Multidimensional Co-Exfoliated Activated Graphene-Based Carbon Hybrid for Supercapacitor Electrode

Herein, a simple route for the fabrication of highly porous-activated few-layer graphene for application in supercapacitors as an electrode material is reported. The process makes use of natural and renewable materials, which is an essential prerequisite, especially for large-scale application. Few-layer graphene is exfoliated in aqueous suspension with the aid of microfibrillated cellulose (MFC), an environmentally benign eco-friendly medium that is low-cost, biodegradable, and sustainable. The exfoliated product is subsequently activated to increase the surface area and to form the desired pore structure. The prepared electrode materials exhibit a high surface area of up to 720 m² g⁻¹. MFC is also used as a nontoxic environmentally friendly binder in the electrode application. The electrochemical performance is evaluated in a three-electrode system, and the prepared samples show a high specific capacitance of up to 120 F g⁻¹ at a current density of 1 A g⁻¹. The samples also exhibit a high capacity-retention rate of about 99% after 5000 cycles and 97% after 10 000 cycles. The proposed method for the fabrication of graphene-based supercapacitor electrode materials, based largely on renewable and sustainable materials, offers potential for commercially viable applications.