Solid Power (SLDP) 10-Q 8 Nov 24 2024 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2024	Nov. 06, 2024
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Sep. 30, 2024
Document Transition Report	false
Securities Act File Number	001-40284
Entity Registrant Name	SOLID POWER, INC.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	86-1888095
Entity Address, Address Line One	486 S. Pierce Ave., Suite E
Entity Address, City or Town	Louisville
Entity Address, State or Province	CO
Entity Address, Postal Zip Code	80027
City Area Code	303
Local Phone Number	219-0720
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		180,387,669
Entity Central Index Key	0001844862
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2024
Document Fiscal Period Focus	Q3
Amendment Flag	false
Common stock
Title of 12(b) Security	Common stock, par value $0.0001 per share
Trading Symbol	SLDP
Security Exchange Name	NASDAQ
Warrants, each whole warrant exercisable for one share of common stock at an exercise price of $11.50
Title of 12(b) Security	Warrants, each whole warrant exercisable for one share of common stock at an exercise price of $11.50
Trading Symbol	SLDPW
Security Exchange Name	NASDAQ

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Current Assets
Cash and cash equivalents	$ 37,969	$ 34,537
Marketable securities	94,041	141,505
Contract receivables	2,614	1,553
Prepaid expenses and other current assets	5,280	5,523
Total current assets	139,904	183,118
Long-Term Assets
Property, plant and equipment, net	99,787	99,156
Right-of-use operating lease assets, net	6,832	7,154
Right-of-use finance lease assets, net	914	1,088
Investments	216,062	239,566
Intangible assets, net	1,953	1,650
Other assets	5,428	1,060
Total long-term assets	330,976	349,674
Total assets	470,880	532,792
Current Liabilities
Accounts payable and other accrued liabilities	7,030	6,455
Deferred revenue	6,735	1
Deferred revenue from related parties		828
Accrued compensation	5,562	7,590
Operating lease liabilities	690	626
Finance lease liabilities	329	379
Total current liabilities	20,346	15,879
Long-Term Liabilities
Warrant liabilities	2,434	4,227
Operating lease liabilities	7,469	7,996
Finance lease liabilities	319	552
Other liabilities	862	803
Total long-term liabilities	11,084	13,578
Total liabilities	31,430	29,457
Stockholders' Equity
Common Stock, $0.0001 par value; 2,000,000,000 shares authorized; 179,633,575 and 179,010,884 shares issued and outstanding as of September 30, 2024 and December 31, 2023, respectively	18	18
Additional paid-in capital	589,062	588,515
Accumulated deficit	(150,539)	(84,639)
Accumulated other comprehensive income (loss)	909	(559)
Total stockholders' equity	439,450	503,335
Total liabilities and stockholders' equity	$ 470,880	$ 532,792

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Parenthetical) - $ / shares	Sep. 30, 2024	Dec. 31, 2023
Condensed Consolidated Balance Sheets
Common stock, par value	$ 0.0001	$ 0.0001
Common stock, shares authorized	2,000,000,000	2,000,000,000
Common stock, shares issued	179,633,575	179,010,884
Common stock, shares outstanding	179,633,575	179,010,884

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations and Comprehensive Loss (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Condensed Consolidated Statements of Operations and Comprehensive Loss (Unaudited)
Revenue	$ 4,651	$ 6,366	$ 15,679	$ 15,063
Operating Expenses
Direct costs	6,973	7,183	16,700	20,354
Research and development	17,319	14,236	54,718	40,391
Selling, general and administrative	7,950	6,444	24,570	19,307
Total operating expenses	32,242	27,863	95,988	80,052
Operating Loss	(27,591)	(21,497)	(80,309)	(64,989)
Nonoperating Income and Expense
Interest income	4,251	5,213	13,707	15,041
Change in fair value of warrant liabilities	1,591	1,155	1,793	3,480
Interest expense	(11)	(13)	(37)	(39)
Other expense	(283)		(167)
Total nonoperating income and expense	5,548	6,355	15,296	18,482
Pretax Loss	(22,043)	(15,142)	(65,013)	(46,507)
Income tax expense	376		887
Net Loss Attributable to Common Stockholders	(22,419)	(15,142)	(65,900)	(46,507)
Other Comprehensive Income (Loss)	2,058	(215)	1,468	2
Comprehensive Loss Attributable to Common Stockholders	$ (20,361)	$ (15,357)	$ (64,432)	$ (46,505)
Basic loss per share	$ (0.13)	$ (0.08)	$ (0.37)	$ (0.26)
Diluted loss per share	$ (0.13)	$ (0.08)	$ (0.37)	$ (0.26)
Weighted average shares outstanding - Basic	179,160,488	178,388,926	179,177,452	177,800,915
Weighted average shares outstanding - Diluted	179,160,488	178,388,926	179,177,452	177,800,915

Condensed Consolidated Statem_2

Condensed Consolidated Statement of Stockholders' Equity (Unaudited) - USD ($) $ in Thousands	Common Stock	Additional paid-in capital	Accumulated deficit	Accumulated Other Comprehensive Loss	Total
Balance at the beginning at Dec. 31, 2022	$ 18	$ 577,603	$ (19,090)	$ (3,159)	$ 555,372
Balance at the beginning (in shares) at Dec. 31, 2022	176,007,184
Changes in stockholder's equity
Net loss			(31,363)		(31,363)
Withholding of employee taxes related to stock-based compensation		(111)	84		(27)
Shares of common stock issued under ESPP		214			214
Shares of common stock issued under ESPP (in shares)	129,928
Shares of common stock issued for vested RSUs (in shares)	163,148
Stock options exercised		183			183
Stock options exercised (in shares)	2,026,630
Stock-based compensation expense		5,145			5,145
Unrealized gain (loss) on marketable securities				(213)	(213)
Balance at the end at Jun. 30, 2023	$ 18	583,034	(50,369)	(3,372)	529,311
Balance at the end (in shares) at Jun. 30, 2023	178,326,890
Balance at the beginning at Dec. 31, 2022	$ 18	577,603	(19,090)	(3,159)	555,372
Balance at the beginning (in shares) at Dec. 31, 2022	176,007,184
Changes in stockholder's equity
Net loss					(46,507)
Shares of common stock issued under ESPP (in shares)	129,928
Shares of common stock issued for vested RSUs (in shares)	195,590
Stock options exercised (in shares)	2,084,695
Balance at the end at Sep. 30, 2023	$ 18	586,347	(65,596)	(3,157)	517,612
Balance at the end (in shares) at Sep. 30, 2023	178,417,397
Balance at the beginning at Jun. 30, 2023	$ 18	583,034	(50,369)	(3,372)	529,311
Balance at the beginning (in shares) at Jun. 30, 2023	178,326,890
Changes in stockholder's equity
Net loss			(15,142)		(15,142)
Withholding of employee taxes related to stock-based compensation			(85)		(85)
Shares of common stock issued for vested RSUs (in shares)	32,442
Stock options exercised		11			11
Stock options exercised (in shares)	58,065
Stock-based compensation expense		3,302			3,302
Unrealized gain (loss) on marketable securities				215	215
Balance at the end at Sep. 30, 2023	$ 18	586,347	(65,596)	(3,157)	517,612
Balance at the end (in shares) at Sep. 30, 2023	178,417,397
Balance at the beginning at Dec. 31, 2023	$ 18	588,515	(84,639)	(559)	503,335
Balance at the beginning (in shares) at Dec. 31, 2023	179,010,884
Changes in stockholder's equity
Net loss			(43,481)		(43,481)
Withholding of employee taxes related to stock-based compensation		(479)			(479)
Shares of common stock issued under ESPP		238			238
Shares of common stock issued under ESPP (in shares)	187,614
Shares of common stock issued for vested RSUs (in shares)	851,216
Stock options exercised		197			197
Stock options exercised (in shares)	3,590,897
Shares of common stock repurchased	(5,000,000)
Repurchase and retirement of shares of common stock		(8,356)			(8,356)
Stock-based compensation expense		5,914			5,914
Unrealized gain (loss) on marketable securities				(590)	(590)
Balance at the end at Jun. 30, 2024	$ 18	586,029	(128,120)	(1,149)	456,778
Balance at the end (in shares) at Jun. 30, 2024	178,640,611
Balance at the beginning at Dec. 31, 2023	$ 18	588,515	(84,639)	(559)	503,335
Balance at the beginning (in shares) at Dec. 31, 2023	179,010,884
Changes in stockholder's equity
Net loss					$ (65,900)
Shares of common stock issued under ESPP (in shares)	187,614
Shares of common stock issued for vested RSUs (in shares)	1,012,058
Stock options exercised (in shares)	4,423,019
Shares of common stock repurchased	(5,000,000)				(5,000,000)
Repurchase and retirement of shares of common stock					$ (8,355)
Balance at the end at Sep. 30, 2024	$ 18	589,062	(150,539)	909	439,450
Balance at the end (in shares) at Sep. 30, 2024	179,633,575
Balance at the beginning at Jun. 30, 2024	$ 18	586,029	(128,120)	(1,149)	456,778
Balance at the beginning (in shares) at Jun. 30, 2024	178,640,611
Changes in stockholder's equity
Net loss			(22,419)		(22,419)
Withholding of employee taxes related to stock-based compensation		(75)			(75)
Shares of common stock issued for vested RSUs (in shares)	160,842
Stock options exercised		35			$ 35
Stock options exercised (in shares)	832,122
Shares of common stock repurchased					0
Stock-based compensation expense		3,073			$ 3,073
Unrealized gain (loss) on marketable securities				2,058	2,058
Balance at the end at Sep. 30, 2024	$ 18	$ 589,062	$ (150,539)	$ 909	$ 439,450
Balance at the end (in shares) at Sep. 30, 2024	179,633,575

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023
Cash Flows from Operating Activities
Net loss	$ (65,900)	$ (46,507)
Adjustments to reconcile net loss to net cash and cash equivalents from operating activities:
Depreciation and amortization	11,991	7,805
Amortization of right-of-use assets	642	566
Stock-based compensation expense	8,987	8,447
Change in fair value of warrant liabilities	(1,793)	(3,480)
Accretion of discounts on other long-term liabilities	52
Amortization of premiums and accretion of discounts on marketable securities	(6,260)	(8,297)
Change in operating assets and liabilities that provided (used) cash and cash equivalents:
Contract receivables	(1,061)	(1,403)
Contract receivables from related parties		(5,048)
Prepaid expenses and other assets	707	297
Accounts payable and other accrued liabilities	(664)	207
Deferred revenue	6,734	(50)
Deferred revenue from related parties	(828)	(4,000)
Accrued compensation	(2,027)	218
Operating lease liabilities	(610)	(406)
Net cash and cash equivalents used in operating activities	(50,030)	(51,651)
Cash Flows from Investing Activities
Purchases of property, plant and equipment	(11,236)	(29,526)
Purchases of marketable securities and investments	(174,040)	(256,584)
Proceeds from sales of marketable securities and investments	252,177	315,493
Cash paid for note receivable to an independent contractor	(4,448)
Purchases of intangible assets	(314)	(428)
Net cash and cash equivalents provided by investing activities	62,139	28,955
Cash Flows from Financing Activities
Payments of debt		(7)
Proceeds from exercise of stock options	232	194
Proceeds from issuance of shares of common stock under the ESPP	238	214
Cash paid for withholding of employee taxes related to stock-based compensation	(554)	(111)
Repurchase of shares of common stock	(8,274)
Payments on finance lease liabilities	(319)	(259)
Net cash and cash equivalents provided by (used in) financing activities	(8,677)	31
Net decrease in cash and cash equivalents	3,432	(22,665)
Cash and cash equivalents at beginning of period	34,537	50,123
Cash and cash equivalents at end of period	37,969	27,458
Supplemental information
Cash paid for interest	37	39
Accrued capital expenditures	$ 2,041	$ 2,309

Nature of Business

Nature of Business	9 Months Ended
	Sep. 30, 2024
Nature of Business
Nature of Business	Note 1 – Nature of Business Solid Power is developing solid-state battery technology for the EV and other markets. The Company’s planned business model is to manufacture and sell its proprietary electrolyte and to license its cell designs and manufacturing processes.

Significant Accounting Policies

Significant Accounting Policies	9 Months Ended
	Sep. 30, 2024
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 2023 Form 10-K and are supplemented by the Notes. The financial statements included in this Report (including the Notes) should be read in conjunction with the 2023 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 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. Additionally, certain prior period amounts have been reclassified to conform to current period presentation in the accompanying unaudited condensed consolidated financial statements. Recent Accounting Pronouncements Income Taxes In December 2023, the FASB issued ASU 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 disclosure impact of ASU 2023-09. Segment Reporting In November 2023, the FASB issued ASU 2023-07 Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures. Among other new disclosure requirements, ASU 2023-07 requires companies to disclose significant segment expenses that are regularly provided to the chief operating decision maker, or CODM. ASU 2023-07 will be effective for annual periods beginning on January 1, 2024 and interim periods beginning on January 1, 2025. ASU 2023-07 must be applied retrospectively to all prior periods presented in the financial statements. The Company is currently evaluating the provisions and impact this ASU will have when adopted for the year ended December 31, 2024 and anticipates that it may result in additional required disclosures in the Company’s consolidated financial statements.

Property, Plant and Equipment

Property, Plant and Equipment	9 Months Ended
	Sep. 30, 2024
Property, Plant and Equipment
Property, Plant and Equipment	Note 3 – Property, Plant and Equipment Property, plant and equipment are summarized as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, 2024 December 31, 2023 ​ Production equipment ​ $ 40,328 ​ $ 36,086 ​ Laboratory equipment ​ ​ 11,524 ​ ​ 9,910 ​ Leasehold improvements ​ 70,793 ​ 59,109 ​ Furniture and computer equipment ​ 4,046 ​ 3,915 ​ Construction in progress ​ 8,585 ​ 13,650 ​ Total cost ​ 135,276 ​ 122,670 ​ Accumulated depreciation ​ (35,489) ​ (23,514) ​ Net property and equipment ​ $ 99,787 ​ $ 99,156 ​ ​ Depreciation expenses for dedicated laboratory equipment and production equipment are charged to research and development. The other depreciation expenses are included in the Company’s overhead and are allocated across Operating Expenses based on Company personnel costs incurred. Depreciation expense related to property, plant and equipment are summarized as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended September 30, ​ Nine Months Ended September 30, ​ ​ 2024 2023 ​ 2024 2023 ​ Depreciation expense ​ $ 4,014 ​ $ 2,896 ​ $ 11,980 ​ $ 7,794 ​ ​ The Company expanded its electrolyte production to produce larger quantities of electrolyte required to feed cell-production lines and continue research and development efforts at SP2. The Company began producing electrolyte at SP2 in 2023 . The Company has also built an electrolyte innovation center, or EIC, at SP2 to improve and test electrolyte manufacturing processes. The Company placed most of the lab into service in the three months ended September 30, 2024 and expects to place the remaining portion in service by the end of 2024. ​ ​ ​ ​ ​ ​ ​ ​ Construction in progress ​ September 30, 2024 ​ December 31, 2023 ​ SP1 - Capital projects ​ $ 4,722 ​ $ 2,298 ​ SP2 - Increased scale electrolyte production ​ ​ 3,863 ​ ​ 11,352 ​ Total ​ $ 8,585 ​ $ 13,650 ​ ​

Intangible Assets

Intangible Assets	9 Months Ended
	Sep. 30, 2024
Intangible Assets
Intangible Assets	Note 4 – Intangible Assets Intangible assets of the Company are summarized as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, 2024 December 31, 2023 ​ ​ ​ Gross Carrying ​ Accumulated ​ Gross Carrying ​ Accumulated ​ ​ Amount Amortization Amount Amortization ​ Intangible assets: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Licenses ​ $ 149 ​ $ (67) ​ $ 149 ​ $ (61) ​ Patents ​ ​ 135 ​ ​ (10) ​ ​ 92 ​ ​ (5) ​ Patents pending ​ 1,708 ​ — ​ 1,444 ​ — ​ Trademarks ​ ​ 13 ​ ​ — ​ ​ 13 ​ ​ — ​ Trademarks pending ​ 25 ​ — ​ 18 ​ — ​ Total amortized intangible assets ​ $ 2,030 ​ $ (77) ​ $ 1,716 ​ $ (66) ​ ​ ​ Amortization expense for intangible assets is summarized as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended September 30, ​ Nine Months Ended September 30, ​ 2024 2023 ​ 2024 2023 Amortization expense ​ $ 4 ​ $ 3 ​ $ 11 ​ $ 11 ​ ​ Useful lives of intangible assets range from three to 20 years . Amortization expenses are allocated ratably across Operating Expenses based on Company personnel costs incurred.

Collaborative Arrangement

Collaborative Arrangement	9 Months Ended
	Sep. 30, 2024
Collaborative Arrangement
Collaborative Arrangement	Note 5 – Collaborative Arrangement On January 10, 2024, the Company entered into the SK On Agreements. The Company determined the SK On Agreements should be combined and evaluated as a single contract. The SK On Agreements were determined to be a collaborative arrangement in accordance with ASC Topic 808, Collaborative Arrangements , and revenue recognition is recorded by analogy to ASC Topic 606, Revenue from Contracts with Customers . The Company determined the SK On Agreements represent a single, combined performance obligation. Collaborative revenue is recognized over time using the input measurement method utilizing incurred labor hours in relation to total labor hours anticipated to satisfy the combined performance obligation. The Company will expense contract fulfillment costs as incurred.

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2024
Fair Value Measurements
Fair Value Measurements	Note 6 – Fair Value Measurements The Company considers all highly liquid instruments with original maturities of less than 90 days to be cash equivalents. The carrying amounts of certain financial instruments, such as cash equivalents, short-term investments, accounts receivable, accounts payable, and accrued liabilities, approximate fair value due to their relatively short maturities. Level 1 inputs are quoted prices (unadjusted) in active markets for identical assets or liabilities that a reporting entity can access at the measurement date. Level 2 inputs are inputs other than quoted prices included within Level 1 that are observable for the asset or liability, either directly or indirectly. Level 3 inputs are unobservable inputs for assets or liabilities. Assets and Liabilities Measured and Recorded at Fair Value on a Recurring Basis As of September 30, 2024 and December 31, 2023, 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: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, 2024 ​ Level 1 Level 2 Level 3 Total Assets ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Commercial Paper ​ $ 44,464 ​ $ — ​ $ — ​ $ 44,464 Corporate Bonds ​ $ 216,075 ​ $ — ​ $ — ​ $ 216,075 Government Bonds ​ $ 32,618 ​ $ — ​ $ — ​ $ 32,618 U.S. Treasuries $ 16,946 ​ $ — ​ $ — $ 16,946 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Liabilities ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Public Warrants ​ $ 1,450 ​ $ — ​ $ — ​ $ 1,450 Private Placement Warrants ​ $ — ​ $ 984 ​ $ — ​ $ 984 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2023 ​ Level 1 Level 2 Level 3 Total Assets ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Commercial Paper ​ $ 84,909 ​ $ — ​ $ — ​ $ 84,909 Corporate Bonds ​ $ 239,473 ​ $ — ​ $ — ​ $ 239,473 Government Bonds ​ $ 56,689 ​ $ — ​ $ — ​ $ 56,689 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Liabilities ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Public Warrants ​ $ 2,505 ​ $ — ​ $ — ​ $ 2,505 Private Placement Warrants ​ $ — ​ $ 1,722 ​ $ — ​ $ 1,722 ​ The change in fair value of the Company’s marketable securities and investments are included in other comprehensive income (loss). There were no transfers in and out of Level 3 fair value hierarchy during the three or nine months ended September 30, 2024 or year ended December 31, 2023. During the nine months ended September 30, 2024, the Company purchased $174,040 of marketable securities and investments. Fair Value of Warrants The fair value of the Private Placement Warrants has been estimated using a Black-Scholes model as of September 30, 2024 and December 31, 2023 Consolidated Balance Sheet dates. 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 Public Warrants and from historical volatility of the Company’s common stock. 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: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, 2024 December 31, 2023 Exercise price ​ $ 11.50 ​ $ 11.50 ​ Stock price ​ $ 1.35 ​ $ 1.45 ​ Volatility ​ 99.0 % 95.0 % Term (in years) ​ 2.19 ​ 2.94 ​ Risk-free rate ​ 3.58 % 3.94 % ​ The following table provides a rollforward of the Public Warrants measured at fair value per Public Warrant using Level 1 inputs and Private Placement Warrants measured at fair value per Private Placement Warrant using Level 2 inputs: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Public Warrants ​ Private Placement Warrants ​ Level 1 Fair Value Level 2 Fair Value December 31, 2023 ​ $ 0.19 ​ $ 0.28 Change in fair value ​ $ 0.01 ​ $ 0.06 March 31, 2024 ​ $ 0.20 ​ $ 0.34 Change in fair value ​ $ (0.03) ​ $ (0.05) June 30, 2024 ​ $ 0.17 ​ $ 0.29 Change in fair value ​ $ (0.06) ​ $ (0.13) September 30, 2024 ​ $ 0.11 ​ $ 0.16 ​ The following tables provides a reconciliation of the change in fair value for the Public Warrants and Private Placement Warrants for the three months ended September 30, 2024: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Change in ​ ​ Warrant Class Level Warrants June 30, 2024 Fair Value September 30, 2024 Public Warrants 1 13,182,501 ​ $ 2,241 ​ $ (791) ​ $ 1,450 Private Placement Warrants 2 6,150,802 ​ $ 1,784 ​ $ (800) ​ $ 984 Total 19,333,303 ​ $ 4,025 ​ $ (1,591) ​ $ 2,434 ​ The following tables provides a reconciliation of the change in fair value for the Public Warrants and Private Placement Warrants for the nine months ended September 30, 2024: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Nine Months Change in ​ ​ Warrant Class Level Warrants December 31, 2023 Fair Value September 30, 2024 Public Warrants 1 13,182,501 ​ $ 2,505 ​ $ (1,055) ​ $ 1,450 Private Placement Warrants 2 6,150,802 ​ $ 1,722 ​ $ (738) ​ $ 984 Total 19,333,303 ​ $ 4,227 ​ $ (1,793) ​ $ 2,434 ​

Warrant Liabilities

Warrant Liabilities	9 Months Ended
	Sep. 30, 2024
Warrant Liabilities.
Warrant Liabilities	Note 7 – Warrant Liabilities The table below provides a summary of the outstanding Public and Private Placement Warrants at: ​ ​ ​ ​ ​ ​ ​ September 30, 2024 December 31, 2023 Public Warrants ​ 13,182,501 ​ 13,182,501 Private Placement Warrants ​ 6,150,802 ​ 6,150,802 ​ 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. 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. The table below provides the fair value of warrant liabilities at: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, 2024 ​ December 31, 2023 Fair value of warrant liabilities ​ $ 2,434 ​ $ 4,227 ​ The table below provides the Company’s gain recognized in connection with changes in fair value of warrant liabilities: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Nine Months Ended September 30, ​ ​ 2024 ​ 2023 ​ Gain recognized associated with warrant liabilities ​ $ 1,793 ​ $ 3,480 ​ ​ There have been no changes to our Public or Private Placement Warrants, including redemption terms disclosed in our 2023 Form 10-K.

Stockholders' Equity

Stockholders' Equity	9 Months Ended
	Sep. 30, 2024
Stockholders' Equity
Stockholders' Equity	Note 8 – Stockholders’ Equity Common Stock Stock options exercised for common stock, shares of common stock repurchased under the stock repurchase program, shares of common stock issued under the ESPP, and shares of common stock issued upon vesting of RSUs for the three and nine months ended September 30, 2024 and 2023 are summarized in the table below: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended September 30, ​ Nine Months Ended September 30, ​ ​ 2024 2023 ​ 2024 2023 ​ Stock options exercised ​ 832,122 ​ 58,065 ​ 4,423,019 ​ 2,084,695 ​ Shares of common stock repurchased ​ — ​ — ​ (5,000,000) ​ — ​ Shares of common stock issued under the ESPP ​ — ​ — ​ 187,614 ​ 129,928 ​ Shares of common stock issued for vested RSUs ​ 160,842 ​ 32,442 ​ 1,012,058 ​ 195,590 ​ ​ The table below presents the cash received or paid associated with common stock related activities for the three and nine months ended September 30, 2024 and 2023: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended September 30, ​ ​ Nine Months Ended September 30, ​ 2024 ​ 2023 ​ 2024 2023 Cash received from stock options exercised $ 35 ​ $ 11 ​ $ 232 ​ $ 194 Cash received from shares of common stock issued under the ESPP ​ — ​ ​ — ​ ​ 238 ​ ​ 214 Cash paid for shares of common stock repurchased ​ — ​ ​ — ​ ​ (8,274) ​ ​ — ​ Stock Repurchase Program On January 23, 2024, the Company announced that its 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. The Company did no t purchase any shares in the three months ended September 30, 2024. The table below presents the number of shares repurchased and retired, the aggregate cost, and the average purchase price per share for the nine months ended September 30, 2024: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Shares ​ ​ Aggregate cost ​ Avg. Price Paid Per Share Repurchased and retired shares of common stock ​ ​ 5,000,000 ​ $ 8,355 ​ $ 1.64 ​

Stock Based Compensation

Stock Based Compensation	9 Months Ended
	Sep. 30, 2024
Stock Based Compensation
Stock Based Compensation	Note 9 – Stock-Based Compensation There have been no changes to our equity incentive plans, the ESPP, or our accounting methodology for stock-based compensation, as disclosed in our 2023 Form 10-K. The fair value of stock options and RSUs issued to employees and directors is recognized as compensation expense over the period of service that generally coincides with the vesting period of the award. The Company allocated compensation ratably across Operating Expenses based on Company personnel costs incurred. When calculating the amount of annual compensation expense, the Company has elected not to estimate forfeitures and instead accounts for forfeitures as they occur. For the three and nine months ended September 30, 2024 and 2023, the Company recognized compensation costs totaling: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended September 30, ​ Nine Months Ended September 30, ​ 2024 2023 ​ 2024 2023 Stock-based compensation costs related to RSUs ​ $ 1,499 ​ $ 1,248 ​ $ 4,107 ​ $ 2,839 Stock-based compensation costs related to stock options ​ 1,529 ​ 2,012 ​ 4,756 ​ 5,486 Stock-based compensation costs related to the ESPP ​ ​ 45 ​ ​ 42 ​ ​ 124 ​ ​ 122 Total stock-based compensation costs ​ $ 3,073 ​ $ 3,302 ​ $ 8,987 ​ $ 8,447 ​ The unrecognized future compensation costs as of September 30, 2024 and 2023 were $22,407 and $31,843 , respectively. The following table summarizes our award activity for RSUs and stock options for the three and nine months ended September 30, 2024: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ RSUs ​ Stock Options Balance at December 31, 2023 ​ 4,473,016 ​ 24,264,016 Granted ​ 3,159,872 ​ ​ 4,566,167 Vested or Exercised ​ (264,754) ​ ​ (2,360,316) Forfeited ​ (72,619) ​ ​ (842,395) Balance at March 31, 2024 ​ 7,295,515 ​ ​ 25,627,472 Granted ​ 2,162,222 ​ ​ 1,757,960 Vested or Exercised ​ (867,515) ​ ​ (1,230,581) Forfeited ​ (886,343) ​ ​ (1,873,843) Balance at June 30, 2024 ​ 7,703,879 ​ ​ 24,281,008 Granted ​ 562,463 ​ ​ — Vested or Exercised ​ (206,133) ​ ​ (832,122) Forfeited ​ (333,651) ​ ​ (1,406,329) Balance at September 30, 2024 ​ 7,726,558 ​ ​ 22,042,557 ​ ​ ​ Stock Options The fair value of each stock option grant during the nine months ended September 30, 2024 and 2023 was estimated on the grant date using the Black-Scholes option pricing model with the following weighted-average assumptions used: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Nine Months Ended September 30, ​ ​ 2024 2023 ​ Approximate risk ‑ free rate ​ 4.23 % ​ 4.17 % ​ Volatility ​ 48.10 % ​ 46.91 % ​ Average expected life (in years) ​ 6 ​ ​ 6 ​ ​ Dividend yield ​ — % ​ — % ​ Weighted ‑ average grant date fair value ​ $ 1.59 ​ $ 2.80 ​ ​ Estimated fair value of total stock options granted ​ $ 5,175 ​ $ 7,815 ​ ​ ​

Basic and Diluted Loss Per Shar

Basic and Diluted Loss Per Share	9 Months Ended
	Sep. 30, 2024
Basic and Diluted Loss Per Share
Basic and Diluted Loss Per Share	Note 10 – Basic and Diluted Loss Per Share Basic loss per share represents net loss attributable to common stock divided by the basic weighted average number of shares of common stock outstanding during the period. Diluted loss per share also includes the dilutive effect of additional potential shares of common stock issuable from stock-based awards determined using the treasury stock method. Diluted loss per share represents net earnings divided by diluted weighted average number of shares of common stock, which includes the average dilutive effect of all potentially dilutive securities that are outstanding during the period. The table below sets forth the basic and diluted loss per share calculation for the three and nine months ended September 30, 2024 and 2023. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended September 30, ​ Nine Months Ended September 30, ​ ​ 2024 ​ 2023 ​ 2024 ​ 2023 ​ Net loss attributable to common stockholders ​ $ (22,419) ​ $ (15,142) ​ $ (65,900) ​ $ (46,507) ​ Weighted average shares outstanding – basic and diluted ​ ​ 179,160,488 ​ ​ 178,388,926 ​ ​ 179,177,452 ​ ​ 177,800,915 ​ Basic and diluted loss per share ​ $ (0.13) ​ $ (0.08) ​ $ (0.37) ​ $ (0.26) ​ ​ Due to the net loss for the three and nine months ended September 30, 2024 and 2023 presented above, diluted loss per share was computed without consideration to 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 for the three and nine months ended September 30, 2024 and 2023. ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, ​ ​ ​ 2024 2023 ​ Warrants ​ 19,333,303 19,333,303 ​ 2014 Plan & 2021 Plan - Stock Options ​ 23,497,907 26,386,130 ​ 2021 Plan - RSUs ​ 6,764,178 3,192,511 ​ ESPP - Common Stock ​ 167,548 ​ 120,339 ​ Total potentially dilutive securities ​ 49,762,936 ​ 49,032,283 ​ ​

Leases

Leases	9 Months Ended
	Sep. 30, 2024
Leases
Leases	Note 11 – 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, is under a noncancelable operating lease with a maturity date in December 2029. In 2022, the Company amended this operating lease to incorporate a prior subleased space into the base lease and extend the term of the lease. In 2024, the Company amended this operating lease to lease additional space and further extend the term of the lease. 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, 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 at the adoption date of the lease accounting standard on January 1, 2022, 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. The Company has certain equipment leases classified as finance leases as of September 30, 2024. 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: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended September 30, Nine Months Ended September 30, ​ ​ 2024 ​ 2023 2024 ​ 2023 ​ Finance lease costs: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Amortization of right-of-use assets ​ $ 58 ​ $ 50 ​ $ 174 ​ $ 141 ​ Interest on lease liabilities ​ 11 ​ 13 ​ 37 ​ 38 ​ Operating lease costs ​ 302 ​ 290 ​ 883 ​ 870 ​ Total lease expense ​ $ 371 ​ $ 353 ​ $ 1,094 ​ $ 1,049 ​ ​ The components of cash flow information related to leases are as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended September 30, Nine Months Ended September 30, ​ ​ 2024 ​ 2023 2024 ​ 2023 ​ Operating outgoing cash flows – finance leases ​ $ 11 ​ $ 13 ​ $ 38 ​ $ 39 ​ Financing outgoing cash flows – finance leases ​ 95 ​ 79 ​ 281 ​ 220 ​ Operating outgoing cash flows – operating leases ​ 441 ​ 284 ​ 1,025 ​ 851 ​ Right-of-use assets obtained in exchange for new finance lease liabilities: ​ ​ — ​ ​ 124 ​ ​ — ​ ​ 213 ​ Right-of-use assets obtained in exchange for new operating lease liabilities: ​ ​ 148 ​ ​ — ​ ​ 148 ​ ​ — ​ ​ ​ ​ ​ ​ ​ ​ September 30, 2024 Finance lease ​ Weighted-average remaining lease term – finance leases (in years) 2.3 ​ Weighted-average discount rate – finance leases 6.6 % Operating lease ​ ​ Weighted-average remaining lease term – operating leases (in years) 8.5 ​ Weighted-average discount rate – operating leases 6.8 % ​ As of September 30, 2024, future minimum payments during the next five years and thereafter are as follows: ​ ​ ​ ​ ​ ​ ​ Fiscal year Finance Lease Operating Lease 2024 (remaining three months) ​ $ 106 ​ $ 296 2025 ​ ​ 310 ​ ​ 1,210 2026 ​ ​ 179 ​ ​ 1,248 2027 ​ ​ 85 ​ ​ 1,288 2028 ​ ​ 16 ​ ​ 1,329 2029 ​ ​ — ​ ​ 1,211 Thereafter ​ ​ — ​ ​ 4,031 Total ​ ​ 696 ​ ​ 10,613 Less present value discount ​ ​ (48) ​ ​ (2,454) Total lease liabilities ​ $ 648 ​ $ 8,159 ​

Related Party Transactions

Related Party Transactions	9 Months Ended
	Sep. 30, 2024
Related Party Transactions
Related Party Transactions	Note 12 – Related Party Transactions During the three and nine months ended September 30, 2024 , the Company recognized $0 and $5,410 of revenue related to the BMW JDA, respectively. During the three and nine months ended September 30, 2023, the Company recognized $3,657 and $10,128 of revenue related to the BMW JDA, respectively. For the year ended December 31, 2023, the Company recorded $828 of deferred revenue related to cash paid from BMW in advance of services provided. On September 30, 2024, Solid Power Operating, Inc. and BMW entered into Amendment No. 6 to Joint Development Agreement. Pursuant to the terms of Amendment No. 6, the Company and BMW agreed to (i) extend the term of the BMW JDA until the Company hits certain development milestones; provided that BMW will have termination rights in certain circumstances beginning on December 31, 2025, and (ii) revise certain deliverables and the timing to achieve various milestones and development targets and confirm cell performance requirements.

Income Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2024
Income Taxes
Income Taxes	Note 13 – Income Taxes The Company’s effective tax rate was ( 1.64% ) and ( 1.34% ) for the three and nine months ended September 30, 2024, respectively, as a result of withholding tax expense on revenue earned in a foreign jurisdiction. The Company’s effective tax rate was 0% for the three and nine months ended September 30, 2023, and the Company was in a full valuation allowance for the three and nine months ended September 30, 2024 and 2023. The Company's quarterly provision for income taxes is calculated by applying a projected annual effective tax rate, calculated separately for the United States and Republic of Korea, to ordinary pre-tax book income.

Contingencies

Contingencies	9 Months Ended
	Sep. 30, 2024
Contingencies
Contingencies	Note 14 – Contingencies In the normal course of business, the Company may be party to litigation from time to time. 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.

Subsequent Events

Subsequent Events	9 Months Ended
	Sep. 30, 2024
Subsequent Events
Subsequent Events	Note 15 – Subsequent Events On October 21, 2024, the Company entered into a series of transactions with a third-party engineering consulting firm which included (i) acquiring a 20% equity position in the consulting firm in exchange for $400 and (ii) the right to acquire additional equity. Upon the execution of these transactions, the Company modified a promissory note from the consulting firm, which had an outstanding balance in Other assets as of September 30, 2024 of $4,448 . ​

Significant Accounting Polici_2

Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2024
Significant Accounting Policies
Basis of Presentation and Principles of Consolidation	Basis of Presentation and Principles of Consolidation The accompanying unaudited condensed consolidated financial statements of the Company have been prepared on the basis of 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. Additionally, certain prior period amounts have been reclassified to conform to current period presentation in the accompanying unaudited condensed consolidated financial statements.
Recent Accounting Pronouncements	Recent Accounting Pronouncements Income Taxes In December 2023, the FASB issued ASU 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 disclosure impact of ASU 2023-09. Segment Reporting In November 2023, the FASB issued ASU 2023-07 Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures. Among other new disclosure requirements, ASU 2023-07 requires companies to disclose significant segment expenses that are regularly provided to the chief operating decision maker, or CODM. ASU 2023-07 will be effective for annual periods beginning on January 1, 2024 and interim periods beginning on January 1, 2025. ASU 2023-07 must be applied retrospectively to all prior periods presented in the financial statements. The Company is currently evaluating the provisions and impact this ASU will have when adopted for the year ended December 31, 2024 and anticipates that it may result in additional required disclosures in the Company’s consolidated financial statements.

Property, Plant and Equipment (

Property, Plant and Equipment (Tables)	9 Months Ended
	Sep. 30, 2024
Property, Plant and Equipment
Schedule of property and equipment	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, 2024 December 31, 2023 ​ Production equipment ​ $ 40,328 ​ $ 36,086 ​ Laboratory equipment ​ ​ 11,524 ​ ​ 9,910 ​ Leasehold improvements ​ 70,793 ​ 59,109 ​ Furniture and computer equipment ​ 4,046 ​ 3,915 ​ Construction in progress ​ 8,585 ​ 13,650 ​ Total cost ​ 135,276 ​ 122,670 ​ Accumulated depreciation ​ (35,489) ​ (23,514) ​ Net property and equipment ​ $ 99,787 ​ $ 99,156 ​
Schedule of depreciation and amortization expense	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended September 30, ​ Nine Months Ended September 30, ​ ​ 2024 2023 ​ 2024 2023 ​ Depreciation expense ​ $ 4,014 ​ $ 2,896 ​ $ 11,980 ​ $ 7,794 ​
Schedule of construction in progress	​ ​ ​ ​ ​ ​ ​ ​ Construction in progress ​ September 30, 2024 ​ December 31, 2023 ​ SP1 - Capital projects ​ $ 4,722 ​ $ 2,298 ​ SP2 - Increased scale electrolyte production ​ ​ 3,863 ​ ​ 11,352 ​ Total ​ $ 8,585 ​ $ 13,650 ​ ​

Intangible Assets (Tables)

Intangible Assets (Tables)	9 Months Ended
	Sep. 30, 2024
Intangible Assets
Schedule of intangible assets	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, 2024 December 31, 2023 ​ ​ ​ Gross Carrying ​ Accumulated ​ Gross Carrying ​ Accumulated ​ ​ Amount Amortization Amount Amortization ​ Intangible assets: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Licenses ​ $ 149 ​ $ (67) ​ $ 149 ​ $ (61) ​ Patents ​ ​ 135 ​ ​ (10) ​ ​ 92 ​ ​ (5) ​ Patents pending ​ 1,708 ​ — ​ 1,444 ​ — ​ Trademarks ​ ​ 13 ​ ​ — ​ ​ 13 ​ ​ — ​ Trademarks pending ​ 25 ​ — ​ 18 ​ — ​ Total amortized intangible assets ​ $ 2,030 ​ $ (77) ​ $ 1,716 ​ $ (66) ​ ​
Schedule of amortization expense for intangible assets	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended September 30, ​ Nine Months Ended September 30, ​ 2024 2023 ​ 2024 2023 Amortization expense ​ $ 4 ​ $ 3 ​ $ 11 ​ $ 11 ​ ​

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2024
Fair Value Measurements
Schedule of financial assets and liabilities measured and recorded at fair value on a recurring basis	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, 2024 ​ Level 1 Level 2 Level 3 Total Assets ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Commercial Paper ​ $ 44,464 ​ $ — ​ $ — ​ $ 44,464 Corporate Bonds ​ $ 216,075 ​ $ — ​ $ — ​ $ 216,075 Government Bonds ​ $ 32,618 ​ $ — ​ $ — ​ $ 32,618 U.S. Treasuries $ 16,946 ​ $ — ​ $ — $ 16,946 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Liabilities ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Public Warrants ​ $ 1,450 ​ $ — ​ $ — ​ $ 1,450 Private Placement Warrants ​ $ — ​ $ 984 ​ $ — ​ $ 984 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2023 ​ Level 1 Level 2 Level 3 Total Assets ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Commercial Paper ​ $ 84,909 ​ $ — ​ $ — ​ $ 84,909 Corporate Bonds ​ $ 239,473 ​ $ — ​ $ — ​ $ 239,473 Government Bonds ​ $ 56,689 ​ $ — ​ $ — ​ $ 56,689 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Liabilities ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Public Warrants ​ $ 2,505 ​ $ — ​ $ — ​ $ 2,505 Private Placement Warrants ​ $ — ​ $ 1,722 ​ $ — ​ $ 1,722
Schedule of Level 2 inputs used in the recurring valuation of the Private Placement Warrants	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, 2024 December 31, 2023 Exercise price ​ $ 11.50 ​ $ 11.50 ​ Stock price ​ $ 1.35 ​ $ 1.45 ​ Volatility ​ 99.0 % 95.0 % Term (in years) ​ 2.19 ​ 2.94 ​ Risk-free rate ​ 3.58 % 3.94 %
Schedule of reconciliation of warrants measured at fair value	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Public Warrants ​ Private Placement Warrants ​ Level 1 Fair Value Level 2 Fair Value December 31, 2023 ​ $ 0.19 ​ $ 0.28 Change in fair value ​ $ 0.01 ​ $ 0.06 March 31, 2024 ​ $ 0.20 ​ $ 0.34 Change in fair value ​ $ (0.03) ​ $ (0.05) June 30, 2024 ​ $ 0.17 ​ $ 0.29 Change in fair value ​ $ (0.06) ​ $ (0.13) September 30, 2024 ​ $ 0.11 ​ $ 0.16
Schedule of fair value of warrant liabilities	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Change in ​ ​ Warrant Class Level Warrants June 30, 2024 Fair Value September 30, 2024 Public Warrants 1 13,182,501 ​ $ 2,241 ​ $ (791) ​ $ 1,450 Private Placement Warrants 2 6,150,802 ​ $ 1,784 ​ $ (800) ​ $ 984 Total 19,333,303 ​ $ 4,025 ​ $ (1,591) ​ $ 2,434 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Nine Months Change in ​ ​ Warrant Class Level Warrants December 31, 2023 Fair Value September 30, 2024 Public Warrants 1 13,182,501 ​ $ 2,505 ​ $ (1,055) ​ $ 1,450 Private Placement Warrants 2 6,150,802 ​ $ 1,722 ​ $ (738) ​ $ 984 Total 19,333,303 ​ $ 4,227 ​ $ (1,793) ​ $ 2,434 ​

Warrant Liabilities (Tables)

Warrant Liabilities (Tables)	9 Months Ended
	Sep. 30, 2024
Warrant Liabilities.
Summary of the outstanding Public and Private Placement Warrants	​ ​ ​ ​ ​ ​ ​ September 30, 2024 December 31, 2023 Public Warrants ​ 13,182,501 ​ 13,182,501 Private Placement Warrants ​ 6,150,802 ​ 6,150,802
Schedule of fair value of warrant liabilities	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, 2024 ​ December 31, 2023 Fair value of warrant liabilities ​ $ 2,434 ​ $ 4,227
Schedule of gain from changes in fair value of Warrant Liabilities	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Nine Months Ended September 30, ​ ​ 2024 ​ 2023 ​ Gain recognized associated with warrant liabilities ​ $ 1,793 ​ $ 3,480 ​

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	9 Months Ended
	Sep. 30, 2024
Stockholders' Equity
Schedule of stock options exercised for common stock	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended September 30, ​ Nine Months Ended September 30, ​ ​ 2024 2023 ​ 2024 2023 ​ Stock options exercised ​ 832,122 ​ 58,065 ​ 4,423,019 ​ 2,084,695 ​ Shares of common stock repurchased ​ — ​ — ​ (5,000,000) ​ — ​ Shares of common stock issued under the ESPP ​ — ​ — ​ 187,614 ​ 129,928 ​ Shares of common stock issued for vested RSUs ​ 160,842 ​ 32,442 ​ 1,012,058 ​ 195,590 ​
Schedule of cash received associated with common stock related activities	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended September 30, ​ ​ Nine Months Ended September 30, ​ 2024 ​ 2023 ​ 2024 2023 Cash received from stock options exercised $ 35 ​ $ 11 ​ $ 232 ​ $ 194 Cash received from shares of common stock issued under the ESPP ​ — ​ ​ — ​ ​ 238 ​ ​ 214 Cash paid for shares of common stock repurchased ​ — ​ ​ — ​ ​ (8,274) ​ ​ —
Schedule of number of shares repurchased and retired, aggregate cost, and the average purchase price	The Company did no t purchase any shares in the three months ended September 30, 2024. The table below presents the number of shares repurchased and retired, the aggregate cost, and the average purchase price per share for the nine months ended September 30, 2024: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Shares ​ ​ Aggregate cost ​ Avg. Price Paid Per Share Repurchased and retired shares of common stock ​ ​ 5,000,000 ​ $ 8,355 ​ $ 1.64 ​

Stock Based Compensation (Table

Stock Based Compensation (Tables)	9 Months Ended
	Sep. 30, 2024
Stock Based Compensation
Schedule of recognized & allocated compensation costs	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended September 30, ​ Nine Months Ended September 30, ​ 2024 2023 ​ 2024 2023 Stock-based compensation costs related to RSUs ​ $ 1,499 ​ $ 1,248 ​ $ 4,107 ​ $ 2,839 Stock-based compensation costs related to stock options ​ 1,529 ​ 2,012 ​ 4,756 ​ 5,486 Stock-based compensation costs related to the ESPP ​ ​ 45 ​ ​ 42 ​ ​ 124 ​ ​ 122 Total stock-based compensation costs ​ $ 3,073 ​ $ 3,302 ​ $ 8,987 ​ $ 8,447
Schedule of award activity for stock options and RSU's	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ RSUs ​ Stock Options Balance at December 31, 2023 ​ 4,473,016 ​ 24,264,016 Granted ​ 3,159,872 ​ ​ 4,566,167 Vested or Exercised ​ (264,754) ​ ​ (2,360,316) Forfeited ​ (72,619) ​ ​ (842,395) Balance at March 31, 2024 ​ 7,295,515 ​ ​ 25,627,472 Granted ​ 2,162,222 ​ ​ 1,757,960 Vested or Exercised ​ (867,515) ​ ​ (1,230,581) Forfeited ​ (886,343) ​ ​ (1,873,843) Balance at June 30, 2024 ​ 7,703,879 ​ ​ 24,281,008 Granted ​ 562,463 ​ ​ — Vested or Exercised ​ (206,133) ​ ​ (832,122) Forfeited ​ (333,651) ​ ​ (1,406,329) Balance at September 30, 2024 ​ 7,726,558 ​ ​ 22,042,557
Schedule of fair value of each option using the Black-Scholes option pricing model	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Nine Months Ended September 30, ​ ​ 2024 2023 ​ Approximate risk ‑ free rate ​ 4.23 % ​ 4.17 % ​ Volatility ​ 48.10 % ​ 46.91 % ​ Average expected life (in years) ​ 6 ​ ​ 6 ​ ​ Dividend yield ​ — % ​ — % ​ Weighted ‑ average grant date fair value ​ $ 1.59 ​ $ 2.80 ​ ​ Estimated fair value of total stock options granted ​ $ 5,175 ​ $ 7,815 ​ ​ ​

Basic and Diluted Loss Per Sh_2

Basic and Diluted Loss Per Share (Tables)	9 Months Ended
	Sep. 30, 2024
Basic and Diluted Loss Per Share
Schedule of reconciliation of basic weighted average common shares outstanding to diluted weighted average shares outstanding	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended September 30, ​ Nine Months Ended September 30, ​ ​ 2024 ​ 2023 ​ 2024 ​ 2023 ​ Net loss attributable to common stockholders ​ $ (22,419) ​ $ (15,142) ​ $ (65,900) ​ $ (46,507) ​ Weighted average shares outstanding – basic and diluted ​ ​ 179,160,488 ​ ​ 178,388,926 ​ ​ 179,177,452 ​ ​ 177,800,915 ​ Basic and diluted loss per share ​ $ (0.13) ​ $ (0.08) ​ $ (0.37) ​ $ (0.26) ​
Schedule of potentially dilutive securities excluded from the diluted earnings per share calculation	​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, ​ ​ ​ 2024 2023 ​ Warrants ​ 19,333,303 19,333,303 ​ 2014 Plan & 2021 Plan - Stock Options ​ 23,497,907 26,386,130 ​ 2021 Plan - RSUs ​ 6,764,178 3,192,511 ​ ESPP - Common Stock ​ 167,548 ​ 120,339 ​ Total potentially dilutive securities ​ 49,762,936 ​ 49,032,283 ​ ​

Leases (Tables)

Leases (Tables)	9 Months Ended
	Sep. 30, 2024
Leases
Schedule of components of lease related expense	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended September 30, Nine Months Ended September 30, ​ ​ 2024 ​ 2023 2024 ​ 2023 ​ Finance lease costs: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Amortization of right-of-use assets ​ $ 58 ​ $ 50 ​ $ 174 ​ $ 141 ​ Interest on lease liabilities ​ 11 ​ 13 ​ 37 ​ 38 ​ Operating lease costs ​ 302 ​ 290 ​ 883 ​ 870 ​ Total lease expense ​ $ 371 ​ $ 353 ​ $ 1,094 ​ $ 1,049 ​
Schedule of components of cash flow information related to leases	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended September 30, Nine Months Ended September 30, ​ ​ 2024 ​ 2023 2024 ​ 2023 ​ Operating outgoing cash flows – finance leases ​ $ 11 ​ $ 13 ​ $ 38 ​ $ 39 ​ Financing outgoing cash flows – finance leases ​ 95 ​ 79 ​ 281 ​ 220 ​ Operating outgoing cash flows – operating leases ​ 441 ​ 284 ​ 1,025 ​ 851 ​ Right-of-use assets obtained in exchange for new finance lease liabilities: ​ ​ — ​ ​ 124 ​ ​ — ​ ​ 213 ​ Right-of-use assets obtained in exchange for new operating lease liabilities: ​ ​ 148 ​ ​ — ​ ​ 148 ​ ​ — ​
Schedule of remaining weighted-average lease term and weighted-average discount rate	​ ​ ​ ​ ​ ​ September 30, 2024 Finance lease ​ Weighted-average remaining lease term – finance leases (in years) 2.3 ​ Weighted-average discount rate – finance leases 6.6 % Operating lease ​ ​ Weighted-average remaining lease term – operating leases (in years) 8.5 ​ Weighted-average discount rate – operating leases 6.8 %
Schedule of future minimum payments under finance lease	As of September 30, 2024, future minimum payments during the next five years and thereafter are as follows: ​ ​ ​ ​ ​ ​ ​ Fiscal year Finance Lease Operating Lease 2024 (remaining three months) ​ $ 106 ​ $ 296 2025 ​ ​ 310 ​ ​ 1,210 2026 ​ ​ 179 ​ ​ 1,248 2027 ​ ​ 85 ​ ​ 1,288 2028 ​ ​ 16 ​ ​ 1,329 2029 ​ ​ — ​ ​ 1,211 Thereafter ​ ​ — ​ ​ 4,031 Total ​ ​ 696 ​ ​ 10,613 Less present value discount ​ ​ (48) ​ ​ (2,454) Total lease liabilities ​ $ 648 ​ $ 8,159 ​
Schedule of future minimum payments under operating lease	As of September 30, 2024, future minimum payments during the next five years and thereafter are as follows: ​ ​ ​ ​ ​ ​ ​ Fiscal year Finance Lease Operating Lease 2024 (remaining three months) ​ $ 106 ​ $ 296 2025 ​ ​ 310 ​ ​ 1,210 2026 ​ ​ 179 ​ ​ 1,248 2027 ​ ​ 85 ​ ​ 1,288 2028 ​ ​ 16 ​ ​ 1,329 2029 ​ ​ — ​ ​ 1,211 Thereafter ​ ​ — ​ ​ 4,031 Total ​ ​ 696 ​ ​ 10,613 Less present value discount ​ ​ (48) ​ ​ (2,454) Total lease liabilities ​ $ 648 ​ $ 8,159 ​

Property, Plant and Equipment_2

Property, Plant and Equipment (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Property, Plant and Equipment
Total cost	$ 135,276	$ 122,670
Accumulated depreciation	(35,489)	(23,514)
Net property and equipment	99,787	99,156
Production equipment
Property, Plant and Equipment
Total cost	40,328	36,086
Laboratory equipment
Property, Plant and Equipment
Total cost	11,524	9,910
Leasehold improvements
Property, Plant and Equipment
Total cost	70,793	59,109
Furniture and computer equipment
Property, Plant and Equipment
Total cost	4,046	3,915
Construction in progress
Property, Plant and Equipment
Total cost	$ 8,585	$ 13,650

Property, Plant and Equipment -

Property, Plant and Equipment - Depreciation expense (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Property, Plant and Equipment
Depreciation expense			$ 11,991	$ 7,805
Property, Plant and Equipment
Property, Plant and Equipment
Depreciation expense	$ 4,014	$ 2,896	$ 11,980	$ 7,794

Property, Plant and Equipment_3

Property, Plant and Equipment - Construction in progress (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Property, Plant and Equipment
Construction in progress	$ 8,585	$ 13,650
Sp1 Capital Projects
Property, Plant and Equipment
Construction in progress	4,722	2,298
SP2 - Increased scale electrolyte production
Property, Plant and Equipment
Construction in progress	$ 3,863	$ 11,352

Intangible Assets (Details)

Intangible Assets (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023	Dec. 31, 2023
Intangible assets:
Gross Carrying Amount	$ 2,030		$ 2,030		$ 1,716
Accumulated Amortization	(77)		(77)		(66)
Amortization expense	$ 4	$ 3	$ 11	$ 11
Minimum
Intangible assets:
Useful lives of intangible assets	3 years		3 years
Maximum
Intangible assets:
Useful lives of intangible assets	20 years		20 years
Licenses
Intangible assets:
Gross Carrying Amount	$ 149		$ 149		149
Accumulated Amortization	(67)		(67)		(61)
Patents
Intangible assets:
Gross Carrying Amount	135		135		92
Accumulated Amortization	(10)		(10)		(5)
Patents pending
Intangible assets:
Gross Carrying Amount	1,708		1,708		1,444
Trademarks
Intangible assets:
Gross Carrying Amount	13		13		13
Trademarks pending
Intangible assets:
Gross Carrying Amount	$ 25		$ 25		$ 18

Fair Value Measurements - Asset

Fair Value Measurements - Assets and Liabilities Measured and Recorded at Fair Value on a Recurring Basis (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended		12 Months Ended
	Sep. 30, 2024	Sep. 30, 2024	Sep. 30, 2023	Dec. 31, 2023
Liabilities
Marketable securities and investments purchased		$ 174,040	$ 256,584
Recurring | Public Warrants
Liabilities
Liabilities	$ 1,450	1,450		$ 2,505
Recurring | Private Placement Warrants
Liabilities
Liabilities	984	984		1,722
Recurring | Level 1 | Public Warrants
Liabilities
Liabilities	1,450	1,450		2,505
Recurring | Level 2 | Private Placement Warrants
Liabilities
Liabilities	984	984		1,722
Recurring | Level 3
Liabilities
Transfers in or out of Level 3	0	0		0
Recurring | Commercial Paper
Assets
Assets	44,464	44,464		84,909
Recurring | Commercial Paper | Level 1
Assets
Assets	44,464	44,464		84,909
Recurring | Corporate Bonds
Assets
Assets	216,075	216,075		239,473
Recurring | Corporate Bonds | Level 1
Assets
Assets	216,075	216,075		239,473
Recurring | Government Bonds
Assets
Assets	32,618	32,618		56,689
Recurring | Government Bonds | Level 1
Assets
Assets	32,618	32,618		$ 56,689
Recurring | U.S. Treasuries
Assets
Assets	16,946	16,946
Recurring | U.S. Treasuries | Level 1
Assets
Assets	$ 16,946	$ 16,946

Fair Value Measurements - Measu

Fair Value Measurements - Measurement inputs (Details) - Recurring - Level 2 - Private Placement Warrants	Sep. 30, 2024 $ / shares Y	Dec. 31, 2023 $ / shares Y
Exercise Price
Fair Value Measurements
Measurement input, warrants	11.50	11.50
Stock Price
Fair Value Measurements
Measurement input, warrants	1.35	1.45
Volatility
Fair Value Measurements
Measurement input, warrants	0.990	0.950
Term
Fair Value Measurements
Measurement input, warrants | Y	2.19	2.94
Risk-free rate
Fair Value Measurements
Measurement input, warrants	0.0358	0.0394

Fair Value Measurements - Publi

Fair Value Measurements - Public Warrants measured at fair value using Level 1 directly observable inputs and Private Placement Warrants (Details) - Recurring - $ / shares	3 Months Ended
	Sep. 30, 2024	Jun. 30, 2024	Mar. 31, 2024
Public Warrants | Level 1
Reconciliation
Beginning balance, per share	$ 0.17	$ 0.20	$ 0.19
Change in fair value	(0.06)	(0.03)	0.01
Ending balance, per share	0.11	0.17	0.20
Private Placement Warrants | Level 2
Reconciliation
Beginning balance, per share	0.29	0.34	0.28
Change in fair value	(0.13)	(0.05)	0.06
Ending balance, per share	$ 0.16	$ 0.29	$ 0.34

Fair Value Measurements - Fair

Fair Value Measurements - Fair value for the Public Warrants and Private Placement Warrants (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2024	Sep. 30, 2024	Dec. 31, 2023
Reconciliation
Balance at the beginning		$ 4,227
Balance at the end	$ 2,434	$ 2,434
Recurring
Fair Value Measurements
Number of warrants outstanding	19,333,303	19,333,303
Reconciliation
Balance at the beginning	$ 4,025	$ 4,227
Change in fair value	(1,591)	(1,793)
Balance at the end	$ 2,434	$ 2,434
Public Warrants
Fair Value Measurements
Number of warrants outstanding	13,182,501	13,182,501	13,182,501
Public Warrants | Recurring | Level 1
Fair Value Measurements
Number of warrants outstanding	13,182,501	13,182,501
Reconciliation
Balance at the beginning	$ 2,241	$ 2,505
Change in fair value	(791)	(1,055)
Balance at the end	$ 1,450	$ 1,450
Private Placement Warrants
Fair Value Measurements
Number of warrants outstanding	6,150,802	6,150,802	6,150,802
Private Placement Warrants | Recurring | Level 2
Fair Value Measurements
Number of warrants outstanding	6,150,802	6,150,802
Reconciliation
Balance at the beginning	$ 1,784	$ 1,722
Change in fair value	(800)	(738)
Balance at the end	$ 984	$ 984

Warrant Liabilities (Details)

Warrant Liabilities (Details) - shares	Sep. 30, 2024	Dec. 31, 2023
Public Warrants
Warrant Liabilities
Number of warrants outstanding	13,182,501	13,182,501
Private Placement Warrants
Warrant Liabilities
Number of warrants outstanding	6,150,802	6,150,802

Warrant Liabilities - Additiona

Warrant Liabilities - Additional information (Details) - Warrants	Sep. 30, 2024 $ / shares shares
Warrant Liabilities
Class of warrant or right, number of securities called by each warrant or right | shares	1
Exercise price of warrants | $ / shares	$ 11.50

Warrant Liabilities - Fair valu

Warrant Liabilities - Fair value of warrant liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Warrant Liabilities.
Fair value of warrant liabilities	$ 2,434	$ 4,227

Warrant Liabilities - Changes i

Warrant Liabilities - Changes in fair value of warrant liabilities (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Warrant Liabilities.
Gain recognized associated with warrant liabilities	$ 1,591	$ 1,155	$ 1,793	$ 3,480

Stockholders' Equity - Stock op

Stockholders' Equity - Stock options exercised (Details) - shares	3 Months Ended		6 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Jun. 30, 2024	Jun. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Stockholders' Equity
Shares of common stock repurchased	0				(5,000,000)
Common Stock
Stockholders' Equity
Stock options exercised (in shares)	832,122	58,065	3,590,897	2,026,630	4,423,019	2,084,695
Shares of common stock repurchased			(5,000,000)		(5,000,000)
Shares of common stock issued under ESPP (in shares)			187,614	129,928	187,614	129,928
Shares issued upon vesting of RSUs (in shares)	160,842	32,442	851,216	163,148	1,012,058	195,590

Stockholders' Equity (Details)

Stockholders' Equity (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended	9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Jun. 30, 2024	Sep. 30, 2024	Sep. 30, 2023	Jan. 23, 2024
Stockholders' Equity
Cash received from options exercised	$ 35	$ 11		$ 232	$ 194
Cash received from shares of common stock issued under ESPP				238	$ 214
Cash paid for shares of common stock repurchased				$ (8,274)
Repurchased and retired shares of common stock (in shares)	0			5,000,000
Repurchased and retired shares of common stock (Aggregate cost)			$ 8,356	$ 8,355
Repurchased and retired shares of common stock (Avg. Price Paid Per Share)				$ 1.64
Amount of common stock repurchased, authorized						$ 50,000

Stock Based Compensation - Comp

Stock Based Compensation - Compensation costs (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Compensation cost
Equity-based compensation cost	$ 3,073	$ 3,302	$ 8,987	$ 8,447
Unrecognized compensation costs related to restricted stock units	22,407	31,843	22,407	31,843
Restricted stock units (RSUs)
Compensation cost
Equity-based compensation cost	1,499	1,248	4,107	2,839
Employee stock option
Compensation cost
Equity-based compensation cost	1,529	2,012	4,756	5,486
ESPP
Compensation cost
Equity-based compensation cost	$ 45	$ 42	$ 124	$ 122

Stock Based Compensation - Stoc

Stock Based Compensation - Stock options and Restricted stock units (Details) - shares	3 Months Ended			6 Months Ended	9 Months Ended
	Sep. 30, 2024	Jun. 30, 2024	Mar. 31, 2024	Jun. 30, 2024	Sep. 30, 2024
Restricted stock units (RSUs)
Restricted Stock Units.
Outstanding at beginning of period	7,703,879	7,295,515	4,473,016	4,473,016	4,473,016
Granted	562,463	2,162,222	3,159,872
Vested or Exercised	(206,133)	(867,515)	(264,754)
Forfeited	(333,651)	(886,343)	(72,619)
Outstanding at end of period	7,726,558	7,703,879	7,295,515	7,703,879	7,726,558
Employee stock option
Restricted Stock Units.
Vested or Exercised	(832,122)
Forfeited	(1,406,329)
Outstanding at end of period	22,042,557				22,042,557
Number of Shares
Outstanding at beginning of period	24,281,008	25,627,472	24,264,016	24,264,016	24,264,016
Granted		1,757,960	4,566,167
Vested or Exercised		(1,230,581)	(2,360,316)
Forfeited		(1,873,843)	(842,395)
Outstanding at end of period		24,281,008	25,627,472	24,281,008

Stock Based Compensation - Fair

Stock Based Compensation - Fair value of options granted (Details) - USD ($) $ / shares in Units, $ in Thousands	9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023
Stock Based Compensation
Approximate risk-free rate	4.23%	4.17%
Volatility	48.10%	46.91%
Average expected life (years)	6 years	6 years
Weighted-average grant date fair value	$ 1.59	$ 2.80
Estimated fair value of total stock options granted	$ 5,175	$ 7,815

Basic and Diluted Loss Per Sh_3

Basic and Diluted Loss Per Share - Schedule of reconciliation of basic weighted average common shares outstanding to diluted weighted average shares outstanding (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Basic and Diluted Loss Per Share
Net loss attributable to common stockholders	$ (22,419)	$ (15,142)	$ (65,900)	$ (46,507)
Weighted average shares outstanding - basic	179,160,488	178,388,926	179,177,452	177,800,915
Weighted average shares outstanding - diluted	179,160,488	178,388,926	179,177,452	177,800,915
Basic loss per share	$ (0.13)	$ (0.08)	$ (0.37)	$ (0.26)
Diluted loss per share	$ (0.13)	$ (0.08)	$ (0.37)	$ (0.26)

Basic and Diluted Loss Per Sh_4

Basic and Diluted Loss Per Share - Schedule of potentially dilutive securities excluded from the diluted loss per share calculation (Details) - shares	9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023
Earnings (Loss) Per Share
Total potentially dilutive securities	49,762,936	49,032,283
Warrants
Earnings (Loss) Per Share
Total potentially dilutive securities	19,333,303	19,333,303
2014 Plan & 2021 Plan - Stock Options
Earnings (Loss) Per Share
Total potentially dilutive securities	23,497,907	26,386,130
2021 Plan - RSUs
Earnings (Loss) Per Share
Total potentially dilutive securities	6,764,178	3,192,511
ESPP - Common Stock
Earnings (Loss) Per Share
Total potentially dilutive securities	167,548	120,339

Leases - Components of lease (D

Leases - Components of lease (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023	Sep. 01, 2021
Leases
Operating lease renewal term (in years)	5 years		5 years		5 years
Finance lease costs:
Amortization of right-of-use assets	$ 58	$ 50	$ 174	$ 141
Interest on lease liabilities	11	13	37	38
Operating lease costs	302	290	883	870
Total lease expense	$ 371	$ 353	$ 1,094	$ 1,049

Leases - Components of suppleme

Leases - Components of supplemental cash flow information (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Leases
Operating outgoing cash flows - finance leases	$ 11	$ 13	$ 38	$ 39
Financing outgoing cash flows - finance leases	95	79	281	220
Operating outgoing cash flows - operating leases	441	284	1,025	851
Right-of-use assets obtained in exchange for new finance lease liabilities:		$ 124		$ 213
Right-of-use assets obtained in exchange for new operating lease liabilities:	$ 148		$ 148

Leases - Lease term and discoun

Leases - Lease term and discount rate (Details)	Sep. 30, 2024
Leases
Weighted-average remaining lease term - finance lease (in years)	2 years 3 months 18 days
Weighted-average discount rate - finance lease	6.60%
Weighted-average remaining lease term - operating lease (in years)	8 years 6 months
Weighted-average discount rate - operating lease	6.80%

Leases - Schedule of future min

Leases - Schedule of future minimum payments (Details) $ in Thousands	Sep. 30, 2024 USD ($)
Finance Lease
2024 (remaining three months)	$ 106
2025	310
2026	179
2027	85
2028	16
Total	696
Less present value discount	(48)
Total lease liabilities	648
Operating Lease
2024 (remaining three months)	296
2025	1,210
2026	1,248
2027	1,288
2028	1,329
2029	1,211
Thereafter	4,031
Total	10,613
Less present value discount	(2,454)
Total lease liabilities	$ 8,159

Related Party Transactions (Det

Related Party Transactions (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023	Dec. 31, 2023
Related Party Transactions
Revenue from Related Parties	$ 4,651	$ 6,366	$ 15,679	$ 15,063
Deferred revenue	6,735		6,735		$ 1
Related Party | BMW
Related Party Transactions
Revenue from Related Parties	$ 0	$ 3,657	$ 5,410	$ 10,128
Deferred revenue					$ 828

Income Taxes (Details)

Income Taxes (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Income Taxes
Effective tax rate	1.64%	0%	1.34%	0%

Subsequent Events (Details)

Subsequent Events (Details) - USD ($) $ in Thousands	Oct. 21, 2024	Sep. 30, 2024
Subsequent Events
Notes receivable included in other assets		$ 4,448
Subsequent Event | Consulting firm
Subsequent Events
Ownership percentage, equity method	20%
Payments made to acquire equity method investments	$ 400