Issue 1, 2020

Controllable and stable organometallic redox mediators for lithium oxygen batteries

Abstract

The use of electrocatalysis in lithium–oxygen batteries is mandatory for reducing the over-potentials of the oxygen evolution reaction (OER), below the levels that endanger the anodic stability of the electrolyte solutions and the carbon electrodes. The most effective catalysts for the OER are solubilized redox mediators that may be oxidized at relatively low potentials, but still capable of oxidizing Li2O2 back to molecular oxygen. Since for the effective and long-term utilization of redox mediators in lithium–oxygen cells a clear evaluation of their stability is essential, we have developed a useful methodology for that purpose. This revealed, quite surprisingly, that most commonly used redox mediators are unstable in lithium–oxygen cells, even under argon atmosphere and without being in contact with Li anodes. Using the abovementioned methodology for evaluating efficiency, we now introduce corrole-chelated metal complexes as stable redox mediators in lithium oxygen batteries. This was achieved by taking advantage of the facile methods for introducing changes in the corrole ligands and by choosing properly the central transition metal cation, two aspects that allow for adjusting the redox properties of the metal complexes for the operative voltage window. We outline further directions and believe that this work will promote optimized selection of redox mediators for lithium–oxygen batteries.

Graphical abstract: Controllable and stable organometallic redox mediators for lithium oxygen batteries

Article information

Article type
Communication
Submitted
06 jul 2019
Accepted
29 aug 2019
First published
29 aug 2019

Mater. Horiz., 2020,7, 214-222

Controllable and stable organometallic redox mediators for lithium oxygen batteries

W. Kwak, A. Mahammed, H. Kim, T. T. Nguyen, Z. Gross, D. Aurbach and Y. Sun, Mater. Horiz., 2020, 7, 214 DOI: 10.1039/C9MH01043B

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