Effect of Calcining Temperatures on the Electrochemical Performances of LiNi0.5Co0.2Mn0.3O2 Cathode Material for Lithium Ion Batteries

Abstract

In this paper, the effects of calcination temperatures on the electrochemical properties of LiNi0.5Co0.2Mn0.3O2 cathode materials for lithium ion batteries were studied. The LiNi0.5Co0.2Mn0.3O2 materials were prepared by a sol-gel method at 750 oC, 800 oC, 850 oC and 900 oC, respectively. In order to study the effects of calcination temperatures on the material, X-ray diffraction, scanning electron microscope, charge/discharge cycle test, cyclic voltammetry test and impedance test were used to characterize and test the materials. The results show that with the increase of calcination temperature, the particles of LiNi0.5Co0.2Mn0.3O2 materials change from spherical to regular polyhedron. The LiNi0.5Co0.2Mn0.3O2 material prepared at higher calcination temperature has better electrochemical properties, but too high calcination temperature will also have adverse effects on the properties of the materials. When the calcination temperature is 850 oC, the particle size of LiNi0.5Co0.2Mn0.3O2 material is uniform with good dispersion, high crystallinity and good layered structure. And also it has the best electrochemical performance. The first discharge specific capacity of the material prepared at this calcination temperature is 168.3mAh g-1 with a retention rate is 90.4% after 50 cycles.