Effects of α-Fe2O3 size and morphology on performance of LiFePO4/C cathodes for Li-ion batteries

In this study, carbon-coated lithium iron phosphate (LiFePO4/C, denoted as LFP/C) composite cathode materials were prepared through wet ball milling and spray drying. Ground and spherical α-Fe2O3 precursors were used to synthesize LFP samples. Wet ball milling and a solvothermal method were used to prepare α-Fe2O3 particles with a smaller size and spherical morphology, respectively. The as-prepared α-Fe2O3 was used to synthesize LFP/C composites in order to investigate the effects of α-Fe2O3 size and morphology on the electrochemical performance of LFP/C cathode materials. Charge-discharge measurements revealed that the LFP/C cathode materials prepared from the ground and spherical α-Fe2O3 precursors delivered a similar specific discharge capacity of approximately 150 mAh/g at 0.1 C and 96 mAh/g at 10 C, which was higher than that of the LFP/C cathode materials prepared using the irregular and unground α-Fe2O3 (the discharge capacity was 135 mAh/g at 0.1 C and 62 mAh/g at 10 C). The results reveal that the size and morphology of iron precursors have a profound influence on the electrochemical properties of LFP/C materials. The results obtained in this study can serve as a reference in the use of the solid-state method to produce low-cost LFP/C cathode materials with favorable consistent properties and high electrochemical performance.