摘要
分别以蔗糖、柠檬酸、酒石酸为碳源,采用高温固相法制备了LiFePO4/C正极复合材料.利用X-射线衍射(XRD)、热重差热分析(TGA)、扫描电子显微镜(SEM)、拉曼光谱(Raman)、充放电测试、循环伏安及交流阻抗测试系统研究了不同碳源包覆对材料微结构及电化学性能的影响.XRD结果表明合成的材料均具有单一的橄榄石型结构;热重差热分析表明3个样品的质量度分数均为7%.SEM结果发现以蔗糖为碳源的LiFePO4/C团聚现象严重,以柠檬酸为碳源的LiFePO4/C颗粒最大,以酒石酸为碳源的LiFePO4/C颗粒最小.Raman表明以蔗糖或酒石酸为碳源的LiFePO4/C具有很好的石墨化碳.电化学性能表明以酒石酸为碳源的LiFePO4/C具有最佳的倍率和循环性能.
Olivine LiFePO4/C cathode materials were successfully prepared by solid state reac- tion with different carbon source （sucrose, citric acid and tartaric acid）, and the effect of carbon source on the structure and the electrochemical performances were systematically investigated by XRD, TGA, SEM, Raman, charge-discharge test, cyclic vohammetry （CV）, and AC imped- ance. Analysis from XRD results show that all-prepared powers can be indexed to be a single-phase of an orthorhombic olivine-type structure. Thermogravimetrie analysis （TGA） reveals that the carbon content in every sample is about 7%. More particle agglomeration is found in LiFePO4/C using su- crose as carbon source, LiFePO4/C using citric acid as carbon source has largest particle-size while LiFePOJC using tartaric acid as carbon source has smallest particle-size. Raman spectra demon- strate LiFePO4/C using sucrose or tartaric acid as carbon source has well-graphitized carbon. Analy- sis from the electrochemical measurements indicate that LiFePO4/C prepared by tartaric acid shows best electrochemical performances.
出处
《福建师范大学学报（自然科学版）》
CAS
CSCD
北大核心
2014年第3期47-52,共6页
Journal of Fujian Normal University：Natural Science Edition
基金
国家973计划项目(2011CBA00200)
国家自然科学基金资助项目(11344008)
福建省自然科学基金资助项目(2013J01007)
