Hydrogen-Free and Dendrite-Free All-Solid-State Zn-Ion Batteries

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Zinc-ion batteries face challenges with hydrogen evolution reaction (HER) and dendrite growth, limiting their lifespan and safety.
• Oxygen-induced corrosion and passivation further degrade battery performance.

Purpose of the Study:

• To develop an ionic-liquid-based Zn salt electrolyte to overcome HER and dendrite issues in zinc-ion batteries.
• To demonstrate the long-term stability and performance of this new electrolyte in both conventional and all-solid-state configurations.

Main Methods:

• Formulation of an ionic-liquid-based Zn salt electrolyte.
• Fabrication of a solid polymer electrolyte using poly(vinylidene fluoride-hexafluoropropylene) and poly(ethylene oxide)/ionic-liquid-based Zn salt.
• Electrochemical testing of Zn plating/stripping and full cell cycling performance.

Main Results:

• Achieved hydrogen-free, dendrite-free Zn plating/stripping for over 1500 hours (3000 cycles) with ~100% coulombic efficiency.
• Demonstrated extended cycle life (>40,000 cycles) at 4 A g⁻¹ and 2.05 V with a cobalt hexacyanoferrate cathode.
• Developed an all-solid-state Zn-ion battery with excellent cycling stability (30,000 cycles at 2 A g⁻¹) across a wide temperature range (-20 °C to 70 °C) and mechanical abuse tolerance.

Conclusions:

• The novel ionic-liquid electrolyte effectively suppresses HER and dendrite formation, significantly enhancing Zn-ion battery longevity.
• The developed all-solid-state Zn-ion battery showcases remarkable stability, safety, and performance, marking a significant advancement in the field.