Binderless Graphene / Three-Dimensional Microfibrous Carbon Paper Composites Electrode for Electrochemical Applications
Recent advances in nanoscale science and technology provides new opportunities in achieving highly efficient electrodes for electrochemical applications such as: energy storage devices, sensors, catalysts. Synergizing with material chemistry, various nanostructures have great potential in stabilizing and activating the electroactive materials with performances well beyond the scope of traditional fabrication technologies. One of the most promising materials is graphene. Graphene, a 2D planar sheet of hexagonally configured sp2 hybridized carbon atoms, has attracted immense interest since its discovery in 2004. This new material shows excellent tensile strength, ballistic electrical conductivity (in the range of 200,000 cm2 v−1 s−1), high thermal stability (around 5000 Wm−1 K−1), very highly theoretical surface area estimated to 2630 m2 g−1 and outstanding Young’s modulus (1100 GPa). These exceptional physical and chemical characteristics make graphene an excellent candidate as a compound in nanocomposites materials for many applications. For electrochemical applications, the use of graphene needs an electrode preparation process. Conventional methods of preparation of these electrodes comprise three steps: (i) the dispersion of graphene in solution (ii) the formation of composite film with an appropriate binder, and (iii) the assembly of the composite film on a current collector. This conventional process is complicated, inefficient, and expensive. In this work, we report on the development of highly attractive nanostructured samples derived from three-dimensional microfibrous carbon paper uniformly covered with graphene without biender. The synthesized materials were characterized by using scanning electronic microscopy, X-ray diffraction, Raman spectroscopy, cyclic voltammetry, galvanostatic charge–discharge (GCD) and electrochemical impedance spectroscopy techniques. Results of structural characterization confirm the effectiveness of the graphene deposition on the three-dimensional microfibrous carbon paper method. Results of electrochemical tests showed high-resolution responses in different chemical media, which indicate good electrical contact between the graphene and the three-dimensional microfibrous carbon paper substrate. These architectures hold great promise for incorporation into energy storage devices, sensors, catalysts. As first application, the developed process was used to fabricate an efficient electrode for electrochemical capacitor.