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Conditioning-Free Mg Electrolyte by the Minor Addition of Mg(HMDS)₂

Kim, Seong Shik and Bevilacqua, Sarah C. and See, Kimberly A. (2020) Conditioning-Free Mg Electrolyte by the Minor Addition of Mg(HMDS)₂. ACS Applied Materials & Interfaces, 12 (5). pp. 5226-5233. ISSN 1944-8244. https://resolver.caltech.edu/CaltechAUTHORS:20191212-105210844

[img] PDF (Water content of electrolytes, Coulombic efficiency profile of MACC + 10 mM Mg(HMDS)₂, and cycling evolution of as-prepared MACC + 5 mM Mg(HMDS)₂ with varying water contents and after aging) - Supplemental Material
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Abstract

Mg-based batteries are an attractive next-generation energy storage chemistry due to the high natural abundance and inexpensive cost of Mg, along with the high theoretical energy density compared to that of conventional Li-ion chemistry. The greater energy density is predicated on a Mg metal anode, and pathways to achieving reversible Mg electrodeposition and stripping are reliant on the development of Mg electrolytes. Although Mg electrolyte chemistry has advanced significantly from the reactive Grignards of the 1920s to the carboranes of this decade, there remains significant challenges in correlating the Mg metal anode electrochemistry with the composition of the electrolyte salts as a result of the complicated interface of Mg metal and the electrolyte. To probe the effect of the interface on Mg electrodeposition, we turn to an electrolyte with a known solution-phase composition: the magnesium aluminum chloride complex (MACC) electrolyte. The MACC electrolyte requires electrolytic conditioning to support reversible Mg electrodeposition and stripping. Here, we show that a small concentration (2–5 mM) of Mg(HMDS)₂ with respect to the MACC electrolyte salts suppresses Al³⁺ deposition and promotes reversible Mg electrodeposition and stripping in the first cycle. The significant effect of a small concentration of additive is attributed to changes to the electrode interface. The impact of the Mg interface on the observed electrochemical performance is discussed.


Item Type:Article
Related URLs:
URLURL TypeDescription
https://doi.org/10.1021/acsami.9b16710DOIArticle
ORCID:
AuthorORCID
Kim, Seong Shik0000-0003-2604-6392
Bevilacqua, Sarah C.0000-0002-6834-7145
See, Kimberly A.0000-0002-0133-9693
Additional Information:© 2019 American Chemical Society. Received: September 15, 2019; Accepted: November 27, 2019; Published: December 11, 2019. Special Issue: Young Investigator Forum. S.C.B. acknowledges a graduate fellowship from the Resnick Sustainability Institute at Caltech. The authors declare no competing financial interest.
Group:Resnick Sustainability Institute
Funders:
Funding AgencyGrant Number
Resnick Sustainability InstituteUNSPECIFIED
Subject Keywords:magnesium electrolyte; magnesium electrodeposition; electrolyte speciation; conditioning-free electrolyte
Issue or Number:5
Record Number:CaltechAUTHORS:20191212-105210844
Persistent URL:https://resolver.caltech.edu/CaltechAUTHORS:20191212-105210844
Official Citation:Conditioning-Free Mg Electrolyte by the Minor Addition of Mg(HMDS)2. Seong Shik Kim, Sarah C. Bevilacqua, and Kimberly A. See. ACS Applied Materials & Interfaces 2020 12 (5), 5226-5233; DOI: 10.1021/acsami.9b16710
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:100275
Collection:CaltechAUTHORS
Deposited By: George Porter
Deposited On:16 Dec 2019 15:42
Last Modified:06 Feb 2020 18:37

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