烧结法和熔炼法Ti_3Ni_2储氢合金的电化学性能

Electrochemical Properties of the Sintered and the Melted Ti_3Ni_2 Hydrogen Storage Alloys

对比研究了烧结法和熔炼法制备的Ti3Ni2合金的储氢性能。结果显示,烧结合金具有多孔特性,有利于提高合金的电化学储氢性能。烧结合金的最大放电容量Cmax为305mAh/g,其值远高于熔炼合金的Cmax(242mAh/g)。另外,烧结合金在电化学动力学方面也优于熔炼合金,这主要是由于采用烧结法可以改善氢在Ti3Ni2合金中的扩散,从而使氢的扩散系数(D)从7.16×10-10cm2/s(熔炼合金)提高到3.2×10-9cm2/s(烧结合金)。

The hydrogen storage properties of the Ti3Ni2 alloys prepared by the sintering process and the melting process, respectively were studied. The results show that the sintered alloy has many micro voids which are beneficial to improve the electrochemical hydrogen storage capacity. The sintered alloy has the maximum discharge capacity Cmax of 305 mAh/g, which is much larger than that of the melt alloy （242 mAh/g）. Furthermore, electrochemical kinetic properties of the sintered alloy are also better than those of the melted alloy, because the sintering process can improve the diffusion of hydrogen in the Ti3Ni2 alloy. Therefore, the hydrogen diffusion coefficient D is enhanced from 7.16×10^-10 cm^2/s of the melted alloy to 3.2 × 10^-9 cm^2/s of the sintered alloy.