Gs Yuasa International Ltd.

National Institute of Advanced Industrial Science and Technology

Tetsuya Ozaki

Manabu Kanemoto

Tadashi Kakeya

Masaharu Watada

Tetsuo Sakai

Minoru Kuzuhara

Yoshiteru Kawabe

Provided is a hydrogen storage alloy which is characterized in that two or more crystal phases having different crystal structures are layered in a c-axis direction of the crystal structures. The hydrogen storage alloy is further characterized in that a difference between a maximum value and a minimum value of a lattice constant a in the crystal structures of the laminated two or more crystal phases is 0.03 &#x212b; or less.

Hydrogen storage alloy, hydrogen storage alloy electrode, secondary battery, and method for producing hydrogen storage alloy

It is an object of the present invention to improve the cycle performance in a nickel-metal hydride battery using a rare earth-Mg&#x2014;Ni type alloy. The present invention provides a nickel-metal hydride battery having a negative electrode including an La&#x2014;Mg&#x2014;Ni based hydrogen absorbing alloy, wherein the hydrogen absorbing alloy has a crystal phase having GdCotype crystal structure and contains calcium.

Nickel-metal hydride battery and method for producing hydrogen storage alloy

The present invention provides a hydrogen absorption alloy, which includes chemical composition represented by the general formula M1M2M3CaMgNiM4wherein 16&#xd7;(d&#x2212;1.870)/(d&#x2212;r)&#x2266;v&#x2266;16&#xd7;(d&#x2212;1.860)/(d&#x2212;r); 1.6&#x2266;w&#x2266;3.2; 4.1&#x2266;&#xd7;&#x2266;5.1; 3.2&#x2266;(y+z)/(t+u+v+w+x)&#x2266;3.4; t +u+v+w+x+y+z=100; M1 is one or more elements selected from La, Pr, and Nd; M2 is one or more elements selected from V, Nb, Ta, Ti, Zr, and Hf; M3 is one or more elements selected from Sm, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu; M4 is one or more elements selected from Co, Mn, Al, Cu, Fe, Cr, and Zn; d is an average atomic radius of the elements selected as M1; and r is an average atomic radius of the elements selected as M3; and an electrode and a secondary battery using the same.

Hydrogen absorption alloy, hydrogen absorption alloy electrode, and secondary battery

The present invention provides a hydrogen absorbing alloy containing a phase of a GdCotype crystal structure, wherein the phase exists at a ratio of 10 weight % or higher in the entire hydrogen absorbing alloy and yttrium is contained at a ratio of 2 mol % or more and 10 mol % or less in the entire hydrogen absorbing alloy.

Hydrogen absorbing alloy, production method thereof, and secondary battery

The present invention provides a hydrogen absorbing alloy containing a phase of a PrCotype crystal structure having a composition defined by a general formula ABC(A denotes one or more element(s) selected from rare earth elements including Y (yttrium); B denotes an Mg element; C denotes one or more element(s) selected from a group consisting of Ni, Co, Mn, and Al; and w denotes a numeral in a range from &#x2212;0.1 to 0.8) and having a composition as a whole defined by a general formula R1R2R3(15.8&#x2266;x&#x2266;17.8, 3.4&#x2266;y&#x2266;5.0, 78.8&#x2266;z&#x2266;79.6, and x+y+z=100; R1 denotes one or more element(s) selected from rare earth elements including Y (yttrium); R2 denotes an Mg element, R3 denotes one or more element(s) selected from a group consisting of Ni, Co, Mn, and Al; the numeral of Mn+Al in the z is 0.5 or higher; and the numeral of Al in the z is 4.1 or lower).

Hydrogen absorbing alloy, hydrogen absorbing alloy electrode, secondary battery, and production method of hydrogen absorbing alloy

A hydrogen storage alloy containing a phase of a chemical composition defined by a general formula ABC: wherein in the general formula ABC, A denotes one or more element(s) selected from rare earth elements; B denotes one or more element(s) selected from a group consisting of Mg, Ca, Sr, and Ba; C denotes one or more element(s) selected from a group consisting of Ni, Co, Mn, Al, Cr, Fe, Cu, Zn, Si, Sn, V, Nb, Ta, Ti, Zr, and Hf; and x denotes a numeral in a range from &#x2212;0.1 to 0.8: and the phase has a crystal structure belonging to a space group of R-3and having a length ratio of the c-axis to the a-axis of the lattice constant in a range of 11.5 to 12.5.

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Kyoto, Japan

Tetsuya Ozaki