Development of a LiFePO4-based high power lithium secondary battery for HEVs applications

A LiFePO4-type lithium secondary battery cell of 8 Ah capacity with a high energy density and power density was developed for hybrid electric vehicle (HEV) applications by optimizing the key raw materials and process design. The 8 Ah class LiFePO(4)cell with an energy density of 77.2 Wh center dot kg(-1)exhibits a power density of 2818 W center dot kg(-1)at 50 % SOC (state of charge). The battery shows good cyclic capability with the capacity retention of 81.1 % after 1,870 cycles at 5C charge and 10C discharge rates. It is demonstrated that the cells have an excellent balance of high-power, high-energy, low temperature, and long-life performance for meeting the requirements of HEV.