Abstract
In recent years worldwide energy usage and environmental issues have raised serious social concerns. In addition to this, because of the spike in world fuel prices, fuel-efficient and low-emission vehicles are attracting lots of attention and world vehicle manufacturers are concentrating a lot of effort on developing HVs.
Panasonic EV Energy Co., Ltd. (PEVE) began commercial production of Nickel Metal-hydride batteries for HV applications in 1997 and currently supply various Automakers. PEVE began mass production of its first generation prismatic Nickel Metal-hydride battery in 2000 and its second generation battery, which provided 30% more power and required less room, in 2003. In march 2005, PEVE have successfully developed and started production of a new prismatic nickel metal hydride battery that achieves a reduction in size about 10% and improvement in 40% cooling performance while maintaining the same capabilities and characteristics as the current model. These developments have been achieved by introducing (1) new prismatic shape (2) new case material, (3) new current collection system, and (4) new electrode materials.
To achieve required durability of the battery system, not only the battery durability itself, but also the battery monitoring and control during vehicle driving is very important. For this purpose, various battery behaviours like voltage and temperature during ordinary usage and abuse usage at the initial stage and at the end of the life are studied. These information are built into the battery management unit and it communicates with vehicle during driving and send signal to limit power.
To meet requirement of the HV applications, both of the battery development and its management system is highly important. This is achieved by the understanding of the battery chemistry, electric component and real vehicle usage through the market experiences. PEVE have sold over 800,000 battery packs for HV applications through above development and will be continuously contributed to the popularization of the HVs in the future.
Keywords:Hybrid Vehicle, Nickel Metal-hydride battery, Prismatic, Battery Management, PEVE