Investigation on the Anisotropic Electrothermal Performance of Wood-Based Graphene Electric Heating Composites

The unique material structure and pronounced anisotropy of wood bestow it with an array of remarkable properties, creating opportunities for designing functional materials. This study investigates the application of wood's anisotropic structure in temperature-controlled intelligent electric heating materials by preparing wood-based graphene electric heating composites (GNPs@EW). Graphene nanosheets (GNPs) are incorporated into a birch matrix (EW) to enhance the electrical and thermal conductivity of insulating wood. The integration of graphene with wood is confirmed through Fourier transform infrared spectrometer (FTIR) and X-ray diffractometer (XRD) analysis. The optimal composite (GNPs@EW₁) is prepared with graphene-to-anhydrous ethanol mass ratio of 1:1. The results demonstrate the influence of wood's anisotropy on the electrical and thermal conductivity of the composites, revealing superior performance in the axial direction compared to the tangential direction. The resistivity of GNPs@EW₁ along the axial direction decreases by 2.1–2.9 times relative to the tangential direction, and the temperature rise after energization at 6 V is 22–29 °C higher in the axial direction. Furthermore, GNPs@EW₁ exhibits thermal stability, enhanced axial mechanical properties, and temperature uniformity, establishing these superior axial properties as a foundation for the development of wood-based heating materials and innovative smart heating applications.