Hydrogen storage properties of amorphous and nanocrystalline (Mg24Ni10Cu2)100-xNdx (x = 0–20) alloys

https://doi.org/10.1016/j.ijhydene.2018.08.040Get rights and content

Highlights

  • Mg-Ni-Cu-Nd alloys with different Nd content were prepared.

  • Experimental alloys were processed at different spinning rates.

  • Increasing Nd content promotes the de-/hydriding kinetics of alloys.

  • Adding Nd improves alloys in electrochemical discharge capacity and cycle stability.

  • Melt spinning promotes the de-/hydriding kinetics of alloys.

Abstract

The as-cast and spun (Mg24Ni10Cu2)100-xNdx (x = 0–20) alloys were prepared in this experiment to study their hydrogen storage performances. The alloys were tested on composition, structure, de-/hydriding kinetics and electrochemical property in many ways including XRD, SEM, TEM, Sieverts apparatus and automatic galvanostatic system. It was found that each as-cast alloy is multi-phased, including Mg2Ni-type major phase and some second phases of Mg6Ni, Nd5Mg41 and NdNi, the proportion of which obviously increases with Nd content rising. After being melt spinning, the structure of no-Nd-added alloy is nanocrystalline, while the Nd-added alloy holds an amorphous and nanocrystalline structure, whose amorphization degree rises significantly with Nd content increasing. The hydrogen storage kinetics of alloys can be improved by the addition of Nd significantly. Besides, adding Nd results in the electrochemical discharge capacity of the as-spun alloy augments at first and declines later as well as cycle stability.

Introduction

Hydrogen is deemed as one of the best fuels among all kinds of energy sources in the world for its convenient transportation, high efficiency, high safety coefficient and non-pollution [1]. For realizing the large-scale utilization of hydrogen, hydrogen storage technology becomes the key factor. For now, metal hydride systems are regarded as a good hydrogen storage method for its characters of high accurate, efficient and safe [2], [3], [4], [5], [6], [7], [8], [9]. Mg2Ni-type metal hydrides have many advantages, including high theoretical electrochemical capacity (about 1000 mAh/g) and gaseous hydrogen storage capacity of 3.6 wt% for Mg2NiH4 [10], [11], for which they are outstanding in the utilization in Ni-MH battery negative electrode and hydrogen fuel cell vehicle (HFCV) [12]. However, to realize the large-scale commercial application of hydrogen storage materials, there are still many obstacles need to be overcome, such as the high dehydriding temperature, tardy de-/hydriding kinetics and weak electrochemical cycle stability [13].

As a matter of fact, the chemical compositions and crystalline structures of hydride electrode materials show a lot of influence on their specific capacity and de-/hydriding kinetics [14]. It has been ascertained that comparing with crystalline Mg2Ni, the amorphous and nanocrystalline Mg and Mg-based alloys have larger hydrogen storage capacity and better de-/hydriding kinetics [2], [15]. Undoubtedly, high energy ball-milling is a common method for getting Mg or Mg-based alloys with an amorphous and nanocrystalline structure [12], [16]. However, the metastable structures generated during milling process are easily to be vanished after multiple electrochemical dis-/charging cycles, which results in the poor cycle stability of milled Mg or Mg-based alloys [17]. It is a great challenge for their large-scale application in batteries. As to melt spinning, it improves the Mg-based alloys not merely in overcoming the deficiencies mentioned above, but also in improving the electrochemical dis-/charging cycle stability [18]. In fact, Huang et al. [19] prepared an amorphous and nanocrystalline as-spun (Mg60Ni25)90Nd10 alloy which has a high discharge capacity of 580 mAh/g. Spassov et al. [20] found the rapid solidified Mg63Ni30Y7 alloy holds a maximal hydrogen storage capacity of about 3.0 wt%.

Form our previous work we found that replacing Ni by M (M = Cu, Co, Mn) or substituting Mg by La will dramatically improve the Mg2Ni-type alloys in both electrochemical and gaseous hydrogen storage properties [21], [22]. Thus, it can be anticipated that combing the addition of Cu and Nd elements with melt spinning process may significantly promote Mg2Ni-type alloys in hydrogen storage performances. For validating this judgment, we prepared the as-cast and spun (Mg24Ni10Cu2)100-xNdx (x = 0–20) alloys and performed a systematical research on the influence of adding Nd and Cu on their structures and electrochemical hydrogen storage performances.

Section snippets

Experimental

For convenience, we take Nd0, Nd5, Nd10, Nd15 and Nd20 to represent the (Mg24Ni10Cu2)100-xNdx (x = 0, 5, 10, 15 and 20) alloys with different Nd contents respectively in this experiment. The purities of the metallic materials of Mg, Ni, Cu, and Nd are at least 99.99%, which were all provided by CISRI Corporation. Under the protection of helium of 0.04 MPa, whose purity is 99.9% supplied by CISRI Corporation, the alloy ingots were prepared in a vacuum induction furnace. Partial alloy ingots were

Phase compositions and microstructures

Fig. 1 shows the XRD curves of the as-cast and spun (20 m/s) (Mg24Ni10Cu2)100-xNdx (x = 0–20) alloys. It can be found from Fig. 1 (a) that adding Nd changes the phase compositions of alloys. Obviously, each as-cast alloy holds a multiphase structure. Before adding Nd, the as-cast Nd0 alloy contains two phases of Mg2Ni (ICDD PDF 35-1225) as main phase and Mg6Ni (ICDD PDF 51-1179) as second phase. After adding Nd, there generate two new second phases of NdNi (ICDD PDF 19-0818) and Nd5Mg41 (ICDD

Conclusions

The as-cast and spun (Mg24Ni10Cu2)100-xNdx (x = 0–20) alloys were prepared in this work. We studied the alloys systematically in hydrogen storage properties and got the following primary conclusions:

  • 1.

    All as-cast alloys are multi-phased including the major phase Mg2Ni and some second phases. After adding Nd element, new phases of Nd5Mg41 and NdNi are generated and their proportions increase markedly with Nd content rising. Adding Nd improves the Mg2Ni-type alloy in glass formation, and increases

Acknowledgements

This work is financially supported by the National Natural Science Foundations of China (51761032 and 51471054) and Natural Science Foundation of Inner Mongolia, China (2015MS0558).

References (33)

  • I.P. Jain

    Hydrogen the fuel for 21st century

    Int J Hydrogen Energy

    (2009)
  • B. Sakintuna et al.

    Metal hydride materials for solid hydrogen storage: a review

    Int J Hydrogen Energy

    (2007)
  • Y.H. Zhang et al.

    Hydrogen storage performance of the as-milled Y-Mg-Ni alloy catalyzed by CeO2

    Int J Hydrogen Energy

    (2018)
  • Y.H. Zhang et al.

    Hydrogen storage properties of nanocrystalline and amorphous Pr-Mg-Ni-based alloys synthesized by mechanical milling

    Int J Hydrogen Energy

    (2017)
  • Y.H. Zhang et al.

    Improvement on hydrogen storage thermodynamics and kinetics of the as-milled SmMg11Ni alloy by adding MoS2

    Int J Hydrogen Energy

    (2017)
  • Z.M. Yuan et al.

    Microstructure and enhanced gaseous hydrogen storage behavior of CoS2-catalyzed Sm5Mg41 alloy

    Renew Energy

    (2018)
  • Z.M. Yuan et al.

    Improvement in the hydrogen storage performance of as-milled Sm-Mg alloys using MoS2 nano-particle catalysts

    RSC Adv

    (2017)
  • Z.M. Yuan et al.

    A comparison study of hydrogen storage properties of as-milled Sm5Mg41 alloy catalyzed by CoS2 and MoS2 nano-particles

    J Mater Sci Technol

    (2018)
  • Z.M. Yuan et al.

    Structure, hydrogen storage kinetics and thermodynamics of Mg-base Sm5Mg41 alloy

    Int J Hydrogen Energy

    (2016)
  • D. Chandra et al.

    Hydriding and structural characteristics of thermally cycled and cold-worked V–0.5 at.%C alloy

    J Alloy Comp

    (2008)
  • L. Schlapbach et al.

    Hydrogen-storage materials for mobile applications

    Nature

    (2001)
  • A. Ebrahimi–Purkani et al.

    Nanocrystalline Mg2Ni-based powders produced by high-energy ball milling and subsequent annealing

    J Alloy Comp

    (2008)
  • G.L. Xia et al.

    Monodisperse magnesium hydride nanoparticles uniformly self-assembled on graphene

    Adv Mater

    (2015)
  • M.V. Simičić et al.

    Hydrogen absorption and electrochemical properties of Mg2Ni-type alloys synthesized by mechanical alloying

    J Power Sources

    (2006)
  • A.L. Eric

    Hydrogen storage measurements in novel Mg-based nanostructured alloys produced via rapid solidification and devitrification

    Int J Hydrogen Energy

    (2011)
  • X.B. Yu et al.

    Recent advances and remaining challenges of nanostructured materials for hydrogen storage applications

    Prog Mater Sci

    (2017)
  • Cited by (9)

    • Nanocrystalline structure and electrochemical hydrogen storage properties of the as-milled Mg–V–Ni–Fe–Zn-based materials

      2023, International Journal of Hydrogen Energy
      Citation Excerpt :

      Furthermore, the addition of Zn can improve the corrosion resistance of AB3-type materials [17]. The influence of Ti replacement has been demonstrated in many kinds of literature [18,19]. However, V substitution for Mg has been rarely reported in the literature.

    • A comparative study on hydrogen storage properties of as-cast and extruded Mg-4.7Y-4.1Nd-0.5Zr alloys

      2022, Journal of Physics and Chemistry of Solids
      Citation Excerpt :

      The catalytic action of rare earth hydrides was also known as the “hydrogen pump” effect [43–46]. In view of previous studies, we know that the addition of rare earth elements, especially Nd and Y, can improve hydrogen sorption properties of Mg-based alloys [39,40,47,48]. However, there are almost no reports about the co-doping effects of Nd and Y on hydrogen storage properties of Mg alloys.

    • Electrochemical hydrogen storage properties of mechanically alloyed Mg<inf>0.8</inf>Ti<inf>0.2-x</inf>Mn<inf>x</inf>Ni (x = 0, 0.025, 0.05, 0.1) type alloys

      2022, International Journal of Hydrogen Energy
      Citation Excerpt :

      It is agreed that the Mg(OH)2 layer formation on the Mg alloy surface inhibits hydrogen diffusion and increases charge transfer resistance by covering the electro-active sites [12,13]. Researchers have tried hard to cope with this hydroxide layer by developing new surfaces [14,15] and composition modifications [16–18], novel synthesis methods [19–21], and composite structures [22,23]. Composition modifications with Ti [24,25], Zr [26], Al [27], B [28], Co [15,29,30], Pd [31], Fe [32] and Cr [33] appear to be the most effective method in the improvement of electrochemical performance.

    • High structural stability and hydrogen storage properties of nano-porous Zr-Al-Ni-Pd glassy alloy produced by electrochemical dealloying

      2021, Journal of Non-Crystalline Solids
      Citation Excerpt :

      Unfortunately, the lack of reasonable dehydrogenation temperature and fast absorption-desorption kinetics is the serious obstacle that restricts their possible applications. To overcome the problems associated with Mg metal and Mg-based alloys for hydrogen storage, a nanocrystalline approach was utilized [18,20–23]. It is known that Ni-based amorphous alloy ribbons prepared by melt spinning exhibit rather high strength, good bending ductility and high corrosion resistance [24–30].

    View all citing articles on Scopus
    View full text