Effects of ion irradiation on hydriding rate of Mm based hydrogen storage alloy

Abe, Hiroshi; Morimoto, Ryo; Satoh, Fumiatsu; Azuma, Y.

doi:10.1016/j.jallcom.2005.04.117

Cited by 11 publications

(3 citation statements)

References 16 publications

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“…They also studied the irradiation effect that various ions have on the initial reaction rate of hydrogen absorption in electrode materials for Ni−H and NiM−H batteries based on rare earth based alloys . MmNi 3.48 Co 0.73 Mn 0.45 Al 0.34 (Mm=La 0.35 Ce 0.65 ), which is applied as the negative electrode of the Ni−H batteries and other hydrogen storage systems, was irradiated with H + , Ar + i K + ions of 350 keV energy, while fluence ranged from 10 14 ion/cm 2 to 10 17 ion/cm 2 . Irradiation with Ar + ions increased the initial hydrogenation rate more than irradiation with H + ions.…”

Section: Experimental Approach To Destabilization Of Hydrogen‐storagementioning

confidence: 93%

“…Ion irradiation method found a significant application in the structural destabilization of materials for solid state hydrogen storage ,. This way it is possible to introduce a well‐defined concentration of defects (vacancies and dislocations) in the surface and subsurface layer of material ,.…”

Section: Experimental Approach To Destabilization Of Hydrogen‐storagementioning

confidence: 99%

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Influence of Defects on the Stability and Hydrogen‐Sorption Behavior of Mg‐Based Hydrides

Novaković

Kurko

et al. 2019

ChemPhysChem

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This review deals with the destabilization methods for improvement of storage properties of metal hydrides. Both theoretical and experimental approaches were used to point out the influence of various types of defects on structure and stability of hydrides. As a case study, Mg, and Ni based hydrides has been investigated. Theoretical studies, mainly carried out within various implementations of DFT, are a powerful tool to study mostly MgH 2 based materials. By providing an insight on metalhydrogen bonding that governs both thermodynamics and hydrogen kinetics, they allow us to describe phenomena to which experimental methods have a limited access or do not have it at all: to follow the hydrogen sorption reaction on a specific metal surface and hydrogen induced phase transformations, to describe structure of phase boundaries or to explain the impact of defects or various additives on MgH 2 stability and hydrogen sorption kinetics. In several cases theoretical calculations reveal themselves as being able to predict new properties of materials, including the ways to modify Mg or MgH 2 that would lead to better characteristics in terms of hydrogen storage. The influence of ion irradiation and mechanical milling with and without additives has been discussed. Ion irradiation is the way to introduce a well-defined concentration of defects (Frankel pairs) at the surface and subsurface layers of a material. Defects at the surface play the main role in sorption reaction since they enhance the dissociation of hydrogen. On the other hand, ball-milling introduce defects through the entire sample volume, refine the structure and thus decrease the path for hydrogen diffusion. Two Severe Plastic Deformation techniques were used to better understand the hydrogenation/dehydrogenation kinetics of Mg-and Mg 2 Nibased alloys: Equal-Angular-Channel-Pressing and Fast-Forging. Successive ECAP passes leads to refinement of the microstructure of AZ31 ingots and to instalment therein of high densities of defects. Depending on mode, number and temperature of ECAP passes, the H-sorption kinetics have been improved satisfactorily without any additive for mass H-storage applications considering the relative speed of the shaping procedure. A qualitative understanding of the kinetic advanced principles has been built. Fast-Forging was used for a "quasiinstantaneous" synthesis of Mg/Mg 2 Ni-based composites. Hydrogenation of the as-received almost bi-phased materials remains rather slow as generally observed elsewhere, whatever are multiple and different techniques used to deliver the composite alloys. However, our preliminary results suggest that a synergic hydrogenation / dehydrogenation process should assist hydrogen transfers from Mg/Mg 2 Ni on one side to MgH 2 / Mg 2 NiH 4 on the other side via the rather stable a-Mg 2 NiH 0.3 , acting as in-situ catalyser.

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Section: Experimental Approach To Destabilization Of Hydrogen‐storagementioning

confidence: 93%

Section: Experimental Approach To Destabilization Of Hydrogen‐storagementioning

confidence: 99%

Influence of Defects on the Stability and Hydrogen‐Sorption Behavior of Mg‐Based Hydrides

Novaković

Kurko

et al. 2019

ChemPhysChem

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“…Foi caracterizado ainda o design das baterias e a massa dos seus eletrodos, uma vez que esses parâmetros também influenciam no desempenho elétrico da bateria (WEN-HUA et al, 1995;DENG et al, 1999;ZHOU et al, 1999;CHEN, 2001;ABEA et al, 2006;WANGA et al, 2005;JIANXIN et al, 2001;LIU et al, 2004).…”

Section: Figura 1 Embalagens Das Baterias Original (Esquerda) E Falsunclassified

Estudo do desempenho elétrico e da composição química de baterias de Ni-HM original e falsificada.

et al. 2010

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ResumoNeste trabalho mostramos que a falsificação de produtos tecnológicos atinge também as baterias recarregáveis de níquel hidreto metálico (Ni-HM). Investigamos o desempenho elétrico e a composição química dos eletrodos de baterias de Ni-HM de formato AAA, originais e falsificadas, comercializadas em Londrina, Norte do Paraná. O desempenho elétrico das baterias foi quantificado medindo-se sua capacidade de carga, sob taxa de 0,2C, e a sua potência elétrica média, nas taxas de 0,2 e 0,8 C. Para as análises da composição química as baterias foram desmontadas em vácuo, e seus eletrodos analisados por Fluorescência de Raios-X por Dispersão em Energia (EDXRF) e Difração de Raios-X (XRD). Observou-se que a capacidade de carga da bateria original foi de 920 mAh contra 155 mAh da falsificada, e as potências médias foram respectivamente 210 mW e 41 mW. A composição química dos catodos das baterias, original e falsificadas, é de hidróxido de níquel (Ni (OH) 2 ). Os anodos, no entanto, são diferentes. Na original encontrou-se o composto LaNi 5 e na falsificada o hidróxido de cádmio (Cd (OH) 2 ). As baterias originais, portanto, exibem 6 vezes mais capacidade de carga, 5 vezes mais potência a 0,2 C e 6 vezes a 0,8 C, e ainda são menos agressivas ao meio ambiente por não conterem cádmio. Palavras-chave: Baterias falsificadas. Níquel hidreto metálico. Cádmio. AbstractWe show in this paper that falsifications on technological products have hit even rechargeable nickel metal hydride batteries (Ni-MH). The electrical performance and the electrode chemical composition were investigated for authentic and falsified AAA Ni-MH batteries, purchased in the Londrina market, Paraná State. Battery charge capacities were measured at 0,2 C discharge rate and average electrical power was measured at 0.2 and 0.8 C discharge rate. To perform chemical composition analysis, the batteries were vacuum dismantled and their electrodes were characterized by Energy Dispersive X-Ray Fluorescence (EDXRF) and X-Ray Diffraction (XRD) techniques. It was observed that the charge capacities for the authentic and falsified batteries were 920 and 154 mAh, respectively. The average electrical powers were 210 mW for authentic and 41 mW for falsified batteries. The cathode chemical

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