A simple approach, for the first time, was presented for in situ preparation of the CuS cathode. The obtained CuS cathodes were investigated by the measurements of X-ray diffraction pattern, scanning electronic microscopy, and electrochemical performance. The results indicate the CuS cathodes are composed of plenty of nano flakes, which construct a large 3-D net structure. Moreover, the CuS cathodes exhibit reversible capacity of 447.4, 414.1, 389.9 and 376.0mAhg−1 at 0.2C, 0.5C, 1C and 2C respectively and excellent cycle stability for more than 100 cycles. The possible mechanism of the unique stability of the CuS cathode was discussed.