锂离子电池富镍正极材料基础科学问题:表面残锂及其去除  

Basic scientific problems of Ni rich cathode materials for Li-ion battery:Surface residual Li and its removal

作　　者：王鑫 陈欣 任莉 王硕 罗宏基 张军 吕根品 向伟[1] WANG Xin;CHEN Xin;REN Li;WANG Shuo;LUO Hongji;ZHANG Jun;LV Genpin;XIANG Wei(School of Materials,Chemistry and Chemical Engineering,Chengdu University of Technology,Chengdu 610059,China;Sichuan Changhong Green Environmental Technology LTD.,Chengdu 610059,China;Shaoguan HEC Technology R&D CO.,LTD.,Shaoguan 512000,China)

机构地区：[1]成都理工大学材料与化学化工学院,成都610059 [2]四川长虹格润环保科技股份有限公司,成都610059 [3]韶关东阳光科技研发有限公司,韶关512000

出　　处：《复合材料学报》2022年第1期97-110,共14页Acta Materiae Compositae Sinica

基　　金：国家自然科学基金(21805018);四川省科技厅应用基础研究项目(2020YJ0134)。

摘　　要：层状富Ni正极材料具有高可逆容量、低自放电性能和低成本优势,被认为是最有潜力的Li;电池正极材料。然而,材料结构不稳定、容量衰退和安全性差等问题,阻碍了富Ni正极材料的实际应用。当Ni含量大于80%时,富镍正极易与空气中的水分和CO_(2)反应,在材料表面生成Li_(2)CO_(3)、LiHCO_(3)、LiOH等残Li化合物。残Li存在不仅导致材料不稳定和电化学性能衰退,还造成电池安全问题。本文首先综述了残Li化合物的形成机制及其危害,再探讨了水洗过程中的水洗温度、时间、干燥温度等因素对材料性能的影响,并阐述了水洗造成结构衰退和容量衰减的机制。此外,还论述了其他去除残Li化合物的方法,特别是无水洗表面包覆的方法在去除残Li化合物影响方面呈现出巨大应用潜力。The layered Ni-rich cathode materials are considered as the most promising cathode materials for Li-ion batteries due to their high reversible capacity,low self-discharge performance and low cost.However,they have some disadvantages,such as the unstable material structure,capacity decay and poor safety,hindered their practical application.The Ni-rich cathode materials with nickel content over 80%are easy to react with moisture and CO_(2)in the air,generating residual Li compounds such as Li_(2)CO_(3),LiHCO_(3)and LiOH on the surface of materials.The presence of residual Li not only leads to structure instability and electrochemical performance degradation,but also causes battery safety problems.In this paper,the mechanism of the formation of residual Li and its hazards are reviewed.Then,the effect of factors (e.g.washing temperature,time,drying temperature,etc.) during water washing on the material property are discussed,and the mechanisms of structural deterioration and capacity degradation induced by water washing are elaborated.Lastly,other methods for removing residual Li compounds are introduced,especially the non-washing surface coating method,which shows great application potential in removing the influence of residual Li compounds.

关 键 词：纳米材料 制备 表面 富Ni正极 残锂 水洗 锂离子电池 

分 类 号：TM912[电气工程—电力电子与电力传动]