Wood-derived carbon electrode for all-solid-state supercapacitor with ultrahigh volumetric and area capacitances

Abstract

With the development of emerging electronic devices, there is a growing requirement for advanced energy storage systems. Herein, a cost-effective, facile, and sustainable process is developed through to produce an all-solid-state supercapacitor (ASC) from lignocellulosic biomass with wood-derived carbon electrode. The micro/nanostructures of the carbon electrode can be facile altered via biomass pretreatment and hot-pressing process. Ultrahigh volumetric and areal capacitances of 31.4 F cm⁻³ (5 mA cm⁻³) and 12.5 F cm⁻² (5 mA cm⁻²) were achieved, respectively. It also exhibits an outstanding capacitance of 19.7 F cm⁻³ (20 mA cm⁻³) and 8.6 F cm⁻² (20 mA cm⁻²). Significantly, the ASC assembled from the carbon electrode has high capacitance of 16.2 F cm⁻³ and high energy density of 1.82 mWh cm⁻³, and maintains a capacitance retention of over 90 % after 5000 charging/discharging cycles. These performances allow to open up new opportunities to produce sustainable wood-derived electrodes for the applications in energy storage.