash paid (refunds received) for income taxes. ​ ​ ​ ​ ​ For the Year Ended December 31, ​ 2025 Federal $ — Aggregated state and local jurisdictions ​ — Disaggregated state and local jurisdictions ​ ​ South Carolina ​ 3 District of Columbia ​ 2 California ​ 2 Connecticut ​ 1 Foreign (Republic of Korea) ​ ( 8 ) Net cash paid (refunds received) for income taxes $ — ​ Solid Power, Inc. | 2025 Form 10-K | 71 Table of Contents The tables below represent a reconciliation of the U.S. federal statutory income tax rate to effective tax rate. The Company has adopted the guidance in ASU 2023-09 on a prospective basis. The following table reflects the reconciliation rate for 2025 under the new guidance. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ ​ ​ ​ ​ 2025 ​ 2025 ​ ​ ​ Tax Expense ​ Effective Rate ​ U.S. federal statutory tax rate ​ ( 19,552 ) ​ 21 % ​ ​ ​ ​ ​ ​ State income taxes - net of federal income tax benefits (1) ​ ( 2 ) ​ — % Foreign tax effects ​ ​ ​ ​ ​ Republic of Korea ​ ​ ​ ​ ​ Valuation allowance ​ 2,400 ​ ( 2.58 ) % Other ​ ( 845 ) ​ 0.91 % Effects of changes in tax laws or rates enacted in the current period ​ — ​ — ​ Effect of cross-border tax laws ​ — ​ — % Tax credits ​ ​ ​ ​ ​ Research and development credit ​ ( 903 ) ​ 0.97 % Changes in valuation allowances ​ 16,772 ​ ( 18.01 ) % Nontaxable or nondeductible items ​ ​ ​ ​ ​ Stock-based compensation (2) ​ ( 429 ) ​ 0.46 % Mark-to-market warrant liabilities ​ 1,081 ​ ( 1.16 ) % Other ​ 667 ​ ( 0.72 ) % Changes in unrecognized tax benefits ​ 226 ​ ( 0.24 ) % Other adjustments ​ 577 ​ ( 0.62 ) ​ Effective tax rate ​ ( 8 ) ​ 0.01 % ​ (1) South Carolina and the District of Columbia make up the majority (greater than 50%) of the state income tax expense, net of federal income tax effect category. (2) The Company classifies windfalls and shortfalls relating to stock-based compensation as a nontaxable or nondeductible item. ​ The table below represents a reconciliation of the U.S. federal statutory tax rate to effective tax rate for the year ended December 31, 2024 under the prior guidance ​ ​ ​ ​ ​ U.S. federal statutory tax rate ​ 21.00 % State income taxes - net of federal income tax benefits ​ 0.82 % Foreign withholding taxes ​ ( 1.25 ) % Global tax rate differential ​ ( 0.21 ) % Permanent differences ​ ( 2.17 ) % Net change in valuation allowance ​ ( 21.79 ) % Research and development ​ 4.08 % Other ​ ( 1.74 ) % Effective tax rate ​ ( 1.26 ) % ​ ​ For the years ended December 31, 2025 and 2024, the effective tax rate was approximately 0.01 % and ( 1.26 )%, respectively. Differences between the statutory rate and the Company’s effective tax rate resulted from changes in valuation allowance and permanent differences for tax purposes in the treatment of certain nondeductible expenses. Solid Power, Inc. | 2025 Form 10-K | 72 Table of Contents The tax effects of temporary differences that give rise to significant portions of the deferred income tax assets and liabilities are presented below. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ December 31, ​ ​ ​ ​ ​ 2025 ​ 2024 ​ Deferred tax assets ​ ​ ​ ​ ​ ​ ​ Net operating loss ​ $ 51,517 ​ $ 30,446 ​ R&D credit ​ ​ 8,100 ​ ​ 7,423 ​ Stock compensation ​ ​ 3,363 ​ ​ 2,909 ​ Section 174 capitalization ​ ​ 26,203 ​ ​ 22,759 ​ ROU lease liability ​ ​ 2,018 ​ ​ 2,061 ​ Available-for-sale securities ​ ​ — ​ ​ ( 14 ) ​ Other ​ 1,670 ​ 2,441 ​ Total deferred tax asset ​ 92,871 ​ 68,025 ​ Valuation allowance ​ ( 90,181 ) ​ ( 64,744 ) ​ Net deferred tax assets ​ 2,690 ​ 3,281 ​ Deferred tax liabilities ​ ​ ​ ​ ​ Intangibles (non-goodwill) ​ $ ( 4 ) ​ $ ( 2 ) ​ Available-for-sale securities ​ ​ ( 82 ) ​ ​ — ​ Property, plant and equipment ​ ( 663 ) ​ ( 1,144 ) ​ Accretion ​ ​ ( 236 ) ​ ​ ( 307 ) ​ ROU asset ​ ​ ( 1,705 ) ​ ​ ( 1,828 ) ​ Total deferred tax liabilities ​ ( 2,690 ) ​ ( 3,281 ) ​ Total net deferred tax liability ​ $ — ​ $ — ​ ​ The ultimate realization of deferred tax assets is dependent upon the existence, or generation, of taxable income in the periods when those temporary differences and net operating loss carryovers are deductible. Management considers the scheduled reversal of deferred tax liabilities, taxes paid in carryover years, projected future taxable income, available tax planning strategies, and other factors in making this assessment. Based on available evidence, management does not believe it is more likely than not that all of the deferred tax assets will be realized. Accordingly, the Company has established a valuation allowance equal to the net realizable deferred tax assets. The valuation allowance increased by $ 25,438 in 2025. The valuation allowance relates entirely to the uncertainty regarding the realizability of the Company’s deferred tax assets. The Company had net operating losses and tax credit carryforwards as the year ended December 31, 2025 as follows: ​ ​ ​ ​ ​ ​ ​ ​ Amount ​ Expiration Years Net operating losses, federal (Pre January 1, 2018) $ 99 ​ 2037 Net operating losses, federal (Post December 31, 2017) ​ 42,242 ​ Indefinite Net operating losses, state ​ 6,889 ​ Various Net operating losses, foreign ​ 2,287 ​ 2039-2040 Tax Credits, federal ​ 8,100 ​ 2037-2045 ​ The following table summarizes the Company’s unrecognized tax benefits. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the Year Ended December 31, ​ ​ ​ ​ ​ 2025 ​ 2024 ​ Balance, beginning of year ​ $ 2,474 ​ $ 1,186 ​ Gross increases related to prior period tax position ​ — ​ 383 ​ Gross increases related to current period tax position ​ 566 ​ 905 ​ Gross decreases related to prior period tax position ​ ( 340 ) ​ — ​ Balance, end of year ​ $ 2,700 ​ $ 2,474 ​ ​ As of December 31, 2025 and 2024, unrecognized tax benefits of $ 2,700 and $ 2,474 , respectively, were recorded in other long-term liabilities and deferred tax liability. These unrecognized tax benefits would not impact the Company’s annual effective tax rate if recognized due to the Company’s valuation allowance. The Company recognizes interest and penalties, if any, related to unrecognized tax positions within the provision for income taxes in the accompanying Consolidated Statements of Operations and Comprehensive Loss. Solid Power, Inc. | 2025 Form 10-K | 73 Table of Contents As of December 31, 2025, undistributed earnings for non-U.S. subsidiaries are intended to be indefinitely reinvested in non-U.S. operations and therefore no U.S. deferred taxes have been recorded. The 2020 through 2024 tax years remain open to examination by the Internal Revenue Service and, with few exceptions, various other state tax agencies. These taxing authorities have the authority to examine those tax years until the applicable statutes of limitations expire. On July 4, 2025, the One Big Beautiful Bill Act (“OBBBA”) was enacted in the United States. The OBBBA includes, among other things the permanent extension of certain provisions of the U.S. Tax Cuts and Jobs Act of 2017, modifications to the United States’ international tax framework, restoration of favorable tax treatment for certain business provisions, and acceleration of the phase-out of EV credits. The OBBBA contains a variety of effective dates, with certain provisions effective in 2025 and others implemented through 2027. The OBBBA did not have a material impact on the reported results of operations. Note 14 – Contingencies The Company may be party to litigation from time to time in the normal course of business. The Company maintains insurance to cover certain actions and believes that resolution of such litigation will not have a material adverse effect on the Company. On December 3, 2024, two purported stockholders filed a putative class action against the former officers and directors of Decarbonization Plus Acquisition Corporation III (“DCRC”), including Erik Anderson; Riverstone Holdings, LLC; and related sponsors and entities (the “Hamilton Defendants”) in the Court of Chancery of the State of Delaware (Hamilton et al. v. Anderson et al., C.A. No. 2024-1241-JTL). The lawsuit alleges breach of fiduciary duties and unjust enrichment arising from the merger of Solid Power Operating, Inc. with a subsidiary of DCRC and seeks to recover unspecified damages and equitable relief. None of the Company, its subsidiaries, or its current officers or directors, except Mr. Anderson, is named as a defendant. The Hamilton Defendants have demanded indemnification and advancement of defense costs from the Company. Accordingly, it is reasonably possible that the Company could be liable for the legal fees, defense costs, judgments, and/or settlement fees incurred by certain of the Hamilton Defendants. The proceedings are subject to uncertainties inherent in the litigation process, and the Company cannot currently estimate a reasonably possible loss. Note 15 - Segment Disclosure The Company receives both government and collaborative revenue and earns revenue from U.S. and the Republic of Korea. The Company determined geographic area based on the country to which its legal entity is incorporated. The Company earned revenue from certain customers that each accounted for more than 10% of the Company’s total gross revenue for the years ended December 31, 2025, and 2024. The table below sets forth revenue by type, customer, and geographic area for the years ended December 31, 2025, and 2024. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the Years Ended December 31, Type of Revenue Customer Geographic Area 2025 ​ ​ ​ 2024 Government Customer A U.S. $ 2,174 ​ $ 2,472 Government Customer B U.S. ​ — ​ ​ 246 Government Customer C U.S. ​ 3,834 ​ ​ — Government Other U.S. ​ ( 50 ) ​ ​ 14 ​ ​ Total government ​ 5,958 ​ ​ 2,732 ​ ​ ​ ​ ​ ​ ​ ​ Collaborative Customer D U.S. $ 9,062 ​ $ 3,020 Collaborative Customer D Republic of Korea ​ 6,053 ​ ​ 8,760 Collaborative Customer E U.S. ​ 189 ​ ​ 5,410 Collaborative Other U.S. ​ 485 ​ ​ 217 ​ ​ Total collaborative ​ 15,789 ​ ​ 17,407 ​ ​ Total revenue and grant income $ 21,747 ​ $ 20,139 ​ ​ Note 16 – Subsequent Events On January 29, 2026, the Company completed a registered direct offering of 17,000,000 shares of its common stock, pre-funded warrants to purchase an aggregate of 5,807,018 shares of common stock, and warrants (the “Common Warrants”) to purchase up to an aggregate of 45,614,036 shares of common stock. The common stock was purchased at a price of $ 5.70 per share and Solid Power, Inc. | 2025 Form 10-K | 74 Table of Contents accompanying two Common Warrants and the pre-funded warrants were purchased at a price of $ 5.6999 per pre-funded warrant and accompanying two Common Warrants. The Common Warrants issued are immediately exercisable at an exercise price of $ 7.25 per share and will expire on January 31, 2033. Proceeds, net of fees before expenses, received by the Company totaled $ 122,199 . The Company intends to use the net proceeds from the registered direct offering for working capital and general corporate purposes. Item 9. Changes in and Disagreements With Accountants on Accounting and Financial Disclosure None.