关键词: 铁粉, 磷酸铁前体, 磷酸铁锂正极材料, 锂离子电池, 颗粒物料, 沉淀

Abstract:

Battery-grade iron phosphate was prepared by precipitation method using iron powder and phosphoric acid as raw materials. The effects of reaction temperature, reaction time and the amount of hydrogen peroxide on the quality of the produced iron phosphate were explored. The crystal morphology, structure and chemical composition of the prepared iron(Ⅲ) phosphate were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), laser particle size analysis, thermal gravimetric analysis (TG/DTA) and inductively coupled plasma atomic emission spectrometer (ICP-AES). Experimental results showed that the optimal experimental parameters were: reaction temperature of 70℃, reaction time of 1h, 10% excess of H₂O₂, H₂O₂ dropping time of 60 minutes. The particle size of iron phosphate prepared under the optimum conditions was 1—4μm, with good crystallinity and high purity. The iron and phosphorus content test showed that the iron content of the sample was 36.37%, the phosphorus content was 20.86%, and the molar ratio of iron to phosphorus was 0.97, satisfying the requirements of battery grade of FePO₄ precursor and lithium iron phosphate anode material precursor.

Key words: iron powder, iron phosphate precursor, lithium iron phosphate cathode material, lithium-ion battery, granular materials, precipitation