Enhancing the electrochemical performance of single-crystal LiNi0.8Co0.1Mn0.1O2 cathode material by phosphorus doping

Abstract

High nickel ternary cathode materials display high specific capacity and low cost, but still suffer irreversible phase change, side reaction and particle cracking during the electrochemical reaction processes. Herein, a P-doped single crystal Ni-rich cathode material is designed, which shows excellent lithium-ion insertion/extraction capability. The phase transition (H1 → H2 → H3) is relieved by the accumulation of interfacial force due to P-doping, as which increases the charge density and promotes the electrostatic repulsion between oxygen layers. P-doping also leads to an increase of lattice parameter c, and the increased thickness of lithium layers and transition metal layers expands the two-dimensional diffusion channel of lithium-ion in the layered structure, facilitating the lithium-ion insertion/extraction processes. The doped ternary single crystal cathode material demonstrates a stable surface structure with resistance to environmental erosion. This work demonstrates that the P-doping is promising to further improve ternary single crystal cathode material for superior lithium-ion battery applications.