锗酸锌纳米棒@石墨烯复合负极材料的制备及储锂性质  

Zn_2GeO_4 Nanorods@Graphene Composite as Anode Materials for Li-ion Batteries

作　　者：童震坤 方姗[1] 郑浩[1] 张校刚[1] 

机构地区：[1]江苏省能量转换材料与技术重点实验室南京航空航天大学材料科学与技术学院,南京211106

出　　处：《化学学报》2016年第2期185-190,共6页Acta Chimica Sinica

基　　金：国家重点基础研究发展计划(973项目)(No.2014CB239701);国家自然科学基金(Nos.21173120;51372116);江苏省自然科学基金(BK2011030);中央高校基本科研业务费专项资金(NP2014403;NJ20140004);江苏高校优势学科建设工程项目资助~~

摘　　要：以二氧化锗和二水合醋酸锌为原料,采用水热法制备了锗酸锌纳米棒,并将其与氧化石墨烯复合,制备了石墨烯包覆的锗酸锌纳米棒三维复合材料.SEM等测试表明,锗酸锌纳米棒均匀地穿插在石墨烯片中,阻止了石墨烯片之间相互堆垛,而石墨烯片层之间相互连接,形成三维的空间导电网络,提高了材料的电子导电性.电化学测试表明,石墨烯片作为稳定的框架,能够有效缓冲活性物质在脱嵌锂过程中产生的体积变化,在500 m A·g^(-1)电流密度下循环190次后,Zn_2GeO_4@RGO复合材料的嵌锂容量仍有1189.5 m Ah·g^(-1);在3.2 A·g^(-1)的大电流密度下,嵌锂容量达到449.5m Ah·g^(-1),表明该复合材料具有优异的长循环稳定性和良好的倍率性能.Commercial graphite anode material for lithium-ion batteries（LIB） with a theoretical specific capacity of 372 m Ah·g^-1 is unable to satisfy the requirements of increasing mobility and high energy demands. Therefore, it is necessary to develop alternative anode material with high specific capacity. In recent years, a large amount of research has been worked out in the area of high capacity anode materials, for example, silicon（Si） and germanium（Ge）. However, the large volume changes of Si and Ge during the charge and discharge process result in the cracking and pulverization of active material and delamination from the current collector, leading to a rapid decay during the cycling. As a semiconductor, Zn2GeO4 possesses a high capacity of 1443 m Ah·g^-1 which is 90.19% as high as Ge. Nevertheless, the weight rate of germanium element in Zn2GeO4 is only 27.15%, which can effectively cut down the cost of anode material. In this work, Zn2GeO4 nanorods were synthesized through a hydrothermal method by using GeO2 and Zn（CH3COO）2·2H2O and combined with RGO to form a 3D composite. In a typical synthesis, 1.10 g Zn（CH3COO）2·2H2O and 0.52 g GeO2 was added into 15 m L deionized（DI） water and the p H of the mixture was adjusted to 7-8 by using NaOH aqueous solution. Then, the hydrothermal treatment was performed at 140 ℃ for 24 h in an oven to obtain Zn2GeO4 nanorods. Finally, the Zn2GeO4 nanorods were filtrated with GO to form a uniform membrane and reduced by hydrazine hydrate. The Zn2GeO4 nanorods and Zn2GeO4@RGO composite were characterized by X-ray diffraction（XRD）, scanning electron microscopy（SEM）, high-resolution transmission electron microscopy（HRTEM）, Raman spectroscopy, etc. SEM and TEM testified that Zn2GeO4 nanorods were firmly adhered on the surface of graphene sheets, which can effectively avoid the stacking of graphene sheets. The graphene sheets connected with each other to form an electric conductive network, which can improve the electrical conductivity of the comp

关 键 词：锂离子电池 负极材料 锗酸锌纳米棒 还原氧化石墨烯 水热法 

分 类 号：TM912[电气工程—电力电子与电力传动] TB332[一般工业技术—材料科学与工程]