Specific carbon/iodide interactions in electrochemical capacitors monitored by EQCM technique

Anetta Platek-Mielczarek,Krzysztof Fic,Elzbieta Frackowiak

doi:10.1039/d0ee03867a

Abstract

This paper reports on the ion fluxes at the interfaces of various porous carbon electrodes/aqueous solutions of alkali metal cations (Na+, K+ and Rb+) and iodide anions, monitored by an electrochemical quartz crystal microbalance (EQCM).

Highlights

An increase in the energy output of electrochemical capacitors is still of very high interest;[1,2] the introduction of redoxactive electrolytes has been proposed.[3,4,5,6,7,8,9] Application of an electrolytic solution demonstrating redox activity combinesEven if the capacitance of redox based systems is improved by incorporating faradaic processes, electrochemical capacitors with aqueous electrolytes cannot replace their organic-based counterparts, regardless of their competitive energy density, but they are highly concurrent due to their power, cost andPaper ‘green’ character
The capacitive character of the curve is attributed to the electrical double-layer (EDL) charge/discharge process
For systems based on faradaic storage, the current and potential are in the same phase

Summary

Introduction

An increase in the energy output of electrochemical capacitors is still of very high interest;[1,2] the introduction of redoxactive electrolytes has been proposed.[3,4,5,6,7,8,9] Application of an electrolytic solution demonstrating redox activity combinesEven if the capacitance of redox based systems is improved by incorporating faradaic processes, electrochemical capacitors with aqueous electrolytes cannot replace their organic-based counterparts, regardless of their competitive energy density, but they are highly concurrent due to their power, cost andPaper ‘green’ character. The correlation of the electrode and electrolyte properties with the electrochemical performance has been reported in numerous reports, presenting various approaches to the capacitance of the electrical double-layer.[35,36,37,38,39,40,41,42,43]

Objectives

Results

Conclusion