Comparison of the Effect of Coaddition of Li Compounds and Addition of a Single Li Compound on Reactivity and Structure of Magnesium Hydroxide


R. Kurosawa, M. Takeuchi and J. Ryu, ACS Omega, 4, 17752-17761 (2020).

Mg(OH)2 is a chemical heat storage material that is studied for the utilization of 300–350 °C waste heat. In this study, LiCl and LiOH were coadded to Mg(OH)2, and the reactivity and structural evolution were investigated. In the hydration of samples at 200 °C subsequent to dehydration at 270 °C, Mg(OH)2 with coadded LiCl and LiOH showed excellent hydration reactivity, with a heat output density of 1053 kJ kg–1. The coaddition of LiCl and LiOH enhanced both the dehydration and the hydration reactivity of Mg(OH)2. X-ray diffraction analysis indicated that the addition of LiOH to Mg(OH)2 promoted the decomposition of Mg(OH)2 and the diffusion of water on the surface of Mg(OH)2, whereas the addition of LiCl to Mg(OH)2 promoted these processes in the bulk phase of Mg(OH)2.