JPH09223504A - Cylindrical alkaline battery and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cylindrical alkaline battery having large capacity and a large electric current. SOLUTION: A positive electrode mix 2 composed of a manganese dioxide, carbon and a potassium hydroxide aqueous solution and a gel-like negative electrode mix 3 composed of granular zinc, a pottasium hydroxide aqueous solution, a thickener or the like, are enclosed in a cylindrical positive electrode case 1, and the positive electrode mix 2 and the negative electrode mix 3 are separated from each other by a separator 4 composed of nonwoven fabric. A positive electrode terminal 6 is arranged in an upper central part of the positive electrode case 1, and conductive carbon powder 12 is arranged between the positive electrode case 1 of a part in which the positive electrode terminal 6 is arranged and the positive electrode mix 2. A sealing member 7 composed of a plastic material to seal an opening part is fitted to the opening part of the positive electrode case 1. A reinforcing member 8 to reinforce this sealing member 7, also a spring 9 to cover the reinforcing member 8 and a disk shaped metallic cover also serving as a negative electrode terminal 10 are installed. A brass-made current collecting pin 11 is pressed in the sealing member 7 to which the reinforcing member 8 is fitted.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of a cylindrical alkaline battery and a method of manufacturing the same, and more particularly to a cylindrical alkaline battery having a large discharge capacity and a small internal resistance.

[0002]

2. Description of the Related Art In recent years, with the spread of portable electronic devices and cordless electronic devices, there has been an increasing demand for higher capacity and larger current of cylindrical alkaline batteries that are widely used as power sources.

First, the structure of a conventional cylindrical alkaline battery will be described with reference to FIG. The tubular alkaline battery has a positive electrode mixture 2 made of manganese dioxide, carbon, and an aqueous potassium hydroxide solution in a cylindrical positive electrode case 1 having a closed upper end that also serves as a battery case and an opening at the lower end.
A gelled negative electrode mixture 3 composed of granular zinc, an aqueous solution of potassium hydroxide, a thickener and the like is incorporated, and further, a positive electrode mixture 2
The negative electrode mixture 3 and the negative electrode mixture 3 are separated by a separator 4 made of a non-woven fabric. Further, the outer peripheral surface of the cylinder of the positive electrode case 1 is covered with the outer label 5, and the positive electrode terminal 6 is provided at the center of the upper portion of the positive electrode case 1. A sealing member 7 is fitted into the opening of the positive electrode case 1 in order to seal the opening. The sealing member 7 is made of a plastic material such as nylon or polypropylene, and a reinforcing member 8 is installed to reinforce the sealing member 7, and a disk 9 that also serves as the spring 9 and the negative electrode terminal 10 so as to cover the reinforcing member 8. -Shaped metal cover is attached. A brass collecting pin 11 is press-fitted into the sealing member 7 into which the reinforcing member 8 is fitted.

By the way, as described above, in order to increase the capacity of the cylindrical alkaline battery, it is necessary to increase the filling amount of the active material in the positive electrode and the negative electrode. However, because of volume restrictions, it is conceivable to reduce the amount of carbon having a relatively large volume ratio and increase the amount of active substance. However, when the amount of carbon is reduced, the positive electrode case 1 and the positive electrode mixture are mixed. There is a problem that electrical contact with 2 cannot be sufficiently made and the internal resistance becomes large.

As a countermeasure against these problems, in order to improve the electrical contact between the positive electrode case 1 and the positive electrode mixture 2, Japanese Patent Publication No.
As disclosed in Japanese Patent No. 20334, a plurality of tentatively formed ring-shaped positive electrode mixture 2 are stacked in a positive electrode case 1, and a core rod is inserted into a hollow portion of these positive electrode mixture 2 to form an outer periphery of the core rod. The punch is slidably mounted on the positive electrode mixture 2 so that the positive electrode mixture 2 is compressed between the positive electrode case 1 and the core rod so as to be in close contact with the inner wall of the positive electrode case 1. There is.

Further, in order to enhance the current collecting ability on the inner surface of the positive electrode case 1, a conductive paint obtained by dissolving and decomposing conductive carbon powder or metal powder and synthetic resin in an organic solvent such as toluene is used for the positive electrode case 1. For example, it is applied to the inner surface and dried to form a conductive film.

However, the positive electrode material mixture 2 is added to the positive electrode case 1.
In the method of pressurizing inside, the density of the upper portion of the positive electrode mixture 2 is high, but the pressure is not sufficient in the lower portion, and therefore the adhesion between the positive electrode case 1 and the positive electrode mixture 2 is poor and sufficient. No electrical contact. Further, when a conductive coating is applied to the inner surface of the positive electrode case 1 and dried to form a conductive coating, there is a problem that the volume of active material filled is reduced due to volume loss due to the synthetic resin.

[0008]

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a cylindrical alkaline battery having a high capacity and a large current by improving the electrical contact between the positive electrode case and the positive electrode mixture, and a method for manufacturing the same. Is what you are trying to do.

[0009]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and in a cylindrical alkaline battery using a positive electrode mixture having a carbon content of 3% by mass or more and 8% by mass or less, a positive electrode case A cylindrical alkaline battery in which a conductive substance is disposed between the positive electrode case and the positive electrode mixture on the positive electrode mixture side of the portion where the positive electrode terminal is provided.

The conductive material is carbon powder, or
Use metal powder.

Carbon content is 3% by mass or more and 8% by mass
In a cylindrical alkaline battery using the following positive electrode mixture, a conductive substance is placed on the positive electrode mixture side of the portion where the positive electrode terminal of the positive electrode case is provided, and then the positive electrode mixture is filled, and then the positive electrode mixture is added. The above problem is solved by using a method for manufacturing a cylindrical alkaline battery in which the conductive substance is molded by applying pressure from above the agent.

According to the cylindrical alkaline battery having the structure of the present invention and the method for manufacturing the same, the electric contact between the positive electrode case and the positive electrode mixture can be sufficiently ensured, and thus a high capacity, large current cylindrical alkaline battery can be formed. can do.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of a cylindrical alkaline battery according to the present invention will be described with reference to FIGS. 1 and 2. FIG. 1 is a cross-sectional side view showing an embodiment of a cylindrical alkaline battery according to the present invention, and FIG.
It is an enlarged view of the principal part concerning the present invention.

The structure of the cylindrical alkaline battery according to the present invention is composed of manganese dioxide, carbon, and an aqueous solution of potassium hydroxide in a cylindrical positive electrode case 1 having an upper end portion also serving as a battery case closed and an opening portion at the lower end portion. Positive electrode mixture 2,
A gelled negative electrode mixture 3 composed of granular zinc, an aqueous solution of potassium hydroxide, a thickener and the like is incorporated, and further, a positive electrode mixture 2
The negative electrode mixture 3 and the negative electrode mixture 3 are separated by a separator 4 made of a non-woven fabric. Further, the outer peripheral surface of the cylinder of the positive electrode case 1 is covered with the outer label 5, and the positive electrode terminal 6 is provided at the center of the upper portion of the positive electrode case 1. This positive electrode terminal 6
The conductive carbon powder 12 is disposed between the positive electrode case 1 and the positive electrode mixture 2 at the portion where the conductive carbon powder 12 is provided, which is a feature of the present invention.

A sealing member 7 is fitted in the opening of the positive electrode case 1 to seal the opening. The sealing member 7 is made of a plastic material such as nylon or polypropylene, and the reinforcing member 8 is used to reinforce the sealing member 7.
Is installed, and the spring 9 covers the reinforcing member 8.
And a disk-shaped metal cover that also serves as the negative electrode terminal 10 is attached. Sealing member 7 in which the reinforcing member 8 is fitted
A brass current collecting pin 11 is press-fitted into the.

Next, the method of manufacturing the cylindrical alkaline battery of the present invention will be described. The positive electrode case 1 is placed with its opening facing upward, the conductive carbon powder 12 is put therein, and then it is temporarily formed into a ring shape. The molded positive electrode mixture 2 is inserted. Next, the core rod is inserted into the hollow portion of the positive electrode mixture 2, and the punch is slidably mounted on the outer periphery of the core rod to press from the upper portion of the positive electrode mixture 2 to form the conductive carbon powder 12 to a predetermined density. To do. After that, the core rod and the punch are extracted from the positive electrode case 1, the separator 4 and 39% potassium hydroxide aqueous solution, and the negative electrode mixture 3 are loaded in the hollow portion of the positive electrode mixture 2, and the opening of the positive electrode case 1 is sealed with the sealing member 7. To form a tubular alkaline battery.

Next, the characteristics of the cylindrical alkaline battery according to the present invention will be described. This is obtained by making an example made according to the present invention and a cylindrical alkaline battery to be compared therewith, measuring the respective short-circuit currents and continuous discharge durations, and comparing them.

The specific structure of the embodiment is as follows. Manganese dioxide, graphite, and a 39% aqueous potassium hydroxide solution were mixed uniformly at a ratio shown in Table 1 to prepare a positive electrode mixture 2
(Mixtures A to E) are formed, and 3.6 g of each is temporarily molded into a ring shape having an outer diameter of 13.2 mm, an inner diameter of 9.1 mm, and a height of 15.0 mm. Approximately 20 mg of graphite was placed as the conductive carbon powder 12 in the positive electrode case 1, and then three positive electrode mixture 2 were inserted, and 3 ton / c from the top.
Pressurize with a pressure of m ² . Next, the hollow space of the positive electrode mixture 2 is filled with the separator 4, the 39% potassium hydroxide aqueous solution, and the negative electrode mixture 3, and the opening of the positive electrode case 1 is sealed by the sealing member 7.

[0019]

[Table 1]

Further, the comparative example is formed in the same manner as the other examples except for graphite which is the conductive carbon powder 12 of the above-mentioned examples.

With respect to the cylindrical alkaline batteries of Examples and Comparative Examples, the short-circuit current value after standing at room temperature for 1 day and the continuous discharge duration of 10Ω were measured. The results of the short circuit current value are shown in Table 2 and the results of the continuous discharge duration are shown in Table 3.

[0022]

[Table 2]

[0023]

[Table 3] From Tables 2 and 3, it can be seen that, although the amount of the positive electrode mixture is the same in the examples and the comparative examples, the short-circuit current is larger and the continuous discharge duration is longer in the examples. . However, the amount of carbon added to the positive electrode mixture is 8%
In the above cases, the short-circuit current and the continuous discharge duration have no difference between the example and the comparative example, and when it is 3% or less, the short-circuit current is hardly obtained.

[0024]

As described above, according to the cylindrical alkaline battery of the present invention and the method for manufacturing the same, sufficient electrical contact between the positive electrode case and the positive electrode mixture can be ensured, and therefore high capacity and large capacity can be obtained. A tubular alkaline battery of current can be formed.

[Brief description of drawings]

FIG. 1 is a sectional side view showing an embodiment of a cylindrical alkaline battery according to the present invention.

FIG. 2 is an enlarged view of a main part of a cylindrical alkaline battery according to the present invention, which is denoted by reference character A in FIG.

FIG. 3 is a cross-sectional side view of a conventional cylindrical alkaline battery.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Positive electrode case 2 Positive electrode mixture 3 Negative electrode mixture 4 Separator 5 Exterior label 6 Positive electrode terminal 7 Sealing member 8 Reinforcing member 9 Spring 10 Negative electrode terminal 11 Current collecting pin 12 Conductive carbon powder

Claims (4)

[Claims] 1. A cylindrical alkaline battery using a positive electrode mixture having a carbon content of 3% by mass or more and 8% by mass or less, wherein the positive electrode mixture side of the positive electrode case is provided with the positive electrode terminal, A cylindrical alkaline battery, characterized in that a conductive substance is disposed between a case and the positive electrode mixture. 2. The cylindrical alkaline battery according to claim 1, wherein the conductive material is carbon powder. 3. The cylindrical alkaline battery according to claim 1, wherein the conductive material is a metal powder. 4. In a tubular alkaline battery using a positive electrode mixture having a carbon content of 3% by mass or more and 8% by mass or less, a conductive substance is arranged on the positive electrode mixture side of a portion where the positive electrode terminal of the positive electrode case is provided. Then, the positive electrode mixture is filled, and thereafter, the positive electrode mixture is pressed to form the conductive substance, and the method for producing a cylindrical alkaline battery.