SES AI Corp

Rule 10b5-1 Trading Arrangements

On March 4, 2025, Jing Nealis (our Chief Financial Officer)terminated a Rule 10b5-1 plan that had been adopted on May 30, 2024 which provided for the sale of up to 870,000 shares of Class A common stock underlying vested stock options with an expiration date of February 10, 2031 (and which plan initially had a duration of the earlier of August 25, 2025 or the completion of all transactions thereunder).

On March 28, 2025, eachof Qichao Hu (our Founder, Chairman and Chief Executive Officer), Jing Nealis (our Chief Financial Officer), Hong Gan (our Chief Science Officer), Kyle Pilkington (our Chief Legal Officer), Kang Xu(our Chief Technology Officer”) and Gang “Daniel” Li (our Chief Manufacturing Officer, and collectively with Dr. Hu, Ms. Nealis, Dr. Gan, and Mr. Pilkington, the “Executive Officers”) entered into written stock selling plans in accordance with Rule 10b5-1 (the “Plans”)under the Exchange Act in

connection with the sale of shares of Class A common stock underlying RSUs granted to Dr. Hu, Ms. Nealis, Dr. Gan, Mr. Pilkington, Dr. Xu, and Mr. Li on March 28, 2025. The Plans provide for the sale of only such number of shares necessary to satisfy minimum statutory withholding tax obligations arising from the vesting of such equity awards (with the RSUs vesting subject to continued service in three equal installments on each anniversary of the grant date,), and, thus, the exact number of shares to be sold is unknown. Each Plan expires once all shares are sold to satisfy the applicable Executive Officer’s withholding tax obligations.