Stable Zinc Anode Facilitated by Regenerated Silk Fibroin‐modified Hydrogel Protective Layer

Abstract

Inherent dendrite growth and side reactions of zinc anode caused by its unstable interface in aqueous electrolytes severely limit the practical applications of zinc‐ion batteries (ZIBs). To overcome these challenges, a protective layer for Zn anode inspired by cytomembrane structure is developed with PVA as framework and silk fibroin gel suspension (SFs) as modifier. This PVA/SFs gel‐like layer exerts similar to the solid electrolyte interphase, optimizing the anode‐electrolyte interface and Zn2+ solvation structure. Through interface improvement, controlled Zn2+ migration/diffusion, and desolvation, this buffer layer effectively inhibits dendrite growth and side reactions. The additional SFs provide functional improvement and better interaction with PVA by abundant functional groups, achieving a robust and durable Zn anode with high reversibility. Thus, the PVA/SFs@Zn symmetric cell exhibits an ultra‐long lifespan of 3150 h compared to bare Zn (182 h) at 1.0 mAh cm−2–1.0 mAh cm−2, and excellent reversibility with an average Coulombic efficiency of 99.04% under a large plating capacity for 800 cycles. Moreover, the PVA/SFs@Zn||PANI/CC full cells maintain over 20 000 cycles with over 80% capacity retention under harsh conditions at 5 and 10 A g−1. This SF‐modified protective layer for Zn anode suggests a promising strategy for reliable and high‐performance ZIBs.