Improving structure stability of single-crystalline Ni-rich cathode at high voltage by element gradient doping and interfacial modifcation  

作　　者：Ruijuan Wang Yixu Zhang Zhi Li Lei Wu Jiarui Chen Xiaolin Liu Hui Hu Hao Ding Shuang Cao Qiliang Wei Xianyou Wang 

机构地区：[1]National Base for International Science&Technology Cooperation of New Energy Equipment,Energy Storage Materials and Devices,National Local Joint Engineering Laboratory for Key Materials of New Energy Storage Battery,Hunan Province Key Laboratory of Electrochemical Energy Storage&Conversion,School of Chemistry,Xiangtan University,Xiangtan 411105,Hunan,China [2]Institute of Micro/Nano Materials and Devices,Ningbo University of Technology,Ningbo 315211,Zhejiang,China

出　　处：《Journal of Energy Chemistry》2025年第2期630-640,I0013,共12页能源化学(英文版)

基　　金：supported by the National Natural Science Foundation of China(U19A2018);the Natural Science Foundation of Hunan Province(2021JJ30651);the Postgraduate Scientific Research Innovation Project of Hunan Province(CX20230643).

摘　　要：Single-crystalline Ni-rich cathodes can provide high energy density and capacity retention rates for lithium-ion batteries(LIBs).However,single-crystalline Ni-rich cathodes experience severe transition metal dissolution,irreversible phase transitions,and reduced structural stability during prolonged cycling at high voltage,which will significantly hinder their practical application.Herein,a Li4TeO5surface coating along with bulk Te-gradient doping strategy is proposed and developed to solve these issues for single-crystalline Ni-rich LiNi_(0.90)Co_(0.05)Mn_(0.05)O_(2)cathode(LTeO-1.0).It has been found that the bulk Te^(6+)gradient doping can lead to the formation of robust Te-O bonds that effectively inhibit H_(2)-H3 phase transformations and reinforce the lattice framework,and the in-situ Li4TeO5coating layer can act as a protective layer that suppresses the parasitic reactions and grain fragmentation.Besides,the modified material exhibits a higher Young's modulus,which will be conducive to maintaining significant structural and electrochemical stability under high-voltage conditions,Especially,the LTeO-1.0 electrode shows the improved Li^(+)diffusion kinetics and thermodynamic stability as well as high capacity retention of 95.83%and 82.12%after 200 cycles at the cut-off voltage of 4.3 and 4,5 V.Therefore,the efficacious dualmodification strategy will definitely contribute to enhancing the structural and electrochemical stability of single-crystalline Ni-rich cathodes and developing their application in LIBs.

关 键 词：Single-crystalline Ni-rich cathode High cut-off voltage Material fragmentation Li_(4)TeO_(5)coating layer Te^(6+)doping 

分 类 号：TM912[电气工程—电力电子与电力传动] O646[理学—物理化学]