Synthesis and properties of single-crystal Ni-rich cathode materials in Li-ion batteries  

锂离子电池高镍单晶正极材料的合成与性能

作　　者：Shi-jie LU Yang LIU Zhen-jiang HE Yun-jiao LI Jun-chao ZHENG Jing MAO Ke-hua DAI 路士杰;刘洋;贺振江;李运姣;郑俊超;毛景;代克化(中南大学冶金与环境学院,长沙410083;中南大学难冶有色金属资源高效利用国家工程实验室,长沙410083;中南大学先进电池材料教育部工程研究中心,长沙410083;郑州大学材料科学与工程学院,郑州450001;天津师范大学化学学院,天津300387)

机构地区：[1]School of Metallurgy and Environment,Central South University,Changsha 410083,China [2]National Engineering Laboratory for High Efficiency Recovery of Refractory Nonferrous Metals,Central South University,Changsha 410083,China [3]Engineering Research Center of the Ministry of Education for Advanced Battery Materials,Central South University,Changsha 410083,China [4]School of Materials Science and Engineering,Zhengzhou University,Zhengzhou 450001,China [5]College of Chemistry,Tianjin Normal University,Tianjin 300387,China

出　　处：《Transactions of Nonferrous Metals Society of China》2021年第4期1074-1086,共13页中国有色金属学报（英文版）

基　　金：financial supports from the National Natural Science Foundation of China (51974368);the Fundamental Research Funds of the Central South University,China。

摘　　要：Single-crystal Ni-rich cathode material LiNi0.88Co0.09Al0.03O2(SC) was synthesized by a high-temperature solid-state calcination method. Physicochemical properties of primary and delithiated SC samples were investigated by X-ray diffractometry, X-ray photoelectron spectroscopy, and transmission electron microscopy. Electrochemical performance was characterized by long-term cycling, cyclic voltammetry, and in-situ impedance spectroscopy. The results indicated that high temperature rendered layered oxides to lose lithium/oxygen in the interior and exterior, and induced cationic disordering. Besides, the solid-phase synthesis process promoted phase transformation for electrode materials, causing the coexisting multi-phase in a single particle. High temperature can foster the growth of single particles, but it caused unstable structure of layered phase.通过高温固相焙烧法合成高镍单晶正极材料LiNi0.88Co0.09Al0.03O2。采用XRD、XPS、TEM等技术研究初始样品和脱锂化高镍单晶材料的物理化学性能;采用长循环测试、循环伏安法和原位阻抗分析表征其电化学性能。研究结果表明:在高温处理过程中,样品的内部和表面发生锂氧损失和相转变现象,材料在固相合成反应过程中会加剧相转变,并在单一颗粒上形成多相共存状态;高温可以促进一次颗粒生长,但对单晶颗粒的稳定层状结构有一定的损害。

关 键 词：lithium-ion battery cathode material SINGLE-CRYSTAL electrochemical performance phase transformation 

分 类 号：TM912[电气工程—电力电子与电力传动] TQ138.13[化学工程—无机化工]