Maximizing ion accessibility and electron transport in cationic bacterial cellulose/graphene electrode with superior capacitance and cycling stability

High-performance supercapacitors are in an Increasing demand with tremendous energy consumption and technological progress. Reduced graphene oxide (RGO) is regarded as a promising electrode material for supercapacitor due to its high surface area and excellent electrochemical properties. However, restacking and lateral aggregation are still hampering the performance of RGO. In this study, the 3-chloro-2-hydroxypropyltri methyl ammonium chloride (QA) functionalized bacterial cellulose (QBC) was introduced to prepare novel QBC-RGO composites with superior electrochemical performance. The interaction between the QA group and BC resulted in further exfoliation of RGO sheets and improved electrolyte absorption. Therefore, RGO was uniformly dispersed in QBC matrix to form a fast electron transport network with facilitated electrolyte access. The maximum specific capacitance (356 F/g) of QBC-RGO electrode at 1 A/g was obtained in 1.0 mol/L H₂SO₄ electrolyte in a three-electrode system, a value much higher than that of BC-RGO electrode (160 F/g). The energy density and power density of the QBC-RGO symmetrical supercapacitor were 31.6 Wh/kg and 400.0 W/kg, respectively. Moreover, 96.7% capacitance retention was found for QBC-RGO electrode after 10,000 cycles. The excellent performance of QBC-RGO3 electrode is derived from the continuous uniform 3D structure, good wettability, suggesting its great potential for energy storage devices. Graphical abstract: [Figure not available: see fulltext.]