V_2O_5核壳结构微米球的合成及其电化学性能  

Synthesis and electrochemical property of core-shelled V_2O_5 microspheres

作　　者：刘泠鑫 黄伯云[1,2] 方国赵 周江[2] 潘安强[2] 梁叔全[2] 

机构地区：[1]中南大学粉末冶金国家重点实验室,长沙410083 [2]中南大学材料科学与工程学院,长沙410083

出　　处：《粉末冶金材料科学与工程》2017年第6期800-807,共8页Materials Science and Engineering of Powder Metallurgy

基　　金：国家高技术研究发展规划(863计划)资助项目(2013AA110106);国家自然科学基金资助项目(51374255;51572299)

摘　　要：中空结构的V_2O_5材料由于在锂离子嵌入和循环稳定性方面有明显优势,获得了科研人员的特别关注。然而通过简易方法来制备均匀且具有复杂内部结构的V_2O_5中空微米球仍面临挑战。本文首次利用V_2O_5、H_2C_2O_4·2H_2O、H_2O和正丁醇进行溶剂热反应,得到蛋黄结构前躯体,然后将前躯体于空气中烧结,获得均匀的多层V_2O_5核壳结构微米球。采用X射线衍射(XRD)、扫描电镜(SEM)、透射电镜(TEM)及电化学测试等手段对其进行表征和测试。V_2O_5核壳结构微米球用作锂离子电池正极材料时,在2.5~4 V电压区间、200 mA/g电流密度条件下放电比容量高达122 m Ah/g,循环200圈后容量保持率高达95.9%。该材料优异的电化学性能主要由于结合了低维和三维纳米结构。Hollow-structured V2O5 materials have drawn special interests because of their advantageous for facile Li＋ ion insertion and good cycling stability. However, the controllable fabrication of V2O5 hollow structures with high uniformity and complex internal structure through simple synthesis procedures still remains challenging. In this study, the uniform multi-shelled core-shelled V2O5 microspheres were fabricated by one-step solvothermal treatment using commercial V2O5, H2C2O4·2H2O, H2O and N-butanol as raw materials followed by subsequent annealing for the first time. X-ray diffraction （XRD）, scanning electron microscopy （SEM）, transmission electron microscopy （TEM） and electrochemical measurements were used to characterize the properties of the materials. Used as cathode materials for lithium-ion batteries, the core-shelled V2O5 microspheres exhibit a high specific discharge capacity of 122 mAh/g at 200 mA/g within a voltage range of 2.5？4 V, with a corresponding capacity retention of 95.9% after 200 cycles. The good electrochemical property of the V2O5 microspheres might be related to the unique core-shelled structure which combines the advantages of both low-dimensional and three-dimensional nanostructures.

关 键 词：V2O5 溶剂热法 核壳结构 锂离子电池 电化学性能 

分 类 号：TM912.9[电气工程—电力电子与电力传动]