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

## TL;DR

A new eco-friendly additive made from chitin improves the lifespan of zinc batteries by preventing anode damage and unwanted reactions.

## Contribution

A biomass-derived additive, 3A5AF, is introduced to enhance zinc anode stability in aqueous batteries.

## Key findings

- 3A5AF enables Zn||Zn symmetric cells to cycle for over 2700 hours at 1 mA cm−2.
- Zn||I2 full cells retained 93.9% capacity after 20,000 cycles at 8 A g−1.
- The additive suppresses dendrite growth, hydrogen evolution, and corrosion in zinc anodes.

## Abstract

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.

A biomass‐derived additive synthesized from chitin, 3‐acetylamino‐5‐acetylfuran (3A5AF), resolves key stability issues such as uncontrolled dendrite growth, hydrogen evolution reaction, and corrosion of zinc anodes by reconstructing the solvation structure of the electrolyte and protecting the anode interface.