JPS58131661A - Manufacture of button type alkaline cell - Google Patents

Abstract

PURPOSE:To improve the heavy load discharge characteristic of a button type alkaline cell, by inserting a positive pole agent forming material having proper gap rate into a positive pole can while injecting a portion of alkali electrolyte then pressure contacting against the positive pole can and after injecting the electrolyte exceeding the gap volume leaving it for predetermined hours and removing the excessive electrolyte. CONSTITUTION:Positive pole agent 3 where desired micro powder graphite is added in manganese dioxide is accurately weighed, then molded into a tablet and mounted on a positive pole can 1 and after injecting an electrolyte and dispersing, an L-shaped positive pole ring 2 is mounted on said agent 3 to pressure contact against the can 1. Excessive electrolyte is injected onto the agent 3 and after leaving for 20min, the excessive electrolyte is removed and an electrolyte holding member 5 composed of an alkali-resistant separator 4 and an alkali-resistant fiber is mounted. while a negative pole 7 is mounted on a sealing board 6 then a gasket 8 is applied and the electrolyte is injected to the negative electrode 7. Said board 6 and can 1 are assembled to complete a button type alkali manganese cell. The gap rate of the tablet-shaped positive pole agent molding material is in the range of 20-40%.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a button alkaline battery, and its purpose is to stabilize and improve battery characteristics, particularly to completely improve heavy load discharge characteristics.

In recent years, with the development of small electronic devices such as cameras, watches, and hearing aids, button-type alkaline batteries have come to be used as power sources for these devices, but the operating temperature range of each device has also expanded to around -20C to soC. It has spread. Along with this, there is a need to improve the low-temperature, high-load characteristics of button-type alkaline batteries.

Conventionally, in order to improve and stabilize the low-temperature, high-load customization of this type of battery, there has been a method in which the positive electrode mixture is pressure-bonded to the positive electrode can and then the electrolyte is injected, or the electrolyte is injected into the positive electrode material and the 4' core material. Batteries have been constructed using a method in which the mixture is mixed and prepared as a positive corrosion agent and is pressure-bonded to the positive electrode can. However, in the former method, because the electrolyte is injected into the positive electrode mixture that has already been pressurized into the positive electrode can, the positive electrode mixture cannot absorb enough liquid, and the amount of liquid absorbed is not constant. It was difficult to mass produce batteries with stable characteristics. Additionally, there was a battery storage point. In addition, in the latter method, secondary particles are formed when the positive electrode material powder and electrolyte are mixed, reducing the accuracy of weighing the positive electrode mixture. The discharge life is not constant, making it impractical.

The present invention eliminates the above-mentioned drawbacks by precisely weighing the positive electrode mixture, forming it into a rough tablet, inserting it into the positive electrode can, and then pouring a portion of the required amount of electrolyte into it. The process of absorbing
Next, the positive electrode mixture is pressure-bonded to the positive electrode can. and a further step of injecting an electrolyte in excess of the pore volume of the mixture into the pressure-bonded mixture, leaving it to stand for a predetermined period of time, and then removing the excess electrolyte. This is a method for manufacturing button-type alkaline batteries.

Here, the porosity of the tablet-shaped positive electrode mixture molded body is 20
-40% range. When the porosity is less than 20 inches,
The injected electrolyte cannot diffuse uniformly into the mixture, and when it is pressure-bonded to the positive electrode can in the next process, the electrolyte is unevenly distributed in the positive electrode mixture, which is not effective enough for high-load discharge characteristics. does not bring about Moreover, if the thickness exceeds the limit, the molded product becomes brittle and becomes chipped or cracked, making it difficult to handle.

The amount of electrolyte initially injected into the above-mentioned mixture molded body is a part of the required amount to be finally added to the mixture, and is approximately equal to the void volume of the mixture pressed into the positive electrode can. A value of 60 inches or less is appropriate. If the amount of liquid injected is too large, there will be an inconvenience that the mixture will stick to the jig V when pressurizing the positive electrode can. On the other hand, if the amount is too small, the effect of uniformly dispersing the electrolyte throughout the mixture will be weakened.

In the present invention, a part of the required amount of electrolyte is poured into the positive electrode mixture molded to have an appropriate porosity as described above in the positive electrode can, and then the mixture is pressurized and bonded to the positive electrode can. Inject the liquid,
Since we use a method that removes excess liquid that is not absorbed by the mixture after standing, it is possible to uniformly contain a large amount of electrolyte in the mixture, and also to ensure that the mixture is sufficiently compressed to the positive electrode can. be able to. Therefore, it is possible to improve the low-temperature heavy load characteristics and the stability of the internal resistance during storage.

Next, the present invention will be explained by examples.

FIG. 1 shows a button-type alkaline manganese battery LH44 type, and its effects and characteristics will be described with a specific example in which the present invention is applied to this battery.

First, a desired finely powdered black powder is added to manganese dioxide powder and mixed thoroughly. This positive electrode mixture is accurately weighed and pressurized to form it into a tablet shape. This molded body is placed in the positive electrode can 1, and an electrolytic solution is poured into the mixture. After this electrolytic solution has sufficiently diffused into the mixture, a bevel-shaped positive electrode ring 2 is placed on the mixture and is pressed onto the positive electrode can using a jig. 3 shows this positive electrode mixture. Next, an excess amount of electrolyte was poured onto this positive electrode mixture 3, and after leaving it for 20 minutes, the excess electrolyte remaining on the positive electrode mixture was removed, and then an alkali-resistant separator 4 was placed on the mixture.
and electrolyte holding material 5'f made of alkali-resistant fiber:
Place it. On the other hand, a negative electrode 7 made of a mixture of zinc hydrate powder and carboxymethylcellulose (vaginal enhancer) salt is installed on the sealing plate 6, and an elastic gasket 8 made of synthetic rubber or synthetic resin is attached around it. Inject the electrolyte into step 7. This sealing plate and the above-mentioned positive electrode can are combined and the opening of the positive electrode can is tightened to complete a button-shaped alkaline manganese battery.

As described above, the porosity of the positive electrode mixture molded body was set to 33 cm,
The initial injection t was equivalent to approximately 46% of the pore volume of the mixture of pressurized pressure 4 barley to the positive electrode can in the next process, and the porosity of the mixture after pressure bonding to the positive electrode can was approximately 16%. A battery according to the present invention is designated as A.

In addition, according to the conventional method, the positive electrode mixture molded body was pressure-bonded to the positive electrode can together with the positive electrode ring so that the porosity of the mixture was about 15 cm, and then the electrolyte was injected and the assembled battery was removed. Let it be B.

When the amount of electrolyte in the mixture of these batteries was compared, in battery A it was equivalent to about 90% of the porosity of the mixture, but in battery B it was equivalent to about 70%.

Next, FIG. 2 shows the results of continuous discharge under a 20C, 100Ω load for batteries A and H, and FIG. 3 shows a comparison of the changes in internal resistance over time.

As is clear from these results, the effects of the present invention are significant.

In the examples, an alkaline manganese battery was explained, but the effect of the colleague is also recognized in button-shaped silver oxide batteries and mercury batteries that use an alkaline aqueous solution as the electrolyte.

As described above, according to the present invention, it has stable performance,
A button-type alkaline battery with excellent heavy load discharge characteristics can be obtained.

[Brief explanation of drawings]

Figure 1 is a partially sectional side view of a button-type alkaline manganese battery used in an embodiment of the present invention, and Figure 2 is a 120C
Fig. 3 is a graph comparing the 100Ω continuous discharge characteristics of , and Fig. 3 is a graph comparing the change in internal resistance over time. 1...Positive electrode can, 2...--Positive electrode ring, 3...
...Positive electrode mixture, 4...Separator, 6...
... Electrolyte holding material, 6... Sealing plate, 7...
・Negative electrode.

Claims (1)

[Claims] A step of inserting a positive electrode mixture molded body with a porosity of 20 to 40% into a positive electrode can, and injecting a part of the required amount of alkaline electrolyte into this positive electrode mixture, and then adding the entire positive electrode mixture to the positive electrode can. Pressure 7d to
A method for producing a button-type alkaline battery, which comprises the steps of: injecting an amount of electrolyte over the nitrogen gap into the positive electrode mixture, leaving it to stand for a predetermined period of time, and then removing excess electrolyte. .