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.

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.

Impacts of Melt Spinning and Mn Replacement on Electrochemical Hydrogen Storage Performances of Nanocrystalline and Amorphous Mg2Ni-Type Alloys

2012 ◽  
Vol 251 ◽  
pp. 323-328
Author(s):  
Yang Huan Zhang ◽  
Ying Cai ◽  
Tai Yang ◽  
Zhong Hui Hou ◽  
Guo Fang Zhang ◽  
...  
Keyword(s):  
Hydrogen Storage ◽  
Melt Spinning ◽  
Amorphous Structure ◽  
High Rate ◽  
Electrochemical Performances ◽  
Electrochemical Characteristics ◽  
Secondary Phases ◽  
Nanocrystalline And Amorphous ◽  
Electrochemical Hydrogen Storage ◽  
Rate Discharge

The Mg2Ni-type alloys with a nanocrystalline and amorphous structure have been confirmed possessing superior electrochemical hydrogen storage kinetics. The melt-spinning technique is used to preparing the nanocrystalline and amorphous Mg2Ni-type alloys with the nominal compositions of Mg20Ni10-xMnx (x = 0, 1, 2, 3, 4). The impacts of the melt spinning and the replacement of Ni by Mn on the structures and the electrochemical performances of the alloys are investigated systematically. The analysis of the structures by XRD and HRTEM reveals that the replacement of Ni by Mn facilitates the glass formation in the Mg2Ni-type alloy, and the amorphization degree of the as-spun alloys increases with the growing of the spinning rate. Furthermore, the replacement renders the formation of secondary phases MnNi and Mg instead of altering the Mg2Ni major phase in the alloys. The measurement of the electrochemical characteristics by an automatic galvanostatic system indicates that the discharge capacity and cycle stability of the alloys dramatically grow with the rising of the spinning rate and the amount of Mn replacement, with which the high rate discharge ability (HRD) of the alloys first augments and then falls.

Impact of Melt Spinning on Electrochemical Hydrogen Storage Characteristics of Mg20Ni9M1 (M=Cu, Co) Alloys

2012 ◽  
Vol 581-582 ◽  
pp. 405-409
Author(s):  
Yang Huan Zhang ◽  
Hong Wei Shang ◽  
Guo Fang Zhang ◽  
Tai Yang ◽  
Zhong Hui Hou ◽  
...  
Keyword(s):  
Hydrogen Storage ◽  
Melt Spinning ◽  
Nanocrystalline Structure ◽  
Amorphous Structure ◽  
High Rate ◽  
Nanocrystalline And Amorphous ◽  
Electrochemical Hydrogen Storage ◽  
Rate Discharge ◽  
High Rate Discharge ◽  
Co Alloys

The melt-spinning technique is used to fabricate the Mg20Ni9M1 (M=Cu, Co) alloys with nanocrystalline and amorphous structure. The microstructures of the as-spun alloys were characterized by XRD and TEM. The electrochemical hydrogen storage properties of the alloys were measured. The results show that the as-spun (M=Cu) alloys hold an entire nanocrystalline structure and small amount of amorphous phase is visible on the grain boundaries of the as-spun (M=Co) alloy. The discharge capacity and high rate discharge ability (HRD) of the alloys visibly grow with the rising of the spinning rate. The action of the melt spinning on the cycle stability of the alloys is associated with substitution element. For M=Cu, the capacity retaining rate (SN) evidently falls with the growing of the spinning rate; whereas for M=Co, it first declines and then augments.

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.

Influence of Substituting La with Zr on Electrochemical Characteristics of As-Spun RE–Mg–Ni-Based A2B7-Type Alloys

2012 ◽  
Vol 562-564 ◽  
pp. 72-76
Author(s):  
Yang Huan Zhang ◽  
Tai Yang ◽  
Hong Wei Shang ◽  
Hui Ping Ren ◽  
Ying Cai ◽  
...  
Keyword(s):  
Hydrogen Storage ◽  
Melt Spinning ◽  
Nanocrystalline Structure ◽  
Amorphous Structure ◽  
High Rate ◽  
Partial Substitution ◽  
Electrochemical Characteristics ◽  
Electrochemical Hydrogen Storage ◽  
Rate Discharge ◽  
The Impact

In order to ameriolate the electrochemical hydrogen storage performances of La–Mg–Ni system A2B7-type electrode alloys, the partial substitution of Zr for La has been performed. The La0.75−xZrxMg0.25Ni3.2Co0.2Al0.1 (x = 0, 0.05, 0.1, 0.15, 0.2) electrode alloys were prepared by melt spinning. The influences of substithting La with Zr on the structures and the electrochemical hydrogen storage characteristics of the alloys were investigated. The structure characterized by XRD and TEM displays that the as-spun alloys have a multiphase structure, composing of two main phases (La, Mg)2Ni7 and LaNi5 as well as a residual phase LaNi2. The as-spun Zr-free alloy displays an entire nanocrystalline structure, while an like amorphous structure is detected in the as-spun alloy substituted by Zr, implying that the substitution of Zr for La facilitates the amorphous formation. The substitution of Zr for La markedly enhances the electrochemical cycle stability of the alloys, whereas the impact generated by such substitution on the high rate discharge ability (HRD) of the alloys is different with the variation of the spinning rate. The HRD of the as-spun (5 m/s) alloys yields the largest value with the change of Zr content, but that of the as-spun (20 m/s) alloys always declines with the growing amount of Zr substitution.

Electrochemical Characteristics of Melt Spun Nanocrystalline and Amorphous Mg20Ni6M4 (M=Co, Cu) Alloys Applied to Ni-MH Battery

2012 ◽  
Vol 248 ◽  
pp. 3-8
Author(s):  
Yang Huan Zhang ◽  
Hong Wei Shang ◽  
Guo Fang Zhang ◽  
Tai Yang ◽  
Zhong Hui Hou ◽  
...  
Keyword(s):  
Melt Spinning ◽  
Positive Impact ◽  
Nanocrystalline Structure ◽  
Amorphous Structure ◽  
High Rate ◽  
Electrochemical Characteristics ◽  
Cu Alloys ◽  
Nanocrystalline And Amorphous ◽  
Electrochemical Hydrogen Storage ◽  
Rate Discharge

The melt-spinning technique was used to synthesize the Mg20Ni6M4 (M=Co, Cu) alloys with nanocrystalline and amorphous structure. The microstructures of the as-spun alloys were characterized by XRD and TEM. The electrochemical hydrogen storage properties of the alloys were measured. The 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. The discharge capacity and high rate discharge ability (HRD) of the alloys notably augment with the rising of the spinning rate. The action of the melt spinning on the cycle stability of the alloys is associated with the substitution element. For the (M=Co) alloy, the melt spinning exerts a dramatically positive impact, whereas for the (M=Cu) alloy, its impact is negative.

Enhanced Hydrogen Storage Kinetics of Melt Spun Nanocrystalline and Amorphous Mg2Ni-Type Alloy by Substituting Ni with Co

2011 ◽  
Vol 399-401 ◽  
pp. 1419-1424
Author(s):  
Yang Huan Zhang ◽  
Guo Fang Zhang ◽  
Xia Li ◽  
Zhong Hui Hou ◽  
Yin Zhang ◽  
...  
Keyword(s):  
Melt Spinning ◽  
Cast Alloy ◽  
Nanocrystalline Structure ◽  
Amorphous Structure ◽  
High Rate ◽  
Desorption Kinetics ◽  
Type Alloy ◽  
Nanocrystalline And Amorphous ◽  
Rate Discharge ◽  
High Rate Discharge

The nanocrystalline and amorphous Mg2Ni1-xCox (x=0, 0.1, 0.2, 0.3, 0.4) alloys were prepared by melt-spinning technique. The structures of the alloys were studied by XRD, SEM and HRTEM. The hydrogen absorption and desorption kinetics and the high rate discharge ability (HRD) of the alloys were measured. The results show that the as-spun Co-free alloy holds a typical nanocrystalline structure, whereas the as-spun alloys containing 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 substitution of Co for Ni evidently improves the hydriding and dehydriding kinetics and the HRD of the alloys. With an increase in the amount of Co substitution from 0 to 0.4, the HRD value rises from 52.9% to 60.3% for the as-cast alloy, and from 65.9% to 76.0% for the as-spun (30 m/s) alloy.

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.

Enhanced Electrochemical Hydrogen Storage Characteristics of Mg2Ni-Type Alloy by Substituting Mg with La

2011 ◽  
Vol 399-401 ◽  
pp. 1461-1466
Author(s):  
Hui Ping Ren ◽  
Bao Wei Li ◽  
Yin Zhang ◽  
Zai Guang Pang ◽  
Zhong Hui Hou ◽  
...  
Keyword(s):  
Melt Spinning ◽  
Amorphous Structure ◽  
High Rate ◽  
Electrochemical Performances ◽  
Type Alloy ◽  
Major Phase ◽  
Nanocrystalline And Amorphous ◽  
Ni Alloy ◽  
Electrochemical Hydrogen Storage ◽  
Cast Alloys

The melt-spinning technique is applied to the preparation of the nanocrystalline and amorphous Mg2Ni-type alloys with nominal compositions of Mg2-xLaxNi (x=0, 0.2, 0.4, 0.6). The as-spun alloy ribbons possessing a continuous length, a thickness of about 30 μm and a width of about 25 mm were prepared. The structures of the as-spun alloy ribbons are characterized by XRD, SEM and TEM. The electrochemical performances of the as-spun alloy ribbons are measured by an automatic galvanostatic system. The results show that no amorphous structure is detected in the as-spun Mg2Ni alloy, whereas the as-spun alloys substituted by La display a nanocrystalline and amorphous structure, confirming that the substitution of La for Mg notably intensifies the amorphous forming ability of the Mg2Ni-type alloy. For La content x≤0.2, the substitution of La for Mg brings to the formation of LaMg3 and La2Mg17 phases without changing the Mg2Ni major phase. But as La content is increased to x≥0.4, such substitution changes the major phase of the alloys to (La, Mg)Ni3+LaMg3. The discharge capacity of the as-cast alloys grows with the increasing amount of La substitution, whereas that of the as-spun alloys yields a maximum value with variation of La content. Furthermore, the substitution of La for Mg remarkably enhances the cycle stability of the as-cast and spun alloys. And the high rate dischargeability (HRD) of the as-cast and spun alloys first mounts up then falls with rising La content.

Improved Physical and Electrochemical Hydrogen Storage Kinetics of the As-Spun Mg2Ni-Type Alloys by Substituting Ni with M (M=Co, Cu)

2012 ◽  
Vol 430-432 ◽  
pp. 423-428
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 ◽  
Hydrogen Desorption ◽  
Amorphous Structure ◽  
High Rate ◽  
Desorption Kinetics ◽  
Hydrogen Storage Kinetics ◽  
Electrochemical Hydrogen Storage ◽  
Kinetics Of

In order to improve the physical and electrochemical hydrogen storage kinetics of the Mg2Ni-type alloys, Ni in the alloy was partially substituted by M (M=Co, Cu). Melt-spinning technology was used for the preparation of the Mg20Ni10-xMx (M=Co, Cu; 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 physical and electrochemical hydrogen storage kinetics of the alloys is measured. The results show that the as-spun (M=Cu) alloys hold an entire nanocrystalline structure, whereas the as-spun (M=Co) alloys exhibit a nanocrystalline and amorphous structure, confirming that the substitution of Co for Ni facilitates the glass formation in the Mg2Ni-type alloy. The substitution of M (M=Co, Cu) for Ni engenders an insignificant effect on the hydrogen absorption kinetics of the alloys, but it markedly ameliorates the hydrogen desorption kinetics of the alloys and the high rate discharge ability. With an increase of the M (M=Co, Cu) content from 0 to 4, the hydrogen desorption ratio ( ) is enhanced form 20.0% to 65.43% for the as-spun (20 m/s) alloy (M=Co), and from 20.0% to 52.88% for the as-spun (20 m/s) alloy (M=Cu).

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