Toyota Unveils Solid-State Battery Design for EVs

The biggest problems facing EVs like the Tesla Model S and the Nissan Leaf almost all come down to the batteries. Whether we’re talking about range anxiety, cost, charge time, or charging station availability across the US, we’re ultimately discussing battery chemistry, weight, and recharge times. Now, Toyota is apparently hoping to leapfrog its competitors and introduce a solid state lithium-ion battery.

According to the Japanese newspaper Chunichi Shimbun (via Reuters), Toyota wants to bring solid-state electrolyte batteries to market by 2022, with a charge time measured in minutes. The difference between a conventional lithium-ion battery and a solid-state version is the electrolyte composition between the cathode and the anode. Conventional lithium-ion batteries use a liquid electrolyte, but require relatively large spacers between each cell (20-30 micron separators per cell). By comparison, a solid-state lithium-ion battery requires just 3-4 microns for separators.

While you can’t apply that scaling to the entire battery, it’s been estimated solid state batteries could hold up to twice the charge of their liquid electrolyte counterparts. They’d also weigh less, be more durable, and wouldn’t be prone to catching fire in the same way lithium-ion batteries are, because they wouldn’t be using an electrolyte solution that contains flammable materials.

solid-state-battery-size

Image by Clean Technica

The Breakthrough Problem

Whenever a company announces a breakthrough, of any sort, it’s worth asking “Wow, if this new alternative is so amazing, why haven’t we been using it already?” The problem with solid-state lithium-ion batteries, at least to date, has been the poor conductance of the solid electrolyte. As the American Chemical Society details:

The problem is that most solids that conduct ions do so only sparingly, especially near room temperature, which is key for portable electronics. And an improvement in one property often comes at the expense of another. For example, modifying a solid to boost its ionic conductivity via chemical treatment or other means could make it more difficult to process, less stable electrochemically, or more expensive.

Toyota has been working on this puzzle since 2014, but has yet to announce any specifics of its battery chemistry design. And even if solid-state electrodes can be brought to market, there are other factors that could make them problematic to deploy. “There’s a pretty long distance between the lab bench and manufacturing,” CLSA auto analyst Christopher Richter told Reuters. “2022 is ages away, and a lot can change in the meantime.”

Battery technology needs to scale well, be relatively easy to duplicate as new manufacturing facilities are brought online, and offer some kind of cost or weight savings to be attractive to consumers. Well-heeled buyers might not mind paying more for a battery technology that offers 2-3x more range at the top of the market. Most auto manufacturers are focused on building BEVs and PHEVs that are less expensive, not more.

Solid-state lithium-ion technology has real promise, but it’s an open question whether Toyota can hit its 2022 release date. After all, it’s not the first time the company has made this claim. The Clean Technica link in the image caption above is to a 2013 story, in which Toyota reported it would have solid-state electrolytes on the market by 2020. Four years later, the company has only bumped its projected date back two years, which does reflect some progress, but this is clearly a moving target. Meanwhile, other companies, like BMW, are also investing in their own solid-state designs.

Now read: How Self-Driving Cars Work

Let’s block ads! (Why?)

ExtremeTechExtreme – ExtremeTech