JPS58163150A - Dry cell - Google Patents

Abstract

PURPOSE:To obtain a thin dry-cell having an increased battery capacity by constituting a separator member from a specific porous film. CONSTITUTION:A separator 10 for intercepting the contact between the positive mix electrode black 1 and a zinc can 3 in a cylindrical dry cell is constituted of a continuous porous film 100 having the three-dimensional structure and the porosity of the film is 50-60%, and the diameter of the opening is 1.0mu or less. Said film 100 has the hole construction having the hole diameter gradually increasing from a thick layer 100A to a porous layer 100B. The thick layer 100A and the porous layer 100B are incorporated into the dry cell described in the above so as to constitute the positive electrode black mix 1 side and the paste layer 11 side respectively. Owing to its specific hole structure, the film 100 described in the above represents the superior ion transmissivity, and effectively prevents migration of the mix 1 in minute particle form into a Zn can 3 through the film 100, when the thick layer 100A is brought into contact with the positive electrode black mix 1.

Description

[Detailed description of the invention] This invention relates to a dry cell with an improved separator.

In LeClancier type dry cell batteries, kraft paper is used as a separator between the zinc can and the anode mixture, but this kraft paper is not strong enough, so it has to be made quite thick, which reduces battery capacity. cause it to happen.

The present invention aims to provide a dry battery using a separator with a new structure that contributes to an increase in battery capacity and can be made thinner and stronger.One embodiment of the invention will be described below with reference to the drawings. do.

FIG. 1 shows a cylindrical dry battery, in which a cathode terminal plate 4 is brought into contact with the bottom of a zinc can 8 containing an anode mixture 1, carbon rods 2, etc., and a metal It is fastened by the lower end curled portion 6a of the outer can 6. The opening of the zinc can 3 is closed by the sealing body 7, the upper end bent part 8a of the resin tube 8 that covers the zinc can 3, and the cathode terminal plate 9, and is tightened by the upper end curled part 6bl of the outer can 6. It is worn.

Reference numeral 10 denotes a separator that cuts off contact between the zinc can 3 and the anode mixture 1, and is provided on the inner wall surface of the zinc can 3 via a glue layer 11, as shown in FIG.

As shown in FIG. 3, the separator 10 is made of a continuous porous film 100 that has a three-dimensional skeleton, and its porosity is 50 to 80% and the pore diameter is 1.0%.
It is less than μ. Further, this film 100 has a dense layer 100A with a very small pore diameter on the negative side and a porous layer 100B with a large pore diameter on the other side, so that the pore diameter changes continuously along the thickness direction a. In other words, the dense layer is 100A
The porous layer 100B has a pore structure in which the pore diameter gradually increases. The dense layer 100A is incorporated into the battery so as to be on the anode mixture 1 side, and the porous layer 100B is on the glue layer 11 side.

A typical example of the continuous porous film 100 is a regenerated cellulose film made of cellulose acetate. That is, such a porous film 100 is produced by, for example, dissolving cellulose acetate in a suitable organic solvent, casting it onto a releasable substrate, and then pouring it into water to replace the solvent with water, and finally drying it. It can be made by forming it into a film and then saponifying it with caustic soda to regenerate it into cellulose. A similar porous film 100 can be formed using materials other than cellulose, that is, various resins.

As is clear from the above configuration, the dry battery of the present invention is
Since a continuous porous film 100 having a three-dimensional skeleton is used as the separator 1o instead of conventional kraft paper, this film 100 exhibits superior strength compared to conventional kraft paper, such as 100P. Even if the front and rear parts are thin, they can withstand use, and this makes it possible to increase the internal capacity of the battery.

In addition, the film 100 exhibits excellent ion permeability due to its seven unique pore structure, while its dense layer 100A
By bringing the side into contact with the anode mixture 1, it is possible to effectively prevent the particulate mixture 1 from migrating to the zinc can 3 through the film 100.

Moreover, since the other surface side is the porous layer 100B with a large pore diameter, the work of assembling the film 100 into the battery container is a hassle. That is, when assembling a battery, a method is usually adopted in which a glue layer 11 is provided on the separator 10 and this is placed inside the zinc can 3, but in this case, the surface on which the glue layer 11 is provided is the dense layer 100A side of the film 10p. There is a problem that the glue layer does not stick well because the surface is too smooth. On the other hand, in the case of the porous layer 100B having a large pore diameter, the problem described in item 1 does not occur, and the glue layer formation and filling operations can be carried out smoothly from beginning to end.

In addition, in FIG. 1, 12 is a bottom plate provided on the bottom of the inner wall of the zinc can 3, and this bottom plate 12 is also connected to the zinc can 3 and the anode mixture l.
Therefore, this bottom plate 12 also functions as a separator to prevent contact with the separator 1.
It can be configured similarly to o.

As described in detail above, the present invention can provide a dry battery that is advantageous in terms of battery capacity and other aspects by configuring the separator member with a specific porous film.

[Brief explanation of drawings]

FIG. 1 is a half-cut section showing an example of a dry battery of the present invention, FIG. 2 is an enlarged view of the part ■ in FIG. 1, and FIG. 3 is an explanatory diagram showing the hole structure of the separator member of the present invention. . l... Anode mixture, 3... Zinc can, 1o... Separator, 100... Continuous porous film, 100A.
... Dense layer, 100B... Porous layer.

Claims (1)

[Claims] +11 The separator interposed between the zinc can and the anode mixture is a continuous porous film that has a three-dimensional skeleton and whose pore diameter increases from the dense layer on one side to the porous layer on the other side. 1. A dry battery characterized in that the dense layer side is interposed so as to be in contact with an anode mixture.