Structural, electrochemical and cycling properties of Nb⁵⁺ doped LiNi_0.8Co_0.1Mn_0.1O₂ cathode materials at different calcination temperatures for lithium-ion batteries

Abstract

LiNi_0.8Co_0.1Mn_0.1O₂ cathode material is prepared by sol-gel method and the effects of Nb⁵⁺ doping and different calcination temperatures on cathode materials were deeply investigated. Structural and morphological characterizations revealed that the optimal content of 1 mol% Nb⁵⁺ can stabilize layered structures, mitigate Ni²⁺ migration to Li layers, improve lithium diffusion capacity, and reduce lattice expansion/shrinkage while cycling. And calcination temperature at 800 °C can not only ensure good morphology, but also suppress the mixed discharge of lithium and nickel in the internal structure. Electrochemical performance evaluation revealed that Nb⁵⁺ doping improves the discharge-specific capacity of the material, which is conducive to ameliorating its rate capability and cycle performance. And the material at 800 °C exhibits the highest discharge specific capacity, the best magnification performance, low polarizability, and the best cycle reversibility.