Improved Strategies for Separators in Zinc-Ion Batteries

The demand for energy storage is growing, and the disadvantages of lithium-ion batteries are being explored to overcome them. Accordingly, aqueous zinc-ion batteries (ZIBs) are developing very rapidly, owing to their high safety, environmental friendliness, high abundance of resources, and high cost performance. Over the last decade, ZIBs have made remarkable progress through extensive efforts in the field of electrode materials and through fundamental understanding of non-electrode components, such as solid-electrolyte interphase, electrolytes, separators, binders, and current collectors. In particular, the breakthrough in using separators on non-electrode elements should not be overlooked as such separators have proven key to conferring ZIBs with high energy and power density. In this Review, recent progress in the development of separators in ZIBs is comprehensively summarized based on their functions and roles in ZIBs, including the modification of conventional separators and the development of novel separators. Finally, the prospects and future challenges of separators are also discussed to facilitate ZIBs development.