HYDROGEN STORAGE ALLOY AND ELECTRODE FOR NICKEL-HYDROGEN BATTERY USING THE SAME

• Main Authors: HIRAYAMA SHIGEO, INOUE HIDETOSHI, NUMATA KOICHI, SAKAI MINORU, KAGEI SHINYA, OKIFUJI TAKASHI
• Format: Patent
• Language: English
• Published: 14.10.2004
• Edition: 7
• Subjects: ALLOYS; BASIC ELECTRIC ELEMENTS; CHEMISTRY; ELECTRICITY; FERROUS OR NON-FERROUS ALLOYS; METALLURGY; PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSIONOF CHEMICAL INTO ELECTRICAL ENERGY; TREATMENT OF ALLOYS OR NON-FERROUS METALS

PROBLEM TO BE SOLVED: To provide a hydrogen storage alloy which imparts a uniform performance to a battery and shows a high activity at the initial stage, and a nickel-hydrogen secondary battery using the same. SOLUTION: The AB5-type hydrogen storage alloy has a CaCu5crystal structure, a composition represented by the formula: MmNiaMnbAlcCodMe(wherein Mm is a misch metal; M is one chosen from Cu, Ti, V, Cr and Zn; and a-e each represents a mole number against 1 molar Mm and satisfies 4.8≤a+b+c+d≤5.4, 3.5≤a≤4.5, 0.2≤b≤0.7, 0.1≤c≤0.4, 0.1≤d≤0.8, 0≤e≤0.2 and 4.80≤a+b+c+d+s≤5.40), a carbon content of the alloy of ≤300 ppm and an iron content of ≤0.5 wt.%. The hydrogen storage alloy thus obtained shows a high activity at the initial stage and is suitably used as a negative electrode of the nickel secondary battery. COPYRIGHT: (C)2005,JPO&NCIPI