Performance characteristics of Li//Li1±XCoO2 cells

Lithium cobalt oxides (LiCoO2) with varying lithium stoichiometries viz., 0.97, 1, 1.03, 1.06 and 1.1 have been prepared by a solid-state high temperature technique. Structural determination of the synthesized powders with X-ray diffraction (XRD) reveals single-phase materials while the surface morphologies investigated with scanning electron microscopy (SEM) indicate different particle orientation with increase in lithium content. Electrochemical galvanostatic cycling studies of the synthesized powders in lithium 2032 coin type cells in the voltage range 3.5-4.5 V suggest that initial capacity fading is minimum in samples with lithium stoichiochiometries of either 0.97 or 1.03 and stable capacities are attained after the initial 10 cycles. The effect of lithium stoichiometry on the performance of LiCoO2 in a lithium rechargeable cell is presented.