Synthesis mechanism and characterization of LiMn0.5Fe0.5PO4/C composite cathode material for lithium-ion batteries

In this study, the solid-phase synthesis mechanism of LiMn0.5Fe0.5PO4 is first studied, and the decomposition characteristics of each reactant are analyzed. It is found that the raw materials decompose first and then the desired cathode material is synthesized. The synthesized LiMn0.5Fe0.5PO4 is pretreated by the ultrasonic dispersion and then the LiMn0.5Fe0.5PO4/C particles with better morphology and performance are obtained with carbon coating. The structure, morphology and electrochemical properties of LiMn0.5Fe0.5PO4/C composite cathode material are analyzed. The synthesized LiMn0.5Fe0.5PO4/C sample has an olivine crystal phase, and the particles are spherical with an average size of approximately 200 nm. The galvanostatic charge-discharge test shows that the specific capacity of this material is 141 mAh·g−1 at 0.1C, and its apparent conductivity reaches 2.317 × 10−5 S/cm, explaining its excellent rate performance. The preparation method in this study provides valuable guidance for the industrial production of LiMn0.5Fe0.5PO4/C cathode materials. •Synthesis mechanism of LiMn0.5Fe0.5PO4 is systematically researched and analyzed.•The material is firstly decomposed and then synthesized into the desired product.•The uniformity of carbon coating is significantly improved by ultrasonic dispersion.•Low raw material cost, and no pollution gas is generated during preparation.