Mg/Fe site-specific dual-doping to boost the performance of cobalt-free nickle-rich layered oxide cathode for high-energy lithium-ion batteries  

作　　者：Yunting Wang Gaohui Du Di Han Wenhao Shi Jiahao Deng Huayu Li Wenqi Zhao Shukai Ding Qingmei Su Bingshe Xu 

机构地区：[1]Materials Institute of Atomic and Molecular Science,Shaanxi University of Science and Technology,Xi'an 710021,Shanxi,China [2]Shanxi-Zheda Institute of Advanced Materials and Chemical Engineering,Taiyuan 030024,Shanxi,China [3]Key Laboratory of Interface Science and Engineering in Advanced Materials,Taiyuan University of Technology,Taiyuan 030024,Shanxi,China

出　　处：《Journal of Energy Chemistry》2024年第4期670-679,共10页能源化学（英文版）

基　　金：the financial supports from the Key Research and Development Project in Shaanxi Province(2023-YBGY-446);the Shanxi-Zheda Institute of Advanced Materials and Chemical Engineering(2022SX-TD003)。

摘　　要：Layer-type LiNi0.9Mn0.1O2is promising to be the primary cathode material for lithium-ion batteries(LIBs)due to its excellent electrochemical performance.Unfortunately,the cathode with high nickel content suffers from severely detrimental structural transformation that causes rapid capacity attenuation.Herein,site-specific dual-doping with Fe and Mg ions is proposed to enhance the structural stability of LiNi0.9Mn0.1O2.The Fe3+dopants are inserted into transition metal sites(3b)and can favorably provide additional redox potential to compensate for charge and enhance the reversibility of anionic redox.The Mg ions are doped into the Li sites(3a)and serve as O_(2)^(-)-Mg^(2+)-O_(2)^(-)pillar to reinforce the electrostatic cohesion between the two adjacent transition-metal layers,which further suppress the cracking and the generation of harmful phase transitions,ultimately improving the cyclability.The theoretical calculations,including Bader charge and crystal orbital Hamilton populations(COHP)analyses,confirm that the doped Fe and Mg can form stable bonds with oxygen and the electrostatic repulsion of O_(2)^(-)-O_(2)^(-)can be effectively suppressed,which effectively mitigates oxygen anion loss at the high delithiation state.This dual-site doping strategy offers new avenues for understanding and regulating the crystalline oxygen redox and demonstrates significant potential for designing high-performance cobalt-free nickel-rich cathodes.

关 键 词：Cobalt-free Layered oxide Cathode Dual dopants Density functional theory calculation 

分 类 号：TM912[电气工程—电力电子与电力传动] TB34[一般工业技术—材料科学与工程]