Hierarchically Assembled Mn2O3/Porous Graphene Electrodes Synthesized via High Speed and Continuous Laser-Scribing Strategy for High-Performance Microsupercapacitors

Abstract

Micro-supercapacitors (mSCs) have emerged as next-generation energy storage components suitable for portable, flexible, and eco-friendly electronic device system. In particular, electric double-layer (EDL) mSCs utilizing flexible graphene electrodes have gained significant attention due to their quick and efficient charge/discharge capabilities. Despite significant progress in fabricating mSCs, particularly through the development of laser-induced graphene (LIG) for creating 3D porous electrodes, challenges remain in increasing both energy and power densities. One promising strategy to address these challenges is the incorporation of pseudo-capacitive materials into the 3D graphene structure. However, conventional methods for embedding pseudo-capacitive materials often involve complex and additional labor-intensive steps to the manufacturing process. In this work, we introduce a high-speed mSC fabrication method (< 5 min) that employs a continuous laser-scribing process to directly integrate Mn₂O₃, a pseudo-capacitive material, onto LIG electrodes, forming hierarchical Mn₂O₃/LIG structure. By precisely controlling the fabrication parameter, this approach can significantly improve the electrochemical performance by optimizing the density and thickness of Mn₂O₃, leading to 550.5% increase in capacitance and energy density compared to the LIG electrode. Additionally, the mSCs exhibit outstanding cyclic (> 88% @ 20,000 cycles) and mechanical stability (@ bending radius of 5 mm), confirming their potential for seamless integration into electronic circuits. This innovation not only simplifies the production process of high-performance mSCs but also broadens their potential applications in sustainable and compact electronic device system.