Enhancing Zinc Anode Reversibility through Dynamic Interface Engineering with Monolayer Hydrophobic Carbon Dots

Area of Science:

• Electrochemistry
• Materials Science
• Energy Storage

Background:

• Aqueous zinc-ion batteries (AZIBs) offer a low-cost and safe alternative for grid storage.
• Poor zinc anode reversibility, caused by dendrite formation and water-induced side reactions, limits AZIB practical application.

Purpose of the Study:

• To enhance the reversibility and stability of zinc anodes in AZIBs.
• To suppress water-induced side reactions and dendrite formation at the electrode/electrolyte interface.

Main Methods:

• Dynamically constructing a monolayer of hydrophobic carbon dots (CDs) at the electrode/electrolyte interface.
• Utilizing trace amounts of hydrophobic CDs in the electrolyte to modify the electric double layer (EDL) structure.
• Investigating the interfacial behavior during zinc ion plating.

Main Results:

• The hydrophobic CD monolayer reconstructed a favorable EDL structure, suppressing side reactions and facilitating zinc ion desolvation.
• The dynamic interfacial integrity was maintained during zinc plating, preventing dendrite growth.
• Zn symmetric cells demonstrated extended lifespans up to 2400 h at 10 mA cm⁻² and 600 h at 30 mA cm⁻².
• Full cells (coin and pouch types) exhibited exceptional stability.

Conclusions:

• The dynamic monolayer protective interface strategy is effective for reversible metal anodes.
• Hydrophobic CDs offer a promising approach to overcome key challenges in aqueous zinc-ion battery technology.