Gs Yuasa International Ltd.

National Institute of Advanced Industrial Science and Technology

Masaharu Watada

Manabu Kanemoto

Tetsuya Ozaki

Minoru Kuzuhara

Tetsuo Sakai

Tadashi Kakeya

Mitsuhiro Kodama

Seijiro Ochiai

Masaki Miiyamoto

Kaori Nishiyabu

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 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 nickel electrode for an alkaline secondary battery includes an electrically conductive base plate, and an active material particle supported on the conductive base plate and including a complex particle with a surface layer that mainly formed of a high-order cobalt compound whose oxidation number of cobalt is higher than +2 on a surface of a core layer particle that forms a high-order nickel hydroxide whose oxidation number of nickel is higher than +2. Lithium (Li) is contained to be a solid solution in the active material particle from 0.01 to 0.5 wt % of a converted amount as a lithium metal by weight of lithium metal divided by a total weight of the high-order nickel hydroxide, the high-order cobalt compound and the lithium metal.

Nickel electrode for alkaline secondary battery and alkaline secondary battery

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

Masaharu Watada