Physical and electrochemical properties of spherical Li 1+ x(Ni 1/3Co 1/3Mn 1/3) 1− xO 2 cathode materials

Abstract

A (Ni 1/3Co 1/3Mn 1/3)CO 3 precursor with an uniform, spherical morphology was prepared by coprecipitation using a continuously stirred tank reactor method. The as-prepared spherical (Ni 1/3Co 1/3Mn 1/3)CO 3 precursor served to produce dense, spherical Li 1+ x (Ni 1/3Co 1/3Mn 1/3) 1− x O 2 (0 ≤ x ≤ 0.15) cathode materials. These Li-rich cathodes were also prepared by a second synthesis route that involved the use of an M 3O 4 (M = Ni 1/3Co 1/3Mn 1/3) spinel compound, itself obtained from the carbonate (Ni 1/3Co 1/3Mn 1/3)CO 3 precursor. In both cases, the final Li 1+ x (Ni 1/3Co 1/3Mn 1/3) 1− x O 2 products were highly uniform, having a narrow particle size distribution (10-μm average particle size) as a result of the homogeneity and spherical morphology of the starting mixed-metal carbonate precursor. The rate capability of the Li 1+ x (Ni 1/3Co 1/3Mn 1/3) 1− x O 2 electrode materials, which was significantly improved with increased lithium content, was found to be better in the case of the denser materials made from the spinel precursor compound. This result suggests that spherical morphology, high density, and increased lithium content were key factors in enabling the high rate capabilities, and hence the power performances, of the Li-rich Li 1+ x (Ni 1/3Co 1/3Mn 1/3) 1− x O 2 cathodes.