Regulating Zinc Anode Interface with an Environmental Biomass‐Derived Additive for Long‐Lifespan Aqueous Batteries

Aqueous zinc-based batteries face critical stability issues at the zinc metal anode, primarily manifested as uncontrolled dendrite growth, hydrogen evolution reaction, and corrosion. To address these issues in an eco-friendly manner, we report a biomass-derived additive, 3-acetylamino-5-acetylfuran (3A5AF), synthesized from chitin, which features abundant polar N/O functional groups. Even at an ultralow concentration (0.3 mg mL^- ¹), 3A5AF could restructure the solvation shell of Zn² ⁺ and establish a protective layer on the anode surface, thereby curbing undesirable side reactions and guiding the uniform deposition of zinc. This stabilization strategy endows the Zn||Zn symmetric cell with robust longevity, achieving a cycle life exceeding 2700 h under 1 mA cm^- ² and 1 mAh cm^- ². Even when subjected to a demanding current density of 4 mA cm^- ², the cell maintains stable operation for 2400 h. The practical utility was further confirmed in Zn||I₂ full cells, which delivered a reversible capacity of 192.6 mAh g^-1 following 1000 cycles at 0.5 A g^- ¹ and, at 8 A g^- ¹, sustained 20 000 cycles with merely a 6.1% capacity loss (93.9% retention). This work highlights the promise of sustainable biomass-derived additives in developing high-performance and green aqueous zinc batteries.