NiCo2O4/氧化石墨烯复合材料制备与电化学性能研究

为了研究NiCo2O4/氧化石墨烯(NiCo2O4/GO)复合材料的电化学性能，本文通过先水热合成前驱体再煅烧的方法制备了一系列NiCo2O4/GO复合材料.利用X射线衍射(XRD)、扫描电子显微镜(SEM)和电化学方法对其进行物理表征，其中以GO质量浓度为1 mg/mL悬浊液制备出的NiCo2O4 /GO-3复合材料呈类海胆状结构.在1 M KOH水溶液中使用循环伏安法、恒电流充/放电法和交流阻抗法研究了NiCo2O4/GO复合材料电化学性能.研究表明，与纯NiCo2O4相比，制备的NiCo2O4 /GO复合材料的比容量和赝电容性能均有明显提高，这主要是由于NiCo2O4 /GO复合材料中NiCo2O4与GO纳米片的相互作用形成的高孔隙率复合结构；NiCo2O4 /GO-3复合材料在电流密度为0.5~3.0 A/g时，比电容超过650 F/g，具有良好的倍率性能和高比容量.采用本文方法合成的NiCo2O4/GO复合材料，既提高了其倍率性能又保证了高比容量，是一种良好的超级电容器电极材料.
The composites of NiCo2O4/graphene oxide nanosheets(NiCo2O4/GO) were prepared through a facile hydrothermal route followed by calcination. The morphology and microstructure of the products were characterized by X-ray diffraction (XRD), and scanning electron microscopy (SEM). It was found that the composite materials showed a sea urchin-like structure. Electrochemical properties were investigated using cyclic voltammetry and galvanostatic charge/discharge in 1 M KOH aqueous solution. In comparison with pure NiCo2O4, the specific capacity and rate performance of the as-made NiCo2O4/GO composites were significantly improved. This is mainly attributed to the high-density porous structures of the NiCo2O4/GO nanocomposites that were formed during the fabrication process. The NiCo2O4/GO composites showed good cyclic performance and coulomb efficiency with a specific capacitance over 650 F/g at a current density of 0.5 to 3.0 A/g, therefore they can be considered as a fine electrode material for surpercapactiors.