Development of Carbon-based Composite Materials for Energy Storage

Abstract

The following work aims the preparation and characterization of electrodes for supercapacitors employing different carbon materials and their integration functional prototypes. Preparation of electrodes was conducted in two steps; I) formulation and mixing of raw materials and II) coating of the aluminum foil that supports the electrode with the mixture of materials. Different compositions and formulations were carried out to prepare the electrodes. Electrodes were composed by a matrix polymer of PVDF (Polyvinylidene Fluoride) and several carbon material additives (activated carbon, graphite, carbon black, carbon nanotubes and graphene) that ensured a high specific capacity and low electrical resistance. Finally, the build-up of “single-cell” prototypes employing the electrodes was carried out to validate their performance. Galvanostatic charging/discharging cycles, cyclic voltammetry and impedance spectroscopy to characterize the electrodes and prototypes were performed. From these experiments important parameters of a supercapacitor were estimated; equivalent serie resistance (ESR) and specific capacitance (F/g). Results of characterization have shown high capacities and good kinetics in the electrodes developed.