Improved Electric Vehicle Performance with Pulsed Power Capacitors 931010

Recent technology developments have yielded double layer capacitor (DLC) products which store energy in the polarized liquid layer which forms when a potential exists between two electrodes immersed in electrolyte. Today's commercial DLC products are small, battery-like devices, generally using powdered carbon materials, which provide power during temporary failures of a primary power source.

Maxwell Laboratories, Inc., a manufacturer of high energy density film capacitors, is working with the Idaho National Engineering Laboratory and Auburn University to develop energy storage, capacitor products based upon double layer technology which uses electrode materials consisting of carbon and metal fibers in a sintered matrix configuration. Maxwell's ultimate goal is to mass produce an energy storage capacitor which will improve performance of an electric vehicle (EV) to the level of current internal combustion engines (ICE). In California, the push for all electric automobiles is primarily driven by tough new air-quality regulations which mandate that two percent of a manufacturer's cars sold in California, in 1998, must have zero tailpipe emissions. An automotive capacitor, powered by and working with the batteries in an EV, is a pulsed power source for pulling away from a light, merging into traffic, passing and emergency maneuvers. Put simply, the battery is used for cruising and the Auburn double layer capacitor for acceleration.

A DLC technology review, a listing of today's commercial DLC products and a research and technology update along with the latest test results for an automotive DLC based on sintered carbon-metal fiber materials are included in this paper.