DE1267736B - Depolarizer press body - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY DEUTSCHES '/ MTWWSt PATENTAMT

EDITORIAL

Int. Cl .:

HOIm

German KL: 21b -7/01

Number:
File number:
Registration date:
Display day:

P 12 67 736.0-45
June 15, 1960
May 9, 1968

The present invention relates to a depolarizer press body for galvanic dry batteries with high electrical energy output.

The main patent 1139167 is a galvanic Dry battery with a depolarizer pressed body made of finely divided metal oxides and finely divided carbon and a binder described as a cathode, the binder consisting of portland cement. The amount of cement is between 5 and 20 percent by weight. Galvanic dry batteries of this type allow a current draw at high voltages and low resistance via a long service life.

In order to achieve these properties, i. H. a high load per unit volume of active material, yet To further improve it, it is desirable to use electrodes with large surface areas. It appears therefore it is expedient to manufacture the electrodes in the form of thin plates.

Thin plate electrodes have been used by the industry for both primary and primary uses for a number of years Secondary elements used. The constructions used, however, are difficult and expensive manufacture and tend to be fragile when handled, e.g. B. built into the cell will. Furthermore, these designs are often limited to specific types of depolarizers.

It is known to use an inorganic binder for fixing a particulate depolarizer use. It is also known, a grid made of expanded metal as a carrier for an electrochemical to use reactive electrode material. However, it is not known to have a depolarization mixture of the composition described in the main patent to be embedded in a thin lattice of expanded metal. Only the combination of these features enables depolarization compacts of very small thickness and maintain excellent strength.

The invention relates to a galvanic dry battery with a finely divided metal oxides, finely divided carbon and portland cement as a binder as a cathode according to patent 1139 167. The battery is characterized in that the depolarization compact is embedded in a thin mesh made of expanded metal. Preferably the cathode has one Thickness from 0.56 to 0.8 mm.

The electrodes according to the invention are constructed so that the desired cathode mixture adhesively applied to an expanded expanded metal mesh of the desired dimensions. These Measure enables thin plate electrodes to be made into depolarizer compacts

Addendum to the patent: 1139 167

Applicant:

Union Carbide Corporation,
New York, NY (V. St. A.)

Representative:

Dipl.-Ing. H. Görtz, patent attorney,
6000 Frankfurt, Schneckenhofstr. 27

Named as inventor:
Lewis Frederick Urry,
Parma, Ohio (V. St. A.)

Claimed priority:

V. St. v. America dated June 16, 1959 (820 722)

which are exceptionally strong and flexible and rough handling without tearing, Resist loosening or disintegration. The electrodes also allow a more efficient one Use of a depolarizer than was previously possible. The metal grid serves as a carrier for the cathode mixture and also as an electrical conductor. By using the expanded metal mesh becomes considerable ensures better conductivity than the usual sieve that is often used for this purpose Metal wires can be achieved. The reason for this is that the overlapping wire formation of the Sieves often become loose during handling. Lack of contact between the loosened wires gets but increased contact resistance. Often there is also a loss of mixture.

The choice of metal for the grid varies with the desired cathode polarizer, electrolyte, metal the solution electrode as well as the ultimate application of the battery. The metal should be such which does not react with the depolarizer and does not form undesirable products. For example, you can Iron, nickel or nickel-plated copper with manganese dioxide, mercury oxide, nickel oxide or Use mixtures of these depolarizers. copper

809 548/157

alone cannot be used, as it is all mentioned Depolarizers is anodic and forms soluble reaction products with them. Silver-coated Copper can be used for primary cells with a short service life, in which a silver oxide depolar is provided. Where a standing time is accepted after activation, however, it is necessary, entirely To use grids made of silver, as there are pinholes in the silver layer on a copper grid Lead to oxidation of the copper and cause a discharge of the silver oxide.

The mesh size of the grid depends on the desired thickness of the finished electrode and the previous discharge conditions. The thickness of the grid varies with the mesh size, so a thin electrode requires a fine grid. For electrodes 0.56 to 0.8 mm thick it was Found expedient to use expanded metal mesh with a thickness between 0.46 and 0.51 mm.

Plate cathodes according to the present invention can be, for. B. for manganese dioxide-zinc or Use mercury oxide — zinc. The rechargeability of different cell systems is greatly improved by using the new plate design been. The application used for the silver oxide production of compacts, which the dimensions 7.4 9.2 cm and their thickness ranged between 0.58 and 0.64 mm. When finished Electrode, the grid was embedded in the active particles.

Example 2

Weight percent

Mixed depolarizer (50 percent by volume HgO and MnO ₂ ) 68.8

Graphite 8.0

Steel wool 2.85

Cement (Portland) 6.05

0.5 normal KOH solution 14.30

100.00

16 g of a mixture was used with an expanded metal mesh made of nickel (7.4 9.2 cm).

Example 3

Ag ₂ O

Cement (portland)

Steel wool

Weight percent 93.3

100.0

Zinc system allows a substantial reduction in the
Manufacturing costs compared to the currently used 17 g of this mixture were converted into an expanded metal

technical process. This type of cathode grid made of copper (7.4 9.2 cm) was introduced. The training also allows the use of whole was moistened by spraying with a 0.5 normal divalent silver oxide in a depolarizer 30 KOH solution and then with a pressure mixture. A powerful use of this compressed ^{by 4200 kg / cm 2.} The material obtained was previously not possible. Plate had a thickness of 0.76 mm.

In general, the amount of electrochemically active material used is between 50 and 90 percent by weight of the powdered mixture in which the grid is embedded.

example

Weight percent

HgO (red or yellow) 85.62

Finely divided graphite 8.56

Steel wool 2.05

Cement (Portland) 3.77

100.00

Half of the required amount per compact was put into the (dry) mold. The nickel-plated expanded copper metal cathode lead was placed on top and coated with the remainder of the dry mixture. After spraying the mixture with 0.5 normal KOH solution to moisture, the mold was closed and the compact was pressed at 4200 kg / cm ² . The excess liquid was squeezed out. About 17 g of dry mixture per compact was used for

Claims (2)

Patent claims: 1. Galvanic dry battery with one made of finely divided metal oxides, finely divided carbon and portland cement as the binder, the existing depolarizer compacts as the cathode according to patent 1139 167, characterized in that that the depolarizer pressed body is embedded in a thin lattice of expanded metal is. 2. Dry battery according to claim 1, characterized in that the cathode has a thickness of 0.56-0.8 mm. Considered publications: German Patent Nos. 40 629, 110 210, 241, 225 728, 460 090, 500 277; German interpretative document No. 1 052 490; Austrian patent specifications No. 30,922, 118 369 g French patent specifications No. 548 892, 1 093 651; British Patent Nos. 754194, 792 464; U.S. Patent No. 2,656,402. 809 548/157 4.68 © Bundesdruckerei Berlin