Effect of Ni and Cu substitution on the crystal structure, morphology and electrochemical performance of spinel LiMn2O4

Abstract

Ni and Cu bi-metal doping of spinel LiMn2O4 materials are investigated by characterizing the as prepared materials by XRD, FTIR, SEM, TEM, CV, Charge/discharge measurements and electrochemial impedance spectroscopy (EIS). Although, Ni and Cu doping decreased the initial discharge capacity, the optimized composition such as LiNi0.01Cu0.01Mn1.98O4 demonstrates good capacity retention after prolonged charge/discharge cycling and high rate capability. The observed enhanced electrochemical performance of Ni-Cu bi-metal doped samples may be attributed to the suppression of the strucutral changes along with improved lithium-ion kinetics during charge/discharge process.