Highly Efficient and Durable Aramid Nanofibers/Carbon Nanotubes-Coated Electrothermal Paper

Flexible paper-based electrical heating materials loaded with electrically conductive fillers possess lightweight, high strength, desirable electrothermal efficiency, and impressive flexibility, showing broad application prospects in wearable smart clothing and electric heating films. However, the conventional electrothermal paper often suffers from undesirable electrical heating efficiency, nonuniform heat distribution, and increased input power. Herein, we report a flexible sandwich-structure aramid electrothermal paper by facile dual-coating approach with a small loading amount (∼6.0 wt %) of carbon nanotubes (CNTs) and aramid nanofibers (ANFs) on aramid base paper. The ANFs/CNT dispersion possesses desirable viscosity and constructs a large number of conductive paths on the paper surface, which enabled rapid heating at low voltage without the need for high conducting thresholds of carbon material incorporation. The obtained ANFs/CNT-coated paper (AC paper) exhibits excellent mechanical properties (a tensile strength of 35.6 MPa, a tear strength of 31.7 mN·m2·g–1, and a folding endurance up to 6754 times) due to the densely entangled ANF/CNT network. The resultant aramid electrothermal paper reaches a saturated temperature of 190 °C under an input voltage of 25 V, demonstrating potential application prospects in deicing and smart wearable heaters. This work provides a promising and easy-to-commercialize strategy for developing flexible electrothermal paper employed in wearable devices and flexible electric heating elements.