Ionic Liquid Induced Static and Dynamic Interface Double Shields for Long-Lifespan All-Temperature Zn-Ion Batteries

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Aqueous zinc-ion batteries (ZIBs) show promise but are limited by electrolyte thermal instability.
• Low-cost Zn(BF4)2 electrolytes offer potential but suffer from poor zinc anode stability.

Purpose of the Study:

• To develop a novel electrolyte for ZIBs with enhanced stability across a wide temperature range.
• To improve the cycling life and performance of zinc anodes in ZIBs.

Main Methods:

• Development of an ionic liquid based eutectic electrolyte (ILEE) using Zn(BF4)2.
• In-situ characterization and ab initio molecular dynamics simulations to study interfacial mechanisms.
• Electrochemical testing of full cells (PANI||Zn) under various temperature conditions.

Main Results:

• The ILEE exhibits remarkable stability from -100 °C to 150 °C.
• A static ZnF2 layer and a dynamic electrostatic shield were formed at the zinc anode interface, suppressing dendrite growth.
• Zinc anodes showed over 10 times improved cycling life compared to pure Zn(BF4)2 systems.
• PANI||Zn cells achieved over 9500 cycles at -40 °C and 500 cycles at 60 °C.

Conclusions:

• The developed ILEE enables stable and long-lasting ZIBs in extreme thermal environments.
• This electrolyte design offers a promising pathway for developing high-performance aqueous batteries for diverse applications.