Annealing effect on phase composition and electrochemical properties of the Co-free La2MgNi9 anode for Ni-metal hydride batteries

Hu, Weikang; Denys, R.V.; Nwakwuo, Christopher C.; Holm, Thomas R.; Mæhlen, Jan Petter; Solberg, Jan Ketil; Yartys, V.A.

doi:10.1016/j.electacta.2013.02.064

Cited by 93 publications

(35 citation statements)

References 40 publications

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“…Crystallographic parameters for the LaMg 2 Ni 9 and La 2 MgNi 9 phases obtained in this work well agree with the published data [2,3] and [8], respectively. Because of the large differences in atomic radii (r Mg = 1.602 Å vs. r La = 1.897 Å; r Pr = 1.81 Å; r Nd = 1.79 Å), increase in the Mg/RE ratio leads to a continuous decrease of both unit cell parameters, a and c, and volumes of the unit cells (see Figure 1).…”

Section: Compounds Re 3−x Mg X Ni 9 (Re=la Pr Nd) With Various Re/msupporting

confidence: 89%

“…This work included (a) Systematic studies of the influence of magnesium on the crystal structure and hydrogenation behaviour of the PuNi 3 -type La 3−x Mg x Ni 9 (x = 0-2) intermetallic alloys [5]; (b) Neutron powder diffraction studies of the La 2 MgNi 9 D 13 deuteride, which witnessed local hydrogen ordering, with hydrogen sublattice built from the MgH 6 octahedra and NiH 4 tetrahedra [6]; (c) Probing the effect of magnesium content and quenching rate on the phase structure and composition of the rapidly solidified La 2 MgNi 9 metal hydride battery electrode alloy [7]; (d) Investigations of the interrelation between the high temperature annealing and phase composition and electrochemical properties of the Co-free La 2 MgNi 9 anode for the Ni-metal hydride batteries [8]; (e) Studies of the effect of La substitution by Nd on the phase-structural transformations in the RE 2 MgNi 9 -H 2 systems; and (f) In situ neutron powder diffraction studies of the charge-discharge processes in the metal hydride electrodes [9,10].…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Structure–properties relationship in RE3−Mg Ni9H10–13 (RE = La,Pr,Nd) hydrides for energy storage

Yartys

Denys

2015

Journal of Alloys and Compounds

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Ternary RE 3-x Mg x Ni 9 intermetallics are promising battery electrode materials. Studies of the structure-properties relationships in the (La,Pr,Nd) 3-x Mg x Ni 9 H 10-13 hydrides and initial intermetallics revealed the following: a) Increase of magnesium content causes a gradual shrinking of the trigonal unit cells (a, c, V) for all studied RE metals, with the highest solubility range of Mg reached in REMg 2 Ni 9 ; b) Significant lowering of the thermodynamic stability follows an increase in magnesium content from x =1.0 to 1.1-1.2 and a replacement of La by Pr and Nd, with desorption pressures changing in a broad range, from 0.01 bar to 20 bar H 2 ; c) Neutron powder diffraction shows a nearly equal distribution of D atoms within the REMgNi 4 and RENi 5 layers; d) Local hydrogen ordering occurs within the H-sublattice built from MgH 6 octahedra and NiH 4 tetrahedra displaying a directional metal-hydrogen bonding. A partial substitution of Mg for RE allows the electrochemical discharge capacity of the (La,Pr,Nd) 3-x Mg x Ni 9 hydrides to become 25% greater than that of the commercial AB 5 -type electrodes, reaching 400 mAh/g. Synthesis of the materials with a high degree of homogeneity is important and has been achieved by choosing an appropriate synthesis route, content of Mg in the initial mixtures, and time and temperature of the homogenisation process.

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Section: Compounds Re 3−x Mg X Ni 9 (Re=la Pr Nd) With Various Re/msupporting

confidence: 89%

Section: Introductionmentioning

confidence: 99%

Structure–properties relationship in RE3−Mg Ni9H10–13 (RE = La,Pr,Nd) hydrides for energy storage

Yartys

Denys

2015

Journal of Alloys and Compounds

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“…A decrease of the amount of AB 3 -type for the benefit of LaNi 5 phase after DSC is also noticed and it could be attributed to the loss of Mg and Ca elements constituent of the AB 3 . This result is different from the one reported by Hua et al [34] for the La 2 MgNi 9 alloy on which annealing increases the abundance of the AB 3 -type phase.…”

Section: Thermal Treatmentcontrasting

confidence: 99%

Structural and hydrogen storage properties of LaCaMgNi9-type alloy obtained by mechanical alloying

Chebab

Abdellaoui²,

Latroche

et al. 2015

Mater Renew Sustain Energy

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The AB 3 -type LaCaMgNi 9 compound was synthesized using mechanical alloying (MA) starting from elemental La, Ca, Mg, and Ni in the atomic ratio 1:1:1:9. X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) were used to study the phase evolution and formation/kinetic mechanism as a function of milling time (4-30 h). The results show multiphase alloys containing LaCaMgNi 9 as a main phase with trigonal PuNi 3 -type structure (R-3m space group) where Ca atoms occupy preferentially the 3a site, while La and Mg atoms occupy the 6c site with a mean composition CaLa 1.2(2) Mg 0.8(2) Ni 9 . The hydrogenation properties of the alloys were examined by solid-gas reaction at room temperature. The PCI curves showed a plateau pressure of 0.25 bar which corresponds to the AB 3 phase. The hydrogen absorption capacity of the AB 3 phase is equal to 5.6 H/u.f AB3 .

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“…Negative electrodes were fabricated by compacting the alloy powder onto an expanded nickel substrate through a roll mill without any binder. Half-cell measurements were performed using a CTE MCL2 Mini cell testing Annealing has been used to effectively alter the phase components in the AB [38,39], AB 2 [40][41][42][43], AB 3 [44][45][46][47], A 2 B 7 [48][49][50][51], A 5 B 19 [52], AB 5 [53][54][55], A 8 B 21 [56,57], and body-centered-cubic (bcc) [58] MH alloys. According to first-principle calculations on superlattice MH alloy systems, the preferable phase abundance can be influenced by the starting composition and annealing condition [59,60].…”

Section: Methodsmentioning

confidence: 99%

Comparison among Constituent Phases in Superlattice Metal Hydride Alloys for Battery Applications

Kim

Ouchi²,

Nei³

et al. 2017

Batteries

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Abstract:The effects of seven constituent phases-CeNi 3 , NdNi 3 , Nd 2 Ni 7 , Pr 2 Ni 7 , Sm 5 Ni 19 , Nd 5 Co 19 , and CaCu 5 -on the gaseous phase and electrochemical characteristics of a superlattice metal hydride alloy made by induction melting with a composition of Sm 14 La 5.7 Mg 4.0 Ni 73 Al 3.3 were studied through a series of annealing experiments. With an increase in annealing temperature, the abundance of non-superlattice CaCu 5 phase first decreases and then increases, which is opposite to the phase abundance evolution of Nd 2 Ni 7 -the phase with the best electrochemical performance. The optimal annealing condition for the composition in this study is 920 • C for 5 h. Extensive correlation studies reveal that the A 2 B 7 phase demonstrates higher gaseous phase hydrogen storage and electrochemical discharge capacities and better battery performance in high-rate dischargeability, charge retention, and cycle life. Moreover, the hexagonal stacking structure is found to be more favorable than the rhombohedral structure.

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Annealing effect on phase composition and electrochemical properties of the Co-free La2MgNi9 anode for Ni-metal hydride batteries

Cited by 93 publications

References 40 publications

Structure–properties relationship in RE3−Mg Ni9H10–13 (RE = La,Pr,Nd) hydrides for energy storage

Structure–properties relationship in RE3−Mg Ni9H10–13 (RE = La,Pr,Nd) hydrides for energy storage

Structural and hydrogen storage properties of LaCaMgNi9-type alloy obtained by mechanical alloying

Comparison among Constituent Phases in Superlattice Metal Hydride Alloys for Battery Applications

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