Structural Properties and Ion Diffusion Pathways in Molybdenum Sulfide Materials of Interest for Li-S Batteries

Rechargeable battery systems, such as lithium-sulfur batteries, have garnered significant attention due to their high specific energies, lightweight form factors, and cost. However, challenges such as polysulfide shuttling and limited recharge cycles remain as shortcomings. Molybdenum sulfide-based chalcogels demonstrate potential to address these limitations as they show enhanced kinetics of lithium diffusion and the ability to mitigate polysulfide shuttling in lithium-sulfur (Li-S) systems. Here we are interested in developing structure–function relationships of molybdenum sulfide structures identified in the chalcogels through density functional theory (DFT) calculations and first-principles molecular dynamics simulations. We explore diverse sampling trajectories to extract structural factors, pair distribution functions, and bond structures to identify models that closely align with experiment. We then aim to elucidate ion diffusion pathways within the different molybdenum sulfide structures. The results of these studies provide fundamental understanding of the relationships among the composition, structure, and ion diffusion pathways in molybdenum sulfide-based chalcogels with the goal of delivering insights for future materials development.