Strategies for the enhancement of heat storage materials performances for MgO/H2O/Mg(OH)2 thermochemical storage system

MgO/H2O/Mg(OH)2 thermochemical storage system is still at an early stage of development and several research efforts are accomplished to bring this technology at an applicative stage. The material development is the key point for the system implementation. Among the investigated strategies, the synthesis route for the preparation of Mg(OH)2 over a carbonaceous support, i.e. exfoliated graphite (EG), significantly affect the stability of the hybrid material and its thermochemical performances. In this study the influence of the preparation method, namely Deposition-Precipitation and Reverse Deposition-Precipitation, on the morphology and thermochemical performances of EG/Mg(OH)2 hybrid materials have been investigated. Among the overall investigated samples, EG/Mg(OH)2 obtained by Deposition-Precipitation and Reverse Deposition-Precipitation realized through one shot addition of the precipitating agent and at 0 C allow to achieve the best thermochemical performance. As main result a storage heat value of 1166, 1163 and 1080 kJ/kgMg(OH)2, respectively, has been obtained.