Enhanced thermal conductivity of copper‐doped polyethylene glycol/urchin‐like porous titanium dioxide phase change materials for thermal energy storage

A composite phase change material (PCM) of copper-doped polyethylene glycol (PEG) 2000 impregnated urchin-like porous titanium dioxide (TiO2) microspheres (PEG/TiO2) was successfully synthesised. The urchin-like porous TiO2 structures contain hollow cavities that can provide a high PEG loading capacity of up to 80 wt%. Copper nanoparticles were uniformly dispersed on the outer and inner surfaces of the 0.8PEG/TiO2 as additives to enhance the thermal conductivity of the composite PCM. The latent heat of the Cu/PEG/TiO2 porous composite PCM reached 133.8 J/g, and the thermal conductivity was 0.58 W/(mK), which was 152.2% higher than that of TiO2 and 38.1% higher than 0.8PEG/TiO2. Moreover, the Cu/PEG/TiO2 porous composite PCM has excellent thermal stability and reliability.