电池级磷酸铁的制备及性能

以铁粉和H₃PO₄为原料，采用沉淀法制备了FePO₄，并研究了反应温度、反应时间、过氧化氢加入量对FePO₄性能的影响。利用X射线衍射分析仪、扫描电子显微镜、激光粒度分析仪、TG/DTA和电感耦合等离子体发射光谱仪等对制备的磷酸铁形貌、晶体结构与化学成分进行了表征。实验结果表明，磷酸铁制备过程的最佳实验条件为：反应温度70℃，反应时间1h，H₂O₂过量10%滴加时间60min。在最佳条件下制备的磷酸铁粒径为1~4μm，结晶度好，纯度高。样品中铁的质量分数为36.37%，磷的质量分数为20.86%，铁磷物质的量比为0.97，均可达到电池级磷酸铁的标准，完全可以满足磷酸铁锂正极材料前体的要求。

Preparation and performance of FePO4 precursor for LiFePO4

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.