Abstract
High donor number (DN) solvents in Li—O2 batteries that dissolve superoxide intermediates in lithium peroxide (Li2O2) formation facilitate high capacities at high rates and avoid early cell death. However, their beneficial characteristics also result in an instability towards highly reactive superoxide intermediates. Furthermore, Li—O2 batteries would deliver a superior energy density, but the multiphase electrochemical reactions are difficult to achieve when operating with only solid catalysts. Herein we demonstrate that vanadium(III) acetylacetonate (V(acac)3) is an efficient soluble catalyst that can address these problems. During discharge, V(acac)3 integrates with the superoxide intermediate, accelerating O2 reduction kinetics and reducing side reactions. During charge, V(acac)3 acts as a redox mediator that permits efficient oxidation of Li2O2. The cells with V(acac)3 exhibit low overpotential, high rate performance, and considerable cycle stability.
Original language | English |
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Pages (from-to) | 12553-12557 |
Number of pages | 5 |
Journal | Angewandte Chemie - International Edition |
Volume | 58 |
Issue number | 36 |
Early online date | 28 Aug 2019 |
DOIs | |
Publication status | Published - 2 Sept 2019 |
Bibliographical note
Funding Information:This work was financially supported by Liaoning Revitalization Talents Program—Pan Deng Scholars (XLYC1802005), Liaoning BaiQianWan Talents Program, National Science Fund of Liaoning Province for Excellent Young Scholars, Science and Technology Innovative Talents Support Program of Shenyang (RC180166), Australian Research Council (ARC) through Discovery Early Career Researcher Award (DE150101306) and Linkage Project (LP160100927), Faculty of Science Strategic Investment Funding 2019 of University of Newcastle, and CSIRO Energy. The computational work was supported by the Robert A. Welch Foundation Grant F-1841 and the Texas Advanced Computing Center.
Publisher Copyright:
© 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Keywords
- donor number
- Li–O battery
- reaction mechanism
- soluble catalyst
- vanadium(III) acetylacetonate