5V尖晶石LiNi0.5Mn1.5O4锂离子电池正极材料制备及Mn^3＋的影响

摘要

Three spinel LiNi0.5Mn1.5O4 samples with different amount of Mn3＋ were prepared by the method of oxalate-coprecipitation.The XRD,SEM and electrochemistry measurements were used for characterization and testing the samples.The results showed that space group and Mn3＋ content will be influenced by annealing temperature,the best electrochemical performance has achieved from sample heated at 650℃ followed by 850℃ annealling.In addition,moderate amount of Mn^3＋ exhibits a positive effect on improving specific capacity and rate capability.%采用前驱体草酸盐共沉淀法合成了三种具有不同Mn^3＋含量的尖晶石镍锰酸锂正极材料,并对合成的样品进行了晶体结构、微观形貌及电化学性能等方面的表征和测试,结果发现,热处理温度的不同将影响材料的结晶结构和Mn3＋含量。其中,经850℃烧结后650℃退火处理的样品显示了最好的电化学性能,比容量达到130 mAh/g以上,倍率性能良好。同时也表明适量Mn^3＋在改善材料比容量、倍率性能等方面也具有积极作用。