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: The present invention provides a non-stoichiometric alloy comprising a composition having the formula AB5+X an atomic ratio wherein A is selected from the group consisting of the rare earth metals, yttrium, mischmetal, or a combination thereof; B is nickel and tin, or nickel and tin and at least a third element selected from the group consisting of the elements in group IVA of the periodic table, aluminum, manganese, iron, cobalt, copper, antimony or a combination thereof; X is greater than 0 and less than or equal to about 2.0; and wherein at least one substituted A site is occupied by at least one of the B elements. An electrode incorporating said alloy and an electrochemical cell incorporating said electrode are also described.

Abstract: Provided is a hydrogen absorbing alloy powder for use in nickel-metal hydride storage batteries having a high capacity, excellent initial characteristics and a long life. Specifically provided is a process for the production of a hydrogen absorbing alloy powder which includes the steps of treating a hydrogen absorbing alloy powder with an acid solution, and subsequently treating the hydrogen absorbing alloy powder with a solution containing a condensed phosphoric acid having 2 to 20 phosphorus atoms per molecule and/or phytic acid, as well as an electrode formed of the hydrogen absorbing alloy powder produced by the above process.

Abstract: A hydrogen-absorbing alloy electrode for an alkaline secondary battery. The electrode is made from a hydrogen-absorbing alloy containing nickel which has been treated with an acidic solution containing a chelating agent for nickel. The hydrogen-absorbing alloy electrode has good activity and a nickel-hydrogen battery having the hydrogen-absorbing alloy electrode as a negative electrode has a large high rate discharge capacity soon after being assembled, and inhibits an increase of internal pressure during discharge.

Abstract: There is provided a hydrogen-absorbing alloy comprising at least one crystal phase consisting essentially of at least one unit cell which has a laminate structure comprising at least one A2B4 subcell and at least one AB5 subcell, and the aforementioned at least one unit cell satisfying the following formula (1), 0.5<X<1  (1) wherein A is at least one kind of element which is capable of generating heat of formation &Dgr;H (kJ/mol) of less than 20 kJ/mol at the occasion of generating a hydride from one mole of hydrogen at a temperature of 25° C., B is at least one kind of element which is capable of generating heat of formation &Dgr;H (kJ/mol) of not less than 20 kJ/mol at the occasion of generating a hydride from one mole of hydrogen at a temperature of 25° C., and X is a ratio in number of the aforementioned at least one A2B4 subcell to the aforementioned at least one AB5 subcell.

Abstract: An AB2C2-type ternary hydrogen storage alloy comprising an AB2C2 phase as main ingredient, where A comprises at least one of a rare-earth element and Ca, B mainly comprises Mg, and C comprises at least one of transition metal elements of Cu, Ni, Co, Fe, Cr, Mn, Ti, V and Zn, and x and y represent values within the-ranges of 1.5≦x≦2.5 and 1.5 ≦y≦3.

Abstract: Disclosed is a hydrogen storage alloy electrode for use in alkaline storage batteries that can reduce internal resistance of the battery and can give an excellent output characteristic and a long cycle life to the battery. The electrode comprises an AB5-type hydrogen storage alloy powder, a yttrium compound and a compound of a light rare earth element. The total content of the yttrium compound and the compound of a light rare earth element is in a range of 0.5 to 2.0 parts by weight per 100 parts by weight of hydrogen storage alloy powder. Preferable ratios of the yttrium compound and the compound of a light rare earth element selected from La, Ce, Pr and Nd are, respectively, 60 wt % or more and 7 wt % or less in the total amount of the yttrium compound and the compound of the light rare earth element.

Abstract: A hydrogen storage alloy of the AB5-type, where the A component includes La and/or Nd and at least 0.4 mole fraction Pr, as well as batteries including the alloy, are disclosed.

Abstract: Hydrogen propelled vehicles and fundamentally new magnesium-based hydrogen storage alloy materials which for the first time make it feasible and practical to use solid state storage and delivery of hydrogen to power internal combustion engine or fuel cell vehicles. These exceptional alloys have remarkable hydrogen storage capacity of well over 6 weight % coupled with extraordinary absorption kinetics such that the alloy powder absorbs 80% of its total capacity within 2 minutes at 300° C.

Abstract: The present invention relates to a method and apparatus of manufacturing nickel-metal-hydride alloy powder material. The furnace charge of nickel-metal-hydride alloy is melted in vacuum or argon atmosphere in this invention. After melting, the molten alloy is gas atomized to fine spherical powder or centrifugal atomized to flaky shape. Then the powders are fed into a hydrogen heat treatment chamber for hydrogen heat treatment and pulverization. This invention integrates the melting, pulverizing and hydrogen treatment of nickel-metal hydride alloy powder into a whole step. It can charge and pulverize continuously and is suitable for the large-scale industrialized production of homogeneous composition and least segregation nickel-metal hydride alloy powder.

Abstract: An active composition for an electrode of an electrochemical cell. The active composition comprises an electrode material, and a nonfibrillating polymeric binder. The polymeric binder may comprise a fluoradditive. Also disclosed in an electrode and an electrochemical cell comprising the active composition.

Abstract: This invention pertains to improved formulations of platinum--molybdenum alloys for use as anode catalysts. These electrocatalysts find utility as a constituent of gas diffusion electrodes for use in fuel cells that operate at less than 180.degree. C. or in applications whereupon hydrogen is oxidized in the presence of carbon monoxide or other platinum inhibiting substances. The new formulations derive unexpected activity through creating highly dispersed alloy particles of up to approximately 300 .ANG. on carbon supports. The desired activity is achieved by carefully controlling the platinum to molybdenum ratio during preparation and judiciously selecting a proper loading of alloy on the carbon support.

Abstract: A method for introducing hydrogen into layered nanostructures. The method comprises: a) treating the layered nanostructures with an inert gas at a temperature of at least about 800.degree. C. for an effective amount time; and b) introducing hydrogen into said nanostructures by subjecting the nanostructures to flowing hydrogen at a pressure from about 1,000 psig to about 3,000 psig. The layered nanostructures are characterized as possessing: at least some crystallinity, interstices from about 0.335 nm to 0.67 nm, and sorption properties with respect to hydrogen at those surfaces of the nanostructure which define the interstices. Preferred layered nanostructures are carbon nanostructures such as those selected from carbon nanotubes, carbon fibrils, carbon nanoshells, and carbon nanofibers. Hydrogen is chemisorbed into the interstices of the nanostructures.

Abstract: A hydrogen-absorbing alloy capable of controlling the very fine structure formed by a spinodal decomposition for improving flatness of an emission equilibrium pressure in a practical temperature/pressure range and excellent in activation and hydrogen absorption/desorption amounts, and a production method thereof. The hydrogen-absorbing alloy has a composition expressed by the general formula Ti.sub.x Cr.sub.y V.sub.z (where each of x, y and z represents an atomic percent and satisfies the relation x+y+z=100), wherein the composition has a body-centered cubic structural phase as a principal phase, the principal phase exists within the range in which the body-centered cubic structure appears and a spinodal decomposition occurs with the exception of a C14 (a typical structure of the Laves phase; a MgZn.sub.2 type crystal structure) mono-phase range, and has a regular periodical structure formed by the spinodal decomposition, and its apparent lattice constant is at least 0.2950 nm but is not greater than 0.

Abstract: A hydrogen absorbing alloy electrode having on a conductive support a layer which contains as a main component a hydrogen absorbing alloy powder capable of absorbing and releasing hydrogen electrochemically and is covered with a fluorine-containing water repellent layer on the surface side; with the fluorine-containing water repellent layer being a layer formed by coating and curing a water repellent agent comprising (A) a straight-chain perfluorinated compound having at least two secondary amino groups per molecule and a divalent perfluoroalkylene or perfluoropolyether structure in the main chain and (B) a fluorine-containing epoxy compound having at least three epoxy groups per molecule.

Abstract: Hydrogen lithium titanate prepared by an acid process of lithium titanate and having pH of 11.2 or smaller or hydrogen lithium titanate expressed by general formula H.sub.x Li.sub.y-x Ti.sub.z O.sub.4 (where y.gtoreq.x>0 0.8.ltoreq.y.ltoreq.2.7 and 1.3.ltoreq.z.ltoreq.2.2) is disclosed. Hydrogen lithium titanate may be employed as active materials of positive and negative electrodes of a non-aqueous electrolyte secondary battery thereby realizing a charging capacity greater than a theoretical capacity. It is preferable that hydrogen lithium titanate is formed into a particle shape and includes voids in the particles. It is preferable that the largest particle size is 0.1 .mu.m to 50 .mu.m and the specific surface area is 0.01 m.sup.2 /g to 300 m.sup.2 /g. Hydrogen lithium titanate of the foregoing type can be manufactured by bringing lithium titanate into contact with an acid, such as acetic acid, to substitute protons for lithium ions.

Abstract: This invention relates to a hydrogen absorbing electrode, in which a rare earth element having a basicity weaker than that of La is mixed to a hydrogen absorbing alloy or contained in it for serving as a component element. The invention relates to a nickel electrode, in which a rare earth element is mixed to a nickel hydroxide or contained in it as a solid solution. The invention further relates to an alkaline storage battery, in which a rare earth element is coated on a surface of a nickel electrode or a surface of a separator.

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: Steam is contacted with a hydrogen absorbing alloy in a temperature range from 200.degree. C. to 400.degree. C. With a contact catalytic reaction of water, a metal contained in the hydrogen absorbing alloy is changed to an oxide or a hydroxide. Hydrogen produced causes the Ni compound to be reduced and thereby the Ni metal that is catalytically active is produced. Thus, the surface of the hydrogen absorbing alloy is activated. The steam is contained in an inert gas or a reductive gas. This treatment method is suitable as an activation treatment for a hydrogen absorbing alloy used as an active material of a negative electrode of a secondary battery.

Abstract: The hydrogen-absorbing alloy electrode for alkaline storage batteries according to the invention comprises a hydrogen absorbing alloy powder prepared by grinding a strip of hydrogen absorbing alloy produced by solidifying a molten alloy by a roll method and satisfying the following relations:r/t.ltoreq.0.5 (1)60.ltoreq.t.ltoreq.180 (2)30.ltoreq.r.ltoreq.90 (3)wherein r represents the mean particle size (.mu.m) of the hydrogen absorbing alloy powder and t represents the mean thickness (.mu.m) of the strip absorbing alloy. The hydrogen absorbing alloy electrode of this invention features an improved high-rate discharge characteristic at low temperature.

Abstract: A hydrogen absorbing alloy composition for a nickel-hydrogen secondary battery which includes LnNi.sub.5 hydrogen absorbing alloy, where Ln represents at least one rare-earth element. The hydrogen absorbing alloy composition also includes at least one compound selected from the group consisting of heavy rare-earth oxides, heavy rare-earth hydroxides, compound oxides including at least one rare-earth element and compound hydroxides including at least one rare-earth element. Rare-earth elements can be selected from the group consisting of La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu. Exemplary hydrogen absorbing alloy compositions include La alone or in combination with one other rare-earth element, such as Ce, Pr, Nd, or Sm. Exemplary rare-earth oxides include Yb.sub.2 O.sub.3, Er.sub.2 O.sub.3 and GdO.sub.3 and exemplary rare-earth hydroxides include Yb(OH).sub.3 and Er(OH).sub.3.

Abstract: There are disclosed Mm/Ni type hydrogen storage alloys for Ni/MH secondary cells. The alloys which allow the cells to be of high performance and high capacity can be prepared at lower costs than the production costs of conventional Co-rich hydrogen storage alloys, by reducing the amount of the Co element. The Co element is partially or wholly replaced by by Cr, Cu, Fe, Zn and/or Zi, which are each known to be of stronger affinity for hydrogen than is Co and to have such a strong oxidation tendency in electrolytes as to form a highly dense oxide. The novel alloys have discharge capacities and electrode life span as good as those of the conventional Co-rich hydrogen storage alloys but have advantages over the Co-rich alloys, including performance-to-cost.

Abstract: A mechanically alloyed hydrogen storage material having 75-95 atomic percent Mg, 5-15 atomic percent Ni, 0.5-6 atomic percent Mo, and at least one additional element selected from the group consisting of Al, C, Ca, Ce, Co, Cr, Cu, Dy, Fe, La, Mn, Nd, Si, Ti, V, and Zr, preferably between 1-15 atomic %. The mechanically alloyed hydrogen storage preferably contains from 3-15 atomic % C and at least one other element selected from the group consisting of Al, Ca, Ce, Cu, Dy, Fe, La, Mn, and Nd. The hydrogen storage materials are created by mechanical alloying in a milling apparatus under an inert atmosphere, such as argon, or a mixed atmosphere, such as argon and hydrogen. The speed and length of the milling are varied.

Abstract: A method of producing a hydrogen absorbing alloy powder, which comprises a step of treating a pulverized hydrogen absorbing alloy with an acidic or alkaline solution of conjugated unsaturated compound having at least 5 conjugated .pi. bonds; and a negative electrode using a hydrogen absorbing alloy powder produced by the aforesaid method, which can ensure high initial activity and high initial capacity in the nickel-hydrogen secondary battery provided therewith.

Abstract: A Ni based hydrogen occluding alloy having the composition, comprising: by weight:(i) 32-38% of at least one of La or Ce,(ii) 0.1-17% Co,(iii) 0.1-3.5% Al,(iv) 0.5-10% Mn,(v) 0.005-0.1% of hydrogen, withthe balance being Ni and unavoidable impurities, wherein said alloy has a microstructure of a phase having a Ce.sub.2 Ni.sub.7 -type crystal structure and rare earth element hydride dispersively distributed in a matrix having a CaCu.sub.5 -type crystal structure and, wherein the amount of said phase having a Ce.sub.2 Ni.sub.7 -type crystal structure is 1-40% by area and the amount of said rare earth element hydride is 0.5-20% by area.

Abstract: A method of making hydrogen storage powder resistant to fracture in service involves forming a melt having the appropriate composition for the hydrogen storage material, such, for example, LaNi.sub.5 and other AB.sub.5 type materials and AB.sub.5+x materials, where x is from about -2.5 to about +2.5, including x=0, and the melt is gas atomized under conditions of melt temperature and atomizing gas pressure to form generally spherical powder particles. The hydrogen storage powder exhibits improved chemcial homogeneity as a result of rapid solidfication from the melt and small particle size that is more resistant to microcracking during hydrogen absorption/desorption cycling. A hydrogen storage component, such as an electrode for a battery or electrochemical fuel cell, made from the gas atomized hydrogen storage material is resistant to hydrogen degradation upon hydrogen absorption/desorption that occurs for example, during charging/discharging of a battery.

Abstract: The present invention aims to provide a method of producing a hydrogen absorbing alloy electrode which is solid and enables a metal hydride storage cell, using the hydrogen absorbing alloy electrode, with high discharge characteristics in high-rate discharge and in low temperature and a long cycle life. To achieve this, the hydrogen absorbing alloy electrode is produced by firstly generating a first powder by giving a surface treatment to a hydrogen absorbing alloy powder in an acid solution, secondly generating a mixed material by mixing the first powder with a second powder which is composed of a metal which does not absorb hydrogen and/or an alloy which does not absorb hydrogen, thirdly attaching the mixed material to a base plate, and fourthly baking the base plate for sintering the mixed material attached to the base plate.

Abstract: In the present invention, a hydrogen absorbing alloy treated upon immersed in an acid solution containing at least a quinone compound, a hydrogen absorbing alloy immersed in water to which at least a quinone compound is added, or a hydrogen absorbing alloy treated upon being immersed in an acid solution containing at least a quinone compound and then immersed in water to which at least a quinone compound is added is used for a hydrogen absorbing alloy electrode, and the hydrogen absorbing alloy electrode is used as a negative electrode of an alkali secondary battery.

Abstract: A hydrogen absorbing alloy is provided which is increased in reaction rate without being restricted in composition and which is unimpaired in the reversibility of reaction and hydrogen absorption-desorption cycle life characteristics. The alloy contains the phase of an intermetallic compound of the composition A5T19 wherein A is at least one element selected from the group consisting of La, Ce, Pr, Sm, Nd, Mm (misch metal), Y, Gd, Ca, Mg, Ti, Zr and Hf, and T is at least one element selected from the group consisting of B, Bi, Al, Si, Cr, V, Mn, Fe, Co, Ni, Cu, Zn, Sn and Sb. The alloy is produced by mixing together an alloy containing an AT3 phase and an alloy containing an AT4 phase, mechanically alloying the mixture to form the phase of intermetallic compound of the composition A5T19 in addition to the AT3 and AT4 phases, and subsequently mixing together or mechanically alloying the resulting alloy and an alloy containing AT5 phase.

Abstract: A hydrogen absorbing electrode containing a hydrogen absorbing alloy consisting mainly of AB.sub.3 type crystal-structure phase and represented by the following formula (I) is providedR(Ni.sub.1-x M.sub.x).sub.z (I)wherein R is at least one element selected from rare earth elements (including Y), M is at least one element selected from the group consisting of Al, Ga, Zn, Sn, Cu, Si, Ag, In, Ti, Zr, Hf, V, Nb, Ta, Cr, Fe, Mn, Mo and W, and x and z are respectively a number satisfying conditions 0.01.ltoreq.x.ltoreq.0.2, and 2.5<z<3.25.

Abstract: A method of producing an age precipitation-containing rare earth metal-nickel alloy of AB.sub.5 type having a composition represented by a formula (1)R(ni.sub.1-x M.sub.x).sub.5+y (1)wherein R stands for a rare earth element including Y or mixtures thereof, M stands for Co, Al, Mn, Fe, Cu, Zr, Ti, Mo, W, B, or mixtures thereof, x satisfies the relation of 0.05.ltoreq.x.ltoreq.0.5, and y satisfies the relation of -0.45.ltoreq.y.ltoreq.0.45, the alloy containing a precipitated phase having an average size of 0.1 to 20 .mu.m as measured along the longitudinal axis is disclosed. The method includes the steps of subjecting a raw alloy material having a composition represented by the formula (1) to a solid solution treatment at a temperature of not less than 1000.degree. C. and ageing the alloy material subjected to said solution heat treatment at a temperature T (.degree. C) of not less than 700.degree. C. and less than 1000.degree. C.

Abstract: A powder of an alloy of Ni and Mg, La, Be or Li, consisting of crystallites having a grain size lower than 100 nm and a crystalline structure allowing hydrogen absorption. This powder which is preferably obtained by mechanical grinding, may consist of cristallites of Mg.sub.2 Ni, LaNi.sub.5 or of Ni-based alloys of Be or Li having a grain size lower than 100 nm. The powder may also consist of cristallites of formula Mg.sub.2-x Ni.sub.1+x, x ranging from -0.3 to +0.3, which have a grain size lower than 100 nm, and preferably lower than 30 nm. This crystalline powder is particularly useful for storing and transporting hydrogen. Indeed, it has been discovered that such Ni-based nanocrystalline powder requires no or only one single activation treatment at low temperature to absorb hydrogen. It has also been discovered that the kinetic of absorption and diffusion of hydrogen within the powder is much faster. This can be explained by the presence of a large number of grain boundaries.

Abstract: The present invention provides a hydrogen storage alloy electrode high in capacity and exceptional in cycle life characteristic by improving a conventional V-based hydrogen storage alloy of a body-centered cubic structure. The electrode comprises particles of a hydrogen storage alloy represented by the general formula V.sub.1-a-b-c-d Ti.sub.a Cr.sub.b M.sub.c L.sub.d, wherein M is at least one element selected from the group consisting of Mn, Fe, Co, Cu, Nb, Zn, Zr, Mo, Ag, Hf, Ta, W, Al, Si, C, N, P and B, and L is at least one element selected from the group consisting of Y and rare earth elements, and 0.2.ltoreq.a.ltoreq.0.5, 0.1.ltoreq.b.ltoreq.0.4, 0.ltoreq.c.ltoreq.0.2 and 0<d.ltoreq.0.03, the alloy having a body-centered cubic structure. The alloy particles preferably have their surface disposed with an Ni-diffused layer.

Abstract: There are disclosed a powdery material comprising a hydrogen-storing compound comprising a core layer of a hydrogen-storing alloy coated with a transition metal oxide layer and having a transition metal dispersed and carried on the outermost surface thereof, an electrode member for alkali secondary cells using the powdery material comprising a hydrogen-storing compound, and a secondary cell using the electrode member as an electrode. With such an alkali secondary cell, a strong resistance to overcharge, a high charging and discharging efficiency and a long cycle life can be implemented.

Abstract: By using a thin film-formed positive electrode, and negative electrode and a film separator, the capacity density of the electrode plate can be improved and at the same time a nickel-hydrogen secondary battery with a higher capacity can be easily obtained; as a result a nickel-hydrogen secondary battery with a higher capacity density can be provided.

Abstract: The present invention provides alkaline storage batteries of which high-rate discharge characteristic at low-temperature, cycle life, and storage performance at high-temperature are improved in good balance and the cost performance is superior even when the content of cobalt is made extremely low by using in the negative electrode consisting of hydrogen absorbing alloy powders based on MmNi system alloys comprising MmNi.sub.5 system alloy which remains mostly crystalline in phase when absorbing hydrogen and Mm.sub.2 Ni.sub.7 system alloy which turns mostly amorphous in phase upon absorbing hydrogen.

Abstract: A hydrogen-storage alloy containing as a component element thereof an element easily reactive with hydrogen to be selected from among the elements of Group 1A, Group 1A, Group 3A, Group 4A, and Group 4A in the Periodic Table of the Elements and having a quasi-crystalline phase as at least part of the component phases thereof. The quasi-crystalline phase has an element of axial rotation selected from among 5-fold, 8-fold, 10-fold, and 12-fold symmetric axis. The hydrogen-storage alloy exhibits outstanding resistance to corrosion, permits effective prevention of comminution, and further excels in terms of the abundance of hydrogen to be absorbed and released.

Abstract: A hydrogen absorbing alloy is disclosed for use as the negative electrode in alkaline batteries. The general formula of the alloy is AB.sub.x M.sub.y, wherein A is selected from the rare earth element La or a mischmetal thereof; B is selected from the group consisting of Ni, Fe, Mn, Cr, Cu, Co, and mixtures thereof; M is selected from the group consisting of Al, In, Zn, Sn, Ga, Si, Ge, Bi, and mixtures thereof; 4.5.ltoreq.x.ltoreq.5.5; and 0.3<y.ltoreq.0.6. This alloy has a longer cycle life, along with larger capacity and better reactivity.

Abstract: The methods of the present invention provide efficient mechanical milling or alloying of stock materials of titanium and aluminum in order to increase yield of the titanium stock and reduce cost in connection with the production of a titanium-aluminum-based alloy sinter. Sponge titanium, which has a particle size of 1 to 20 mm and which contains hydrogen at 3.5 mass % or more, is used as the titanium stock. The sponge titanium is ball-milled with an aluminum stock in an argon atmosphere to produce a hydrogen-containing titanium-aluminum-based alloy powder. Furthermore, this powder may be sintered, as required.

Abstract: In the present invention, a hydrogen absorbing alloy containing at least nickel, cobalt and aluminum, in which the sum a of the respective abundance ratios of cobalt atoms and aluminum atoms in a portion to a depth of 30 .ANG. from its surface and the sum b of the respective abundance ratios of cobalt atoms and aluminum atoms in a bulk region inside thereof satisfy conditions of a/b.gtoreq.1.30, or a hydrogen absorbing alloy containing at least nickel, cobalt, aluminum and manganese, in which the sum A of the respective abundance ratios of cobalt atoms, aluminum atoms and manganese atoms in a portion to a depth of 30 .ANG. from its surface and the sum B of the respective abundance ratios of cobalt atoms, aluminum atoms and manganese atoms in a bulk region inside thereof satisfy conditions A/B.gtoreq.1.20 is used for a hydrogen absorbing alloy electrode in an alkali secondary battery.

Abstract: Mechanically alloyed hydrogen storage materials having a major atomic percentage of magnesium and a minor atomic percentage of at least two elements selected from the group consisting of nickel, molybdenum, iron and titanium. Preferably the mechanical alloy comprises a multi-phase material, including at least one amorphous phase. Also, the at least two elements are preferably either nickel (from about 5 to 15 at. %) and molybdenum (from about 0.5 to 5 at. %) or iron (from about 5 to 15 at. %) and titanium (from about 5 to 15 at. %). The hydrogen storage materials are created by mechanical alloying in a milling apparatus under an inert atmosphere, such as argon, or a mixed atmosphere, such as argon and hydrogen. The speed and length of the milling are varied.

Abstract: A powder of a hydrogen storage alloy which comprises metallic nickel in or on the surfaces of the powder in an amount sufficient to impart a magnetization intensity of 0.5 to 6 emu/g to the powder. The powder has a specific surface area of 0.15 to 0.7 m.sup.2 /g when determined according to a BET adsorption method, an oxygen concentration of 0.15 to 1.5 wt %, and an average particle size of 10 to 100 .mu.m, with a size distribution wherein the content of particles having a size of 8 .mu.m or below is in the range of 30 wt % or below. An electrode for secondary cells is also described, which comprises the powder defined above.

Abstract: This invention relates to a hydrogen-absorbing alloy, and particularly provides a hydrogen-absorbing alloy having a body-centered cubic structure which has a periodical structure formed by spinodal decomposition, has a large hydrogen storage amount, has excellent hydrogen desorption characteristics and can mitigate activation conditions, the alloy comprises at least two elements of alloy components, wherein the relational curve between chemical free energy of solid solutions and an alloy composition has a shape describing an upwardly convexed curve, or said alloy comprises two solid solutions having a regular periodical structure formed by spinodal decomposition within a region satisfying the relation d.sup.2 G/dX.sub.B.sup.2 <0 (where G is chemical free energy and X.sub.B is a solute alloy concentration) as the principal phase.

Abstract: The present invention provides a scandium containing hydrogen absorption alloy having an alloy phase which is represented by the following formula;(Sc.sub.x A.sub.1-x)(B'.sub.y B".sub.2-y).sub.zwherein A is at least one of Ti, Zr, rare-earth elements, a mixture of Ti and at least one of Zr, Ta, Nb, Hf, Ca and rare-earth elements, and a mixture of Zr and at least one of Ti, Ta, Nb, Hf, Ca and rare-earth elements; B'is at least one of Ni, Fe, Co and a mixture of at least one of Ni, Fe and Co and at least one of Al, Ga, Si and In; B" is at least one of Mn, V, Cr, Nb, Ti and a mixture of at least one of Mn, V, Cr, Nb and Ti and at least one of Al, Ga, Si and In; x represents 0<x.ltoreq.1; y represents 0<y<2; and z represents 0.75.ltoreq.z.ltoreq.1.2, and the alloy phase includes at least one of a part which belongs to a C15 type Laves phase and a part which belongs to a C14 type Laves phase, and a hydrogen absorption electrode which includes the alloy.

Abstract: Provided is a hydrogen absorbing alloy electrode having on a conductive support surface a hydrogen absorbing alloy layer which comprises a hydrogen absorbing alloy powder capable of absorbing and desorbing hydrogen electrochemically and a binder; with the hydrogen absorbing alloy layer having a surface coated spotwise with an amorphous water-repelling fluoropolymer at a total coverage of 0.001 mg/cm.sup.2 to 5 mg/cm.sup.2, wherein a solution of the fluoropolymer in a solvent having a boiling point of 50.degree.-110.degree. C. is spray-coated on the alloy layer surface.

Abstract: Disclosed is a very light-weight, Mg and Be-based material which has the ability to reversibly store hydrogen with very good kinetics. This material is of the formula (M.sub.1-x A.sub.x) D.sub.y wherein M is Mg, Be or a combination of them; A is an element selected from the group consisting of Li, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Al, Y, Zr, Nb, Mo, In, Sn, O, Si, B, C and F; D is a metal selected from the group consisting of Fe, Co, Ni, Ru, Rh, Pd, Ir and Pt (preferably Pd); x is a number ranging from 0 to 0.3; and y is a number ranging from 0 to 0.15. This material is in the form of a powder of particles of the formula M.sub.1-x A.sub.x as defined hereinabove, having an average size ranging from 0.1 to 100 .mu.m, each particle consisting of nanocrystalline grains having an average size of 3 to 100 nm or having a nano-layered structure with a layer spacing of 3 to 100 nm. Some of these particles have clusters of metal D attached thereto, with an average size ranging from 2 to 200 nm.

Abstract: A nickel-metal hydride storage battery having a high capacity and excellent cycle life is disclosed. The battery employs, as its material for the negative electrode, a hydrogen storage alloy powder having a composition represented by the general formula Zr.sub.1-x M3.sub.x Mn.sub.a Mo.sub.b Cr.sub.c M1.sub.d M2.sub.e Ni.sub.f, where M1 represents at least one element selected from the group consisting of V, Nb and rare earth elements, M2 represents at least one element selected from the group consisting of Fe, Co and Cu, and M3 represents at least one element selected from the group consisting of Ti and Hf, and where 0.ltoreq.x.ltoreq.0.3, 0.3.ltoreq.a.ltoreq.0.7, 0.01.ltoreq.b.ltoreq.0.2, 0.05.ltoreq.c.ltoreq.0.3, 0.ltoreq.d.ltoreq.0.1, 0.ltoreq.e.ltoreq.0.2, 0.8.ltoreq.f.ltoreq.1.3, and 1.6.ltoreq.a+b+c+d+e+f.ltoreq.2.2, and wherein said hydrogen storage alloy has at least one of a Laves phase having a crystal structure of the MgCu.sub.2 -type (C15) and a Laves phase having a crystal structure of the MgZn.

Abstract: A hydrogen-absorbing alloy which is excellent in stability in an aqueous solution and in mechanical pulverizability is disclosed. This hydrogen-absorbing alloy contains an alloy represented by the following general formula (I):Mg.sub.2 M1.sub.y (I)wherein M1 is at least one element selected (excluding Mg, elements which are capable of causing an exothermic reaction with hydrogen, Al and B) from elements which are incapable of causing an exothermic reaction with hydrogen; and y is defined as 1<y.ltoreq.1.5.

Abstract: There is provided a hydrogen occluding alloy exhibiting high absorption and desorption speeds. A hydrogen occluding alloy comprising as an overall composition: 25 to 45 weight % Zr+Hf, wherein the Hf comprises not more than 4%, 1 to 12 weight % Ti, 10 to 20 weight % Mn, 2 to 12 weight % V, 0.6 to 5 weight % rare earth elements, and a balance Ni (of which content is not less than 25 weight %) and unavoidable impurities, and basically having a three-phase structure consisting of: a main phase which constitutes the matrix of the alloy and which is made of a Zr--Ni--Mn based alloy, a dispersed granular phase made of a rare earth elements--Ni type alloy distributed along the grain boundary of the main phase, and a flaky phase which is made of a Ni--Zr type alloy attached to the dispersed granular phase and intermittently distributed along the grain boundary mentioned above.

Abstract: A cathode of sufficiently low hydrogen overvoltage is provided which is useful in electrolysis of water or of an aqueous alkali metal chloride solution such as a sodium chloride solution. A process for producing the cathode is also provided. The low hydrogen overvoltage cathode has an electroconductive base material coated with an alloy layer containing nickel and molybdenum, the alloy layer containing the nickel at a content ranging from 35 to 90% by weight and the molybdenum at a content ranging from 10 to 65% by weight. The alloy laser has an X-ray diffraction (CuK.alpha. line) pattern with a main peak at an angle ranging from 42 to 45.degree. with a peak half width ranging from 0.4 to 7.degree.. One process for producing the low hydrogen overvoltage cathode of the present invention involves plating an electroconductive base material by an arc discharge type ion plating method.