JP5479171B2 - Manufacturing method of flat battery - Google Patents

Description

The present invention relates to a method for producing a flat shape batteries.

  In recent years, small electronic devices such as mobile phones and game machines are often used. Many of the batteries mounted on such small electronic devices have a structure in which a power generation element having an electrolytic solution is incorporated inside the positive electrode can and the negative electrode can, and the positive electrode can and the negative electrode can are caulked through a gasket. . In this flat battery, the problem is that the electrolyte leaks out of the battery. The battery leaked in this way contaminates the inside of the device such as the terminal with the alkaline component of the electrolytic solution, for example, and causes the electric device to malfunction.

  For this problem, it has been studied to apply and seal a sealing material on the surface of the gasket (for example, Patent Document 1).

JP 2000-353505 A

  However, even if the sealing material is applied to the surface of the gasket, the liquid leakage is not completely eliminated. The present invention has been made in view of such circumstances, and its purpose is to keep the electrolyte leaking to the outside of the gasket on the gasket surface, and the electrolyte stains the terminals and the like inside the electronic device. This is to prevent breakdown of electronic equipment.

The present invention provides the following means in order to solve the above problems .

A flat battery manufacturing method according to the present invention includes a step of enclosing a power generation element inside an inner container and an outer container, a step of caulking the inner container and the outer container via a fitting member, and fitting from the inner container surface. It consists of the process of apply | coating a silicone resin to a compound member, the process of drying and solidifying the said silicone resin, and the process of removing the said silicone resin of a terminal contact part, It is characterized by the above-mentioned.
According to the present invention, when the silicone resin is applied to the exposed portion of the negative electrode can, the electrolyte component (for example, an alkaline component in an alkaline battery) that has been scooped up due to leakage can be retained between the silicone resin and the negative electrode can. it can. Therefore, even when leakage occurs in the battery, it is possible to minimize equipment failure due to the electrolyte component (alkali component).

Furthermore, the flat battery manufacturing method according to the present invention is characterized in that the silicone resin has an alkyl group .
According to the present invention, the alkyl group in the silicone resin is disposed on the outermost surface of the coating agent, thereby preventing moisture from entering and preventing leakage from proceeding.
Instrument failure can be minimized.
Furthermore, the flat battery manufacturing method according to the present invention is characterized in that the inner container is a negative electrode can. According to the present invention, by applying a silicone resin to the exposed portion of the negative electrode can, the electrolyte component (alkaline component) that has crawled up due to leakage can be retained between the silicone resin and the negative electrode can, and in the unlikely event Even if liquid leakage occurs during use, it is possible to minimize equipment failure due to leaked alkali components. Furthermore, the battery manufactured according to the present invention is not easily short-circuited.

  According to the present invention, since the fitting member and the inner container surface are coated with the silicone resin, the electrolyte does not come out of the silicone coating even when the electrolyte leaks from the fitting portion. For this reason, it is possible to prevent the internal terminals of the electronic device from being soiled and broken.

It is a section schematic diagram showing a flat battery of an embodiment of the present invention. It is a figure which shows the short test of this invention. It is a XPS analysis result of the negative electrode can surface of the battery of the Example of this invention. It is a XPS analysis result of the negative electrode can surface of the battery of a comparative example.

Hereinafter, an embodiment embodying the present invention will be described with reference to FIG.
FIG. 1 is a schematic cross-sectional view showing an example of a flat battery according to an embodiment of the present invention. In FIG. 1, the flat battery will be described using an alkaline battery as an example. The present invention can also be implemented in primary batteries, secondary batteries, and capacitors other than alkaline batteries.

  1 includes a negative electrode can 1 (inner container) as a cap formed in a hat shape, a positive electrode can 2 (outer container) as a case formed in a bottomed cylindrical shape, a negative electrode can 1 and a positive electrode. And a gasket 3 (fitting member) made of a synthetic resin sandwiched between the can 2.

  Inside the negative electrode can 1 and the positive electrode can 2, in order from the bottom surface side of the positive electrode can 2, a positive electrode 4 using silver oxide as an active material, a separator 5 that separates the positive electrode 4 and the negative electrode 7, and a nonwoven fabric as an electrolyte solution holding agent 6. A negative electrode 7 using zinc as an active material is laminated, and the electrolytic solution 8 is filled. The positive electrode can 2 is sealed by caulking the opening to the negative electrode can 1 via the gasket 3. Here, as the electrolytic solution, for example, an alkaline electrolytic solution mainly containing sodium hydroxide (NaOH) or potassium hydroxide (KOH) can be used.

  A silicone resin is applied to the exposed portion of the negative electrode can on the flat battery assembled as described above. As this silicone resin, a coating agent 9 made of a mixed solution of siloxane and a chelating agent was used. The flat battery after application was left at room temperature for 7 days to dry and solidify the silicone resin. Here, when the water repellent is attached to the negative electrode can, it is desirable to remove it beforehand by acid treatment or the like. By performing this treatment, a mixed solution of siloxane and chelating agent can be evenly applied.

(Example)
As a liquid leakage test, n = 100 alkaline batteries, which are flat batteries manufactured as described above, were placed in an environment at a temperature of 60 ° C. and a relative humidity of 90%. Thereafter, the sample was taken out every 10 days, and the occurrence rate of liquid leakage was examined with a microscope and pH test paper. Further, the batteries were arranged as shown in FIG. 2, a short test was performed by overlapping the batteries, and the voltage was measured every 10 minutes. Here, FIG. 2 is a figure which shows the short test of this invention. Moreover, the negative electrode can surface was analyzed by XPS (X-ray photoelectron spectroscopy). The XPS used in this analysis is owned by the Ministry of Education, Culture, Sports, Science and Technology's advanced research facility in-service promotion project conducted at the International Research Center for Energy Safety Science, Graduate School of Engineering, Tohoku University.

(Comparative example)
As a comparison of the examples, a liquid leakage test, a short test, and an XPS analysis similar to those of the examples were performed without applying anything to a silver oxide battery that is a flat battery.

  The results of the liquid leakage resistance test are shown in Table 1. Table 1 shows the leakage rate when observing Examples and Comparative Examples left in the above environment. In Table 1, no leakage was observed in the examples even after storage for 50 days, but in the comparative example, 30% leakage was observed at 30 days, 48% at 40 days, and 100% leakage at 50 days. . From this comparison result, it can be seen that the battery of the present invention is superior in leakage resistance compared to the comparative example. Further, the battery of the example was put into the test until it leaked. And although the pH test paper was applied to the leak location of the battery judged to be leaking in the appearance inspection, there was no alkaline reaction.

  The results of the short test are shown in Table 2. In the short test, the short battery S and the flat battery B according to the present invention are arranged as shown in FIG. 2, and one flat battery B is placed on the short battery S. The positive electrode can of the flat battery B that is on the upper side is in contact with the positive electrode can and the negative electrode can of the short battery S that is on the lower side, and is short-circuited. Table 2 shows the change in voltage according to each short time when the circuit is forcibly shorted in this way. According to Table 2, the voltage does not change in the example, whereas the voltage in the comparative example decreases due to a short circuit. From this, it can be seen that the battery of the present invention is not easily short-circuited externally.

  FIG. 3 shows the result of XPS analysis on the surface of the negative electrode can of the battery of Example, and FIG. 4 shows the result of Comparative Example. It was confirmed that Ni was present on the outermost surface of the battery of the comparative example and that a substance having an alkyl group was present on the outermost surface of the battery of the example. The alkyl group is hydrophobic. Therefore, it turns out that it has a structure which prevents the penetration | invasion of the water | moisture content from the coating agent surface of this invention.

DESCRIPTION OF SYMBOLS 1 Negative electrode can 2 Positive electrode can 3 Gasket 4 Positive electrode 5 Separator 6 Nonwoven fabric 7 Negative electrode 8 Electrolyte 9 Coating agent B Alkaline battery S Short battery

Claims (3)

Enclosing a power generation element inside the inner and outer containers;
Caulking the inner container and the outer container via the fitting member;
Applying a silicone resin from the inner container surface to the fitting member;
A step of drying and solidifying the silicone resin,
Removing the silicone resin from the terminal contact portion ;
A method for producing a flat battery comprising : The method for producing a flat battery according to claim 1, wherein the silicone resin has an alkyl group. The method of manufacturing a flat battery according to claim 1 or 2, wherein the inner container is a negative electrode can.

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