A Novel Strategy for the Selection of Polysulfide Adsorbents Toward High-Performance Lithium-Sulfur Batteries

Selection of polysulfide adsorbents for most lithium-sulfur batteries (LSBs) has only one purpose, which is to suppress the shuttle effect. However, addition of the polysulfides adsorbents inevitably reduces the energy density of LSBs. In this article, a new idea to select a polar cathode material whose discharge-charge voltage coincides with sulfur is proposed. It can adsorb polysulfides and provides part of capacity in the discharge of LSBs. TiO2 is used as an example to prove the feasibility of such an idea, and prepares a sandwich structure cathode via a simple method. In situ X-ray diffraction is carried out to directly monitor the structural changes of the sandwich-structured cathode during the discharge-charge processes. The experimental data verify the idea and the work provides a new strategy for the selection of polysulfide adsorbents in the future.