3D self-bonded porous graphite fiber monolith for phase change material composite with high thermal conductivity

Abstract

Thermal conductivity (TC), thermal conductivity enhancement (TCE) and thermal conductivity enhancement per volume fraction of the filler (TCEF) are the three main parameters for evaluating heat transfer augmentation effect of phase change materials (PCM) composites. However, at present, simultaneous modulating these three parameters for PCM composites still remain challenging. Herein, three dimensional (3D) self-bonded porous graphite fiber monolith (SBGFM) with “in-plane bonding” characteristics is constructed as TC enhancer for PCMs to simultaneously boost these three parameters. The “in-plane bonding” enables the graphite planes continued at the interface regions, which facilitates the phonon vibration at the boundaries to apparently reduce the interfacial thermal resistance (ITR). The optimized SBGFM-PCM composite delivers high TC of 36.49 W·m−1·K−1 at a loading of 20.7 vol%, corresponding to TCE of 152, and TCEF of 734 % per 1 vol% loading, which is the best ever reported for carbon fiber reinforced PCM composites. Our work provides a novel concept and valuable insights into the design of high performance PCM composites and beyond.