Innovative composite sorbent for thermal energy storage based on a SrBr2 ·6H2 O filled silicone composite foam

This paper reports about the first experimental activity on a composite material for thermal energy storage, based on a SrBr·6HO filled silicone foam. The morphological and thermal features of the composite with different salt content (i.e. between 40 wt.% and 70 wt.%) were investigated. The dehydration behavior was studied by thermo-gravimetric analysis. Furthermore, scanning electron and 3D optical microscopy were used to compare the cellular microstructure of the composite foams. The synthesized foams are characterized by a well-interconnected cellular structure with a three-dimensional porous network. This, together with the high permeability to water vapor of the matrix favors water vapor diffusion and allows the reaction of all the salt embedded in the matrix. The main advantages of the composite material were analyzed and compared to other composites in literature. Since the production process, especially for higher salt content, seemed not sufficiently effective, causing a reduced foaming ration and lower ability to incorporate the salt hydrate, possible improvements were proposed and discussed.