Abstract: A shaped body of hydrogen absorbing alloy prepared by pressing a mixture of a hydrogen absorbing alloy powder A having a first particle-size distribution, a hydrogen absorbing alloy powder B having a second particle-size distribution and a binder C. The powder A is larger than the powder B in mean particle size. The mixture has a mean particle size ratio r.sub.B /r.sub.A of the powder B to the powder A, wherein r.sub.A and r.sub.B are the mean particle sizes of the respective powders A and B of at least 0.03 to not greater than 0.50. The hydrogen absorbing alloy of the powder B has a higher rate of progress of pulverization resulting from absorption and desorption of hydrogen than the hydrogen absorbing alloy of the powder A.

Abstract: A hydrogen-absorbing alloy electrode for metal hydride alkaline batteries uses as hydrogen-absorbing material a powder of a rare earth element-nickel hydrogen-absorbing alloy obtained by pulverizing thin strips of said alloy prepared by single roll process and having an average thickness of 0.08 to 0.35 mm and a minimum size of crystal grains present in the roll-surface size of at least 0.2 .mu.m and a maximum size of crystal grains in the open-surface side of not more than 20 .mu.m. A process for producing the above electrode is also provided. The electrode can provide, when used as negative electrode, metal hydride alkaline batteries which are excellent in both high-rate discharge characteristics at an initial period of charge-discharge cycles and charge-discharge cycle characteristics.

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: The plateau region of P-C-T isotherm of a hydrogen absorbing alloy between the .alpha. phase region and .beta. phase region thereof is expressed by a normal cumulative distribution function wherein hydrogen content X is taken as frequency and the logarithm of equilibrium hydrogen pressure as a random variable. Parameters such as standard deviation .sigma. of the function are determined by numerical analysis based on measured data as to the equilibrium hydrogen pressure and hydrogen content of the plateau region of the alloy to be evaluated. Whether the equilibrium characteristics of the alloy are acceptable is determined using the parameters as evaluation criteria.

Abstract: A hydrogen absorbing alloy represented by the general formula R.sub.1-x A.sub.x (Ni.sub.5-y B.sub.y).sub.z wherein R is Mm (misch metal) or La, A is at least one element selected from the group consisting of Ce, Nd, Pr, Sm and Y, B is at least one element selected from the group consisting of Al, Sn, V, Cr, Mn, Fe, Co and Cu, 0.ltoreq.x.ltoreq.0.5, 0<y.ltoreq.1.0 and 0.8.ltoreq.z.ltoreq.1.2. The alloy is prepared by subjecting an alloy material of the above composition to a heat treatment so that when the plateau region of the resulting hydrogen absorbing alloy is expressed by a normal cumulative distribution function wherein the hydrogen content of the alloy is taken as frequency and the logarithm of the equilibrium hydrogen pressure of the alloy as a random variable, the alloy is at least 0.04 to up to 0.10 in standard deviation .sigma..

Abstract: Three types of novel hydrogen-absorbing alloy electrodes A, B and C usable for metal hydride secondary batteries are provided. All three types are represented by the general formula AB.sub.x wherein A represents Ti or elements that principally comprise Ti and generate heat upon absorption of hydrogen, B represents Mo and Ni or elements that principally comprise Mo and Ni and absorb heat upon absorption of hydrogen and 0.5.ltoreq.X.ltoreq.2, and are readily producible and difficult to undergo cycle deterioration and need only short activation treatment time. (A) uses a hydrogen-absorbing alloy obtained by quenching and solidifying an alloy melt under an atmosphere of a reducing gas containing hydrogen at a cooling rate of at least 1.times.10.sup.3 .degree. C.

Abstract: A fuel cell system for directly converting chemical energy of a fuel into electric energy electrochemically. A fuel cell has a cathode and an anode. A main hydrogen absorbing alloy supplies hydrogen gas to the anode of the fuel cell during steady-state operation of the system. An auxiliary hydrogen absorbing alloy originally having a higher hydrogen gas absorbing/desorbing equilibrium pressure than the main hydrogen absorbing alloy at an equal temperature supplies hydrogen gas to the anode until the equilibrium pressure of the main hydrogen absorbing alloy, which is supplied an exhaust gas from the fuel cell is equal to a hydrogen gas absorbing/desorbing equilibrium pressure of the auxiliary hydrogen absorbing alloy, the auxiliary hydrogen absorbing alloy receiving the hydrogen gas from the main hydrogen absorbing alloy during steady-state operation.

Abstract: A hydrogen absorbing alloy having a crystal structure of CaCu.sub.5 -type hexagonal system and represented by the general formula Re.sub.1-x Y.sub.x (Ni.sub.5-y G.sub.y).sub.z wherein Re is one of La, Ce, Nd, Pr, misch metal and lanthanum-rich misch metal, Y is yttrium, Ni is nickel, and G is an element capable of forming an intermetallic compound or complete solid solution in corporation with Ni or a mixture of such elements, and x, y and z are in the ranges of 0<x.ltoreq.0.6, 0<y.ltoreq.1 and 0.8<z.ltoreq.1.2, respectively. This alloy has a high equilibrium hydrogen desorbing pressure at room temperature, a great capacity to absorb hydrogen and high durability to repeatedly absorb and desorb hydrogen.

Abstract: Disclosed is a hydrogen-absorbing alloy electrode including a hydrogen-absorbing alloy capable of absorbing and desorbing hydrogen reversibly, the electrode being characterized in that the hydrogen-absorbing alloy forms a multi-phase structure composed of at least these three phases, a main alloy phase, an alloy phase of Ti.sub.2 Ni system cubic-structure and an alloy phase of Ti-Ni system monoclinic-structure, and the main alloy phase has TiMo-based crystalline cubic-structure.

Abstract: A fuel cell system for directly converting chemical energy of a fuel into electric energy electrochemically. A fuel cell has a cathode and an anode. A main hydrogen absorbing alloy supplies a hydrogen gas to the anode of the fuel cell during steady-state operation of the system. An auxiliary hydrogen absorbing alloy originally having a higher hydrogen gas absorbing/desorbing equilibrium pressure than the main hydrogen absorbing alloy at an equal temperature supplies a hydrogen gas to the anode until the equilibrium pressure of the main hydrogen absorbing alloy, which is supplied an exhaust gas from the fuel cell is equal to a hydrogen gas absorbing/desorbing equilibrium pressure of the auxiliary hydrogen absorbing alloy, the auxiliary hydrogen absorbing alloy receiving the hydrogen gas from the main hydrogen absorbing alloy during steady-state operation.

Abstract: In order to make a thermal utilization system operable in a stable and efficient condition regardless the variation of the operating heat source used, the system is provided with three hydrogen absorbing alloys having different pressure-temperature characteristics, wherein absorption/desorption of hydrogen gas is performed in two steps, i.e. the hydrogen gas desorbed from a first alloy is absorbed by a second alloy at a predetermined pressure, and is absorbed by the third alloy at a higher pressure after it is desorbed from the second alloy in a case when the temperature of the operating heat source is low, while the hydrogen gas desorbed from the first alloy is directly transported from the first alloy to the third alloy to be absorbed there when the temperature of the operating heat source is high.

Abstract: Alloys having the composition Zr(Mn.sub.1-x Co.sub.x).sub.y Al.sub.z A.sub.w are formed by adding rare-earth metals such as La, Ce, and Mm and the like or V to a Zr-Mn-Co-Al quaternary alloy, where A is at least one of rare-earth metals such as La, Ce, Mm and the like or V, and the amount x of Co substituent is the range 0<x<0.5; stoichiometric ratio y for (Mn+Co)/Zr, in 1.7<y<2.3; the amount z of Al added, in 0<z<0.15; and the amount w of A added, in 0<w<0.4. The alloys thus formed turn out to be hydrogen absorbing alloys having small absorption-disorption heat difference and long lives, yet maintaining the properties of the quaternary alloy.

Abstract: A refrigerating and/or heating device of the contact type utilizing the endothermic and exothermic reactions of a hydrogen absorbing alloy comprises a contact member (16) in the form of a closed container (18) having a contact surface (17) and packed with a hydrogen absorbing alloy (19), a handle member (21) in the form of a closed container (22) packed with another hydrogen absorbing alloy (23), and a gas pipe (25) interconnecting the two members and having a valve (26).

Abstract: Hydrogen absorbing ZrMn2 alloys having MgZn2-type Laves phase structure with its Mn partially substituted by Co and containing Al as an additive and having the composition Zr(Mn1-=xCox)y Alz;Hydrogen absorbing ZrMn2 alloys having MgZn2-type Laves-phase structure with its Mn partially substituted by Co and Zr partially substituted Zr1-wTiw(Mn1-xCox)y Alz; andHydrogen absorbing alloys formed from ZrMn2 alloy having MgZn2-type Laves-phase structure or from a multicomponent alloy made therefrom by partially substituting the Zr and Mn with some other element, by further adding thereto at least one element or rare earth, Ca, and Mg.

Abstract: A metal hydride container, comprising a heat pipe of annular cross section, a metal hydride filling the central cavity of said heat pipe, closure members serving to close the openings at the opposite ends of said central cavity, a hydrogen passage tube possessed of a shut-off valve and fitted into an aperture formed in one of said closure members and communicated with the cavity of the heat pipe through a partition member pervious to hydrogen gas and impervious to said metal hydride; and a metal hydride heat storage system comprising at least one metal hydride container above-mentioned, which is useful for storing solar heat and waste heat.

Abstract: A metal hydride container, comprising a heat pipe of annular cross section, a metal hydride filling the central cavity of said heat pipe, closure members serving to close the openings at the opposite ends of said central cavity, a hydrogen passage tube possessed of a shut-off valve and fitted into an aperture formed in one of said closure members and communicated with the cavity of the heat pipe through a partition member pervious to hydrogen gas and impervious to said metal hydride; and a metal hydride heat storage system comprising at least one metal hydride container abovementioned, which is useful for storing solar heat and waste heat.