Regulating Interface Engineering by Helmholtz Plane Reconstructed Achieves Highly Reversible Zinc Metal Anodes

Area of Science:

• Electrochemistry
• Materials Science

Background:

• Aqueous zinc metal batteries face stability issues due to zinc dendrite growth and parasitic reactions.
• These issues significantly hinder the practical application of zinc metal batteries.

Purpose of the Study:

• To develop a synergistic strategy to stabilize zinc anodes in aqueous electrolytes.
• To precisely regulate the interface chemistry between the zinc anode and the electrolyte by reconstructing the Helmholtz plane.

Main Methods:

• Investigated the effect of pyridine oxide (PNO) as an additive in the electrolyte.
• Utilized experimental investigations and theoretical calculations to analyze interface modifications.
• Examined changes in the coordination environment, solvation sheath, and adsorption behavior at the anode-electrolyte interface.

Main Results:

• Pyridine oxide (PNO) additive altered the solvation sheath in the Outer Helmholtz Plane (OHP) and displaced water from the Inner Helmholtz Plane (IHP).
• Achieved compact and dense zinc deposition along the Zn (002) plane, suppressing parasitic reactions.
• Demonstrated stable cycling performance in symmetric cells (>2300 h at 1 mA cm⁻²) and high depth of discharge stability (>400 h at 85% DoD).
• Zn||AQ cells retained 80% capacity after 3000 cycles with high mass loading (22 mg cm⁻²).

Conclusions:

• The synergistic regulation of the Helmholtz plane by PNO effectively stabilizes zinc anodes.
• PNO additive significantly enhances the cycling stability and performance of aqueous zinc metal batteries.
• This strategy offers a promising approach for developing practical and high-performance zinc metal batteries.