Introduction

Abstract

Lithium air rechargeable batteries are now attracting growing as possible power sources for electric vehicles (EVs), because the battery system has a potential to develop a high energy density battery comparable with an internal conversion engine. A prototype rechargeable lithium air battery was proposed by Abraham and Jang in 1996 and Bruce and coworkers reported a successful result for the reversibility of the lithium air batteries using a conventional nonaqueous electrolyte and a catalyst in 2006. After that, many reports have been presented on the cell performance, stability of the electrolyte, and the electrode reaction mechanism. However, at present, no technology basis exists to superior the high optimistic energy density. Moreover, capacities for high power density and extended deep cycling required for the EV application have not shown. In this chapter, the realistic specific energy density of the rechargeable lithium air batteries is first presented. We emphasized on the comparison with that of the conventional rechargeable batteries, which presented the conversion yield of the ratio of the energy density of the practical cell and the calculated one. As the chemistry of the lithium air batteries has not been established, the brief history of the lithium air battery research was introduced. On the last part of the chapter, the key issues for realizing the high energy and power density lithium air batteries were discussed, including the comparison of nonaqueous and aqueous lithium air systems.