Lignin‐Derived Polyanionic Crosslinked Gel Interfacial Layer with Ion‐Sieving and Ion‐Regulating Capabilities for Dendrite‐Free Zinc Anodes

Abstract The severe side reactions and rampant dendrite growth on the zinc (Zn) electrode significantly hinder the practical applications of aqueous zinc‐ion batteries (AZIBs). Herein, we fabricate a multifunctional interfacial layer composed of polyvinylidene difluoride (PVDF) and polyanionic gel featuring ion‐sieving and ion‐regulating capabilities that effectively protects the Zn anode. The abundant ─SO 3 − groups in the polyanionic gel optimize the Zn 2+ solvent sheath structure while simultaneously providing ion‐sieving function, which significantly facilitates Zn 2+ migration. The lignin derivatives are pre‐adsorbed onto the Zn anode surface, directing nucleation along the Zn (002) plane and offering electrostatic shielding effects to facilitate uniform Zn 2+ deposition. Additionally, the polyanionic gel inhibits water activity by forming strong hydrogen bonds with water, while the PVDF layer adjacent to Zn electrode significantly reduces water‐induced side reactions. Consequently, the Zn electrodes incorporating this protective layer demonstrated stable and efficient deposition/stripping behaviors across a wide range of current densities. The Zn||NaV 3 O 8 ·1.5H 2 O full cells demonstrate remarkable cycling stability, maintaining the capacity of 176.1 mAh g −1 after 1000 cycles at 5 A g −1 and 101.2 mAh g −1 after 2500 cycles at 10 A g −1 . This innovative strategy presents a promising approach to the development of high‐performance AZIBs.