Aramid Nanofibers Aerogel-filled Wood-based Carbon Material for Flexible Solid Supercapacitors

Delignified wood-based carbon material is a potential cost-effective and environmentally-friendly flexible electrode material. However, the abundant intertubular cavities not only endow excellent flexibility, but also inevitably deteriorate the conductivity, integrity and areal density of the delignified wood-based flexible carbon material, which is not conducive to improve the energy storage performance. In this work, an aramid nanofiber-based carbon aerogel was filled in the intertubular cavities via a series of processes, including filled by virtue of the unidirectional capillary forces, gelation, freeze-drying and carbonization. The filled carbon aerogel can significantly increase the conductivity and the sheet resistance is as low as about 28 +/- 5 omega sq(-1). The filled carbon aerogel does not deteriorate its excellent energy storage behavior derived from the unique low-tortuosity and open slender tubular microstructure. The filled carbon aerogel can improve the space utilization of the delignified wood-based carbon. The areal specific capacitance has been increased from 20.8 to 51.9 mF cm(-2) at a current density of 50 mu A cm(-2). The area specific capacitance still remains at 33.9 mF cm(-2) when the current density increased to 1000 mu A cm(-2). The aramid nanofibers aerogel-filled wood-based carbon flexible interdigitated solid supercapacitors also exhibit excellent flexibility and folding endurance.