Abstract
Further progress in automotive technologies is likely to contribute to solving several environmental and energy preservation issues. The automotive industry has quickly responded to this expectation and performed extensive research and development programs for the future. Amongst those technologies under investigation, high expectations are raised for the Electric Vehicle (EV), Hybrid Electric Vehicle (HEV) and the Fuel Cell Electric Vehicle (FCEV). EV is more flexible as the primary en- ergy source while it features high energy efficiency and no exhaust emissions except for the emissions from power generation system, as well as contributions to reduced CO2 emission levels. Since the battery technology as an energy storage system is the heart of the EV, several issues and the entropy concept of battery development will be discussed.