An investigation of gaseous hydrogen storage characterizations of Mg–Y–Ni–Cu alloys synthesized by melt spinning

In order to improve the gaseous hydrogen storage kinetics of the Mg2Ni-type alloys, Ni in the alloy was partially substituted by M (M=Cu, Co). Melt-spinning technology was used for the preparation of the Mg20Ni10-xMx (M=Cu, Co; 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 results show that the as-spun (M=Cu) alloys hold a typical 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 substitution of M (M=Cu, Co) 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. As the M (M=Cu, Co) content increase from 0 to 4, the hydrogen desorption ratio ( ) is enhanced from 27.7% to 58.9% for the as-spun (30 m/s) alloy (M=Cu), and from 27.7% to 70.2% for the as-spun (30 m/s) alloy (M=Co).

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

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.415-417.1565 ◽

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.

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Electrochemical and Gaseous Hydrogen Storage Capacities of As-Spun Nanocrystalline and Amorphous Mg2Ni0.6M0.4 (M=Cu, Co) Alloys

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.581-582.382 ◽

2012 ◽

Vol 581-582 ◽

pp. 382-386

Author(s):

Zhong Hui Hou ◽

Yin Zhang ◽

Ying Cai ◽

Feng Hu ◽

Guo Fang Zhang ◽

...

Keyword(s):

Hydrogen Storage ◽

Melt Spinning ◽

Nanocrystalline Structure ◽

Hydrogen Desorption ◽

Amorphous Structure ◽

Gaseous Hydrogen ◽

Cu Alloy ◽

Nanocrystalline And Amorphous ◽

Kinetics Of ◽

Co Alloys

The melt spinning technology was used to prepare the Mg2Ni0.6M0.4 (M=Cu, Co) hydrogen storage alloys in order to obtain a nanocrystalline and amorphous structure. The microstructures of the alloys were characterized by XRD, TEM. The effects of the melt spinning on the electrochemical and gaseous hydrogen storage capacities of the alloys were investigated. The results indicate that the as-spun (M=Cu) alloys hold an entire nanocrystalline structure even if a limited spinning rate is applied, while the as-spun (M=Co) alloys display a nanocrystalline and amorphous structure and the amount of the amorphous phase grows evidently with the rising of the spinning rate, suggesting that the substitution of Co for Ni facilitates the glass formation in the Mg2Ni-type alloy. The melt spinning enhances the electrochemical and gaseous hydrogen storage capacities of the alloys dramatically. Simultaneously, it ameliorates the hydriding kinetics of the alloys substantially. As the spinning rate grows from 0 (As-cast was defined as the spinning rate of 0 m/s) to 30 m/s, the discharge capacity increases from 53.3 to 140.4 mAh/g for the (M=Cu) alloy and from 113.3% to 402.5% for the (M=Co) alloy; the gaseous hydrogen desorption capacity ( ) in 100 min augments from 2.29% to 2.87% for the (M=Cu) alloy and from 2.42% to 3.08% for the (M=Co) alloy.

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

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.499.25 ◽

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.

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

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.393-395.587 ◽

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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