Peat soil-derived silica doped porous graphitic carbon with high yield for high-performance all-solid-state symmetric supercapacitors

The cost-effective fabrication of lightweight, safe, and solid-state supercapacitors with excellent performance, such as high energy and power densities and long cycle life, has recently become a critical issue in next-generation energy storage systems. As a result, current research efforts are focused on developing high-performance advanced electrode materials with high capacitance and outstanding stability, and solid electrolytes that provide flexibility and safety. Herein, the Marsh clay (peat soil) derived silica doped high yield and porous graphitic carbon (MCC) produced by simple pyrolysis and PVA/KOH polymer gel electrolyte are used as innovative components of the all-solid-state symmetric supercapacitor. Various characterizations were used to study the phase, microstructural, thermal, morphological, porosity, surface area, and compositional examination of the materials. An all-solid-state symmetric supercapacitor device based on the MCC and PVA/KOH gel electrolyte is fabricated. The developed supercapacitor device delivers a maximum specific capacitance of 160 F/g (at a scan rate of 10 mV/s) and exhibits a high energy density of ~18 Wh/kg at a power density of ~312 W/kg, and displays low resistance and good cycling stability. Overall, the developed all-solid-state symmetric supercapacitor with the novel MCC and PVA/KOH gel electrolyte represents the potential for high-performance supercapacitors.