Monday, April 4, 2011

Building Better Batteries for Electric Cars

Today’s electric car batteries no longer resemble Volta’s container, but they work on the same basic principles. And two centuries of gradual improvements in the overall chemistry, design and materials have led to the lithium-based battery that relies on a lithium ion to shuttle back and forth from the anode and cathode. Simply put, the lithium-ion battery offers a higher energy density than other previous battery systems, according to Venkat Srinivasan, manager of the Battery for Automotive Transportation Technologies Program, an Energy Department-supported program managed by Lawrence Berkeley National Laboratory at the University of California, Berkeley. Compared with the nickel-metal hydride battery used in the Toyota Prius, for example, a lithium-ion battery of the same weight and volume would increase energy density two to three times, said Dr. Srinivasan. More>