Effect of Mo additive on hydrogen absorption of rare-earth based hydrogen storage alloy

Microstructure and composition of rare earth-transition metal-aluminium-magnesium alloys

“…The site occupied by Pu in the PuNi 3 -type structure is probably occupied by Pr, La and Mg. These phases are present alongside the La(Ni,Co) 5 and LaAl(Ni,Co) 4 phases. The doublet situated at 2θ = 36° in Figure 6 (also observed for x = 0.3, 0.5 and 0.7) indicates substitution of La with Pr in the crystalline PuNi 3 -type structure (further refinement is necessary to confirm this).…”

“…XRD spectra showed a shift in the d-spacing with increasing praseodymium content in the cast alloys. XRD analyses helped identify four phases in the La 0.7 Mg 0.3 Al 0.3 Mn 0.4 Co 0.5 Ni 3.8 alloy, namely: La(Ni,Co) 5 , LaAl(Ni,Co) 4 , La 2 (Ni,Co) 7 and AlMn(Ni,Co) 2 . The XRD spectra of the Pr-containing alloys showed the phases La(Ni,Co) 5 and LaAl(Ni,Co) 4 , and also that Pr favored the formation of a phase with PuNi 3 -type structure, where Pu is substituted by Pr, La and Mg. Cobalt, on the other hand, substituted nickel in the structures and yielded phases of the type: Pr(Ni,Co) 5 and Pr(Ni, Co) 3 .…”

“…AA size cells in which the (LaNdPr)Al 0.3 Mn 0. 4 Co 0.8 Ni 3.5 electrode alloy contained about 17 at.% Pr in the MM showed a very long cycle life (1400 cycles) with reasonable capacity (1250 mAh) and also discharged rate capacity (1100 mAh at 5 C) 11 . These batteries also showed higher capacity at low temperatures (1050 mAh when discharged at 1 °C and -18 °C).…”

“…The purpose of alloy modification is to improve electrode performance, i.e., high hydrogen storage capacity, improve kinetics of hydrogen absorption and desorption, increase cycle life, improve corrosion resistance, etc. In the past a small amount of praseodymium was added to these materials, along with mish metal (MM) [1][2][3][4][5][6][7][8][9][10] . Optimization of the Pr content (from 0 to 0.4 at.% in the alloy) with respect to electrochemical properties of MMAl 0.3 Mn 0.3 Co 0.4 Ni 4.0 alloys (MM = LaNdPr) has also been reported 11 .…”

Effects of Mo substitution for Ni on the microstructure and property of V-based hydrogen storage alloys

“…In order to improve the cycle stability of this type of alloy, the investigations of the element substitution and additive [10][11][12] were conducted. Some researchers have studied the influence of Mo additive in AB5-type alloys [13,14], but the research of influence of Mo additive in V -based hydrogen storage alloys is seldom.…”