Toyota, Idemitsu team for all-solid-state battery breakthrough by 2028

TOKYO – Toyota Motor Corp. is taking another step toward a breakthrough in solid-state batteries for electric cars with a new partnership to develop mass-production methods for the critical electrolyte, the automaker said in a statement.

The deal, announced Thursday, teams the world’s largest automaker with Japanese petrochemical giant Idemitsu Kosan to commercialize the advanced battery technology in the 2027-2028 time frame, paving the way for what they called “full-scale” mass production.

Successful development of all-solid-state batteries is seen as critical to unlocking the potential of full electric vehicles by enabling much longer ranges in smaller, lighter packages.

The batteries, which have a ceramic-like electrolyte instead of a liquid one, are much more energy-dense, faster charging and considered safer than today’s liquid-electrolyte lithium ion batteries. The batteries are seen as especially beneficial in sports cars and big SUVs.

The batteries are scheduled to arrive in time to help Toyota achieve its goal of selling 3.5 million EVs worldwide in 2030, including the Toyota and Lexus brands.

But it remains a challenge to manufacture solid-state batteries at scale while maintaining quality. Toyota is developing the advanced battery technology at its Teiho factory in Toyota City, where it previewed its efforts to journalists in September.

Toyota plans two versions of all-solid-state batteries. The first will arrive around 2027 to 2028. Toyota targets a range of more than 621 miles for that battery and predicts it will recharge to 80 percent state of charge from 10 percent in about 10 minutes.

The second solid-state battery will arrive at an unspecified date. Toyota has said it will have a range exceeding 745 miles.

Toyota and Idemitsu, in a joint statement, said they will work to develop mass production technology of solid electrolytes, improve productivity and establish a supply chain for all-solid-state batteries for battery-electric vehicles.

Idemitsu has been working on the fundamentals of solid-state batteries since 2001, while Toyota began its own R&D in 2006, the companies said.

The upcoming cooperation will focus on sulfide solid electrolytes. The companies said that  promising chemistry enables high energy capacity and high-power output. Sulfide solid electrolytes are also soft and sticky, making them well suited to mass production, they said.

The companies have established a task force with “dozens” of members to deliver the technology, through a three-phase road map that leads to commercialization in 2027-2028 and ends with a forward-looking study of manufacturing even more advanced solid-state batteries.

Idemitsu already has a small pilot plant making sulfide solid electrolytes and is building a large pilot factory as a test bed for commercialization in the next four to five years.

Idemitsu President Shunichi Kito said the company was considering eventual mass production of the solid electrolyte at its plant in Chiba prefecture just east of Tokyo. Investment levels haven’t been finalized, Idemitsu said.

Keiji Kaita, head of battery development at Toyota, said the automaker plans to set up its first line for manufacturing solid-state batteries around in the area around the company’s Toyota City global headquarters near Nagoya.

The companies said the batteries will be suitable for “global widespread use” and that Toyota ensures "market launch of BEVs with all-solid-state batteries in 2027-28.”

At Toyota’s recent tour of its Teiho plant development facility, the automaker showed how it overcame problems in stacking the layers of cathode-anode cells precisely and at high speeds.

Toyota engineers said they have cracked the code of solid-state battery materials. The next challenge, they say, is speeding up output while maintaining quality and safety.

— Naoto Okamura contributed to this report.