Extremely rapid synthesis of disordered LiNi0.5Mn1.5O4 with excellent electrochemical performance

Abstract

Single phase LiNi0.5Mn1.5O4 spinel with excellent electrochemical performance has been synthesized by a novel solution combustion synthesis method at 700°C for 30min. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and scanning electron microscope (SEM) have been used to investigate the phase structure and micro-morphology of the product. Charge–discharge measurement, cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) have been used to study the electrochemical performance. The results indicate that the as-prepared product is a single phase LiNi0.5Mn1.5O4 spinel with a disordered Fd−3m space group. The LiNi0.5Mn1.5O4 exhibits excellent electrochemical performance including cycling stability and rate capability due to its high cystallinity, large Li+ diffusion coefficient and low charge transfer resistance. It can deliver reversible capacities of 130, 113 and 104mAh/g at 1C, 10C and 20C current rates, respectively. The capacity retentions of the product at 1C at room temperature, at 10C at room temperature and at 1C at 55°C after 100 cycles are 97.5%, 99.7% and 94.2%, respectively.