Porous carbon derived from Ailanthus altissima with unique honeycomb-like microstructure for high-performance supercapacitors

Abstract

Biomass-derived porous activated carbon (AC) with high surface area of up to 1776.9 m² g⁻¹ was prepared by KOH and urea activation of Ailanthus altissima stems with unique honeycomb-like microstructure at 800 °C. As an electrode material for supercapacitors, the AC samples exhibited a remarkably large capacitance of 300.6 F g⁻¹ at 0.5 A g⁻¹ in 1 M H₂SO₄ and retained up to 213.4 F g⁻¹ even at a current density of 20 A g⁻¹. It is worth noting that no obvious capacitance loss was observed over 5000 charge/discharge cycles, clearly demonstrating the robust long-term stability. The excellent performance of the special carbon electrode can be attributed to the inherent honeycomb-like porous microstructure of Ailanthus altissima stems, which can offer more surfaces for activation by KOH to generate a more microporous network. This work provides a promising strategy to take full advantage of the unique microstructure of raw materials from nature via simple technologies to achieve sustainable energy development.