Regulation of Proton Vehicle Migration for Synergetic Interfacial Stability Enables Long-Lasting Ah-Level Zinc-Ion...

Area of Science:

• Electrochemistry and Materials Science
• Energy Storage Systems

Background:

• Aqueous zinc-ion batteries (AZIBs) face limitations due to interfacial instabilities.
• Hydrogen evolution reaction (HER) and zinc dendrite growth hinder AZIB performance.
• These issues stem from proton diffusion via hydrogen bond networks.

Purpose of the Study:

• To develop a molecular-level strategy to stabilize the electrode-electrolyte interface in AZIBs.
• To suppress parasitic hydrogen evolution and control zinc deposition.
• To enhance the cycling stability and overall performance of AZIBs.

Main Methods:

• Incorporation of pyridinium trifluoroacetate (PyF), an ionic liquid additive, into the electrolyte.
• Modification of the hydrogen bond network to alter proton diffusion mechanisms.
• Characterization of the solid electrolyte interphase (SEI) formation and electrochemical performance.

Main Results:

• PyF additive reconstructs the H-bonding landscape, slowing proton mobility and promoting vehicle-type diffusion.
• Suppression of HER and promotion of dendrite-free zinc electrodeposition.
• Formation of a stable hybrid organic/inorganic SEI layer.
• Zn//Zn symmetric cells demonstrated 3900 h of cycling stability.
• A Zn//NaV₃O₈ pouch cell maintained stable operation over 50 cycles.

Conclusions:

• The PyF additive effectively enhances interfacial stability in AZIBs.
• This electrolyte engineering approach addresses key challenges in aqueous zinc metal anodes.
• The strategy offers a scalable pathway for developing high-performance, durable, and cost-effective aqueous energy storage systems.