Toyota is one of the world's three largest carmakers, along with General Motors and Volkswagen Group.

Having placed its bets for the future of zero-emission transport on hydrogen fuel-cell vehicles, it's by far the most resistant of the three to the notion of battery-electric cars.

But a recent news story might possibly indicate a crack in the company's intransigence.

DON'T MISS: 2017 Toyota Prius Prime: first drive of new plug-in hybrid

It hinted that Toyota may now plan to offer an electric car beyond the low-range "city car" ghetto it's traditionally assigned to battery-only vehicles.

An article yesterday from global news service Reuters suggested that Toyota is warming to lithium-ion battery cells—and it explained why.

First, though, some context is needed.

2012 Toyota Prius Plug-In Hybrid, Catskill Mountains, NY, Oct 2012

2012 Toyota Prius Plug-In Hybrid, Catskill Mountains, NY, Oct 2012

Back in 2010, Toyota held a technical seminar for journalists at the Detroit Auto Show on its then-new third-generation Prius hybrid.

In a lengthy technical presentation by its managing officer Koei Saga, he revealed that the lithium cell that it planned to use in the battery of the 2010 Prius used a nickel-based chemistry.

That energy-dense lithium chemistry proved impossible for the company to produce economically, he said, so it fell back on the nickel-metal-hydride packs it had used for more than a decade.

ALSO SEE: Why The 2010 Toyota Prius Doesn't Have A Lithium-Ion Battery (Feb 2010)

Five hundred prototype Toyota Prius Plug-In Hybrid test vehicles used the nickel-based lithium cells, but when the production version launched in 2012, it had a different lithium cell chemistry altogether.

And it's only now, with the fourth-generation Toyota Prius launched in 2016, that Toyota is offering lithium-ion batteries for its signature advanced-technology hybrid vehicle.

They are provided by its traditional cell supplier, Panasonic, though engineers from the two companies have worked closely together on everything from cell chemistry to pack design, cooling, and electronics.

2017 Toyota Prius Prime Premium

2017 Toyota Prius Prime Premium

The Reuters article quotes Koji Toyoshima, the chief engineer for the latest Prius—and its Prius Prime plug-in hybrid version—discussing the safety challenges of lithium-ion chemistries.

"It's a tall order to develop a lithium-ion car battery which can perform reliably and safely for 10 years," he told Reuters, "or over hundreds of thousands of kilometers."

The article details Toyota's various activities in developing packs for the 2017 Prius Prime that meet its safety requirements and product needs.

CHECK OUT: Toyota Accelerates Switch To Lithium-Ion Batteries, Still Lags Others (May 2013)

Sophisticated control software monitors the temperature and operating characteristics of each cell in real time; better precision in cell manufacturing eliminates impurities than can short out an individual cell; and shrinking cell size for greater energy density and better battery packaging.

Those disciplines, frankly, sound like the same things battery engineers at other companies have been doing for a decade.

To date, meanwhile, Toyota's two generations of RAV4 EV electric crossover have used either nickel-metal-hydride packs (for the first generation) or Tesla batteries and motors (for the 2012-2014 compliance-car model).

2012 Toyota RAV4 EV, Newport Beach, California, July 2012

2012 Toyota RAV4 EV, Newport Beach, California, July 2012

But the money quote comes toward the end of the article: "Developing lithium-ion batteries for both hybrids and plug-ins will enable us to also produce all-electric cars in the future," Toyoshima told Reuters.

Not "could," not "would," but "will." It may be the first time we've seen a Toyota executive acknowledge that its technology not only could, but likely will, be used for future cars powered solely by batteries.

If that's a precise translation from the Japanese, it marks a significant turn in Toyota's attitudes.

[hat tip: Brian Henderson]


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