Preparation of LiNi0.5Mn1.5O4 cathode materials by non-constant temperature calcination and research on its performance

LiNi0.5Mn1.5O4 is a relatively promising high-voltage cathode material for lithium-ion batteries. In order to reduce the preparation cost and energy consumption of LiNi0.5Mn1.5O4, an innovative roasting process — non-constant temperature calcination — was proposed in this paper, and it is characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), laser particle size distribution test, cyclic voltammetry test, electrochemical impedance spectroscopy (EIS), first charge–discharge test, cyclic performance test, and comparative experiment. The research shows that this process avoids the high-temperature and constant-temperature stage, so as to effectively inhibit the growth and agglomeration of material particles, improve the electrochemical performance of the material, and reduce the production energy consumption and cost. It was found through experiments that the optimal heating rate is 2.0 °C/min. At this heating rate, the initial charge–discharge capacity reaches the maximum of 129.6 mAh/g, and the capacity decreases from 126 to 123.5 mAh/g (the capacity retention rate is 98%) after 100 cycles at 1 C.