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

Abstract

Ionic 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.

Proton‐Conducting Polymers: Key to Next‐Generation Fuel Cells, Electrolyzers, Batteries, Actuators, and Sensors

“…A novel approach to enhancing the proton conductivity of supercapacitor electrodes was explored by Jia and coworkers. [47] The research specifically examined the use of Nafion as a binder mixed with carbonized maple wood as a biochar active material with high electrical conduction. This combination improved the specific capacitance in H 2 SO 4 electrolytes considerably compared to electrodes using polyvinylidene difluoride (PVDF) binders because the existence of H 3 O + transport channel in Nafion could lead protons to reach the bilayer reaction interface quickly (Figure 7a).…”

“…A novel approach to enhancing the proton conductivity of supercapacitor electrodes was explored by Jia and co‐workers [47] . The research specifically examined the use of Nafion as a binder mixed with carbonized maple wood as a biochar active material with high electrical conduction.…”

“… (a) Specific capacitances under different current densities tested in 1 mol L −1 H 2 SO 4 . The electrodes were in an area of 2×2 cm 2 with mass loadings of approximately 1.0 mg or 2.0 mg, which were designated as PVDF−C‐1, PVDF−C‐2, Nafion‐C‐1, and Nafion‐C‐2 (Reproduced with permission [47] . Copyright 2022 John Wiley and Sons).…”

Versatile Composite Binder with Fast Lithium-Ion Transport for LiCoO2 Cathodes

“…A binder is a significant contributor to the evolution of the electrode structure. The development of new binders with different functions has gradually become a key to solve the low ion transport performance. − Building the efficient ion transport channels inside the electrodes and realizing the high-speed transport is one of the key research directions for future battery technologies. − More specifically, the binder determines the microscopic and interfacial evolution during electrode fabrication through its own physical and chemical properties. − Poly­(vinylidene fluoride) (PVDF) is a commonly used binder in LIBs owing to its electrochemical stability. However, the low ionic conductivity of PVDF results in a slow Li + diffusion rate, − which, in turn, affects the reaction kinetics and further restricts the application of high-rate LIBs. − Therefore, new binders with good adhesion properties and high-rate properties are significant for the manufacture of high-power LIBs.…”