Effect of binder on the electrochemical performance of activated carbon electrodes obtained from waste hazelnut shells: Comparison of PTFE and PVDF

Abstract

In this study, the electrochemical performance of the electrode materials based on two commonly used binders –poly(vinylidene difluoride) (PVDF) and poly(tetrafluoroethylene) (PTFE)– was introduced. The electrochemical performance of the activated carbon electrodes was explored by performing cyclic voltammetry, galvanostatic charge-discharge, and electrochemical impedance spectroscopy techniques. The results showed that the activated carbon electrode prepared at 500 °C with PTFE (AC-500-PTFE) exhibited higher capacitance values at low current rates than the one with PVDF (AC-500-PVDF). The results also revealed that the capacitance values of the AC-500-PVDF electrode for the current rates higher than 1.5 A g−1 were higher than the AC-500-PTFE electrode. The implemented transmission line equivalent circuit model for impedance showed that the capacitance inside the pores was higher for the AC-500-PVDF, and the higher capacitance on the electrode surface was obtained for the AC-500-PTFE. As a result, it is recommended to prefer PTFE binder for low current density, yet a PVDF binder for high current density applications.