Issue 5, 2018

Interaction between functionalized graphene and sulfur compounds in a lithium–sulfur battery – a density functional theory investigation

Abstract

Lithium–sulfur (Li–S) batteries are emerging as one of the promising candidates for next generation rechargeable batteries. However, dissolution of lithium polysulfides in the liquid electrolyte, low electrical conductivity of sulfur and large volume change during electrochemical cycling are the main technical challenges for practical applications. In this study, a systematic first-principles density functional theory calculation is adopted to understand the interactions between graphene and graphene with oxygen containing functional groups (hydroxyl, epoxy and carboxyl groups) and sulphur (S8) and long chain lithium polysulfides (Li2S8 and Li2S4). We find the adsorption is dominated by different mechanisms in sulphur and lithium polysulfides, i.e. van der Waals attraction and formation of coordinate covalent Li–O bonds. The adsorption strength is dependent on the inter-layer distance and electron rich functional groups. Through these mechanisms, sulphur and lithium polysulfides can be successfully retained in porous graphene, leading to improved conductivity and charge transfer in the cathode of Li–S batteries.

Graphical abstract: Interaction between functionalized graphene and sulfur compounds in a lithium–sulfur battery – a density functional theory investigation

Supplementary files

Article information

Article type
Paper
Submitted
21 oct. 2017
Accepted
27 déc. 2017
First published
09 janv. 2018
This article is Open Access
Creative Commons BY license

RSC Adv., 2018,8, 2271-2279

Interaction between functionalized graphene and sulfur compounds in a lithium–sulfur battery – a density functional theory investigation

K. C. Wasalathilake, M. Roknuzzaman, K. (. Ostrikov, G. A. Ayoko and C. Yan, RSC Adv., 2018, 8, 2271 DOI: 10.1039/C7RA11628D

This article is licensed under a Creative Commons Attribution 3.0 Unported Licence. You can use material from this article in other publications without requesting further permissions from the RSC, provided that the correct acknowledgement is given.

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