Three-dimensional hybrid material constructed by cellulose nanofibers/ multiwall carbon nanotubes aerogel and foam nickel and its electrochemical capacitance performance

Three-dimensional (3-D) electrode materials are ideal candidates for use in fabricating high-performance supercapacitors, owing to their unique network structure and excellent electrochemical properties. Although cellulose nanofibers (CNF) and multiwall carbon nanotubes (MWCNT) are widely used in the development and design of electrode materials, how to use their unique one-dimensional nanostructures and inherent physical properties to build high-performance 3-D electrode materials remains a huge challenge. Herein, an aerogel film produced by the freeze-drying self-aggregation of MWCNTs and CNFs was used as the “filling,” and an inter-connected 3-D network of nickel foam (NF) as the “framework,” for well-design and fabrication of an MWCNT/CNF-NF hybrid materials (named as MCN). Benefiting from the excellent conductivity and high specific surface area of the MCN, it is exceptionally suitable for use as the electroactive material platform in the fabrication of high-performance electrodes. Therefore, in this work, the high-performance PPy-MCN freestanding electrodes were successfully prepared by optimizing the time of the electroactive material polypyrrole. As expected, the electrode exhibits a high areal capacity of 2217.8 mF·cm⁻² (=869.9 F·g⁻¹) at a current density of 5 mA·cm⁻², with good stability even after 3000 charge-discharge cycles.