Toyota’s Solid-State Battery Lifespan Disappoints, Face Still More Challenges

They could be a major improvement over current batteries… if Toyota can get them to work.

byStephen Edelstein|
Toyota News photo

Toyota hopes to make up lost ground in the electric-car race with solid-state batteries, a technology that offers promise but that no automaker has adapted for production cars yet. And it seems Toyota still has a long way to go before it can become the first automaker to pull that off.

Toyota wants to get the solid-state batteries into production by the mid-2020s, but first, it has to solve some technical problems, reports Reuters. Solid-state batteries replace the liquid electrolyte used in today's lithium-ion battery cells with a solid material, which is supposed to improve performance and improve safety since, unlike the liquid electrolyte, the proposed solid material isn't flammable.

"We are scrambling to finish developing this technology, but a few issues still remain as we try to mass produce this," Takeshi Uchiyamada, Toyota chairman and the engineer who led the development of the first Prius hybrid, said in an interview with Reuters at the 2017 Tokyo Motor Show.

Battery life is the biggest of those issues, Uchiyamada said. Toyota has not found a way to make the batteries last long enough, although Uchiyamada did not specify the gap between what the company views as a reasonable lifespan and the current limits of the solid-state batteries. He did note that customers would not buy an electric car if the battery pack needed to be replaced after three years.

But Toyota still believes solid-state batteries hold great promise. The key is energy density, the amount of electricity that can be contained in a given volume. Solid-state batteries are supposed to provide greater energy density than conventional lithium-ion batteries, allowing automakers to build smaller, lighter battery packs without sacrificing range.

Yet solid-state batteries are still a largely unproven technology, and they certainly won't be a success in the automotive market with a limited lifespan. If Toyota can perfect the technology, it may leapfrog its competitors. Japan's largest automaker has been reticent to develop battery-electric cars, but has shown more interest recently as interest in hydrogen fuel-cell cars has lagged.

Toyota plans to continue developing fuel cells and increase production of hydrogen-powered cars tenfold over the next few years. But the company has faced numerous issues, including the slow rollout of hydrogen infrastructure, and current high production costs.