Oriented Zn plating guided by aligned ZnO hexagonal columns realizing dendrite-free Zn metal electrodes

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Aqueous zinc-ion batteries (AZIBs) are attractive due to their low cost and high safety.
• Dendritic growth, side reactions, and corrosion limit the Zn stripping/plating reversibility and applicability of AZIBs.
• Existing zincophilic protective layers are often thick, lack defined crystalline orientation, and require binders.

Purpose of the Study:

• To develop a facile, scalable, and cost-effective method to create oriented protective layers for AZIBs.
• To investigate the effect of vertically aligned ZnO hexagonal columns on Zn metal electrode performance.
• To enhance the Zn stripping/plating reversibility and overall battery performance.

Main Methods:

• Solution-based growth of vertically aligned ZnO hexagonal columns with (002) top surface on Zn foil.
• Characterization of the ZnO protective layer's morphology, orientation, and thickness (1.3 µm).
• Electrochemical evaluation of the modified Zn electrode in Zn//Zn, Zn//Ti, and Zn//MnO2 cells.

Main Results:

• The oriented ZnO layer promotes homogenous and nearly horizontal Zn plating due to low lattice mismatch with Zn.
• The modified Zn electrode exhibits dendrite-free behavior, suppressed corrosion, and reduced byproduct formation.
• Significantly improved Zn stripping/plating reversibility was observed in various cell configurations.

Conclusions:

• Vertically aligned ZnO columns serve as an effective oriented protective layer for Zn metal anodes.
• This approach enhances Zn plating reversibility and suppresses detrimental side reactions in AZIBs.
• The findings offer a promising strategy for guiding metal plating processes in energy storage devices.