کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1613435 | 1005597 | 2013 | 4 صفحه PDF | دانلود رایگان |
The low-temperature (−40 °C) electrochemical performance of Y-, Si-, Fe-, Cu-, and Mo-partially substituted AB2 metal hydride alloys was studied. The surface area and catalytic ability of these alloys were obtained from the double-layer capacitance and the product of the double-layer capacitance and charge-transfer resistance from AC impedance measurement, respectively. With the increase in amount of substitution, the surface areas in these substituted alloys showed different degrees of increase: Y-addition exhibited the largest increase, followed by Si-addition, and then Cu-, Mo-, and Fe-additions. The surface catalytic abilities of Si-containing alloys were the highest and followed by those of Mo-containing alloys. Cu-, Y-, and Fe-additions reduced the surface catalytic ability. The resistance at −40 °C benefited from the incorporations of Si, Mo, and Y, and deteriorated with the incorporations of Cu and Fe. In the best scenario of a single element-substituted AB2 alloy, the resistance at −40 °C is still higher than that from a commercially available AB5 alloy. Since the contributions to the low temperature performance of AB2 alloys from various modifiers are not the same, the combination of several modifiers is possible for further optimization.
► The low-temperature electrochemical properties of a few substituted AB2 MH alloy were compared.
► Addition of Y to AB2 alloy increases the surface reactive area.
► The TiNi and YNi secondary phases improve the high surface area and bulk hydrogen diffusion.
Journal: Journal of Alloys and Compounds - Volume 580, Supplement 1, 15 December 2013, Pages S349–S352