一次颗粒尺寸对高镍三元材料的影响  

Effects of primary particle size on high-nickel ternary material

作　　者：谭仕荣 訚硕 董阳阳 TAN Shirong;YIN Shuo;DONG Yangyang(Hunan CNGR New Energy Science&Technology Co.,Ltd.,Changsha 410625,Hunan,China)

机构地区：[1]湖南中伟新能源科技有限公司,湖南长沙410625

出　　处：《电池》2025年第2期297-302,共6页Battery Bimonthly

摘　　要：为探究一次颗粒尺寸对高镍镍钴锰(NCM)三元正极材料电化学性能的作用规律,通过改变共沉淀法中的pH值、氨质量浓度、气体的种类等参数,制备具有不同一次颗粒尺寸的高镍NCM三元前驱体Ni 0.90 Co 0.08 Mn 0.02(OH)2,再与氢氧化锂混合烧结,得到具有不同一次颗粒尺寸的高镍NCM三元正极材料。以1.0 C在2.8~4.3 V循环200次,小、中、大等3种一次颗粒尺寸的高镍NCM三元正极材料,容量保持率分别为65.41%、75.98%和78.95%。在较低pH值、14 g/L氨质量浓度、空气氛围等条件下合成的前驱体,大尺寸一次颗粒之间具有自支撑作用,可提升正极材料二次颗粒的机械强度,缓解循环过程中正极材料因开裂和副反应发生导致的不可逆相变问题,具有较好的循环稳定性和安全性。In order to investigate the patterns of the size effect of primary particles on the electrochemical performance of high-nickel nickel-cobalt-manganese(NCM)ternary cathode materials,the parameters of the co-precipitation method,such as pH value,the mass concentration of ammonia and the kind of gas are changed,high-nickel NCM precursor materials Ni 0.90 Co 0.08 Mn 0.02(OH)2,which have different sizes of primary particles,are prepared.The precursors are then mixed and sintered with lithium hydroxide,obtaining the high-nickel NCM ternary cathode materials with different primary particle sizes.After 200 cycles in 2.8-4.3 V at a rate of 1.0 C,the capacity retention rates of high-nickel NCM ternary cathode materials with small,medium and large primary particle sizes are 65.41%,75.98%and 78.95%,respectively.The precursor synthesized under the conditions of low pH value,14 g/L ammonia mass concentration and air atmosphere has a self-supporting effect between large-sized primary particles,which improves the mechanical strength of the secondary particles of the cathode material,alleviates the irreversible phase transition caused by cracking and side reactions of the cathode material during the cycle,leading to better cycle stability and safety features.

关 键 词：锂离子电池 正极材料 高镍三元材料 前驱体 一次颗粒 自支撑颗粒 

分 类 号：TM912.9[电气工程—电力电子与电力传动] TD98[矿业工程—选矿]