Chapter 5 - Fluorine-doped tin oxide electrods for lithium batteries

Abstract

Lithium batteries are considered to be the best alternative for a portable power source because they provide high output power and have moderate lifetime. However, their capacity is limited by the electrode materials they contain. Hence, much effort has been made to improve the performance of the electrode materials. The control of crystallite size is a key factor in determining the specific capacity and the cycling efficiency of electrodes. The studies on alloy-based anode materials have also shown the effects of crystallite size on the dimensional stability and capacity retention of the electrode. To overcome some disadvantages of alloy-based anode materials, nanocrystalline materials have been intensively investigated. This chapter begins with a brief history of tin oxide as an anode electrode for lithium batteries. It discusses the doping approach for improving tin oxide, especially fluorine doping. Finally, the surface effects of electrode materials based on the nanocrystalline materials and on the “electrochemical grafting model” are elucidated. The material presented in the chapter concludes that the electrochemistry of nanocrystalline materials differs from that of traditional well-crystalline ones because of their significant surface effects, and the electrochemical properties of the doped-SnO2 show improved performance mainly due to increased conductivity.