LiMn2O4 cathode material was prepared by high temperature ball milling combustion using lithium acetate, manganese (II) acetate tetrahydrate as raw materials and citric acid as fuel. The effects of milling temperature improving the electrochemical performance of LiMn2O4 were investigated. X-ray diffraction, scanning electron microscopy, galvanostatic testing, electrochemical impedance spectroscopy and cyclic voltammetry were used to analyze the as-prepared materials in this work. The experimental results showed that the best electrochemical performance of LiMn2O4 was obtained with material synthesized at 600 °C. The initial discharge capacities were 132, 121, 109, 93, 76 and 58 mAh g−1 at rates of 0.1, 0.5, 1.0 C, 2.0, 5.0 and 10 C, respectively. Moreover, after 50 cycles, at a rate of 0.1 C, the capacity of LiMn2O4 sample was 125 mAh g−1, and its capacity retention rate achieved 94.7%. It is concluded that this novel synthesis method is a promising method for preparation of LiMn2O4.