Effect of molar ratio of Li₂CO₃/MnO₂ on characteristic of the Lithium Manganate Synthesized via High Temperature Ball Milling Method

摘要

Lithium manganite (LiMn2O4) cathode materials were synthesized with Li2CO3, MnO2 and polyethylene glycol 12000 as raw materials via high temperature ball milling method, and the effect of the value of the molar ratio of Li/Mn on the impurity, structure, morphology, and electrochemical performance was experimentally investigated in this work. Some impurity of Li1.4Mn2O4 was detected in the L-1.15 (nLi:nMn = 1.15:2), and the lithium source influenced the uniformity of particles. Some button batteries were assembled with the lithium manganite and the electrochemical performance was tested. L-1.1 (nLi:nMn = 1.1:2) exhibited the optimal electrochemical performance: initial discharge capacities were 121.5, 109.5, 98.3, 86.5 and 70.2 mAhg-1 at rates of 0.1, 0.5, 1.0, 2.0 and 5.0 C, respectively. After 100 cycles, the capacity was 89.5 mAhg-1 at rate of 1.0 C and the capacity retention was 91.0%.