Planar patterning design and energy storage performance comparison of laser-induced graphene flexible supercapacitors.

Laser-induced graphene (LIG) has attracted considerable attention for its efficient production, controllable process, versatile precursors, and patterning capabilities. However, LIG supercapacitors (LIG SCs) devices exhibit low operating voltages and varying performance. based on patterning. Moreover, laser power significantly affects device performance. Herein, the energy storage performance of LIG SCs devices in a variety of patterns and at different laser powers is investigated. The LIG SCs device based on the interdigital pattern shows best performance compared with the spiral pattern, mirror circular pattern and concentric circular pattern LIG device. This superior performance can be attributed to the extended ion transport pathways and limited kinetic properties in interdigital pattern.  When the laser power is 2.75 W, the area-specific capacitance of the interdigital LIG SCs is up to 10.78 mF cm⁻2 at 0.2 mA cm⁻2, wide operating voltage (1.8 V) and a maximum energy density of 4.85 μWh cm⁻2. Additionally, it maintained 84.1% of its capacitance after 8,000 charge-discharge cycles and achieved an area-specific capacitance of 8.33 mF cm⁻2 when bent at an angle of 60°, suggesting outstanding cycle stability and excellent flexibility of LIG SCs. This work also provides insights for developing patterned flexible supercapacitors.