Graphene Nanoribbons Enhancing the Electronic Conductivity and Ionic Diffusion of Graphene Electrodes for High-Performance Microsupercapacitors

The electrochemical performance of microsupercapacitors with graphene electrodes is reduced by the issue of graphene sheets aggregation, which limits electrolyte ions penetration into electrode. Increasing the space between graphene sheets in electrodes facilitates the electrolyte ions penetration, but sacrifices its electronic conductivity which also influences the charge storage ability. The challenging task is to improve the electrodes' electronic conductivity and ionic diffusion simultaneously, boosting the device's electrochemical performance. Herein, we experimentally realize the enhancement of both electronic conductivity and ionic diffusion from 2D graphene nanoribbons assisted graphene electrode with porous layer-upon-layer structure, which is tailored by graphene nanoribbons and self-sacrificial templates ethyl cellulose. The designed electrode-based device delivers a high areal capacitance of 71 mF cm-2 and areal energy density of 9.83 mu Wh cm-2, promising rate performance, outstanding cycling stability with 97% capacitance retention after 20 000 cycles, and good mechanical properties. The strategy paves the way for fabricating high-performance graphene-based MSCs. The graphene and graphene nanoribbons electrodes with porous layer structure are designed and 3D printed. The electrodes possess both improved ionic and electronic properties thanks to the assistance of 2D graphene nanoribbons and self-sacrificial templates of ethyl cellulose. The microsupercapacitors based on the newly designed electrodes deliver high energy density of 9.83 mu Wh cm-2.image