Development of a lithium-ion battery pack system for EV

Abstract The lithium-ion battery has been commercialized in recent years mainly for use in small electric products. We have been researching energy sources for EV use that offer high levels of specific energy, specific power, cycle life and reliability. Among the many types of secondary batteries studied, a lithium-ion battery pack system with a cell control mechanism has been developed and evaluated for possible application to EVs. Experimental results show that it provides 100 Wh/kg of specific energy, almost three times as much as conventional lead-acid batteries, nearly 300 W/kg of specific power, 1.5 times more than other batteries, and a cycle life greater than several hundred. This system thus shows the most promising features as a potential energy source for EVs.