前驱体二水磷酸铁对磷酸铁锂电化学性能的影响

以钛白生产副产物七水硫酸亚铁为铁源，工业磷酸二氢铵为磷源，双氧水为氧化剂，采用共沉淀法合成了不同粒径和形貌的二水磷酸铁，并以此为前驱体，通过碳热还原法制备了粒径不同的LiFePO₄/C正极材料。经过对样品进行X射线衍射（XRD）、扫描电镜（SEM）以及恒电流充放电测试，研究了二水磷酸铁及LiFePO₄/C的结构、形貌以及电化学性能。结果表明，以较细的二水磷酸铁为铁源，制备得到的LiFePO₄/C颗粒较细，且具有更优异的电化学性能。0.1、0.5、1、2、5、10 C放电比容量分别为154、148、144、140、130、120 mA·h/g。

Effect of precursor FePO4·2H2O on electrochemical properties of LiFePO4

The precursor，FePO₄·2H₂O with different particle sizes and morphologies was syhthesized by co-precipitation method with FeSO₄·7H₂O by-produced from the production of titanium dioxide as the iron source，industrial NH₄H₂PO₄ as the phosphorus source，and with H₂O₂ as the oxidant.LiFePO₄/C cathode material was prepared through carbon thermal reduction technology with as-prepared FePO₄·2H₂O as iron source.The structure，morphology，and electrochemical properties of FePO₄·2H₂O and LiFePO₄/C samples were characterized by XRD，SEM，and galvanostatic charge-discharge tests.Results showed that LiFePO₄/C had much smaller particle size and superior electrochemical performance when the FePO₄·2H₂O with smaller particle size was used as iron source.The initial discharge capacity of the sample was 154，148，144，140，130，120 mA·h/g at 0.1，0.5，1，2，5，10 C rates，respectively.