Carbon nanotubes modified graphene hybrid Aerogel-based composite phase change materials for efficient thermal storage

Phase change materials (PCMs) have attracted more and more attention in the field of latent heat storage. In order to solve the leakage behavior and improve heat transfer performance of polyethylene glycol (PEG), a method of self-assembled hybrid aerogel filled with carbon nanotubes (CNTs) combined with reduced graphene oxide (rGO) nanosheets is proposed herein. The as-prepared CNTs-graphene hybrid aerogel (CGA) with three-dimensional porous structure can be used as a highly adsorptive and stable carrier for PCM. After the vacuum impregnation process, a high-performance PEG/CGA composite PCMs (c-PCMs) is obtained, which exhibits an outstanding PEG loading ratio of 97.6 %. Moreover, after 1000 repeated heating/cooling cycles, the HM and HS value of PEG/CGA c-PCMs remained 93.44 % and 92.84 %. Meanwhile the PEG/CGA c-PCMs remains intact and the loading ratio could still maintain as high as 96.4 %, which proved that PEG/CGA c-PCMs presented reliable thermal cycling stability. The PEG/CGA c-PCMs only takes 603 s to raise from 30 ℃ to 70 ℃, which is much faster than that of pure PEG (813 s) and PEG/GA composite (727 s). And The thermal conductivity of PEG/CGA(0.586 W/(m∙K)) was 186 % times than that of pure PEG(0.314 W/(m∙K)).The introduction of CNTs can not only enhance the adsorption capacity of c-PCMs and alleviate the leakage of PEG, but also improve the heat transfer performance of c-PCMs. These results specify that PEG/CGA c-PCMs can be used as remarkable and stable energy storage materials for environmental thermal management systems.