分级结构类球形MgFe_2O_4/C复合材料的制备及其储锂性能  

Synthesis and Li-storage Performance of Hierarchical Spheroid Composites of MgFe_2O_4/C

作　　者：高荣贞 李晓冬[3] 刘文凤 尹艳红 杨书廷[1,2] GAO Rongzhen;LI Xiaodong;LIU Wenfeng;YIN Yanhong;YANG Shuting(National ＆ Local Joint Engineering Laboratory for Motive Power and Key Materials,Xinxiang 453007,China;School of Chemistry and Chemical Engineering,Henan Normal University,Xinxiang 453007,China;College of Chemistry and Chemical Engineering,Luoyang Normal University,Luoyang 471022,China;Henan Battery Research Institute,Xinxiang 453007,China)

机构地区：[1]动力电源及关键材料国家地方联合工程实验室,新乡453007 [2]河南师范大学化学化工学院,新乡453007 [3]洛阳师范学院化学化工学院,洛阳471022 [4]河南电池研究院,新乡453007

出　　处：《材料研究学报》2018年第9期713-720,共8页Chinese Journal of Materials Research

基　　金：国家自然科学基金(21471049)~~

摘　　要：将柠檬酸和Super P (SP)作为碳源用喷雾干燥技术制备出具有分级结构的类球形MgFe_2O_4/C (MFO/C)复合材料,使用场发射扫描电子显微镜(FESEM)、透射电子显微镜(TEM)、X射线粉末衍射仪(XRD)、X射线光电子能谱仪(XPS)和电化学测试等手段表征了样品的形貌、结构和电化学性能。结果表明,在电流密度为0.5 C (500 mA·g^(-1))的条件下这种复合材料的首次放电比容量为1162.7 mAh·g^(-1),200次循环后比容量稳定在约734.5 mAh·g^(-1)。在电流密度为1C (1000 mA·g^(-1))条件下,200次循环后比容量仍保持在约580.4 mAh·g^(-1)。具有优异的循环和倍率性能的原因,可能是SP和柠檬酸分解生成的晶粒间碳形成了良好的导电网络,使材料的导电性提高并缓解了在连续充放电过程中活性物质的团聚和体积膨胀。The spherical composite of MgFe2 O4/C（MFO/C） with hierarchical structure was prepared via spray drying technology with citric acid and Super P（SP） as carbon source. The morphology, structure and electrochemical performance of the MFO/C were characterized by field emission scanning electron microscopy（FESEM）, transmission electron microscopy（TEM）, X-ray powder diffractometer（XRD）,X-ray photoelectron spectrometer（XPS） and electrochemical measurements. Results show that the first discharge capacity of the material is 1162.7 mA·g^（-1） and the reversible specific capacity stabilizes at about 734.5 mA·g^（-1） after 200 cycles when the current density is 0.5 C（500 mA·g^（-1））. Even at a higher current density of 1 C（1000 mA·g^（-1））, the reversible specific capacity stabilizes at about 580.4 mA·g^（-1） after200 cycles. The excellent cycling stability and rate performance can be attributed to the emerging of a su-perior conductive network, which composed of SP and the intergranular carbon formed due to the decomposition of citric acid, as a result, the conductivity of the spherical composite of MgFe2 O4/C could be effectively enhanced, while the aggregation and volumetric expansion of the active particles could also be alleviated in the continuous charge and discharge process.

关 键 词：金属基复合材料 负极材料 喷雾干燥 铁酸镁 锂离子电池 电化学性能 

分 类 号：O646[理学—物理化学] O614.81[理学—化学]