Influence of pore structure and cell voltage of activated carbon cloth as a versatile electrode material for capacitive deionization

Abstract

Activated carbon cloth is a promising electrode material for capacitive deionization to accomplish energy efficient desalination of water. The most attractive feature is the combination of high porosity and the ability to shape binder-free electrodes by simple cutting. The macroporous inter-fiber space also assists facile flow of the aqueous medium. Our work presents a thorough benchmarking of activated carbon cloth materials with different pore structures which show different potentials at zero charge. The studied activated carbon cloth textiles possess a large microporosity with an average pore size of 0.7–1.3 nm and stable electrochemical performance in aqueous media with specific capacitance of up to 125 F/g. In aqueous 5 mM NaCl, the electrodes achieve up to 16 mg/g salt adsorption capacity with charge efficiency of 80% at cell voltage of 1.2 V. Further on, we investigated cell voltages between 0.6 V and 1.2 V and applied our predictive salt adsorption tool that is based on the pore structure to the entire voltage window range. Our work also shows that activated carbon cloth can even be operated without a current collector.