Effect of rare earth hydrides on hydrogen absorption and desorption properties of CeMgNi hydrogen storage alloy

Abstract

This study focuses on the preparation of the CexMg_2-xNi hydrogen storage alloy (where x = 0, 0.2, 0.3, 0.4, 0.5) through the method of vacuum induction melting. The research examined the influence of varying Ce concentrations on the characteristics of the Mg₂Ni hydrogen storage alloy. The phase structure and microstructure of the synthesized alloys were characterized through X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The kinetic and thermodynamic characteristics of samples subjected to various environmental conditions were assessed using a PCT tester. Additionally, DSC curves for samples heated at rates of 5 K/min, 10 K/min, 15 K/min, and 20 K/min were obtained through TG. The results indicated that the CeMgNi₄ phase, which arises from the partial substitution of Mg with Ce, did not engage in the hydrogen absorption and desorption processes, leading to a reduction in hydrogen storage capacity to a certain extent. Nevertheless, The enhancement of the overall hydrogen storage performance of the CeMgNi hydrogen storage alloy was significantly correlated with the increased content of the CeMgNi₄ phase.