MgAl2O4 spinel-coated LiCoO2 as long-cycling cathode materials

The enhanced cyclability of LiCoO2 coated with MgAl2O4 is described. A TEM examination of the microstructure of the coated particles revealed that the spinel formed a rather uniform coating over the cathode material. XRD data suggested the presence of substitutional oxides on the surface of the cathode particles. R-factor values from XRD studies and galvanostatic cycling studies suggested that a coating level of 1.0 wt.% gave an optimal performance in capacity and cyclability. A commercial sample of LiCoO2 coated with 1.0 wt.% of spinel registered a five-fold improvement in cyclability. The improved cyclability is attributed to a suppression of the cycle-limiting phase transitions that accompany the charge-discharge processes.