Understanding the Operating Mechanism of Aqueous Pentyl Viologen/Bromide Redox-Enhanced Electrochemical Capacitors with Ordered Mesoporous Carbon Electrodes
Artikel i vetenskaplig tidskrift, 2021

Compared to traditional electric double-layer capacitors, redox-enhanced electrochemical capacitors (redox-ECs) show increased energy density and steadier power output thanks to the use of redox-active electrolytes. The aim of this study is to understand the electrochemical mechanisms of the aqueous pentyl viologen/bromide dual redox system at the interface of an ordered mesoporous carbon (CMK-8) and improve the device performance. Cells with CMK-8 carbon electrodes were investigated in several configurations using different charging rates and potential windows. The pentyl viologen electrochemistry shows a mixed behavior between solution-based diffusion and adsorption phenomena, with the reversible formation of an adsorbed layer. The extension of the voltage window allows for full reduction of the viologen molecules during charge and a consequent increase in the specific discharge energy delivered by the cell. Investigation of the mechanism indicates that a 1.5 V charging voltage with a 0.5 A g-1 charging rate and fast discharge rate produces the best overall performance.

mesoporous carbon

viologen anolyte

redox electrolytes

supercapacitors

aqueous hybrid electrochemical capacitors

Författare

Giulio Calcagno

Chalmers, Kemi och kemiteknik, Tillämpad kemi, Teknisk ytkemi

Brian Evanko

University of California

G.D. Stucky

University of California

Elisabet Ahlberg

Göteborgs universitet

Seung Joon Yoo

Gwangju Institute of Science and Technology

Anders Palmqvist

Chalmers, Kemi och kemiteknik, Tillämpad kemi, Teknisk ytkemi

ACS Applied Materials & Interfaces

1944-8244 (ISSN) 1944-8252 (eISSN)

Vol. In Press

Energi OCH Effekt: Hybridsuperkondensatorer

Energimyndigheten (39045-1), 2015-01-01 -- 2018-12-31.

Ämneskategorier

Materialkemi

Annan kemiteknik

Annan kemi

DOI

10.1021/acsami.1c13378

Mer information

Senast uppdaterat

2021-11-02