LOW-Co HYDROGEN ABSORBING ALLOY

摘要

This invention provides a low-Co hydrogen absorbing alloy that possesses both excellent low-temperature output properties (low-temperature capacitance) and service life properties. The low-Co hydrogen absorbing alloy has a CaCu₅-type crystal structure represented by general formula MmNi_aMn_bAl_cCo_dFe_e wherein Mm represents an La-containing misch metal; 0.2 < d = 0. 5; and 5.025 = a + b + c + d + e = 5.200, and is characterized in that the content of La in the hydrogen absorbing alloy is 13 to 27% by weight, and the lattice volume of the CaCu₅ type crystal structure and the full width at half maximum on (002) plane as determined by X-ray diffraction measurement and the refinement of lattice constant for the crystal lattice of the CaCu₅ type crystal structure are not more than 88.70 × 10⁶ (pm³) and not more than 0.29 (º), respectively.