First, the good news: a top executive at SB LiMotive says it may be possible to design lithium batteries that can deliver a 300-mile daily range.
And now the bad news: the prototype batteries have an unsettling tendency to burst into flames.
And that, in a nutshell, is what occupies Joachim Fetzer these days. As executive vice president of SB LiMotive, it's Fetzer's job to deliver lithium ion batteries to customers--mission accomplished--and figure out how to improve their performance--a work in progress.
SB LiMotive is a 50-50 joint venture between Robert Bosch and Samsung, launched in 2008. The venture is based in South Korea and has contracts to supply batteries for eight automakers.
The company will supply the Fiat 500 EV and the BMW i3 electric car, among others.
Happily, global battery makers have figured out how to design cooling systems that prevent lithium ion batteries from overheating. But it gets tricky when researchers experiment with alternative chemistries that would allow them to store more energy in the battery.
During an interview at the Frankfurt auto show, Fetzer said two new battery types--lithium sulfur and lithium air--are especially promising. Lithium sulfur chemistry, which uses relatively light and inexpensive sulfur, is capable of high energy densities. In lithium air cells, positively charged ions flow to oxygen in porous carbon cathodes, which cuts weight and boosts energy density.
"I expect these things," Fetzer said. "There is good progress being made. The optimistic assumption is we'll see these batteries in the first half of the next decade."
A lithium sulfur battery might be able to store 400 to 500 watt hours per kilogram while a lithium air battery might store at least 1,000 watt hours per kilogram, Fetzer said.
By comparison, a conventional lithium ion battery typically stores a maximum of 150 watt hours per kilogram. That's enough, Fetzer noted, for automakers to design electric cars with a range of 100 miles or so.
(Source: Automotive News)