Abstract: A method of preparation of spherical tricobalt tetraoxide, including at least oxidizing a bivalent cobalt salt in a wet environment and in the presence of a precipitant, a complexing agent, and an oxidant to yield spherical cobalt oxyhydroxide.cobalt hydroxide according to the following equation Co2++3OH?+O?CoOOH.Co(OH)2; oxidizing the spherical hydroxy cobalt oxyhydroxide.cobalt hydroxide to yield spherical tricobalt tetraoxide according to the following equation 6CoOOH.Co(OH)2+O?4Co3O4+9H2O; and roasting the spherical tricobalt tetraoxide at low or intermediate temperature to yield a black powder. The method is easily practiced and suitable for mass production, and the resultant spherical tricobalt tetraoxide has stable structure, reliable properties, and high activity.

Abstract: A method of preparation of spherical tricobalt tetraoxide, including at least oxidizing a bivalent cobalt salt in a wet environment and in the presence of a precipitant, a complexing agent, and an oxidant to yield spherical cobalt oxyhydroxide.cobalt hydroxide according to the following equation Co2++3OH?+O?CoOOH.Co(OH)2; oxidizing the spherical hydroxy cobalt oxyhydroxide.cobalt hydroxide to yield spherical tricobalt tetraoxide according to the following equation 6 CoOOH.Co(OH)2+O?4 Co3O4+9 H2O; and roasting the spherical tricobalt tetraoxide at low or intermediate temperature to yield a black powder. The method is easily practiced and suitable for mass production, and the resultant spherical tricobalt tetraoxide has stable structure, reliable properties, and high activity.

Abstract: A method of preparing a cobalt and lithium ion-coated nickel and manganese-based cathode material, including at least: (a) coating a layer of cobalt hydroxide on a substrate of Ni0.5Mn0.5(OH)2 to yield y(Ni0.5Mn0.5(OH)2)·(1-y)(Co(OH)2) (0.2?y?0.8), (b) adding Lithium, and (c) sintering at 750-1000° C. for 8-24 hrs to yield LiNi0.5-xCo2xMn0.5-xO2 (0.03<x?0.4). The method is easy for practice and suitable for mass production, and the cathode material prepared by the method, i.e., LiNi0.5-xCo2xMn0.5-xO2 (0.03<x?0.4) features high specific capacity, stable cycle performance, and low cost.