Effect of spray drying technological conditions on the performance of LiFePO4/C cathode materials with high energy density

Abstract

Lithium iron phosphate/carbon (LiFePO4/C) composites with high energy density were synthesized by wet ball milling, spray drying, and carbothermal reduction method. The effect of spray drying technological conditions on the performance of LiFePO4/C composites was systematically investigated. The samples were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), electrochemical impedance spectroscopy (EIS), and galvanostatic charge/discharge tests, etc. The results show that all as-prepared LiFePO4/C composites have a well-ordered olivine structure and spherical morphology. Compared with centrifugal spray drying technology, LiFePO4/C prepared by pressure spray has a smaller particle size and exhibits more uniform particle size distribution as well as better electrochemical performance. However, as the particle size of LiFePO4/C microspheres is decreased, the sphericity of particles becomes worse and tap density of materials steps down, resulting in poor processability in 14500 cylindrical battery.