Investigation of Electrochemical Properties of Tin-based Composite Oxide Glasses

초록

In recent years, the rechargeable Li-ion battery is an important energy source for many potable applications such as cell phone, smart card, PDA, and so on. Therefore, there has been a growing interest in the development of new negative electrode materials for rechargeable lithium batteries. The focus of development is finding new electrode materials with better safety and higher energy densities (larger gravimetric and volumetric capacities) for smaller and lighter products. Several materials are studied as candidates of anode materials. Among the suggested anode materials, tin-based composite oxide materials (TCO) are advantageous over carbon due to their higher volumetric (four times) and gravimetric (two times) capacity. However, tin-based composite oxide materials have a major drawback of the irreversible capacity (theoretically, 31.3% for SnO and 47.6% for SnO2) due to the formation of Sn grain and amorphous Li2O during the initial electrochemical cycle. As an alternative approach, tin-based composite oxides including small amount of Li2O might be lead to improved cyclability (less capacity fading) in comparison to the use of pure Sn metal as the electrode. In this study, the tin-based composite oxide of the Li2O-SnO-B2O3-P2O5 system has been prepared by melt-quenching method. The microstructural variation and electrochemical properties of this composite oxide were investigated at various SnO and Li2O contents.