Traditional 2 volt cell above, with foam cell below.
Remember the lowly car battery? That greasy thing with corroding terminals, universally ignored until it runs out of juice?
It's being ignored no longer. With the advent of plug-in hybrids and electric cars like the Tesla Roadster and the Lightning GT, the battery is now taking center stage.
A new generation of batteries -– safer, cleaner and far more powerful -– is beginning to emerge, batteries that can meet the demanding requirements of cars propelled by electricity.
Firefly Energy, a spinoff from heavy equipment manufacturer Caterpillar, is breathing new life into lead-acid batteries, a technology that hasn't changed much since Thomas Edison used them to power electric cars in the 1890s.
Firefly has replaced the lead plates found inside conventional batteries with a lead-impregnated foam made from carbon graphite –- one of the few materials that can withstand the highly corrosive sulfuric acid inside batteries. The foam increases the surface area of lead inside the battery, delivering more power and slashing the recharge time, says Firefly CEO Ed Williams.
Equally important, Firefly's approach eliminates the crystals that can build up inside lead-acid batteries. Over time, those crystals reduce the amount of electricity a battery can hold, one of the major reasons electric and hybrid automakers have favored lithium-ion or nickel batteries, even though lead acid is less expensive.
"Our batteries will come back to their full capacity for years," says Williams.
In addition to electric and hybrid cars, Firefly is looking at snowmobiles and lawn mowers -- anything that sits for long periods without being used. Lack of use is really hard on lead-acid batteries, and shortens their life significantly because of the formation of those crystals.
Firefly is eying other markets as well, such as data centers, which use lead-acid batteries in backup power systems, and truck manufacturers, who pack large banks of batteries into the cabs of semis to provide power for drivers when they're not on the road.
Don Hillebrand, director of the Center for Transportation Research at Argonne National Laboratory, which evaluates plug-in hybrid vehicles and batteries for the Department of Energy, said Firefly's technology is very promising, a "potentially game-changing technology."
But Hillebrand believes that the ultimate medium for electric vehicles' batteries may well be lithium ion, the same material used today in batteries for laptop computers.
"Lithium is just in the right place on the periodic table," he says. Already, lithium-ion batteries are the power storage device of choice for the sleek and sexy electric Tesla Roadster, which is packed with 6,800 of them.
But lithium-ion batteries aren't exactly trouble-free.
"In their charged state, lithium-ion batteries are intrinsically unstable," says Bart Riley, the CTO of A123Systems, a Watertown, Massachusetts, company that is using nanotech research to create a new and safer version of lithium-ion batteries.
"If they get damaged, or there's a manufacturing defect, as was the case with the Sony batteries last year, there can be a spontaneous internal short, and you've got an explosion or fire," Riley says.
A123Systems has modified the chemical structure of lithium-ion batteries, substituting iron for the cobalt used today.
The result is a battery that can be recharged far more often, and is more stable chemically, and thus safer. The combination makes the company's batteries "particularly well-suited for plug-in hybrids," Riley says.
The batteries are in use in an aftermarket module that converts cars like the Toyota Prius into plug-in hybrids, and General Motors is evaluating them for its Chevrolet Volt plug-in hybrid.
A123Systems' batteries are already in use in a line of souped-up power tools from Black & Decker, which hold anywhere from two to three times the charge of existing handheld power tools.
Reno, Nevada-based startup Altairnano, meanwhile, is also using nanotechnology to build a new generation of lithium-ion batteries.
Made from tiny particles of titanium dioxide and other ceramic materials, the company's NanoSafe battery has up to 100 times more chargeable surface area inside than existing batteries. That means they can be recharged in minutes, and deliver three times the power of existing lithium-ion batteries, says Alan Gotcher, Altairnano's president.
The batteries are going into the ultra-sleek -– and ultra-pricey –- British electric sports car, the Lightning GT, as well as the American-made Phoenix Motorcars electric truck, which is due to start shipping later this year.
While Firefly, A123Systems and Altairnano are among the leading contenders to power the next generation of electric cars and plug-in hybrids, none of them yet has all the features they need for that market, according to Hillebrand. And there are wild cards, like the battery that isn't a battery from reclusive EEStor, a Kleiner Perkins Caufield & Byers-funded startup out of Cedar Park, Texas.
EEStor is using exotic materials such as barium titanate to build a ceramic supercapacitor capable of storing enough energy to power an electric car.
Richard Weir, the company's president, is tight-lipped about details, but says the device, which can be recharged in minutes, will weigh less than 100 pounds, and should begin shipping later this year.
With all these options, car makers are waiting and watching to see which technology will emerge as the leader, says Hillebrand.
The new batteries could replace the ones in cars now, but this probably won't happen for a generation or two -- maybe three to five years. Current cars don't ask much of a battery, which is partly why major battery manufacturers haven't done much new product development. High volumes of current lead-acid batteries mean manufacturing costs are much lower than new battery technologies, even if the new technology lasts two to three times longer.
"It's still a wide-open frontier," Hillebrand says. "Battery research is an exciting place to be right now."
Posts
