Solid-State Double-Network Hydrogel Redox Electrolytes for High-Performance Flexible Supercapacitors

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Flexible supercapacitors are crucial for wearable electronics but limited by solid-state electrolytes' low energy density and poor mechanical flexibility.
• Developing advanced electrolytes is key to overcoming these limitations for practical applications.

Purpose of the Study:

• To develop novel solid-state double-network (DN) hydrogel electrolytes (HEs) with Na2MoO4 redox additives for enhanced flexible supercapacitors.
• To demonstrate the performance of symmetric supercapacitors (SSCs) utilizing these new electrolytes.

Main Methods:

• Fabrication of solid-state DN hydrogel electrolytes incorporating Na2MoO4 redox additives.
• Construction and electrochemical testing of symmetric supercapacitors (SSCs) using active carbon cloth electrodes and the developed DN HEs.

Main Results:

• The Na2MoO4-incorporated DN HEs demonstrated high electrochemical performance, excellent mechanical properties, and rapid self-recovery.
• The fabricated SSCs achieved a specific capacitance of 84 mF/cm² and an energy density of 70 μWh/cm².
• The SSCs exhibited remarkable stability, retaining 80% capacitance after 7000 charge/discharge cycles, indicating excellent flexibility.

Conclusions:

• The developed solid-state Na2MoO4 DN HEs significantly improve the performance and stability of flexible supercapacitors.
• These advanced energy-storage devices show great promise for practical applications in wearable and portable electronics.