Improvement in the capacitance of a carbon electrode prepared using water-soluble polymer binder for a capacitive deionization application

It is very important to increase the wetted surface area of a carbon electrode for high capacitive deionization performance. To increase the wettability of a carbon electrode, we fabricated carbon electrodes by using water-soluble polymer binder, polyvinyl alcohol (PVA). The electrochemical properties of the PVA-bonded carbon electrode were compared with another that was prepared using hydrophobic binder, polyvinylidene fluoride (PVdF). Electrochemical methods - cyclic voltammetry, chronoamperometry, and electrical impedance spectroscopy - were used to characterize the electrochemical properties of the electrodes. As might be expected, it was confirmed that the PVA-bonded electrode was more wettable than the PVdF-bonded one, based on contact angle measurements. From the cyclic voltammetric analysis, we found that the specific capacitance was 74.4-80.3 Fg-1 for the PVdF-bonded electrode and 89.6-99.8 Fg-1 for the PVA-bonded electrode, depending on the potential, indicating a 13.3-30.1