Microstructure and hydrogen storage properties of Mg-Ni-Ce alloys with a long-period stacking ordered phase

Improved Absorption and Desorption Kinetics of Mg–Ni–Ce Alloy Activated under Elevated Hydrogen Pressure

“…The detailed preparation process has been described elsewhere. 30,31) In short, it can be summarized as melting Mg ingot, Ce ingot and MgNi intermediate alloy in graphite crucible under the protection of covering agent (RJ-6) in the resistance furnace. To obtain near equilibrium solidification, furnace cooling was performed.…”

“…It has been reported that the LPSO phase is unstable during high energy ball milling and subsequent hydrogenation processes. 20,30,41) It has been found in MgNiY system that the 18R-type LPSO phase decomposes into ultrafine YH 2 , MgH 2 and Mg 2 Ni phases during the first hydrogenation process by in-situ synchrotron X-ray diffraction and TEM. 20) Although LPSO phase is unstable during hydrogen absorption process and the decomposition is irreversible, it can make Mg, Ni and Ce elements distribute uniformly at the atomic scale during solidification process, and can decompose into ultrafine catalytic phases after hydrogenation, promoting hydrogen absorption and desorption.…”

“…CeH 2.73 remains unchanged in subsequent hydrogenation and dehydrogenation processes, while Mg 2 Ni can release and absorb hydrogen again. 30) Figure 4(a) shows the SEM/BSE image of as-activated particle which is activated at 300°C under an initial hydrogen pressure of 3 MPa. Abundant secondary phase particles with particle size in the range of 1³3 µm are clearly observed on the surface of MgH 2 matrix.…”

Significant decrease of hydride decomposition enthalpy in ordered Mg-In alloys induced by growing hydrogen concentration

“…New Mg-based hydrogen storage materials (HSMs) with LPSO were investigated, e.g., in [23,[27][28][29][30][31][32][34][35][36]. Their interaction with hydrogen was studied, e.g., in [22,29,30,32,37,38]. Possible facilitation of HS in LPSO structures was reported, e. g., in [30,31,37], where the authors showed that complex several-stage sorption reactions running in HSM with LPSO could decrease overall energy budget of the sorption process as a whole.…”

“…Their interaction with hydrogen was studied, e.g., in [22,29,30,32,37,38]. Possible facilitation of HS in LPSO structures was reported, e. g., in [30,31,37], where the authors showed that complex several-stage sorption reactions running in HSM with LPSO could decrease overall energy budget of the sorption process as a whole. The beneficial effect of LPSO is not straightforward.…”