Controllable and stable organometallic redox mediators for lithium oxygen batteries

Won Jin Kwak, Atif Mahammed, Hun Kim, Trung Thien Nguyen, Zeev Gross, Doron Aurbach, Yang Kook Sun

Research output: Contribution to journalArticlepeer-review

16 Scopus citations

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.

Original languageEnglish
Pages (from-to)214-222
Number of pages9
JournalMaterials Horizons
Volume7
Issue number1
DOIs
StatePublished - Jan 2020

Bibliographical note

Publisher Copyright:
© 2019 The Royal Society of Chemistry.

Funding

This work was supported by a Human Resources Development programme (No. 20184010201720) of a Korea Institute of Energy Technology Evaluation and Planning (KETEP) grant, funded by the Ministry of Trade, Industry and Energy of the Korean government and this work was also supported by the Global Frontier R&D Programme (NRF-2013M3A6B1078875) on the Center for Hybrid Interface Materials (HIM), by the Ministry of Science, ICT & Future Planning. DA and ZG acknowledge support from the Israel Committee of High Education in the framework of the INREP consortium.

FundersFunder number
Center for Hybrid Interface Materials
Global Frontier R&D ProgrammeNRF-2013M3A6B1078875
HIM
Ministry of Trade, Industry and Energy
Ministry of Science, ICT and Future PlanningDA
Korea Institute of Energy Technology Evaluation and Planning
Planning and Budgeting Committee of the Council for Higher Education of Israel

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