Wooden electrothermal composites for fast electrothermal conversion†

Abstract

Thermal energy plays a vital role in human civilization. MXene has attracted considerable attention due to its high electrothermal conversion efficiency and rapid electrothermal response, making it suitable for thermal management applications. However, the stacking of MXene layers may reduce its electrothermal conversion performance. In this study, we report a strategy to impregnate MXene into ultra-thin delignified wood films. The porous structure of the ultra-thin wood film promoted uniform and homogeneous impregnation of MXene. The oriented cellulose fibrils facilitated the aligned assembly of MXene, which regulated its stacking behavior and contributed to the formation of continuous electrical transport pathways. Subsequently, hot-pressing of multi-layer wood films improved the total MXene loading capacity through densification and provided dense, continuous electrical transport pathways. The resulting wooden electrothermal composite exhibited excellent electrical conductivity (2548 S m⁻¹) and fast electrothermal conversion, reaching 180 °C at 4 V within 60 s. Meanwhile, the composite demonstrated good flame retardancy due to phytic acid/chitosan (PA/CS) treatment, ensuring safety at elevated temperatures. Wooden electrothermal composites with rapid electrothermal response and enhanced fire safety have broad application potential in household heating, energy conversion, and other applications.