Novel porous heteroatom-doped biomass activated carbon nanoflakes for efficient solid-state symmetric supercapacitor devices

Abstract Background Heteroatom-doped carbon structures derived from sustainable biomass for energy storage applications are a promising aspirant to the scientific community. Highly efficiency activated carbon materials derived from cheap, plentiful, but unwanted natural wastes are interestingly promising for large-scale applications. Methods Facile methods of chemical activation and carbonization using a simple pyrolysis technique under inert atmosphere were applied to synthesize heteroatom-doped porous activated carbon nanoflakes using Sechium edule leaves as biomass precursor. Significant findings The research findings of the present work indicate large effective surface area and porosity of as-synthesized nitrogen-doped activated carbon nanoflakes that led to display excellent specific capacitance of 334 F g−1 at 1 A g−1 current density in strong acidic electrolyte using a three-electrode system. The electrokinetic analysis demonstrate that the major contribution of capacitive nature (90%) was observed to accumulate the total charge. Further, all solid-state symmetric supercapacitor (SSC) devices fabricated using as-synthesized carbon nanoflakes with gel electrolyte (PVA-H2SO4) exhibited a maximum capacitance of 114 F g−1 at 1 A g−1, a maximum energy density of 63.33 Wh kg−1 and power density of 10 kW kg−1. The retention of specific capacitance was found to be 93% with 5000 continuous cycles of charge-discharge process.