Structure-Controlled Carbon Hosts for Dendrite-Free Aqueous Zinc Batteries.

Area of Science:

• Electrochemistry
• Materials Science
• Energy Storage

Background:

• Aqueous zinc-ion batteries (ZIBs) are crucial for sustainable energy storage.
• Metallic zinc anodes in ZIBs face challenges like dendrite growth and volume changes, limiting battery lifespan.

Purpose of the Study:

• To develop a stable and reversible anode host for aqueous ZIBs.
• To investigate the role of 3D mesoporous carbon (MC) with controlled defect configurations as a zinc host.

Main Methods:

• Fabrication of 3D mesoporous carbon (MC) with tailored sp2-carbon and defect sites.
• Electrochemical testing of MC as a zinc host in asymmetric and full cells.
• Density functional theory (DFT) calculations to understand Zn adsorption on defective carbon surfaces.

Main Results:

• The MC host demonstrated dendrite-free and highly reversible zinc plating/stripping over 1000 cycles at 2 mA cm⁻².
• DFT calculations confirmed the beneficial effect of defective sp2-carbon sites on zinc adsorption.
• A full ZIB cell using a Zn@MC900 anode and V2O5 cathode achieved over 3500 cycles with excellent rate performance.

Conclusions:

• 3D mesoporous carbon with controlled defects serves as an effective host for stable zinc anodes in aqueous ZIBs.
• The study establishes a clear structure-mechanism-performance relationship for carbon hosts in ZIBs.
• This work paves the way for reliable and long-lasting aqueous ZIB applications.