Title: Structure and Dynamics of Polysulfide Clusters in a Nonaqueous Solvent Mixture of 1,3-Dioxolane and 1,2-Dimethoxyethane

Abstract

© 2019 American Chemical Society. Molecular clustering and associated dynamic processes of lithium polysulfide species were unraveled using classical molecular dynamics and ab initio metadynamics calculations. The spectroscopic signatures of polysulfide clusters were analyzed using a multimodal analysis including experimental and computational nuclear magnetic resonance (NMR) and X-ray absorption spectroscopies. Lithium polysulfide solutes (Li2S4, Li2S6, and Li2S8) and their mixtures in a 1,3-dioxolane and 1,2-dimethoxyethane (DOL/DME) solvent undergo aggregation driven by intramolecular lithium-sulfur (Li-S) interactions, leading to distributions of cluster sizes, which could critically influence the functioning of lithium-sulfur batteries. Representative polysulfide clusters with systematic increases in molecular size were extracted from the classical molecular dynamics trajectories for subsequent structural and spectroscopic property calculations using density functional theory analysis. Structural analysis of these clusters reveals progressively decreasing solvent involvement in Li+ coordination varying from Li2S4 to Li2S8, with more pronounced variation and changes in DME compared with those in DOL. These observations are reflected in the analysis of the experimental and theoretical 7Li and 17O NMR chemical shifts and pulsed field gradient-NMR diffusion measurements. A comparison of experimental and theoretical S K-edge X-ray absorption near edge spectra shows that relatively large lithium sulfide chain clusters are likely to occur inmore » the DOL/DME-solvated lithium sulfide systems. Ab initio metadynamics simulations and NMR analysis indicate that Li+ solvated by only the solvent can occur through Li+ dissociation from sulfide chains. However, the occurrence of "sulfide-free" Li+ is a minor mechanism compared with the dynamic aggregation and shuttling processes of polysulfide solvates in DOL/DME-based electrolytes of Li-S batteries. Overall, atomistic insights gained about clustering and lithium exchange dynamics will be critical for the predictive understanding of the polysulfide shuttling and nucleation process that dictates the Li-S battery performance.« less

Authors:

Andersen, Amity  ^[1];

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• Search DOE PAGES for ORCID "0000-0002-6529-0905"

Rajput, Nav Nidhi  ^[2];

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• Search DOE PAGES for ORCID "0000-0003-4740-8217"

Han, Kee Sung  ^[3];

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Pan, Huilin ^[3]; Govind, Niranjan  ^[1];

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• Search DOE PAGES for ORCID "0000-0003-3625-366X"

Persson, Kristin A.  ^[4];

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

Mueller, Karl T.  ^[3];

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• Search DOE PAGES for ORCID "0000-0001-9609-9516"

Murugesan, Vijayakumar  ^[3]

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• Search DOE PAGES for ORCID "0000-0001-6149-1702"

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+ Show Author Affiliations

1. Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
2. Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Joint Center for Energy Storage Research (JCESR), Lemont, IL (United States)
3. Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Joint Center for Energy Storage Research (JCESR), Lemont, IL (United States)
4. Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Univ. of California, Berkeley, CA (United States); Joint Center for Energy Storage Research (JCESR), Lemont, IL (United States); Joint Center for Energy Storage Research (JCESR), Lemont, IL (United States)

Publication Date:

Fri Feb 15 00:00:00 EST 2019

Research Org.:

Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). National Energy Research Scientific Computing Center (NERSC); Argonne National Lab. (ANL), Argonne, IL (United States). Joint Center for Energy Storage Research (JCESR); Pacific Northwest National Lab. (PNNL), Richland, WA (United States). Environmental Molecular Sciences Lab. (EMSL)

Sponsoring Org.:

USDOE Office of Science (SC), Basic Energy Sciences (BES); USDOE Office of Science (SC), Biological and Environmental Research (BER); USDOE Laboratory Directed Research and Development (LDRD) Program; National Research Council Canada (NRC)

OSTI Identifier:

1529348

Alternate Identifier(s):

OSTI ID: 1530600; OSTI ID: 1769304

Report Number(s):

PNNL-SA-141178
Journal ID: ISSN 0897-4756

Grant/Contract Number:  

AC02-06CH11357; AC02-05CH11231; AC05-76RL01830; AC02-05CH1123

Resource Type:

Accepted Manuscript

Journal Name:

Chemistry of Materials

Additional Journal Information:

Journal Volume: 31; Journal Issue: 7; Journal ID: ISSN 0897-4756

Publisher:

American Chemical Society (ACS)

Country of Publication:

United States

Language:

English

Subject:

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY