Title: Structural Dependence of the Sulfur Reduction Mechanism in Carbon-Based Cathodes for Lithium–Sulfur Batteries

Abstract

We report lithium-sulfur batteries are promising non-conventional sources of energy due to their high theoretical capacity and energy density. However, the successful implementation of this technology has been hindered due to the low cycling life of the battery, caused by long chain polysulfide shuttling between electrodes during charge/discharge, among other issues. Quantum chemical calculations are used to study the reactivity of sulfur in the porous cathode of lithium-sulfur batteries, and the retention capabilities of porous carbon materials to avoid long chain polysulfide diffusion. Ab initio molecular dynamics (AIMD) simulations are initially employed to evaluate sulfur reduction mechanisms and kinetics, and to identify main reduction products. A porous cathode architecture is modeled through parallel graphene layers with elemental sulfur rings in the interlayer, and filled with 1,3-dioxolane (DOL) organic solvent and lithium ions. AIMD simulations showed fast reduction of elemental sulfur and formation of short chain polysulfide. Furthermore, the effect of dangling carbon bonds of graphene on the reactivity of the cathode was confirmed. Adsorption calculations through density functional theory (DFT) proved the capacity of small pores to retain long polysulfide chains. An analysis of the effect of the specific current on the chemical behavior of sulfur reveals an influence ofmore » current on the amount of sulfur utilization and practical specific capacity of the battery. In conclusion, this work illustrates the physical-chemical behavior of the sulfur/polysulfide in the porous cathode system at atomistic level.« less

Authors:

Burgos, Juan C.  ^[1];

• Search DOE PAGES for author "Burgos, Juan C."
• Search DOE PAGES for ORCID "0000-0001-6576-8553"

Balbuena, Perla B.  ^[2];

• Search DOE PAGES for author "Balbuena, Perla B."
• Search DOE PAGES for ORCID "0000-0002-2358-3910"

Montoya, Javier A.  ^[3]

• Search DOE PAGES for author "Montoya, Javier A."
• Search DOE PAGES for ORCID "0000-0003-0507-452X"

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+ Show Author Affiliations

1. Univ. of Cartagena (Colombia). Doctorate in Physical Sciences. Faculty of Exact and Natural Sciences; Texas A & M Univ., College Station, TX (United States). Dept. of Chemical Engineering
2. Texas A & M Univ., College Station, TX (United States). Dept. of Chemical Engineering
3. Univ. of Cartagena (Colombia). Doctorate in Physical Sciences. Faculty of Exact and Natural Sciences. Inst. of Applied Mathematics

Publication Date:

Thu Aug 17 00:00:00 EDT 2017

Research Org.:

Texas A & M Univ., College Station, TX (United States). Texas A & M Engineering Experiment Station

Sponsoring Org.:

USDOE Office of Energy Efficiency and Renewable Energy (EERE), Vehicle Technologies Office (EE-3V)

OSTI Identifier:

1430484

Grant/Contract Number:  

EE0006832

Resource Type:

Accepted Manuscript

Journal Name:

Journal of Physical Chemistry. C

Additional Journal Information:

Journal Volume: 121; Journal Issue: 34; Journal ID: ISSN 1932-7447

Publisher:

American Chemical Society

Country of Publication:

United States

Language:

English

Subject:

25 ENERGY STORAGE; 36 MATERIALS SCIENCE