Advanced Car Batteries
Electrifying vehicles could slash petroleum use and help clean the air (if electric power shifts to low-carbon fuels like wind or nuclear). But it’s going to take better batteries.
In a lithium-air battery, oxygen flows through a porous carbon cathode and combines with lithium ions from a lithium-metal anode in the presence of an electrolyte, producing an electric charge. The reaction is aided by a catalyst, such as manganese oxide, to improve capacity.
Lithium-ion batteries, common in laptops, are favored for next-generation plug-in hybrids and electric vehicles. They’re more powerful than other auto batteries, but they’re expensive and still don’t go far on a charge; the Chevy Volt, a plug-in hybrid coming next year, can run about 40 miles on batteries alone. Ideally, electric cars will get closer to 400 miles on a charge. While improvements are possible, lithium-ion’s potential is limited.
One alternative, lithium-air, promises 10 times the performance of lithium-ion batteries and could deliver about the same amount of energy, pound for pound, as gasoline. A lithium-air battery pulls oxygen from the air for its charge, so the device can be smaller and more lightweight. A handful of labs are working on the technology, but scientists think that without a breakthrough they could be a decade away from commercialization.
Via: WSJ, Diagram Source: EDSRC.
