高浓度下溶剂热法制备锂离子电池富锂正极材料

Preparation of Lithium-rich Cathode Materials for Lithium-ion Batteries by Solvothermal Method at High Concentration

溶剂热法因具有操作简单、封闭体系易于控制等特点已然成为目前实验室制备富锂正极材料的一种高效方法。目前报导的实验室制法往往在低浓度下进行,限制了实际生产需求。高浓度下利用溶剂热法制备优良性能的富锂正极材料得到了实现,同时利用扫描电子显微镜、透射电子显微镜、能谱分析、激光粒度分析和恒电流充放电测试等研究了不同浓度对其结构和电化学性能的影响。结果表明:乙酸锂浓度为1.0 M时制备的材料具有良好的六边形结构,粒径小,分布均匀,0.1C时放电比容量高达296.1mA·h/g。50次循环后,库仑效率仍保持在97%以上。

The solvothermal method has become an efficient method for preparing Li-rich cathode materials in the laboratory due to the simple operation and easy control of the closed system.Currently reported laboratory processes are often carried out at low concentrations,limiting the actual production requirements.In this paper,the preparation of Li-rich cathode material by solvothermal method at high concentration was realized,the effect of different concentrations on the structure and electrochemical performances was also investigated by Scanning Electron Microscope,Transmission Electron Microscopy,Energy Dispersive Spectrometer,Laser Particle Size Analysis,Galvanostatic Charge-Discharge Test,etc.The results showed that,the material exhibited the well-ordered hexagonal shape with smaller particle size and uniform distribution when the concentration of lithium acetate was 1.0 M and a discharge capacity was up to 296.1 m A·h/g at 0.1 C.The coulombic efficiencies were mostly over 97%during the following 50 cycles.