Advanced oxide and metal powders for negative electrodes in lithium-ion batteries

In this study, tin dioxide, tin and bismuth have been envisioned as possible candidate to replace graphite negative electrodes in Li-ion batteries. Tin dioxide thin films and nanoscaled tin and bismuth powders have been synthesized by different techniques. Their electrochemical behaviors have been compared to electrodes made with standard commercially available powders. In all cases, nanoscaled materials have shown enhanced electrochemical properties compared to standard powders. SnO2 thin films exhibit a longer cycle life than tin dioxide powder. The capacities measured on both bismuth and tin nanoscaled materials were more important than for the same electrodes prepared by commercially available powders. Moreover, the values are close to those expected from the theoretical reactions. However, the cycling life of tin or bismuth electrodes is still the weak point of these systems. Subsequently, an optimized matrix is required in order to prevent capacity loss upon cycling. (C) 2002 Elsevier Science B.V All rights reserved.