Hydriding and Dehydriding Kinetics of Nanocrystalline and Amorphous Mg20Ni10-xMx (M=Cu, Mn; x = 0-4) Alloys Prepared by Melt Spinning

2012 ◽  
Vol 534 ◽  
pp. 164-168
Author(s):  
Yang Huan Zhang ◽  
Chen Zhao ◽  
Ying Cai ◽  
Hui Ping Ren ◽  
Bao Wei Li ◽  
...  
Keyword(s):  
Melt Spinning ◽  
Nanocrystalline Structure ◽  
Hydrogen Desorption ◽  
Amorphous Structure ◽  
Partial Substitution ◽  
Desorption Kinetics ◽  
Secondary Phases ◽  
Cu Alloy ◽  
Nanocrystalline And Amorphous ◽  
Kinetics Of

The partial substitution of M (M=Cu, Mn) for Ni has been performed in order to ameliorate the hydriding and dehydriding kinetics of Mg2Ni-type hydrogen storage alloys. The melt spinning technology was used to prepare the Mg20Ni10-xMx (M=Cu, Mn; x=0, 1, 2, 3, 4) alloys. The structures of the as-spun alloys were characterized by XRD and TEM. The hydriding and dehydriding 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=Mn) alloys display a nanocrystalline and amorphous structure, confirming that the substitution of Mn for Ni facilitates the glass formation in the Mg2Ni-type alloy. Furthermore, Mn substitution results in the formation of the secondary phases MnNi and Mg instead of changing the major phase of Mg2Ni. The substitution of M (M=Cu, Mn) for Ni exerts an insignificant effect on the hydriding kinetics, but it ameliorates the hydrogen desorption kinetics of the alloys dramatically. The hydrogen desorption ratio ( ) is enhanced form 20.84% to 52.88% for the (M=Cu) alloy spun at 20 m/s, and from 20.84% to 53.87% for the (M=Mn) alloy spun at 20 m/s by increasing the M (M=Cu, Mn) content from 0 to 4.

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

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.

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

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.

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.

Impact of Substitution of M (M=Mn, Cu) for Ni on Hydriding and Dehydriding Kinetics of as-Spun Nanocrystalline and Amorphous Mg2Ni-Type Alloys

2012 ◽  
Vol 608-609 ◽  
pp. 1347-1350
Author(s):  
Yang Huan Zhang ◽  
Hui Ping Ren ◽  
Bao Wei Li ◽  
Zhong Hui Hou ◽  
Guo Fang Zhang ◽  
...  
Keyword(s):  
Melt Spinning ◽  
Nanocrystalline Structure ◽  
Amorphous Structure ◽  
Secondary Phases ◽  
Type Alloy ◽  
Cu Content ◽  
Cu Alloys ◽  
Nanocrystalline And Amorphous ◽  
Kinetics Of ◽  
Xrd And Tem

The Ni was partially substituted by M (M=Co, Cu) in order to ameliorate the hydriding and dehydriding kinetics of Mg2Ni-type alloy. The melt spinning technology was used to prepare the Mg20Ni10-xMx (M=Mn, Cu; x=0, 1, 2, 3, 4) alloys. The structures of the as-spun alloys were characterized by XRD and TEM. The hydriding and dehydriding kinetics of the alloys were measured by an automatically controlled Sieverts apparatus. The results show that the as-spun (M=Mn) alloys hold a nanocrystalline and amorphous structure, whereas the as-spun (M=Cu) alloys display an entire nanocrystalline structure, indicating that the substitution of Mn for Ni facilitates the glass formation in the Mg2Ni-type alloy. Additionally, Mn substitution incurs the formation of secondary phases MnNi and Mg instead of changing the Mg2Ni major phase. The hydriding kinetics of the as-spun alloys first mounts up and then declines with the rising of M (M= Mn, Cu) content, whereas the substitution of M (M=Mn, Cu) for Ni enhances the dehydriding kinetics of the alloy dramatically.

Preparation and Hydrogen Storage Kinetics of Nanocrystalline and Amorphous Mg2Ni-Type Alloys

2013 ◽  
Vol 275-277 ◽  
pp. 1929-1933
Author(s):  
Yang Huan Zhang ◽  
Chen Zhao ◽  
Haitao Wang ◽  
Tai Yang ◽  
Hong Wei Shang ◽  
...  
Keyword(s):  
Hydrogen Storage ◽  
Hydrogen Absorption ◽  
Melt Spinning ◽  
Hydrogen Desorption ◽  
Amorphous Structure ◽  
Absorption Capacity ◽  
Type Alloy ◽  
Cu Alloy ◽  
Nanocrystalline And Amorphous ◽  
Kinetics Of

In order to obtain a nanocrystalline and amorphous structure in the Mg2Ni-type alloy, the melt spinning technology has been used to prepare the Mg20Ni8M2 (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. As the spinning rate is raised from 0 (As-cast was defined as the spinning rate of 0 m/s) to 30 m/s, the hydrogen absorption saturation ratio ( ), a ratio of the hydrogen absorption capacity in 5 min to the saturated hydrogen absorption capacity, are enhanced from 80.43% to 94.38% for the (M = Co) alloy and from 56.72% to 92.74% for the (M = Cu) alloy. The hydrogen desorption ratio ( ), a ratio of the hydrogen desorption capacity in 20 min to the saturated hydrogen absorption capacity of the alloy, are increased from 24.52% to 51.67% for the (M = Co) alloy and from14.89% to 40.37% for the (M = Cu) alloy. Furthermore, the high rate discharge ability (HRD) and the hydrogen diffusion coefficient (D) of the alloys notably mount up with the growing of the spinning rate.

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).

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

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.

Effects of Substituting Ni with Mn on Structure and Hydrogen Storage Characteristics of as-Spun Mg2Ni-Type Alloys

2013 ◽  
Vol 302 ◽  
pp. 109-114
Author(s):  
Yang Huan Zhang ◽  
Chao Xu ◽  
Cheng Zhao ◽  
Hai Tao Wang ◽  
Tai Yang ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Hydrogen Absorption ◽  
Melt Spinning ◽  
Nanocrystalline Structure ◽  
Absorption Capacity ◽  
Partial Substitution ◽  
Desorption Kinetics ◽  
Nanocrystalline And Amorphous ◽  
Mn Content ◽  
Kinetics Of

A partial substitution of Ni by Mn has been implemented in order to improve the hydriding and dehydriding kinetics of the Mg2Ni-type alloys. The nanocrystalline and amorphous Mg2Ni-type Mg20Ni10-xMnx (x = 0, 1, 2, 3, 4) alloys were synthesized by the melt-spinning technique. The structures of the as-cast and spun alloys were studied by x-ray diffraction (XRD), scanning electron microscope (SEM) and high resolution transmission electron microscope (HRTEM). The hydrogen absorption and desorption kinetics of the alloys were measured by using an automatically controlled Sieverts apparatus. The results show that the as-spun Mn-free alloy holds typical nanocrystalline structure, whereas the as-spun containing Mn alloys display a nanocrystalline and amorphous structure, confirming that the substitution of Mn for Ni facilitates the glass forming of the Mg2Ni-type alloy. The hydrogen absorption capacity of the alloys first increases and then decreases with the rising of Mn content, but the hydrogen desorption capacity of the alloys grows with the increasing of Mn content.

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.

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.

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