Studies of LiCoO2 coated with metal oxides

It has been reported that LiCoO2 coated with a metal oxide layer can deliver a capacity in excess of 140 mAh/g with improved capacity retention. Here, a commercial sample of LiCoO2 was coated with ZrO2, SiO2, and Al2O3 for comparative studies. Li/LiCoO2 cells using the coated LiCoO2 samples and a heat-treated control sample were charged and discharged between 3.6 and 4.5 V at a C/3 rate. All samples showed excellent capacity retention compared to the as-received commercial sample. Unlike literature reports, we find the capacity retention of coated LiCoO2 is independent of the specific oxide used for the coating. (C) 2003 The Electrochemical Society.