Tailoring carbon shell thickness in graphene–Li2S–carbon nanocomposite cathodes for enhanced polysulfide control and electrochemical stability

Sep 30, 2026

Lithium–sulfur batteries face performance limits from low electrical/ionic conductivity of Li2S and the dissolution of intermediate polysulfides that trigger the shuttle effect and degrade cycling. A multiphysics simulation in COMSOL Multiphysics analyzes how carbon shell thickness (0–20 nm) in graphene–Li2S–carbon nanocomposite cathodes affects electrochemical, thermal, and ionic behavior under experimentally realizable conditions (1C, 35 °C). Heat transfer, ion transport, and current conservation are validated against reported voltage–capacity data with low RMSE (0.09 V). Results show ~10 nm provides the best balance: stronger polysulfide confinement, minimized temperature rise, reduced ionic resistance, and improved current-density uniformity, offering a predictive design framework grounded in experiments.

LanguageEnglish

CategoryResearch & Report

FormatPDF

Pages12

Reading Time30 min

AccessFree to download

Introduction

Carbon-shell design background

Modeling approach and validation

Results: optimal thickness and performance gains

RSC Advances PAPER Cite this: RSC Adv., 2026, 16, 2229 Received 8th October 2025 Accepted 27th December 2025 DOI: 10.1039/d5ra07689g [rsc.li/rsc-advances](rsc.li/rsc-advances) Tailoring carbon shell thickness in graphene–Li2S– carbon nanocomposite cathodes for enhanced polysulﬁde control and electrochemical stability Farag M. A. Altalbawy,a I. B. Sapaev, bcde Fadel F. Saied,f Paul Rodrigues,g Rekha M. M., h Laxmidhar Maharana,i P. Grace Kanmani Prince,jn Gaganjot Kaur,k Malik Bader Alazzaml and Shayan Amiri *m Lithium–sulfur (Li–S) batteries are promising next-generation energy storage systems due to their high theoretical energy density and the abundance of sulfur; however, their practical application is severely limited by the poor electrical and ionic conductivity of Li2S and the dissolution of intermediate polysulﬁdes. In this work, a comprehensive multiphysics simulation study is conducted to investigate the inﬂuence of carbon shell thickness (0–20 nm) on the electrochemical, thermal, and ionic performance of graphene–Li2S–carbon nanocomposite cathodes under experimentally realizable conditions (1C discharge rate and 35 °C) . The model, developed using COMSOL Multiphysics, couples heat transfer, ion transport, and electric current conservation to capture the complex interactions governing cathode behavior. To ensure experimental relevance and reliability, the simulation results are rigorously validated against reported experimental voltage–capacity data for graphene–Li2S–carbon cathodes, achieving a low root mean square error of 0 . 09 V. The results reveal that a carbon shell thickness of approximately 10 nm provides an optimal balance between polysulﬁde conﬁnement and lithium-ion transport, leading to minimized temperature rise, reduced ionic resistance, and improved current-density uniformity. By establishing a quantitative agreement with experimental literature, this study oﬀers a predictive and experimentally grounded framework for the rational design and optimization of high-performance Li–S battery cathodes. aRenewable Energy and Environmental Technology Center, University of Tabuk, Tabuk, Saudi Arabia bHead of the Department of Physics and Chemistry, Tashkent Institute of Irrigation and Agricultural Mechanization Engineers, National Research University, Tashkent, Uzbekistan cScienti􀀁c Researcher of the University of Tashkent for Applied Science, Uzbekistan dSchool of Engineering, Central Asian University, Tashkent 111221, Uzbekistan e Western Caspian University, Scienti􀀁c Researcher, Baku, Azerbaijan fDepartment of Chemistry, College of Chemistry, The Islamic University, Najaf, Iraq gDepartment of Computer Engineering, College of Computer Science, King Khalid University, Al-Faraa, Kingdom of Saudi Arabia hDepartment of Chemistry and Biochemistry, School of Sciences, JAIN (Deemed to Be University), Bangalore, Karnataka, India iDepartment of Pharmaceutical Sciences, Siksha ‘O ’ Anusandhan (Deemed to Be University), Bhubaneswar, Odisha-751030, India jDepartment of Biomedical, Sathyabama Institute of Science and Technology, Chennai, Tamil Nadu, India kDepartment of Electronics and Communication Engineering, Chandigarh University, Mohali, Punjab, India lFaculty of Information Technology, Jadara University, Irbid, Jordan m Young Researchers and Elite Club, Tehran University, Tehran, Iran. E-mail: sh. [amiriacademic@gmail.com](amiriacademic@gmail.com) nSharda School of Engineering and Science, Sharda University, Greater Noida, UP, India 1. Introduction Lithium–sulfur (Li–S) batteries are a promising energy storage technology due to their high theoretical energy density of 2600 Wh kg −1, far surpassing conventional lithium-ion batteries, and the use of sulfur, which is abundant, low-cost, and environmentally friendly.1,2 These attributes make Li–S batteries attractive for applications like electric vehicles and grid storage. However, their practical deployment is challenged by se

FAQs

What problem limits lithium–sulfur batteries in practice?

Low electrical and ionic conductivity of Li2S and dissolution of intermediate polysulfides cause the shuttle effect, leading to active material loss, parasitic reactions, and faster degradation of capacity and cycle life.

What does the study simulate, and what parameter is varied?

The study uses COMSOL Multiphysics to couple heat transfer, ion transport, and electric current conservation while varying carbon shell thickness from 0 to 20 nm in graphene–Li2S–carbon nanocomposite cathodes.

How are the simulation results validated?

Simulation outputs are rigorously compared with reported experimental voltage–capacity data for graphene–Li2S–carbon cathodes, achieving a low root mean square error of 0.09 V.

Why is an approximately 10 nm carbon shell thickness considered optimal?

It balances polysulfide confinement and lithium-ion transport, producing minimized temperature rise, lower ionic resistance, and improved current-density uniformity while reducing polysulfide leakage.

Sep 30, 2026

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