Boosting the electrochemical performance of LiNi0.6Mn0.2Co0.2O2 through a trace amount of Mg-B co-do

• 作 者: Ning Zhang Ying Li Yifan Qiao
• 机 构: School of Metallurgy,Northeastern University,Shenyang 110819,China;Liaoning Key Laboratory for Metal
• 出 处: 材料科学技术（英文版）
• 发表日期: 2021年30期
• 关键词: High-nickel cathode Mg doping B doping Mg-B co-doping Electrochemical performanc

The extended cycle life of cells is often sacrificed at the expense of high specific energy for high-nickel materials.Cation doping is a promising method to build high-nickel cathode with high energy density and long cycle life.Herein,a trace amount of Mg-B co-doping in LiNi0.6Mn02Co0.2O2 (NMC622) is investigated in this work,which shows improved structural and electrochemical stability of 1％ Mg-0.5 ％ B co-doped material at both 30 and 55 ℃ in coin-cell.Comprehensive chemical composition,structural,and surface analysis are carried out in this paper.It was found that all the selected materials have a similar compo-sition to the target.Moreover,Mg and B doping have different effects on the crystal structural change of NMC622,to be more specific,the c-lattice parameter increases with Mg doping,while the Li+/Ni2+mixing content increases when B was incorporated into the lattice.Furthermore,the microstructure of primary particles was changed by B doping significantly as confirmed by the SEM images.There were marginal benefits in terms of structural and electrochemical stability of materials introduced by Mg or B sole doping.In comparison,incorporating a suitable amount of both Mg and B into NMC622,we found the capacity retention of cells was noticeably improved by reducing the impedance growth and preventing cation mixing during cycling.This study demonstrates the importance of co-incorporation of Mg,B,and optimizing the co-dopant content to stabilize NMC622 as cathode for lithium-ion batteries.