Toyota is not ready to compromise on nickel-metal hydride technology
Bipolar batteries achieve better performance by combining the anode and cathode terminals in the same current collector. Before, the anodes and cathodes had their own complexes.
The new arrangement not only saves space, but also provides a greater current of electricity.
On a large scale, the cost of manufacturing batteries is lower because they contain fewer components. But production is now limited. The bipolar batteries are manufactured by the group’s subsidiary Toyota Industries Corp, which currently only has enough capacity for 240,000 vehicles per year.
For conventional nickel-metal hydride batteries, by contrast, Toyota supplies about 1.6 million units annually, primarily from Primearth EV Energy Co. in Japan, as well as sources in China.
Okumura said it is a mistake to think that nickel-metal hydride batteries are old and that lithium-ion batteries are new. He said development of the two species began around the same time. But it so happened that nickel-metal hydride made it first on the market.
“The public has an image that nickel-metal hydride batteries are old, but in reality they are not,” Okumura said. “We started developing this new type of nickel-metal hydride battery because after 20 years of using it, there has been a track record.
“But the basic design has not changed significantly,” he said. “So we decided to take on the challenge of increasing production.”
Due to the strong current and output, new batteries are best suited for hybrid cars that require quick bursts of energy, as opposed to electric vehicles that need a large energy store.
Toyota places lithium-ion as the main EV battery. But Toyota believes the bipolar structure can also be applied to lithium-ion batteries, leading to potential improvements in these power packs.