JPH09274897A - Alkaline button battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an alkaline button type battery, in which an air layer interposed between a separator and a positive electrode is eliminated so as to lower the inner resistance value, by providing a projecting part in a surface, which contacts a separator of a gasket made of resin and having L-shaped cross section. SOLUTION: A bottom part 7a of a gasket 7 made of resin and having an L-shaped cross section, which contacts a separator arranged on a positive electrode of an alkaline button battery, is formed with a projecting part 7b at a width W directed from the center to the peripheral part so that the separator is pushed onto the positive electrode by the projecting part 7b. With this structure, the projecting part 7b eliminates the most of the air of an air layer interposed between the separator and the positive electrode, and with the elapse of time after assembling a battery, inner resistance of the battery can be evenly stabilized low, and an alkaline button battery, of which inner resistance is low, can be obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an alkaline button battery.

[0002]

2. Description of the Related Art An example of a conventional alkaline button battery will be described below.

FIG. 3 is a sectional view of a button type zinc-air battery, which is a type of alkaline button type battery. In the figure, reference numeral 1 denotes a bottomed cylindrical positive electrode case having an air hole 1a opened at the bottom, and an air diffusion paper 2 from the bottom, a microporous membrane 3 made of fluorinated polyethylene 3, a positive electrode 4 mainly composed of manganese oxide. , The separator 5 made of a semi-permeable membrane of cellulose is sequentially accommodated. Reference numeral 6 denotes a negative electrode case, in which a tubular resin gasket 7 having a substantially L-shaped cross section is fitted to the outer peripheral portion, and a negative electrode zinc 8 sufficiently containing an electrolytic solution is filled inside.

The assembly of this type of battery is generally negative zinc 8
The negative electrode side and the positive electrode side are coupled in a direction in which the surface of the positive electrode case and the surface of the separator 5 in the positive electrode case 1 are in contact with each other, and the opening of the positive electrode case 1 is crimped inward by the mold. The resin gasket 7 is sandwiched between the opening of the positive electrode case 1 and the negative electrode case 6, and the button type zinc-air battery is liquid-tightly sealed.

The bending pressure during crimping of the positive electrode case 1 is transmitted in the vertical direction to the outer peripheral portions of the separator 5, the positive electrode 4, and the microporous membrane 3 through the bottom portion 7a of the resin gasket 7, and the above-mentioned components Only the outer circumference is compressed.
Here, at the time of compressing the peripheral parts of the components of the separator 5, the positive electrode 4, and the microporous membrane 3, a slight air layer 9 interposed between the separator 5 and the positive electrode 4 is sealed between the separator 5 and the positive electrode 4,
After the battery is assembled, it hinders the ionic conduction of the electrolytic solution, leading to an increase in the resistance inside the battery.

Therefore, a means for preventing the formation of the air layer 9 is provided by adhering the positive electrode 4 and the separator 5 with, for example, carboxymethyl cellulose which dissolves in an electrolytic solution, which does not impede ion permeation, or the positive electrode is previously formed. After injecting the electrolytic solution into the case 1, the separator 5 is placed and the opening portion of the positive electrode case 1 is crimped to ensure the ion conductivity of the electrolytic solution between the positive electrode case 1 and the negative electrode case 6. Conceivable.

[0007]

However, in the means for bringing the positive electrode 4 and the separator 5 into close contact with each other with an adhesive, the adhesive impedes the ion permeability of the positive electrode 4 and the separator 5, and the battery is disposed by the adhesive arranging means. There is a problem that solids that increase the internal resistance are generated during the production of the battery, and in the case of a means for sealing the positive electrode 4 after injecting the electrolytic solution in advance,
There is a problem that the electrolytic solution may scatter when the electrolytic solution is injected, and the battery and the assembly line may be contaminated.

[0008]

In order to solve the above problems, the alkaline button battery of the present invention is a positive electrode case, which is a bottom portion of a tubular gasket interposed between a positive electrode case and a negative electrode case. On the surface in contact with the separator arranged on the surface, using a gasket having a convex or concave groove from the center of the battery toward the outer periphery is used, the separator and the positive electrode of the presence of the convex or concave groove. The amount of air in the air layer interposed between them almost disappears.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to claim 1 is a bottomed cylinder in which zinc serving as a negative electrode active material and an alkaline electrolyte are filled and a cylindrical resin gasket having an L-shaped cross section is fitted to the outer peripheral portion. In the alkaline button battery having the above negative electrode case, in the resin gasket, a surface in contact with the separator disposed on the positive electrode surface, a convex portion is formed from the central portion toward the outer peripheral portion, Due to this convex portion, the amount of air in the air layer interposed between the separator and the positive electrode almost disappears, so that the internal resistance of the battery decreases as time passes after the battery is assembled.

The invention according to claim 2 is such that the size of the convex portion is 0.1 to 0.2 mm in height and 0.1 to 0.5 mm in width. In addition to the function, the electrolytic solution does not leak out of the battery even when the convex portion is formed.

Further, according to a third aspect of the present invention, zinc having a negative electrode active material and an alkaline electrolyte are filled, and a cylindrical resin gasket having a L-shaped cross section and fitted with a resin gasket is fitted to the outer peripheral portion. An alkaline button battery including a negative electrode case, wherein in the resin gasket, a recess groove extending from a central portion toward an outer peripheral portion is formed on a surface in contact with a separator arranged on a positive electrode surface. The groove almost eliminates the amount of air in the air layer interposed between the separator and the positive electrode, so that the internal resistance of the battery decreases as time passes after the battery is assembled.

According to a fourth aspect of the present invention, the size of the concave groove is 0.1 to 0.25 mm in depth and 0.3 to 1.0 mm in width.
By virtue of this, in addition to the effect of the invention according to claim 3, the electrolytic solution does not leak to the outside of the battery even when the recessed groove is formed.

[0013]

Embodiments of the present invention will be described below. The same components as those of the conventional example shown in FIG.
Detailed description is omitted.

(Embodiment 1) Hereinafter, Embodiment 1 of the present invention will be described with reference to FIG.

In FIG. 1, the resin gasket 7 is formed by forming a convex portion 7b extending from the central portion toward the outer peripheral portion on the surface of the bottom portion 7a in contact with the separator 5 arranged on the positive electrode 4 in FIG.

As shown in Table 1, four isosceles triangular prism-shaped projections 7b are formed on the resin gasket 7, and the height h of each projection 7b is set to 0.15 mm.
Zinc-air batteries were prepared by changing the width w of the base of the above, and the respective batteries were designated as sample batteries A to E.

[0017]

[Table 1]

Further, as a conventional example, an air zinc battery was prepared in the same manner as in Example 1 except that a gasket having a uniformly smooth surface in contact with the separator 5 arranged on the surface of the positive electrode 4 was used. Was used as a comparative battery S.

Twenty batteries A to E were prepared under the same conditions as the normal products, and the internal resistance of each battery was measured immediately after assembling as a battery, and after 24 hours at 20 ° C. for 4 hours.
The changes with time after 8 hours, 72 hours, 96 hours, and 120 hours were investigated. The results obtained in this experiment are shown in Table 2.

[0020]

[Table 2]

The numerical values in Table 2 are the average battery internal resistance values of 20 of each of the sample batteries A to E after a certain period of time. By forming a convex portion 7b on the surface of the resin gasket 7 that contacts the separator 5 arranged on the surface of the positive electrode 4, it was confirmed that the internal resistance of the battery decreases with time from the value immediately after the battery is assembled. Was done. Further, the effect does not tend to be due to the change in the width w of the base of the convex portion, and the internal resistance values are uniformly stabilized in the sample batteries A to E.
Here, in order to confirm the effect of the present invention, each sample battery after the above-described test was disassembled and the state of the air layer 9 was observed. As a result, it was confirmed that the comparative battery S still had the air layer 9. In the batteries A to E, which are the examples of the present invention, the amount of air in the air layer 9 almost disappeared although there were some differences depending on the respective sample batteries. The effect of the present invention can be confirmed by considering the experimental results obtained in consideration of the fact that the presence of the air layer 9 was uniformly confirmed in each battery in the disassembly investigation immediately after the assembly of the sample batteries A to E.

(Embodiment 2) Next, as shown in Table 3, a convex portion 7b having an isosceles triangular prism shape is formed on the bottom portion 7a of the resin gasket 7.
Are formed in four places, the width w of the base of each convex portion 7b is set to 0.5 mm, and the height h of the convex portion is changed to make an air zinc battery.
Or I. Sample batteries F to I as in Example 1
About 20 pieces of each internal resistance were prepared under the same conditions as the normal product, immediately after assembly, after storage for 24 hours at 20 ° C, after 48 hours, after 72 hours, after 96 hours, after 120 hours. The change with time after storage was investigated. The results obtained in this experiment are shown in Table 4.

[0023]

[Table 3]

[0024]

[Table 4]

The numerical values in Table 4 are the average battery internal resistance values of 20 of each of the sample batteries F to I after a fixed time. It has been confirmed that by forming the convex portion 7b on the resin gasket 7, the internal resistance of the battery decreases from the value immediately after assembly with the lapse of time. Further, it was confirmed that the effect becomes larger as the height h of the convex portion increases when the width w of the base portion of the convex portion 7b is constant at 0.5 mm. Note that S
Is a comparative battery in which the bottom portion 7a of the resin gasket 7 is not provided with a convex portion, and the internal resistance value of the battery hardly decreases even after 120 hours immediately after assembly.
It can be understood that there is little change immediately after assembly and after the passage of time.

(Third Embodiment) A button type air battery according to a third embodiment of the present invention has a convex portion 7b formed on a resin gasket 7.
In the battery configuration, the separator 5 and the outer peripheral portion of the positive electrode 4 form a portion where the pressure is partially loose, and as a result,
A part where the tight contact between the positive electrode 4 and the positive electrode case 1 is weak is formed. Since there is a concern that the electrolytic solution may pass through that portion and eventually flow out from the air holes 1a, the sample batteries A to I used in Example 1 and Example 2 had a temperature of 45 ° C.
Conducting a constant resistance discharge test in a humid environment with a humidity of 70%,
An outflow phenomenon of the electrolytic solution from the air holes 1a due to the discharge was observed. The results obtained in this experiment are shown in Table 5.

[0027]

[Table 5]

The numerical values in Table 5 show the electrolytic solution outflow phenomenon when observing each air hole 1a after constant resistance discharge of five sample batteries A to I under a humid environment at 45 ° C. and a humidity of 70%. It is the incidence. The height h of the convex portion 7b is 0.2 mm
It was found that if the width exceeds 0.5 mm and the width exceeds 0.5 mm, the electrolytic solution may flow out from the air hole 1a. From these results, the size of the convex portion 7b formed on the resin gasket has a height h of 0.1 to 0.2 mm and a base width w of 0.
Forming in the range of 1 to 0.5 mm makes it possible to obtain a button type zinc-air battery in which the internal resistance value of the battery is uniformly low and stable, and there is no risk of the electrolyte flowing out from the air hole 1a. .

(Fourth Embodiment) A fourth embodiment of the present invention will be described below with reference to FIG.

In FIG. 2, the resin gasket 7 has a recessed groove 7d extending from the central portion to the outer peripheral portion on the surface of the bottom portion 7c in contact with the separator 5 arranged on the positive electrode 4 in FIG.
Is formed. As shown in Table 6, four recessed grooves 7d having an isosceles triangular cross section are formed in the resin gasket 7, and the depth m of each recessed groove 7d is set to 0.15 mm, and the width of the base of the recessed groove 7d is set. Zinc-air batteries were prepared by changing the size of w, and the respective batteries were designated as sample batteries J to N.

[0031]

[Table 6]

Further, as a conventional example, an air zinc battery similar to that of Example 4 of the present invention was prepared except that a gasket having a uniformly smooth surface in contact with the separator 5 arranged on the surface of the positive electrode 4 was used. This was used as a comparative battery S.

Twenty batteries J to N were prepared under the same conditions as the normal products, and the internal resistance of each battery was measured immediately after assembling as a battery, and after 24 hours at 20 ° C. for 4 hours.
The changes with time after 8 hours, 72 hours, 96 hours, and 120 hours were investigated. The results obtained in this experiment are shown in Table 7.

[0034]

[Table 7]

The numerical values in Table 7 are the average internal resistance values of 20 battery cells of each of the sample batteries J to N after a fixed time. By forming the recessed groove 7d on the surface of the resin gasket 7 that contacts the separator 5 arranged on the surface of the positive electrode 4, that is, the bottom portion 7c, the internal resistance of the battery decreases from the value immediately after the battery is assembled with the passage of time. It was confirmed to do. It was also found that the effect tends to increase as the width w of the base of the recessed groove 7d increases. Here, in order to confirm the effect of the present invention, each sample battery after the above test was disassembled and the state of the air layer 9 was observed, and it was confirmed that the air layer 9 still existed in the comparative battery S. In the sample batteries J to N, which are the examples of the present invention, the air amount in the air layer 9 almost disappeared although there were some differences between the sample batteries. In the disassembly survey immediately after the assembly of the sample batteries J to N, the air layer 9 was uniformly applied to each sample battery.
Considering the existence of the above, the effect of Example 4 of the present invention can be confirmed by considering the obtained experimental results.

(Embodiment 5) Next, as shown in Table 8, four recessed grooves 7d having an isosceles triangular cross section are formed in the bottom portion 7c of the resin gasket 7, and the width w of the base of each recessed groove 7d is formed. Each of the sample batteries was designated as O to R by making the size of 0.5 mm different and changing the size of the depth m of the recessed groove 7d. Similar to the fourth embodiment, 20 sample batteries O to R were prepared under the same conditions as the normal production product, and the internal resistance of each sample was immediately after assembly at 20 ° C.
Under 24 hours, after 48 hours storage, after 72 hours storage,
After the storage for 96 hours and the storage for 120 hours, the change with time was investigated. The results obtained in that experiment are shown in Table 9.

[0037]

[Table 8]

[0038]

[Table 9]

The numerical values in Table 9 are the average battery internal resistances of 20 of each of the sample batteries O to R after the elapse of a predetermined time. By forming the recessed groove 7d in the bottom portion 7c of the resin gasket 7, the internal resistance of the battery can be changed from the value immediately after assembly to
It was confirmed that it decreased over time. It was also confirmed that the effect is that when the width w of the base of the concave groove 7d is constant at 0.5 mm, the deeper the depth m of the concave groove 7d, the greater the tendency. In addition, S is a comparative battery in which a recessed groove is not provided in the bottom of the resin gasket 7, and the internal resistance value of the battery hardly decreases even after 120 hours immediately after assembly. It can be understood that there is little change immediately after and after the passage of time.

(Embodiment 6) In the button type air battery according to Embodiment 6, when the recessed groove 7d of the bottom portion 7c formed in the resin gasket 7 has a battery structure, the pressure contact between the separator 5 and the outer peripheral portion of the positive electrode 4 is partially caused. A loose portion is formed, and as a result, a portion where the positive electrode 4 and the positive electrode case 1 are partially weakly adhered to each other is formed. It is feared that the electrolytic solution may pass through the portion and finally flow out from the air hole 1a. Regarding sample batteries J to R used in Examples 4 and 5 45
A constant resistance discharge test was performed in a humid environment at a temperature of 70 ° C. and a humidity of 70%, and the phenomenon of the outflow of the electrolytic solution from the air holes 1a due to the discharge was observed. The results obtained in this experiment are shown in Table 10.

[0041]

[Table 10]

The numerical values in Table 10 show the electrolytic solution outflow phenomenon when observing each air hole 1a after constant resistance discharge of five sample batteries J to R under constant humidity discharge at 45 ° C. and 70% humidity. It is the incidence.

It has been found that when the width w of the base of the recessed groove 7d exceeds 1.0 mm, the electrolytic solution may flow out from the air hole 1a. From these results, the size of the concave groove 7d formed in the bottom portion 7c of the resin gasket 7 has a depth m of 0.
1 to 0.25 mm, width 0.3 to 1.0 mm
It is possible to obtain a button type zinc-air battery in which the internal resistance value of the battery is uniformly low and stable, and there is no risk of the electrolyte flowing out from the air hole 1a.

[0044]

As described above, in the button-type alkaline battery of the present invention, in the gasket, the surface in contact with the separator disposed on the positive electrode surface has the convex portion or the concave portion formed from the central portion toward the outer peripheral portion. By using
The internal resistance value of the battery can be made uniformly low and stable.

[Brief description of drawings]

FIG. 1A is a sectional view of a gasket used in the zinc-air battery shown in Examples 1 to 3 of the present invention. FIG. 1B is a bottom view of the gasket.

FIG. 2A is a sectional view of a gasket used in the zinc-air battery shown in Examples 4 to 6 of the present invention. FIG. 2B is a bottom view of the gasket.

FIG. 3 is a side sectional view showing a conventional zinc-air battery.

[Explanation of symbols]

 1 Positive electrode case 1a Air hole 4 Positive electrode 5 Separator 6 Negative electrode case 7 Resin gasket 7a, 7c Bottom part 7b Convex part 7d Recessed groove 8 Negative zinc 9 Air layer w Base width h Height m Depth

Continued Front Page (72) Inventor Jiro Okamoto 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd.

Claims (4)

[Claims] 1. An alkaline button battery comprising a bottomed cylindrical negative electrode case, which is filled with zinc serving as a negative electrode active material and an alkaline electrolyte and has a cylindrical resin gasket having an L-shaped cross section fitted to the outer peripheral portion. In the above resin gasket, an alkaline button battery in which a convex portion extending from a central portion toward an outer peripheral portion is formed on a surface of the resin gasket which is in contact with the separator arranged on the positive electrode surface. 2. The alkaline button-type battery according to claim 1, wherein the protrusions formed on the resin gasket have a height of 0.1 to 0.2 mm and a width of 0.1 to 0.5 mm. 3. An alkaline button battery provided with a bottomed cylindrical negative electrode case in which zinc serving as a negative electrode active material and an alkaline electrolyte are filled and a cylindrical resin gasket having an L-shaped cross section is fitted to the outer peripheral portion. In the above resin gasket, an alkaline button battery in which a concave groove extending from the central portion toward the outer peripheral portion is formed on a surface of the resin gasket which is in contact with the separator arranged on the positive electrode surface. 4. The size of the recessed groove formed in the gasket has a depth of 0.1 to 0.25 mm and a width of 0.3 to 1.0.
The alkaline button type battery according to claim 3, wherein the size is mm.