LiCo_1-xAl_xO₂ (0 ≤ x ≤ 0.05) cathode powders prepared from the nanosized Co_1-xAl_xO_y precursor powders

Fine LiCo_1-xAl_xO₂ (0 ≤ x ≤ 0.05) cathode powders were prepared by the solid-state reaction method using nanosized Co_1-xAl_xO_y (0 ≤ x ≤ 0.05) precursor powders with various concentrations of aluminum used as the dopant. The Co_1-xAl_xO_y precursor powders prepared by spray pyrolysis had nanometer size and a regular morphology after post-treatment at 800 °C. The aluminum dopant decreased the mean particle sizes of the Co_1-xAl_xO_y precursor powders and LiCo_1-xAl_xO₂ cathode powders. The mean particle sizes of the LiCoO₂ and LiCo_0.95Al_0.05O₂ cathode powders were 1.1 and 0.52 μm, respectively. The initial discharge capacities of the LiCoO₂ and LiCo_0.99Al_0.01O₂ cathode powders were 151 and 161 mAh g^-1, respectively. The discharge capacity of the LiCoO₂ cathode powders after the 50th cycle was 90% of their maximum discharge capacity. However, the discharge capacities of the LiCo_0.99Al_0.01O₂, LiCo_0.97Al_0.03O₂, and LiCo_0.95Al_0.05O₂ cathode powders after the 50th cycle were 91, 84, and 82%, respectively, of their respective maximum discharge capacities.