Cooperative structure of Li/Ni mixing and stacking faults for achieving high-capacity Co-free Li-rich oxides  

作　　者：Zhen Wu Yu-Han Zhang Hao Wang Zewen Liu Xudong Zhang Xin Dai Kunyang Zou Xiaoming Lou Xuechen Hu Lijing Ma Yan Liu Yongning Liu 

机构地区：[1]State Key Laboratory for Mechanical Behavior of Materials,Xi’an Jiaotong University,Xi’an 710049,Shaanxi,China [2]Qingdao Industrial Energy Storage Research Institute,Qingdao Institute of Bioenergy and Bioprocess Technology,Chinese Academy of Sciences,Qingdao 266101,Shandong,China [3]Hefei Advanced Computing Center Operation Management Corp Ltd,Hefei 230088,Anhui,China [4]Center for High Performance Computing,Network Information Center,Xi’an Jiaotong University,Xi’an 710049,Shaanxi,China [5]Wuhan Dongfeng Motor Corporation Ltd,Wuhan 430056,Hubei,China [6]School of Materials Science and Intelligent Engineering,Nanjing University,Suzhou 215163,Jiangsu,China [7]Key Laboratory of MEMS of the Ministry of Education,Southeast University,Nanjing 210096,Jiangsu,China [8]International Research Center for Renewable Energy State Key Laboratory of Multiphase Flow in Power Engineering,Xi’an Jiaotong University,Xi’an 710049,Shaanxi,China

出　　处：《Journal of Energy Chemistry》2024年第8期315-324,I0007,共11页能源化学（英文版）

基　　金：financially supported by the National Natural Science Foundation of China(52202046,51602246,and 51801144);the Natural Science Foundation of Shanxi Provincial(2021JQ-034)。

摘　　要：Co-free Li-rich layered oxides(LLOs)are emerging as promising cathode materials for Li-ion batteries due to their low cost and high capacity.However,they commonly face severe structural instability and poor electrochemical activity,leading to diminished capacity and voltage performance.Herein,we introduce a Co-free LLO,Li_(1.167)Ni_(0.222)Mn_(0.611)O_(2)(Cf-L1),which features a cooperative structure of Li/Ni mixing and stacking faults.This structure regulates the crystal and electronic structures,resulting in a higher discharge capacity of 300.6 mA h g^(-1)and enhanced rate capability compared to the typical Co-free LLO,Li_(1.2)Ni_(0.2)Mn_(0.6)O_(2)(Cf-Ls).Density functional theory(DFT)indicates that Li/Ni mixing in LLOs leads to increased Li-O-Li configurations and higher anionic redox activities,while stacking faults further optimize the electronic interactions of transition metal(TM)3d and non-bonding O 2p orbitals.Moreover,stacking faults accommodate lattice strain,improving electrochemical reversibility during charge/discharge cycles,as demonstrated by the in situ XRD of Cf-L1 showing less lattice evolution than Cf-Ls.This study offers a structured approach to developing Co-free LLOs with enhanced capacity,voltage,rate capability,and cyclability,significantly impacting the advancement of the next-generation Li-ion batteries.

关 键 词：Co-free Li-rich oxides Li/Ni mixing Stacking faults Electronic structure 

分 类 号：TM912[电气工程—电力电子与电力传动]