Toyota, Sumitomo Metal Develop New Cathode Material
By Reuters | 08 Oct, 2025

The development will advance the quest for solid-state EV batteries that are durable, safe and charge faster.

Toyota's logo is seen at an exhibition stall at the Bharat Mobility Global Expo organised by India's commerce ministry at Pragati Maidan in New Delhi, India, February 1, 2024. REUTERS/Anushree Fadnavis

Toyota and Sumitomo Metal Mining said on Wednesday they have made advances in the development of cathode materials for all-solid-state batteries for electric cars, and have agreed to work together to mass produce those materials.

Solid-state batteries hold the promise of improved safety, a longer lifespan and faster charging compared with conventional lithium-ion batteries that use flammable liquid electrolytes.

But mass adoption remains some way off due to constraints in raw material availability, intricate manufacturing processes and the resultant high costs.

Toyota, the world's biggest automaker by sales, is looking to launch EVs with all-solid-state batteries in 2027 or 2028.

The Japanese companies said their joint research since 2021 on cathode materials has focused on challenges such as cathode material degradation during repeated charging and discharging cycles, and they have now developed a "highly durable cathode material", using Sumitomo Metal's proprietary powder synthesis technology.

They will now work on improving the performance, quality, and safety of cathode materials, as well as reducing costs, their statement said, adding that they aim to achieve the world's first practical use of all-solid-state batteries in EVs.

Sumitomo Metal plans to start mass production of newly developed cathode materials as early as the financial year beginning April 2028, a company spokesperson said.

"We will prioritize supplying Toyota, then respond flexibly to market demand," the spokesperson said.

Toyota is also partnering with Idemitsu Kosan in solid-state batteries, with the oil refiner developing another key material, lithium sulphide.

(Reporting by Yuka Obayashi; Editing by Edwina Gibbs)