Membrane-encapsulated salt hydrate: An anti-agglomeration approach to enhance cyclability

Heat has a crucial effect on the general energy consumption in the world. Hence, the need for an environmentally
friendly and energy-efficient substitute is on the rise as far as reducing carbon footprints is concerned, where
thermochemical materials (TCM) can be a viable option. Potassium carbonate (K2CO3) has shown the most promising
characteristics for seasonal heat storage due to its high energy density, cost-effectiveness, and reaction safety.
However, due to the accruing of salt crystal clumping after a few hydration/dehydration cycles, the operational life
cycle of K2CO3 is challenged with diminished energy density and kinetics of hydration. In the present study, to
mitigate this challenge, a new encapsulation strategy based on membrane science is used to address both
agglomeration mitigation and preservation of crystal integrity without limiting the water vapour diffusion inside the
crystal by employing a separative polymeric layer. This research introduced the encapsulation process along with
suitable crystal morphology with a focus on optimal pore structure and hydration kinetics as a mechanism for
optimizing the efficiency of transport of water vapour. The key results of this research provide a cheap and easy-to-implement
method to prevent agglomeration while preserving the cyclic performance characteristics of salt hydrates
for heat battery application.