HEV(hybrid electric vehicle) batteries require higher current output than the batteries for general consumer use. A maximum output requirement is generally 100 A -150A. With our accumulated technologies, we have developed a nickel-metal hydride (Ni-MH) battery (D-size model: HR-DP) which meets the requirement of higher output. We announced our new battery at the 33 rd Tokyo Motor Show 1999. With the use of a lower resistance collector, battery has been improved which enabled us to lower the internal resistance. We have succeeded in assuring a current output 2.5 times as much as that of the consumer-use D-size battery. The optimization of the positive electrode has also improved charging characteristics at a high temperature and the improvement of the hydrogen absorbing alloy has improved cycle life. The ISG (Integrated Starter Generator) requires higher current than the HEV use, where a maximum requirement is from 300A to 500A. To meet with these high current requirements, we are currently under the development of M-size battery (model: HR-MP). In this paper, we discuss various improvements of the characteristics of the Ni-MH battery (HR-DP) for the HEV use, with more emphasis on output improvement, high temperature charging efficiency and prolonged cycle life. Some aspects of the Ni-MH battery (HR-MP) for the ISG use are also discussed.
展开▼
