快速沉淀-碳热还原法合成亚微米LiFePO_4/C  

Submicro LiFePO_4/C prepared by fast precipitation-carbothermal reduction method

作　　者：彭忠东[1] 裴振兴[1] 石迪辉 胡国荣[1] 

机构地区：[1]中南大学冶金科学与工程学院,湖南长沙410083 [2]临沂杰能新能源材料有限公司,山东临沂276023

出　　处：《电池》2013年第5期257-260,共4页Battery Bimonthly

摘　　要：以FeSO4·7H2O、NH4H2PO4和H2O2为原料，用快速沉淀法制备亚微米无定形FePO4·2H2O，再将FePO4·2H2O、Li2CO3和葡萄糖球磨混合，通过碳热还原法合成LiFePO4／C复合材料。通过XRD、SEM和TEM分析及充放电测试考察了反应物浓度和反应温度对FePO4·2H2O的影响。当溶液浓度为0．2mol／L、反应温度为50℃时，可制备形貌一致、粒度分布均匀且纯度高的亚微米无定形FePO4·2H2O。合成的LiFePO4／C粒度分布均匀，碳包覆膜完整，在2．5—4．1V充放电，1．0C和2．0C首次放电比容量分别为140．5mAh／g和134．9mAh／g，循环100次的容量保持率分别为100．0％和97．8％。Submiero amorphous FePO4 ·2H2O was prepared by fast precipitation method using FeSO4·7H2 O, NH4 H2PO4 and H2O2 as raw materials ,LiFePO4/C composite was synthesized by carbothermal reduction method with the homogeneous mixture of FePO4· 2H2O,Li2CO3 and glucose. The effects of reagent concentration and reaction temperature to FePO4 .2H20 were investigated by XRD, SEM and TEM analyses and charge-discharge test. Submiero amorphous FePO4 ·2H20 synthesized with solution concentration of 0. 2 mol/L and reaction temperature at 50 ℃ had the same morphology, uniform particle size distribution and high purity. LiFePO,/C composite as prepared had uniform particle size distribution, complete carbon coating, when charged-discharged in 2.5 - 4. 1 V,its 1.0 C and 2.0 C initial specific discharge capacity was 140.5 mAh/g and 134. 9 mAh/g, respectively, the capacity retention rate in the 100th cycle was 100. 0% and 97. 8% ,respectively.

关 键 词：正极材料 快速沉淀 磷酸铁(FePO4) 磷酸铁锂(LiFePO4) 

分 类 号：TM912.9[电气工程—电力电子与电力传动]