This paper describes the fabrication of LiMn2O4/graphite batteries and their performance after storage at room temperature. The discharge capacity and cyclic performance of the batteries were investigated. Compared with the batteries without storage, those after storage show better cyclic performance with a capacity retention ratio of 94.2% after 100cycles, yet deliver lower capacity. The ratio of capacity recovery after storage at room temperature for a month is 96.3%. The reason for the capacity fading and better cyclic performance was studied with XRD, SEM, EDS, XPS, cyclic voltammograms and AC impedance. It is found that the lattice parameter of LiMn2O4 shrinks after storage. Mn is dissolved into the electrolyte and deposited on the anode, and the electrode surface is covered by MnO2. The migration resistance of LiMn2O4/electrolyte is increased from 20.28 to 53.31Ω after storage due to the covered MnO2. But the deposited MnO2 also separates the LiMn2O4 from electrolyte, which can improve the cyclic performance.