Toyota will debut solid-state batteries, one of the most significant technologies coming to electric vehicles, at the 2020 Tokyo Olympic Games.
"Mass-production will be later. At the 2020 Olympics it will probably be an e-Palette with Toyota’s solid-state battery in operation. I am advocating the use of solid-state batteries in e-Palette. For mass-production model you will have to wait a little while longer," he said.
Solid-state batteries address many of the issues with the lithium-ion batteries currently commonplace in phones, computers, and (of course) cars.
Rather than using a liquid electrolyte, solid-state batteries rely on a solid polymer metal electrolyte. That means there's nothing volatile or flammable inside the battery pack, improving their safety and heat-management properties.
That opens the door for batteries packing significantly more range into a smaller package – known as energy density. The potential for ultra-fast charging without significant battery degradation is also better with solid-state batteries.
The technology is "intrinsically much more stable under a variety of both normal and abnormal operating conditions" than current lithium-ion tech according to Professor Douglas MacFarlane, energy theme leader of the Australian Centre for Electromaterials Science.
"Lithium-ion batteries contain a flammable liquid electrolyte which doesn't go well once it is heated beyond about 150 degrees or so," MacFarlane told CarAdvice.
"The battery has got a tendency to overheat itself under certain kinds of maltreatment or damage, like a collision in a car would be an issue."
"And once the battery gets too hot, the whole thing just begins to go into a 'thermal runaway' we call it, which ultimately produces a fire or even a small explosion of the battery, which is pretty serious in a big battery pack."
In contrast, a Massachusetts Institute of Technology report on solid-state batteries says you could drive a nail through them, or smash them against the wall, and they'd be unlikely to catch fire.
Toyota has previously promised a mass-produced EV will solid-state batteries will debut in 2022.