Preparation of Mg–23.5Ni–10(Cu or La) hydrogen-storage alloys by melt spinning and crystallization heat treatment

2008 ◽  
Vol 33 (1) ◽  
pp. 87-92 ◽  
Author(s):  
M SONG ◽  
C YIM ◽  
S KWON ◽  
J BAE ◽  
S HONG
Keyword(s):  
Heat Treatment ◽  
Hydrogen Storage ◽  
Melt Spinning ◽  
Hydrogen Storage Alloys ◽  
Crystallization Heat

Characteristics Before and After Heat Treatment of Co-Free AB3-Type Fe Substituted Hydrogen Storage Alloys Used for Ni-MH Batteries

2010 ◽  
Vol 129-131 ◽  
pp. 1049-1054 ◽  
Author(s):  
Feng Wu ◽  
Min Yu Zhang ◽  
Dao Bin Mu
Keyword(s):  
Heat Treatment ◽  
Hydrogen Storage ◽  
Discharge Capacity ◽  
Cycle Stability ◽  
Hydrogen Storage Alloys ◽  
Positive Effects ◽  
Fe Content ◽  
Before And After ◽  
Short Time ◽  
Positive Effect

In this paper, a series of hydrogen storage Co-free AB3-type alloys were directly synthesized with vacuum mid-frequency melting method, and melted alloys were treated by low temperature-short time heat annealing. XRD results indicate that the main phase of melted La0.7Mg0.3Ni3-xFex (x=0.0~0.4) alloys are LaMg2Ni9 and LaNi5 phase. After heat treatment, some LaMg2Ni9 phase transferred into LaNi3 phase because of the loss of Mg during the heat proceeding. The content of Fe element affects phase structure of alloys and led to different electrochemical properties. Heat treatment has positive effects on cycle stability of La0.7Mg0.3Ni3-xFex (x=0.0~0.4) alloys but could cause little reduction of discharge capacity of Fe substituted alloy. However, the discharge capacity of La0.7Mg0.3Ni2.8Fe0.2 alloy increased after heat treatment. The EIS results show that heat treatment has positive effect on H transfer within alloy, and Fe content is related to the diffusion coefficient of H atoms within alloys.

Effect of Heat Treatment on Properties of Ti-Mn Based Laves Phase Hydrogen Storage Alloys

2003 ◽  
Vol 801 ◽  
Author(s):  
Jang Lijun ◽  
Tu Hailing ◽  
Chen Yi ◽  
Huang zhuo ◽  
Zhan Feng
Keyword(s):  
Heat Treatment ◽  
Hydrogen Storage ◽  
Cell Volume ◽  
Valence Electron ◽  
Storage Capacity ◽  
Xrd Analysis ◽  
Laves Phase ◽  
Hydrogen Storage Alloys ◽  
Hydrogen Storage Capacity ◽  
Electron Atom

AbstractEffect of heat treatment on the properties and microstructure of non-stoichiometric Ti-Mn based hydrogen storage alloys were investigated. The results were presented that the hydrogen storage capacity was increased and the width of P-C-T Plateau extended, but the slope of plateau increased after heat treatment. Through SEM, EDS and XRD analysis, it was found that the crystal parameters and cell volume was increased, meanwhile the composition homogeneity effectively enhanced and the content of C15 phase decreased after heat treatment. The accretion of slope of plateau would be related to the ratio of valence electron/atom of the alloys.

Gaseous and Electrochemical Hydrogen Storage Performances of Nanocrystalline and Amorphous Mg20-xLaxNi10(x=0-6) Alloys Prepared by Melt-Spinning

2011 ◽  
Vol 393-395 ◽  
pp. 786-791
Author(s):  
Hui Ping Ren ◽  
Bao Wei Li ◽  
Yin Zhang ◽  
Zai Guang Pang ◽  
Zhong Hui Hou ◽  
...  
Keyword(s):  
Hydrogen Storage ◽  
Amorphous Phase ◽  
Melt Spinning ◽  
Absorption Capacity ◽  
Hydrogen Storage Alloys ◽  
Type Alloy ◽  
Glass Forming ◽  
Nanocrystalline And Amorphous ◽  
Electrochemical Hydrogen Storage ◽  
A Current

The nanocrystalline and amorphous Mg2Ni-type Mg20-xLaxNi10 (x = 0, 2, 4, 6) hydrogen storage alloys were prepared by melt-spinning technology. The microstructures and hydrogen storage performances of the alloys were characterized. The results show that no amorphous phase is detected in the as-spun La-free alloy, but the as-spun alloys substituted by La hold a major amorphous phase, confirming that the substitution of La for Mg increases the glass forming ability of the Mg2Ni-type alloy. Melt-spinning remarkably improves the hydrogen storage performances of the alloys. When the spinning rate increases from 0 (As-cast was defined as spinning rate of 0 m/s) to 30 m/s, the hydrogen absorption capacity of the alloy (x = 2) at 200°C and 1.5 MPa in 10 min rises from 1.26 to 2.60 wt%, and its electrochemical discharge capacity grows from 197.2 to 406.5 mAh/g at a current density of 20 mA/g.

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