Solid-state synthesis and characterization of LiCoO2 and LiNiyCo1−y solid solutions

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