【作者】 王宁；

【导师】 孙晓明；

【作者基本信息】 北京化工大学 ， 化学工程与技术， 2012， 硕士

【摘要】 本论文主要研究了氧化石墨烯的制备和还原，石墨烯/Fe3O4、石墨烯/TiO2两种复合材料的制备及其在锂离子电池负极材料的应用，还研究了石墨烯/LDH的制备及其作为超级电容器电极材料的应用。本文通过改进的Hummers法，使用浓硫酸插层及高锰酸钾氧化，将天然石墨氧化，后经过超声制得了氧化石墨烯。该氧化石墨烯的水溶液和异丙醇做溶剂通过水热法制取了负载物分散性好的石墨烯/FeOOH复合物，将该复合物在惰性气氛下管式炉600℃处理可得到石墨烯/Fe₃O₄复合材料，通过XRD、SEM、TEM等手段进行表征，证明Fe₃O₄纳米颗粒成功的负载在石墨烯表面。该复合物作为锂离子电池的负极材料在1-3V下，首次充放电容量为1250mAh g^-1，30次循环后容量930mAh g^-1，相对以往报道的Fe₃O₄纳米颗粒单独作为锂离子电池负极材料在容量和循环性能都有明显的改进和提升。通过醇和酸酯化反应及钛酸四丁酯水解反应的协同作用，使用钛酸四丁酯作为钛源，乙醇和乙酸为反应溶剂，水热釜中120℃反应10h制的了锐钛矿晶型的TiO₂纳米棒和石墨烯的复合产物，该产物作为锂离子电池负极材料，1-3V电压范围内，首次容量约196mAh g^-1，55次循环后100mAh g^-1，也表现出较大的容量和较好的循环性能。本论文还用氧化石墨烯的水和DMF混合溶液，在加入无机盐和尿素的条件下，180℃下水热48h制得了Ni-Al LDHs/石墨烯复合物。通过XRD、TEM、HRTEM对产物进行了表征，并将该复合物使用微量PVDF粘结在泡沫镍片上，在1M的KOH溶液中进行了电化学的测试。测试表明，该复合物有非常好的电化学性能，在5mv/s的速率下循环伏安测试表现出两对明显的氧化还原峰，分别对应了两个不同环境中镍原子的氧化还原的过程。经过放电曲线的计算，该复合物作为超级电容器电极材料的比容量为486F·g^-1。此外，还研究了不同镍铝比例对该复合物电化学性能的影响。通过循环伏安曲线和充放电曲线表明，在镍铝比为3时的复合物具有最大的容量和最高的放电平台电压。更多还原

【Abstract】 The thesis mainly contains three parts of works: the synthesis andreduction of graphene oxide, the synthesis of graphene/Fe₃O₄、graphene/TiO₂and their properties as an anode materials for lithium ionbatteries, the synthesis of graphene/Ni-Al LDH and its properties asadvanced electrochemical pseudocapacitor material.GO is made by an improved Hummers method followed bysupersonic progress. Graphene/FeOOH hybrid composite is prepared bysolvothermal method, in which the aqueous solution of GO andisopropanol act as a solvent and FeCl3as the crystal seeds. Then heat thegraphene/FeOOH hybrid composite at600℃in the inert atmosphere for4-5h and get the product of graphene/Fe₃O₄. The product structure isconfirmed by SEM, TEM and XRD characterizations. Cycled between1and3V at35mA g^-1demonstrates a first discharge capacity of1250mAh g^-1, after30cycles the capacity is also930mAh g^-1, the hybridmaterial realize a high capacity and good cycling performance.Graphene/TiO₂hybrid composite is prepared by solvothermal method, in which the glycol solution of GO and acetic acid act as asolvent and tetrabutyl titanate as the crystal seeds. In the Teflon reactorhydrolysis of titanium tetrachloride and esterification occursimultaneously. The product structure is confirmed by SEM, TEM andXRD characterizations. Cycled between1and3V at30mA g^-1demonstrates a first discharge capacity of196mAh g^-1, after50cycles thecapacity is also100mAh g^-1a, the hybrid material realize a high capacityand good cycling performance.Moreover, we get Ni-Al LDHs/graphene hybrid material bysolvothermal method in180℃for48h. The product structure isconfirmed by SEM, TEM, HRTEM and XRD characterizations and thendeposite it in nickel foam sheet by PVDF for testing. In the CV cruves,the hybrid shows two redox peaks correspond to two differentNi（II）/Ni（III）. The hybrid material performances good electrochemicalcharacteristics as pseudocapacity with a capacitance of486F·g^-1。We alsostudy the CV and Discharge cruves of the hybrid material with differentnickel and aluminum rato. The results show that the hybrid material hasthe best performance with the nickel and aluminum rato at3.更多还原