An innovative wood derived carbon-carbon nanotubes-paraffin wax phase change material with excellent thermal conductivity and latent heat of phase change

Phase change materials (PCM) have evolved over time and gradually adapted to the emerging needs of society. Their excellent properties, such as high latent heat storage capacity and fast response time, have aroused tremendous interest in applications such as thermal management systems, building energy efficiency, communications, and power. However, drawbacks such as low thermal conductivity, susceptibility to leakage, and small latent heat of phase transition limit the practical application of PCM. In this work, an innovative wood derived carbon-carbon nanotubes-paraffin wax (WDC-CNTs-PW) phase change energy storage composite is prepared by the high-temperature carbonization process, injection chemical vapor deposition, and vacuum impregnation method. The enhanced thermal conductivity of WDC-CNTs-PW is mainly due to the three-dimensional porous structure of WDC and the homogeneous introduction of the thermally enhanced filler CNTs. The axial and radial thermal conductivities of WDC-CNTs-PW are 0.35 and 0.29 W·m⁻¹·K⁻¹, respectively. The enthalpies of melting and crystallization of WDC-CNTs-PW are 142.02 and 136.14 J·g⁻¹, respectively, with impregnation efficiency of 70.95% and loading ratio of 73.01%. With excellent thermal conductivity, latent heat of phase transition, and encapsulation property, WDC-CNTs-PW opens up a surprising strategy for PCM applications in areas such as high technology microelectronics and energy-saving in houses.