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Qidong Wang - One of the best experts on this subject based on the ideXlab platform.
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advanced Hydrogen Storage Alloys for ni mh rechargeable batteries
Journal of Materials Chemistry, 2011Co-Authors: Yongfeng Liu, Hongge Pan, Mingxia Gao, Qidong WangAbstract:Hydrogen Storage Alloys are of particular interest as a novel group in functional materials owing to their potential and practical applications in Ni/MH rechargeable batteries. This review is devoted to the specific alloy families developed for high-energy and high-power Ni/MH batteries in the last decades, especially for EV, HEV and PHEV applications. The scope of the work encompasses principles of Ni/MH batteries, electrochemical Hydrogen Storage thermodynamics and kinetics, prerequisites for Hydrogen Storage electrode Alloys and recent advances in Hydrogen Storage electrode Alloys. Rare earth AB5-type Alloys, Ti- and Zr-based AB2-type Alloys, Mg-based amorphous/nanocrystalline Alloys, rare earth-Mg–Ni-based Alloys and Ti–V-based Alloys are highlighted. Additionally, the challenges met in developing advanced Hydrogen Storage Alloys for Ni/MH rechargeable batteries are pointed out and some research directions are suggested.
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Hydrogen Storage Alloys for high pressure suprapure Hydrogen compressor
Journal of Alloys and Compounds, 2006Co-Authors: Xinhua Wang, Changpin Chen, Rugan Chen, Yan Zhang, Qidong WangAbstract:Abstract In this work, AB 5 type rare earth-based and AB 2 type TiCr 2 -based Hydrogen Storage Alloys were studied for the purpose of high-pressure Hydrogen compression. A pair of Hydrogen Storage Alloys, Ml 0.55 Mm 0.2 Ca 0.25 Ni 5 (Ml: La-rich mischmetal; Mm: Ce-rich mischmetal) and (Ti 0.97 Zr 0.03 ) 1.1 Cr 1.6 Mn 0.4 , with favorable Hydrogen Storage properties was developed as the Alloys for a double-stage high-pressure metal hydride Hydrogen compressor (MHHC). With the developed alloy pair, we designed and built a MHHC prototype with Hydrogen capacity of 100 L, which could produce high-pressure ultrapure Hydrogen with pressure of 45 MPa and purity of 99.9999% from industrial grade Hydrogen (98% purity) at pressure of around 2 MPa. During the compression procedure, only hot water is used as the heating source. The compression characteristics were studied and the thermal efficiency was calculated.
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investigation of the structural and electrochemical properties of superstoichiometric ti zr v mn cr ni Hydrogen Storage Alloys
Journal of The Electrochemical Society, 2002Co-Authors: Hongge Pan, Mingxia Gao, Yunfeng Zhu, Qidong WangAbstract:In this paper, the structural and electrochemical properties of the superstoichiometric (Ti 0.8 Zr 0.2 )(V 0.533 Mn 0.107 Cr 0.16 Ni 0.2 ) x (x = 2, 3, 4, 5, 6) Hydrogen Storage Alloys have been studied systematically. It is found by X-ray diffraction and energy dispersive spectra analysis that all these Alloys mainly consist of two phases, a C 14 Laves phase with hexagonal structure and a V-based solid solution phase with body-centered cubic structure. The lattice parameters and thus the cell volumes of the two phases all decrease when x is increased. The electrochemical measurements indicate that the maximum discharge capacity, the discharge equilibrium potential, the high rate dischargeability, the cyclic stability, the exchange current density I 0 , and the limiting current density I L of the Alloys all increase with increasing x from 2 to 5. When x reaches 6, the discharge equilibrium potential, the high rate dischargeability, and the cyclic stability are still increasing proportionately, while the maximum discharge capacity, the exchange current density I 0 , and the limiting current density 1 L all decrease. Furthermore, the alloy electrodes are activated with more difficulty for the Alloys with higher stoichiometry x. Consequently, we believe that the superstoichiometry is an effective way to improve the overall electrochemical properties of the Ti-based Laves-phase Hydrogen Storage Alloys used for the negative electrodes of the Ni-MH secondary batteries.
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Hydrogen Storage properties of FeTi1.3+x wt%Mm (x=0.0, 1.5, 3.0, 4.5, 6.0) Hydrogen Storage Alloys
International Journal of Hydrogen Energy, 2000Co-Authors: Jianxin Ma, Hongge Pan, Changpin Chen, Xinhua Wang, Qidong WangAbstract:In this paper, the Hydrogen Storage properties of FeTi1.3+x wt%Mm (x=0.0, 1.5, 3.0, 4.5, 6.0) Hydrogen Storage Alloys, including the activation characteristics, pressure-composition isotherms and Hydrogen Storage capacities, have been investigated systematically. The results indicate that the activation characteristics of an FeTi alloy modified with excess Ti and a small amount of Mm has been improved markedly. The Alloys absorb a noticeable amount of Hydrogen after a short period of incubation time at room temperature without any previous thermal treatment. Hydrogen Storage properties of modified Alloys vary with the content of Mm and the reaction temperature.
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Hydrogen Storage properties of FeTi1.3 + x wt%Mm (x = 0.0, 1.5, 3.0, 4.5, 6.0) Hydrogen Storage Alloys
International Journal of Hydrogen Energy, 2000Co-Authors: Jianxin Ma, Changpin Chen, Xinhua Wang, Qidong WangAbstract:In this paper, the Hydrogen Storage properties of FeTi1.3+x wt%Mm (x=0.0, 1.5, 3.0, 4.5, 6.0) Hydrogen Storage Alloys, including the activation characteristics, pressure-composition isotherms and Hydrogen Storage capacities, have been investigated systematically. The results indicate that the activation characteristics of an FeTi alloy modified with excess Ti and a small amount of Mm has been improved markedly. The Alloys absorb a noticeable amount of Hydrogen after a short period of incubation time at room temperature without any previous thermal treatment. Hydrogen Storage properties of modified Alloys vary with the content of Mm and the reaction temperature.
Hongge Pan - One of the best experts on this subject based on the ideXlab platform.
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advanced Hydrogen Storage Alloys for ni mh rechargeable batteries
Journal of Materials Chemistry, 2011Co-Authors: Yongfeng Liu, Hongge Pan, Mingxia Gao, Qidong WangAbstract:Hydrogen Storage Alloys are of particular interest as a novel group in functional materials owing to their potential and practical applications in Ni/MH rechargeable batteries. This review is devoted to the specific alloy families developed for high-energy and high-power Ni/MH batteries in the last decades, especially for EV, HEV and PHEV applications. The scope of the work encompasses principles of Ni/MH batteries, electrochemical Hydrogen Storage thermodynamics and kinetics, prerequisites for Hydrogen Storage electrode Alloys and recent advances in Hydrogen Storage electrode Alloys. Rare earth AB5-type Alloys, Ti- and Zr-based AB2-type Alloys, Mg-based amorphous/nanocrystalline Alloys, rare earth-Mg–Ni-based Alloys and Ti–V-based Alloys are highlighted. Additionally, the challenges met in developing advanced Hydrogen Storage Alloys for Ni/MH rechargeable batteries are pointed out and some research directions are suggested.
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rare earth mg ni based Hydrogen Storage Alloys as negative electrode materials for ni mh batteries
Journal of Alloys and Compounds, 2011Co-Authors: Yongfeng Liu, Mingxia Gao, Yanhui Cao, Li Huang, Hongge PanAbstract:Abstract This review is devoted to new rare earth–Mg–Ni-based (R–Mg–Ni-based) Hydrogen Storage Alloys that have been developed over the last decade as the most promising next generation negative electrode materials for high energy and high power Ni/MH batteries. Preparation techniques, structural characteristics, gas–solid reactions and electrochemical performances of this system alloy are systematically summarized and discussed. The improvement in electrochemical properties and their degradation mechanisms are covered in detail. Optimized alloy compositions with high discharge capacities, good electrochemical kinetics and reasonable cycle lives are described as well. For their practical applications in Ni/MH batteries, however, it is essential to develop an industrial-scale homogeneous preparation technique, and a low-cost R–Mg–Ni-based electrode alloy (low-Co or Co-free) with high discharge capacity, long cycle life and good kinetics.
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a study on the structural and electrochemical properties of la0 7 xndxmg0 3ni2 45co0 75mn0 1al0 2 x 0 0 3 0 Hydrogen Storage Alloys
Journal of Alloys and Compounds, 2008Co-Authors: Mingxia Gao, Hongge Pan, Yongquan LeiAbstract:Abstract The effects of substitution of Nd for La on the structural and electrochemical properties of the La 0.7− x Nd x Mg 0.3 Ni 2.45 Co 0.75 Mn 0.1 Al 0.2 ( x = 0.0–0.3) Hydrogen Storage Alloys had been studied systematically. X-ray powder diffraction (XRD) investigation showed that all the Alloys were mainly composed of the (La,Mg)Ni 3 phase and the LaNi 5 phase, and the lattice parameters and cell volumes of the component phases gradually decreased with increasing Nd content. The electrochemical studies revealed that the maximum discharge capacity decreased when x increases from 0.0 to 0.3. However, the cycling stability of the alloy electrodes was slightly improved. After 100 charge/discharge cycles, the capacity retention ( C 100 / C max ) of the alloy electrode was increased from 78.2 to 81.3% with x increasing from 0.00 to 0.30. The high rate dischargeability of the alloy electrodes were first increased from 61.8% ( x = 0.00) to 70.1% ( x = 0.10) and then decreased to 53.7% ( x = 0.30) at the discharge current density I d = 1000 mA/g. Meanwhile, the results obtained from the electrochemical impedance spectroscopy, linear polarization, Tafel polarization, and Hydrogen diffusion coefficient measurements indicated that the exchange current density I 0 , the limiting current density I L and the Hydrogen diffusion coefficient D of the alloy electrodes also first increased and then decreased with increasing Nd content, which implies that the electrochemical kinetics of the testing Alloys could be effectively improved by partial substitution of Nd for La. Considering the overall effects of substitution of Nd for La on the La 0.7− x Nd x Mg 0.3 Ni 2.45 Co 0.75 Mn 0.1 Al 0.2 ( x = 0.00–0.30) alloy electrodes, the optimum composition was found to be x = 0.10.
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influences of co substitution and annealing treatment on the structure and electrochemical properties of Hydrogen Storage Alloys la0 7mg0 3ni2 45 xco0 75 xmn0 1al0 2 x 0 00 0 15 0 30
International Journal of Hydrogen Energy, 2007Co-Authors: He Miao, Hongge Pan, Shengcai Zhang, Ni Chen, Mingxia GaoAbstract:Abstract In this paper, the effects of both Co substitution and annealing treatment on the structures and electrochemical properties of La 0.7 Mg 0.3 Ni 2.45 - x Co 0.75 + x Mn 0.1 Al 0.2 ( x = 0.00 , 0.15 , 0.30 ) Hydrogen Storage Alloys have been studied. X-ray diffraction (XRD) analyses show that the main phases of all of the Alloys are ( La , Mg ) Ni 3 phase ( PuNi 3 -type structure) and LaNi 5 phase ( CaCu 5 -type structure). Electrochemical investigations show that increasing Co content and annealing treatment can considerably enhance the cyclic stability of the alloy electrodes. For La 0.7 Mg 0.3 Ni 2.15 Co 1.05 Mn 0.1 Al 0.2 alloy, the value of C 100 / C max was only 65.5% at its as-cast, however, the value reached 80.5% after an annealing treatment of 1173 K × 8 h . The maximum discharge capacity of the alloy electrodes increased by annealing treatment and decreased slightly when Co content increased from x = 0.00 to 0.30 at its as-cast state. But the exchange current density ( I 0 ) , the limiting current density ( I L ) and the diffusion coefficient of Hydrogen ( D ) of the alloy electrodes decreased, leading to a corresponding reduction of the high rate dischargeability (HRD), with increasing Co content and annealing treatment.
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effect of the cerium content on the structural and electrochemical properties of the la0 7 xcexmg0 3ni2 875mn0 1co0 525 x 0 0 5 Hydrogen Storage Alloys
Journal of Alloys and Compounds, 2004Co-Authors: Hongge Pan, Mingxia Gao, Yongfeng Liu, Qinwei Jin, Yongquan LeiAbstract:Abstract In this paper, the effect of the cerium content on the structural and electrochemical properties of the La0.7−xCexMg0.3Ni2.875Mn0.1Co0.525 (x=0–0.5) Hydrogen Storage Alloys has been studied systematically. It is found by XRD Rietveld analysis that all these Alloys mainly consist of two phases: the La(La,Mg)2Ni9 phase with the rhombohedral PuNi3-type structure and the LaNi5 phase with the hexagonal CaCu5-type structure. The abundance of the La(La,Mg)2Ni9 phase increases with increasing cerium content. The P–C isotherms curves show that with increasing Ce content in the Alloys, the plateau pressure of the Hydrogen absorption and desorption increases steeply and the plateau region becomes narrower and steeper. It is found that with increasing Ce content the discharge capacity decreases and the cycling life can be gradually improved. The high rate dischargeability (HRD), the exchange current density I0, and the limiting current density IL of the alloy electrodes increases from x=0 to 0.3 and then decreases with the increase of Ce content.
Xin-lin Wang - One of the best experts on this subject based on the ideXlab platform.
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Effects of substituting Ni with Al on the microstructure and electrochemical performances of the as-cast and quenched La–Mg–Ni-based (PuNi3-type) Hydrogen Storage Alloys
Materials Chemistry and Physics, 2007Co-Authors: Yanghuan Zhang, Hui-ping Ren, Yin Cai, Xin-lin WangAbstract:Abstract In order to improve the cycle stability of La–Mg–Ni system (PuNi3-type) Hydrogen Storage alloy, Ni in the alloy was partially substituted by Al, and La0.7Mg0.3Ni2.55−xCo0.45Alx (x = 0, 0.1, 0.2, 0.3, 0.4) Hydrogen Storage Alloys were prepared by casting and rapid quenching. The effects of substituting Ni with Al on the microstructures and electrochemical performances of the as-cast and quenched Alloys were investigated in detail. The results obtained by XRD show that the as-cast and quenched Alloys have a multiphase structure, including the (La, Mg)Ni3, the LaNi5 and the LaNi2 phases. The substitution of Al for Ni increases the amount of the LaNi2 phase in the as-cast Alloys, but it has an inappreciable influence on the abundance of the LaNi2 phase in the as-quenched alloy. The results obtained by SEM and TEM indicate that the substitution of Al for Ni leads to the grains of the as-quenched Alloys coarsen and restrain an amorphous phase formed in the as-quenched Alloys. The results of the electrochemical measurement indicate that the capacities of the as-cast and quenched Alloys monotonously decrease and their cycle stabilities significantly increase with the increase of Al content. When the amount of substitution Al for Ni increased from 0 to 0.4, the cycle life of the as-cast Alloys increased from 72 to 132 cycles, and that of the as-quenched (20 m s−1) Alloys from 86 to 134 cycles.
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Microstructure and electrochemical performances of La0.7Mg0.3Ni2.55- xCo0.45Alx (x=0-0.4) Hydrogen Storage Alloys prepared by casting and rapid quenching
Journal of Alloys and Compounds, 2005Co-Authors: Hui-ping Ren, Yanghuan Zhang, Xiao-ping Dong, Jiang-yuan Ren, Xin-lin WangAbstract:Abstract In order to improve the cycle stability of La–Mg–Ni system (PuNi 3 -type) Hydrogen Storage alloy, Ni in the alloy was partly substituted by Al, and La 0.7 Mg 0.3 Ni 2.55− x Co 0.45 Al x ( x = 0, 0.1, 0.2, 0.3, 0.4) Hydrogen Storage Alloys were prepared by casting and rapid quenching. The effects of substituting Ni with Al and rapid quenching on the microstructures and electrochemical performances of the as-cast and quenched Alloys were investigated in detail. The results obtained by XRD show that the as-cast and quenched Alloys have a multiphase structure, including the (La, Mg)Ni 3 phase, the LaNi 5 phase and the LaNi 2 phase. The substitution of Al for Ni increases the amount of the LaNi 2 phase in the as-cast Alloys, but it has an inappreciable influence on the abundance of the LaNi 2 phase in the as-quenched alloy. The results obtained by the electrochemical measurement indicate that the capacities of the as-cast and quenched Alloys monotonously decrease and their cycle stabilities significantly increase with the increase of Al content. Rapid quenching leads to the decrease of the capacity and an obvious improvement of the cycle stability of the Alloys.
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Effect of rapid quenching on the microstructures and electrochemical performances of Co-free AB5-type Hydrogen Storage Alloys
International Journal of Hydrogen Energy, 2005Co-Authors: Yanghuan Zhang, Shi-hai Guo, Guo-qing Wang, Xiao-ping Dong, Xin-lin WangAbstract:Abstract In order to compare the effects of the preparation techniques on the electrochemical performances of Co-free AB 5 -type Hydrogen Storage Alloys, the Co-free AB 5 -type La x Mm 1 - x (NiMnSiAlFe) 4.9 ( x = 0 , 0.45 , 0.75 , 1.0 ) Hydrogen Storage Alloys were prepared by casting and rapid quenching. The phase structures and microstructures of the as-cast and quenched Alloys were analyzed by XRD, SEM and TEM. The effects of the rapid quenching on the microstructures and electrochemical performances of the specimen Alloys were investigated in detail. The obtained results show that, when the amount of the La substitution x = 0.75 , the discharge capacity of the as-quenched alloy with quenching rate of 10 m/s is 292 mA h/g with charge-discharge current density of 60 mA/g, the capacity retaining rate ( R h ) is 61.2% after 300 charge-discharge cycles with current density of 300 mA/g. When the amount of the La substitution x = 1 , the discharge capacities of the as-quenched alloy with quenching rate of 10 and 16 m/s are 300 and 292 mA h/g, and the capacity retaining rates ( R h ) are 62.3% and 65.0%, respectively.
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Effect of substituting Co with Fe on the cycle stabilities of the as-cast and quenched AB5-type Hydrogen Storage Alloys
Journal of Power Sources, 2005Co-Authors: Yanghuan Zhang, Shi-hai Guo, Guo-qing Wang, Xiao-ping Dong, Jiang-yuan Ren, Xin-lin WangAbstract:Abstract The rare-earth-based AB 5 -type Mm(NiMnSiAl) 4.3 Co 0.6− x Fe x ( x = 0, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6) Hydrogen Storage Alloys were prepared by casting and rapid quenching. The microstructures of the as-cast and quenched Alloys were analysed by XRD, SEM and TEM, and electrochemical cycle stabilities of the Alloys were measured. The effects of substituting Co with Fe on microstructures and cycle stabilities of the as-cast and quenched Alloys were investigated in detail. The obtained results show that the effects of substituting Co with Fe on the phase structures of the as-cast and quenched Alloys are imperceptible, but its effects on cycle stabilities of the Alloys are notable. Substituting Co with Fe improves slightly the cycle stabilities of the as-cast Alloys, but it can significantly enhance the cycle lives of the as-quenched Alloys, which is mainly attributed to the grain refinement of the Alloys caused by substituting Co with Fe.
Mingxia Gao - One of the best experts on this subject based on the ideXlab platform.
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advanced Hydrogen Storage Alloys for ni mh rechargeable batteries
Journal of Materials Chemistry, 2011Co-Authors: Yongfeng Liu, Hongge Pan, Mingxia Gao, Qidong WangAbstract:Hydrogen Storage Alloys are of particular interest as a novel group in functional materials owing to their potential and practical applications in Ni/MH rechargeable batteries. This review is devoted to the specific alloy families developed for high-energy and high-power Ni/MH batteries in the last decades, especially for EV, HEV and PHEV applications. The scope of the work encompasses principles of Ni/MH batteries, electrochemical Hydrogen Storage thermodynamics and kinetics, prerequisites for Hydrogen Storage electrode Alloys and recent advances in Hydrogen Storage electrode Alloys. Rare earth AB5-type Alloys, Ti- and Zr-based AB2-type Alloys, Mg-based amorphous/nanocrystalline Alloys, rare earth-Mg–Ni-based Alloys and Ti–V-based Alloys are highlighted. Additionally, the challenges met in developing advanced Hydrogen Storage Alloys for Ni/MH rechargeable batteries are pointed out and some research directions are suggested.
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rare earth mg ni based Hydrogen Storage Alloys as negative electrode materials for ni mh batteries
Journal of Alloys and Compounds, 2011Co-Authors: Yongfeng Liu, Mingxia Gao, Yanhui Cao, Li Huang, Hongge PanAbstract:Abstract This review is devoted to new rare earth–Mg–Ni-based (R–Mg–Ni-based) Hydrogen Storage Alloys that have been developed over the last decade as the most promising next generation negative electrode materials for high energy and high power Ni/MH batteries. Preparation techniques, structural characteristics, gas–solid reactions and electrochemical performances of this system alloy are systematically summarized and discussed. The improvement in electrochemical properties and their degradation mechanisms are covered in detail. Optimized alloy compositions with high discharge capacities, good electrochemical kinetics and reasonable cycle lives are described as well. For their practical applications in Ni/MH batteries, however, it is essential to develop an industrial-scale homogeneous preparation technique, and a low-cost R–Mg–Ni-based electrode alloy (low-Co or Co-free) with high discharge capacity, long cycle life and good kinetics.
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a study on the structural and electrochemical properties of la0 7 xndxmg0 3ni2 45co0 75mn0 1al0 2 x 0 0 3 0 Hydrogen Storage Alloys
Journal of Alloys and Compounds, 2008Co-Authors: Mingxia Gao, Hongge Pan, Yongquan LeiAbstract:Abstract The effects of substitution of Nd for La on the structural and electrochemical properties of the La 0.7− x Nd x Mg 0.3 Ni 2.45 Co 0.75 Mn 0.1 Al 0.2 ( x = 0.0–0.3) Hydrogen Storage Alloys had been studied systematically. X-ray powder diffraction (XRD) investigation showed that all the Alloys were mainly composed of the (La,Mg)Ni 3 phase and the LaNi 5 phase, and the lattice parameters and cell volumes of the component phases gradually decreased with increasing Nd content. The electrochemical studies revealed that the maximum discharge capacity decreased when x increases from 0.0 to 0.3. However, the cycling stability of the alloy electrodes was slightly improved. After 100 charge/discharge cycles, the capacity retention ( C 100 / C max ) of the alloy electrode was increased from 78.2 to 81.3% with x increasing from 0.00 to 0.30. The high rate dischargeability of the alloy electrodes were first increased from 61.8% ( x = 0.00) to 70.1% ( x = 0.10) and then decreased to 53.7% ( x = 0.30) at the discharge current density I d = 1000 mA/g. Meanwhile, the results obtained from the electrochemical impedance spectroscopy, linear polarization, Tafel polarization, and Hydrogen diffusion coefficient measurements indicated that the exchange current density I 0 , the limiting current density I L and the Hydrogen diffusion coefficient D of the alloy electrodes also first increased and then decreased with increasing Nd content, which implies that the electrochemical kinetics of the testing Alloys could be effectively improved by partial substitution of Nd for La. Considering the overall effects of substitution of Nd for La on the La 0.7− x Nd x Mg 0.3 Ni 2.45 Co 0.75 Mn 0.1 Al 0.2 ( x = 0.00–0.30) alloy electrodes, the optimum composition was found to be x = 0.10.
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influences of co substitution and annealing treatment on the structure and electrochemical properties of Hydrogen Storage Alloys la0 7mg0 3ni2 45 xco0 75 xmn0 1al0 2 x 0 00 0 15 0 30
International Journal of Hydrogen Energy, 2007Co-Authors: He Miao, Hongge Pan, Shengcai Zhang, Ni Chen, Mingxia GaoAbstract:Abstract In this paper, the effects of both Co substitution and annealing treatment on the structures and electrochemical properties of La 0.7 Mg 0.3 Ni 2.45 - x Co 0.75 + x Mn 0.1 Al 0.2 ( x = 0.00 , 0.15 , 0.30 ) Hydrogen Storage Alloys have been studied. X-ray diffraction (XRD) analyses show that the main phases of all of the Alloys are ( La , Mg ) Ni 3 phase ( PuNi 3 -type structure) and LaNi 5 phase ( CaCu 5 -type structure). Electrochemical investigations show that increasing Co content and annealing treatment can considerably enhance the cyclic stability of the alloy electrodes. For La 0.7 Mg 0.3 Ni 2.15 Co 1.05 Mn 0.1 Al 0.2 alloy, the value of C 100 / C max was only 65.5% at its as-cast, however, the value reached 80.5% after an annealing treatment of 1173 K × 8 h . The maximum discharge capacity of the alloy electrodes increased by annealing treatment and decreased slightly when Co content increased from x = 0.00 to 0.30 at its as-cast state. But the exchange current density ( I 0 ) , the limiting current density ( I L ) and the diffusion coefficient of Hydrogen ( D ) of the alloy electrodes decreased, leading to a corresponding reduction of the high rate dischargeability (HRD), with increasing Co content and annealing treatment.
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effect of the cerium content on the structural and electrochemical properties of the la0 7 xcexmg0 3ni2 875mn0 1co0 525 x 0 0 5 Hydrogen Storage Alloys
Journal of Alloys and Compounds, 2004Co-Authors: Hongge Pan, Mingxia Gao, Yongfeng Liu, Qinwei Jin, Yongquan LeiAbstract:Abstract In this paper, the effect of the cerium content on the structural and electrochemical properties of the La0.7−xCexMg0.3Ni2.875Mn0.1Co0.525 (x=0–0.5) Hydrogen Storage Alloys has been studied systematically. It is found by XRD Rietveld analysis that all these Alloys mainly consist of two phases: the La(La,Mg)2Ni9 phase with the rhombohedral PuNi3-type structure and the LaNi5 phase with the hexagonal CaCu5-type structure. The abundance of the La(La,Mg)2Ni9 phase increases with increasing cerium content. The P–C isotherms curves show that with increasing Ce content in the Alloys, the plateau pressure of the Hydrogen absorption and desorption increases steeply and the plateau region becomes narrower and steeper. It is found that with increasing Ce content the discharge capacity decreases and the cycling life can be gradually improved. The high rate dischargeability (HRD), the exchange current density I0, and the limiting current density IL of the alloy electrodes increases from x=0 to 0.3 and then decreases with the increase of Ce content.
Yongfeng Liu - One of the best experts on this subject based on the ideXlab platform.
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advanced Hydrogen Storage Alloys for ni mh rechargeable batteries
Journal of Materials Chemistry, 2011Co-Authors: Yongfeng Liu, Hongge Pan, Mingxia Gao, Qidong WangAbstract:Hydrogen Storage Alloys are of particular interest as a novel group in functional materials owing to their potential and practical applications in Ni/MH rechargeable batteries. This review is devoted to the specific alloy families developed for high-energy and high-power Ni/MH batteries in the last decades, especially for EV, HEV and PHEV applications. The scope of the work encompasses principles of Ni/MH batteries, electrochemical Hydrogen Storage thermodynamics and kinetics, prerequisites for Hydrogen Storage electrode Alloys and recent advances in Hydrogen Storage electrode Alloys. Rare earth AB5-type Alloys, Ti- and Zr-based AB2-type Alloys, Mg-based amorphous/nanocrystalline Alloys, rare earth-Mg–Ni-based Alloys and Ti–V-based Alloys are highlighted. Additionally, the challenges met in developing advanced Hydrogen Storage Alloys for Ni/MH rechargeable batteries are pointed out and some research directions are suggested.
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rare earth mg ni based Hydrogen Storage Alloys as negative electrode materials for ni mh batteries
Journal of Alloys and Compounds, 2011Co-Authors: Yongfeng Liu, Mingxia Gao, Yanhui Cao, Li Huang, Hongge PanAbstract:Abstract This review is devoted to new rare earth–Mg–Ni-based (R–Mg–Ni-based) Hydrogen Storage Alloys that have been developed over the last decade as the most promising next generation negative electrode materials for high energy and high power Ni/MH batteries. Preparation techniques, structural characteristics, gas–solid reactions and electrochemical performances of this system alloy are systematically summarized and discussed. The improvement in electrochemical properties and their degradation mechanisms are covered in detail. Optimized alloy compositions with high discharge capacities, good electrochemical kinetics and reasonable cycle lives are described as well. For their practical applications in Ni/MH batteries, however, it is essential to develop an industrial-scale homogeneous preparation technique, and a low-cost R–Mg–Ni-based electrode alloy (low-Co or Co-free) with high discharge capacity, long cycle life and good kinetics.
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effect of the cerium content on the structural and electrochemical properties of the la0 7 xcexmg0 3ni2 875mn0 1co0 525 x 0 0 5 Hydrogen Storage Alloys
Journal of Alloys and Compounds, 2004Co-Authors: Hongge Pan, Mingxia Gao, Yongfeng Liu, Qinwei Jin, Yongquan LeiAbstract:Abstract In this paper, the effect of the cerium content on the structural and electrochemical properties of the La0.7−xCexMg0.3Ni2.875Mn0.1Co0.525 (x=0–0.5) Hydrogen Storage Alloys has been studied systematically. It is found by XRD Rietveld analysis that all these Alloys mainly consist of two phases: the La(La,Mg)2Ni9 phase with the rhombohedral PuNi3-type structure and the LaNi5 phase with the hexagonal CaCu5-type structure. The abundance of the La(La,Mg)2Ni9 phase increases with increasing cerium content. The P–C isotherms curves show that with increasing Ce content in the Alloys, the plateau pressure of the Hydrogen absorption and desorption increases steeply and the plateau region becomes narrower and steeper. It is found that with increasing Ce content the discharge capacity decreases and the cycling life can be gradually improved. The high rate dischargeability (HRD), the exchange current density I0, and the limiting current density IL of the alloy electrodes increases from x=0 to 0.3 and then decreases with the increase of Ce content.
