Fine LiCo1-xAlxO2 (0 <= x <= 0.05) cathode powders were prepared by the solid-state reaction method using nanosized Co1-xAlxOy (0 <= x <= 0.05) precursor powders with various concentrations of aluminum used as the dopant. The Co1-xAlxOy precursor powders prepared by spray pyrolysis had nanometer size and a regular morphology after post-treatment at 800 degrees C. The aluminum dopant decreased the mean particle sizes of the Co1-xAlxOy precursor powders and LiCo1-xAlxO2 cathode powders. The mean particle sizes of the LiCoO2 and LiCo0.95Al0.05O2 cathode powders were 1.1 and 0.52 mu m, respectively. The initial discharge capacities of the LiCoO2 and LiCo0.99Al0.01O2 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 LiCo0.99Al0.01O2, LiCo0.97Al0.03O2, and LiCo0.95Al0.05O2 cathode powders after the 50th cycle were 91, 84, and 82%, respectively, of their respective maximum discharge capacities. (C) 2008 Elsevier B.V. All rights reserved.