LiFePO4/C of high purity grade was successfully synthesized by microwave accelerated sol–gel synthesis and showed excellent electrochemical performance in terms of specific capacity and stability. This cathode material was characterized in battery configuration with a graphite counter electrode by USABC–DOE tests for power-assist hybrid electric vehicle. It yielded a non-conventional Ragone plot that represents complexity of battery functioning in power-assist HEV and shows that the pulse power capability and available energy of such a battery surpasses the DOE goal for such an application.