Highly conductive, conformable ionic laser-induced graphene electrodes for flexible iontronic devices

Area of Science:

• Materials Science
• Nanotechnology
• Electrochemistry

Background:

• Iontronic devices utilize ion gels and electrodes, forming an electrical double layer (EDL) crucial for performance.
• Stable interfacial formation between ion gels and electrodes remains a key challenge in soft electronics.
• Existing research on ion gels and electrode materials has not fully overcome interfacial stability issues.

Purpose of the Study:

• To develop a method for fabricating stable and highly conductive electrodes for iontronic devices.
• To improve electrical double layer (EDL) formation at the ion gel-electrode interface.
• To enhance the performance of iontronic devices, specifically vertical capacitors.

Main Methods:

• Utilized CO2 irradiation for direct fabrication of laser-induced graphene (LIG) electrodes on polyimide (PI)-based ion gels.
• Developed ionic laser-induced graphene (i-LIG) electrodes using the PI ion gel as a precursor.
• Investigated ion migration, thermal transfer effects, and intercalation phenomena within the ion gel and graphene structure.

Main Results:

• Achieved highly conductive, conformable LIG electrodes directly on PI ion gel.
• PI ion gel demonstrated exceptional EDL formation due to efficient ion migration.
• i-LIG electrodes exhibited enhanced crystallinity and an expanded upward porous structure.
• Fabricated vertical capacitors using i-LIG and PI ion gels showed reduced interfacial resistance and increased EDL capacitance.

Conclusions:

• CO2 irradiation offers a bottom-up approach for advanced iontronic device fabrication.
• The developed i-LIG electrodes and PI ion gels significantly improve interfacial properties.
• This work presents a new perspective for advancing next-generation iontronic devices with enhanced performance.