Bicontinuous Zinc Monoliths with a Protective Coating for Practical Zinc-Powder Anodes

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Zinc powder (ZnP) is a promising anode for aqueous zinc-ion batteries (AZIBs) due to its processability and capacity control.
• ZnP anodes face challenges like electrolyte corrosion, unstable electrical contacts, and strain-induced isolation, hindering their practical application.

Purpose of the Study:

• To engineer a robust ZnP anode that overcomes common failure mechanisms in AZIBs.
• To enhance the electrochemical performance and long-term stability of ZnP anodes for practical energy storage.

Main Methods:

• Fabrication of a bicontinuous monolithic ZnP anode with continuous metallurgical bonding.
• Application of a protective metallic bismuth coating to the ZnP anode surface.
• Testing of symmetric cells and full cells with a NaV3O8.1.5H2O cathode.

Main Results:

• The monolithic structure and pore channels accommodated volumetric strain and homogenized ion flux.
• The bismuth coating suppressed parasitic reactions and promoted desirable Zn (002) deposition.
• Symmetric cells demonstrated exceptional stability (4680 h at 1 mA cm⁻²/1 mAh cm⁻²).
• Full cells achieved 4.2 mAh cm⁻² initial capacity and maintained 2.5 mAh cm⁻² after 1200 cycles.

Conclusions:

• The developed monolithic ZnP anode with a bismuth coating effectively addresses electrochemical failure issues in AZIBs.
• This approach offers a viable strategy for enhancing the practical implementation of AZIBs.
• The study provides critical insights into designing stable and high-performance zinc anodes for next-generation batteries.