The energy storage device of the coal mine system adopted the mine flameproof ( intrinsic safty ) type lithium ion battery power supply, the core component of the power supply is Li ion battery. In order to ensure the safe use of lithium ion battery underground, the performance of the large capacity mineral storage lithium ion battery was tested and analyzed and the safety test was studied in this paper. Cycle life of lithium ion batteries was studied under different conditions. In conjunction with results from XRD， FTIR, X-ray diffraction and AC impedance tests，which showed that 25℃、100% simulated operating condition、 rating cycle 600 times, equivalent to five years of working, the capacity decayed about 5.6%.