Widening Electrochemical Window of Mg Salt by Weakly Coordinating Perfluoroalkoxyaluminate Anion for Mg Battery Electrolyte
Energy storage concepts based on multivalent ion chemistries, such as Mg2+, promise very high volumetric energy density, however require improvements in electrolyte (Mg salt and solvent) electrochemical window to reach their full potential. Hypothetically the window of Mg salt could be widened by di...
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Published in | Journal of the Electrochemical Society Vol. 166; no. 8; pp. A1510 - A1519 |
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Main Authors | , , , , , , , , |
Format | Journal Article |
Language | English |
Published |
United States
The Electrochemical Society
2019
IOP Publishing |
Subjects | |
Online Access | Get full text |
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Summary: | Energy storage concepts based on multivalent ion chemistries, such as Mg2+, promise very high volumetric energy density, however require improvements in electrolyte (Mg salt and solvent) electrochemical window to reach their full potential. Hypothetically the window of Mg salt could be widened by disfavoring the cathodic decomposition pathway of a thermodynamically and anodically stable anion, rendering it kinetically inert toward Mg+-mediated reduction. Computational and electrochemical analyses on Mg[TPFA]2 ([TPFA]− = [Al{OC(CF3)3}4]−) support this hypothesis, and showcase a widened electrochemical window as a result of mitigated cathodic decomposition as well as enhanced anodic stability from electron-withdrawing CF3 groups. Detailed NMR and IR spectroscopy and scanning electron microscopy/energy-dispersive X-ray spectroscopy further support that the weak coordination to Mg2+ in solution is important for maintaining the wide electrochemical window of Mg salt. |
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Bibliography: | 0751908JES AC02-06CH11357 USDOE Office of Science (SC), Basic Energy Sciences (BES) |
ISSN: | 0013-4651 1945-7111 |
DOI: | 10.1149/2.0751908jes |