Sumitomo Metal Mining Co., Ltd. (OTC:SMMYY) and Toyota Motor Corporation (NYSE:TM) have signed a joint development agreement to move toward mass production of cathode materials for all-solid-state batteries destined for battery electric vehicles.Announced on Oct. 8, 2025, the collaboration advances work based in Tokyo and Toyota City to industrialize next-generation cells with higher output, longer life, and faster charge times.All-solid-state batteries use a solid electrolyte in place of liquid solutions, ...