Rapid Processing of Holocellulose-Based Nanopaper toward an Electrode Material

Developing a flexible, lightweight, and sustainable electrode with low impedance, electromagnetic stability, long cycle life, and operational safety is essential for meeting the urgent demands for wearable and flexible equipment in contemporary society. Herein, we demonstrate a simple and scalable method to fabricate a high-performance and low-cost nanopaper based on holocellulose nanofiber and multiwalled carbon nanotubes in aqueous by vacuum filtration. Compared with cellulose-based nanopaper, the holocellulose-based nanopaper has distinct advantages such as being easy to fabricate, eco-friendly, and economical. The holocellulose nanofiber of wheat straw was obtained by a mechanical method which retained the natural core–shell structure with an ∼40 nm diameter and ∼3 μm length. Compared with cellulose-based nanopaper, the pure holocellulose nanopaper exhibited high toughness (1.97 × 104 kJ/m3). The fabricated holocellulose-based conductive nanopaper exhibited a desirable electrical performance, including an electric conductivity of 0.72 S cm–1, a high gravimetric capacitance of 271.99 F g–1 at a current density of 50 mA g–1, and cycling stability at a discharge current density of 100 mA g–1 under room temperature. In addition, the holocellulose-based nanopaper demonstrated good thermal and dimensional stability. The holocellulose-based nanopaper showed these advantageous features of high physical flexibility, good electrochemical properties, and excellent mechanical properties, which are desirable for flexible electrodes, supercapacitors, and sensors.