Thermally Conducting Microcellular Carbon Foams as a Superior Host for Wax‐Based Phase Change Materials

Thermally conducting microcellular carbon foams are prepared from sucrose with graphite as a filler using an economical, scalable, and sustainable NaCl particle templating technique. The effect of graphite filler and NaCl template loading on density, porosity, thermal conductivity, and microstructure are carefully investigated. Conducting carbon foams (CCF) exhibit high porosity (76.1 to 93.4%) and adequate compressive strength (0.225 to 14.96 MPa). The high thermal conductivity (0.282 to 5.23 W m−1 K−1), interconnected microcellular structure (cell size 2–12 μm), and hydrophobic nature make the foams ideal for hosting wax‐based phase change materials for thermal energy storage and management applications. Composites of conducting carbon foam and paraffin wax (PW) are prepared with various wax loadings (50.5 to 82.6 wt%), which exhibit thermal conductivities in the range of 0.65–7.72 W m−1 K−1. The melting and freezing characteristics and form stability of the composites are also studied. It is established that the microcellular structure is advantageous for easy wax‐impregnation and retention during thermal cycling compared to macrocellular (cell size of 600 μm) foams of the similar composition due to the enhanced capillary forces. Differential scanning calorimetry (DSC) study of PW/CCF composites shows the highest melting enthalpy of 110.9 J g−1. Microcellular conducting carbon foams (CCF) synthesized using NaCl templating method is used as effective host for phase change materials. A significant increase in the thermal conductivity is shown by the composites (0.65 to 7.72 W m‐1 K‐1) over pristine paraffin wax (0.24 W m‐1 K‐1). The microcellular structure of CCF enhances the capillary forces helping in wax retention during thermal cycling.