• Title/Summary/Keyword: Hydrogen Storage Alloy

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Electrochemical Properties of Laves Phase Zr-V System Hydrogen Absorbing Alloys (Zr-V계 Laves상 수소저장합금의 전기화학적 성질)

  • Park, Chan-kyo;Cho, Tae-hwan
    • Journal of Hydrogen and New Energy
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    • v.8 no.2
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    • pp.51-56
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    • 1997
  • The Zr-based Laves phase, $ZrV_2$ hydrogen storage alloy is not suited for the electrode of Ni-MH battery, because the binding strength of that with hydrogen is too strong although the storage capacity is high. For an application to electrode a part of V in alloys is substituted with Ni to make weaken the binding strength. The electrochemical and thermodynamic properties of Zr-V-Ni system alloys are investigated from the equilibrium potential and studied the possibility for the application to the rechargeable battery electrode.

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A Study on the Hydrogen Supply for Variation in Output from a Metal Hydride Canister (금속수소화물 금속용기로부터 출력변동에 필요한 수소공급에 관한 연구)

  • Jung, Young-Guan;Kim, Se-Woong;Kim, Kyung-Hoon;Choi, Seong-Dae;Jang, Tae-Ik;Hwang, Chul-Min
    • Journal of Hydrogen and New Energy
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    • v.20 no.3
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    • pp.216-223
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    • 2009
  • The relation between temperature and hydrogen desorption on variation in output was investigated for the metal hydride canister. For this study, an AB$_5$ type alloy were chosen as a hydrogen storage material in the metal hydride canister. And application to the single proton exchange membrane fuel cell was evaluated. As the results, the hydrogen desorption was linearly increased as the temperature was risen. In addition, metal hydride canister heating was able to correspond the variation of load as power request in the PEMFC system.

The Properties of the Metal Hydride electrodes prepared by Silicon Sealant (Si-sealant를 이용하여 제조한 금속수소화물 전극의 특성)

  • CHOI, Jeon;PARK, Choong-Nyeon
    • Journal of Hydrogen and New Energy
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    • v.4 no.2
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    • pp.23-28
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    • 1993
  • The $(LM)Ni_{4.5}Co_{0.1}Mn_{0.2}Al_{0.2}$ hydrogen storage alloy powders were conducted 25wt% electroless copper plating in an acidic bath. For the preparation of a hydride electrodes, the copper coated alloy powder was mixed with Si-sealant(organosilicon) and compacted with $6t/cm^2$ at room temperature. The electrode characteristics were examined through electrochemical measurements in a half cell. As a sealant contents increased, the initial discharge capacity of si-sealant bounded electrode was lower and the activation rate in high current density was slower. For extended cycles, however, the electrodes with the Si-sealant were superior in a high rate discharge and useful range of temperature over the sealant-free electrode. In addition, the cycle life increased with increasing the amount of Si-sealant added. It can be suggested from the results that the Si-sealant as a binder could be applied to the preparation of the metal hydride electrode.

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Electrochemical Study of Electrode Material of Ni-MH Battery for HEV and PEMFC Fuel Cell (HEV 및 PEMFC 연료전지용 니켈수소 전지의 전극재료에 대한 전기화학적 평가)

  • Kim, Ho-Sung
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.20 no.2
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    • pp.24-28
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    • 2006
  • Electrochemical hydrogenation/dehydrogenation properties were studied for a single particle of a Mm-based(Mm : misch metal) hydrogen storage alloy($MmNi_{3.55}Co_{0.75}Mn_{0.4}Al_{0.3}$) for the anode of Ni-MH batteries. A carbon fiber microelectrode was manipulated to make electrical contact with an alloy particle, and the cyclic voltammetry and the galvanostatic charge/discharge experiments were performed. A single particle of the alloy showed the discharge capacity of 280[mAh/g], the value being 90[%] of the theoretical capacity. Data were compared with that of the composite film consisting of the alloy particles and a polymer binder, which is more practical form for Ni-MH batteries. Additionally, pulverization of the alloy particles are directly observed. Compared with the conventional composite film electrodes, the single particle measurements using the microelectrode gave more detailed, true information about the hydrogen storage alloy.

Reaction Rate with Hydrogen and Hydrogen-storage Capacity of an 80Mg+14Ni+6TaF5 Alloy Prepared by High-energy Ball Milling in Hydrogen (수소 분위기에서 고 에너지 볼 밀링으로 제조한 80Mg+14Ni+6TaF5합금의 수소와의 반응 속도와 수소 저장 용량)

  • PARK, HYE RYOUNG;SONG, MYOUNG YOUP
    • Journal of Hydrogen and New Energy
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    • v.28 no.2
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    • pp.137-143
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    • 2017
  • In the present study, Ni and $TaF_5$ were chosen as additives to enhance the hydriding and dehydriding rates of Mg. A sample with a composition of 80 wt% Mg + 14 wt% Ni + 6 wt% $TaF_5$ (named $80Mg+14Ni+6TaF_5$) was prepared by high-energy ball milling in hydrogen. Its hydriding and dehydriding properties were then examined. At the fourth cycle, the activated sample absorbed 3.88 wt% H for 2.5 min, 4.74 wt% H for 5 min, and 5.75 wt% H for 60 min at 593 K under 12 bar $H_2$. $80Mg+14Ni+6TaF_5$ had an effective hydrogen-storage capacity (the quantity of hydrogen absorbed for 60 min) of about 5.8 wt%. The sample desorbed 1.42 wt% H for 5 min, 3.42 wt% H for 15 min, and 5.09 wt% H for 60 min at 593 K under 1.0 bar $H_2$. Line scanning results by EDS for $80Mg+14Ni+6TaF_5$ before and after cycling showed that the peaks of Ta and F appeared at different positions, indicating that the $TaF_5$ in $80Mg+14Ni+6TaF_5$ was decomposed.