A Bilayer Electrode Architecture Enabling SnO₂-Induced Spatial-Controllable Zinc Deposition for...

Area of Science:

• Electrochemistry
• Materials Science
• Energy Storage

Background:

• Aqueous zinc-based flow batteries (ZFBs) are promising for grid-scale energy storage.
• Limited areal capacity due to uncontrolled zinc deposition and low electrode volume utilization hinders ZFB deployment.

Purpose of the Study:

• To develop a spatially controllable deposition strategy for ZFBs.
• To enhance areal and volumetric capacity through a novel electrode architecture.

Main Methods:

• Designed a bilayer electrode architecture with SnO2-functionalized carbon felt (bottom) and pristine carbon felt (top).
• Investigated the effect of the bilayer structure on zinc deposition behavior and electrochemical performance.

Main Results:

• Achieved an ultrahigh areal capacity of 330 mAh cm⁻² and volumetric capacity of 1100 mAh cm⁻³.
• Demonstrated a 65% improvement over conventional electrodes.
• Exhibited exceptional durability over 175 cycles under harsh conditions (100% state/depth of charge).

Conclusions:

• The bilayer electrode architecture effectively controls spatial zinc deposition, reversing it from surface-clogging to internal-to-external filling.
• This approach significantly improves electrode volume utilization and battery performance.
• Provides a robust strategy for developing high-areal-capacity ZFBs for practical applications.