Coordinated mapping of Li flux and electron transfer reactivity during solid-electrolyte interphase formation at a graphene electrode
Interphases formed at battery electrodes are key to enabling energy dense charge storage by acting as protection layers and gatekeeping ion flux into and out of the electrodes. However, our current understanding of these structures and how to control their properties is still limited due to their he...
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Published in | Analyst (London) Vol. 145; no. 7; pp. 2631 - 2638 |
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Main Authors | , , , |
Format | Journal Article |
Language | English |
Published |
England
Royal Society of Chemistry
07.04.2020
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Subjects | |
Online Access | Get full text |
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Summary: | Interphases formed at battery electrodes are key to enabling energy dense charge storage by acting as protection layers and gatekeeping ion flux into and out of the electrodes. However, our current understanding of these structures and how to control their properties is still limited due to their heterogenous structure, dynamic nature, and lack of analytical techniques to probe their electronic and ionic properties
in situ
. In this study, we used a multi-functional scanning electrochemical microscopy (SECM) technique based on an amperometric ion-selective mercury disc-well (HgDW) probe for spatially-resolving changes in interfacial Li
+
during solid electrolyte interphase (SEI) formation and for tracking its relationship to the electronic passivation of the interphase. We focused on multi-layer graphene (MLG) as a model graphitic system and developed a method for ion-flux mapping based on pulsing the substrate at multiple potentials with distinct behavior (
e.g.
insertion-deinsertion). By using a pulsed protocol, we captured the localized uptake of Li
+
at the forming SEI and during intercalation, creating activity maps along the edge of the MLG electrode. On the other hand, a redox probe showed passivation by the interphase at the same locations, thus enabling correlations between ion and electron transfer. Our analytical method provided direct insight into the interphase formation process and could be used for evaluating dynamic interfacial phenomena and improving future energy storage technologies.
Mapping correlated ion and electron transfer reactivity as a passivating battery interphase evolves. |
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Bibliography: | Electronic supplementary information (ESI) available: COMSOL simulations, and additional experimental data. See DOI 10.1039/c9an02637a ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 0003-2654 1364-5528 |
DOI: | 10.1039/c9an02637a |