New batteries and their impact on electric vehicles

The builder of an on-the-road electric vehicle (EV) has no problem in selecting a battery today because he has little choice. For small vehicles he must use a lead-acid golf car battery, while for a larger vehicle he may choose the heavier but more durable industrial-type lead-acid battery. This situation is changing rapidly. The technical literature is filled with recent papers recounting advances in one battery type or another. Each new battery offers a different combination of energy density (which defines the range capability of the vehicle), power density (which relates to the acceleration capability), cycle life, and cost (the battery economic parameters). To an EV manufacturer, this flood of data raises two questions: (1) how do I evaluate the various candidates for my job and (2) when can I expect a new battery to be ready for my vehicle. This paper suggests answers to these questions. 6 figures, 3 tables.