Abstract Using graphene oxide (GO) and titanium dioxide (TiO2), various types of composites comprised of graphene-bonded and grafted anatase TiO2 were synthesized without employing a cross-linking reagent in this study. Graphene sheets were uniformly dispersed among the TiO2 particles, to enhance the cyclability and electronic conductivity of the TiO2 anode for lithium ion batteries. A composite of GO prepared with three types of TiO2 (nanoparticles, nanorods, nanofibers) were synthesized by hydrothermal followed by calcination treatment. The reduction of GO increased simultaneously after calcination under argon atmosphere at 400 °C for 4 h. To achieve overall better electrochemical performance we used the anatase type of TiO2. The physicochemical properties were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-Ray powder diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy. Surface properties were measured by the Brunauer–Emmett–Teller (BET) & Barrett–Joyner–Halenda (BJH) method. The electrochemical properties were also investigated by Galvanostatic charge-discharge and Electrochemical Impedance Spectra (EIS). TiO2 nanoparticles composite with graphene delivered rate capability of 155 mAh g−1 at 0.5 C and restored the rate capacity of 109 mAh g−1 after 20 C, with a capacity loss of 30%. TiO2 nanorods composite with graphene benefited from its unique morphology exhibited rate capability of 124 mAh g−1 at 0.5 C and regain the rate capability of 97 mAh g−1, with a capacity loss of 22%. In addition, TiO2 nanofibers graphene composite with low surface area 19 m2 g−1 and pore volume of 0.086 cm3 g−1 transported rate capability of 68 mAh g−1 at 0.5 C and recover the rate capacity of 64 mAh g−1 after 20 C owing to its higher value of lithium-ion diffusion coefficient.

中文翻译：

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TiO 2 /石墨烯纳米复合材料作为锂二次电池负极材料的电化学性能和表征的比较研究

摘要 在这项研究中，使用氧化石墨烯 (GO) 和二氧化钛 (TiO2)，在不使用交联剂的情况下合成了由石墨烯键合和接枝锐钛矿型 TiO2 组成的各种类型的复合材料。石墨烯片均匀地分散在 TiO2 颗粒中，以提高锂离子电池 TiO2 负极的循环性能和电子导电性。通过水热和煅烧处理合成了由三种类型的 TiO2（纳米颗粒、纳米棒、纳米纤维）制备的 GO 复合材料。在氩气气氛下在 400°C 下煅烧 4 小时后，GO 的还原同时增加。为了实现整体更好的电化学性能，我们使用了锐钛矿型 TiO2。通过扫描电子显微镜（SEM）表征理化性质，透射电子显微镜 (TEM)、X 射线粉末衍射 (XRD)、X 射线光电子能谱 (XPS) 和拉曼光谱。表面特性通过 Brunauer-Emmett-Teller (BET) 和 Barrett-Joyner-Halenda (BJH) 方法测量。还通过恒电流充放电和电化学阻抗谱（EIS）研究了电化学性质。TiO2 纳米颗粒与石墨烯复合在 0.5 C 时提供 155 mAh g-1 的倍率容量，并在 20 C 后恢复 109 mAh g-1 的倍率容量，容量损失为 30%。TiO2 纳米棒复合石墨烯得益于其独特的形态，在 0.5 C 时表现出 124 mAh g-1 的倍率能力，并重新获得 97 mAh g-1 的倍率能力，容量损失为 22%。此外，