Toyota Seeks Battery That Stores More Energy than Gasoline

By · August 03, 2011

Today’s electric cars have batteries that offer about 100 miles of range on a charge. That, critics say, is the reason electric cars don’t compete with gas-powered vehicles and never will. Yet, those critics assume that technology stands still and overlook the potential of emerging battery technologies that could rapidly expand the range limitations of electric cars. You might laugh off claims of major battery breakthroughs coming from a garage tinkerer or start-up company—but none other than Toyota has recently been presenting technical papers about quantum leaps in energy-storage capacity.

The fact that Toyota researchers have been talking about next-generation battery technologies is significant for a few reasons. First, the company is better known for last-generation batteries for electric-drive cars—namely nickel-metal hydride that continues to power Toyota’s hybrids. Second, Toyota has been among the most reluctant to offer plug-in cars—only really jumping in with both feet with last year’s tie-up with Tesla. Even today, the company continues to emphasize that plug-in cars with small batteries are a better route than big-battery EVs. Yet, if we can believe the numbers displayed on one particular graph that Toyota researchers continue to show at technical conferences, then batteries won’t need to be very big to offer a driving range similar to gasoline vehicles.

The race to the Sakichi battery

The race to the so-called Sakichi battery

The above graph first surfaced in 2008, when Toyota established a research division to work on “revolutionary batteries.” At that time, the company talked about a “Sakichi battery,” named after Sakichi Toyoda, the inventor of Japan’s first power loom. He is sometimes referred to as the father of the Japanese industrial revolution. In 1925, Sakichi reportedly set out a (yet-to-be-claimed) prize of 1 million yen for the invention of a storage battery that would produce more energy than gasoline. Toyota’s goal is to make the Sakichi battery very durable and very quick to charge.

Persistence of Vision

Three years after establishing the research division, Toyota continues to show the graph. In fact, it was shown by Hideki Iba, general manager of Toyota battery research, at Third EV and HEV Drive System Technology Expo in Tokyo on Jan.18-20 of this year. Then, on May 18, 2011, (relatively soon after the devastation earthquake), Toyota’s Takeshi Uchiyamada, executive vice president, appeared at First International Electric Vehicle Technology Conference 2011 in Yokohama, where the slide popped up again.

The graph reveals that Toyota is focused on moving beyond lithium to solid state and metal air batteries. What jumps out at me is the X axis for energy density: As soon as you cross the “limit of conventional batteries,” and move into solid state technology—replacing the electrolytic solution in lithium-ion batteries with a solid—the energy density per liter increases by a factor of 10. Metal air takes energy storage even further in the direction of a Sakichi battery.

Is it time to start imagining a 100 kWh battery fitting into the same space as today’s battery? Or at least a battery that could offer multiple hundreds of miles on a charge in an even smaller package than what you see in a car like the 2011 Nissan LEAF?

Maybe not quite yet. It could be another decade or more before we move into the Sakichi era. But today’s electric cars already provide what typical U.S drivers require—while delivering a brisk enjoyable ride. With Toyota and other companies breathing down the neck of a battery breakthrough—whenever it does happen—we could push the range of electric cars from today’s 100 miles to multiple hundreds of miles. I can’t wait to see that day, and to see if such a development would finally silence the loudest critics of electric cars.

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