Effects of Mn3O4 particle size and tap density on the electrochemical performance of LiMn2O4 cathode materials

To address the problem of rapid capacity decay of LiMn2O4 during the cycling process, Mn3O4 with different particle sizes and tap densities was prepared by manganese salt method, and used as a precursor to synthesize LiMn2O4 cathode material. The effects of Mn3O4 particle size and tap density on the electrochemical performance were investigated using X-ray diffraction, cyclic voltammetry, electrochemical impedance spectroscopy, and galvanostatic charge-discharge tests. The results indicate that increasing the particle size of the Mn3O4 precursor leads to a slight decrease in the initial discharge specific capacity, but significantly improves both cycling stability and rate performance. Compared with the material derived from 6 μm Mn3O4, the cathode material prepared from 10 μm Mn3O4 exhibits a 6.2% reduction in initial discharge capacity, while achieving an 8.0% increase in capacity retention after 300 cycles and a 25.2% improvement at 5 C. Moreover, when the tap density of Mn3O4 exceeds 2.5 g/cm3, the rate performance of the material deteriorates sharply. The LiMn2O4 sample prepared with a precursor particle size of 10 μm and tap density of 2.5 g/cm3 demonstrates the best overall electrochemical performance, delivering discharge specific capacities of 122.48, 111.9, and 78.42 mAh/g at 0.1, 1, and 5 C, respectively, along with a capacity retention of 90.3% after 300 cycles. This study clarifies the influence of precursor physical properties on the electrochemical properties of LiMn2O4, providing basis for the synthesis of high-performance LiMn2O4 materials.