JPS5829580B2 - Silver oxide battery manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a battery using silver oxide as an anode.

Silver oxide batteries, which use monovalent or divalent silver oxide as an anode, have excellent discharge performance despite their small size, and are now widely used in small electronic devices such as cameras and watches. It has become.

This silver oxide battery certainly has the advantage of having a higher discharge capacity per unit volume than other types of batteries, but
However, there is still a considerable gap between the actually obtained discharge capacity and the theoretically required discharge capacity, and therefore,
There also remains much room for improvement in its discharge performance.

By the way, the conventional manufacturing method of a silver oxide battery is to form an anode by molding an anode material mainly made of finely powdered monovalent or divalent silver oxide (Ag20 or Age) into a predetermined shape. This was placed opposite the cathode with a separator impregnated with an electrolytic solution interposed therebetween to form a power generation element.

This power generation element is sealed and loaded into a battery case to form a battery.

In a silver oxide battery constructed in this manner, the condition of the anode has a large influence on its discharge performance.

In particular, with regard to discharge capacity, the particle size of the silver oxide in the anode is a problem; if the particle size of the silver oxide is large, the effective surface area that can contribute to power generation becomes smaller, which greatly affects the discharge performance.

Therefore, it is required that silver oxide, which is the main material of the anode, be used in the form of as fine particles as possible.

However, it is difficult to obtain silver oxide in the form of fine particles.
There are many technical difficulties, and therefore there are limits to the improvement of discharge performance by making the particle size finer.

In addition, it is known that not only this type of battery but batteries in general undergo self-discharge that consumes the active material when in a resting state such as during storage, and this self-discharge impairs storage stability, which is important for battery performance. Therefore, it is desirable to reduce the number of occurrences as much as possible, or eliminate them at all if possible.

However, in reality, self-discharge cannot be completely eliminated, so care must be taken to preserve the storage environment and to suppress self-discharge as much as possible, especially when storing for long periods of time. It was something.

This invention was made in view of the above-mentioned background, and its purpose is to overcome the conventional technical difficulties and to ultimately make the consistency of silver oxide in the anode even finer. It is an object of the present invention to provide a method for manufacturing a silver oxide battery that has improved discharge performance, can be easily manufactured, and has excellent storage stability.

In order to achieve this object distantly, the present invention provides a method for manufacturing a silver oxide battery, in which a material mainly composed of reduced silver (Ag) fine powder is used as an anode material for the battery, and after molding this into a predetermined shape, a separator is formed. It is characterized in that it is loaded in a laminated state with a cathode material and then sealed to form a battery, and then subjected to a charging process to form a silver oxide battery.

Examples of the present invention will be described in detail below.

First, a mixture of 95 parts by weight of reduced silver with a particle size of 0.5 to 2 F and 5 parts by weight of graphite of approximately the same particle size was diluted with xylene to create an epoxy resin (the amount of resin was 2 to 2 parts by weight per 100 parts by weight of the mixture). 5 parts by weight).

Thereafter, xylene is volatilized to obtain a viscous material.

After rolling this viscous material to a predetermined thickness, it is punched into a predetermined shape to form the anode material of the battery.

Here, the following method is suitable as a method for forming the anode material.

FIG. 1 shows one embodiment of this, in which the anode material 1a viscousized as described above is sequentially fed from a popper 2a onto a conveyor belt 2b.

The belt 2b is a film made of fluororesin, stainless steel, or the like, and is driven by rolls 2c and 2d to convey the anode material 1a.

The anode material 1a supplied onto the belt 2b is sequentially made uniform in thickness by slotting plates 2e and 2f while being conveyed, and further rolled together with the belt 2b by rolling rolls 2d and 2ct.

The thus rolled anode material 1a is separated from the bell 2b by a claw 2g, and sent to a punching process via a buffer 2j by rolls 2h and 2i.

In the punching step, the punch 2 and the die 21 are used to sequentially punch out the anode material 1a rolled to a certain thickness into a predetermined shape.

Thereby, the anode material 1a molded into pellets is continuously mass-produced.

The anode material 1a mass-produced as described above is shown in Fig. 2a.
An anode material 1a mainly composed of reduced silver (Ag), which has been molded as shown in the figure, is loaded into an anode can 3a as shown in the figure.

Then, as shown in FIG.
b through the gasket 3c, and then bend the vicinity of the opening of the anode can 3a inward to attach the gasket 3c.
The inside of the case 3 is hermetically sealed by squeezing the inside of the case 3.

When the battery thus formed is subjected to a subsequent charging process, the reduced silver (Ag) in the anode material 1a reacts to become silver oxide (Ag20).

That is, the anode material 1a can be an anode material.

In this case, the cathode material 1c used is, for example, viscous zinc oxide (XnO) in the case of a silver-zinc oxide battery.

This zinc oxide (XnO) becomes metal zinc (Xn) through charging treatment.

That is, it becomes the electrode material of the battery together with the anode material 1a.

According to the method described above, a flat silver oxide battery can be manufactured with high efficiency, but the following two points should be noted here.

First, silver oxide (Ag20 or AgO) is Ag.

→ Since there is a chemical property that tends to stabilize in the order of Ag2O + Ag, using reduced silver (Ag), which is the most stable state, from the beginning makes the process much easier.

When silver oxide (AgO or Ag20) is used as the initial raw material, a portion of the material becomes reduced silver (Ag), so it is necessary to take other measures to prevent this.

This also means that the above-mentioned charging process is not performed, that is, the reduced silver (Ag) in the above-mentioned anode material 1a is replaced with silver oxide (A g
20) If you store it without storing it, it will function as a battery, but it has not yet been given that function.
Moreover, due to the stability of reduced silver (Ag), self-discharge can be suppressed almost completely, dramatically improving storage stability, and storage conditions are not as strict as with conventional batteries of this type. There is no need for troublesome maintenance under environmental conditions.

By performing the above-described charging process immediately before shipping, silver oxide batteries with stable quality can be supplied to the market.

Next, when reduced silver (Ag) is made into fine powder, silver oxide (Ag
This means that the particle size can be made smaller than in the case where 20 or Age) is made into fine powder.

Figure 3 shows a comparison between the particle size distribution of a fine powder of silver oxide (Ag20) (curve A) and the particle size distribution of a fine powder of reduced silver (Ag) [curve B]. As is clear from the same figure, the particle size of the reduced silver (Ag) fine powder is
The diameter can be made much smaller than that of silver oxide (Ag20).

As a result, an anode material with a larger effective surface area that can contribute to power generation can be obtained, and the discharge capacity per unit volume of the silver oxide battery can be increased.

The test results shown below are based on a silver oxide battery (diameter: 11.1 mm, height: 2.057 mm) manufactured by the method described above.
This figure compares the discharge performance of a silver oxide battery of the same type manufactured by a conventional method under the same conditions.

The values shown in the table are the initial value at 20℃ and the value at 60℃.
1.20V with 6.5Ω continuous discharge after 20 days stock
This shows the duration of time.

FIG. 4 shows another embodiment, in which an anode material 1a in which a differential powder of reduced silver (Ag) is made viscous together with a conductive material is used, as in the previous embodiment.

The anode material 1a is supplied by a hopper 4b onto a separator film 1b that is continuously unwound from a roll 4a.

For example, porous polypropylene is suitable as the separator film 1b.

Anode material 1 supplied on this separator film 1b
The thickness of the film a on the film 1b is sequentially made uniform by the cutting plates 4c t 4d.

Then, the film 1b is rolled by rolling rolls 4e and 4e.
Rolled with roll 4f.

After passing through a buffer of 4g and 4h, it is continuously sent to the punching process.

In the punching step, the anode material 1a spread out in layers on the film 1b is punched together with the film 1b into a predetermined shape using a punch 41 and a die 4j.
As shown in FIG. 5a, a power generating element component 1' is mass-produced in which an anode material 1a and a film 1b, which is a separator, are assembled in advance in a laminated state.

This power generating element component 1' is loaded into an anode can 3a with its film 1b facing upward, as shown in FIG.

After the film 1b is impregnated with an electrolytic solution, as shown in FIG.
is fitted into the anode can 3a via the gasket 3c, and the anode can 3a is further bent inward near the opening to squeeze the gasket 3c and seal the inside of the case 3.

Thereafter, a charging process is performed to convert the reduced silver (Ag) in the anode material 1a into silver oxide (AgO) to complete the battery.

In this case, although the same can be said for the above-mentioned embodiment, the above charging process does not need to be performed immediately. For example, if it is to be stored for a long period of time, it may be stored without performing the charging process, and before shipping. It may also be carried out at the same stage as product inspection.

In this embodiment, the polar material and the separator can be directly assembled in advance in a laminated manner, so there is an advantage that the subsequent assembly work of the power generation element is greatly simplified.

Now, referring to yet another embodiment, the film 1b rolled and punched together with the anode material 1a can be used not only as a battery separator but also as an electrolyte storage layer.

In this case, the film 1b rolled together with the anode material 1a
In this case, a material that is more suitable as an absorbent material than as a separator is used.

The porous polypropylene described above can also be used as its absorbent material.

According to this embodiment, the anode material 1a and the electrolyte storage layer can be obtained in a pre-assembled state, which is very advantageous in terms of increasing manufacturing efficiency.

As described above in detail in the Examples, the method for producing a silver oxide battery according to the present invention involves laminating an anode material mainly composed of reduced silver fine powder molded into a predetermined shape with a separator and a cathode material. After loading the battery, it is sealed to form a battery, and then charged to form a silver oxide battery.The particle size of the acid ft silver in the anode is made even finer as a result, greatly improving discharge performance. In addition, by performing the charging process after forming the battery, storage performance can be greatly improved.

[Brief explanation of drawings]

FIG. 1 is an abbreviated sectional view showing an embodiment of a partial process of the silver oxide mold manufacturing method according to the present invention, and FIG. 2 is a2b. C is a cross-sectional view showing the subsequent steps in order, FIG. 3 is a graph comparing the particle size state of fine silver oxide powder and that of reduced silver fine powder, and FIG. Abbreviated sectional views showing the embodiment, and FIGS. 5a, 5b, and 5c are sectional views showing each subsequent step in order. 1a...Anode material, cathode material. 1b...Film, Co".

Claims (1)

[Claims] 1. In a method for manufacturing a silver oxide battery, an anode material mainly composed of reduced silver fine powder molded into a predetermined shape is loaded in a layered state with a separator and a reducing material, then sealed to form a battery, and then charged. A method for producing a silver oxide battery, characterized in that the battery is made into a silver oxide battery through treatment.