A manganese type Lithium ion battery was developed for both PEV(pure EV) and HEV(hybrid EV) application by improving the weak points in conventional technology. A 90 Ah single cell was developed for PEV use, and it was applied to an integrated 8-cell module which has an energy density of 93 Wh/kg and 114 Wh/dm(3) and power density of 350 W/kg at depth of discharge (DOD) 85%. The Mn type Li ion cell for PEV use was modified to give it a high power density. The 48-cell module for HEV has the output power density of 1350 W/kg at DOD 50%. These batteries are already used in commercial vehicles and are proving to have excellent performance.