Preventing Dissolution of Cathode Active Materials by Ion‐anchoring Zeolite‐based Separators for Durable Aqueous Zinc Batteries**

Abstract Aqueous zinc batteries have emerged as promising energy storage devices due to their safety and low cost. However, they face challenges such as anodic dendrite formation and cathodic compound dissolution. Here, we present the development of a polymer‐matrixed zeolite separator (SZ) by synthesizing zeolite materials on a flexible polymeric membrane. This separator acts as an effective ionic barrier, preventing the leaching and shuttling of vanadium from the cathode, while significantly inhibiting the formation of by‐products and zinc dendrites. The SZ cells demonstrate stable operation for more than 400 cycles at 0.5 A g −1 , with an initial capacity of 375.4 mAh g −1 , and over 10,000 cycles at 15 A g −1 . Notably, when pre‐anchored with vanadium ions, the SZ‐V cells exhibited excellent capacity retention of up to 94.6 % over 1000 cycles. The SZ separator featuring an ion barrier represents a crucial advancement towards the commercialization of zinc storage devices.