Mn3O4粒径和振实密度对LiMn2O4正极材料电化学性能的影响OA

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.