Abstract
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.
基金项目
National Natural Science Foundation of China(numbers.51834004)
National Natural Science Foundation of China(51774076)
National Natural Science Foundation of China(51704062)
Fundamental Research Funds for the Central Universities(N2025019)
NETL
NSTL
万方数据