Sec Form 4 Filing - LEUSCHEN DAVID M @ Solid Power, Inc. - 2023-01-25

FORM 4 Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940

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1. Name and Address of Reporting Person LEUSCHEN DAVID M 2. Issuer Name and Ticker or Trading Symbol Solid Power, Inc. [ SLDP] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director X __ 10% Owner _____ Officer (give title below) _____ Other (specify below) (Last) (First) (Middle) C/O RIVERSTONE HOLDINGS LLC, 712 FIFTH AVENUE, 36TH FLOOR 3. Date of Earliest Transaction (MM/DD/YY) 01/25/2023 (Street) NEW YORK, NY10019 4. If Amendment, Date Original Filed (MM/DD/YY) 6. Individual or Joint/Group Filing (Check Applicable Line) _____ Form filed by One Reporting Person __ X __ Form filed by More than One Reporting Person (City) (State) (Zip)

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned 1.Title of Security (Instr. 3) 2. Transaction Date (MM/DD/YY) 2A. Deemed Execution Date, if any (MM/DD/YY) 3. Transaction Code (Instr. 8) 4. Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5) 5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4) 6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4) Code V Amount (A) or (D) Price Common Stock, par value $0.0001 per share 01/26/2023 J( 1 ) 3,651,546 D 4,738,454 I( 2 )( 5 ) By Decarbonization Plus Acquisition Sponsor III LLC Common Stock, par value $0.0001 per share 6,798,303 I( 3 )( 5 ) By REL Batavia Partnership, LP Common Stock, par value $0.0001 per share 485,112 I( 4 )( 5 ) By Riverstone SP Partners, LLC

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned ( e.g. , puts, calls, warrants, options, convertible securities) 1. Title of Derivative Security (Instr. 3) 2. Conversion or Exercise Price of Derivative Security 3. Transaction Date (MM/DD/YY) 3A. Deemed Execution Date, if any (MM/DD/YY) 4. Transaction Code (Instr. 8) 5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4, and 5) 6. Date Exercisable and Expiration Date (MM/DD/YY) 7. Title and Amount of Underlying Securities (Instr. 3 and 4) 8. Price of Derivative Security (Instr. 5) 9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4) 10. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 4) 11. Nature of Indirect Beneficial Ownership (Instr. 4) Code V (A) (D) Date Exercisable Expiration Date Title Amount or Number of Shares Warrants (right to buy) $ 11.5 01/25/2023 S 89,866 03/26/2022 12/08/2026 Common Stock, par value $0.0001 per share 89,866 $ 0.66( 6 ) 7,277,487 I See Footnotes( 2 )( 5 ) Warrants (right to buy) $ 11.5 01/26/2023 S 20,528 03/26/2022 12/08/2026 Common Stock, par value $0.0001 per share 20,528 $ 0.67( 7 ) 7,256,959 I See Footnotes( 2 )( 5 )

Reporting Owners Reporting Owner Name / Address Relationships Director 10% Owner Officer Other LEUSCHEN DAVID M C/O RIVERSTONE HOLDINGS LLC 712 FIFTH AVENUE, 36TH FLOOR NEW YORK, NY10019 X LAPEYRE PIERRE F JR C/O RIVERSTONE HOLDINGS LLC 712 FIFTH AVENUE, 36TH FLOOR NEW YORK, NY10019 X Signatures David M. Leuschen By: /s/ Peter Haskopoulos, Title: Attorney-in-Fact 01/26/2023 Signature of Reporting Person Date Pierre F. Lapeyre, Jr. By: /s/ Peter Haskopoulos, Title: Attorney-in-Fact 01/26/2023 Signature of Reporting Person Date

Explanation of Responses:

( 1 )On January 26, 2023, Decarbonization Plus Acquisition Sponsor III LLC ("DCRC Sponsor") distributed 3,651,546 shares of common stock, par value $0.0001 ("Common Stock"), of Solid Power, Inc. (the "Issuer") to its members pro rata. ( 2 )DCRC Sponsor is the record holder of these securities. David M. Leuschen and Pierre F. Lapeyre, Jr. are the managing directors of Riverstone Holdings LLC, which controls DCRC Sponsor. ( 3 )REL Batavia Partnership, LP is the record holder of these securities. David M. Leuschen and Pierre F. Lapeyre, Jr. are the sole members of the ultimate general partner of REL Batavia Partnership, LP. ( 4 )Riverstone SP Partners, LLC is the record holder of these securities. David M. Leuschen and Pierre F. Lapeyre, Jr. are the managing directors of Riverstone Holdings LLC, which is the managing member of Riverstone SP Partners, LLC. ( 5 )Each of Mr. Leuschen and Mr. Lapeyre may be deemed to have or share beneficial ownership of the securities held directly by DCRC Sponsor, REL Batavia Partnership, LP and Riverstone SP Partners, LLC. Each such person disclaims any such beneficial ownership of such securities except to the extent of their pecuniary interest therein, and this report shall not be deemed an admission that the reporting person is the beneficial owner of the securities for purposes of Section 16 or for any other purpose. ( 6 )The price reported in Column 8 of Table II is a weighted average price. The warrants were sold in multiple transactions at prices ranging from $0.65 to $0.75, inclusive. The reporting persons will provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, information regarding the number of warrants sold at each price within the range. ( 7 )The price reported in Column 8 of Table II is a weighted average price. The warrants were sold in multiple transactions at prices ranging from $0.65 to $0.67, inclusive. The reporting persons will provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, information regarding the number of warrants sold at each price within the range.

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.

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