微波CVD法制备磷酸铁锂 2f炭纤维复合正极材料.pdfVIP

D6 微波 CVD 法制备磷酸铁锂/炭纤维复合正极材料 邓飞 1 曾燮榕2, 3 邹继兆 2, 3 黎晓华 2, 3 熊信柏2, 3 钱海霞 2, 3 （1.西北工业大学材料学院，西安 710072 ；2.深圳大学材料学院，深圳 518060； 3. 深圳市特种功能材料重点实验室，深圳 518060 ） 摘要：本文采用微波 CVD 法制备了磷酸铁锂/气相生长炭纤维（VGCFs ）复合正极材料。借助X 射线衍射仪、场发射扫描电子显微镜和电化学测试仪研究了不同温度下制备材料的结构和电化 学性能。结果表明，当温度低于 600℃时，由于 VGCFs 导电网络的逐渐形成，材料的放电比容 量随着温度的提高而增加；但当温度进一步升高时，由于磷酸铁锂的晶粒异常长大，锂离子的 扩散距离增加，反而导致材料的放电比容量降低。研究发现，当温度为 600℃时，材料表现出较 优的电化学性能，在 25 ℃于 0.5C 倍率放电时的比容量可达 148mAh/g，且具有良好的循环保持 能力。 关键词：磷酸铁锂; 气相生长炭纤维；微波化学气相沉积；锂离子电池 LiFePO /vapor-grown carbon fibers composite cathode 4 materials prepared by microwave chemical vapor deposition process 1 2, 3 2, 3 2, 3 Fei DENG , Xierong ZENG , Jizhao ZOU , Xiaohua LI , Xinbo XIONG2, 3, Haixia QIAN2, 3 (1. School of Materials Science and Engineering, Northwestern Polytechnical University, Xi’an, 710072 ,China ；2. College of Materials Science and Engineering, Shenzhen University, Shenzhen, 518060 ,China ；3. Shenzhen Key Laboratory of Special Functional Materials, Shenzhen, 518060 ,China) Abstract: LiFePO /Vapor-grown carbon fibers (VGCFs) composite cathode materials 4 were prepared by microwave chemical vapor deposition at a temperature ranging from 550 ℃to 700 ℃ . The phase, microstructure and electrochemical performance of the composite electrodes were investigated. Results show that the temperature has an important effect on the structure and performance of the composites. With the increasing of temperature (＜600℃), the rate capabilities of the composite cathodes are improved because of the gradual formation of conductive network of VGCFs. However, it