Hydrogen storage alloy and alkaline storage battery using hydrogen storage alloy as negative electrode active material

摘要

A hydrogen storage alloy of the present invention includes component A including a rare earth element represented by Ln and magnesium and component B including elements containing at least nickel and aluminum, wherein a primary alloy phase of a hydrogen storage alloy represents an A5B19 type structure; a general formula is represented as Ln1-xMgxNiy-a-bAlaMb (wherein M represents at least one element selected from Co, Mn, and Zn; and 0.1=x=0.2, 3.6=y=3.9, 0.1=a=0.2, and 0=b=0.1); a rare earth element Ln includes maximally two elements containing at least La; and absorption hydrogen equilibrium pressure (Pa) is 0.03-0.17 MPa when the hydrogen amount absorbed in the hydrogen storage alloy (H/M (atomic ratio)) at 40 DEG C. is 0.5.