Premier electric vehicle battery maker Hitachi and its Hitachi Vehicle Energy unit used this week's Automotive Engineering Exposition 2009 in Yokohama, Japan, to release information on their latest and most efficient Lithium-ion (Li-ion) battery for automotive applications. This new fourth-generation design has a power density of 4,500 watts per kilogram, which is 1.7 times as much energy as the cells that it currently supplies to the industry and a significant leap beyond the 3,000 W/kg output of the gen III battery that it will start mass producing sometime in 2010.
According to Hitachi, this latest battery -- which it will start field testing in the fall -- is even lighter and more compact than the upcoming gen III unit. While withholding several proprietary details, the firm says its additional capacity comes as the result of advances in structural design, particularly in the areas of reduced electrode thickness and enhanced power collection methods. The battery also uses a new manganese cathode that significantly lowers internal resistance. Hitachi, which has already delivered over 600,000 Li-ion battery packs to various automotive and industrial clients, now plans to expand its involvement into the area of controllers and system solutions.