Abstract: (NH4)2CO3 was added into mixed solution contained Li+, Co2+, Ni2+ and Mn2+ ions as a precipitant. The mixing precipitation precursors were prepared by one-step co-precipitation reaction. After being dried and ground, the precursors were sintered under different sintering temperatures(700-1 000 ℃) and different sintering times(6-24 h), and then LiNi1/3Co1/3Mn1/3O2 powders were obtained. The microstructures and electrochemical properties of the as-prepared powders were examined using X-ray diffraction(XRD), scanning electron microscopy(SEM), cyclic voltammetry(CV) and electrochemical impedance. The results show that the obtained LiNi1/3Co1/3Mn1/3O2 powders are pure -NaFeO2 layered structure;the powders are uniform and exhibit excellent discharge specific capacitance and lower impedance. After sintered at 900 ℃ for 12 h, the obtained LiNi1/3Co1/3Mn1/3O2 powder exhibits the optimum electrochemical performance. The specific capacitance of the LiNi1/3Co1/3Mn1/3O2 powders can reach 399.46 Fg-1 within potential range of (0-1.4) V at a scanning rate of 5 mVs-1 in 1 molL-1 Li2SO4 solution. And the powders also have the lowest impedance.