Tailoring the surface morphology and nanoparticle distribution of laser-induced graphene/Co3O4 for high-performance flexible microsupercapacitors

Recent trends have witnessed laser induced graphene (LIG) syntheses on various materials from synthetic polymers to natural precursors. Herein, porcine skin derived gelatin was used as a medium to modify the surface morphology and nanoparticle distribution of in situ synthesized Co3O4 /LIG on polyimide (PI) film. By varying the applied laser fluence, the surface morphology of LIG transitions from a 3D porous structure to a multilayered structure, Co3O4 progressively distributes from the surface to the inside of the LIG structure, and the structure changes from a sphere to a whisker-like shape. These altered attributes contribute to distinct differences in the double layer capacitance and pseudocapacitance behaviors of Co3O4 /LIG, as reflected in its associated electrochemical performance. Additionally, a facile fabrication strategy including simple casting and peeling steps was used to generate stretchable microsupercapacitors (MSCs) on a waterborne polyurethane (WPU) substrate. The as-prepared stretchable MSCs present outstanding areal capacitance and excellent mechanical flexibility, whereas their electrochemical differences are significantly minimized and dominated by their inner structures.