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

Ryo Kurosawa; Masato Takeuchi; Junichi Ryu

doi:10.1021/acsomega.9b02189

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

ACS Omega. 2019 Oct 17;4(18):17752-17761. doi: 10.1021/acsomega.9b02189. eCollection 2019 Oct 29.

Authors

Ryo Kurosawa¹, Masato Takeuchi², Junichi Ryu¹

Affiliations

¹ Graduate School of Engineering, Chiba University, 1-33, Yayoi-cho, Inage-ku, Chiba 263-8522, Japan.
² Department of Applied Chemistry, Graduate School of Engineering, Osaka Prefecture University, 1-1, Gaku-en-cho, Naka-ku, Sakai, Osaka 599-8531, Japan.

Abstract

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.