Constructing amphipathic molecular layer to assists de-solvation process for dendrite-free Zn anode

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Aqueous Zn-ion batteries (AZIBs) are promising due to safety and resource availability.
• Zinc dendrite growth and side reactions on the zinc surface hinder AZIB performance.

Purpose of the Study:

• To develop a strategy to suppress dendrite formation and side reactions in AZIBs.
• To improve the cycling stability and lifespan of AZIBs.

Main Methods:

• Constructing an amphipathic molecular layer of Polyacrylic Acid (PAA) on the zinc surface.
• Investigating the effect of PAA on the de-solvation process and zinc deposition using electrochemical methods.
• Testing Zn||Zn symmetric cells with PAA additive in ZnSO4 electrolyte.

Main Results:

• The amphipathic PAA layer lowers the de-solvation energy barrier, inhibiting water decomposition and side reactions.
• PAA promotes homogeneous zinc deposition through interfacial negative charge accumulation.
• Zn||Zn symmetric cells demonstrated superior cycling stability of 4643 hours at 5 mA cm⁻² and 1 mAh cm⁻².

Conclusions:

• Amphipathic molecular layers offer a novel approach to stabilize the zinc anode in AZIBs.
• PAA effectively mitigates dendrite growth and side reactions, paving the way for long-life AZIBs.
• This study provides critical insights for designing advanced aqueous zinc-ion battery systems.