高性能LiNi0.7Co0.1Mn0.2O2正极材料合成工艺及电化学性能研究

通过化学共沉淀和高温固相反应法合成不同Li/M比(Li为锂元素的物质的量,M为过渡金属元素总物质的量)的LiNi0.7Co0.1Mn0.2O2正极材料,采用XRD、SEM、恒流充放电测试系统和电化学工作站研究Li/M比对材料结构、形貌和电化学性能的影响。结果表明,Li/M比为1.10的LiNi0.7Co0.1Mn0.2O2正极材料层状结构完整,颗粒形貌良好,电化学性能最优。0.2 C充放电条件下的首次放电比容量达到204.0 mAh/g;1.0 C充放电条件下循环充放50圈后放电比容量为187.0 mAh/g,容量保持率达到97.2%。

Study on the Synthesis Technology and Electrochemical Performance of High-performance LiNi0.7Co0.1Mn0.2O2 Cathode Material

The cathode material LiNi0.7Co0.1Mn0.2O2was synthesized by means of the high-temperature solidstate reaction between the co-precipitatedNi0.7Co0.1Mn0.2(OH)2 and LiOHpowders.Using X-ray diffraction(XRD),scanning electron microscope(SEM),galvanostatic charge/discharge battery test system and electrochemical workstation to research the effect of Li/M ratio on the structure,morphology and electrochemical performance.The results showed that the cathode material LiNi0.7Co0.1Mn0.2O2 obtained well-ordered structure and excellent electrochemical performance while the Li/M ratio was 1.10.The initial discharge capacity at 0.2 C rate is 204.0mAh/g,and the discharge capacity after 50 cycles at 1.0 C rate is 187.0 mAh/g,the capacity retention was high to 97.2%.