Advanced PEI/PAN Membrane to Suppress Zinc Dendrite Growth in Zinc Metal Batteries

Aqueous zinc‐ion batteries (AZIBs) are a potential new technology in energy storage due to their high energy density, affordability, and environmental friendliness. Unchecked zinc dendrite formation during cycling still hinders the development of AZIBs, resulting in an unstable interface, a short cycling life, a considerable capacity decline, and security issues. Herein, we demonstrate a novel nanofiber membrane based on a polyethylenimine‐polyacrylonitrile (PEI‐PAN) polymer produced by electrospinning with entangled nanofibers for AZIBs applications. The as‐fabricated PEI/PAN membrane has a porous structure that is homogeneous, tortuous, and linked, with high porosity and superior electrolyte wettability. The PEI/PAN membrane has good thermal stability at 200 °C and high ionic conductivity of up to 5.3 x 10‐4 S cm−1. This membrane provides Zn/Zn symmetric cells with an ultralong cycle life of over 250 hours at 3 mA cm‐2. Additionally, MnO2/Zn cells outperforms commercial filter paper in terms of cycle stability and rate performance. This work demonstrates a simple technique for fabricating advanced nanofiber membranes for AZIBs to modify Zn2+ deposition behavior and improve Zn dendrite resistance.