Polypyrrole-coated conjugated microporous polymers/expanded graphene carbon aerogels based phase change materials composites for efficient energy conversion and storage

Phase change materials (PCMs) composites are of great importance for a wide range of applications in energy conversion and storage, waste heat recovery and utilization, thermal energy management in building, electronic devices cooling and heat insulation, etc. Herein, a novel strategy for the fabrication of PCM composites for solar/ electro energy conversion and storage is reported. The polypyrmle (PPy) coated conjugated microporous polymers/expanded graphene (EG) carbon aerogels/HDA (PCMPECAs/HDA) composites were firstly obtained via Sonogashira-Hagihara cross-coupling reaction followed by a carbonization treatment, PPy coating and finally 1-Hexadecylamine (HDA) impregnation. The introduction of EG and PPy was to improve the porosity, thermal conductivity and photothermal performance. The resultant PCMPECAs/HDA composites exhibited excellent comprehensive performances, including relatively high thermal conductivity of up to 234.0% that of HDA, high energy storage density up to 205.10 kJ/kg, excellent shape and thermal stability and a remarkable photothermal conversion and storage efficiency of up to 93.5%, respectively. And after 300 times thermal and cooling cycles, the latent heat of PCMPECAs/HDA still remains up to 150.20 kJ/kg. Besides, the resultant composites also manifest excellent electm-thermal effect at low voltage. Due to the aforementioned advantages, PCMPECAs/HDA composites possess great potential applications in solar/electric energy conversion and storage.