Operando chemo-mechanical evolution in LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)cathodes  

作　　者：Yi Zhang Shuaipeng Hao Fei Pei Xiangpeng Xiao Chang Lu Xing Lin Zhe Li Haijin Ji Yue Shen Lixia Yuan Zhen Li Yunhui Huang 

机构地区：[1]State Key Laboratory of Material Processing and Die&Mould Technology,School of Materials Science and Engineering,Huazhong University of Science and Technology,Wuhan 430074,China [2]School of Optical and Electronic Information,National Engineering Laboratory for Next Generation Internet Access System,Wuhan National Laboratory for Optoelectronics,Huazhong University of Science and Technology,Wuhan 430074,China [3]Gatan Inc.&EDAX LLC.,AMETEK Commercial Enterprise(Shanghai)Co.,Ltd.,Pilot Free Trade Zone,Shanghai 200131,China [4]Department of Physics,The Chinese University of Hong Kong,Hong Kong 999077,China

出　　处：《National Science Review》2024年第9期247-257,共11页国家科学评论（英文版）

基　　金：supported by the National Natural Science Foundation of China(5202780089).

摘　　要：Ni-rich LiNi_(x) Co_(y) Mn_(z)O_(2)(NCM xyz,x+y+z=1,x≥0.8)layered oxide materials are considered the main cathode materials for high-energy-density Li-ion batteries.However,the endless cracking of polycrystalline NCM materials caused by stress accelerates the loss of active materials and electrolyte decomposition,limiting the cycle life.Hence,understanding the chemo-mechanical evolution during(de)lithiation of NCM materials is crucial to performance improvement.In this work,an optical fiber withμεresolution is designed to in operando detect the stress evolution of a polycrystalline LiNi_(0.8) Co_(0.1) Mn_(0.1) O_(2)(P-NCM811)cathode during cycling.By integrating the sensor inside the cathode,the stress variation of P-NCM811 is completely transferred to the optical fiber.We find that the anisotropy of primary particles leads to the appearance of structural stress,inducing the formation of microcracks in polycrystalline particles,which is the main reason for capacity decay.The isotropy of primary particles reduces the structural stress of polycrystalline particles,eliminating the generation of microcracks.Accordingly,the P-NCM811 with an ordered arrangement structure delivered high electrochemical performance with capacity retention of 82%over 500 cycles.This work provides a brand-new perspective with regard to understanding the operando chemo-mechanical evolution of NCM materials during battery operation,and guides the design of electrode materials for rechargeable batteries.

关 键 词：Ni-rich layered oxide cathode in operando stress monitoring POLYCRYSTALLINE chemo-mechanical evolution 

分 类 号：TM910.4[电气工程—电力电子与电力传动]