Anisotropically Hybridized Porous Crystalline Li‐S Battery Separators

Abstract Anisotropically hybridized porous crystalline Li‐S battery separators based on porous crystalline materials that can meet the multiple functionalities of both anodic and cathodic sides are much desired for Li‐S battery yet still challenging in directional design. Here, an anisotropically hybridized separator (CPM) based on an ionic liquid‐modified porphyrin‐based covalent‐organic framework (COF‐366‐OH‐IL) and catalytically active metal‐organic framework (Ni 3 (HITP) 2 ) that can integrate the lithium‐polysulfides (LiPSs) adsorption/catalytic conversion and ion‐conduction sites together to directionally meet the requirements of electrodes is reported. Remarkably, the‐obtained separator exhibits an exceptional high Li + transference‐number ( t Li+ = 0.8), ultralow polarization‐voltage (<30 mV), high initial specific‐capacity (921.38 mAh g −1 at 1 C), and stable cycling‐performance, much superior to polypropylene and monolayer‐modified separators. Moreover, theoretical calculations confirm the anisotropic effect of CPM on the anodic side (e.g., Li + transfer, LiPSs adsorption, and anode‐protection) and cathodic side (e.g., LiPSs adsorption/catalysis). This work might provide a new perspective for separator exploration.