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.