Advances and perspectives on separators of aqueous zinc ion batteries

With the advantages of intrinsic safety, good affordability, environmental friendliness, moderate energy density, and large power density, aqueous zinc ion batteries (AZIBs) have gained considerable research interest. However, zinc dendrites, hydrogen evolution, inert byproducts, and zinc metal corrosion severely hinder practical applications of AZIBs. In order to address these issues, many research works have been carried out to modify the interface between zinc metal anode and aqueous electrolyte. In fact, the interface engineering takes effect at the surface and near the surface of separator. However, a specialized review on the separators of AZIBs is still lacking. Herein, basic requirements of separators and recent advances on the modification strategies including employment of functional groups, establishment of surface coatings, construction of hybrid architectures, regulations of porosity, and utilization of bipolar membrane are reviewed. Besides, the perspectives for further investigations on the separators of AZIBs are outlined. This review could offer useful guidance for the future explorations of separators for AZIBs.