Effect of Magnesium Substitution on Electrochemical Performances of Layered LiNiO₂ Cathode Materials

Ni-rich layered oxides are receiving increased attention as cathodes due to their high energy density. However, the gradual structural transformation during charging/discharging will lead to capacity degradation. The introduction of pillar elements into the Li slab is beneficial for the lattice stability and cycle performance. Herein, atomic configuration, electronic structure, and electrochemical redox behavior of a Mg-doped LiNiO₂ cathode were studied. Analysis of the calculations shows that Mg doping can significantly improve the cycle performance and electronic conductivity, but suppresses the Li mobility to a certain extent in the cathode. The theoretical study gives an insight into the microscopic mechanism of Mg doping to improve the performance of Ni-rich cathode material, which is a necessary supplement to the experimental research.