CHARACTERIZATION OF LT-LIXCO1-YNIYO2 ELECTRODES FOR RECHARGEABLE LITHIUM CELLS

LT-LiC0.9Ni0.1O2 prepared at 400 degrees C with a structure that is in termediate between an ideal lithiated spinel and a layered structure h as been investigated as an electrode in rechargeable Lithium cells; it delivers a voltage vs. pure lithium that is significantly lower than the voltage provided by its high-temperature analogue, HT-LiCo0.9Ni0.1 O2, (synthesized at 900 degrees C). The rechargeability of Li/LT-LiCo0 .9Ni0.1O2 cells can be improved by leaching some lithium and a small a mount of cobalt from LT-LiCo0.9Ni0.1O2 by acid treatment and loading t he cells in a charged state. The improvement in electrochemical perfor mance is attributed to the formation of a defect spinel phase Li-0.8[C o1.6Ni0.2]O-4 in which the lithium ions adopt the tetrahedral A sites and the cobalt and nickel ions the B sites of an A[B-2]O-4 spinel.