High-energy-density, all-solid-state microsupercapacitors with three-dimensional interdigital electrodes of...

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• All-solid-state microsupercapacitors (MSCs) are crucial for high-energy-density storage.
• Traditional MSCs often face limitations in ion accessibility and diffusion pathways.

Purpose of the Study:

• To fabricate and evaluate novel all-solid-state MSCs with three-dimensional (3D) electrodes.
• To investigate the performance of graphene/polymer electrolyte (PE) and activated carbon (AC)/PE composite electrodes.

Main Methods:

• Fabrication of 3D MSCs utilizing graphene or AC as active materials and PE as the electrolyte.
• Electrochemical testing, including capacitance measurements at a scan rate of 5 mV s(-1).
• Long-term cycling stability tests over 10,000 charge/discharge cycles.

Main Results:

• Graphene/PE and AC/PE composite electrodes achieved high areal capacitances of 95 and 134 mF cm(-2), respectively.
• Graphene/PE MSCs exhibited a ~70% specific capacitance increase after 10,000 cycles due to electro-activation.
• AC/PE MSCs demonstrated excellent cycling stability.

Conclusions:

• The developed 3D MSCs with PE offer competitive performance compared to liquid electrolyte counterparts.
• These solid-state MSCs show significant potential for high-density energy storage applications.
• The electro-activation mechanism in graphene/PE MSCs enhances long-term performance.