Enhanced supercapacitor performance of hierarchical mesoporous sulfur-doped carbon particles from biomass waste for energy storage

In this study, sulfur doping was carried out on activated carbon derived from biomass waste chestnut shells using a simple process involving activation with sulfuric acid to enhance the specific capacitance of supercapacitors (AC/CS). With the carbon surface becoming more polarized by the sulfonation process, it is aimed to achieve high wettability, which is important for supercapacitors, and to effectively transfer the electrolyte to the pores carbon materials. The resulting activated carbon particles were characterized by EDS, FTIR, SEM, Raman, XPS, nitrogen adsorption and XRD analyses. EIS, CV and GCD analyses were used for electrochemical measurements. At a current density of 2 A/g, there is an approximately 1.68-fold increase in the capacitance value for sulfonated AC/CS@GCE compared to the AC/CS@GCE electrode. The sulfonated AC/CS@GCE electrode showed ideal cycling stability with a capacitance retention rate of similar to 84.7% after 10000 cycles. The Rct values of CS@GCE and sulfonated AC/CS@GCE electrodes were-15.2 Omega and-113 Omega, respectively. The AC/CS@GCE//AC/CS@GCE device can store 4.98 Wh/kg of electrochemical energy with a power density of 161.5 W/kg current density of 2 A/g. At a higher current density of 10 A/g, it can store 2.22 Wh/kg of electrochemical energy with a power density of 799.2 W/kg.