Studies on an Li---Mn---O spinel system (obtained by melt-impregnation) as a cathode for 4 V lithium batteries part 1. Synthesis and electrochemical behaviour of LixMn2O4

An LixMn2O4 spinel phase is used as a cathode for 4 V lithium batteries and is prepared by the melt-impregnation method, in which melted LiOH or LiNO3 is impregnated into MnO2 pores, then reacted with MnO2 at higher temperature. The effect of synthesis conditions on the electrochemical properties is investigated extensively. For optimum synthesis, the spinel LixMn2O4 should be prepared in an N2 atmosphere at a low temperature of less than 750 °C and for a short time of less than 48 h. The optimum LiMn2O4 delivers an initial charge capacity of 135 mAh/g, and exhibits good rechargeability. The average specific capacity during first 50 cycles is about 120 mAh/g or more.