Preparation And Performance Study Of LiNi_0.80Co_0.1Mn_0.1O₂ Cathode Material For Lithium-ion Batterie

Rapid development in studies on high nickel LiNi1-x-yCoxMnyO2 has been achieved with the continuous research and developments in lithium ion cells.The material has been regarded as the most promising cathode for new generation lithium ion cells.For its high capacity,energy density and thermal stability and good cycleability,the composition LiNi0.8Co0.1Mn0.1O2(NCM)has received most investigation whose commercial viability has almost been reached.The work reviewed the research development for NCM,studied the solid state method for NCM synthesis,employed electrochemical techniques for synthesis parameter effects on NCM properties,and explored the electrochemical behavior of NCM on increasing Mn content.NCM was prepared via a solid state method and all products were characterized with charge-discharge,SEM,XRD,etc.The effects of synthesis parameters,lithium source,pre-sintering temperature and sintering temperature,on the electrochemical behavior,morphology and structure of NCM were investigated.The optimal conditions for NCM synthesis included LiOH·H2O used as lithium source and pre-sintering at 500℃ in air for 8h followed by sintering at 800℃ in OO2 for 24h.In 3.0-4.35V and at 0.2C,the as-prepared NCM delivered an initial capacity of 195mAh/g,highest capacity of 195mAh/g and capacity retention of 83.45%over 20 cycles.When LiNO3 was used the optimal conditions were pre-sintering at 400℃ in air for 8h followed by sintering at 800℃ in O2 for 24h.The resultant NCM exhibited an initial capacity of 207.3mAh/g,highest capacity of 210.5mAh/g and capacity retention of 95.4%over 20 cycles at 0.2C in 3.0-4.35V.Mn content in NCM was changed and its effect on the cathode performance was explored.The electrochemical behavior,morphology and structure were investigated on appropriate Mn increases in NCM.In 3.0-4.35V and at 0.2C,High manganese LiNi0.72Co0.1Mn0.18O2 displayed an initial capacity of 179.5mAh/g,highest capacity of 181.7mAh/g and capacity retention of 89.9%over 30 cycles.Low manganese LiNi0.76Co0.1Mn0.14O2 and LiNi0.80Co0.1Mn0.10O2 demonstrated initial capacities of 171.7 and 185.9mAh/g,highest capacities of 172.9 and 190.6mAh/g and capacity retention of 86.3%and 79.9%,respectively,over 30 cycles at 0.2C in 3.0-4.35V.The above results indicated that NCM showed an improved cycleability on an appropriate increase in Mn content with a decrease in Ni content.