Solid gas and electrochemical hydrogenation of the selected alloys (R’,R’’)2-xMgxNi4-yCoy (R’, R’’ = Pr, Nd; x = 0.8–1.2; y = 0–2)

• Published in: Journal of alloys and compounds 2021-09, Vol.876, p.1, Article 160155
• Main Authors: Verbovytskyy, Yuriy, Oprysk, Volodymyr, Paul-Boncour, Valérie, Zavaliy, Ihor, Berezovets, Vasyl, Lyutyy, Pavlo, Kosarchyn, Yuriy
• Format: Article
• Language: English
• Subjects: Discharge; Electrochemical properties; Hydrides; Hydrogenation; Magnesium; Rare earth alloys; Rare earth and magnesium alloys; Sintering (powder metallurgy); Solid solutions; X ray powder diffraction
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2021.160155

•The formation of solid solution for the (R’,R’’)2-xMgxNi4-yCoy (R’, R’’ = Pr, Nd; x = 0.8–1.2; y = 0–2) alloys has been observed.•Influence of Pr/Nd, R/Mg and Ni/Co ratio on the solid-gas hydrogenation of the alloys has been studied.•The electrochemical charge–discharge parameters of the alloys has been determined. [Display omitted] A number of alloys with the (R’, R’’)2-xMgxNi4-yCoy (R’, R’’ = Pr, Nd; x = 0.8–1.2; y = 0–2) compositions were synthesized by the sintering method and characterized by X-ray powder diffraction method. They are all with cubic MgCu4Sn structure and belong to the continuous solid solution. Gas hydrogenation was performed for the selected alloys and 15 new hydrides belonging to cubic or orthorhombic structures were obtained. PCT diagrams are constructed for the Nd1.2Mg0.8Ni3Co - H2 and Nd0.8Mg1.2Ni3Co - H2 systems. The influence of R/Mg and Ni/Co substitution on the discharge characteristics of the (R’, R’’)2-xMgxNi4-yCoy electrodes was studied. It was established that cobalt-doped alloys with high magnesium content show the highest discharge capacities.