A Hydrogel Electrolyte-Based Zn-CO₂ Battery with Improved Life.

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Aqueous Zn-CO2 batteries offer a sustainable path towards carbon neutrality and energy storage.
• Challenges include anode corrosion from water and electrolyte leakage, hindering practical application.

Purpose of the Study:

• To develop a robust hydrogel electrolyte for aqueous Zn-CO2 batteries to overcome limitations of liquid electrolytes.
• To enhance anode stability, ion transport, and overall battery performance.

Main Methods:

• Fabrication of a polyvinyl alcohol (PVA)-based hydrogel electrolyte incorporating an ionic liquid plasticizer.
• Characterization of the hydrogel's ionic conductivity, mechanical strength, flexibility, and self-healing properties.
• Testing of symmetric Zn metal batteries and Zn-CO2 batteries with Ru nanoparticle cathodes using the developed hydrogel electrolyte.

Main Results:

• The PVA hydrogel electrolyte demonstrated high ionic conductivity (7.95 × 10-3 S cm-1) and excellent mechanical properties.
• Significant inhibition of anode corrosion and promotion of uniform Zn deposition were observed.
• Symmetric Zn batteries showed stable cycling for over 2000 hours.
• The Zn-CO2 battery achieved a high discharge capacity of 6028 mAh g-1 and 90 cycles.

Conclusions:

• The developed PVA hydrogel electrolyte effectively addresses anode corrosion and stability issues in aqueous Zn-CO2 batteries.
• This hydrogel enables efficient energy storage and reversible cycling, paving the way for practical carbon-neutral battery technologies.