摘要：本次实验研究了一种合成改性无水磷酸铁的方法。铁源利用的是单质铁粉，碳酸锂作为锂源，磷酸用作磷源，即首先将磷酸加入去离子水中配制成磷酸溶液，控制溶液温度50~80℃。在搅拌状态下加入的还原铁粉反应3h后，将所得的前驱液加入纳米砂磨机中，球磨2h获得粒径分布中D50为200~400nm的悬浊液。将获得的球磨悬浊液于喷雾干燥，得到球形前躯体粉体。最后将所得球形前躯体粉体在600~800℃空气气氛中煅烧8h后获得无水的正磷酸铁材料。80910

再用这种自制无水磷酸铁合成磷酸铁锂电池材料制备电池通过电化学性能测试数据客观具说明这种无水磷酸铁合成技术具有研究意义。并通过X射线衍射（XRD）的物相组成、扫描电镜（SEM）的材料形貌特征，通过充放电循环测试、循环伏安法（CV）和阻抗表征合成材料的电化学性能。

实验表明通过这个技术的路线合成，无水FePO4成能够在煅烧温度为750℃下得以实现。得到的无水FePO4材料用来合成磷酸铁锂正极材料是稳定规则的球状样貌，大小均值为4-5μm，这种小粒子具有纳米级别大小的细孔，并且是200nm上下的微型颗粒构成。所得到LiFePO4电池通过20次充放电循环，其首次充放电比容量分别达到152。8mAh/g、144。1mAh/g，放电比容量保持率为90。30%，充电比容量保持率为92。86%。展示出良好的循环稳定性。

毕业论文关键词：磷酸铁锂；纳米 球磨；喷雾干燥；循环稳定性；比容量。

Study on Synthesis Technology of Modified Anhydrous Iron Phosphate

Abstract: This study was conducted to study the synthesis of anhydrous iron phosphate。 Iron source is the use of elemental iron powder, lithium carbonate as a lithium source, phosphoric acid as a phosphorus source, that is, first added to the deionized water phosphoric acid solution prepared by the control solution temperature 50 ~ 80oC。 After the reaction was carried out for 3 hours after the addition of the reduced iron powder, the resulting precursor liquid was added to a nano-sand mill, and a suspension having a D50 of 200 to 400 nm in the particle size distribution was obtained by ball milling for 2 hours。 The obtained ball mill suspension was spray dried to obtain a spherical precursor powder。 Finally, the obtained spherical precursor powder was calcined at 600 ~ 800 ℃ for 8h to obtain anhydrous calcium orthophosphate material。

And then use this homemade anhydrous iron phosphate synthesis of lithium iron phosphate material prepared by the electrochemical performance test data objective to illustrate this anhydrous iron phosphate synthesis technology has a research significance

The electrochemical properties of the composites were characterized by X - ray diffraction (XRD) and scanning electron microscopy (SEM)。 The electrochemical properties of the composites were characterized by charge - discharge cycle test, cyclic voltammetry (CV) and impedance。

Experiments show that through the synthesis of this technology route, anhydrous FePO4 into the calcination temperature can be achieved at 750 ℃。 The obtained anhydrous FePO4 material is used to synthesize the lithium iron phosphate cathode material as a stable regular spherical shape with a size uniformity of 4-5μm。 This small particle has nano-sized pores and is a micro-particle of 200nm up and down constitute。 The discharge capacity of the LiFePO4 battery was 152。8mAh / g, 144。1mAh / g, the specific capacity of the discharge was 90。30% and the charge capacity was 92。86%。 Showing good cycle stability。

Key words: lithium iron phosphate; nano-ball mill; spray drying; cycle stability; specific capacity。

目录

1 绪论 1

1。1 磷酸铁的性质 1

1。2 磷酸铁的应用