Toyota and Sumitomo Metal Mining said they have developed a durable cathode material for solid-state batteries, marking a step toward mass production of safer, longer-lasting electric vehicle batteries. The companies, which began joint research in 2021, will now focus on improving efficiency, cost, and large-scale manufacturability.
Using Sumitomo’s proprietary powder synthesis process, the new material resists degradation over repeated charge cycles, helping extend battery life. Toyota plans to debut solid-state EVs by 2027 or 2028, while Sumitomo aims to start mass production in fiscal 2028, first supplying Toyota.
Solid-state batteries are considered a breakthrough in EV technology, offering faster charging and enhanced safety compared to current lithium-ion systems. Yet high production costs and raw material limits remain barriers to widespread use.
Toyota is also collaborating with Idemitsu Kosan, which is developing lithium sulphide for battery electrolytes, reinforcing Japan’s lead in next-gen EV innovation.




