3M leads charge for EV battery

ST. PAUL, MN -- 3M Corp. gets a charge out of lithium polymer batteries (LPB) and the company says it expects drivers of future electric vehicles will as well.

With a $27.4 million grant from the United States Advanced Battery Consortium (USABC) 3M will, along with its partners Hydro-Quebec (a major Canadian utility) and Argonne National Laboratories, will continue to develop LPBs. The announcement was made here during a technology showcase for media at the company's headquarters. The grant is an extension of an initial $32.9 million research prize awarded in 1993.

The LPB uses cells made from a flexible, multi-layered film laminate 100 microns (.004 in.) thick. Its five layers include a current-collecting metal foil, cathode, electrolyte, lithium foil anode and insulator. The solid-state design, 3M says, is tough and can be wound and formed into almost any shape. The film's sandwich construction is so thin that it would take eight replications to equal the thickness of a credit card.

The company estimates that an LBP for an average-size car will require several miles of the film. When the funded program is complete near the turn of the century, 3M anticipates the new battery will offer a range of between 150 and 300 miles for an electric vehicle, compared with the 60 to 100 miles offered by current lead-acid technology.

3M expects LPBs will ultimately be able to produce 200 watt-hrs./kg, nearly six times more than the 35 watt-hrs./kg delivered by today's batteries.

During the next phase of development, several cells will be connected to form a battery pack for an electric or electric-hybrid vehicle. The goal, says 3M, is to create a power source by the end of the decade that would give an EV performance that equals a conventional gasoline-powered car.

"This is probably the end of the road for batteries," says Doug Kuller, business development specialist for 3M's new products division, adding that the next lightest element that could be used to power a vehicle is hydrogen, and that would likely be used in a fuel cell rather than a battery.

He says the LPB, which does not require water, won't be as sensitive to colder temperatures as current EV batteries since they will need to be warmed to 140[degrees]F to 212[degrees]F (60[degrees]C to 100[degrees]C) anyway.

"The engineering task of increasing reliability and integrating still has to be done," says Mr. Kuller.

In addition to the battery news, 3M announced that the new General Motors Corp. minivan and Ford Motor Co.'s new F-150 pickup would be equipped with its Filtrete cabin air filters, and that Saturn Corp. has approved the use of its Thinsulate acoustical insulation in its sedan.

The Chevrolet Venture, Pontiac TranSport and Oldsmobile Silhouette models are the first U.S. minivans to offer cabin-filtration systems. The Filtrete 1000 filter used is designed to catch particles measuring 0.3 micron and larger, but odors from the outside of the vehicle still will be noticeable. To trap both particles and odors, GM could have used 3M's new 5000 filter, a pleated Filtrete filter combined with a solid "cake" carbon filter that neutralizes smelly stuff. Ford's restyled F-150 pickup also has cabin filtration using a 3M 1000 series particulate filter.

Saturn sedans will have 3M's Thinsulate acoustical insulation beneath the door panels. Saturn is the first to specify the material, first used as lightweight thermal insulation in the garment industry. It has been re-engineered to bolster its sound-absorbing characteristics.