LAUSR

Abstract Thermochemical heat storage is an efficient energy storage technology to settle the problem in solar energy applications. In this paper, graphene oxide aerogel (GOA) stabilized MgCl2⋅6H2O composites with varying MgCl2⋅6H2O contents are prepared by typical hydrothermal and freeze drying methods. The effect of GOA on dehydration temperature of GOA-MgCl2⋅6H2O composites is investigated using differential scanning calorimetry (DSC). Due to nanosize effect and low crystallinity of MgCl2⋅6H2O on the inner surface of GOA based on the observation of XRD and TEM, main corresponding dehydration peaks of the curves move to lower temperature with the increase of GOA content in the composites. Compared with pure MgCl2⋅6H2O, the fourth endothermic peak temperature of the composites containing 50 wt% MgCl2⋅6H2O decreases by 90 °C. Till now, it is the first time that a new approach to manipulate the dehydration temperature of salt hydrates is reported. Meanwhile, the highest loading rate of MgCl2⋅6H2O reaches 90 wt%, at which energy density of the composites is accordingly as high as 1598 J/g. Thus GOA stabilized MgCl2⋅6H2O composites will play an important role in the field of low temperature thermochemical heat storage.