Shape-stabilized phase change materials based on porous supports for thermal energy storage applications

Phase change materials (PCMs) are widely utilized in latent thermal energy storage and thermal management systems due to their high-energy storage density, high latent heats and excellent capabilities of maintaining almost constant temperature. However, the formidable challenge still seriously limited the performance of PCMs in thermal energy storage systems, such as their leakage and low thermal conductivities. Therefore, appropriate approaches to construct shape-stabilized PCMs (ss-PCMs) and effectively enhance the thermal conductivities are importantly necessary to realize the practical applications of PCMs. Porous supports packaged PCMs provide an effective route for constructing ss-PCMs with enhanced thermal conductivity, mechanical strength, chemical stability and flame resistance. In this review, we aim to assess the advantages/disadvantages of porous materials via summarizing the key research progress on the porous materials (e.g., metal foams, expanded graphite, graphene aerogels, carbon nanotubes, porous minerals, mesoporous silica, etc.) as ss-PCMs supports. The effects of pore size and geometry, surface modification, interaction forces, compositions, etc. on the phase change behaviors of ss-PCMs are summarized and discussed in detail by comparing the different porous materials. We believe that the summary and discussion in the review will lead to a better understanding on the designing and constructing of efficient ss-PCMs, and even shed light on the design for novel porous materials supported ss-PCMs based on the discovered interactions between the porous supports and PCMs. Finally, the future research topics and challenges on porous materials for ss-PCMs development are also prospected with emphasizing on the emergence of new design of porous materials with improved thermal conductivity, high PCMs loading amount and high thermal latent for practical applications.