Significant Accounting Policies	6 Months Ended
Jun. 30, 2025
Significant Accounting Policies
Significant Accounting Policies	Note 2 – Significant Accounting Policies The significant accounting policies followed by the Company are set forth in Note 2 – Significant Accounting Policies to the Company’s financial statements included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2024 (the “2024 Form 10-K”) and are supplemented by the Notes to the Condensed Consolidated Financial Statements (Unaudited) in this Report (the “Notes”). The financial statements included in this Quarterly Report on Form 10-Q (including the Notes) should be read in conjunction with the 2024 Form 10-K. Basis of Presentation and Principles of Consolidation The accompanying unaudited condensed consolidated financial statements of the Company have been prepared on the basis of U.S. generally accepted accounting principles (“GAAP”) and reflect all adjustments of a normal recurring nature, which are, in the opinion of management, necessary for a fair presentation of the consolidated financial position and results of operations at, and for, the periods presented. The preparation of unaudited condensed consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect amounts reported in the unaudited condensed consolidated financial statements. Actual results could differ from those estimates. All dollar amounts presented herein are in U.S. dollars and are in thousands, except par value and share and per share amounts. The accompanying unaudited condensed 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 the activities of the VIE that most significantly impacts 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 exercise 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 relationships 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 Condensed Consolidated Balance Sheets and separately within Share of net (income) loss of equity method investee in the Condensed Consolidated Statements of Operations and Comprehensive Loss and within Cash Flows from Investing Activities in the Condensed Consolidated Statements of Cash Flows. Available-for-Sale Securities 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 6 – Fair Value Measurement for more information. 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. 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 this adjustment because it believes using the cost-to-cost method provides more accurate reflection of how performance is satisfied over time. This adjustment is treated as a change in estimate beginning on January 1, 2025, and prior period amounts will not be adjusted. The Company expenses contract fulfillment costs as incurred. The Company estimates 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 expected value 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. The Company recognizes revenue from cooperative agreements with the government in cost contracts on the basis of costs incurred during the period and for 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. On January 21, 2025, Solid Power Operating, Inc. 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 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 Condensed 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. Reclassification of Prior Year Presentation Certain prior period amounts have been reclassified to conform to current period presentation in the accompanying unaudited condensed consolidated financial statements. Beginning in January 2025, reclassifications have been made to prior year amounts within the Condensed Consolidated Balance Sheets 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 the reported results of operations. 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 Condensed 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 as classified and presented in the Condensed Consolidated Statements of Operations and Comprehensive Loss. Recent Accounting Pronouncements 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. ASU 2023-09 will be effective for annual periods beginning January 1, 2025 and will be applied on a prospective basis with the option to apply the standard retrospectively. The Company is evaluating the impact. 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 impact of this guidance on its disclosure.

Significant Accounting Policies

6 Months Ended

Jun. 30, 2025

Note 2 – Significant Accounting Policies

The significant accounting policies followed by the Company are set forth in Note 2 – Significant Accounting Policies to the Company’s financial statements included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2024 (the “2024 Form 10-K”) and are supplemented by the Notes to the Condensed Consolidated Financial Statements (Unaudited) in this Report (the “Notes”). The financial statements included in this Quarterly Report on Form 10-Q (including the Notes) should be read in conjunction with the 2024 Form 10-K.

Basis of Presentation and Principles of Consolidation

The accompanying unaudited condensed consolidated financial statements of the Company have been prepared on the basis of U.S. generally accepted accounting principles (“GAAP”) and reflect all adjustments of a normal recurring nature, which are, in the opinion of management, necessary for a fair presentation of the consolidated financial position and results of operations at, and for, the periods presented. The preparation of unaudited condensed consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect amounts reported in the unaudited condensed consolidated financial statements. Actual results could differ from those estimates. All dollar amounts presented herein are in U.S. dollars and are in thousands, except par value and share and per share amounts. The accompanying unaudited condensed 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 the activities of the VIE that most significantly impacts 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 exercise 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 relationships 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 Condensed Consolidated Balance Sheets and separately within Share of net (income) loss of equity method investee in the Condensed Consolidated Statements of Operations and Comprehensive Loss and within Cash Flows from Investing Activities in the Condensed Consolidated Statements of Cash Flows.

Available-for-Sale Securities

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 6 – Fair Value Measurement for more information.

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. 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 this adjustment because it believes using the cost-to-cost method provides more accurate reflection of how performance is satisfied over time. This adjustment is treated as a change in estimate beginning on January 1, 2025, and prior period amounts will not be adjusted. The Company expenses contract fulfillment costs as incurred.

The Company estimates 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 expected value 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.

The Company recognizes revenue from cooperative agreements with the government in cost contracts on the basis of costs incurred during the period and for 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.

On January 21, 2025, Solid Power Operating, Inc. 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 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 Condensed 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.

Reclassification of Prior Year Presentation

Certain prior period amounts have been reclassified to conform to current period presentation in the accompanying unaudited condensed consolidated financial statements. Beginning in January 2025, reclassifications have been made to prior year amounts within the Condensed Consolidated Balance Sheets 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 the reported results of operations.

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 Condensed 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 as classified and presented in the Condensed Consolidated Statements of Operations and Comprehensive Loss.

Recent Accounting Pronouncements

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. ASU 2023-09 will be effective for annual periods beginning January 1, 2025 and will be applied on a prospective basis with the option to apply the standard retrospectively. The Company is evaluating the impact.

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 impact of this guidance on its disclosure.