Functionalized Separator Strategies toward Advanced Aqueous Zinc‐Ion Batteries

Abstract Aqueous zinc‐ion batteries (ZIBs) enjoy a good reputation for being safe, affordable to produce, and ecologically friendly due to the use of water‐based electrolytes. The main factors restricting the development of ZIBs, however, are the negative effects of dendrite deposition on the zinc anode and the dissolution of common cathodes such as Mn and V‐based cathodes. Various techniques have been used to address these issues, including regulating the electrolyte concentration or solvation structure, developing a coating or current collector to lessen anode dendrite growth, and improving the structural stability of the cathode. Recently, functionalized separator strategies have gained popularity as effective ways to improve ZIB performance. The use of a functionalized separator is also a practical technique to save costs and increase the volumetric energy density of the battery by substituting a functionalized separator for the usual thick and expensive glass fiber separator. The development of functionalized separators in ZIBs is the subject of ongoing research, and this work presents the most recent findings in a systematic manner, focusing on both the effects and the methods to prepare or modify them. Finally, a brief explanation of the constraints and future potential of current functionalized separator development is provided.