X0306 4 2022-06-24 1 0001844862 Solid Power, Inc. SLDP 0001899514 Volta Energy Technologies, LLC 28365 DAVIS PARKWAY, SUITE 202 WARRENVILLE IL 60555 0 0 1 0 Common Stock 2022-06-24 4 S 0 235853 6.2501 D 12015268 I By Volta SPV SPW, LLC Common Stock 2022-06-24 4 S 0 187402 6.2501 D 2246794 I By Volta Energy Storage Fund I, LP Common Stock 2022-06-24 4 S 0 33824 6.2501 D 3137745 I By Volta SPW Co-investment, LP The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $6.20 to $6.50, inclusive. The reporting person undertakes to provide to Solid Power, Inc., any security holder of Solid Power, Inc., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote 1. Securities owned directly by Volta SPV SPW, LLC ("Volta SPV"). The Reporting Person is the Managing member of Volta SPV. Securities owned by Volta Energy Storage Fund I, LP ("VESF"). The General Partner of VESF, Volta Energy Storage Fund I GP, LLC, is a wholly owned subsidiary of the Reporting Person. Securities owned by Volta SPW Co-investment, LP ("Volta Co-Invest"). The General Partner of Volta Co-invest, Volta Energy Storage Fund I GP, LLC, is a wholly owned subsidiary of the Reporting Person. /s/Mike Sodaro 2022-06-27