Metal Oxide Nanoparticles at Functionalized Graphene Surface for electrochemical Supercapacitors

Description:
The potential for exhaustion of non-renewable fossil fuels and the environmental impacts associated with greenhouse gas emissions are the main motivations for increasing global demands for developing alternative renewable and sustainable energy supplies. Among the different types of energy storage devices, supercapacitors, have attracted notable attention due to their environmental friendliness, capacity to safely provide high power, rapid charging with extremely long cycle life, lightweight, and flexible portable energy storage devices properties. A typical supercapacitor is configured by two electrodes, a separator, an electrolyte, and the current collector. During all of these components, the electrodes are essential parts of a supercapacitor, and the material of the electrodes is the top priority. Carbon-based materials are commonly used as EDLCs electrodes, due to their large surface area, high conductivity, thermal and chemical stability, low cost, and established fabrication techniques. But the applications of this type of material are limited by low electroactive surface area, due to the chemical inert and hydrophobic feature of pure graphene. Therefore, we introduce the synthesis of reduced graphene oxide-metal oxide nanocomposite via a one-step, green and efficient method. The current method is based on the reduction of metal precursors and graphene oxide (GO) in a single step using glucose as a reducing agent. The rGO/metal oxide nanocomposite contains rGO as a substrate for homogeneous growth of metal oxide nanoparticles to improve the electrical conductivity and the mass ratio of the metal oxide participating in the electrochemical reaction, while the metal oxide nanoparticles can serve as a separator to inhibit the aggregation of the rGO and maximize the specific capacitance. The proposed synthetic method is accomplished without any annealing or calcination process. This is an advantage in reducing energy consumption during the preparation step.

Speaker: Wen Sun - University of North Dakota