| 摘要 |
PROBLEM TO BE SOLVED: To quicken the initial activation velocity of an electrode by containing a salt of group II elements except for a hydroxide in a Laves phase hydrogen storage alloy having crystal structure mainly comprising C14 type or C15 type in an electrode. SOLUTION: When a Laves phase hydrogen storage alloy comes in contact with an alkaline electrolyte, an insulator layer of a dense oxide or hydroxide of Zr or Ti is formed on the surface of the alloy, and absorbing/releasing of hydrogen is made difficult. By containing a salt of group II elements in the alloy, the insulator layer of the dense oxide or hydroxide of Zr or Ti is broken, the isolation of the hydrogen storage alloy particles in an electrode is prevented, and charge/discharge performance is enhanced. A group II element for forming the salt to be contained is selected from Sc, In, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Ho, and Er. The content of the salt is limited to 15 pts.wt. or less based on 100 pts.wt. hydrogen storage alloy powder, the occupying volume of the salt is limited, and the hydrogen storage alloy is efficiently held in the electrode. |
