Abstract: The invention provides a hydrogen absorbing alloy electrode obtained by the step P1 of preparing a hydrogen absorbing alloy powder containing cobalt and nickel, the step P2 of subjecting the surfaces of the alloy particles to a reduction treatment with high-temperature hydrogen by holding the powder in a high-temperature hydrogen atmosphere under the conditions of temperature, pressure and time sufficient to reduce oxides formed in a surface layer portion of each of the alloy particles, not melting the alloy particles and not permitting the alloy particles to absorb hydrogen, the step P3 of treating the resulting powder with an acid or alkali by immersing the powder in an acid or alkaline aqueous solution, followed by suction filtration, washing with water and drying, and the step P4 of applying the resulting power to an electrically conductive substrate and shaping the substrate in the form of the electrode. The electrode thus provided has higher activity than conventionally.

Abstract: A hydrogen absorbing alloy electrode is provided which is improved in hydrogen gas absorbing ability and in low-temperature discharge characteristics. The electrode contains a hydrogen absorbing alloy having a crystal structure of the CaCu5 type and represented by the stoichiometric ratio ABx, the hydrogen absorbing alloy being represented by MmNiaCobAlcMd wherein Mm is a misch metal, M is Mn and/or Cu, the atomic ratios a, b, c and d are in the respective ranges of 3.0≦a≦5.2, 0≦b≦1.2, 0.1≦c≦0.9, 0.1≦d≦0.8, wherein X is the sum of the atomic ratios a, b, c, and d, such that, X=a+b+c+d and, is in the range of 4.4≦X≦5.4. More specifically, the electrode contains a hydrogen absorbing alloy powder at least 5.0 in X, and a hydrogen absorbing alloy powder less than 5.0 in X.

Abstract: The invention provides a hydrogen absorbing alloy electrode obtained by the step P1 of preparing a hydrogen absorbing alloy powder containing cobalt and nickel, the step P2 of subjecting the surfaces of the alloy particles to a reduction treatment with high-temperature hydrogen by holding the powder in a high-temperature hydrogen atmosphere under the conditions of temperature, pressure and time sufficient to reduce oxides formed in a surface layer portion of each of the alloy particles, not melting the alloy particles and not permitting the alloy particles to absorb hydrogen, the step P3 of treating the resulting powder with an acid or alkali by immersing the powder in an acid or alkaline aqueous solution, followed by suction filtration, washing with water and drying, and the step P4 of applying the resulting power to an electrically conductive substrate and shaping the substrate in the form of the electrode. The electrode thus provided has higher activity than conventionally.

Abstract: An electrode for the alkaline storage battery according to this invention includes a binding agent containing thermoplastic xylene-formaldehyde resin. Since the thermoplastic xylene-formaldehyde resin is non-aqueous, it will be not dissolved into water in the air or the alkaline electrolyte within the battery. In this case, the removal of the active material during the process of manufacturing the electrode or within the battery can be prevented by any of the techniques of immersing the active-material-applied or -filled electrode substrate in the solution of the thermoplastic xylene-formaldehyde resin dissolved; immersing it in the emulsion of the thermoplastic xylene-formaldehyde resin with an emulsifier; and applying or filling the active material slurry with the emulsion of the thermoplastic xylene-formaldehyde resin to or in the electrode substrate.

Abstract: The method of manufacturing a hydrogen-absorbing alloy electrode comprises: a step of reducing an oxide or hydroxide residing on the surface of a hydrogen-absorbing alloy particle while the alloy particle is held in an atmosphere of a hydrogen gas maintained at a temperature where absorbing of the hydrogen gas does not substantially occur; a step of naturally cooling atmosphere from the temperature where absorbing of the hydrogen gas does not substantially occur to the temperature where the equilibrium hydrogen pressure of the hydrogen-absorbing alloy is equal to the hydrogen pressure in the atmosphere of the hydrogen gas and thereafter vacuum-evacuating the atmosphere of the hydrogen gas so that the hydrogen-absorbing alloy particle is cooled to room temperature while the hydrogen gas is exhausted; a step of exhausting the hydrogen gas and cooling the atmosphere to room temperature and thereafter introducing at least one kind of gas selected from the group consisting of argon, nitrogen and carbon dioxide int

Abstract: The method of manufacturing a hydrogen-absorbing alloy electrode according to this invention comprises the steps of: dissolving a particle surface of said hydrogen-absorbing alloy by a surface-treatment solution; and washing the hydrogen-absorbing alloy with the particle surface dissolved using an alkaline solution at a temperature of 30° C.˜40° C. The metal ions dissolved by the surface-treatment solution can be completely washed away by the alkaline solution so that they will not be precipitated onto the surface of the hydrogen-absorbing alloy again as the hydroxide. In this case, the washing using the alkaline solution of which the temperature exceeds 40° C. dissolves an alloy component as well as the hydroxide. Therefore, the temperature of the alkaline solution used must be controlled at 40° C. or lower. On the other hand, if the temperature of the alkaline solution is lower than 30° C.

Abstract: In a pasted hydrogen-absorbing alloy electrode of this invention, an active material layer made from a mixture of a hydrogen-absorbing alloy powder, a composite particle powder including carbon particles and a rare earth compound for partially coating surfaces of the carbon particles, and a binder is formed on a current collector. When this pasted hydrogen-absorbing alloy electrode is used in an alkaline storage battery, the alkaline storage battery can attain small increase of the internal pressure during charge, large discharge capacity in high rate discharge and good charge-discharge cycle performance.

Abstract: A hydrogen absorbing alloy electrode characterized in that the electrode consists mainly of a mixture of a first hydrogen absorbing alloy powder A formed on surfaces of particles thereof with a surface layer 22 containing metallic copper or a copper oxide and a second hydrogen absorbing alloy powder B formed on surfaces of particles thereof with a surface layer 24 containing metallic cobalt or a cobalt oxide. The copper-coated hydrogen absorbing alloy powder A affords improved electric conductivity, and the cobalt-coated hydrogen absorbing alloy powder B gives improved ability to absorb and desorb hydrogen, whereby the electrode is improved in different battery characteristics, such as cycle characteristics, high-rate discharge characteristics and infernal pressure characteristics, at the same time.

Abstract: A hydrogen storage alloy electrode for a battery is made of a hydrogen storage alloy powder which includes agglomerates of hydrogen storage alloy particles joined together through a metallic layer. A method of making the electrode includes forming agglomerates of hydrogen storage alloy particles joined together by a metallic layer which covers surface portions of the particles, and then forming the electrode using a resulting powder including the agglomerates.

Abstract: An object of the present invention is to provide an effective hydrogen-absorbing alloy activation process which can enhance the electrochemical activity of a hydrogen-absorbing alloy and to provide a hydrogen-absorbing alloy electrode which, when used in a battery, ensures an excellent initial inner pressure characteristic, low-temperature discharge characteristic, high-rate discharge characteristic and cycle characteristic. In accordance with the present invention, a hydrogen-absorbing alloy electrode production process is provided which comprises an alloy activation treatment step of immersing a hydrogen-absorbing alloy in a strong acid treatment solution containing metal ions and, in the course of the pH rise of the acid treatment solution, adding an alkali to the acid treatment solution to promote the pH rise of the acid treatment solution.

Abstract: A hydrogen-absorbing alloy electrode for an alkaline secondary battery. The electrode is prepared by adding a transition metal salt to a paste comprising a hydrogen-absorbing alloy powder and binder. The electrode improves charge-discharge cycle performance and high rate discharge capacity at low temperature of an alkaline secondary battery.

Abstract: The invention provides a hydrogen absorbing alloy electrode obtained by the step P1 of preparing a hydrogen absorbing alloy powder containing cobalt and nickel, the step P2 of subjecting the surfaces of the alloy particles to a reduction treatment with high-temperature hydrogen by holding the powder in a high-temperature hydrogen atmosphere under the conditions of temperature, pressure and time sufficient to reduce oxides formed in a surface layer portion of each of the alloy particles, not melting the alloy particles and not permitting the alloy particles to absorb hydrogen, the step P3 of treating the resulting powder with an acid or alkali by immersing the powder in an acid or alkaline aqueous solution, followed by suction filtration, washing with water and drying, and the step P4 of applying the resulting power to an electrically conductive substrate and shaping the substrate in the form of the electrode. The electrode thus provided has higher activity than conventionally.

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: 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: 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: A hydrogen absorbing alloy electrode contains an alloy which comprises particles A of a first hydrogen absorbing alloy and particles B of a second hydrogen absorbing alloy of a composition different from the composition of the first alloy joined to the particles A, with a joint layer C formed at the resulting joint interfaces and having a new composition containing the component elements of the first and second alloys. In a specific embodiment, particles A of a first hydrogen absorbing alloy having a CaCu.sub.5 -type structure are joined to particles B of a second hydrogen absorbing alloy having a Zr--Ni Laves-phase structure. In another embodiment, particles A of a first hydrogen absorbing alloy having a CaCu.sub.5 -type structure are joined to particles B of a second hydrogen absorbing alloy having a CaCu.sub.5 -type structure and different form the first alloy in composition.

Abstract: In a heat exchanger according to the present invention, there are provided a filling container having a first containing section containing a hydrogen-absorbing metal material for middle or high temperature, a second containing section containing a hydrogen-absorbing metal material for low temperature which is higher in equilibrium hydrogen pressure at the same temperature than the hydrogen-absorbing metal material for middle or high temperature, and a hydrogen passage for moving hydrogen between the first containing section and the second containing section; a guiding section having a heating section provided with heating means for heating the filling container, a heat radiating section provided with a heat exchanging section for radiating heat generated in the filling container outward, and a heat absorbing section provided with a heat exchanging section for cooling the outside by absorption of heat in the filling container; and moving means for moving the filling container back and forth in the guiding sec

Abstract: The invention relates to an apparatus for measuring the gas absorbing and/or desorbing characteristics of a substance having a property to absorb a gas. The apparatus comprises a sample container for containing the substance, a gas storage connected to the sample container for storing the gas until a predetermined pressure is reached, a gas supply source for supplying the gas to the gas storage, a first valve provided on a line connecting the gas supply source to the gas storage, a second valve provided on the line between the first valve and the gas storage, and a third valve provided on a gas discharge line connected to the line between the first and second valves, the first to third valves being each a two-position valve having an open position and a closed position, the valves defining a region thereby surrounded and serving as a preliminary storage for temporarily holding the gas when the gas is supplied or discharged.

Abstract: A heat transfer system comprising a hydrogen supply unit 1, which transfers hydrogen from a hydrogen recovery tube 8 to a hydrogen supply tube 7, and a multiplicity of hydrogen utilization units 2A and 2B which utilize hydrogen supplied from the hydrogen supply tube 7 via its branching tubes 7a and 7b, respectively, and return hydrogen to the hydrogen recovery tube 8 via associated branching tubes 8a and 8b. By the use of the hydrogen supply tube 7 and the hydrogen recovery tube 8 having large volumetric capacities and filled with hydrogen, the hydrogen supply unit 1 and the hydrogen utilization units 2A and 2B may operate independently, without being synchronized one other.