添加剂对LiFePO_4/C复合材料的改性研究  

Effects of additives on modification of LiFePO_4 /C composite materials

作　　者：季晶晶[1,2] 杨伟伟[3] 覃晓捷 李玉[1] 王红强[1] 

机构地区：[1]广西师范大学化学化工学院,广西桂林541004 [2]中国科学院宁波材料技术与工程研究所,浙江宁波315200 [3]南京大学现代工程与应用科学学院,江苏南京210000 [4]广西冶金研究院,广西南宁530000

出　　处：《电源技术》2013年第12期2120-2122,共3页Chinese Journal of Power Sources

基　　金：国家自然科学基金(21063003;51064004);广西科学研究与技术开发计划(桂科攻1099081-1;1114019-3);广西自然科学基金(2011GXNSFA018016)

摘　　要：通过在前驱体浆料中加入聚乙二醇(PEG-6000)、聚乙二醇辛基苯基醚(Triton X-100)和钛酸酯偶联剂(TC-Wt)等不同类型的添加剂,对利用固-液流变相法合成的LiFePO4/C复合材料进一步改性。利用X射线衍射仪和扫描电子显微镜对LiFePO4/C复合材料的结构和形貌进行了表征,利用电化学测试系统对材料的电化学性能进行测试。结果表明:加入三种不同添加剂的LiFePO4/C复合材料团聚减少,颗粒变细,添加了TC-Wt合成的样品粒径最小。添加了PEG-6000,Triton X-100和TC-Wt合成的样品在1 C时的放电比容量分别为133.5,137.6,140.6 mAh/g,5 C时的放电比容量分别为101.5,111.3,127.6 mAh/g,空白样的比容量均低于加入三种不同添加剂的样品,在1 C和5 C时分别为129.8和99.6 mAh/g。LiFePO,/C synthesized by solid-liquid fluid phase method, was modified by adding three different additives of polyethylene glycol （PEG-6000）, octyl polyethylene glycol phenyl ether （Triton X-100） and titanate coupling agent TC-Wt to precursor slurry. The structure and morphology of the LiFePO,/C ball composite materials were characterized by X-ray diffraction （XRD） and scanning electron microscopy （SEM）. The electrochemical performance of material was tested by electrochemical test system. The reunion of the LiFePO4/C composite materials with three additives weakens obviously and the size of particles is refined. Comparing with the other samples, the material with TC-WT obtained the minimum particle size. The initial discharge specific capacities of the samples adding PEG-6000, Triton X-100, and TC-Wt are 133.5, 137.6, 140.6 mAh/g at 1 Cand 101.5, 111.3,127.6 mAh/g at 5 C, respectively. Comparing with the other samples adding three different additives, the specific capacities of the bank sample lower than others are 129.8 and 99.6 mAh/g.

关 键 词：磷酸铁锂 正极材料 固-液流变相法 添加剂 

分 类 号：TM912[电气工程—电力电子与电力传动]