کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1280198 | 1497670 | 2007 | 8 صفحه PDF | دانلود رایگان |
In this paper, the effects of substitution of Pr for La on the microstructure and electrochemical properties of La0.7-xPrxMg0.3Ni2.45Co0.75Mn0.1Al0.2La0.7-xPrxMg0.3Ni2.45Co0.75Mn0.1Al0.2(x=0.00–0.30)(x=0.00–0.30) hydrogen storage alloys have been studied systematically. XRD Rietveld analyses showed that all alloys consisted of (La,Mg)Ni3(La,Mg)Ni3 phase and LaNi5LaNi5 phase. With the increase in Pr content, the lattice parameters and cell volumes of the component phases all decreased. The electrochemical studies showed that the maximum discharge capacity decreased from 366 to 346 mAh/g when x increased from 0.00 to 0.30. However, the cycling stability of the alloy electrodes was improved with the increase in Pr content. Moreover, the high rate dischargeability, the exchange current density I0I0, the limiting current density ILIL and the hydrogen diffusion coefficient D of the alloy electrodes all increased first then decreased with increasing x, reaching an extreme when x is 0.15, which indicated that the alloys’ kinetics of hydriding/dehydriding increased first up to x=0.15x=0.15 and then decreased with further increasing x to x=0.30x=0.30.
Journal: International Journal of Hydrogen Energy - Volume 32, Issue 14, September 2007, Pages 2949–2956