Abstract: There is provided a hydrogen-absorbing alloy comprising, as a principal phase, at least one kind of phase selected from the group consisting of a first phase having a hexagonal crystal system (excluding a phase having a CaCu5 type crystal structure) and a second phase having a rhombohedral crystal system, the hydrogen-absorbing alloy having a composition represented by the following general formula (1):

Abstract: There is provided a hydrogen-absorbing alloy comprising, as a principal phase, at least one kind of phase selected from the group consisting of a first phase having a hexagonal crystal system (excluding a phase having a CaCu5 type crystal structure) and a second phase having a rhombohedral crystal system, the hydrogen-absorbing alloy having a composition represented by the following general formula (1): R1−a−bMgaTbNiZ−X−Y−&agr;M1XM2YMn60   (1) wherein R is at least one kind of element selected from rare earth elements (which include Y), T is at least one element selected from the group consisting of Ca, Ti, Zr and Hf, M1 is at least one element selected from the group consisting of Co and Fe, M2 is at least one element selected from the group consisting of Al, Ga, Zn, Sn, Cu, Si, B, Nb, W, Mo, V, Cr, Ta, Li, P and S, and the atomic ratios of a, b, X, Y, &agr; and Z are respectively a number satisfying the conditions of: 0.15≦a≦0.37, 0≦b≦0.3, 0≦X≦1.

Abstract: There is provided a nickel-hydrogen secondary battery which comprises a negative electrode comprising a hydrogen-absorbing alloy represented by the following general formula (A), a positive electrode, and an alkaline electrolyte, and which meets the conditions represented by the formulas (1) and (2), (R1-xMgx)NiyAz   (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≦z≦1.5, 2.5≦y+z<4.5, 3.2≦P≦5.0   (1) 0.9≦Q≦0.2P+0.7   (2) wherein P is a quantity (g) of the hydrogen-absorbing alloy per theoretical capacity 1 Ah of the positive electrode, and Q is a quantity (mL) of the alkaline electrolyte per theoretical capacity 1 Ah of the positive electrode.

Abstract: 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 (R1−xMgx)NiyAz (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≦z≦1.5, 2.5≦y+z<4.5).

Abstract: 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),(Mg.sub.1-a-b R1.sub.a M1.sub.b)Ni.sub.z (1)wherein R1 is at least one element selected from rare earth elements (including Y), M1 is at least one element selected from elements having a larger electronegativity than that of Mg (excluding the elements of R1, Cr, Mn, Fe, Co, Cu, Zn and Ni), and a, b and z are respectively a number satisfying conditions 0.1.ltoreq.a.ltoreq.0.8, 0<b.ltoreq.0.9, 1-a-b>0, and 3.ltoreq.z.ltoreq.3.8.

Abstract: A nickel-hydrogen secondary battery comprising, a positive electrode containing nickel hydroxide, a negative electrode containing a hydrogen-absorbing alloy, a separator interposed between the positive electrode and the negative electrode and containing olefin-containing-polymer based fibers having an ion-exchange group, and an alkaline electrolyte having a normality of 5 or more in concentration, wherein the separator satisfies the following equation (1):{0.409-(X/55)}.ltoreq.Y.ltoreq.{0.636+(2X/55)} (1)where X is a chemical equivalent of alkaline electrolyte per 1 Ah of battery capacity (meq/Ah) and Y is an ion-exchange capacity of the separator per 1 Ah of battery capacity (meq/Ah).

Abstract: A nickel-hydrogen secondary battery is disclosed wherein a long life is assured, an improved self-discharging property in a high temperature storage and the inhibition of increase in inner pressure of the battery in the occasion of over-charging can be realized. The nickel-hydrogen secondary battery comprises, a case, a paste-type positive electrode accommodated in the case and containing nickel hydroxide and a polymeric binder, a paste-type negative electrode accommodated in the case and containing a hydrogen-absorbing alloy and a polymeric binder, a separator accommodated in the case in so as to be interposed between the positive and negative electrodes, and an alkali electrolyte accommodated in the case.

Abstract: A hydrogen absorption alloy electrode is manufactured by a dry method in which a fluorine resin powder in an amount of 0.5 to 5.0%, based on the weight of the electrode, is with a hydrogen absorption alloy powder while applying a sufficient shearing force such that the fluorine resin powder is turned into an aggregate of monofilaments each having a diameter D of about 5 to 100 microns, a length L of about 100 to 500 microns, and an aspect ratio L/D of 10 to 100, so as to prepare a cotton-like mixture. The cotton-like mixture is placed on a conductive substrate acting as a current collector, and shaped by a roll pressing.

Abstract: A nickel-metal hydride secondary cell comprising an enclosure, a non-sinter type nickel positive electrode accommodated in said enclosure and formed of a conductive core and a layer formed on the core and made mainly of a binding medium, nickel hydroxide powder, and cobalt monoxide powder, a hydrogen absorbing alloy negative electrode accommodated in said enclosure and formed of punched metal and a layer formed on the punched metal by applying a paste thereto, said punched metal having a plurality of apertures having a diameter of 1 to 5 mm at an aperture rate of 45 to 70% and having a thickness equal to 10 to 35% of the overall thickness of the negative electrode, and said paste made of 100 parts by weight of hydrogen absorbing alloy powder, 0.005 to 1 part by weight of polyacrylate, 0.01 to 1 part by weight of carboxymethylcellulose, 0.5 to 7 parts by weight of fluoro-resin, and 0.

Abstract: A nickel-metal hydride secondary cell comprising a non-sinter type nickel positive electrode accommodated in an enclosure and comprised of a conductive core and a layer formed on the conductive core, the layer made of a mixture of nickel hydroxide power and cobalt monoxide powder covered with a layer of high-valence cobalt oxide, a hydrogen absorbing alloy negative electrode accommodated in the enclosure and comprised of a conductive core and a layer formed on the conductive core and made of a mixture hydrogen absorbing alloy powder and carbon black having a specific surface area of 700 m.sup.2 /g or more, and having a capacity 1.0 to 2.5 times the sum of the capacity of the nickel hydroxide contained in the positive electrode and the electricity required to oxidize the cobalt monoxide powder, a separator made of synthetic resin unwoven fabric having a texture size of 50 to 100 g/m.sup.2 and a thickness of 0.1 to 0.