Car and Driver
August 23, 2017

Toyota teases solid-state battery breakthrough; Elon Musk skeptical.

Toyota Prius

For all the consistency and persistence that Toyota has applied to its Prius and hybrid technology, the automaker’s stance on electric cars has been a little harder to understand. After years of resisting any urge to create a rival for mass-produced electric cars such as the Nissan Leaf—or even the BMW i3 or the Tesla Model S—Toyota has a mass-market electric vehicle back on the development path. And according to a report, it may use solid-state batteries.

Solid-state technology, in simple terms, replaces the liquid or gel electrolyte between electrodes with a solid, crystalline electrolyte. While that could potentially give it several big (theoretical) performance advantages, like higher energy density, faster recharging, and a longer cycle life, none of these are likely to be realized in the form that is most developed at this point—using metallic lithium as the electrode material.

The Japanese paper that originally reported Toyota’s plan, Chunichi Shimbun, didn’t cite sources—although Reuters quoted a spokeswoman for Toyota in Japan who confirmed that the company aims to commercialize full solid-state batteries by the early 2020s. Furthermore, the same spokeswoman told a Forbes contributor based in Japan that among new-generation batteries, “solid-state batteries are considered closest to the level of practical application required to equip vehicles for volume production.”

In the United States, Toyota’s official response is a little more cagey. “We are working on research and development, including the production engineering of all-solid batteries to commercialize them by the early 2020s,” confirmed Craig Taguchi, Toyota’s senior manager for U.S. product communications. “However, we can’t comment on specific product plans.”

Some in the industry have been skeptical about the claim that the automaker could be that close to mass production of a multicell solid-state battery pack. Critics include Tesla CEO Elon Musk, who was asked about the development during Tesla’s quarterly financial results conference call earlier this month. Musk responded with exasperation about the possibility of a solid-state-battery breakthrough. “Tesla is the biggest buyer of lithium-ion batteries on earth,” he boasted. “You know who people come to first when they’ve got a lithium-ion battery? Us, because we’re their biggest customer.”

This is where we should remind everyone that Toyota—a Tesla shareholder and sometime partner since 2010—sold out its interest in Musk’s company in June, making the former partners rivals and, should Toyota bring a radical electric vehicle to market, direct competitors.

JB Straubel, Tesla’s chief technical officer, responded that the company is cautiously optimistic about the technology and said it has tested a number of single-cell solid-state prototypes. “But we don’t see anything that changes our strategy,” he said.

Controversy over Commercial Viability

Solid-state batteries for automotive technology are still in the research stage with no timeline for commercialization,” said Menahem Anderman, the president of Total Battery Consulting and a longtime expert on the EV-battery market. Anderman underscored that solid-state batteries aren’t likely to cycle as well as the lithium-ion chemistries currently used and that they can be expected to be more expensive and more difficult to produce.

Anderman confirmed what Musk said, commenting that the technology “is not on the development path really, still research.”

So where does this leave Toyota’s alleged solid-state technology? We’re not sure; but if the company can pull it off, much of the battery industry—including Tesla—will be genuinely disrupted. Much as Toyota accomplished with the Prius.

Written by Bengt Halvorso