An investigation on hydrogen storage kinetics of nanocrystalline and amorphous Mg2Ni1−xCox (x=0–0.4) alloy prepared by melt spinning

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.

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Enhanced Hydrogen Storage Kinetics of Nanocrystalline and Amorphous Mg2Ni-type Alloy by Melt Spinning

Materials ◽

10.3390/ma4010274 ◽

2011 ◽

Vol 4 (1) ◽

pp. 274-287 ◽

Cited By ~ 8

Author(s):

Yang-Huan Zhang ◽

Bao-Wei Li ◽

Hui-Ping Ren ◽

Xia Li ◽

Yan Qi ◽

...

Keyword(s):

Hydrogen Storage ◽

Melt Spinning ◽

Type Alloy ◽

Hydrogen Storage Kinetics ◽

Nanocrystalline And Amorphous ◽

Kinetics Of

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Hydriding and Dehydriding Kinetics of Nanocrystalline and Amorphous Mg20Ni6M4 (M=Cu, Co) Alloys

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.512-515.1389 ◽

2012 ◽

Vol 512-515 ◽

pp. 1389-1394

Author(s):

Yang Huan Zhang ◽

Guo Fang Zhang ◽

Hong Wei Shang ◽

Zhong Hui Hou ◽

Ying Cai ◽

...

Keyword(s):

Hydrogen Storage ◽

Melt Spinning ◽

Nanocrystalline Structure ◽

Amorphous Structure ◽

Type Alloy ◽

Hydrogen Storage Kinetics ◽

Cu Alloy ◽

Nanocrystalline And Amorphous ◽

Kinetics Of ◽

Co Alloys

It was well known that the Mg2Ni-type alloy with a nanocrystalline/amorphous structure possesses superior hydrogen storage kinetics. In order to obtain a nanocrystalline and amorphous structure, the melt spinning was applied to prepare the Mg2Ni-type Mg20Ni6M4 (M=Cu, Co) hydrogen storage alloys. The microstructures of the as-cast and spun alloys were characterized by XRD, SEM and HRTEM. The gaseous hydriding and dehydriding kinetics of the alloys was measured. The results show that the as-spun (M=Co) alloys display a nanocrystalline and amorphous structure as spinning rate approaches to 20 m/s, while the as-spun (M=Cu) alloys hold an entire nanocrystalline structure whatever spinning rate is, suggesting that the substitution of Co for Ni facilitates the glass formation in the Mg2Ni-type alloy. The melt spinning markedly improves the gaseous hydrogen storage kinetics of the alloys. As the spinning rate grows from 0 (as-cast was defined as the spinning rate of 0 m/s) to 30 m/s, the hydrogen absorption saturation ratio ( ) is enhanced from 57.7% to 91.4% for the (M=Cu) alloy and from 77.1% to 93.5% for the (M=Co) alloy. And hydrogen desorption ratio ( ) is raised from 28.7% to 59.0% for the (M=Cu) alloy and from 54.5% to 70.2% for the (M=Co) alloy, respectively.

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Ameliorated Hydrogen Storage Kinetics of Mg20Ni7M3 (M=Co, Cu) Alloys by Melt Spinning

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.184-185.880 ◽

2012 ◽

Vol 184-185 ◽

pp. 880-885

Author(s):

Yang Huan Zhang ◽

Zhong Hui Hou ◽

Li Cui Chen ◽

Tai Yang ◽

Hong Wei Shang ◽

...

Keyword(s):

Hydrogen Storage ◽

Melt Spinning ◽

Amorphous Structure ◽

Limiting Current ◽

Type Alloy ◽

Hydrogen Storage Kinetics ◽

Cu Alloys ◽

Nanocrystalline And Amorphous ◽

Electrochemical Hydrogen Storage ◽

Kinetics Of

In order to obtain a nanocrystalline and amorphous structure in the Mg2Ni-type alloy, the melt spinning was applied to fabricate the Mg20Ni7M3 (M=Co, Cu) hydrogen storage alloys. The microstructures of the alloys were characterized by XRD, SEM and HRTEM. The effects of the melt spinning on the gaseous and electrochemical hydrogen storage kinetics of the alloys were investigated. The results indicate that the as-spun (M=Co) alloys display a nanocrystalline and amorphous structure as spinning rate grows to 20 m/s, while the as-spun (M=Cu) alloys hold an entire nanocrystalline structure even if a limited spinning rate is applied, suggesting that the substitution of Co for Ni facilitates the glass formation in the Mg2Ni-type alloy. The melt spinning remarkably ameliorates the gaseous hydriding and dehydriding kinetics of the alloys. The hydrogen absorption ratio ( ) and hydrogen desorption ratio ( ) are enhanced from 81.9% to 94.7% and from 34.9% to 57.3% for the (M=Co) alloy, and from 57.2% to 92.8% and from 21.6% to 49.6% for the (M=Cu) alloy by raising spinning rate from 0 (as-cast was defined as the spinning rate of 0 m/s) to 30 m/s. Furthermore, the high rate discharge ability (HRD), the limiting current density (IL) and the hydrogen diffusion coefficient (D) of the alloys notably increase with the growing of the spinning rate.

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Preparation and Hydrogen Storage Kinetics of Nanocrystalline and Amorphous Mg20Ni8M2 (M=Cu, Co) Alloys

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.586.50 ◽

2012 ◽

Vol 586 ◽

pp. 50-57

Author(s):

Yang Huan Zhang ◽

Tai Yang ◽

Hong Wei Shang ◽

Guo Fang Zhang ◽

Xia Li ◽

...

Keyword(s):

Hydrogen Storage ◽

Melt Spinning ◽

Nanocrystalline Structure ◽

Hydrogen Desorption ◽

Amorphous Structure ◽

Saturation Ratio ◽

Cu Alloy ◽

Nanocrystalline And Amorphous ◽

Kinetics Of ◽

Co Alloys

In order to obtain a nanocrystalline and amorphous structure, the Mg20Ni8M2 (M=Cu, Co) hydrogen storage alloys were fabricated by the melt spinning technology. The microstructures of the alloys were characterized by XRD, SEM and HRTEM. The effects of the melt spinning on the hydriding and dehydriding kinetics of the alloys were investigated. The results indicate that the as-spun (M=Cu) alloys hold an entire nanocrystalline structure even if the limited spinning rate is applied, while the as-spun (M=Co) alloys display a nanocrystalline and amorphous structure as the spinning rate grows to 30 m/s, suggesting that the substitution of Co for Ni facilitates the glass formation in the Mg2Ni-type alloy. The melt spinning remarkably improves the gaseous hydriding and dehydriding kinetics of the alloys. As the spinning rate grows from 0 (As-cast was defined as the spinning rate of 0 m/s) to 30 m/s, the hydrogen absorption saturation ratio ( ) is enhanced from 56.72% to 92.74% for the (M=Cu) alloy and from 80.43% to 94.38% for the (M=Co) alloy. The hydrogen desorption ratio ( ) is raised from14.89% to 40.37% for the (M=Cu) alloy and from 24.52% to 51.67% for the (M=Co) alloy.

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