Preparation and Characterization of Physically Activated Carbon and Its Energetic Application for All-Solid-State Supercapacitors: A Case Study

Biomass-derived activated carbons have gained significantattentionas electrode materials for supercapacitors (SCs) due to their renewability,low-cost, and ready availability. In this work, we have derived physicallyactivated carbon from date seed biomass as symmetric electrodes andPVA/KOH has been used as a gel polymer electrolyte for all-solid-stateSCs. Initially, the date seed biomass was carbonized at 600 degrees C(C-600) and then it was used to obtain physically activated carbonthrough CO2 activation at 850 degrees C (C-850). The SEMand TEM images of C-850 displayed its porous, flaky, and multilayertype morphologies. The fabricated electrodes from C-850 with PVA/KOHelectrolytes showed the best electrochemical performances in SCs (Luet al. Energy Environ. Sci., 2014, 7, 2160) application. Cyclic voltammetry was performed from5 to 100 mV s(-1), illustrating an electric doublelayer behavior. The C-850 electrode delivered a specific capacitanceof 138.12 F g(-1) at 5 mV s(-1), whereasit retained 16 F g(-1) capacitance at 100 mV s(-1). Our assembled all-solid-state SCs exhibit an energydensity of 9.6 Wh kg(-1) with a power density of 87.86W kg(-1). The internal and charge transfer resistancesof the assembled SCs were 0.54 and 17.86 omega, respectively. Theseinnovative findings provide a universal and KOH-free activation processfor the synthesis of physically activated carbon for all solid-stateSCs applications.