Thermochemical energy storage drastically enhanced by zirconium oxide and lithium hydroxide for magnesium hydroxide

Abstract Energy storage provides sustainable energy. Magnesium hydroxide (Mg(OH) 2 ) is a promising material for thermochemical energy storage. Zirconium oxynitrate (ZrO(NO 3 ) 2 ) and lithium hydroxide (LiOH) are investigated to improve the heat‐storage efficiency of Mg(OH) 2 . Experimental results indicate that the heat‐storage rate can be significantly increased by 306‐fold. The dehydration conversion can be increased up to 99% with 122‐fold increase in 15.3 min. The onset temperature of Mg(OH) 2 dehydration decreases from 337 to 228°C. The activation energy of Mg(OH) 2 dehydration significantly reduces by 57.7%. The cycle ability of heat storage and heat release also remarkably improves. Moreover, the heat‐storage time significantly decreases. The crystal parameters, crystal volume, and platelet size of Mg(OH) 2 notably diminish. The acting mechanism of these additives is proposed using high‐resolution transmission electron microscopy, X‐ray powder diffraction, and X‐ray photoelectron spectroscopy data. Moreover, the kinetic equations for the dehydration of excellent Mg(OH) 2 composites are disclosed for computing simulation.