Multifunctional role of reduced graphene oxide binder for high performance supercapacitor with commercial-level mass loading

Effective specific-surface-area (SSA) utilization of active materials and rapid ion/electron transport within electrodes with commercial-level mass loadings (>10 mg cm−2) are critical for the practical applications of supercapacitors (SCs). Herein, we demonstrate such SCs based on porous activated carbons (PACs) derived from the inexpensive and abundant biomass and reduced graphene oxide (rGO) as a multifunctional conductive binder. The rGO binder incorporated into PAC-based electrodes markedly boosts the capacitive performance of SCs by forming a three-dimensional interconnected network that leads to fast ion diffusion with easy accessibility as well as larger accessible surface areas of active materials across the entire electrode. The resultant electrodes (12 mg cm−2) exhibit outstanding specific capacitance (324 F g−1 at 0.1 A g−1) and areal capacitance (3.9 F cm−2 at 1.2 mA cm−2), along with excellent cycling stability (capacitance retention of ~98% after 10,000 cycles). This strategy provides a versatile avenue for designing scalable and high-performance SCs based on a rich family of porous carbons and their hybrid composites in a sustainable fashion. [Display omitted] •The role of the rGO binder in supercapacitors with high mass loadings was studied.•The rGO conductive network preserve a high SSA of PACs across the entire electrode.•The PAC-rGO electrodes show a high specific capacitance with high mass loadings.•The PAC-rGO12 exhibits remarkable rate capability and cycling stability.