Composite negative electrodes for lithium ion cells

In this study, the possible uses of SnO2 and SnS2 as anodes in lithium-ion batteries have been investigated. Powders of both materials have been synthesized. Structural as well as electrochemical characterizations have been performed. Both systems seem to follow similar mechanisms leading to the formation of metallic tin and Li2O or Li2S after the first cycle. SnO2 and SnS2 powders exhibit similar irreversible capacities on the first cycle in accordance with the expected theoretical values. However, the reversible capacity is much higher in the case of SnO2. Synthesis methods as well as differences in the inactive component of the electrode can explain the poor electrochemical performances observed for SnS2 powder. Despite the drawbacks of the sulfide system, this study indicates that not only Li2O can be used as an inactive matrix in composite electrodes. (C) 1998 Published by Elsevier Science B.V. All rights reserved.