Kabushiki Kaisha Toshiba

Takamichi Inaba

Shusuke Inada

Hideki Yoshida

Masaaki Yamamoto

Isao Sakai

Takao Sawa

Motoya Kanda

Hirotaka Hayashida

Hiroshi Kitayama

Tatsuoki Kono

Fumiyuki Kawashima

Tatsuoki Kohno

Shirou Takeno

Noriaki Yagi

Hiroyuki Hasebe

Yoshiyuki Isozaki

Hiromichi Horie

Hiromi Shizu

Yoshiko Kanazawa

Masami Okamura

Tomohisa Arai

Keisuke Hashimoto

Yumiko Takahashi

Shiro Takeno

Toshiya Sakamoto

Noriaki Sato

The present invention provides a hydrogen absorbing alloy containing as a principal phase at least one phase selected from the group consisting of a second phase having a rhombohedral crystal structure and a first phase having a crystal structure of a hexagonal system excluding a phase having a CaCutype structure, wherein a content of a phase having a crystal structure of ABtype is not higher than 10% by volume including 0% by volume and the hydrogen absorbing alloy has a composition represented by general formula (1) given below:RMgTNiM1M2Mn&#x2003;&#x2003;(1).

Hydrogen absorbing alloy and secondary battery

The present invention provides a hydrogen absorbing alloy containing as a principal phase at least one phase selected from the group consisting of a second phase having a rhombohedral crystal structure and a first phase having a crystal structure of a hexagonal system excluding a phase having a CaCutype structure, wherein a content of a phase having a crystal structure of ABtype is not higher than 10% by volume including 0% by volume and the hydrogen absorbing alloy has a composition represented by general formula (1) given below:MgTNiM1M2Mn.&#x2003;&#x2003;(1)

The present invention provides a hydrogen absorbing alloy containing as a principal phase at least one phase selected from the group consisting of a second phase having a rhombohedral crystal structure and a first phase having a crystal structure of a hexagonal system excluding a phase having a CaCutype structure, wherein a content of a phase having a crystal structure of ABtype is not higher than 10% by volume including 0% by volume and the hydrogen absorbing alloy has a composition represented by general formula (1) given below:RMgTNiM1M2Mn. &#x2003;&#x2003;(1)

Hydrogen-absorbing alloy, secondary battery, hybrid car and electromobile

Hydrogen-absorbing alloy and secondary battery

Nickel-hydrogen secondary battery

Hydrogen-absorbing alloy, electrode and secondary battery

A nickel-hydrogen secondary battery having a negative electrode comprising a hydrogen-absorbing alloy containing magnesium, a rare earth element and nickel as essential elements, which is capable of suppressing the self-discharge being occurred under the condition of high temperature storage, or the like. This secondary battery comprises a negative electrode containing a hydrogen-absorbing alloy, a positive electrode containing nickel hydroxide, a separator comprising a non-woven fabric, and an alkaline electrolyte. The hydrogen-absorbing alloy is represented by (R,Mg,)Ni,A,(wherein R is at least one element selected from rare earth elements (including yttrium), Ca, Zr and Ti, A is at least one element selected from Co, Mn, Fe, V, Cr, Nb, Al, Ga, Zn, Sn, Cu, Si, P and B), and x, y and z are atomic ratio individually defined as 0<x<1, 0&lE;z&lE;1.5, 2.5&lE;y&plus;z<4.5). The ratio between the weight of the hydrogen-absorbing alloy per unit area of the negative electrode (M,(mg/cm,)) and the weight per unit area of the separator (M,(g/m,)) meets the condition of M,/M,&lE;6.

There is provided a hydrogen-absorbing alloy which contains an alloy ingot manufactured by means of a casting or sintering method or a pulverized product of the alloy ingot, and the alloy ingot being represented by the following general formula (1),

Hydrogen-absorbing alloy

Hydrogen-storage alloy and alkali secondary battery using same

A hydrogen-absorbing alloy for battery according to the present invention comprises an alloy having the composition represented by a general formula A Ni.sub.a Mn.sub.b M.sub.c �where, A is at least one kind of element selected from rare earth elements including Y (yttrium), M is a metal mainly composed of at least one kind of element selected from Co, Al, Fe, Si, Cr, Cu, Ti, Zr, Zn, Hf, V, Nb, Ta, Mo, W, Ag, Pd, B, Ga, In, Ge and Sn, 3.5.ltoreq.a.ltoreq.5, 0.1.ltoreq.b.ltoreq.1, 0.ltoreq.c.ltoreq.1, 4.5.ltoreq.a+b+c.ltoreq.6!, wherein the alloy has columnar structures in which the area ratio of the columnar structures having the ratio of a minor diameter to a major diameter (aspect ratio) of 1:2 or higher is 50% or more. Further, an average minor diameter of the columnar structures is set to 30 microns or less. With this arrangement, there can be provided a nickel-metal hydride battery capable of satisfying the three leading characteristics of a high electrode capacity, long life and good rising-up all together.

Hydrogen-absorbing alloy for battery, method of manufacturing the same,

There is provided a hydrogen-absorbing alloy for battery comprising a rapidly-quenched alloy having the composition represented by a general formula ANi.sub.a M.sub.b M'.sub.c T.sub.d (where, A is composed of La, Ce, Pr, Nd and Y, an amount of La content in A is 50-99 wt %, an amount of Ce content is 1-30 wt %, an amount of Pr content is 0-10 wt %, an amount of Nd content is 0-10 wt % and an amount of Y content is 0-10 wt %; M is at least one element selected from Co, Fe and Cu; M' is at least one element selected from Mn and Al; T is at least one element selected from B, Si, S, Cr, Ga, Ge, Mo, Ru, Rh, Pd, Ag, In, Sn, Sb, Bi, P, V, Nb, Ta and W; and a, b, c and d are atomic ratios and satisfy 3.2.ltoreq.a.ltoreq.4.0, 0.4.ltoreq.b.ltoreq.1.0, 0.3.ltoreq.c.ltoreq.0.8, 0.ltoreq.d.ltoreq.0.2, 4.9.ltoreq.a+b+c+d.ltoreq.5.4), characterized in that a hydrogen equilibrium pressure when the number of hydrogen atoms absorbed by one atom of the alloy at a temperature of 60.degree. C. is 0.4 is 0.05-0.6 atm. With the above arrangement, a hydrogen-absorbing alloy capable of realizing a small decrease in capacity under the low-temperature area and high-temperature area, a large electrode capacity in a wide temperature range, and a long life, and a secondary nickel-metal hydride battery using this alloy can be obtained.

Hydrogen-absorbing alloy for battery and secondary nickel-metal hydride

A hydrogen-absorbing alloy for battery according to the present invention comprises an alloy having the composition represented by a general formula A Ni.sub.a Mn.sub.b M.sub.c [where, A is at least one kind of element selected from rare earth elements including Y (yttrium), M is a metal mainly composed of at least one kind of element selected from Co, Al, Fe, Si, Cr, Cu, Ti, Zr, Zn, Hf, V, Nb, Ta, Mo, W, Ag, Pd, B, Ga, In, Ge and Sn, 3.5.ltoreq.a.ltoreq.5, 0.1.ltoreq.b.ltoreq.1, 0.ltoreq.c.ltoreq.1, 4.5.ltoreq.a+b+c.ltoreq.6], wherein the alloy has columnar structures in which the area ratio of the columnar structures having the ratio of a minor diameter to a major diameter (aspect ratio) of 1:2 or higher is 50% or more. Further, an average minor diameter of the columnar structures is set to 30 microns or less. With this arrangement, there can be provided a nickel-metal hydride battery capable of satisfying the three leading characteristics of a high electrode capacity, long life and good rising-up all together.

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Yokohama, Japan

Takamichi Inaba