Toyota Won’t Share Solid-State Batteries With Tech Partner Mazda

"We are cooperating with Mazda on a dedicated EV architecture, but we are keeping in-house the research on solid-state batteries," Kiyotaka Ise, Toyota's chief safety technology officer," said at this week's Tokyo Motor Show. Ise did not say when the first cars from the Toyota-Mazda partnership will appear, but did say the jointly-developed electric car platform will be able to accommodate both solid-state batteries and conventional lithium-ion batteries.

Solid-state batteries replace the liquid electrolytes with a solid material. Among other benefits, that's supposed to increase energy density, allowing the batteries to store more electricity in a given volume. In a separate interview in Tokyo, Toyota executive vice president Didier Leroy called the technology a "game changer."

The first Toyota electric cars aren't expected to appear until sometime in the next decade. In the meantime, Toyota will continue to concentrate on hydrogen fuel-cell cars and hybrids, which the automaker has always preferred over battery-electric cars.

Even without Toyota's solid-state batteries, Mazda will likely benefit from the partnership. As a much smaller automaker, Mazda lacks the resources to undertake massive R&D projects like, say, the development of an all-new electric car platform. But it will probably need electric cars to meet stricter emissions standards. Countries like Germany and France are considering outright bans on sales of new gasoline and diesel cars, and Mazda needs to prepare for that future.