氟化尖晶石锰酸锂LiMn_2O_(4-z)F_z锂电池正极材料研究

Fluorinated spinel lithium manganese oxide LiMn_2O_(4-z)F_z as cathode material for lithium ion batteries

研究了电动工具、电池车等对安全性和成本要求较高的应用领域所需要的改性尖晶石型LiMn2O4电池正极材料。首先研究了LiMn2O4与LiF混合物的热处理反应过程,采用LiF对预先合成的LiMn2O4进行后处理,并研究了处理温度对材料的比表面积和高温循环性能的影响。结果表明,LiF/LiMn2O4混合体系在500℃以上开始反应,所形成材料的特性发生了明显的变化;热处理温度越高,形成的材料比表面积大幅度减小,由处理前的2.0m2/g减小为1.1m2/g;600℃条件下处理材料的首次比容量为118.1mAh/g,但是循环30次的容量保持率仍然可以达到89%。

The modified spinel battery cathode material LiMn2O4 required by the power tools, cell vehicles for the safety and cost-demanding applications was researched. The reaction process of mixture of LiMn2O4 with LiF while heating was investigated, and the thermal treating conditions of the mixture were optimized with respect to the relative surface area and cycling stability of the material at high temperature. The results show that the mixture of LiF/LiMn2O4 starts to react at above 500 ℃, the properties of the treated materials change substantially. The higher is the treating temperature, the relative surface area of material had a significant decrease, from 2.0 m2/g to 1.1 m2/g the first-time rational capacity of modified materials at 600 ℃ was 118.1 mAh/g, but the capacity retention rate after the 30 times cycle could still reach 89 %.