Er-doped spinel LiNi0.5Mn1.5O4 as cathode for enhanced electrochemical properties in lithium-ion batteries

LiNi0.5Mn1.5O4 (LNMO) material is a new generation of high-energy density lithium-ion battery (LIB) cathode material, which has attracted the attention of researchers at home and abroad. Due to the inherent side effects of LNMO materials with the electrolyte at high voltage, Mn dissolution is caused, which hinders its application. The pristine and LiNi0.5−x/2Mn1.5−x/2ErxO4 (x = 0.01, 0.03 and 0.05) were prepared by the microwave-assisted sol–gel method as cathode materials for LIBs. XRD diffraction analysis showed that the lattice parameters of LNMO samples increased after Er doping, which broadened the lithium-ion diffusion channel, and FT-IR showed that LiNi0.5−x/2Mn1.5−x/2ErxO4 (x = 0.01) (LNMO-Er0.01) had the largest disorder degree. Based on electrochemical analysis, LNMO materials doped with an adequate amount of Er was found to have superior cycle stability, high temperature, and rate performances. After 200 charge–discharge cycles, the discharge-specific capacity of LNMO-Er0.01 sample is 118.8 mAh g−1, and the capacity retention rate is 93.8