Surface Segregation Reconstructing Alloy Substrate for Ultra-Stable Zinc-Based Batteries.

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Aqueous zinc-based batteries (AZBs) offer safe, cost-effective, and eco-friendly energy storage.
• Challenges include uncontrolled dendrite growth, low zinc utilization, and reduced energy density, hindering practical use.
• Existing inert current collectors have limitations like rolling defects and localized zinc deposition.

Purpose of the Study:

• To develop a new strategy for uniform zinc deposition in AZBs.
• To improve the cycling stability and energy density of AZBs.
• To overcome limitations of current collectors for practical AZB applications.

Main Methods:

• A segregation strategy using copper-tin (Cu-Sn) alloy substrates.
• A 1-minute heating process to induce directional tin atom migration and surface reconstruction.
• Characterization of the reconstructed surface and evaluation of zinc deposition behavior.

Main Results:

• Formation of a reconstructed surface with exposed Cu (111) facets, uniform voids, and CuO particles.
• Synergistic optimization reducing nucleation barriers and enabling dense zinc deposition.
• Exceptional cycling stability demonstrated in asymmetric cells (≈10,000 cycles, 99.8% Coulombic efficiency), Zn-I2 coin cells (40,000 cycles), and pouch cells (5000 h, 91% retention).

Conclusions:

• The Cu-Sn alloy substrate with a reconstructed surface effectively promotes uniform zinc deposition.
• This approach significantly enhances the stability and longevity of AZBs.
• The strategy offers a scalable, cost-effective pathway for the commercialization of AZBs.