The cathode material, LiFexMn2 - xO4 (0.0 less than or equal to x less than or equal to 0.2) was prepared by the emulsion method and calcined at 800 degreesC for 48 h in air. The calcined powder had a spinel structure and was of spherical shape. The average particle size and the specific surface area were 0.20 mum and 3.4 m(2)/g, respectively. The composition LiFe0.05Mn1.95O4 showed the largest discharge capacity, 105 mA h/g, and 9% of capacity deterioration after 30 charge-discharge cycles. As the content of Fe increased, the discharge capacity decreased, and the two plateaus at 4.1 and 3.9 V seen in LiMn2O4] disappeared. It is considered that Fe addition into LiMn2O4 inhibited the formation of Li0.5Mn2O4 phase.