Facile method for preparation of porous carbon derived from biomass for high performance supercapacitors

Abstract

A facile method is adopted to obtain three-dimensional porous carbonaceous material from biomass (fish seed) by pyrolysis and activation. The three-dimensional porous carbonaceous material is then fabricated as electrodes for a supercapacitor. Owing to fish seed being rich in elemental oxygen and nitrogen, the heteroatoms can introduce a pseudo-capacitance without doping. Scanning electron microscopy (SEM) analysis results show that the three-dimensional porous carbonaceous material exhibits an interconnected porous structure, which consists of micropores, mesopores and macropores. Adsorption-desorption measurements determine that its surface area is 3232 m2·g-1. Electrochemical measurements show that the biomass-derived porous carbon material displays a relatively high specific capacitance of 350 F·g-1 at 0.5 A·g-1 and an initial capacitance retention of 90.9% after 10,000 cycles in a three-electrode system, where KOH (6 M) is used as the electrolyte. In addition, the porous carbon material is also tested in a two-electrode system and exhibits a specific capacitance of 250 F·g-1 at 1 A·g-1, and the specific capacitance retention reaches 94% after 10,000 cycles at 10 A·g-1. Furthermore, the energy density of the supercapacitor is approximately 8.68 Wh·kg-1 at a power density of 125 W·kg-1 in the two-electrode system.