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 similar to 3 mg/cm(3). 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 grapheme. (C) 2014 Elsevier B.V. All rights reserved.