How Toyota's 745-mile Solid-State Battery Got A Massive Boost From Idemitsu

But while Toyota isn’t exactly cranking out EVs as fast as it does hybrid Corollas, it has pioneered solid-state EV batteries. Toyota was the first automaker to throw serious money at the solid-state cause in 2012. Its partnership with the petroleum company Idemitsu has been instrumental to the project.

After many years of waiting, the time for solid-state batteries could finally be here.

What Toyota And Idemitsu Bring To The Table

Toyota and Idemitsu both have specialized research teams and other engineers and scientists.
Idemitsu is providing the raw materials that Toyota will use for its batteries.
Toyota has collaborated with other companies, including Idemitsu, but is retaining sole control over its battery project.

Both Toyota and Idemitsu bring generous funds and passels of scientists to the solid-state project. But in a more general sense, the two companies are a near-perfect match. Idemitsu is providing the raw materials for the batteries, and Toyota is producing the cars that they will eventually go in. Toyota already had several years of solid-state battery research before partnering with Idemitsu, which allows the two companies to skip several years of misdirected initial trials.

Idemitsu Is Providing Raw Materials And Refining Processes

A sample of solid-state battery electrolyte in a glass vial

Idemitsu is providing Toyota with sulfides, which are byproducts of petroleum refining. In other words, one company’s trash is another company’s treasure. Toyota will use the sulfides to make the electrolytes for its solid-state batteries. To be clear, it is not true that Toyota is filling its batteries with petroleum byproducts. Instead, the sulfides are the starting ingredients for the process that ultimately yields the batteries’ electrolytes.

Toyota Has Collaborated With Outside Companies To Develop Its Own Battery, But Will Manufacture It Alone

Toyota is apparently planning to completely control its battery production instead of contracting with outside manufacturers. This desire for total control may seem surprising given Toyota’s relatively halfhearted history with EVs. However, Toyota can better maintain its legendary reliability if it avoids any unnecessary tangles with outside suppliers.

But even though Toyota has not announced any plans to collaborate on battery production or completely contract it out, it is not attempting to develop its solid-state battery without outside help. In addition to its partnership with Idemitsu, Toyota shares over 1,000 patents with fellow Japanese company Panasonic.

Even the biggest car company on earth can’t make batteries alone. Toyota, the company that introduced Americans

Despite its public image as a manufacturer of unimaginative and reliable cars, Toyota has introduced multiple revolutionary technologies to the automotive industry.
Toyota introduced the driving public to hybrids, which no automaker had been able to successfully sell before.
Toyota was the first company to seriously research solid-state EV batteries.

Toyota tends to downplay its history of technological breakthroughs. After all, the latest technology may be exciting, but it also tends to be finicky and break down. However, Toyota has radically changed the auto industry multiple times. As early as the 1970s, Toyota introduced Americans to the then-radical concept of cars like the Camry, which were pleasant to drive but didn’t burn one gallon of fuel per mile. American automakers had sold small cars before then, but they tended to be punitively economical. (Indeed, American automakers still struggle to reconcile the concepts of “fun to drive” and “fuel economy”.)

Toyota was the first company to successfully sell cars with an electric motor going to the wheels, albeit with a conventional engine still under the hood. Of course, Toyota did not invent hybrid cars, no more than Tesla invented EVs. However, Toyota was the first company to successfully get them into people’s driveways.

It’s easy to forget how bonkers a hybrid car seemed in 1997. As evidenced by the many years of previous marketing failures, only Toyota could have convinced people that such a complicated car wouldn’t break down. Toyota bypassed the enthusiast community and aimed the first mass-market hybrid directly at commuters and other people who actively avoid popping the hood of their cars. The Prius was almost punitively unimaginative (aside from the novelty powertrain). It was also so successful that no hybrid can escape its shadow. Indeed, automakers often avoid the dreaded “H-word” when advertising hybrid pickups to avoid any association between trucks’ open-bed burliness and the Prius.

Indeed, Toyota’s successful Prius launch may have informed how it entered the then-nonexistent hydrogen market in 2014. As it did with the Prius, the company bypassed the “two doors, two seats, two inches of ride height” purism of car enthusiasts and put a hydrogen fuel system into an otherwise forgettable commuter sedan.

When Toyota first announced it would attempt to produce a solid-state EV battery in 2012, few people (if any) took the news seriously. After all, Toyota had only made a few half-hearted attempts towards EVs before then. But as Toyota got closer to a working prototype, companies throughout the auto industry rushed to develop their own. But for reasons known only to those who can read internal memos, Toyota’s battery development started faltering around this time. Things went from uncertain to unlikely at the 2020 Tokyo Olympics. Toyota had announced that it would have a demonstration battery on display. Despite getting a one-year homework extension when the pandemic delayed the Olympics to 2021, Toyota was absent without comment.

In 2025, the world got definitive proof that Toyota had squandered its lead. Mercedes installed its own solid-state battery into a car and actually drove it. This was the first time anyone had actually bolted a solid-state battery into a car and made it move, a previously insurmountable hurdle despite several billions of dollars of industry spending. Toyota still has the chance to be the first company to get a solid-state battery into production, but it is clear that it is falling behind in its own revolution.