Ultra-Stretchable Anti-Freezing Hydrogel Electrolytes Cross-Linked by Liquid Metal Particle Initiators Toward Soft...

Area of Science:

• Materials Science
• Electrochemistry
• Polymer Science

Background:

• Hydrogels offer mechanical flexibility and ionic conductivity for soft energy storage devices.
• High water content limits hydrogel mechanical strength and causes freezing at sub-zero temperatures.

Purpose of the Study:

• To develop anti-freezing hydrogels with enhanced mechanical strength and stability at low temperatures.
• To investigate the potential of these hydrogels as electrolytes in soft energy storage devices.

Main Methods:

• Utilized liquid metal (LM)-initiated free-radical polymerization.
• Incorporated stearyl methacrylate (SMA) to create hydrophobic associations and increase physical cross-linking.
• Fabricated supercapacitors using the developed hydrogel electrolyte and activated carbon electrodes.

Main Results:

• Achieved hydrogels with high mechanical properties (907% elongation at break, 766 kPa tensile strength).
• Demonstrated excellent low-temperature performance: maintained ionic conductivity (3.39 S m⁻¹ at -20 °C) and stretchability (897% elongation at break).
• Supercapacitors exhibited high areal capacitance (93.52 mF cm⁻²) and excellent cycle stability (98% capacitance retention after 45,000 cycles).

Conclusions:

• The developed hydrogels overcome limitations of traditional hydrogels, offering robust mechanical strength and anti-freezing properties.
• The novel hydrogel electrolyte enables high-performance, durable soft energy storage devices suitable for demanding conditions.