二氧化锰还原法制备锰酸锂材料及其性能研究

采用二氧化锰还原法制备了锰酸锂前驱体, 将前驱体在不同温度下进行热处理, 制得尖晶石型锰酸锂。利用AAS、滴定法、XRD、SEM表征样品的元素含量、晶体结构、形貌和粒径, 并研究了不同热处理温度对锰酸锂电化学性能的影响。结果表明, 通过二氧化锰还原法合成出了具有一定尖晶石结构的锰酸锂前驱体。当热处理温度为800 ℃时, 锰酸锂的导电性最佳, 0.2C放电容量为132.7 mAh/g, 0.5C放电容量为123.9 mAh/g, 循环10次后, 容量衰减5.97%。

Preparation of LiMn2O4 Cathode Materials by MnO2 Reduction Method and Their Performances

Precursors of LiMn₂O₄ were prepared by MnO₂ reduction method. The precursors were subjected to heat treatment at different temperatures to obtain spinel-type LiMn₂O₄. The element content, crystalline structure, morphology and particle size of the samples were characterized by AAS, titration, XRD and SEM. The effect of different temperature for heat treatment on electrochemical properties of LiMn₂O₄ was investigated. Results show that the precursor of LiMn₂O₄ with certain spinel structure could be synthesized by MnO₂ reduction method. The LiMn₂O₄ sample treated at 800 ℃ shows the best electrical conductivity. The discharge capacity is 132.7 mAh/g at 0.2C-rate. The discharge capacity is 123.9 mAh/g at 0.5C-rate. The capacity attenuation rate is 5.97% after 10 charge-discharge cycles.