Synthesis of three-dimensional Co3O4-carbon composite electrode materials with nanoporous structure for high-energy density supercapacitors

The metal oxide composites derived from metal-organic frameworks (MOFs) are ideal electrode materials for supercapacitors; however, their application in supercapacitors is limited by their uneven dispersion and poor electrical conductivity. Herein, wood nanofibers were employed as raw materials to load metal oxides derived from ZIF-67 using a simple and eco-friendly method and prepare a composite electrode material with a threedimensional network structure (CCAZ). This electrode material exhibited excellent specific surface area (567.19 m2/g) and pore volume (0.179 cm3 g- 1). Its specific capacitance reaches 574.44 F/g when the current density is 1 A/g, and it demonstrates good cyclic stability. An assembled double-electric layer capacitor demonstrates a power density of 100 W kg- 1 and an energy density of 6.01 Wh kg- 1. These findings offer new insights for improving the performance of wood nanofiber-based supercapacitors.