Economical preparation of high-performance activated carbon fiber papers as self-supporting supercapacitor electrodes

The cellulose-based paper electrode has attracted increasing attention for wearable and portable electronic devices. However, the loading of expensive electroactive substances, a large proportion of cellulose matrix and the loss of mechanical flexibility limit its commercial application. This article reports a facile and economical strategy for fabricating high-performance cellulose-based activated carbon fiber papers (ACFPs), which can be used as self-supporting supercapacitor electrodes without any binder. Combining wet papermaking, thermal carbonization, and double activation, the new strategy enables the in-situ transformation of fibrillated pulp fibers into cellulose-derived activated carbon fused with carbon fibers (CFs). The resulting ACFPs are characteristic of high specific surface area (808–1106 m²/g), high conductivity (1640–1786 S/m), prominent tensile strength (4.6–6.4 MPa), and flexible processability. Furthermore, the ACFP exhibits maximum specific capacitance of 48.8F/cm³ (or 165F/g) based on the whole electrode and possesses superior cycling stability. Moreover, electroactive materials are readily loaded onto the ACFPs to enhance the capacitance further. In the ACFPs, the cellulose-derived activated carbon is primarily responsible for capacitive energy storage, while CFs serve as a highly functional network due to their low thermal expansion coefficient and high electrical conductivity. Overall, this work provides a novel strategy for manufacturing scalable, cost-effective paper-based electrode materials with broad application prospects in energy storage.