Improving the capacitive performance of wood-derived carbon monolith by anchoring heteroatom-doped carbon nanotubes in the vessels via in situ chemical vapor deposition

Wood, with high carbon contents and abundant vertically oriented channels, has unique advantages in preparing high mass-loading carbon-based freestanding supercapacitor electrodes. However, there is considerable room for enhancing the capacitive performance of wood-derived carbon electrodes. A one-step chemical vapor deposition (CVD) method mediated by dicyandiamide using iron-based nanoparticles as catalysts was proposed to enhance the utilization of vertical channels in wood-based carbon electrodes and improve their pore structure and chemical composition. This approach aimed to fabricate composite electrodes with enhanced mass loading, interwoven conductive carbon nanotube networks, well-developed hierarchical porous structure, and abundant nitrogen/oxygen-containing functional groups. The effect of CVD temperature on the physical/chemical properties and capacitance performance of the composite material was investigated. Consequently, the optimal electrode (CW/NCNTs-800) attained a competitive initial specific capacitance of 5762 mF cm(-2) at 5 mA cm(-2) and demonstrated a satisfactory rate performance with the specific capacitance of 3520 mF cm(-2) at 300 mA cm(-2). In addition, the durable electrode demonstrated commendable cycle stability, maintaining a capacitance retention of 93 % through 30,000 cycles at 30 mA cm(-2). This study on wood-derived high mass-loading supercapacitor electrodes can provide a novel perspective on the application of high-performance energy storage devices.