Simultaneous enhancement of latent heat and thermal conductivity of docosane-based phase change material in the presence of spongy graphene

•The PCM composite consisting of docosane and spongy graphene (G22) is prepared.•The latent heat and thermal conductivity of G22 are simultaneously increased.•The latent heat increase is due to formation of docosane with higher crystallinity.•Graphene sheets act as a nucleating agent to enhance the docosane crystallinity.

The effects of spongy graphene on the latent heat and thermal conductivity of the phase change material consisting of docosane and spongy graphene were studied. The latent heat and thermal conductivity of docosane/graphene composites were simultaneously enhanced in contrast to that of pure docosane. The latent heat increased from 256.1 J/g to 262.8 J/g, and the thermal conductivity increased more than 2 times in a low graphene concentration of ~3 mg/cm3. X-ray diffractometer, scanning electron microscopy, and Fourier-transform infrared spectrometer were used to characterize the microstructure of docosane and docosane/graphene composite. It is found that the crystallinity of layered docosane was enhanced in the presence of spongy graphene sheets acting as a nucleating agent, which resulted in the increase of latent heat. The enhancement of thermal conductivity for docosane/graphene composite is attributed to the high thermal conductivity of graphene.

Graphical abstractThe simultaneous enhancement of latent heat and thermal conductivity of docosane/graphene composite is attributed to the formation of layered docosane with higher crystallinity in the presence of spongy graphene sheets acting as a nucleating agent.Figure optionsDownload full-size imageDownload as PowerPoint slide