Hydrogen Atom Capture Toward Dense Solid Electrolyte Interface for Long-Cycling Aqueous Zinc-Ion Batteries

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Aqueous zinc-ion batteries (AZIBs) offer high safety but face challenges with zinc dendrite growth and hydrogen evolution reaction (HER).
• The solid-electrolyte interface (SEI) is crucial for AZIB performance, yet its in situ construction is hindered by the loose structure caused by HER.

Purpose of the Study:

• To develop a universal strategy for in situ constructing a dense and uniform inorganic SEI in AZIBs.
• To address the limitations of HER and zinc dendrite growth for improved AZIB stability.

Main Methods:

• Introduction of potassium persulfate (PSS) as a hydrogen atom scavenger.
• In situ formation of a zinc hydroxide sulfates (ZHS) SEI layer.
• Electrochemical testing of Zn//Zn symmetric cells and Zn||NVO full cells.

Main Results:

• PSS effectively scavenges hydrogen atoms, inhibiting HER and preventing loose SEI formation.
• PSS participates in forming a dense, uniform ZHS-SEI, which is electronically insulating and suppresses dendrite growth.
• Zn//Zn symmetric cells demonstrated prolonged stability (1882 h at 5 mA cm⁻²), and Zn||NVO full cells showed improved cycling performance.

Conclusions:

• The proposed hydrogen atom scavenging strategy with PSS enables the in situ construction of a robust ZHS-SEI.
• This approach significantly enhances the cycling stability and safety of AZIBs by mitigating HER and dendrite issues.
• The study offers a novel perspective for stabilizing zinc anodes in aqueous energy storage systems.