Investigation of H Sorption and Corrosion Properties of Sm2MnxNi7−x (0 ≤ x < 0.5) Intermetallic Compounds Forming Reversible Hydrides - Archive ouverte HAL Accéder directement au contenu
Article Dans Une Revue Energies Année : 2020

Investigation of H Sorption and Corrosion Properties of Sm2MnxNi7−x (0 ≤ x < 0.5) Intermetallic Compounds Forming Reversible Hydrides

Résumé

Intermetallic compounds are key materials for energy transition as they form reversible hydrides that can be used for solid state hydrogen storage or as anodes in batteries. AB y compounds (A = Rare Earth (RE); B = transition metal; 2 < y < 5) are good candidates to fulfill the required properties for practical applications. They can be described as stacking of [AB 5 ] and [AB 2 ] sub-units along the c crystallographic axis. The latter sub-unit brings a larger capacity, while the former one provides a better cycling stability. However, AB y binaries do not show good enough properties for applications. Upon hydrogenation, they exhibit multiplateau behavior and poor reversibility, attributed to H-induced amorphization. These drawbacks can be overcome by chemical substitutions on the A and/or the B sites leading to stabilized reversible hydrides. The present work focuses on the pseudo-binary Sm 2 Mn x Ni 7−x system (0 ≤ x < 0.5). The structural, thermodynamic and corrosion properties are analyzed and interpreted by means of X-ray diffraction, chemical analysis, scanning electron microscopy, thermogravimetric analysis and magnetic measurements. Unexpected cell parameter variations are reported and interpreted regarding possible formation of structural defects and uneven Mn distribution within the Ni sublattice. Reversible capacity is improved for x > 0.3 leading to larger and flatter isotherm curves, allowing for reversible capacity >1.4 wt %. Regarding corrosion, the binary compound corrodes in alkaline medium to form rare earth hydroxide and nanoporous nickel. As for the Mn-substituted compounds, a new corrosion product is formed in addition to those above mentioned, as manganese initiates a sacrificial anode mechanism taking place at the early corrosion stage.

Domaines

Matériaux
Fichier principal
Vignette du fichier
2020_Madern_Energies_Sm2(Mn,Ni)7_thermo-corro.pdf (1.99 Mo) Télécharger le fichier
Origine : Fichiers éditeurs autorisés sur une archive ouverte
Loading...

Dates et versions

hal-02907299 , version 1 (07-10-2020)

Identifiants

Citer

Nicolas Madern, Véronique Charbonnier, Judith Monnier, Junxian Zhang, Valérie Paul-Boncour, et al.. Investigation of H Sorption and Corrosion Properties of Sm2MnxNi7−x (0 ≤ x < 0.5) Intermetallic Compounds Forming Reversible Hydrides. Energies, 2020, 13 (13), pp.3470. ⟨10.3390/en13133470⟩. ⟨hal-02907299⟩
36 Consultations
50 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More