Flat Zn deposition at battery anode via an ultrathin robust interlayer

Rechargeable aqueous zinc (Zn) ion batteries (AZIBs) using low-cost and safe Zn metal anodes are considered promising candidates for future grid-scale energy storage systems, but the Zn dendrite problem severely hinders the further prospects of AZIBs. Regulating Zn depositing behaviors toward horizontal alignment is highly effective and thus has received huge attention. However, such a strategy is usually based on previous substrate engineering, which requires complex preparation or expensive equipment. Therefore, it is essential to develop a novel solution that can realize horizontally aligned Zn flake deposition via easy operation and low cost. Herein, we report an ultrathin and robust Kevlar membrane as the interlayer to mechanically suppress Zn dendrite growth. Compared to the randomly distributed flaky dendrites in the control group, the deposited Zn sheets would grow into parallel alignment with the existence of such interlayer. As the dendrites are effectively suppressed, Zn||Cu asymmetric, Zn||Zn symmetric, and Zn||MnO₂ full batteries using Kevlar interlayer deliver significantly improved cycling stabilities. Furthermore, the Zn||MnO₂ pouch cell using a Kevlar interlayer delivers stable cycling performance and shows stable operation during multi-angle folding. We believe this work provides a new possibility for regulating Zn deposition from a crystallographic perspective.