Synthesis and electrochemical properties of LiNi0.5Mn1.5O4 as a 5 V cathode material for lithium ion batteries

Abstract

LiNi0.5Mn1.5O4 as a 5 V cathode material for a lithium-ion battery was synthesized by solution evaporation process in this paper. Thermal gravimetric analysis of the precursor compounds was carried out. X-ray diffraction and scanning electron microscope were used for studying the structure and the morphology of the LiNi0.5Mn1.5O4 materials. Cyclic voltammograms and charge–discharge curves were obtained for presenting the electrochemical performances of LiNi0.5Mn1.5O4. Experimental results show that the discharge capacity and capacity retention of the LiNi0.5Mn1.5O4 prepared by solution evaporation process are superior to the LiNi0.5Mn1.5O4 obtained by melting salt method. The effects of different sintering temperatures on the electrochemical properties of the LiNi0.5Mn1.5O4 electrode materials synthesized by a solution evaporation process were also systematically investigated. With the raising of the sintering temperature, the size of the LiNi0.5Mn1.5O4 gradually increases, its crystallinity is enhanced and the surface morphology of grain is gradually neatened. Electrochemical test results show that the LiNi0.5Mn1.5O4 prepared at 800 °C has the best cycle reversibility, the highest discharge capacity and the optimal capacity retention.