STUDIES ON AN LI-MN-O SPINEL SYSTEM (OBTAINED BY MELT-IMPREGNATION) AS A CATHODE FOR 4 V LITHIUM BATTERIES .1. SYNTHESIS AND ELECTROCHEMICAL-BEHAVIOR OF LIXMN2O4

An LixMn2O4 spinel phase is used as a cathode for 4 V lithium batterie s and is prepared by the melt-impregnation method, in which melted LiO H or LiNO3 is impregnated into MnO2 pores, then reacted with MnO2 at h igher temperature. The effect of synthesis conditions on the electroch emical properties is investigated extensively. For optimum synthesis, the spinel LixMn2O4 should be prepared in an N-2 atmosphere at a low t emperature of less than 750 degrees C and for a short time of less tha n 48 h. The optimum LiMn2O4 delivers an initial charge capacity of 135 mAh/g, and exhibits good rechargeability. The average specific capaci ty during first 50 cycles is about 120 mAh/g or more.