Electrolyte design for reversible zinc metal chemistry

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Metal anodes are crucial for advanced energy storage but face challenges like dendrite formation and side reactions.
• Achieving high reversibility in metal plating/stripping is key for battery longevity and safety.

Purpose of the Study:

• To design a tailored electrolyte for zinc metal anodes to achieve over 99.9% Coulombic efficiency (CE).
• To address critical factors affecting anode performance: plating morphology and the anode-electrolyte interface.

Main Methods:

• Co-engineering of electrolyte salts and solvents using a dual-salt approach.
• Incorporation of organic co-solvents to stabilize the anode-electrolyte interface.
• Electrochemical testing to measure Coulombic efficiency (CE) and cycling stability.

Main Results:

• Achieved a Coulombic efficiency (CE) of 99.95% at 1 mA cm⁻² with a hybrid dual-salt electrolyte at 3.5 m concentration.
• Demonstrated stable cycling of over 1000 cycles in an anode-free cell with a ZnI₂ cathode.
• Minimal capacity loss observed in the anode-free cell under practical conditions.

Conclusions:

• The developed electrolyte design effectively addresses plating morphology and interface issues in zinc metal anodes.
• This approach provides a viable pathway for highly reversible metal anodes, advancing metal-based battery technologies.
• The findings pave the way for improved energy storage solutions using advanced battery chemistries.