JP3177486B2 - Manufacturing method of non-sintered electrode - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for continuously producing a non-sintered electrode plate used in an alkaline storage battery.

[0002]

2. Description of the Related Art Conventionally, the electrode plate has a porosity of 85%.
So-called sintered electrode plates using the front and rear nickel sintered bodies have been generally used. However, in recent years, Japanese Patent Application Laid-Open No.
As shown in Japanese Patent No. 161252, a highly porous material having a porosity of 95% or more, such as foamed nickel or sintered metal fiber, is used, and an active material containing nickel hydroxide or cadmium oxide as a main component is used for the metal porous material. A so-called non-sintering type manufacturing method of filling an electrode plate has been developed.

There are a batch type manufacturing method and a continuous type manufacturing method in this non-sintered type electrode plate manufacturing method, but a continuous type manufacturing method is more preferable in order to improve productivity.
However, it is difficult to produce a continuous body of the porous metal body used in the non-sintering type production method because of a possibility of cutting when a large tension is applied and problems in plating.
In addition, because of the necessity of controlling the slurry amount of the active material, a sampling inspection is required during the process. Considering these facts, in order to improve the productivity by making the manufacturing process of the electrode plate continuous, the connection technology of the base is extremely important.

[0004]

Here, as a general connection method of a porous metal body, a method of melting and connecting a part of a metal, such as seam welding or laser welding, is known.

However, since the porous metal body has a high porosity, a space is easily formed between the porous metal bodies when they are overlapped. For this reason, when the connection is made by the above-described method, a portion where the welding strength is reduced due to a spark or the like occurs. In addition, since the porous metal body is corrugated, a portion where welding cannot be performed is generated, and a portion where the welding strength is reduced also occurs. For these reasons, the welding method has a problem that the connection strength varies.

Therefore, in order to eliminate variations in welding, there is a method in which a porous metal body is pressurized in advance to reduce the porosity. However, such a method complicates the manufacturing process. In addition, JP-A-53-25839
As shown in the publication, a large-scale apparatus is required to perform welding.

On the other hand, as another connection method of the metal porous body, there is a method of mechanically connecting with a metal needle or the like (ex, stapler). However, if the metal pieces such as the metal needles are present in the rolling and cutting steps after the connection, they may be caught or the like, so that there is an inconvenience in performing continuous production. In addition, there is a problem that a large-scale facility is required to connect a wide metal porous body with a metal needle or the like.

The present invention has been made in view of the above situation, and an object of the present invention is to provide a method of manufacturing a non-sintered electrode capable of solving the above-mentioned disadvantages.

[0009]

According to the present invention, in order to achieve the above object, two metal porous bodies having an average pore diameter of 300 μm or less are overlapped with each other, and then pressurized to form a substrate. The method is characterized by including one step and a second step of continuously filling the base with the active material.

[0010]

As shown in FIG. 3, a large number of fine concave portions 3 and convex portions 4 are present on the surfaces of the porous metal bodies 1 and 2;
When the two porous bodies are overlapped, the convex part 4 of the porous metal body
And the concave portion 3 of the other porous metal body overlap. And
When pressure is applied in this state, as shown in FIG. 4, the convex portion 4 is fitted into the concave portion 3, and a large number of caulked portions are formed at the overlapped portion. As a result, a very high bonding strength can be obtained, and since the caulked portion is formed uniformly in the overlapped portion, the variation in the connection strength can be reduced. In addition, since the pressure is merely applied, the manufacturing process does not become complicated, and no large-scale apparatus is required, so that the equipment cost does not increase.

The average pore diameter of the porous metal body is set to 300 μm.
By setting it to m or less, it becomes possible to make more uneven portions exist, the bonding strength increases, and the variation in connection strength can be reduced.

[0012]

【Example】

[Example] As shown in FIGS. 1 and 2, the basis weight was 500 g / m ^2.
And initial thickness t ₂ = 2 mm, width t ₁ = 100 mm, average pore diameter 20
Using two pieces of foamed nickel having a thickness of 0 μm, they are overlapped with each other to have a width t _3.
= 5mm. Next, the overlapped portion (total thickness is 4 mm) is pressed to a thickness of 2.0 mm.
To produce a nickel core.

In the above embodiment, the average pore diameter is 2
Nickel core bodies were produced in the same manner using 50 μm and 300 μm, and the same foamed nickel as the others. Comparative Example In the above example, the average pore size was 350 μm.
A nickel core was produced in the same manner, using the same foamed nickel except that the thickness was 400 μm. (Experiment) The nickel core produced as described above was cut into five equal parts as shown by the two-dot chain line in FIG. 1 to produce five samples each having a width of 20 mm. Then, the tensile strength of these samples was examined, and the results are shown in Table 1 below.

The tensile strength of the foamed nickel alone is 5
Kg / cm.

[0015]

[Table 1]

According to Table 1, the use of a material having an average pore size of 300 μm or less can increase the tensile strength and reduce the variation in strength. This is because, when the average pore diameter is small, the number of convex portions per unit area increases, so that a large number of caulked portions are formed. Therefore, the average pore size of the foamed nickel is 300
It is necessary to be less than μm.

In the above embodiment, only the method of connecting foamed nickel is shown. However, in the case of manufacturing a non-sintered electrode, an active material filling step is required. .

After the nickel core (substrate) prepared as described above is dipped in a tank filled with an active material slurry (mainly nickel hydroxide, which contains methylcellulose as a paste), excess active material is added. The material slurry is made by scraping off with a scrubber.

[0019]

As described above, according to the present invention, a large number of convex portions formed on the surface of the porous metal body are fitted into the concave portions, and an infinite number of caulked portions are formed at the overlapping portion. . Therefore, a very high joining strength can be obtained, and the variation in the connection strength between the porous metal bodies can be reduced. In addition, since connection is made by simply applying pressure, the manufacturing process is not complicated, and a large-scale device is not required.

[0020] From the above, there are effects that the quality of the non-sintered electrode can be remarkably improved, the manufacturing process can be simplified, and the equipment cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a plan view showing a method of superimposing foamed nickel.

FIG. 2 is a side view showing a method of superimposing foamed nickel.

FIG. 3 is an explanatory view showing a surface state of foamed nickel.

FIG. 4 is an explanatory view showing a state where two convex portions of nickel foam are fitted into concave portions.

[Explanation of symbols]

 1.2 Porous metal body 3 Concave part 4 Convex part 5 Foamed nickel

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Mitsuwa Kuwaki 2-5-5 Keihanhondori, Moriguchi-shi, Osaka Sanyo Electric Co., Ltd. In-house (72) Yoshinori Nakayama 2-5-2 Keihanhondori, Moriguchi-shi, Osaka No. 5 Sanyo Electric Co., Ltd. In-house (56) References JP-A-54-148234 (JP, A) JP-A-61-143941 (JP, A) JP-A-57-43361 (JP, A) JP-A Sho 50 −36936 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01M 4/24-4/34 H01M 4/64-4/84

Claims (1)

(57) [Claims] 1. A first step in which two metal porous bodies having an average pore diameter of 300 μm or less are overlapped and then pressurized to form a substrate, and the substrate is continuously filled with an active material. And a second step.