PURPOSE: To inexpensively produce a hydrogen storage alloy excellent in characteristics with good productivity at the time of producing an Nb-contg. Laves-phase C15 type hydrogen storage alloy as the material for the-negative electrode of an Ni-secondary battery by using Fe-Nb as the Nb source.
CONSTITUTION: A hydrogen storage alloy having a Laves-phase C15 type crystal structure expressed Zr29Nb3.2V6.8Ni35.9Mn21.7Fe3.4 (atomic ratio) is produced as follows. A low-carbon ferroniobium contg. about 69% Nb and about 30% Fe is used as the Nb source, melted along with other materials such as Zr, V, Ni and Mn in a melting furnace evacuated to 0.01-0.2Torr in the atmosphere of Ar or He and cooled. The furnace is then evacuated to ≤0.1Torr, and the cooled mixture is crushed in gaseous hydrogen at 4kg/cm2G to produce a hydrogen storage alloy. The alloy is inexpensively produced with higher productivity than the case when metallic Nb is used as the Nb source.
SHIMIZU TAKASUMI
MATSUYAMA MAKOTO
