Worldwide race to make better batteries

Safety and cost remain top concerns, however. Lithium-ion batteries using cobalt chemistry, popularly used in laptop computers and cellphones, have in the past shown a propensity to overheat, resulting in a few laptops going up in flames.

That must not happen in a car, all agree. So while the search goes on for a powerful but stable and reliable battery chemistry, automakers are developing sophisticated battery management systems to monitor lithium cells for signs of impending failure. GM announced last week it will make its own computer-monitored pack to hold the LG Chem cells.

“There’s many layers of safety built into the Volt, that includes all the way down to the cell level,” Kruse says.

Cost is critical
Kruse won’t say whether the $10,000 price tag for the batteries floating around the media is correct. If so, the 16 kilowatt-hours (kWh) worth of energy in the GM battery pack would put the price at $625 per kwh of capacity. But the cost of the Chevy Volt battery should drop sharply once production ramps up, several experts say.

“Right now the price [for lithium PHEV batteries] is beyond what is required for a sustainable business,” says Ann Marie Sastry, a University of Michigan battery materials expert. “But automotive companies are going to take the risks and assume that [government] policies will help out.”

General Motors has talked about a $40,000 price tag for the Volt. That may be too costly for most Americans. The Obama administration has talked about a $7,500 tax break for PHEV buyers.

Still others say that the cost of new battery power for PHEVs may drop faster and already be lower than what has been widely reported at perhaps $500 per kilowatt-hour or even less, says Suba Arunkumar, analyst for market researcher Frost & Sullivan.

“I do expect the price will come down to perhaps as low as $200 per kilowatt-hour when mass production begins in 2010 and 2011,” she says.

With steady progress on all four fronts of lithium-ion cells – cost, safety, durability, and performance – Matthew Keyser, a battery researcher at the National Renewable Energy Laboratory in Golden, Colo., says attention is flowing to riskier, longer-term battery research of the sort “more likely to one-day produce a kind of Holy Grail battery.”

All batteries degrade with time. Right now, the Volt’s new battery is expected to last five to eight years. But with a typical car’s lifetime now about 17 years, automakers want a “life of the car” battery. With proper research funding, that goal is achievable, Mr. Keyser and Sadoway agree. The next generation of battery materials – perhaps vanadium oxide or nickelates – will lower costs by increasing capacity, they say.

“What we’ve done is to create a situation with a lot of people who smell big money and they’re working very hard,” says John Goodenough, the University of Texas at Austin professor who invented the lithium-ion battery. “I’m optimistic that in a few years, they’re going to lick the problem.”

[Editors note: The original version of this article misstated which regions of the world hold large deposits of lithium. China and South America sit on two of the largest caches.]

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