Mitsubishi to build lithium ion car batteries by 2010

With the number of hybrid cars on the rise there is an increasing need to make a more compact and fuel efficient battery than the nickel metal hydride batteries presently used. Exploring the potential in the plug-in hybrid car battery, Mitsubishi Heavy Industries plans to start mass production of Lithium Ion batteries (more compact and fuel efficient) for hybrid cars in 2010. The rechargeable batteries are to be sold to automakers for use in electric and gas-electric hybrid vehicles. The technology for manufacturing the Lithium Ion batteries may still be expensive but the other safety hazard of overheating still remains a sore point. Mitsubishi Heavy may have to rely on their expertise gained from developing large Lithium Ion batteries for household power units with Kyushu Electric Power.

Other Japanese Companies trying to gain a foothold in this line are Nissan Motor and electronics group NEC (in a joint venture), Sanyo Electric (already supplies nickel metal hydride batteries to Honda Motor and Ford Motor), Hitachi, GS Yuasa and Murata Manufacturing. Companies outside of Japan include Johnson Controls and Cobasys, a venture of Chevron and Energy Conversion Devices.
Source