Abstract We fabricated a nanoarray-modified nickel foam utilized as the supporting material for polyethylene glycol (PEG) to prepare a form-stable phase change material (PCM). The nanoarrays on the skeleton of the nickel foam look like flowers and can act as the nucleating agent, giving rise to the heterogeneous nucleation of the material. The nanoarray-modified nickel foam-supported PCM (NAPCM) has high latent heat values, which are 132.1 and 135.8 J·g−1 in the melting and solidification processes respectively, showing outstanding thermal energy storage capacity. The thermal properties including the latent heat values of the NAPCM after 100 times of thermal cycling are almost unchanged compared with the original one. Moreover, the thermal conductivity of the NAPCM increases by 157.4% and the super cooling degree decreases by 35.3% compared with pure PEG. The NAPCM with low super cooling, high latent heat values and thermal conductivity shows great potential for thermal energy utilization.