Stabilizing Zinc Anodes Through Trace Additive Mediated Solvation and Hydrogen-Bond Network

Area of Science:

• Electrochemistry
• Materials Science

Background:

• Aqueous zinc-ion batteries (AZIBs) offer safe, low-cost large-scale energy storage.
• Key challenges include hydrogen evolution reaction (HER) and dendritic zinc growth, linked to interfacial water structure.

Purpose of the Study:

• To investigate the use of DL-2,3-dimercapto-1-propanesulfonic acid sodium salt (DMPS) as an electrolyte additive in AZIBs.
• To understand how DMPS modulates the interfacial water structure to improve zinc anode stability.

Main Methods:

• Introduction of trace amounts of DMPS as an electrolyte additive.
• Analysis of DMPS anion (DMPS-) adsorption on the zinc surface.
• Investigation of DMPS- interaction with Zn2+ solvation sheath and interfacial water.
• Electrochemical testing of Zn||Zn symmetric cells and Zn||MnO2 full cells.

Main Results:

• DMPS- effectively suppresses HER by disrupting the interfacial hydrogen-bond network and lowering water activity.
• DMPS- promotes uniform zinc deposition with a preferred (101) orientation through selective adsorption.
• Zn||Zn symmetric cells achieved over 2000 hours of cycling stability.
• Zn||MnO2 full cells demonstrated enhanced rate capability and prolonged cycling life.

Conclusions:

• Rational modulation of interfacial water via trace electrolyte additives is a viable strategy for stabilizing zinc metal anodes.
• DMPS acts as a multifunctional additive, simultaneously addressing HER and dendritic growth in AZIBs.
• This approach significantly enhances the performance and durability of aqueous zinc-ion batteries.