Highly Porous Willow Wood-Derived Activated Carbon\nfor High-Performance Supercapacitor Electrodes

Abstract

In this study, we present willow\nwood as a new low-cost, renewable,\nand sustainable biomass source for the production of a highly porous\nactivated carbon for application in energy storage devices. The obtained\nactivated carbon showed favorable features required for excellent\nelectrochemical performance such as high surface area (∼2 800\nm² g^–1) and pore volume (1.45 cm³ g^–1), with coexistence of micropores and\nmesopores. This carbon material was tested as an electrode for supercapacitor\napplication and showed a high specific capacitance of 394 F g^–1 at a current density of 1 A g^–1 and good cycling stability, retaining ∼94% capacitance after\n5 000 cycles (at a current density of 5 A g^–1) in 6 M KOH electrolyte. The prepared carbon material also showed\nan excellent rate performance in a symmetrical two-electrode full\ncell configuration using 1 M Na₂SO₄ electrolyte,\nin a high working voltage of 1.8 V. The maximum energy density and\npower density of the fabricated symmetric cell reach 23 W h kg^–1 and 10 000 W kg^–1, respectively.\nThese results demonstrate that willow wood can serve as a low-cost\ncarbon feedstock for production of high-performance electrode material\nfor supercapacitors.