Structure–Property of Lithium–Sulfur Nanoparticles via Molecular Dynamics Simulation

Journal Article · 08 October 2018 · ACS Applied Materials and Interfaces

DOI: https://doi.org/10.1021/acsami.8b09128 · OSTI ID:1476719

Li, Ying  ^[1]; Romero, Nichols A.; Lau, Kah Chun  ^[2]

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1. Argonne National Laboratory
2. Department of Physics & Astronomy, California State University, Northridge, Northridge, California 91330, United States

Lithium-sulfur (Li-S) batteries offer higher energy densities than most reported lithium-ion batteries. However, our understanding of Li-S battery is still largely unknown at the level of the nanoscale. Here, the structural properties of Li-S materials were investigated via molecular dynamics (MD) simulations using the ReaxFF force field. everal Li-S nanoparticles with different Li:S composition ratios (2:1 and 2:8) and various structures are studied. Our MD simulations show that, among the four structures we constructed for Li₂S₈ nanoparticles, the core-shell structure is the most thermodynamically stable one during the charging (delithiation) process. In contrast to bulk crystal Li₂S, we find the presence of mixed lithium sulfide and polysulfide species are common features for these Li-S (Li₂S, Li₂S₈) nanoparticles. The complex distribution of these sulfide and polysulfide speciation are dictated by both stoichiometry and local atomic structures in the nanoparticle. Finally, these findings will provide insight into further development of functionalized lithium-sulfur cathodes.

• Research Organization: Argonne National Lab. (ANL), Argonne, IL (United States); California State Univ., Northridge, CA (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Advanced Scientific Computing Research (ASCR)
• Grant/Contract Number: AC02-06CH11357
• OSTI ID: 1476719
• Journal Information: ACS Applied Materials and Interfaces, Journal Name: ACS Applied Materials and Interfaces Journal Issue: 43 Vol. 10; ISSN 1944-8244
• Publisher: American Chemical Society (ACS)Copyright Statement
• Country of Publication: United States
• Language: English