DEGRADATION BEHAVIORS OF NEW TYPE TiV-BASED HYDROGEN STORAGE ELECTRODE ALLOYS  

作　　者：X.Z. Sun Y. F. Zhu Y. Lin R. Li M.X. Gao H. G. Pan 

机构地区：[1]Department of Materials Science and Engineering, Zhejiang University, Hangzhou310027, China

出　　处：《Acta Metallurgica Sinica(English Letters)》2006年第1期68-74,共7页金属学报（英文版）

基　　金：the National Natural Science Foundation of China（No. 50271063 and No. 50471040）.

摘　　要：The degradation behaviors of the TiV-based multiphase hydrogen storage alloy Ti0.8Zr0.2V3.2Mn0.64 Cr0.96Ni1.2 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 shold 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-hased hydrogen storage alloys.基于 TiV 的多相的氢存储合金 Ti <SUB>0.8</SUB 的降级行为 > Zr <SUB>0.2</SUB > V <SUB>3.2</SUB > Mn <SUB>0.64</SUB>-Cr<SUB>0.96</SUB > Ni <SUB>1.2</SUB> 被 XRD， SEM， EIS 和 AES 在在碱的电解质的电气化学的骑车期间学习了大小。XRD 分析显示合金由洗分阶段执行的 C14 类型和一个基于 V 的稳固的答案组成。在与骑车排出以后，两个阶段的格子参数被增加，它显示更不可逆的氢仍然保持没在合金排出。它应该为分泌物能力的减少负责。SEM 显微图证明在 10 个电气化学的周期以后，很多裂缝能在合金被观察，主要在基于 V 的稳固的答案阶段存在。而且在 30 个周期以后，合金粒子显然在氢吸收和解吸附作用期间由于房间体积的更大的扩大和收缩被研磨，它导致基于 TiV 的氢存储合金的快降级。EIS 和 AES 大小显示某被动氧化物电影在合金电极的表面上被形成了，它有更高的费用转移抵抗，更低的氢扩散性，和不太电镀物品催化的活动。因此，合金的弄成粉和氧化是为基于 TiV 的氢存储合金的快降级负责的主要因素，这能被结束。

关 键 词：metal hydrides hydrogen storage alloy PULVERIZATION DEGRADATION 

分 类 号：TG139.7[一般工业技术—材料科学与工程]