Lignin-Derived Polyanionic Crosslinked Gel Interfacial Layer with Ion-Sieving and Ion-Regulating Capabilities for...

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 ─SO₃ ^- groups in the polyanionic gel optimize the Zn²⁺ solvent sheath structure while simultaneously providing ion-sieving function, which significantly facilitates Zn²⁺ 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 Zn²⁺ 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||NaV₃O₈·1.5H₂O 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.