MoS2/Mayenite Electride Hybrid as a Cathode Host for Suppressing Polysulfide Shuttling and Promoting Kinetics in Lithium–Sulfur Batteries

Thatsami, Niphat; Tangpakonsab, Parinya; Sikam, Pornsawan; Hussain, Tanveer; Tamwattana, Orapa; Watcharapasorn, Anucha; Moontragoon, Pairot; Pathak, Biswarup; Kaewmaraya, Thanayut

doi:10.1021/acsami.4c05810

Author(s)

Thatsami, Niphat

Tangpakonsab, Parinya

Sikam, Pornsawan

Hussain, Tanveer

Tamwattana, Orapa

Watcharapasorn, Anucha

Moontragoon, Pairot

Pathak, Biswarup

Kaewmaraya, Thanayut

Publication Date

2024-07-24

Abstract

The commercial viability of emerging lithium−sulfur batteries (LSBs) remains greatly hindered by short lifespans caused by electrically insulating sulfur, lithium polysulfides (Li2Sn; 1 ≤ n ≤ 8) shuttling, and sluggish sulfur reduction reactions(SRRs). This work proposes the utilization of a hybrid composed of sulfiphilic MoS2 and mayenite electride (C12A7:e−) as a cathode host to address these challenges. Specifically, abundant cement-based C12A7:e− is the most stable inorganic electrode, possessing the ultimate electrical conductivity and low work function. Through density functional theory simulations, the key aspects of the MoS2/C12A7:e− hybrid including electronic properties, interfacial binding with Li2Sn, Li+ diffusion, and SRR have been unraveled. Our findings reveal the rational rules for MoS2 as an efficient cathode host by enhancing its mutual electrical conductivity and surface polarity via MoS2/C12A7:e−. The improved electrical conductivity of MoS2 is attributed to the electron donation from C12A7:e− to MoS2, yielding a semiconductor-to-metal transition. The resultant band positions of MoS2/C12A7:e− are well matched with those of conventional current-collecting materials (i.e., Cu and Ni), electrochemically enhancing the electronic transport. Theaccepted charge also intensifies MoS2 surface polarity for attracting polar Li2Sn by forming stronger bonds with Li2Sn via ionic Li−Sbonds than electrolytes with Li2Sn, thereby preventing polysulfide shuttling. Importantly, MoS2/C12A7:e− not only promotes rapid reaction kinetics by reducing ionic diffusion barriers but also lowers the Gibbs free energies of the SRR for effective S8-to-Li2Sconversion. Beyond the reported applications of C12A7:e−, this work highlights its functionality as an electrode material to boost the efficiency of LSBs.

Citation

ACS Applied Materials and Interfaces, 16(29), p. 37994-38005

Link

https://hdl.handle.net/1959.11/63779

Language

en

Publisher

American Chemical Society

Rights

Attribution-NonCommercial-NoDerivatives 4.0 International

Title

MoS2/Mayenite Electride Hybrid as a Cathode Host for Suppressing Polysulfide Shuttling and Promoting Kinetics in Lithium–Sulfur Batteries

Type of document

Journal Article

Entity Type

Publication

Author(s)	Thatsami, Niphat Tangpakonsab, Parinya Sikam, Pornsawan Hussain, Tanveer Tamwattana, Orapa Watcharapasorn, Anucha Moontragoon, Pairot Pathak, Biswarup Kaewmaraya, Thanayut
Publication Date	2024-07-24
Abstract	<p>The commercial viability of emerging lithium−sulfur batteries (LSBs) remains greatly hindered by short lifespans caused by electrically insulating sulfur, lithium polysulfides (Li<sub>2</sub>S<sub><i>n</i></sub>; 1 ≤ n ≤ 8) shuttling, and sluggish sulfur reduction reactions(SRRs). This work proposes the utilization of a hybrid composed of sulfiphilic MoS<sub>2</sub> and mayenite electride (C12A7:e<sup>−</sup>) as a cathode host to address these challenges. Specifically, abundant cement-based C12A7:e<sup>−</sup> is the most stable inorganic electrode, possessing the ultimate electrical conductivity and low work function. Through density functional theory simulations, the key aspects of the MoS<sub>2</sub>/C12A7:e<sup>−</sup> hybrid including electronic properties, interfacial binding with Li<sub>2</sub>S<sub><i>n</i></sub>, Li+ diffusion, and SRR have been unraveled. Our findings reveal the rational rules for MoS<sub>2</sub> as an efficient cathode host by enhancing its mutual electrical conductivity and surface polarity <i>via</i> MoS<sub>2</sub>/C12A7:e<sup>−</sup>. The improved electrical conductivity of MoS<sub>2</sub> is attributed to the electron donation from C12A7:e<sup>−</sup> to MoS<sub>2</sub>, yielding a semiconductor-to-metal transition. The resultant band positions of MoS<sub>2</sub>/C12A7:e<sup>−</sup> are well matched with those of conventional current-collecting materials (<i>i.e.</i>, Cu and Ni), electrochemically enhancing the electronic transport. Theaccepted charge also intensifies MoS<sub>2</sub> surface polarity for attracting polar Li<sub>2</sub>S<sub><i>n</i></sub> by forming stronger bonds with Li<sub>2</sub>S<sub><i>n</i></sub> <i>via</i> ionic Li−Sbonds than electrolytes with Li<sub>2</sub>S<sub><i>n</i></sub>, thereby preventing polysulfide shuttling. Importantly, MoS<sub>2</sub>/C12A7:e<sup>−</sup> not only promotes rapid reaction kinetics by reducing ionic diffusion barriers but also lowers the Gibbs free energies of the SRR for effective S<sub>8</sub>-to-Li<sub>2</sub>Sconversion. Beyond the reported applications of C12A7:e<sup>−</sup>, this work highlights its functionality as an electrode material to boost the efficiency of LSBs.</p>
Citation	ACS Applied Materials and Interfaces, 16(29), p. 37994-38005
Link	https://hdl.handle.net/1959.11/63779
Language	en
Publisher	American Chemical Society
Rights	Attribution-NonCommercial-NoDerivatives 4.0 International
Title	MoS2/Mayenite Electride Hybrid as a Cathode Host for Suppressing Polysulfide Shuttling and Promoting Kinetics in Lithium–Sulfur Batteries
Type of document	Journal Article
Entity Type	Publication

MoS2/Mayenite Electride Hybrid as a Cathode Host for Suppressing Polysulfide Shuttling and Promoting Kinetics in Lithium–Sulfur Batteries

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