X0609 4 2026-03-31 0 0001844862 Solid Power, Inc. SLDP 0001880162 Buettner-Garrett Joshua false C/O SOLID POWER, INC. 486 S PIERCE AVE., SUITE E LOUISVILLE CO 80027 0 1 0 0 Chief Technology Officer 0 Common Stock 2026-03-31 4 F 0 14284 2.82 D 1279925 D Common Stock 2026-04-01 4 A 0 183518 0 A 1463443 D Represents shares of the issuer's common stock withheld to satisfy the reporting person's tax obligation upon the vesting of restricted stock units. Each restricted stock unit represents a contingent right to receive one share of the underlying common stock of the Issuer. The restricted stock units will vest in 16 equal quarterly installments commencing on June 30, 2026, and thereafter at the end of each fiscal quarter of the Issuer, subject to the reporting person continuing to be a service provider (as defined in the Solid Power, Inc. 2021 Equity Incentive Plan) through the applicable vesting date. /s/ Kristen Gould, attorney-in-fact on behalf of Joshua Buettner-Garrett 2026-04-02