DuPont Co. has a new polyimide-based separator for lithium-ion batteries that is designed to improve the power and life of batteries for hybrid and electric cars.
The Wilmington, Del.-based company is also building a facility near Richmond, Va., to make the new Energain separators.
A separator is a film positioned between the two electrodes in every battery, functioning as a barrier that prevents the electrodes from touching, while letting lithium ions pass between them to allow the charge and discharge of the battery.
A hybrid car uses between 50 and 70 batteries. A plug-in hybrid car uses between 80 and 200 batteries, while fully electric cars such as those from Nissan Motor Co. Ltd. and General Motors Co. hitting the market later this year carry at least 150.
DuPont's new separator, made with the high-temperature, chemical-resistant polyimide and nanofiber, improves efficiency over existing batteries, boosting power 15- 30 percent and battery life by 20 percent, DuPont claims. Other separators already on the market use a mixture of other thermoplastics, including polypropylene and polyethylene.
Those improvements will allow automakers to either provide the same power with fewer batteries or increase power from the same number of batteries, said Mike Sanders, global director of DuPont's Energy Storage Solutions.
They can make more choices this way, he said in an Aug. 3 interview at the auto industry's Management Briefing Seminars in Traverse City.
DuPont has already invested $50 million during the past five years to develop Energain. It is undergoing testing at 20 different battery companies and 10 different original equipment manufacturers, Sanders said.
The separator is a natural expansion for polyimide in lithium-ion batteries. DuPont's Kapton polyimide film already is used elsewhere in the cell.
DuPont will also market Energain for use in liquid filtration applications in the biopharmaceutical, microelectronics, food and beverage industries.
DuPont has already made initial quantities in Wilmington and Seoul, South Korea. The Virginia plant will begin production in the first quarter of 2011, with initial capacity to supply up to 20 percent of current hybrid and electric vehicles.