Enhancement of rate capability in graphite anode by surface modification with zirconia

Zirconia coating the graphite was examined with a view to enhance the cycling stability of the graphite anode in Li-ion batteries. A thin zirconia film was produced on the graphite surface using an alkoxide precursor solution, followed by the conversion of the wet film into an oxide film by thermal annealing. The anode consisting of zirconia-treated graphite, acetylene black, and the binder (8:1:1) exhibits a capacity exceeding the theoretical value and a pronounced stability upon cycling even at a charge-discharge current rate as high as 3C. It is suggested that the combination of nanocrystalline-zirconia and the in situ formed surface films better protects graphite from destruction upon cycling. (C) 2002 The Electrochemical Society.