(568a) Simultaneous Impregnation and Encapsulation of Silica Gel with Salt Hydrates for Thermal Energy Storage Applications

Several materials have been tested for thermal energy storage so far. The energy storage density for salt hydrates in host matrix is high. However, the salt hydrates, especially LiCl and CaCl₂ are not stable in host matrix due to low deliquescence relative humidity. The current paper focuses on the simultaneous impregnation and encapsulation of silica gel matrix with salt hydrates for thermal energy storage applications. Methyl cellulose was used as the encapsulating agent to encapsulate salt hydrate and silica gel. The thermal energy storage properties were measured using a lab scale thermal energy storage setup. An energy storage density of 241 kWh/m³ (0.87 GJ/m³) and specific energy of 630 Wh/kg (2268 kJ/kg) were achieved. The cyclic properties of the prepared materials were also tested and they were found to be very stable. These composites were also characterized with Scanning Electron Microscopy, which showed the stable morphology and porous structure.