Electrochemical Reduction of Oxygen in Aprotic Ionic Liquids Containing Metal Cations: A Case Study on the Na–O2 system

• DOI: 10.1002/cssc.201601464
• Publication Date: 2017-01-19T14:34:45Z
• Authors: Eneko Azaceta; Lukas Lutz; Alexis Grimaud; Jose Manuel Vicen...; Said Hamad; Luis Yate; German Cabañero; Hans‐Jurgen Grande; Juan A. Anta; Jean‐Marie Tarascon; Ramon Tena‐Zaera
• Keywords: Oxygen evolution

Abstract Metal–air batteries are intensively studied because of their high theoretical energy‐storage capability. However, the fundamental science electrodes, electrolytes, and reaction products still needs to be better understood. In this work, ionic liquid N ‐butyl‐ ‐methylpyrrolidinium bis(trifluoromethanesulfonyl)imide (PYR14TFSI) was chosen study influence a wide range metal cations (M n + ) on electrochemical behavior oxygen. The relevance theory Lewis hard soft acids bases predict satisfactorily reduction potential oxygen in electrolytes containing is demonstrated. Systems with intermediate M acidity shown facilitate oxide formation, whereas hampered by acid such as sodium lithium. Furthermore, DFT calculations energy formation resulting oxides rationalize effect reduction. A case Na–O 2 system described detail. Among other things, Na concentration electrolyte control pathway (solution precipitation vs. surface deposition) which discharge product grows. All all, insights for design advanced metal–air batteries, Na–air particular, provided.