Interfacial Engineering of Polymer Membranes with Intrinsic Microporosity for Dendrite-Free Zinc Metal Batteries

Metallic zinc has emerged as a promising anode material for high-energy battery systems due to its high theoretical capacity (820 mAh g^-1), low redox potential for two-electron reactions, cost-effectiveness and inherent safety. However, current zinc metal batteries face challenges in low coulombic efficiency and limited longevity due to uncontrollable dendrite growth, the corrosive hydrogen evolution reaction (HER) and decomposition of the aqueous ZnSO₄ electrolyte. Here, we report an interfacial-engineering approach to mitigate dendrite growth and reduce corrosive reactions through the design of ultrathin selective membranes coated on the zinc anodes. The submicron-thick membranes derived from polymers of intrinsic microporosity (PIMs), featuring pores with tunable interconnectivity, facilitate regulated transport of Zn²⁺-ions, thereby promoting a uniform plating/stripping process. Benefiting from the protection by PIM membranes, zinc symmetric cells deliver a stable cycling performance over 1500 h at 1 mA/cm² with a capacity of 0.5 mAh while full cells with NaMnO₂ cathode operate stably at 1 A g^-1 over 300 cycles without capacity decay. Our work represents a new strategy of preparing multi-functional membranes that can advance the development of safe and stable zinc metal batteries.