GM to Build Its Own Batteries

Continued from page 1

The ride: General Motors will make its own battery packs for the Chevrolet Volt (shown here) and other electric vehicles. Credit: John F. Martin for General Motors

Ann Marie Sastry, a professor of materials science and engineering at the University of Michigan, says that the battery program was started in 2007 because "we faced a serious shortage of engineers in the industry. There weren't enough people well versed in electrification to flip the vehicle portfolio to electric vehicles. We'll need hundreds and hundreds of engineers."

Although GM will build its own battery packs, it will continue to buy battery cells from outside suppliers, since developing new electrode chemistries and manufacturing the cells themselves require expensive equipment, says Kruse. Experts have long predicted that GM would turn to LG Chem, a large, experienced battery company, rather than to startup A123 Systems. Although LG Chem will supply the first-generation battery packs, GM is already developing its second- and third-generation packs, which could use cells from other manufacturers, including A123, with which GM has a development contract.

One of the biggest priorities at the company's new laboratory will be assessing and extending the lifetime of batteries. Lithium-ion batteries (commonly used in cell phones and laptops) lose their ability to store energy in just a couple of years. The Volt battery has been engineered to last eight to ten years, so that it doesn't have to be replaced during the lifetime of a vehicle, but to achieve this, the company had to oversize the battery pack to compensate for a loss in storage capacity. The pack stores 16 kilowatt-hours of electricity, but only 8 of these will be used for the car's 40-mile range. In the future, the company hopes to use far fewer batteries to achieve the same range.