Probing the Air Storage Failure Mechanism of Ni-Rich Layered Cathode Materials  

作　　者：Qingyu Dong Ruowei Yi Jizhen Qi Yanbin Shen Liwei Chen 董庆雨;易若玮;齐楫真;沈炎宾;陈立桅(i-Lab,CAS Center for Excellence in Nanoscience,Suzhou Institute of Nano-Tech and Nano-Bionics(SINANO),Chinese Academy of Sciences(CAS),Suzhou 215123,China;In Situ Center for Physical Sciences,School of Chemistry and Chemical Engineering,Shanghai Jiaotong University,Shanghai 200240,China)

机构地区：[1]i-Lab,CAS Center for Excellence in Nanoscience,Suzhou Institute of Nano-Tech and Nano-Bionics(SINANO),Chinese Academy of Sciences(CAS),Suzhou 215123,China [2]In Situ Center for Physical Sciences,School of Chemistry and Chemical Engineering,Shanghai Jiaotong University,Shanghai 200240,China

出　　处：《Chinese Physics Letters》2022年第3期105-108,共4页中国物理快报（英文版）

摘　　要：Ni-rich layered oxide cathode materials,such as LiNi_(0.83)Co_(0.12)Mn_(0.05)O_(2)(NCM811),exhibit high specific capacity and low cost,and become cathode material preference of high-energy-density Li-ion batteries.However,these cathode materials are not stable and will form Li-poor reconstructed layers and alkaline compounds(Li_(2)CO_(3),LiOH)on the surface during the storage and processing in humid air,resulting in serious deterioration of electrochemical properties.During the past two decades,the consensus on the surface instability mechanism during humid air storage has not been reached.The main controversy focuses on the unstable octahedron mechanism and the Li/H exchange mechanism.Herein,we investigate the instability mechanism in the humid air by conducting scanning electronic microscopy,scanning transmission electron microscopy,and x-ray photoelectron spectroscopy analysis on NCM811 samples stored in designed atmospheres,etc.,and realize that the surface instability of the NCM811 during storage should be mainly originated from Li/H exchange when it contacts with moisture.

关 键 词：MECHANISM MOISTURE STORAGE 

分 类 号：TM912[电气工程—电力电子与电力传动] TQ131.11[化学工程—无机化工]