Enhancing lithium sulfide batteries with ZIF-8: Molecular dynamics simulation investigates separator and interlayer role

The role of ZIF-8 in Lithium sulfide batteries as a separator or interlayer was investigated through detailed molecular dynamics simulations. Two windows of ZIF-8 belonging to the [001] and [110] crystalline surfaces, known as ZIF-8A and ZIF-8B, respectively were examined in combination with the electrolyte. Trajectory and mean square displacement (MSD) analysis revealed that despite the presence of an electrical field, none of the electrolyte species could pass through the channel of ZIF-8A. However, lithium ions were observed to undergo migration from the ZIF-8B channels. The diffusion of species within the electrolyte increased with temperature, while, it was irregular in the presence of ZIF-8. Furthermore, radial distribution function (RDF) and coordination number plots showed an increased distance and weaker interaction between lithium ions and polysulfides in the presence of ZIF-8, with the interaction between lithium and nitrogen atoms of ZIF-8B being stronger than that of ZIF-8A. Results conclude that ZIF-8B can be utilized as an interlayer or cathode layer to decrease the shuttle effect in Li-S batteries.