Ionic Conductivity Enhancement Achieved by Binder in Electrodes and Its Influence in Supercapacitor

Abstract

AbstractIonic conductivity is a critical factor affecting the electrochemical performance of double layer capacitor. Therefore, additional ion transport channels are introduced by using Nafion as binder in electrode. In this study, carbonized maple as active substance was mixed with binder of Nafion or PVDF to form electrodes. The electrode structures were obtained by scanning electron microscopy and N2 adsorption‐desorption isotherms with the aim of clarifying negligible differences in the microstructure and binding strength of electrodes with different binders. Furthermore, the two electrodes with different binders tested in KOH exhibited similar electrochemical properties. However, in H2SO4 electrolyte, the electrode containing Nafion showed a much higher specific capacitance than that of electrode using PVDF binder. To directly prove the high ionic conductivity of Nafion electrode, concentration battery was constructed using the two electrodes as separators to investigate their liquid junction potential. This study focused on the ionic conduction in electrodes, which could provide suggestions for electrode design, especially for the utilization of commercial supercapacitors.