Phenolic Resin‐Reinforced Porous Carbon Composite Phase Change Materials for Efficient Electro‐Thermal Conversion

ABSTRACT With growing global energy demand and carbon neutrality goals, efficient thermal energy storage is essential. Phase change materials (PCMs) like polyethylene glycol (PEG) offer high latent heat and energy storage capacity, but face issues like low thermal conductivity and leakage. Porous carbon from biomass (e.g., straw) is an ideal PEG carrier, yet enhancing its mechanical strength, thermal conductivity, and electrothermal conversion remains challenging. In this study, straw‐derived porous carbon was prepared via high‐temperature carbonization, and high‐loading PEG composite PCMs (with a loading capacity exceeding 88 wt%) were fabricated. Pretreatment with phenolic resin solution enhanced performance. Results show significant improvements in thermal conductivity, electrothermal conversion efficiency, and mechanical strength. The composite with 20% phenolic resin achieved a compressive strength of 1.85 MPa, and the corresponding PCM had a thermal conductivity of 0.83 W/(m K). This composite PCM shows promise for thermal energy storage, management, and electrothermal conversion applications.