Room-temperature mechanosynthesis of Ni3S2 as cathode material for rechargeable lithium polymer batteries

The formation of Ni3S2 was realized by mechanical alloying with metallic nickel and sulfur powder as precursors. The products were characterized by X-ray diffraction, thermoanalysis, and scanning electron microscopy. Electrochemical properties of Li/P(EO)(20)Li(CF3SO2)(2)N-10 wt % gamma-LiAlO2/Ni3S2 cells were also presented. The initial discharge capacity of Ni3S2 was 304 mAh g(-1), with a platform at about 1.4 V vs Li/Li+. A capacity fading rate of 0.5% per cycle was achieved within 100 cycles. The charge-discharge mechanism of Ni3S2 was implied by the analysis of the charge-discharge potential profiles, the cyclic voltammetry traces, and the ex situ XRD patterns of the Ni3S2 cathode. (c) 2006 The Electrochemical Society.