Electrochemical performance of ball-milled ZnO-SnO2 systems as anodes in lithium-ion battery

ZnO displays similar redox and alloying chemistry to the tin oxides on Li i nsertion. It might, therefore, be expected to be an interesting network mod ifier for tin oxides. ZnO/SnO2 composites show degradation in cycling perfo rmance, however, for low ZnO levels, cyclability is improved by some millin g, however, for high ZnO levels milling degrades performance, probably due to the increase of ZnO activity. On testing ZnO, it is found that it cycles very poorly. Both electrochemical and X-ray studies indicate that highly c rystalline LixZn alloys are formed. It seems that the high degree of crysta llisation on insertion is the determinant factor leading to the poor perfor mance of ZnO and ZnO/SnO2 composites compared to SnO2. (C) 2001 Elsevier Sc ience B.V. All rights reserved.