Raw-Cotton-Derived N‑Doped Carbon Fiber Aerogel as an Efficient Electrode for Electrochemical Capacitors

The carbon fiber aerogel with a high surface area, as a promising ideal electrode for electrochemical capacitors (ECs), has attracted tremendous attention because it can offer a fast charge–discharge rate and an exceptional rate capability. However, there is still a big challenge to acquire highly porous fiber aerogel with elastic properties and good flexibility. Herein, N-doped porous carbon fiber aerogel (N-CFA) has been successfully fabricated using raw cotton as a fibrous template to obtain shaped aerogels. ZIF-8, in situ fabricated on the surface of cotton, played the role of an active agent and nitrogen source to create a rich porous structure with a certain nitrogen content. Benefiting from the macromonolith morphology with good flexibility, favorable mechanical durability, nitrogen doping, anda high specific surface area, the N-CFA exhibits excellent electrochemical performance with a high capacity of 365 F g–1 at a current of 0.5 A g–1 and a remarkable rate capability of 65.8% from 0.5 to 100 A g–1 as a binder-free electrode in ECs. Additionally, N-CFA also displays a high capacitance retention of 93.6% after 10000 consecutive cycles at 5 A g–1. The strategy may offer a low-cost and scalable method to produce high-performance N-doped carbon aerogels for electrodes from biomass.