Encapsulation of Salt Hydrates by Polymer Coatings for Low-Temperature Heat Storage Applications

Efficient and cheap storage of energy from renewable resources presents a key technology to facilitate the ongoing transition. Storing heat in thermochemical materials (TCMs), such as salt hydrates, provides promising concept meet this demand. TCMs can capture reversibly loss-free by relying on equilibrium hydration reactions salts. Persistent bottlenecks full-scale application are low mechanical resilience grains their tendency coagulate or dissolve when contact with water vapor. To overcome this, be encapsulated stabilizing polymer coating. Ideal coatings combine high vapor permeability reversible deformability minimize resistance for transport accommodate volumetric changes TCM during repetitive (de)hydration, respectively. Here, systematic study into applicability commercially available polymers coating is presented. Mechanical analysis wet-cup experiments freestanding films revealed that cellulose-based successfully ductility engineering demands domestic TCM-based applications. The validity using model system was confirmed encapsulating granular ethyl hydroxyl propyl cellulose fluidized bed retained an enhanced structural integrity (de)hydration cycles observed.