Nanoarchitectonics of self-supporting porous carbon electrode with heteroatoms co-doped: For high-performance supercapacitors

Abstract

Wood possesses a uniform hierarchical porous structure and high mechanical strength, rendering it an excellent precursor for the preparation of self-supporting carbon electrodes without binders and conductive agents. This paper presents an efficient method for synthesizing a self-supporting carbon electrode (HCW-0.7) with high specific surface area, hierarchical pore structure and abundant surface functional groups, utilizing simple hydrothermal pre-treatment and one-step thermochemical conversion process. The HCW-0.7 electrode demonstrates remarkable electrochemical performance, achieving an excellent specific capacitance of 298.52 F g−1 under a current density of 0.5 A g−1. The wood-based symmetrical supercapacitor (HSC) constructed with HCW-0.7 as the electrode has excellent energy density, power density and rate performance. At the power density of 287.5 W kg−1, HSC demonstrates an energy density of 9.43 Wh kg−1, exhibits its excellent electrochemical performance. Notably, even when subject to a higher power density of 5750 W kg−1, the energy density remains at 5.16 Wh kg−1. Furthermore, even after 20,000 charge and discharge cycles, HSC demonstrates a remarkable capacity retention rate of 96.24 %.