“绣球”状中空C/Nb2O5微球的制备及其电化学性能研究  

Preparation and Electrochemical Performance of Hydrangea Like Hollow C/Nb2O5 Microspheres

作　　者：周伟 吴泽斌 曾癸霖 郑佳玲 ZHOU Wei;WU Zebin;ZENG Guilin;ZHENG Jialing(College of Metallurgy and Material Engineering,Hunan University of Technology,Zhuzhou Hunan 412007,China)

机构地区：[1]湖南工业大学冶金与材料工程学院,湖南株洲412007

出　　处：《湖南工业大学学报》2021年第1期76-83,共8页Journal of Hunan University of Technology

基　　金：国家自然科学基金资助项目(51604107);湖南省自然科学基金资助项目(2019JJ50115)。

摘　　要：以草酸铌为铌源,空心碳球为模板,采用简单的水热法合成了具有独特形貌的“绣球”状中空C/Nb2O5微球。采用X射线衍射(XRD)、扫描电子显微镜(SEM)和透射电子显微镜(TEM)表征了所制备中空C/Nb2O5微球的微观结构,并采用电化学工作站研究了其作为负极材料的锂离子电池的电化学性能。研究结果表明,直径约为1μm的空心碳球被Nb2O5包覆,中空C/Nb2O5微球呈现出独特的“绣球”形状,使其比表面积明显增大;在电流密度为40 mA/g下,中空C/Nb2O5微球和Nb2O5微球作为负极材料的锂离子电池的初始放电比容量分别为402.26 mA·h/g和336.44 mA·h/g,经过50次充放电循环后,当电流密度返回40 mA/g时,中空C/Nb2O5微球的放电容量为192.38 mA·h/g,而Nb2O5微球的放电容量仅为4.86 mA·h/g。说明这种特殊的“绣球”状中空结构有效地增加了Nb2O5的表面积,并使得中空C/Nb2O5微球负极材料具有高的比容量和良好的可逆性能。With niobium oxalate as the niobium source and hollow carbon sphere as a template,a synthesis can be achieved of hollow C/Nb2O5 microspheres with unique morphology by adopting a simple hydrothermal method,followed by an investigation made of the microstructure of as-prepared C/Nb2O5 microspheres by X-ray diffraction(XRD),scanning electron microscopy(SEM),and transmission electron microscopy(TEM).The results show that the hollow carbon spheres with a diameter of about 1μm are coated with Nb2O5,and the hollow C/Nb2O5 microspheres are characterized with a unique“hydrangea”shape leading to a significant increase of the specific surface area.The initial discharge specific capacity of the C/Nb2O5 microspheres and Nb2O5 microspheres at a current density of 40 mA/g is 402.26 mA·h/g and 336.44 mA·h/g,respectively.After 50 cycles,the discharge capacity of the C/Nb2O5 microspheres is maintained at 192.38 mA·h/g,with the discharge capacity of Nb2O5 microspheres being only 4.86 mA·h/g.The results show that the special“hydrangea”hollow structure can effectively increase the surface area of Nb2O5,thus enabling the hollow C/Nb2O5 microsphere anode material to be characterized with a high specific capacity and good reversible performance.

关 键 词：锂离子电池 绣球状 C/Nb2O5微球 水热法 

分 类 号：TM911.15[电气工程—电力电子与电力传动]