Synthesis and performances evaluation of the spindle-shaped calcium hydroxide nanomaterials for thermochemical energy storage

Thermochemical energy storage is a promising alternation in heat recovery application and concentrated solar power plants. The present work focuses on the influence of morphology and porosity of Ca(OH)2 nanomaterials on their thermochemical energy storage performances. Firstly, the Ca(OH)2 nanoparticles with the morphologies of spindle and hexagonal structure were synthesized by the deposition-precipitation method, and their performances were evaluated by thermogravimetric analysis together with three kinds of commercial nanoparticles. The BET tests demonstrate that the self-made spindle-shaped Ca(OH)2 has the highest BET-specific surface area and pore volume among these five nanomaterials. Secondly, the thermochemical energy storage performance evaluation of these materials showed that the spindle-shaped Ca(OH)2 exhibited the best heat storage and output capacities (about 1300 kJ/kg), thus bringing a convenient route in production of Ca(OH)2 with higher energy storage density. Finally, after ten dehydration/hydration cycles, the conversions of spindle-shaped Ca(OH)2 remained at above 70%.