Showing papers on "Hydrogen storage published in 1985"

Rechargeable battery and electrode used therein

Abstract: An improved battery utilizing a hydrogen rechargeable anode of a disordered non-equilibrium multicomponent material including one or more elements forming a host matrix and at least one modifier element incorporated therein. The anode is capable of electrochemically absorbing hydrogen from an electrolyte during application of a charging current thereto. The hydrogen is stored in the anode bulk until discharge is initiated, whereupon an electrical current is produced when the hydrogen is released. The superior battery of the invention has attained high density energy storage, efficient reversibility, high electrical efficiency, bulk hydrogen storage without structural change or poisoning and hence long cycle life and deep discharge capability.

Hydrogen storage materials and methods of sizing and preparing the same for electrochemical applications

Abstract: The present invention provides novel active materials (15,40,115) which reversibly store hydrogen under conditions which make them exceptionally well-suited for electrochemical applications. These active materials have both novel compositions and structures. A first group of active material compositions incorporate the elements of titanium, vanadium, and nickel. A second group adds zirconium to the first group of active materials. A preferred third composition group adds chromium to the first group of active materials. These materials may be single or multi- phase combinations of amorphous, microcrystalline, or polycrystalline structures. Preferably, these materials have a multiphase polycrystalline structure. Methods of reducing the size or of sizing these materials, as well as other hydride-forming alloys, also are provided. Methods of preparing the inventive hydrogen storage materials and fabricating electrodes (15,40,115) from these active materials are contemplated. Electrochemical cells (10,100) and batteries assembled with the inventive electrodes provide significantly improved capacity and cycle life.

Preparation and properties of hydrogen storage alloy-copper microcapsules

Abstract: Fine particles of hydrogen storage alloys such as LaNi5 and MmNi4.5-Mn0.5 (Mm  misch metal) were encapsulated in a thin layer of copper 1–2 μm thick by means of a special chemical plating method. This treatment prevented further disintegration of the metal and improved the thermal conductivity. The alloy-copper microcapsules, which had dimensions of less than 30 μm, were able to absorb hydrogen easily without special activation and exhibited no decrease in hydrogen storage capacity. Pellets obtained by compressing the microencapsulated powder under a pressure of 5–10 tf cm−2 did not show any visible cracks after 1000 hydrogen sorption cycles.

Amorphous metal alloy compositions for reversible hydrogen storage

Abstract: Novel materials having the ability to reversibly store hydrogen are amorphous metal alloys of the formula A.sub.a M.sub.b M'.sub.c wherein A is at least one metal selected from the group consisting of Ag, Au, Hg, Pd and Pt; M is at least one metal selected from the group consisting of Pb, Ru, Cu, Cr, Mo, Si, W, Ni, Al, Sn, Co, Fe, Zn, Cd, Ga and Mn; and M' is at least one metal selected from the group consisting of Ca, Mg, Ti, Y, Zr, Hf, Nb, V, Ta and the rare earths; and wherein a ranges from greater than zero to about 0.80; b ranges from zero to about 0.70; and c ranges from about 0.08 to about 0.95; characterized in that (1) a substantial portion of A is disposed on the surface of said material and/or (2) that said material functions as an active surface layer for adsorbing/desorbing hydrogen in conjunction with a bulk storage material comprising a reversible hydrogen storage material.

Method for adsorbing and storing hydrogen at cryogenic temperatures

Abstract: Hydrogen is stored at cryogenic temperatures by adsorption on porous carbon having a nitrogen BET apparent surface area above about 1500 m 2 /g. Hydrogen can be adsorbed and desorbed in the context of a cryopump, having as the pumping element a panel, having large particles of pressed porous carbon thereon.

Hydriding mechanism of Mg2Ni in the presence of oxygen impurity in hydrogen

Abstract: For the case where oxygen is present as an impurity in hydrogen, a hydriding mechanism is proposed along with hydriding cycling of the Mg2Ni alloy. The large chemical affinity of magnesium for oxygen leads to the selective oxidation of magnesium and to the segregation of the more noble nickel component. The consequence is a progressive decrease in hydrogen storage capacity of Mg2Ni along with hydriding cycling. The segregated nickel provides active sites for chemisorption of oxygen and hydrogen. The chemisorbed oxygen accelerates the surface segregation of nickel or can form water vapour with hydrogen, or (least favourably) directly oxidizes nickel. The chemisorbed hydrogen can form water vapour with oxygen, can hydride Mg2Ni or can reduce the nickel oxide eventually formed. All these reactions are exothermic, causing an increase in temperature during the hydriding process.

Hydrogen storage cell

Abstract: The purpose of this invention is to store hydrogen in the form of a metal hydride. The hydride is disposed on the surface of a plurality of metal fins which are attached to heat transfer tubes. The fins are closely spaced so that the weight of hydrogen stored per unit volume is high, approaching one pound per cubic foot. Because the formation of a metal hydride is quite exothermic, the rate of addition or removal of hydrogen to or from the hydride is limited by the ability of the apparatus to conduct heat to or from the hydride. The structure of the present invention provides for rapid heat transfer, so that the cell can be used in a heat pump, a hydrogen compressor, or to store hydrogen fuel for a vehicle. The invention includes embodiments wherein the heat transfer medium is either a liquid or a gas. The invention also comprises a new method of applying a metal or metal alloy, capable of forming a metal hydride, to a metal surface.

Application of organic compounds to metal-hydrogen systems as a technique for improving sorption properties: A new class of hydrogen absorbers

Abstract: A technique for using organic materials to improve the sorption properties of magnesium-based hydrogen storage media is presented. Two approaches are possible. First, Mg 2 Ni and SmMg 3 reversibly absorb hydrogen under more moderate conditions when they have been modified with various organic compounds (anthracene, phenanthrene, chrysene, perylene, naphthacene, phthalonitrile, tetracyanoethylene or chloranil). The hydriding behaviour of modified Mg 2 Ni and SmMg 3 is associated with the formation of electron donor-acceptor (EDA) complexes by charge transfer between the alloy particles and the organic modifiers. The process of hydrogen uptake is explained by “hydrogen spill-over”, in which hydrogen species in an atomiclike form which have been activated at the EDA sites rapidly migrate to react with the adjoining alloy particles. Second, small solvated magnesium particles formed by clustering in low temperature organic matrices (tetrahydrofuran, benzene, pentane or ethyl ether) are exceptionally active and immediately begin to absorb hydrogen without requiring “activation”. The hydrogen sorption characteristics of these magnesium-organic compound systems are elucidated. The exceptional activity of these systems can be partially interpreted in terms of their structural geometry compared with that of pure magnesium. The organic matrix in which the magnesium atoms are dispersed and in which crystal growth proceeds has pronounced effects on the shape, size and catalytic properties of the particles formed.

Electrochemical Investigation of Hydrogen Storage in Metal Hydrides

Abstract: One of the problems regarding the use of hydrogen as an energy carrier is related to storage. One approach for a solution is related to the use of solid metal hydrides. Many studies regarding the formation of metal hydrides have included the conduction of absorption experiments in which hydrogen from the gas phase reacts with solid alloys. However, electrochemical methods provide another approach for the study of metal hydrides. Thus, measurements can be conducted under isothermal conditions by applying an electrical potential, rather than changing the pressure and/or the temperature. Certain difficulties related to a use of aqueous electrolytes can be avoided by using nonaqueous electrolytes. In the present investigation, NaH dissolved in a low temperature molten salt is used as the electrolyte. The hydrogen transmitting species in this case are not H(+) ions, but H(-) ions. A new theoretical approach is also discussed and applied, together with the considered experimental method, to three systems. These systems include Mg-Ni-H, Mg-Cu-H, and Mg-Al-H. 29 references.

Sealed metal oxide-hydrogen storage cell

Abstract: Disclosed is a method of producing a sealed metal oxide-hydrogen storage cell, comprising the step of housing in a container a cathode containing a metal oxide as an active material, an anode containing a hydrogen storage alloy as the main component, a separator for separating the cathode and the anode, a pre-charging member, and an electrolyte solution consisting of an alkaline aqueous solution. The pre-charging member is electrically combined with the anode and consists of a metal having a less noble potential than the hydrogen electrode potential within the alkaline solution. A material containing said metal as the main component may also be used as the pre-charging member. The storage cell has a desired anode-cathode capacity balance and exhibits a long life.

Hydrides of ZrMn2-based alloys substoichiometric in zirconium for engineering applications

Abstract: The hydrogen storage characteristics of TiMn 1.5 and Zr 1 − x T x Mn y Fe z ( T ≡ Ti , Mn , Fe ) alloys substoichiometric in zirconium in the range ..., with manganese sites on ZrMn 2 lattice substituted by iron such that y + z = 1, were studied. Pressure-composition isotherms and other thermodynamic data are presented. All the host alloys and their hydrides exhibit a C14 (MgZn 2 ) structure. The hydrogen capacity of the alloys is large and the hydrides have very favorable dissociation pressures. The work computed for the hydrogen charging and discharging of the Zr 1 − x T x Mn y Fe z alloys was observed to be lower than that for TiMn 1.5 and other accepted hydrogen storage materials. Utilization of the Zr 1 − x T x Mn y Fe z alloys in a hydrogen-powered automobile and in a heat pump or refrigerator appears to have distinct advantages.

The crystallographic, thermodynamic and kinetic properties of the Zr1−xTixCrFeH2 system

Abstract: The Zr 1− x Ti x CrFeH 2 system has been studied at various temperatures and in the pressure range up to 70 atm with x = 0 – 0.7. These intermetallics absorb copious amounts of hydrogen, the hydrogen densities relative to that of liquid hydrogen being 1.41 and 1.25 for Zr 0.7 Ti 0.3 CrFe and Zr 0.5 Ti 0.5 CrFe respectively. The pressure-composition isotherms exhibit a favorable dissociation pressure around 1 atm at room temperature. The enthalpies for the desorption process range from 24.3 to 36.1 kJ (mol H 2 ) −1 , depending on the x value. The entropy changes are almost constant with a value of 99.1 ± 1 J K −1 (mol H 2 ) −1 . The kinetics of the hydrogen sorption are rapid, being nearly complete in a few minutes. These results suggest that this material is a desirable candidate for hydrogen storage.

Metallic hydride hydrogen storage for balloon inflation

Abstract: A low weight, small total volume, high volumetric capacity hydrogen storage system, as for the high altitude inflation of balloons launched from rockets, comprises a solid unitary matrix of an endothermically decomposable metallic hydride, such as magnesium hydride, enclosed within a spherical containment shell. The matrix has a plurality of uniformly distributed holes therein into each of which is inserted a high specific energy chemical heat source which reacts to provide exothermic energy to decompose the hydride. The chemical heat sources, which preferably comprise intermetallics, are disposed within ceramic tubes received in the holes along with an electrically operated reaction initiator for the chemical heat source. An electrical actuator is disposed on the exterior of the containment shell for actuating the reaction initiators.

System for exchange of hydrogen between liquid and solid phases

Abstract: The reversible reaction M+x/2 H 2 ←→MH x , wherein M is a reversible metal hydride former that forms a hydride MH x in the presence of H 2 , generally used to store and recall H 2 , is found to proceed under an inert liquid, thereby reducing contamination, providing better temperature control, providing in situ mobility of the reactants, and increasing flexibility in process design. Thus, a slurry of particles of a metal hydride former with an inert solvent is subjected to a temperature and pressure controlled atmosphere containing H 2 , to store hydrogen and to release previously stored hydrogen. The direction of the flow of the H 2 through the liquid is dependent upon the H 2 pressure in the gas phase at a given temperature. When the actual H 2 pressure is above the equilibrium absorption pressure of the respective hydride the reaction proceeds to the right, i.e., the metal hydride is formed and hydrogen is stored in the solid particles. When the actual pressure in the gas phase is below the equilibrium dissociation pressure of the respective hydride the reaction proceeds to the left, the metal hydride is decomposed and hydrogen is released into the gas phase.

Hydrogen storage in some ternary and quaternary zirconium-based alloys with the C14 structure

Abstract: The Zr0.8Ti0.2MnCr1.25, ZrMnFeTx (T ≡ Cr, Ni, Co; 0 < x < 0.4) and ZrCrFe1 + x (0 < x < 0.5) alloys were studied for their hydrogen storage characteristics in the temperature range 23–150°C and hydrogen equilibrium pressure (0.01–50 atm). The kinetics of hydrogen sorption by these alloys are observed to be extremely rapid, and the processes are almost complete in 60–200 s. Hydrogen capacities of these alloys are in the range 92–222 cm3 H2 (g alloy)−1. The hyperstoichiometric elements appear to substitute at the zirconium site in these AB2-type alloys with a net effect of raising the decomposition pressure of their hydrides several-fold over that of the ZrMn2 and ZrCr2 hydrides. The ZrMnFeCo0.4 alloy does not absorb measurable quantities of hydrogen, presumably because of the high decomposition pressure of its hypothetical hydride. The effectiveness of alloying elements in destabilizing the ZrMn2 hydride increases in the following order: Cr < Mn < Fe < Ni < Co. It is found that, unlike ZrMn2, ZrCr2 cannot be made hyperstoichiometric with chromium or manganese. The hydrides of ZrCrFe1 + x alloys have very favorable dissociation pressures, e.g. 0.9–2 atm at room temperature. The enthalpies and entropies of dehydrogenation of their hydrides are in the range 20–23 kJ (mol H2)−1 and 66–80 J mol−1 K−1 respectively, which are advantageous for application purposes.

Metal hydride storage container and process for its manufacture

Abstract: The invention relates to a metal hydride in the form of a cylindrical pressure vessel with a centrally disposed filter tube as a gas guide tube, wherein the granulated hydrogenatable metal melt by partition plates having a central opening, unterteilt1st in the axial direction into slices. In order to meet the object of forming a metal hydride so as to have the largest possible hydrogen storage capacity at a given pressure vessel volume and its production is cost-effective, it is proposed that the baffle plates prior to the first loading of the metal hydride with hydrogen, in each case, the upper (15) and form the lower part (10) of a box (5), that the volume of completely with the hydrogenatable metal melt (8) at least by the amount is backfilled doses (5) in the sum over the net internal volume of the pressure vessel (1) is smaller that the specific increase in volume the molten metal used in each case (8) in the hydrated state after repeated loading and unloading with respect to the originally unloaded state corresponds.

Fuel cell power generation type hot water supplier for space cooling and heating

Abstract: PURPOSE:To make it possible to perform power generation and hot water supply for space cooling and heating by a single energy source of a fuel gas by separating hydrogen occluded in a hydrogen storage alloy to supply the same to the fuel cell power generating device in an emergency in which a hydrogen gas is impossible to obtain from a reformer. CONSTITUTION:In a case where a natural gas 10 becomes impossible to be supplied, a contact 43 is opened and a contact 48 is closed and an emergency power is supplied from a battery 46. Then, the opening degree of a pressure reducing valve 22 is adjusted to reduce the pressure within a hydrogen preserving device 18 to a predetermined value or less and to separate hydrogen from a hydrogen storage alloy. Then, a hydrogen gas is fed to a fuel cell power generating device 14. In a case where the quantity of the hydrogen gas passing through a pipeline 18G is insufficient even when the pressure reducing valve 22 is fully opened, valves 26VA and 16VB are closed but valves 26VC and 16VD are opened, and a contact 42A is closed. As a result, a heat exchanger 40 for heating is heated, and a circulation pump 42 is turned ON. The interior of the hydrogen preserving device 18 is heated, and the hydrogen separation speed becomes large. Thus, the quantity of the hydrogen gas supplied to the fuel cell power generating device is increased.

Catalytic metal hydride space heater

Abstract: An apparatus for heating air wherein the combustion is dispersed in direct proximity to a metal hydride fuel storage means in order that the combustion heat effects the release of hydrogen from the metal hydride. The combustion area contains a catalyst and a semipermeable membrane separates the hydride fuel storage means and the combustion area. The temperature of the metal hydride is raised to effect initial release of hydrogen which passes through the semipermeable membrane, mixes with air and is combusted at the catalyst. The heat of combustion, in direct proximity to the metal hydride, perpetuates the hydrogen release.

Manufacture of sealed nickel-hydrogen storage battery

Abstract: PURPOSE:To prevent decrease in cycle life caused by repearting charge-discharge by using an electrode obtained by forming a thin electrolytic oxidation film on the surface of hydrogen occlusion alloy as a negative electrode of sealed nickel-hydrogen storage battery. CONSTITUTION:Hydrogen occlusion alloy powder is applied to both sides of a porous metal or filled in a porous metal to form an electrode plate, then the plate is anodically polarized in alkaline solution, then washed and dried to form a negative electrode. This electrode is stable and its dissolution into alkaline electrolyte is prevented and change of alloy composition and short circuit are decreased even after repeating charge-discharge. Decrease in capacity after storage caused by decrease in activity of the surface of negative electrode is also suppressed.

Calcium-nickel-misch metal-aluminum quaternary alloy for hydrogen storage

Abstract: A calcium-nickel-misch metal-aluminum quaternary alloy for hydrogen storage having an enhanced hydrogen absorbing/releasing capability which allows for the selection of equilibrium pressures for metal hydride formation and dissociation over a broad temperature range. The alloy has the formula: CaNia Mmb Alc, wherein Mm is a misch metal; a, b and c are, respectively, atomic ratios of Ni, Mm and Al, with Ca taken as unity; and 5-(b+c)

Zirconium-manganese-iron alloys

Abstract: Hydrogen storage materials are provided of a ternary alloy of the formula: ZrMnFex wherein x has a value from 12 to 13, and their hydrides