JPS58163145A - Button-shaped cell - Google Patents

Abstract

PURPOSE:To improve the liquid-leakproofness by using a regenerated cellulose film which is made of cellulose acetate serving as its raw material and composed of the continuous porous substance having the three-dimensional structure, as an electrolyte absorbing substance, in substitution for nonwoven fabric in this former use. CONSTITUTION:An electrolyte absorbing substance 3 interposed between a negative electrode 2 and a separator 4, which makes contact with a positive electrode 1 and is composed of a graft-polymerized film layer 4A, cellophane 4B, and a graft-polymerized film layer 4C is composed of a regenerated cellulose film 30 which is made of cellulose acetate serving as its raw material and composed of the continuous porous substance having the three-dimensional structure. Therefore, the battery reaction can be carried-out freely from trouble, owing to the superior electrolyte absorbing faculty and the liquid passing performance of the film 30, and napping in the conventional nonwoven fabric can be eliminated, so the liquid-leakproofness can be improved markedly.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a button type battery having an improved electrolyte absorber.

Conventionally, nonwoven fabrics, vinylon-rayon mixed paper, and the like have been used as electrolyte absorbers, but this ridge absorber has fluff, which has the disadvantage of being susceptible to liquid leakage. That is, as shown in FIG. 4, in a button type battery, the anode 21.degree., the cathode 22.degree. The anode can 25 filled with the electrolyte absorber 23 and the separator 24 and the cathode terminal plate 26 are fitted together via the gasket 27, and the anode can 2
The open end of the can 5 is tightened inward to seal it, but if there are raised hairs 230 along the inner wall surface of the can 25 in the absorbent body 23, these raised hairs 230 exhibit an action similar to capillary phenomenon. Promote swallow liquor of electrolyte from the inner wall surface.

The present invention is mainly aimed at solving the above-mentioned problems. ``Regenerated cellulose, which is a continuous porous material made of cellulose acetate and has a three-dimensional skeleton, is used as an electrolyte absorber instead of the conventional nonwoven fabric. The main point is that film was used.

An example of the button-type battery of the present invention will be described below with reference to the drawings.

In Figures 1 and 2, 1 is an anode made of silver oxide as an active material, appropriately containing a conductive additive such as carbon black or phosphor graphite, and partially impregnated with an alkaline electrolyte; 2 is a cathode made of an active material such as amalgamated bent lead powder, which usually contains a frame material such as sodium polyacrylate, carboxymethyl cellulose, or starch, and is injected with most of an alkaline electrolyte. .

3 is a graft polymerized film layer 4A in contact with the anode 1;
, an electrolyte absorber interposed between the separator 4 and the above-mentioned one pole 2, which is composed of cellophane 4B and a graft polymerized film layer 4C.

5 is the above anode 1. It is an anode can made of nickel-plated iron in which a separator 4 and an electrolyte absorber 3 are filled, and a cathode terminal plate as a cathode electric body in which a cathode 2 is inserted into the opening of the can 5. 6, nylon, polyethylene,
The anode cans 5 are fitted together via an annular gasket 7 made of various resins such as polypropylene or rubber and have a truncated cross section, and the anode can 5 is tightened inward to form a sealed structure inside the battery.

As shown in FIG. 3, the 71-lysis liquid absorber 3 is made of a continuous porous regenerated cellulose film 30 made of cellulose acetate and having a three-dimensional skeleton, and has a porosity of 50 to 50. 80%, and the pore diameter is 1.0μ or less. Such a film 30 can be produced by, for example, dissolving cellulose acetate in a suitable organic solution of Allium, casting it onto a releasable substrate, and then pouring it into water, replacing the solvent L with water, and finally drying it. made into a film,
After that, it can be produced by saponifying it with caustic soda or the like to regenerate it into cellulose.

The cellulose film 30 produced in Production Example A is as follows:
As shown in 3rd fli, there is a dense porous layer 30A with a very small pore size on the - side and a dense porous layer 30B with a pore size on the other side.
It has a pore structure in which the pore diameter changes continuously along the thickness direction 3, such that the porous layer 30B is dense on the separator 4 side, and the porous layer 30A is located on the cathode 2 side.
embedded within the battery.

As is clear from the above structure, the button-type battery of the present invention uses a porous interbiotic cellulose film 30 made of vinegar cellulose as the electrolyte absorber 3; The heavy oil reaction can be carried out without any trouble due to the good electrolyte absorption or liquid passage vjsP, and the leakage resistance is significantly improved since there is no fluffing like in conventional non-woven fabrics.

In addition, because this type of cellulose film 30 has a porous structure, unlike a nonwoven fabric that has a structure in which fibers are simply entangled, this type of cellulose film 30 not only makes it easy to control the thickness of the rib itself, but also reduces stiffness in the battery. In order to set the height of the battery within the standard, the porous structure provides a cushioning effect due to the sponge-like elasticity, which makes it easy to adjust the height. benefits are provided.

Furthermore, the above film 30 is coated with a dense $30A and porous layer 3.
0B and the dense layer 30A side is positioned so as to be in contact with the cathode 2. Therefore, if the migration of the cathode active material toward the anode 1 side is effectively suppressed by the dense layer 30A, .

Note that although silver oxide is used as the anode active material in the above example, other active materials such as manganese dioxide and mercury oxide may also be used. Furthermore, the same effect as described above can be obtained not only in the case of an alkaline battery as shown above, but also in an organic electrolyte battery such as a Li--Mn battery.

Next, in order to clarify the effects of the present invention, a button-shaped alkali having the structure shown in FIGS. The leakage resistance of Aike Pond A was tested in comparison with Comparative Battery B.

The results were as shown below. The test is sample 1
000 batteries were left open for 40 days at 60°C, and the number of batteries that did not show any leakage to the naked eye was determined. Comparative battery B is a battery that uses nonwoven fabric (or vinylon) as the electrolyte absorber.
This battery has the same structure as the example except that rayon mixed paper was used.

Leakage resistance (units) Battery A Q Battery B5 As is clear from the above, the button type battery of the present invention has significantly improved leakage resistance than the conventional one.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an example of a button-type battery of the present invention;
Figure 2 is an enlarged view of the ■ part in Figure 1, Figure 3 is an explanatory diagram of the pore structure of the continuous porous regenerated cellulose film that forms the main part of this invention, and Figure 4 is the conventional button type @ /l. (This is an enlarged sectional view of main parts showing example 2. 1... Anode, 2... Cathode, 3... Electrolyte absorber,
4... Sehalator, 30... 1 m continuous porous Ig cellulose film.

Claims (1)

[Claims] A) The electrolyte absorber interposed between the separator and the cathode in contact with the electrode is composed of a continuous porous regenerated cellulose film with a three-dimensional skeleton made of cellulose acetate. button type battery.