Effect of Pd/Mn Substitution on Characteristics of Amorphous Zr-Ni-Ti-V Alloy Hydride Electrodes

2012 ◽  
Vol 1388 ◽  
Author(s):  
Hiroshi Miyamura ◽  
Yoshihisa Fujita ◽  
Balachandran Jeyadevan
Keyword(s):  
Hydrogen Storage ◽  
Amorphous Alloys ◽  
Melt Spinning ◽  
Wide Distribution ◽  
Elemental Substitution ◽  
Electrochemical Hydrogen Storage ◽  
Amorphous Structures ◽  
Effect Of Pd ◽  
Equilibrium Dissociation ◽  
Dissociation Pressures

ABSTRACTHydrogenation properties of some amorphous Zr-Ni-Ti-V based alloys were investigated. Pressure-composition(P-C) isotherms and hydrogen storage capacities at room temperatures were measured and effects of elemental substitution of the components with Pd or Mn were studied. The alloy electrodes were prepared by using amorphous (Zr-Ni-Ti-V)-(Pd,Mn) alloys prepared by the melt spinning method. The amorphous alloys in the electrode kept their amorphous structures during cycles of charge and discharge. The electrochemical hydrogen storage capacities were strongly affected by the substitution amounts of Pd or Mn. Even a small amount of substitution, changed the equilibrium dissociation pressures of the alloy. In the present study, the rechargeable capacity was optimized up to H/M=0.5 for the alloy electrode with the composition of (Zr45Ni30Ti25)-3at%Pd. The slope in the P-C isotherm suggested that the maximum H/M of the alloy would exceed 1.0 at higher hydrogen pressure than 1.0 MPa, however, the wide distribution of hydrogen site energy in the amorphous hydride resulted in extremely large slope in P-C isotherms, and consequently restricted the rechargeable capacities of the electrodes.

Enhanced Electrochemical Hydrogen Storage Characteristics of the as-Spun Mg2Ni-Type Alloys by Substituting Ni with M (M=Cu, Co)

2012 ◽  
Vol 457-458 ◽  
pp. 572-577
Author(s):  
Yang Huan Zhang ◽  
Bao Wei Li ◽  
Hui Ping Ren ◽  
Zai Guang Pang ◽  
Zhong Hui Hou ◽  
...  
Keyword(s):  
Hydrogen Storage ◽  
Melt Spinning ◽  
Nanocrystalline Structure ◽  
Amorphous Structure ◽  
High Rate ◽  
Electrochemical Performances ◽  
Secondary Phases ◽  
Nanocrystalline And Amorphous ◽  
Electrochemical Hydrogen Storage ◽  
Rate Discharge

Mg2Ni-type Mg20Ni10-xMx (M=Cu, Co; x=0, 1, 2, 3, 4) electrode alloys with nanocrystalline and amorphous structure were synthesized by melt-spinning technique. The microstructures of the as-spun alloys were characterized by XRD, SEM and HRTEM. The electrochemical hydrogen storage properties of the experimental alloys were measured. The obtained results show that the as-spun (M=Cu) alloys hold an entire nanocrystalline structure, whereas the as-spun (M=Co) alloys display a nanocrystalline and amorphous structure, confirming that the substitution of Co for Ni facilitates the glass formation in the Mg2Ni-type alloy. Furthermore, such substitution results in the formation of secondary phases Mg2Cu and MgCo2 instead of changing the major phase of Mg2Ni. The substitution of M (M=Cu, Co) for Ni markedly improves the electrochemical performances of the alloys, involving the discharge capacity and the cycle stability as well as the high rate discharge ability.

Improved the Physical and Electrochemical Hydrogen Storage Kinetics of Mg2Ni-Type Alloys by Substituting Ni with Co and Melt Spinning

2011 ◽  
Vol 415-417 ◽  
pp. 1565-1571
Author(s):  
Zhi Hong Ma ◽  
Bo Li ◽  
Dong Liang Zhao ◽  
Hui Ping Ren ◽  
Guo Fang Zhang ◽  
...  
Keyword(s):  
Hydrogen Storage ◽  
Melt Spinning ◽  
Nanocrystalline Structure ◽  
Secondary Phase ◽  
Amorphous Structure ◽  
Co Substitution ◽  
Hydrogen Storage Kinetics ◽  
Nanocrystalline And Amorphous ◽  
Electrochemical Hydrogen Storage ◽  
Kinetics Of

In this paper, melt-spinning technology was used for preparing Mg20Ni10-xCox (x = 0, 1, 2, 3, 4) hydrogen storage alloys. The influences of both the Co substitution and the melt spinning on the the physical and electrochemical hydrogen storage kinetics of the alloys were investigated. The XRD, SEM and TEM characterization exhibits that the as-spun Co-free alloy holds a typical nanocrystalline structure, whereas the as-spun alloys substituted by Co display a nanocrystalline and amorphous structure, confirming that the substitution of Co for Ni facilitates the glass formation in the Mg2Ni-type alloy. The Co substitution gives rise to forming secondary phase MgCo2 without altering the Mg2Ni major phase of the alloys. The measurement of the physical and electrochemical hydrogen storage kinetics of the alloys shows that both the melt spinning and the substitution of Co for Ni markedly improve the physical hydriding and dehydriding kinetics and the electrochmeical kinetics (HRD) of the alloys.

Structure and electrochemical hydrogen storage behaviors of RE-Mg-Ni-Co-Al-based AB 2 -type alloys prepared by melt spinning

2017 ◽  
Vol 699 ◽  
pp. 378-385 ◽  
Author(s):  
Yanghuan Zhang ◽  
Hongwei Shang ◽  
Yaqin Li ◽  
Zhonghui Hou ◽  
Yan Qi ◽  
...  
Keyword(s):  
Hydrogen Storage ◽  
Melt Spinning ◽  
Electrochemical Hydrogen Storage

Electrochemical Hydrogen Storage Performances of the Nanocrystalline and Amorphous Mg2Ni-Type Alloys

2012 ◽  
Vol 557-559 ◽  
pp. 1169-1173
Author(s):  
Yang Huan Zhang ◽  
Chao Xu ◽  
Tai Yang ◽  
Zhong Hui Hou ◽  
Guo Fang Zhang ◽  
...  
Keyword(s):  
Hydrogen Storage ◽  
Melt Spinning ◽  
Nanocrystalline Structure ◽  
Amorphous Structure ◽  
High Rate ◽  
Electrochemical Performances ◽  
Nanocrystalline And Amorphous ◽  
Electrochemical Hydrogen Storage ◽  
Rate Discharge ◽  
Mn Content

The melt-spinning technique is applied to the preparation of the nanocrystalline and amorphous Mg2Ni-type alloys with nominal compositions of Mg20Ni10-xMnx (x=0, 1, 2, 3, 4). The microstructures of the as-cast and spun alloys were characterized by XRD and HRTEM. The electrochemical performances of the as-spun alloys are measured by an automatic galvanostatic system. The results show that the as-spun Mg20Ni10 alloy displays an entire nanocrystalline structure, whereas the as-spun Mg20Ni6Mn4 alloy exhibits a nanocrystalline and amorphous structure, confirming that the substitution of Mn for Ni facilitates the glass formation in the Mg2Ni-type alloy. And the amorphization degree of the as-spun alloys substituted by Mn increases with the growing of the spinning rate. The substitution of Mn for Ni and the melt spinning ameliorate electrochemical hydrogen storage characteristics of the alloys substantially. The electrochemical discharge capacity and cycle stability of the alloys are considerably enhanced by increasing the amount of Mn substitution and the spinning rate. The high rate discharge ability (HRD) of the alloys first augments and then falls with the growing of the Mn content and the spinning rate.

Improved Physical and Electrochemical Hydrogen Storage Kinetics of the Mg20Ni10-XMx (M=Cu, Co; X=0, 4) Alloys by Melt Spinning

2012 ◽  
Vol 499 ◽  
pp. 25-30
Author(s):  
Yang Huan Zhang ◽  
Li Zhao Guo ◽  
Hong Wei Shang ◽  
Zhong Hui Hou ◽  
Ying Cai ◽  
...  
Keyword(s):  
Hydrogen Storage ◽  
Melt Spinning ◽  
Nanocrystalline Structure ◽  
Amorphous Structure ◽  
High Rate ◽  
Secondary Phases ◽  
Type Alloy ◽  
Hydrogen Storage Kinetics ◽  
Electrochemical Hydrogen Storage ◽  
Kinetics Of

It has come to light that the Mg2Ni-type alloy with a nanocrystalline/amorphous structure possesses superior hydrogen storage kinetics. The Mg2Ni-type Mg20Ni10-xMx (M=Cu, Co; x=0, 4) hydrogen storage alloys were synthesized by a melt-spinning technique. The microstructures of the as-cast and spun alloys were characterized by XRD, SEM and HRTEM. The gaseous and electrochemical hydrogen storage kinetics of the alloys was measured. The results show that whatever spinning rate the as-spun (M=Cu) alloys hold an entire nanocrystalline structure. As spinning rate approaches to 20 m/s, the as-spun (M=Co) alloys display a nanocrystalline and amorphous structure, confirming that the substitution of Co for Ni facilitates the glass formation in the Mg2Ni-type alloy. Furthermore, such substitution results in the formation of secondary phases Mg2Cu and MgCo2 instead of changing the major phase of Mg2Ni. The melt spinning markedly improves the gaseous and electrochemical hydrogen storage kinetics of the alloys. The hydrogen absorption ratio (R5a ), hydrogen desorption ratio (R20d ) and the high rate discharge ability (HRD) notably mount up with the growing of the spinning rate.

Electrochemical hydrogen storage characteristics of La0.75−x M x Mg0.25Ni3.2Co0.2Al0.1 (M = Zr, Pr; x = 0, 0.1) alloys prepared by melt spinning

Rare Metals ◽  
2012 ◽  
Vol 31 (5) ◽  
pp. 457-465 ◽  
Author(s):  
Yanghuan Zhang ◽  
Tai Yang ◽  
Ying Cai ◽  
Zhonghui Hou ◽  
Huiping Ren ◽  
...  
Keyword(s):  
Hydrogen Storage ◽  
Melt Spinning ◽  
Electrochemical Hydrogen Storage ◽  
Storage Characteristics

An Investigation on the Gaseous and Electrochemical Hydrogen Storage Kinetics of As-Spun Nanocrystalline Mg20Ni10-xCOx (x=0-4) Alloys

2011 ◽  
Vol 393-395 ◽  
pp. 587-592
Author(s):  
Bao Wei Li ◽  
Hui Ping Ren ◽  
Zhong Hui Hou ◽  
Xiao Gang Liu ◽  
Le Le Chen ◽  
...  
Keyword(s):  
Hydrogen Storage ◽  
Hydrogen Absorption ◽  
Melt Spinning ◽  
Nanocrystalline Structure ◽  
Hydrogen Desorption ◽  
Amorphous Structure ◽  
Desorption Kinetics ◽  
Hydrogen Storage Kinetics ◽  
Electrochemical Hydrogen Storage ◽  
Kinetics Of

In order to improve the gaseous and electrochemical hydrogen storage kinetics of the Mg2Ni-type alloys, Ni in the alloy was partially substituted by element Co. Melt-spinning technology was used for the preparation of the Mg20Ni10-xCox (x=0, 1, 2, 3, 4) hydrogen storage alloys. The structures of the as-cast and spun alloys are characterized by XRD, SEM and TEM. The gaseous hydrogen absorption and desorption kinetics of the alloys were measured by an automatically controlled Sieverts apparatus. The electrochemical hydrogen storage kinetics of the as-spun alloys is tested by an automatic galvanostatic system. The results show that the as-spun Co-free alloy holds a typical nanocrystalline structure, whereas the as-spun alloys substituted by Co display a nanocrystalline and amorphous structure, confirming that the substitution of Co for Ni facilitates the glass formation in the Mg2Ni-type alloy. Both the melt spinning and the substitution of Co for Ni evidently ameliorate the hydriding and dehydriding kinetics and the HRD of the alloys. With an increase in the spinning rate from 0 (As-cast was defined as spinning rate of 0 m/s) to 30 m/s, the hydrogen absorption saturation ratio ( ) of the Co4 alloy grows from 77.1 to 93.5 wt.%, the hydrogen desorption ratio ( ) from 54.5% to 70.2%, the HRD from 60.3% to 76.0%, respectively.

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