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

Xie, Lishuai; Xu, Man

doi:10.2320/matertrans.mt-m2019304

Cited by 3 publications

(2 citation statements)

References 43 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Therefore, varying the solute content in LPSO alloys is instrumental in the optimization of both hydrogenation kinetics and hydrogen storage capacity through the effective distribution of minimal alloy additions. However, most studies have focused on a single alloy composition and/or process condition [37][38][39][45][46][47][48][49].…”

Section: Introductionmentioning

confidence: 99%

Design of LPSO Phases in Mg-Y-Ni Alloys to Impact Hydrogenation Kinetics

Nicholson,

Skripnyuk,

et al. 2023

Hydrogen

View full text Add to dashboard Cite

A series of Mg-Y-Ni alloys with different volume fractions of long-period stacking-ordered (LPSO) phase were prepared, by controlling the alloy composition, heat treatment, and single-pass extrusion, to assess the influence of increasing LPSO phase volume fraction on the hydrogen absorption and desorption properties of the extruded alloys. The LPSO phase volume fraction in the alloys increased with increasing solute concentration, from ~24% LPSO in Mg97Y2Ni1 (at.%) to ~60% LPSO in Mg93Y4Ni3 (at.%) up to ~92% LPSO in Mg91Y5Ni4 (at.%). The most refined microstructure was obtained in the alloy with highest volume fraction of LPSO phase. After 100 s at 300 °C, the Mg91Y5Ni4 alloy absorbed 4.6 ± 0.2 wt.% H while the Mg97Y2Ni1 and Mg93Y4Ni3 alloys each absorbed 3.8 ± 0.2 wt.% H. After 10,000 s at 300 °C, all three alloys had absorbed a maximum of 5.3 ± 0.2 wt.% H with no further significant difference in hydrogen absorption kinetics. The Mg91Y5Ni4 alloy desorbed 1.8 ± 0.2 wt.% H after 100 s at 300 °C against a vacuum while the Mg97Y2Ni1 and Mg93Y4Ni3 alloys desorbed 0.8 ± 0.2 wt. H and 0.6 ± 0.2 wt.% H, respectively. After 10,000 s at 300 °C, the Mg91Y5Ni4 and Mg97Y2Ni1 alloys completely desorbed 5.2 ± 0.2 wt.% H and 5.4 ± 0.2 wt.% H, respectively, but the Mg93Y4Ni3 alloy desorbed only 3.7 ± 0.2 wt.% H. Hydrogen absorption and desorption kinetics were fastest in the Mg91Y5Ni4 alloy with the highest LPSO volume fraction, but no consistent trend with LPSO phase volume fraction was observed with the Mg93Y4Ni3 alloy, which showed the slowest absorption and desorption kinetics. The hydrogen pressures corresponding to metal–hydride equilibrium did not vary with LPSO phase volume fraction or alloy composition, indicating that the (de)hydrogenation thermodynamics were not significantly changed in any of the alloys. Hydrogen absorption experiments with thin foils, made of extruded Mg91Y5Ni4 alloy with the highest LPSO phase fraction, demonstrated that the LPSO structures decompose into Mg phase, Mg2Ni phase, lamellar Mg/Mg-Y structures, and YHx particles. This study shows that hydrogen kinetics can be impacted in Mg-Y-Ni alloys by controlling the LPSO phases using common metallurgical techniques.

show abstract

Section: Introductionmentioning

confidence: 99%

Design of LPSO Phases in Mg-Y-Ni Alloys to Impact Hydrogenation Kinetics

Nicholson,

Skripnyuk,

et al. 2023

Hydrogen

View full text Add to dashboard Cite

show abstract

“…Common methods to improve the hydrogen storage performance of MgH 2 include alloying [9][10][11][12][13][14][15][16][17][18], nanoconfinement [19,20], nano-crystallization [21][22][23][24][25][26], and catalyst doping [27][28][29][30][31][32][33][34][35]. Alloying of Mg by combining with other metal elements, such as Al, Ni, and Ge, can produce less stable Mg-based hydrides.…”

Section: Introductionmentioning

confidence: 99%

Enhanced Hydrogen Storage Performance of MgH2 by the Catalysis of a Novel Intersected Y2O3/NiO Hybrid

Liu

Wang

et al. 2021

Processes

View full text Add to dashboard Cite

MgH2 is one of the most promising hydrogen storage materials due to its high hydrogen storage capacity and favorable reversibility, but it suffers from stable thermodynamics and poor dynamics. In the present work, an intersected Y2O3/NiO hybrid with spherical hollow structure is synthesized. When introduced to MgH2 via ball-milling, the Y2O3/NiO hollow spheres are crushed into ultrafine particles, which are homogenously dispersed in MgH2, showing a highly effective catalysis. With an optimized addition of 10 wt% of the hybrid, the initial dehydrogenation peak temperature of MgH2 is reduced to 277 °C, lowered by 109 °C compared with that of the bare MgH2, which is further reduced to 261 °C in the second cycle. There is ca. 6.6 wt% H2 released at 275 °C within 60 min. For the fully dehydrogenation product, hydrogenation initiates at almost room temperature, and a hydrogenation capacity of 5.9 wt% is achieved at 150 °C within 150 min. There is still 5.2 wt% H2 desorbed after 50 cycles at a moderate cyclic condition, corresponding to the capacity retention of 79.2%. The crystal structure and morphology of the Y2O3/NiO hybrid is well preserved during cycling, showing long-term catalysis to the hydrogen storage of MgH2. The Y2O3/NiO hybrid also inhibits the agglomeration of MgH2 particles during cycling, favoring the cyclic stability.

show abstract