Synthesis of LiNixMn2-xO4 cathode materials by emulsion method and its electrochemical properties

Powder of the cathode material, LiNixMn2-xO4 (0 less than or equal to x less than or equal to 0.2) was prepared by emulsion method and calcined at 800 degrees C for 48 h in air. The calcined powder showed a spinel structure and a spherical morphology. The average particle size and the specific surface area were 0.17 mu m and 34 m(2)/g, respectively. Charge-discharge tests were carried out galvanostatically in a voltage range between 3.0 V and 4.5 V. The composition of LiNi0.025Mn1.975O4 showed an improved discharge capacity, 123.4 mA . h/g and a stable cycle life during charge-discharge cycling. The plateau range near 4.0 V became narrow as the amount of nickel increased. Another plateau range was observed near 4.6 V which became broader with increasing x.