DK144449B - BATTERY CONSISTING OF OVEN STANDING CELLS - Google Patents

Description

(19) DENMARK i || (m) (12) PUBLICATION (s)

DIRECTORATE OF THE PATENT AND TRADEMARKET SYSTEM

(21) Application No. 5318/78 (51) | nt.CI.3 Η 01 Μ 2/02 (22) Filing date 28 November. 1978 (24) Running day 28 Nov. 1978 (41) Aim. available 29 · May 1980 (44) Submitted Mar 8 1982 (86) International application no. - (86) International filing day - (85) Transfer day - (62) Master application no. - (30) Priority - (71) Applicant A / S HELLESENS, 2860 Søborg, DK.

(72) Invented Per Jan Thorbjørn Jensen, DK.

(74) Associate Company Chas. Hude.

(54) Battery consisting of superimposed cells.

BACKGROUND OF THE INVENTION 1. Field of the Invention The invention relates to a battery consisting of a single flat cell or multiple superimposed cells integrally connected along the perimeter, each cell having a zinc anode, an alkaline electrolyte, a mercury oxide, silver oxide or ternary cathode or a mixture thereof and a cell enclosure. in the form of a plastic bowl, in which both inside and outside the bottom of each bowl is arranged a terminal plate which abuts a substantial CQ area of the outer and inner surface of the bottom, at least the one terminal plate having at least one protruding knob which extends rf * -fig through a relatively small hole in the bottom of the bowl and is thus connected to the second terminal plate - preferably by spot welding - that the plates clamp about and under pressure abut the material in the bowl bottom which is of or in-Q corporates elastomeric material.

2 144449

From the specification of German Patent No. 906,586 there is known a battery block of flat cells, the active parts of which are arranged in frames of non-curable thermoplastic material, a plate of said thermoplastic material being made at the bottom of each frame. conductive by the addition of carbon, and the plate abuts against a zinc plate, which is guided from the underlying cell by a relatively large bulged portion through a similarly shaped recess in the bottom of the frame. By adhering the zinc plate in each cell to the frame using a solvent for it, a relatively good security against electrolyte penetration to the conductive thermoplastic plate is obtained. However, this known construction is not sufficient to solve the sealing problems that occur with alkaline batteries of the kind in question.

In the case of alkaline batteries of the aforementioned type with cells stacked on top of each other, it has been a problem to obtain a sufficiently close assembly of the cells into an integrated unit. This problem is now solved by the fact that a special method is used for assembling the dishes around their periphery, in which the dishes are at one time joined around the entire circumference by a rapid process.

It is an object of the present invention to provide additional safety against electrolyte leakage from an alkaline battery of the kind in question by increasing the resistance to electrolyte leakage at the terminal penetration at the bottom of each plastic bowl.

Usually, electrolyte leakage from an alkaline battery is due to one or more of the following well-known phenomena: 1. Capillary action in surface irregularities, poor seal, etc.

2. Electrocapillary action.

3. Oxygen reduction.

4. i ^ O reduction.

5. Electrosmosis.

6. Marangoni effects.

In addition to the conditions mentioned, terminal amalgamation usually also plays a role, since the zinc electrodes contain mercury, which will be distributed between zinc and terminal metal. This is important in the negative terminal, where the phenomena mentioned in points 3-6 only occur and where, in experience, there are also the greatest sealing difficulties.

According to the invention, a battery of the type mentioned initially is characterized in that in the hole at the bottom of each bowl a sealing ring is arranged around the knob projecting from one terminal plate.

At this connection, with a large specific pressure between the terminal metal and the elastomeric material, a permanent seal is obtained, avoiding cold flow which could otherwise give rise to a decreasing pressure between polymer and metal. Furthermore, an intermediate cavity which will break the capillary action is obtained and a long creep path between terminal metal and polymer.

The invention will be explained in more detail below with reference to the drawing, in which 1 shows a terminal insertion in a flat cell battery according to the invention, and FIG. 2 shows an alternative embodiment of the terminal feed-through.

In FIG. 1 shows two plastic bowls 1 forming cell enclosures. The enclosures are interconnected at junction surfaces 2 in a process by which the entire periphery is affected simultaneously. Such an immediate influence can, for example, is produced by ultrasonic welding, gluing, by immersion, heat welding, high frequency welding or the like.

The lower bowl of FIG. 1 contains a pressed cathode 3 of mercury oxide, silver oxide or brownstone or mixtures thereof, two separator layers 4 and an anode 5 consisting of powdered zinc in an alkaline electrolyte. Above cathode 3 there is a negative terminal plate 6 with curved edges and below the anode 5 - at the bottom of the bowl - another terminal plate 7.

Claims (1)

U4449 The terminal plates 6 and 7 in superimposed plastic bowls 1 are interconnected through a hole in the middle of the bottom 8 of the upper bowl, one terminal plate 7 having an embossed projecting knob 9 extending through the hole in the bowl bottom 8 and is spot welded to the center of the second terminal plate 6. The spot weld is designed such that terminal plates 6 and 7 clamp the material at the bottom 8 so as to create a pressure seal between the terminal metals and the material at the bottom which is elastomeric, whereby cold flow and consequent declining system pressure is avoided * As the terminal plates clamp on both sides of the bottom 8, a double seal between the metal and plastic polymer surfaces is obtained under a specific sealing pressure which may be very high over the relatively small sealing area. Further, the terminal plate 6 may optionally consist of a metal which is particularly inhibitory to -reduction and -reduction, etc., thereby providing additional security against leakage. Furthermore, at the arrangement shown, a long electrolyte creep path is obtained. In the embodiment shown in FIG. 1, the knob 9 of the terminal plate 7 is surrounded by a sealing ring 10, e.g. a rubber O-ring which deforms under pressure when the terminal plates are assembled. This provides two additional separate zones between metal and rubber with intermediate air, which breaks the capillary action. In the embodiment of FIG. 2, the plastic bowl is molded from a hard thermoplastic elastomer and the edge of the hole in the bowl bottom 8 is formed with three protruding sealing portions 11 forming three separate intermediate air plastic metal seal zones. The same terminal penetration principle will also be applicable to the top and bottom of a single flat cell. Claims. Battery consisting of a single flat cell or several stacked cells integrally connected along each other.