机械活化氧化法制备锰酸锂及其性能研究

Synthesis of LiMn_2O_4 cathode material by mechanical-activation-oxidation processing and its performance

以高纯金属锰粉和碳酸锂为原料,通过机械活化氧化法合成了尖晶石LiMn2O4材料。采用X射线衍射（XRD）和扫描电镜（SEM）对LiMn2O4样品结构及形貌进行表征,用充放电测试和交流阻抗技术对LiMn2O4样品进行电化学性能研究。结果表明,所制备的LiMn2O4具有完整的尖晶石型结构,且颗粒形貌规整,颗粒大小均匀。所制备的LiMn2O4材料室温（25℃）在3.0～4.3V电压范围,在0.1C倍率下首次放电比容量为125.8mAh/g；2C首次放电容量为120.1mAh/g,300次循环后放电容量保持103.9mAh/g,容量保持率为86.51%。且样品具有较好的高温性能和较小的阻抗。

LiMn2O4has been successful synthesized by the mechanical-activation-oxidation method from high purity manganese powder and Li2CO3.The crystal structure,morphology and electrochemical performance of LiMn2O4have been characterized by X-ray diffraction（XRD）,scanning electron microscopy（SEM）,chargedischarge test and AC impedance.The results show that the LiMn2O4has spinel structure and exhibits uniform particle size distribution.The initial discharge capacities of the LiMn2O4are as high as 125.8mAh/g at 0.1C and 120.1mAh/g at 1Cin the voltage range of 3.0-4.4Vat 25 ℃,especially,the discharge capacity retains 103.9mAh/g at 1Cafter 500cycles.Besides,the as-prepared LiMn2O4presents good high temperature performance and smaller electrochemical impedance.