As the installed capacity of clean energy continues to be expanded, the market demand for cost-effective energy storage technologies is growing. Against this backdrop, aqueous zinc-ion batteries (AZIBs) stand out for their high safety, low-cost, and environmentally friendly characteristics.

However, dendrite growth, interfacial corrosion, and hydrogen evolution side reactions occurring at the zinc metal anode cause a sharp decline in battery cycle life, which hinders the commercial application. How to construct a stable zinc anode interface and achieve uniform Zn²⁺ deposition/dissolution has become a challenge that needed to be addressed.

In a study published in Journal of Colloid and Interface Science, a research group led by Prof. ZHANG Yining from Fujian Institute of Research on the Structure of Matter of the Chinese Academy of Sciences developed a bifunctional gel coating (CG@Zn) that significantly stabilizes the zinc anode interface and greatly enhances the cycle life of AZIBs.

The newly developed bifunctional gel coating (CG@Zn) contains two components, sodium carboxymethyl cellulose (CMC) and glucose. Notably, the coating employs a water-based fabrication process, which eliminates toxic solvents, and its biodegradable raw materials align with green chemistry principles.

The coating regulates Zn²⁺ transport through the carboxyl groups in CMC molecules, promoting the uniform distribution of Zn²⁺ at the zinc anode interface and effectively inhibiting dendrite formation. Simultaneously, the hydroxyl-rich glucose molecules form hydrogen bonds to lock water molecules, significantly reducing the occurrence of hydrogen evolution reactions and enhancing the corrosion resistance of the zinc anode. 

The synergistic effect of CMC and glucose markedly improves the battery performance. At a current density of 5 mA cm^-2, symmetric cells with the CG@Zn coating demonstrated stable cycling for over 1,000 hours, which is five times longer than bare zinc anodes. Full cells paired with a NaV₃O₈·1.5H₂O cathode retained 67.1% capacity after 15,000 cycles at 10 A g^-1, far outperforming uncoated counterparts.

This study provides a safe, high-performance solution for grid-scale energy storage and wearable electronics. Researchers has developed a 1 Ah pouch cell prototype achieving 1C@300 cycles, demonstrating strong commercialization potential.