Separators for Aqueous Zinc‐Ion Batteries

The essential function of a separator is to prevent the physical contact of electrodes while serving as the electrolyte reservoir to enable ion transport. This chapter discusses the main performance requirements of the separator for aqueous zinc-ion batteries (AZIBs) and describes the relevant separator properties that meet the good performance of the separator. The chemical stability of the separator mainly refers to the corrosion resistance and dimensional stability of the electrolyte. The chapter introduces some common and commercial separators used in AZIBs. Gel electrolytes (GEs) and solid electrolytes (SEs) can be regarded as a combination of separator and electrolyte with both ion transport and mechanical barrier functions, which is classified as separator-free type. The development of high-performance GEs and SEs is of great significance in promoting the development and application of AZIBs. Separators for AZIBs mostly refer to commercialized lithium-ion batteries separators and have their own inherent defects.