TY - JOUR AU - Verbovytskyy, Yu. V. AU - Zavaliy, I. Yu. AU - Berezovets, V. V. AU - Lyutyy, P. Ya. PY - 2020/09/30 Y2 - 2024/03/29 TI - Solid gas and electrochemical hydrogenation properties of the R1-xR’xMgNi4-yCoy (R, R’ = Y, La, Ce) alloys: Array JF - Physics and Chemistry of Solid State JA - Phys. Chem. Sol. State VL - 21 IS - 3 SE - Scientific articles DO - 10.15330/pcss.21.3.503-509 UR - https://journals.pnu.edu.ua/index.php/pcss/article/view/4133 SP - 503-509 AB - <p>New R<sub>1-<em>x</em></sub>R’<em><sub>x</sub></em>MgNi<sub>4-<em>y</em></sub>Co<em><sub>y</sub></em> (R, R’ = Y, La, Ce; <em>x</em> = 0.5; <em>y</em> = 0, 1, 2) alloys have been synthesized by powder sintering method, and their crystal structure and hydrogen storage properties have been studied. X-ray diffraction analysis showed that R<sub>1-<em>x</em></sub>R’<em><sub>x</sub></em>MgNi<sub>4-<em>y</em></sub>Co alloys belong to the MgCu<sub>4</sub>Sn-type structure. The synthesized alloys absorb hydrogen at room temperature and hydrogen pressure 0.1-10 bar. For some of the studied compounds, the formation of hydrides with cubic and orthorhombic structures was found. Highest hydrogen content is found for the Co-rich compounds: La<sub>0</sub><sub>.5</sub>Y<sub>0</sub><sub>.5</sub>MgNi<sub>2</sub>Co<sub>2</sub>H<sub>5.18</sub> and La<sub>0</sub><sub>.5</sub>Ce<sub>0</sub><sub>.5</sub>MgNi<sub>2</sub>Co<sub>2</sub>H<sub>6.48</sub>. Electrochemical studies showed that Y-based electrode materials exhibit better electrochemical performance comparing with Ce-doped ones. Highest discharge capacity of 292 mА∙h/g was observed for La<sub>0.5</sub>Y<sub>0.5</sub>MgNi<sub>3</sub>Co, but the best cyclic stability after 50<sup>th</sup> cycle of 92% was seen for La<sub>0.5</sub>Y<sub>0.5</sub>MgNi<sub>2</sub>Co<sub>2</sub>. Additionally, obtained results of the electrochemical properties were compared with related compounds. High rate dischargeability of Co-free alloys at I = 1 A/g were twice higher than ones containing cobalt.</p> ER -