X0306 4 2023-01-25 1 0001844862 Solid Power, Inc. SLDP 0001222726 LEUSCHEN DAVID M C/O RIVERSTONE HOLDINGS LLC 712 FIFTH AVENUE, 36TH FLOOR NEW YORK NY 10019 0 0 1 0 0001232151 LAPEYRE PIERRE F JR C/O RIVERSTONE HOLDINGS LLC 712 FIFTH AVENUE, 36TH FLOOR NEW YORK NY 10019 0 0 1 0 Common Stock, par value $0.0001 per share 2023-01-26 4 J 0 3651546 D 4738454 I By Decarbonization Plus Acquisition Sponsor III LLC Common Stock, par value $0.0001 per share 6798303 I By REL Batavia Partnership, LP Common Stock, par value $0.0001 per share 485112 I By Riverstone SP Partners, LLC Warrants (right to buy) 11.50 2023-01-25 4 S 0 89866 0.66 D 2022-03-26 2026-12-08 Common Stock, par value $0.0001 per share 89866 7277487 I See Footnotes Warrants (right to buy) 11.50 2023-01-26 4 S 0 20528 0.67 D 2022-03-26 2026-12-08 Common Stock, par value $0.0001 per share 20528 7256959 I See Footnotes 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. 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. 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. 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. 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. 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. 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. David M. Leuschen By: /s/ Peter Haskopoulos, Title: Attorney-in-Fact 2023-01-26 Pierre F. Lapeyre, Jr. By: /s/ Peter Haskopoulos, Title: Attorney-in-Fact 2023-01-26