乙醇-水体系3D纳/微米球形磷酸铁的制备与表征

提出了一种在温和条件下制备高振实密度球形磷酸铁的简单方法。制备过程中无需引入碱性物质调节pH和添加其他模板剂,仅以九水合硝酸铁Fe（NO₃）·9H₂O]和磷酸（H₃PO₄）为原料,在乙醇-水体系中即可制备3D纳/微米球形磷酸铁（记为FPE）。采用扫描电镜（SEM）、激光粒度仪、X射线衍射仪（XRD）、热重-差式扫描量热仪（TG-DSC）、比表面积测试仪（BET）等对制备的磷酸铁进行表征分析。结果显示,制备的磷酸铁具有3D纳/微米球形结构,平均一次粒径为27.2 nm,二次粒径D₅₀为3.75 μm。FPE的组成为二水合磷酸铁（FePO₄·2H₂O）,纯度较高,具有介孔结构,平均孔径为2.75 nm,比表面积为22.41 cm ²/g,同时具有较高的振实密度（1.34 g/cm ³）。3D纳/微米球形磷酸铁制备方法简单,性能优异,以其为前驱体制备的磷酸铁锂（LiFePO₄/C）具有较高的振实密度（1.46 g/cm ³）,在0.2C倍率下的放电比容量为157.9 mA·h/g。

Synthesis and characterization of 3D nano/micro spherical iron phosphate in ethanol-water system

A simple method for preparing high tap density spherical iron phosphate under mild conditions was proposed.Iron phosphate with 3D nano/micro spherical structure（FPE） was prepared by using ferric nitrateFe（NO₃）·9H₂O] and phospho-ric acid（H₃PO₄） as raw materials in a mixed solution of ethanol and water without introducing alkaline substances for pH ad-justing and other templating agents.The obtained products were characterized by SEM,laser particle size analyzer,XRD,TG-DSC and BET.The results indicated that the iron phosphate prepared by this method had a 3D nano/micro spherical struc-ture,an average primary particle diameter of 27 nm and a secondary particle diameter D₅₀ of 3.75 μm.The composition of FPE was iron phosphate dihydrate FePO₄·2H₂O with high purity.The FPE had a mesoporous structure with average pore diameter of 2.75 nm,specific surface area of 22.41 cm ²/g and high tap density of 1.34 g/cm ³,3D nano/micro spherical iron phosphate is simple to prepare and has excellent performance.The lithium iron phosphate LiFePO₄/C prepared by using the precursor FPE has a high tap density of 1.46 g/cm ³,and the discharge capacity is 157.9 mA·h/g at 0.2C.