Issue 17, 2020

Neutral pH aqueous redox flow batteries using an anthraquinone-ferrocyanide redox couple

Abstract

Anthraquinone-2,7-disulfonic acid (2,7-AQDS) and ferrocyanide including potassium and sodium salts are used as a redox couple for neutral aqueous redox flow batteries (ARFBs). In 1 M potassium chloride (KCl) electrolyte of neutral pH, the electron transfer rate and redox reactivity of 2,7-AQDS are better than those in acidic electrolyte. Furthermore, ferrocyanide is attacked by the hydroxyl group within the alkaline electrolyte, however this does not happen in KCl because there are no hydroxyl groups in KCl. The low solubility of 2,7-AQDS is enhanced in 1 M KCl using an ethyleneglycol (EG) additive and the solubility of the ferrocyanide also increases when using the mixed cations of potassium and sodium. This benefit arises because of the fact that the EG additive forms hydrogen bonds with water within the electrolyte and 2,7-AQDS, while ferrocyanide mixed with different cations increases the solubility due to ion pair formation. Based on that, the ARFB using 2,7-AQDS and ferrocyanide shows high coulombic efficiency (98% at 40 mA cm−2) and capacity (17.8 A h L−1) with a low capacity decay rate (>99% until 100 cycle).

Graphical abstract: Neutral pH aqueous redox flow batteries using an anthraquinone-ferrocyanide redox couple

Article information

Article type
Paper
Submitted
07 Feb 2020
Accepted
13 Mar 2020
First published
15 Mar 2020

J. Mater. Chem. C, 2020,8, 5727-5731

Neutral pH aqueous redox flow batteries using an anthraquinone-ferrocyanide redox couple

W. Lee, A. Permatasari and Y. Kwon, J. Mater. Chem. C, 2020, 8, 5727 DOI: 10.1039/D0TC00640H

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements