The electrochemical characterisation of graphite felts

Abstract

With the increasing demand for advanced energy storage, redox flow batteries (RFBs) are a rapidly growing market and research area. Carbon fibre based materials like graphite felts (GFs) are commonly used in RFBs as electrodes due to their electrochemical activity, high permeability for liquids, high surface area and relatively low cost. Previous characterisation of GFs has involved flow systems, which can be complicated to replicate and expensive. Using pre-treatment techniques to ensure sufficient wetting, GFs can be used effectively in quiescent electrochemistry. By combining the experimental voltammograms with digital simulations, key properties such as capacitance, electrode kinetics, average pore size and electrochemical surface area can be determined. This allows for the rapid and low cost examination of multiple GFs and pre-treatment methods, providing a useful tool for RFB development. In addition, the GF electrodes used in the study show promising limit of detection values, with initial experiments suggesting these electrodes may have applications in electroanalysis.