| 摘要 |
A safe and industrially advantageous production method is disclosed for producing a rare earth-Mg-Ni based hydrogen storage alloy which realizes production of a nickel-hydrogen rechargeable battery having excellent cycle characteristics and a large capacity. The method is for producing a rare earth-Mg-Ni based hydrogen storage alloy including element A, Mg, and element B, wherein element A is composed of at least one element R selected from rare earth elements including Sc and Y, and optionally at least one element selected from Zr, Hf, and Ca, and element B is composed of Ni and optionally at least one element selected from elements other than element A and Mg. The method includes first step of mixing an alloy consisting of elements A and B and Mg metal and/or a Mg-containing alloy having a melting point not higher than the melting point of Mg metal, and second step of heat-treating a mixture obtained from first step for 0.5 to 240 hours at a temperature 5 to 250 °C lower than a melting point of the rare earth-Mg-Ni based hydrogen storage alloy to be obtained. |
