前驱体二水磷酸铁对磷酸铁锂电化学性能的影响  

Effect of precursor FePO_4·2H_2O on electrochemical properties of LiFePO_4

作　　者：张军[1] 刘恒[1] 王燕[2] 钟本和[3] 高超[1] 王巍[1] 李建龙[1] 

机构地区：[1]四川大学材料科学与工程学院,四川成都610064 [2]西南民族大学计算机科学与技术学院 [3]四川大学化学工程学院

出　　处：《无机盐工业》2013年第4期60-62,共3页Inorganic Chemicals Industry

摘　　要：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。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 par- ticle 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.

关 键 词：磷酸铁 磷酸铁锂 锂离子电池 正极材料 

分 类 号：TQ131.11[化学工程—无机化工]