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

Abstract

LiNi_0.5Mn_1.5O₄ 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 LiNi_0.5Mn_1.5O₄ materials. Cyclic voltammograms and charge–discharge curves were obtained for presenting the electrochemical performances of LiNi_0.5Mn_1.5O₄. Experimental results show that the discharge capacity and capacity retention of the LiNi_0.5Mn_1.5O₄ prepared by solution evaporation process are superior to the LiNi_0.5Mn_1.5O₄ obtained by melting salt method. The effects of different sintering temperatures on the electrochemical properties of the LiNi_0.5Mn_1.5O₄ electrode materials synthesized by a solution evaporation process were also systematically investigated. With the raising of the sintering temperature, the size of the LiNi_0.5Mn_1.5O₄ gradually increases, its crystallinity is enhanced and the surface morphology of grain is gradually neatened. Electrochemical test results show that the LiNi_0.5Mn_1.5O₄ prepared at 800 °C has the best cycle reversibility, the highest discharge capacity and the optimal capacity retention.