Solid solutions of compositions LiNiyCo1-yO2 (y = 0.0, 0.1 and 0.2) were pr
epared by solid-state fusion synthesis from carbonate precursors, Material
characterization was carried out using XRD. Formation mechanisms of the pro
ducts are discussed in the light of TG/DTA results, Nickel-containing compo
sitions gave higher discharge capacities and smaller hystereses in their ch
arge-discharge profiles which make them more attractive than pristine LiCoO
2 as cathode materials in high-energy lithium cells. The lower loss in capa
city per cycle for-cells with unsubstituted LiCoO2, as determined from cycl
ing studies up to 25 cycles, makes it more suitable than the substituted on
es for long cycle-life cells with low capacity fade.