Research on the adsorption mechanism and the effect of sulfur-inhibiting shuttle of lithium polysulfides on Mn3O4 for lithium-sulfur batteries

The shuttle effect of lithium polysulfides poses a significant challenge to the practical application of lithium-sulfur batteries. When the adsorption energy of a material is greater than that in the solvent, the anchoring effect of the material inhibits the shuttle effect. In this study, first-principles calculations were employed to investigate the ion-relaxation and electronic structures of the adsorption material Mn₃O₄, Li₂S_x molecules, and the surface model of Li₂S_x adsorption on Mn₃O₄. The mechanism of Mn₃O₄ adsorption to Li₂S_x molecules and its role in inhibiting the sulfur shuttle were elucidated through the analysis of adsorption energies, changes in Li-O and S-Mn bonds during the adsorption process, and the charge transfer between Li₂S_x molecules and surface atoms. The comprehensive analysis conducted at molecular, atomic, and electronic levels provides valuable insights into the adsorption process. It was observed that O and Mn sites co-adsorb at both long and short bridge sites, with the long bridge sites demonstrating higher effectiveness in adsorbing Li₂S_x. The study proposes that incorporating Mn₃O₄ into the battery separator can effectively adsorb Li₂S_x, thereby suppressing the shuttle effect, owing to the robust Li-O and S-Mn interactions identified in the analysis. This approach holds promise for enhancing the performance of lithium-sulfur batteries by mitigating the detrimental impact of the shuttle effect.