Preparation and characteristic of high thermal conductivity, low-cost biomimetic layered carbonized bamboo-based composite phase change material

Abstract

Shape-stable composite phase change materials (CPCMs) are essential for temperature regulation and mitigating the instability and fluctuations in renewable energy transmission. However, there is a pressing demand for low-cost, shape-stable CPCMs with high thermal conductivity and substantial latent heat. In this work, a simple novel method involving hot pressing, cutting, assembling and carbonization is developed to prepare new layered carbonized bamboo sheets (LCBSs) skeleton materials. Then, biomimetic layered carbonized bamboo-based composite phase change materials (LCB-CPCMs) are prepared by impregnating paraffin wax (PW) into the LCBSs. LCBSs with macroscopic, mesoscopic and microscopic pore structures, high specific surface area and high thermal conductivity are used as matrices for the first time. Compared to carbon nanotubes, graphene and other carbon materials, LCBSs are more cost-effective and support a high PW loading of 72.7 %. Differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) confirm that LCB-CPCMs exhibit outstanding thermal reliability, stability, and high latent heat. Moreover, the axial thermal conductivity of layer pristine bamboo sheets (LPBSs), LCBSs, and LCB-CPCMs is higher than the radial conductivity. Notably, the axial thermal conductivity of LCB-CPCM at 55 °C reaches 0.835 W·m⁻¹·K⁻¹, exceeding that of pure paraffin by 157 %. Infrared thermography thermal response tests further demonstrate the superior performance of LCB-CPCMs in thermal energy storage and regulation. This research presents a novel, high-quality matrix material suitable for developing shape-stable CPCMs with high latent heat and thermal conductivity. It has promising applications in the field of thermal energy storage and management.