The spinel structured $LiMn_2O_4$was obtained by two consecutive heat treatment on xerogel; the first heat treatment was at $150^{circ}C$ and the second at $350^{circ}C$ was obtained by sol-gel process using an aqueous solution of lithium hydroxide and manganese acetate. The synthesized $LiMn_2O_4$ by the sol-gel process showed a discharge capacity of 88~56 mAh/g after 15 cycles in Li/lM $LiClO_4$(in PC)/$LiMn_2O_4$at a current density of 0.25 mA/$ extrm{cm}^2$ and the voltage ranged 3.5 V to 4.3 V. For the second heat treatment above $350^{circ}C$, $Mn_2O_3$was formed as a by-product during the synthesis of $LiMn_2O_4$. The heat treatment at $500^{circ}C$, for example, showed a lower discharge capacity 81~47 mAh/g, after the 15 charge/discharge cycles. The lower capacity was due to the increment of $Mn^{3+}$ ion and this phenomenon was in agreement with the Jahn-Teller distortion.