石墨烯/钴镍双氢氧化物复合材料的制备及其超电容特性

采用氧化石墨(GO)还原法制备石墨烯(GNS),以氨水为沉淀剂,在石墨烯存在的情况下,通过Co²⁺和Ni²⁺化学共沉积的方法合成了石墨烯/钴镍双氢氧化物复合电极材料,采用红外光谱(FT-IR)、X射线衍射(XRD)、场发射扫描电子显微镜(FE-SEM)、比表面积测试(BET)等技术手段表征了产物的组成、结构和形貌,用循环伏安、恒电流充放电等测试方法对复合材料的电化学性能进行了研究。 研究发现,石墨烯纳米片均匀分散在钴镍双氢氧化物中,改善了钴镍双氢氧化物的传导性和结构稳定性。 电化学测试表明,在1 A/g的电流密度下,复合材料比电容高达2770 F/g,且循环500次后,比电容仍能保持93.4%,呈示该复合材料具有优异的电化学性能。

Synthesis and Supercapacitor Properties of Graphene/Co-Ni Layered Double Hydroxides Composites

The graphene(GNS)/Co-Ni layered double hydroxides(LDH) composites were synthesized through a chemical co-precipitation process of Co²⁺ and Ni²⁺ using NH₃·H₂O as a precipitator in the presence of graphene. The compositions, microstructures and morphologies of these samples were systematically characterized by Fourier transform infrared(FT-IR) spectroscopy, X-ray diffraction(XRD), field emission scanning electron microscopy(FE-SEM) and nitrogen adsorption(BET). The electrochemical performance of these composites was investigated by cyclic voltammetry and constant current charge/discharge techniques. It is found that Co-Ni LDH nanoparticles are well dispersed on the surface of GNS as the spacer to prevent the GNS from aggregation and improve the conductivity and structure stability of the Co-Ni LDH. The results show that the GNS/Co-Ni LDH electrode exhibits excellent electrochemical performance. Its specific capacitance as a single electrode is up to 2770 F/g and remains about 93.4% of the initial value after 500 potential cycles at the current density of 1 A/g.