Development of highly efficient hydrogen storage alloys with mixed-phase microstructures for Ni-MH battery.
| Project/Area Number |
12650701
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Structural/Functional materials
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| Research Institution | Tokyo Metropolitan University |
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Principal Investigator |
KAMASAKI Seiji Tokyo Metropolitan Univ., Graduate School of Eng., Assoc.Prof., 大学院・工学(系)研究科(研究院), 助教授 (60106614)
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| Project Period (FY) |
2000 – 2001
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| Project Status |
Completed (Fiscal Year 2001)
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| Budget Amount *help |
¥2,000,000 (Direct Cost: ¥2,000,000)
Fiscal Year 2001: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 2000: ¥1,400,000 (Direct Cost: ¥1,400,000)
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| Keywords | Hydrogen Storage Alloy / Ni-MH Battery / Mg-Ni Alloy / Mechanical Reforming / Mixed Phase Microstructure / Solid Solution of Carbon / MgNi_3C_x / Nonstoichiometric Composition / MgNi3Cx / 水素素吸蔵合金 / MgNi_3C_x / メカニカルアロイング / 脱水素化特性 / 空孔 |
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| Research Abstract |
Recently, it's expected for the Ni-MH battery to fulfil the role as a driving force of electric and hybrid cars. This project aimed at the enhancement of Mg-Ni alloy which can be expected the 2.5 times capacity of rare earth metal-based alloy electrode in alkaline battery. The dehydriding reaction of Mg-based alloy hydrides proceeds only under a high temperature because of the relatively strong chemical bondings between magnesium and hydrogen with the partial ionic characters. We noticed a knowledge previously obtained on the effct of characteristic improvement by making the composite material of Mg_2Ni and graphite carbon with the mechanical reforming technique, namely the effect of mixed phase microstructure by Mg_2Ni and MgNi_3C.
To begin with, we confirmed that the modifier MgNi_3C_x and MgNi_<3-Y>C_x (X≦1, M =Co, A1) were able to synthesize by mechanical alloying of eutectic alloy MgNi_<3-x>M_xand graphite carbon, and evaluated the dehydriding characteristics of the mixed phase composites electrochemically. In the expectation way, the oxidation potentials of the hydrogen absorbed in the composites electrode shifted to the catholic position.However, the excessive processing lowered the effect. The result of the structure analysis of the composites suggested that a primary cause of this effect origineted for the formation of mixed phase microstructure by the parent phase Mg_2Ni which dissolved C atoms in the lattice and the modifier of nonstoichiometric composition carbide.
We obtained the maximum capacity of about 580 Ah/kg and confirmed the remarkable cycle stabilitiy for the desirable composite electrode through the repeat test of electrochemical hydrogeneration and dehydrogeneration.
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Report
(3 results)
Research Products
(19 results)
