All-Soft Supercapacitors Based on Liquid Metal Electrodes with Integrated Functionalized Carbon Nanotubes

Area of Science:

• Materials Science
• Electrochemistry
• Soft Robotics

Background:

• Soft energy storage is crucial for integrated soft microsystems.
• Conventional supercapacitors use brittle materials prone to mechanical failure.
• Need for soft, stretchable, and conductive electrodes without performance loss.

Purpose of the Study:

• To present all-soft supercapacitors for integrated soft microsystems.
• To utilize liquid metal electrodes with functionalized carbon nanotubes (CNTs).
• To ensure electrode adhesion and prevent delamination under mechanical deformation.

Main Methods:

• Fabrication of all-soft supercapacitors using eutectic gallium-indium (EGaIn) liquid metal electrodes.
• Integration of functionalized CNTs with oxygen functional groups for enhanced adhesion to EGaIn.
• Electrochemical performance testing under varying mechanical strain.

Main Results:

• Achieved areal capacitances up to 12.4 mF cm⁻².
• Demonstrated stable performance with nearly unchanged capacitance under 30% strain.
• Maintained over 95% capacitance after >4200 cycles with periodic 30% strain.

Conclusions:

• Successfully developed delamination-free, soft, and stretchable electrodes.
• Demonstrated the potential for integrated soft microsystems by powering an LED.
• Established a viable approach for robust soft energy storage devices.