A Gradient Solid-like Electrolyte Stabilizing Zn Anodes by In Situ Formation of a ZnSe Interphase

Area of Science:

• Electrochemistry
• Materials Science
• Energy Storage

Background:

• Rechargeable aqueous zinc-ion batteries offer safety and cost benefits but suffer from slow electrode kinetics and zinc dendrite issues.
• These limitations hinder their widespread practical application in energy storage devices.

Purpose of the Study:

• To develop a gradient solid-like electrolyte (GSLE) for improving zinc anode performance.
• To address challenges in kinetics and dendrite formation in aqueous zinc-ion batteries.

Main Methods:

• Fabrication and characterization of a gradient solid-like electrolyte (GSLE).
• Evaluation of GSLE conductivity and Zn2+ transference number.
• Testing of symmetric zinc cells and vanadium-based full cells with GSLE.

Main Results:

• GSLE exhibits high conductivity (13.3 mS cm-1) and Zn2+ transference number (0.67).
• GSLE promotes Zn2+-rich interface, accelerates kinetics, and forms a protective ZnSe interphase.
• Symmetric cells show stable cycling (>1400 h) and high critical current tolerance (15 mA cm-2).
• Full cells achieve 125.4 mAh g-1 capacity and 90% retention after 1000 cycles.

Conclusions:

• The developed GSLE effectively enhances the performance of aqueous zinc-ion batteries.
• GSLE mitigates dendrite growth and improves interfacial stability, paving the way for practical applications.