Architectural engineering of vertically expanded graphene-CoMn₂O₄ compounds based interdigital electrode for in-plane micro-supercapacitor

Structurally engineered carbon allotropes and their composites are widely applicable in various electronic/ electrochemical devices including energy storage. Herein, we develop an efficient method to fabricate graphene/ ceramic hybrid nanostructure based in-plane micro-supercapacitors (MSCs). Via CO2-laser irradiation method, MSCs patterns consisting of CoMn2O4 nanoparticles incorporated in vertically structured laser-induced graphene (CMOLIG) were formed on a freestanding graphene oxide film. The process is extremely convenient, since the laser irradiated CMOLIG patterns serve as the in-plane MSCs electrode, while the untreated graphene oxide acts as the substrate. MSCs with enhanced performance can be fabricated with the CMOLIG hybrid electrode patterns that are made of CoMn2O4 nanoparticles with pseudocapacitive properties anchored on vertically structured high-quality graphene film with excellent electrical property and high surface area. Notably, the CMOLIG electrode patterns exhibit enhanced specific capacitance with fast redox kinetics. Using the technique, customized in-plane MSCs arrays are also fabricated, which demonstrated controllable output voltage and capacitance depending on the array configuration to suit the requirements of various wearable microelectronics.