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.

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.

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.

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 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 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.

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.

Enhanced Gaseous Hydrogen Storage Kinetics of Mg2Ni-Type Alloys by Melt Spinning and Substituting Ni with Cu

2011 ◽  
Vol 415-417 ◽  
pp. 1708-1712
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 ◽  
Gaseous Hydrogen ◽  
Desorption Kinetics ◽  
Cu Content ◽  
Cast Alloys ◽  
Kinetics Of

The Mg2Ni-type Mg20Ni10-xCux (x = 0, 1, 2, 3, 4) hydrogen storage alloys were prepared by a melt-spinning technology. 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 all the as-spun alloys hold an entire nanocrystalline structure and are free of amorphous phase. The substitution of Cu for Ni leads to a significant refinement of the grains of the as-cast alloys without changing the major phase Mg2Ni. Both the melt spinning and the substitution of Cu for Ni evidently ameliorate the hydriding and dehydriding kinetics of the alloys. The hydrogen absorption saturation ratio ( ) and the hydrogen desorption ratio ( ) of the Cu2 alloy are enhanced from 56.72 to 92.74% and from 14.89 to 40.37% respectively by rising spinning rate from 0 (as-cast was defined as spinning rate of 0 m/s) to 30 m/s. And those of the as-spun (20 m/s) alloys are increased from 85.99 to 91.22% and from 20.84 to 52.88 respectively by growing Cu content from 0 to 4.

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).

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.

Hydrogen Storage Kinetics of Mg20Ni10-xMx (M=Cu, Co; x=0-4) Alloys Prepared by Melt Spinning

2011 ◽  
Vol 148-149 ◽  
pp. 291-296
Author(s):  
Yang Huan Zhang ◽  
Xiao Gang Liu ◽  
Le Le Chen ◽  
Hui Ping Ren ◽  
Guo Fang Zhang ◽  
...  
Keyword(s):  
Hydrogen Storage ◽  
Hydrogen Absorption ◽  
Melt Spinning ◽  
Nanocrystalline Structure ◽  
Hydrogen Desorption ◽  
Gaseous Hydrogen ◽  
Desorption Kinetics ◽  
Content Increase ◽  
Hydrogen Storage Kinetics ◽  
Kinetics Of

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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