W.K. Zhang
,
C.A. Ma
,
X.G. Yang
金属学报(英文版)
The crystal structure, phase abundance and the electrochemical properties ofZr(Mn1-xNix)2 (0.40≤x≤0.75) alloys were investigated by means of XRD, Rietveldrefinement method and electrochemical measurements. The alloys are multiphase.C15 Laves phase occurs as a main phase accompanying with C14 phase and other mi-nor phases, indicating that Ni element is C15-stabilized element for ZrMn2 alloy. Thephase abundance and lattice parameters of Laves phase are influenced significantly byNi substitution. The Zr(Mn0.45Ni0.55)2 alloy with the highest amount of C15 phaseexhibits the maximum electrochemical capacity of 242mAh/g. C14 phase occurring inZr-Mn-Ni alloys is beneficial for the electrochemical kinetics of hydride electrodes.
关键词:
hydrogen storage alloy
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null
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null
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null
Q.A. Li
,
H.Q. Mo
,
Y.Z. Huo
,
G. Sang
,
Y.F. Chen
,
M.G. Han
,
Y.G. Chen and M.J. Tu Department of Metal Materials
,
Sichuan University
,
Chengdu 610065
,
China
金属学报(英文版)
In this paper,a simulation model for the temperature field in the solidification process and microstructure distribution is presented. Then, the result of simulation for the final microstructure distribution is compared with experiment using 10-Kg ingot of MlNi3.55Al0.3Mn0.4CO0.75 (Ml: Lanthanum-rich Mischmetal) hydrogen stor- age alloy cast in a mould, which agrees with the experiment well. Finally, in order to obtain the expected as-cast microstructure distribution of 15-Kg ingot of MlNi3.55Al0.3Mn0.4Co0.75 alloy, the size of Cu mould is optimized using the model described. The optimized mould is then made and the alloy is cast in it, the expected as-cast microstructure distribution is obtained.
关键词:
hydrogen storage alloy
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null
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null
,
null
X.Z.Sun
,
null
金属学报(英文版)
The degradation behaviors of the TiV-based multiphase hydrogen storage alloy Ti0.8Zr0.2V3.2Mn0.64Cr0.96Ni1.2 during electrochemical cycling in alkaline electrolyte have been studied by XRD, SEM, EIS and AES measurements. XRD analysis indicates that the alloy consists of a C14-type Laves phase and a V-based solid solution. The lattice parameters of both phases are increased after discharged with cycling, which indicates that more irreversible hydrogen remains not discharged in the alloy. It should be responsible for the decrease of discharge capacity. SEM micrographs show that after 10 electrochemical cycles, a large number of cracks can be observed in the alloy, existing mainly in the V-based solid solution phase. Moreover, after 30 cycles, the alloy particles are obviously pulverized due to the larger expansion and shrinkage of cell volumes during hydrogen absorption and desorption, which induces the fast degradation of the TiV-based hydrogen storage alloys. EIS and AES measurements indicate that some passive oxide film has been formed on the surface of alloy electrode, which has higher charge-transfer resistance, lower hydrogen diffusivity, and less electro-catalytic activity. Therefore it can be concluded that the pulverization and oxidation of the alloy are the main factors responsible for the fast degradation of the TiV-based hydrogen storage alloys.
关键词:
metal hydrides
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null
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null
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null
刘卅
,
贾德民
,
郭建维
材料科学与工艺
为了探索新型聚合物双键加氢催化材料,采用XRD和自制吸氢装置等对贮氢合金MlNi_(5-x)(CoMnAl)_x 的组成、吸放氢性能及其催化加氢活性等进行了研究.MlNi_(5-x)(CoMnAl)_x 的P-C-T曲线表明,合金具有较低的平台压力,稳定性好;对比合金表面处理前后的吸氢动力学曲线发现:MlNi_(5-x)(CoMnAl)_x 吸氢初期速度较快,后期则随时间延长吸氢量缓慢增加,而经过[6M KOH+1%KBH_4]处理或Pd修饰后则可迅速达到吸氢平衡.催化聚合物双键加氢性能研究表明,未处理合金对NBR溶液加氢氢化度为零,经过[6M KOH+1%KBH_4]处理和钯修饰后的合金可对NBR、SBS、NR等聚合物双键加氢,氢化度分别为33.5%、32.3%、31.1%.说明合金表面组成及结构对其吸放氢性能和催化活性均有明显影响.
关键词:
贮氢合金
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MlNi_(5-x)(CoMnAl)_x
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吸氢和放氢
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聚合物双键加氢
张眯
,
胡锐
,
张铁邦
,
张云龙
,
薛祥义
,
寇宏超
,
李金山
稀有金属材料与工程
采用磁控溅射技术在Zr70Fe5.4V24.6(质量分数,％,下同)合金基体上沉积Pd膜.研究磁控溅射沉积Pd膜的生长特性和显微组织及Pd膜对Zr70Fe5.4V24.6合金吸/放氢性能的影响规律.结果发现,在Zr70Fe5.4V24.6合金基体上磁控溅射沉积的Pd膜具有fcc结构并在(111)晶面有明显的择优取向.对镀膜后合金吸/放氢性能的测试结果表明,磁控溅射沉积Pd膜对Zr70Fe5.4V24.6合金的活化性能及吸氢动力学无显著影响.沉积Pd膜后Zr70Fe5.4V24.6合金可逆吸氢量H/A由0.63增至1.20,吸氢平台增长量约为90％.氢化物形成焓绝对值的平均值增大约77％,生成熵的平均值增大约56％,沉积Pd膜后的合金与氢结合所形成的氢化物更稳定.
关键词:
储氢合金
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磁控溅射
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Pd膜
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吸氢动力学
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吸氢量
胡锋
,
张羊换
,
张胤
,
蔡颖
,
侯忠辉
,
张国芳
,
李霞
功能材料
用球磨工艺制备CeMg12＋100%Ni电极合金,研究了球磨工艺对合金结构及电化学性能的影响。结果表明球磨CeMg12＋100%Ni合金具有非晶纳米晶结构,由Mg2Ni相以及Ni相组成,其含量随球磨时间的延长而增加,这在一定程度上改善了合金的电化学放电性能。球磨非晶纳米晶具有较好的结构稳定性,在吸氢后形成的氢化物相仍保持非晶纳米晶尺度,这有利于降低氢化物的热稳定性,改善电化学放电性能。
关键词:
储氢合金
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热力学性能
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非晶纳米晶
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电化学PCT
