Title: Enhanced Stability of the Carba-closo-dodecaborate Anion for High-Voltage Battery Electrolytes through Rational Design

Abstract

Future energy applications rely on our ability to tune liquid intermolecular interactions and achieve designer electrolytes with highly optimized properties. In this work, we demonstrate rational, combined experimental-computational design of a new carba- closo-dodecaborate-based salt with enhanced anodic stability for Mg energy storage applications. We first establish, through a careful examination using a range of solvents, the anodic oxidation of a parent anion, the carba- closo-dodecaborate anion at 4.6 V vs Mg^0/2+ (2.0 vs Fc^0/+), a value lower than that projected for this anion in organic solvent-based electrolytes and lower than weakly associating bis(trifluoromethylsulfonyl)imide and tetrafluoroborate anions. Solvents such as acetonitrile, 3-methylsulfolane, and 1,1,1,3,3,3-hexafluoroisopropanol are shown to enable the direct measurement of carba-closo-dodecaborate oxidation, where the resultant neutral radical drives passive film formation on the electrode. Second, we employ computational screening to evaluate the impact of functionalization of the parent anion on its stability and find that replacement of the carbon-vertex proton with a more electronegative fluorine or trifluoromethyl ligand increases the oxidative stability and decreases the contact-ion pair formation energy while maintaining reductive stability. This predicted expansion of the electrochemical window for fluorocarba-closo-dodecaborate is experimentally validated. Future work includes evaluation of the viability of these derivative anions as efficientmore » and stable carriers for energy storage as a function of the ionic transport through the resulting surface films formed on candidate cathodes.« less

Authors:

Hahn, Nathan T.  ^[1];

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• Search DOE PAGES for ORCID "0000-0001-6187-4068"

Seguin, Trevor J. ^[2]; Lau, Ka-Cheong  ^[3];

• Search DOE PAGES for author "Lau, Ka-Cheong"
• Search DOE PAGES for ORCID "0000-0002-3726-163X"

Liao, Chen  ^[3];

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• Search DOE PAGES for ORCID "0000-0001-5168-6493"

Ingram, Brian J. ^[3]; Persson, Kristin A.  ^[4];

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• Search DOE PAGES for ORCID "0000-0003-2495-5509"

Zavadil, Kevin R.  ^[1]

• Search DOE PAGES for author "Zavadil, Kevin R."
• Search DOE PAGES for ORCID "0000-0002-3791-424X"

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+ Show Author Affiliations

1. Argonne National Lab. (ANL), Argonne, IL (United States). Joint Center for Energy Storage Research (JCESR); Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Materials, Physical and Chemical Sciences Center
2. Argonne National Lab. (ANL), Argonne, IL (United States). Joint Center for Energy Storage Research (JCESR); Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Energy Technologies Division
3. Argonne National Lab. (ANL), Argonne, IL (United States). Joint Center for Energy Storage Research (JCESR) and Chemical Sciences and Engineering Division
4. Argonne National Lab. (ANL), Argonne, IL (United States). Joint Center for Energy Storage Research (JCESR); Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Energy Technologies Division; Univ. of California, Berkeley, CA (United States). Dept. of Materials Science

Publication Date:

Mon Jul 30 00:00:00 EDT 2018

Research Org.:

Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Argonne National Laboratory (ANL), Argonne, IL (United States); Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)

Sponsoring Org.:

USDOE Office of Science (SC), Basic Energy Sciences (BES); USDOE National Nuclear Security Administration (NNSA)

OSTI Identifier:

1466987

Alternate Identifier(s):

OSTI ID: 1571108

Report Number(s):

SAND-2018-6418J
Journal ID: ISSN 0002-7863; 664406

Grant/Contract Number:  

AC04-94AL85000; NA0003525; AC02-05CH11231

Resource Type:

Accepted Manuscript

Journal Name:

Journal of the American Chemical Society

Additional Journal Information:

Journal Volume: 140; Journal Issue: 35; Journal ID: ISSN 0002-7863

Publisher:

American Chemical Society (ACS)

Country of Publication:

United States

Language:

English

Subject:

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; 25 ENERGY STORAGE; Magnesium; Multivalent; Electrochemistry; Weakly Coordinating; Electrochemical Window; Carborane, Sulfone; Glyme