October 17, 2025: Sumitomo Metal Mining is teaming up with the Toyota Motor Corporation to mass produce cathode material for all-solid-state batteries.

The companies said on October 8 they have signed a joint development agreement for the project in support of production of battery electric vehicles (BEVs).

Toyota said it is aiming for a market launch of BEVs with all-solid-state batteries in 2027-2028.

The partners said they have been jointly conducting research into cathode materials since around 2021, focusing on challenges such as degradation during repeated charging and discharging cycles.

Sumitomo’s proprietary powder synthesis technology has enabled the companies to develop what they said is a “highly durable cathode material” suitable for all-solid-state batteries.

Work is now under way to further improve the performance, quality and safety of the technology, while ensuring cost-effective mass production methods, the partners said.

This March, Toyota declined to comment on reports that it was set to postpone construction of a lithium ion battery factory in Japan because of sluggish global demand for EVs.

Meanwhile, the Sumitomo conglomerate has also been developing its redox flow battery tech.
Sumitomo Electric Industries’ said this year it had been selected to support a pioneering grid-scale power stabilization system under construction in Japan.