TiO2/石墨烯复合物的制备及其嵌脱锂行为研究

以钛酸丁酯为TiO₂前驱体, 通过水热法制得TiO₂/石墨烯复合物。使用X射线衍射(XRD)、热重分析(TG)、透射电镜(TEM)、扫描电镜(SEM)和电化学充放电等手段对材料进行了表征和分析。结果表明: TiO₂颗粒均匀地分散在石墨烯的表面, 复合物中石墨烯的含量为24.67%。当该材料用作锂离子电池负极材料时, 在2C的放电倍率下, 首次放电容量为384.35 mAh/g, 循环100次后的放电容量为130.26 mAh/g, 是纯TiO₂电极放电容量的2.93倍。与纯TiO₂电极相比, TiO₂/石墨烯复合物的电荷转移电阻较低。TiO₂/石墨烯复合物具有较好的倍率性能和较高的电化学反应活性。

Preparation and Electrochemical Lithium Insertion of TiO2/Graphene Nanocomposites

TiO₂/Graphene nanocomposites was synthesized through solvothermal method with butyl titanate as TiO₂ precursor. The character of nanocomposites was measured by scanning electron microscope (SEM), thermogravimetry (TG), X-ray diffraction (XRD) and electrochemical measurements. The result shows that TiO₂ nanoparticles are uniformly wrapped in the graphene sheets. The graphene content of TiO₂/Graphene nanocomposite is 24.67wt%. When the TiO₂/Graphene nanocomposites are used as anode materials for lithium-ion battery, the initial discharge capacity of the nanocomposite electrode is 384.35 mAh/g at a current rate of 2C. It delivers a capacity of 130.26 mAh/g after 100 charge-discharge cycles, 2.93 times as high as that of the pure TiO₂ nanoparticles electrode_. The charge transfer resistance of the nanocomposites is lower than that of TiO₂. The nanocomposite electrode exhibits good rate capability and excellent electrochemical performance as compared with the pure TiO₂ electrode.