A Holistic Additive Protocol Steers Dendrite-Free Zn(101) Orientational Electrodeposition

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Zinc anode stability is crucial for commercializing high-energy-density batteries.
• Current methods for orientational deposition face challenges in balancing ion reduction and mass transfer.

Purpose of the Study:

• To develop an electrolyte additive protocol for enhanced zinc anode stability.
• To investigate the role of bio-derived dextrin in modulating zinc electrodeposition.

Main Methods:

• Incorporation of dextrin molecules into zinc sulfate electrolyte.
• Electrochemical performance testing (symmetric cells, Zn@Cu electrodes).
• Molecular dynamics simulations to analyze ion behavior and deposition mechanisms.

Main Results:

• Dextrin addition alleviates concentration polarization by accelerating Zn²⁺ diffusion and retarding reduction.
• Achieved predominant (101) and (101)/(002) zinc textures on various current collectors and Zn foils.
• Symmetric cells demonstrated over 4000 hours of cycling life at 0.5 mA cm^-2 /0.5 mAh cm^-2.
• Zn@Cu electrodes sustained 240 hours at 40% depth of discharge.

Conclusions:

• Dextrin is an effective electrolyte additive for promoting stable and uniform zinc electrodeposition.
• The protocol enhances electrical field distribution and zinc anode longevity.
• This approach offers a promising strategy for developing practical zinc-based batteries.