Deutsche Automobilgesellschaft Mbh

Deutsche Automobilgesellschaft

Daimler-benz Ag

Firma Deutsche Automobilgesellschaft Mbh

Deutsche Automobilgesellshaft Mbh

Deutsche Automobilgesellschaft Mbh, Firma

Gabor Benczur-Urmossy

Klaus Von Benda

Gerhard Berger

Friedrich Haschka

Holger Kistrup

Rainer Klink

Claus Schneider

Gunter Gutmann

Ute Baumeyer

Uwe Gierz

An aqueous cadmium oxide paste of high flowability for the vibration filling of foam-structure and fiber-structure electrode plaques is characterized by a cadmium oxide content of about 25 to 35% by volume, a pH of about 10 to 12.5, a content of about 0.5 to 2.5% by weight, based on cadmium oxide, of one or more dispersants from the group comprising the water-soluble salts of polyphosphoric acids, di- and polyphosphonic acids and their derivatives, gluconic acid or of antimonyl tartrate. The paste has a plastic viscosity of about 0.1 to 1 Pa.s and also a yield value of between about 10 and 120 Pa. This cadmium oxide paste makes it possible to fill foam-structure and fiber-structure electrode plaques completely in one operation.

Vibration filling of foam-structure and fiber-structure electrode

Aqueous cadmium oxide paste of high flowability for the vibration

An alkaline nickel-cadmium storage battery in which the active material with which the negative electrode is filled with, or the electrolyte in the storage battery, contains polyvinylpyrrolidone as an expander. Polyvinylpyrrolidone compounds having a mean molecular weight of 5,000 to 35,000 g/mol have proved particularly advantageous.

Nickel-cadmium storage battery with improved electrical properties

A nickel-cadmium storage battery with improved electrical properties is described in which one or more copolymers of vinyl pyrrolidone is/are added as expander to the active material with which the negative electrode is filled or to the electrolyte. The polymers have a mean molecular weight of 10,000 g/mol to 100,000 g/mol, with a vinyl pyrrolidone content of between 5 and 95 mol-%. The copolymers are added to the active material or to the electrolyte in an amount of 0.1 to 1.0% by weight, based on the active material. As a result of adding the copolymers, a malfunction-free operation of the storage battery is achieved, accompanied by a simultaneously equally as good degree of utilization of the cadmium active material compared with a storage battery which contains homopolymeric polyvinyl pyrrolidone.

Nickel-cadium storage battery with improved electrical properties

A paste for vibration filling of foam-structure or fiber-structure electrode plates for galvanic cells, particularly for electrical accumulators, said paste having an active substance content of about 25 to 60 percent by volume, a maximum active particle size of about 0.04 mm and in an unvibrated state a yield value of approximately 10 to 120 Pa and a plastic viscosity of about 1.0 to 1.0 Pas at 20.degree. C. The paste is preferably set in vibration with a frequency of about 40 to 125 Hz and an amplitude of about 0.1 to 1.5 mm by a vibration transmitter fitted inside a tank containing the paste.

Paste for the vibration filling of foam-structure and fiber-structure

A method for the vibration filling of foam-structure or fiber-structure electrode plaques for galvanic cells, particularly for electrical accumulators, totally immerses one or more electrode plaques in a vibrating paste of active mass which has an active mass content of about 25 to 60 vol %, a maximum granulometry of the active particles of about 0.04 mm and in the unvibrated state a yield value of about 10 to 120 Pa and a plastic viscosity of about 0.1 to 1 Pas at 20.degree. C. The paste is preferably set in vibration with a frequency of about 40 to 125 Hz and an amplitude of about 0.1 to 1.5 mm by a vibration transmitter fitted inside the tank containing the paste.

Method for the vibration filling of foam-structue and fiber-structure

An aqueous nickel-hydroxide paste of high flowability for the vibration filling of foam-structure and fiber-structure electrode plaques has a content of about 30 to 50% by volume of nickel hydroxide, a maximum particle size of about 0.04 mm, a plastic viscosity of about 0.1 to 1 Pa.s and a yield value of between about 10 and 120 Pa, a pH of between about 9 and 12 and a content of about 0.5 to 5, in particular about 1 to 5, % by weight, based on the nickel hydroxide content, of a dispersant from the group comprising the water-soluble salts of polhphosphoric acids or di- and polyphosphonic acids and their derivatives. Very particularly suitable as a dispersant is 1-hydroxyethane-1, 1-diphosphonic acid in the form of its cobalt/alkali salt complex. This paste makes it possible to completely fill foam-structure and fiber-structure electrode plaques in one operation.

Aqueous nickel hydroxide paste of high flowability

A gas tightly sealed nickel-cadmium cell is provided which works on the oxygen cycle principle and has a charge and discharge reserve at the negative electrode. Further, the partial pressure of the gases which cannot be reacted in the cell is below 0.4 bar. As a result of this substantial removal of the gases which cannot be reacted from the interior space of the cell, there is a considerable rise in the oxygen consumption rate, i.e., the rate at which the oxygen generated in the cell is reacted at the negative electrode, so that higher charge current densities are possible.

Nickel-cadmium cell apparatus

The invention relates to a process for the chemical metallization of sheetlike textile substrates, in particular, of non-woven or needle felt webs, in which the substrates are activated and subsequently electrolessly metallized in a reductant-containing metallization solution in a horizontal attitude or at an angle of up to 20.degree. with the horizontal. The hydrogen which appears as a by-product in the course of the metallization can, as a result, escape particularly simply and rapidly from the substrate, so that uniform metallization of the fibers of the substrate can take place across the entire thickness of the substrate.

Process for electroless metallization of sheetlike textile substrates

Electrode structures made from metallized bodies of a fibrous nature, for example from metallized felt, possess the advantage, deriving from their intrinsic stiffness, of requiring no internally fitted supporting structure. It is, however, difficult to attach the current lead-out tabs to an electrode structure of this type, because it is hightly susceptible to mechanical damage at the point of attachment. These difficulties are avoided, according to the present invention, when the edge of the electrode structure is reinforced, to a width of about 0.3 to about 1 cm, by means of an electrodeposited metal coating. If appropriate, the reinforcement of the edge can also be carried out simultaneously with the production, by electrodeposition, of the electrode structure. The current lead out-tab can be attached to the reinforced edge avoiding such difficulties.

Process for producing a stable connection between an electrode structure

A hydrogen electrode for batteries or galvanic cells in which a first section of the electrode has relatively large pores and serves for the transport of hydrogen and a second section with relatively small pores containing Raney-nickel catalyst. According to the invention, the electrode consists of a metallized fibrous substrate, for example a felt of carbon or textile fibers, with relatively large intrinsic porosity. The Raney-nickel is introduced into this felt from the outside by one of a variety of methods, for example immersion in a vibrating powder bed, by suction of a liquid suspension of Raney-nickel powder or by the application of a paste containing Raney-nickel or a starting alloy therefor. Preferably, the fibrous substrate consists of a number of layers having a preferred fiber orientation, in which at least one of the layers is so turned that the orientation of the fibers is different from that of the surrounding layers, thereby impeding the penetration of Raney-nickel during the manufacture and constituting a zone free from Raney-nickel and of high porosity to serve as a transport layer for hydrogen. A number of examples is presented.

Bi-porous Raney-nickel electrode

The heat transfer in a nickel-oxide/hydrogen battery cell is substantially improved by increasing the thermal conductivity in the axial direction of the electrode stack. This improvement in thermal conductivity is due principally to the construction of the negative electrode containing catalyst as an integral part of the gas diffusion element, thus reducing the number of components in an electrode unit of the battery stack from six to four.

Nickel-oxide/hydrogen battery cells

Electrodes for galvanic elements which contain an active mass and an electrocatalyst, an organic binding agent and a conductive substance which also contributes simultaneously to the mechanical rigidity; as conductive substance is used the voluminous material obtained by thermal decomposition of nickel- or/and iron-carbonyl in the presence of an inert gas that is not preheated.

Electrodes for galvanic elements

A rechargeable galvanic cell has a housing containing at least one negative zinc electrode, at least one positive metal oxide or oxygen electrode, an alkaline electrolyte, at least one electrically conductive auxiliary structure exhibiting low hydrogen overvoltage, for cathodic hydrogen evolution which is not conductively connected with the electrodes, and at least one microporous separator for separating said auxiliary structure from at least one of said electrodes. The structure simultaneously acts as an auxiliary electrode to effect afterdischarging of the zinc electrode when connected thereto and as a dendrite barrier to prevent short-circuiting between the negative and positive electrodes during operation of said cell and is arranged between one positive electrode and one negative electrode.

Growing community of inventors

Stuttgart, Germany

Gabor Benczur-Urmossy