Cycle durability of Ca–Mg–Ni alloys and factors which cause degradation of hydrogen storage capacity

Experimental and theoretical investigation of the cycle durability against CO and degradation mechanism of the LaNi5 hydrogen storage alloy

“…The absorption-desorption cyclic durability was tested using a Sievert's type apparatus (JSW) [4]. For every absorption-desorption cycle, hydrogen was absorbed under the pressure of 2.0 MPa for 30 min and then desorbed under dynamic vacuum using a rotary vacuum pump.…”

Hydrogenation Properties of Ternary Intermetallic Compounds Mg_2&minus;<i>_x</i>Pr<i>_x</i>Ni₄

“…6,7) The maximum hydrogen content of (Mg 0.67 Ca 0.33 )Ni 2 is 1.4 mass% (H/M = 0.7) under hydrogen pressure of 4 MPa at temperature of 278 K. We have improved plateau flatness and cycle durability of (Mg 0.67 Ca 0.33 )Ni 2 C15-type Laves phase by substituting Y for a part of Ca. 8) Hydrogenation properties of the ternary compounds MgRENi 4 (RE = La, Nd and Gd) have been reported by several groups.…”

Phase Stability, Structural Transition, and Hydrogen Absorption−Desorption Features of the Polymorphic La4MgNi19 Compound

“…As hydrogen storage materials, ternary R−Mg−Ni (R = rare earth metals or Ca) compounds have been studied because their hydrogen storage properties are superior to those of corresponding R−Ni compounds. – These R−Mg−Ni compounds have layered structures with the general formula of m [RMgNi 4 ]· n [RNi 5 ] or R n + m Mg m Ni 5 n +4 m , – in which [RMgNi 4 ] (Laves-type) and [RNi 5 ] (AB 5 -type) subunits stack along the c axis alternatively according to certain combinations. , The numbers, m and n , for [RMgNi 4 ] and [RNi 5 ] subunits are dependent on the composition. Among them, R 2 MgNi 9 , , R 3 MgNi 14 , , and R 4 MgNi 19 are the most interesting. , …”