锂离子电池纳米结构正极材料LiV3O8的制备及性能

采用水热合成方法，在不同水热合成温度下制备了具有纳米结构的锂离子电池正极材料LiV3O8。并利用X射线衍射、透射电镜、恒流充放电、循环伏安以及电化学交流阻抗等测试手段对其结构、形貌和性能做了研究。结果表明，不同的水热合成温度影响到产物的结构、形貌和性能。随着水热温度的升高，粒子的直径随之增大，而形貌和尺寸的均一性则有所降低。电化学测试结果表明水热180℃得到产物的比容量较高，具有良好的电化学可逆性，而且随着水热温度的升高，材料的电荷转移电阻依次减小，有利于锂离子的嵌入与脱出，比容量也随之增加。可见材料的结构中存在一定的非晶缺陷，以及粒子具有一定范围内的尺寸分布，对材料的电化学性能有改善作用。

Preparation and Properties of LiV3O8 Nanomaterialsas the Cathode Material for Li-ion Batteries

LiV3O8 cathode nanomaterials were synthesized by a hydrothermal route at different hydrothermal reaction temperature. The structure, morphology and proprieties of the samples were investigated by several tests such as XRD, TEM, cyclic voltammetry (CV), galvanostatic charge–discharge and electrochemical impedance spectroscopy (EIS) techniques. The results of XRD and TEM show that different hydrothermal temperature result in different structure and morphology of the samples, which lead to different electrochemical properties. With the increase of hydrothermal reaction temperature, the diameter of the particles accreted and size distribution forms inhomogeneous. The specific discharge capacity of the sample which synthesized at hydrothermal temperature 180℃ is highest, and has a good reversibility. In the pace of the increasing of hydrothermal temperature, the charge transfer resistance of the LiV3O8 is decrease, it is good for outset and inset of lithium-ion during the charging-discharging process. That is to say, there some defect-amorphous in the structure of materials, and there certain dimension distributing of the particles, which can improve electrochemical performances of the LiV3O8 cathode nanomaterials .