JPH0896811A - Current collector for lead-acid battery and manufacture thereof - Google Patents

Abstract

PURPOSE: To provide a current collector for a lead-acid battery capable of effectively increasing adhesion of the current collector with an active material layer. CONSTITUTION: Blast treatment is conducted to the surface of a lead sheet raw material to form recesses 2 and to obtain a lead sheet 1. The lead sheet 1 passes through a bath 4 in which red lead oxide (Pb3 O4 ) powder 3 is put to put the red lead oxide in the recesses 2. The lead sheet 1 sent from the bath 4 is rolled with a pair of rollers 6a, 6b and the red lead oxide powder 3 is embedded in the lead sheet 1 so that the outer surface of most part of the red lead oxide powder 3 is covered with lead to obtain a sheet material. Expanding work is applied to the sheet material with an expanding machine to complete a current collector.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a current collector for lead acid batteries and a method for manufacturing the same.

[0002]

2. Description of the Related Art A lead storage battery current collector formed by using a lead or lead alloy sheet is formed by expanding or punching a lead or lead alloy sheet. Since the current collector of this type has a smooth surface, even if the active material layer is formed by filling the current collector with the paste-type active material, the current collector and the active material layer do not sufficiently adhere to each other. Therefore, the chemical conversion property is poor, and the charge acceptability after being left overdischarge is lowered. Therefore, by performing a maturing step for a long time in the production of the electrode plate, or by subjecting the surface of the lead or lead alloy sheet to a blast treatment for forming unevenness on the surface of the current collector by spraying sand particles,
It has been proposed to increase the adhesion strength between the current collector and the active material layer. However, there is a limit to increasing the adhesion strength between the current collector and the active material layer in this way.

Therefore, in a current collector for a lead storage battery proposed by the applicant in Japanese Patent Application No. 4-35108, the grid is formed on a grid (collector) formed of a lead alloy sheet heated to 200 ° C. The lead alloy particles containing Sb, which has a more noble potential than that of the above alloy, are arranged on the surface of the grid body, and the lead alloy particles and the grid body are rolled by a roller to cause the lead alloy particles to bite into the surface portion of the grid body. Was proposed. In this case, the lead alloy powder having a more noble potential than that of the alloy of the lattice is arranged on the surface of the lattice, whereby the corrosion of the lattice that is base in potential is promoted. In addition, since the lead alloy powder bites into the lattice, the reaction area that corrodes becomes large. This can improve the adhesion between the current collector and the active material layer during aging.

In addition, after that, in Japanese Patent Application No. 4-3434373, the applicant brought high-level lead oxide (PbOx: 1.13≤X≤2.0) into contact with the surface of a current collector for a lead storage battery to collect current. It has been proposed to form a tetragonal lead oxide layer on the surface of the body and then fill the current collector with an active material paste containing lead oxide as a main component. By doing so, the tetragonal lead oxide layer becomes an oxidative corrosion layer, and the adhesion between the current collector and the active material layer can be enhanced.

[0005]

However, as in the former technique, in the technique of biting the lead alloy powder having a noble potential as compared with the alloy of the lattice body into the surface of the lattice body, Since only a part of them can be incorporated on the surface of the lattice body and the lattice body needs to be heated up to about 200 ° C., there are problems that the production becomes complicated and the production takes time.

Further, in the latter technique, a high-level lead oxide is simply brought into contact with the surface of the current collector, and the surface of the current collector is not squared with the lead oxide and the square shape is formed on the surface of the current collector. A crystalline lead oxide layer is formed. As described above, since the adhesion between the current collector and the active material layer is enhanced by the so-called chemical action of promoting the oxidation of the surface of the current collector, there is a limit to enhancing the adhesion between the current collector and the active material layer. there were.

An object of the present invention is to provide a current collector for a lead storage battery which can effectively enhance the adhesion between the current collector and the active material layer.

Another object of the present invention is to provide a method for easily producing a current collector for a lead storage battery, which can effectively enhance the adhesion between the current collector and the active material layer.

[0009]

According to the present invention, a powder or particles of high-ranking lead oxide (PbOx: 1.13≤X≤2.0) formed on the surface of a sheet made of lead or a lead alloy is used. Targeting a current collector for a lead storage battery that is biting in a dispersed state, a powder or particles is embedded in the surface portion so that most of its outer surface is covered with lead or a lead alloy.

In order to manufacture such a current collector for a lead storage battery, a plurality of recesses for containing powders or particles are formed on the surface of a sheet, the recesses of the sheet are filled with the powders or particles, and then the recesses are formed. Roll the sheet. And the current collector for lead acid batteries is manufactured using the rolled sheet. If you do this,
The lead-acid battery current collector can be easily manufactured at low cost without heating the current collector as in the conventional case.

[0011]

When the high level lead oxide powder or particles are embedded in the sheet surface portion made of lead or lead alloy so that most of its outer surface is covered with lead or lead alloy as in the present invention, Since the reaction area between the lead oxide powder or particles and the sheet surface part made of lead or lead alloy becomes large,
When the active material paste is filled in the current collector, the oxidation of the current collector by the powder or particles of high-order lead oxide is effectively promoted. Therefore, the current collector and the active material layer are brought into close contact with each other by aging for a short time, the conductivity between the current collector and the active material layer is increased, and the chemical conversion property and charge acceptability of the battery can be improved. Moreover, the high-order lead oxide powder or particles react with the electrolytic solution (dilute sulfuric acid) to become PbO ₂ (positive electrode active material), which is integrated with the active material layer, and the lead sheet is oxidized by the red lead powder. As a result, an oxide layer is formed at the interface between the red lead powder and the lead sheet. For this reason, a part of the active material layer (the part where the high-order lead oxide powder was present) was buried in the surface of the sheet without falling off, and the interface between the red lead powder and the lead sheet was formed. The oxide layer serves as an anchor between the current collector and the active material layer. Therefore, the current collector and the active material layer can be effectively brought into close contact not only by the conventional so-called chemical action but also by the so-called physical action.

[0012]

Embodiments of the present invention will now be described in detail with reference to the drawings.

(Embodiment 1) FIG. 1 is a sectional view of a lead-acid battery current collector of the present embodiment. As shown in the figure, in the lead-acid battery current collector of the present embodiment, the lead powder (Pb ₃ O ₄ ) powder 3 is embedded in the recesses 2 formed by being dispersed over the entire surface of the lead sheet 1. Is formed. Lead red (Pb ₃ O ₄ ) powder 3
Most of its outer surface is covered with lead, which is a current collector.

The current collector for the lead storage battery of this example was manufactured as follows. First, a lead sheet 1 having a thickness of 2.5 mm is sprayed with particles of silica sand having an average particle diameter of 0.2 mm on the surface of the lead sheet material to perform a blasting treatment to form a plurality of recesses 2 ...
made. The average depth of the plurality of recesses is 2 to 15
μm is preferred. Next, as shown in FIG.
The lead sheet 1 is passed by a rotating machine 5 into a tank 4 containing μm red lead (Pb ₃ O ₄ ) powder 3 to form a recess 2 in the lead sheet 1.
The lead powder (Pb ₃ O ₄ ) powder 3 was put in. Then, the lead sheet 1 that passed through the tank 4 was rolled to a thickness of about 1 mm by a pair of rollers 6a and 6b, and the lead (Pb ₃ O ₄ ) powder 3 was embedded in the lead sheet 1 to form a sheet material. . Next, the sheet material was expanded by an expanding machine to complete a current collector. The lead powder has an average particle size of 5 to 20 μm.
It is preferable to use one of the following. Further, it is preferable to disperse the lead oxide powder in 50 to 80% of the surface area of the lead-acid battery current collector.

Next, a positive electrode plate was produced using the current collector for lead acid battery of this example. First, an active material paste prepared by kneading lead powder, sulfuric acid, and water was applied to the current collector for lead acid battery of this example to prepare a undried electrode plate, and the undried electrode plate was heated at a temperature of 60 ° C. and a humidity of 9
After being left in 5% for 24 hours for aging, it was left in a temperature of 60 ° C. for 24 hours for drying to prepare an unformed positive electrode plate.
Then, two unformed positive electrode plates and three known unformed negative electrode plates were laminated via a separator made of glass fiber to form an electrode plate group, and this electrode plate group was placed in a battery case. And
After the formation, a suitable amount of dilute sulfuric acid having a specific gravity of 1.32 was poured into a battery case, and then the battery was subjected to the battery formation to prepare a positive electrode plate assembled in a battery. FIG. 3 shows a partial cross section of the completed positive electrode plate. As shown in the figure, the lead oxide (Pb ₃ O ₄ ) powder 3 embedded in the lead sheet 1 reacts with the electrolytic solution (dilute sulfuric acid) to become PbO ₂ (positive electrode active material), and the active material layer 7 is formed. It is integrated. Since PbO ₂ having high conductivity is formed on the surface of the current collector in this manner, the conductivity between the current collector and the active material layer is increased, and the chemical conversion and charge acceptance of the battery are increased. Further, the lead sheet 1 is oxidized by the lead oxide powder, and an oxide layer 8 is formed at the interface between the lead oxide powder and the lead sheet 1. The oxide layer 8 serves as an anchor between the current collector and the active material layer and physically brings the current collector and the active material layer into close contact with each other.

(Embodiment 2) In the present embodiment, red lead (Pb ₃
The powder was formed in the same manner as in Example 1 except that the powder of α-PbO ₂ was dispersed in the entire surface of the lead sheet instead of the powder of O ₄ ), and the recesses were formed. It is preferable to use an α-PbO ₂ powder having an average particle diameter of 5 to 20 μm as in the case of lead tin powder, and to disperse and embed it in 50 to 80% of the surface area of the lead-acid battery current collector. preferable.

(Conventional Example) The current collector of this conventional example has the same structure as in Example 1 except that the powder of lead tin oxide is not embedded.

Next, the lead-acid batteries using the current collectors of Examples 1 and 2 and the conventional example were subjected to a test of charge acceptability after being left over-discharged. The lead storage battery had the same structure as the battery (4Ah-2V) prepared in Example 1 described above.
Then, each battery was discharged with a resistance of 0.85 ohms for 24 hours (corresponding to an initial current of 0.6C), left for 10 days, and then charged to 0.3C equivalent (1.2A) at 2.45V. The constant current arrival time was measured. FIG. 4 shows the measurement result. Each battery was tested using three samples. From this figure, the lead-acid battery using the current collector of this example has a stronger adhesion between the current collector and the active material layer than the lead-acid battery using the conventional current collector, so the current collector and the active material layer It can be seen that lead sulfate is less likely to be generated at the interface with and the charge acceptance after leaving for over-discharge is improved.

In each of the above embodiments, the sheet material in which the red lead powder was embedded in the lead sheet was expanded to complete the current collector, but the current collector completed by other processes such as punching. Of course, the present invention can be applied to the body.

The constitutions of some of the inventions described in the specification will be shown below.

(1) A sheet made of lead or a lead alloy is used, and a high-level lead oxide (PbOx) is formed on the surface of the sheet.
: 1.13 ≦ X ≦ 2.0) A method for producing a current collector for a lead storage battery, in which powders or particles of 1.13 ≦ X ≦ 2.0) are dispersed and fixed so that the powders or particles are blasted on the surface of the sheet. Is formed into a plurality of recesses, the sheet having the plurality of recesses is passed through a tank in which the powders or particles are stored to fill the recesses with the powders or particles, and then the plurality of recesses are filled. A lead-acid battery current collector characterized in that a sheet in which recesses are filled with the powder or particles is passed between a pair of rolling rollers to be rolled, and the rolled sheet is used to manufacture the lead-acid battery current collector. Body manufacturing method.

(2) The lead oxide is red lead or α-Pb.
The method for producing a current collector for a lead storage battery according to (1), which is O ₂ .

(3) The average depth of the plurality of recesses is 2
The method for producing a lead storage battery current collector according to (1) above, wherein the current collector has a thickness of -15 μm.

(4) The method for producing a lead storage battery current collector according to (3) above, wherein the plurality of recesses are formed by being dispersed over 50 to 80% of the surface area of the surface of the lead storage battery current collector. .

(5) The method for producing a lead storage battery current collector according to (1), wherein the powder or particles have an average particle size of 5 to 20 μm.

[0026]

According to the present invention, high-grade lead oxide powder or particles are embedded in a sheet surface portion made of lead or a lead alloy so that most of its outer surface is covered with lead or a lead alloy. Therefore, the reaction area between the high-order lead oxide powder or particles and the sheet surface portion made of lead or lead alloy becomes large, and the high-order lead oxide powder when filling the current collector with the active material paste. Alternatively, the oxidation of the current collector by the particles is effectively promoted. Therefore, the current collector and the active material layer are brought into close contact with each other by aging for a short time, the conductivity between the current collector and the active material layer is increased, and the chemical conversion property and charge acceptability of the battery can be improved. Moreover, the high-grade lead oxide powder or particles are integrated with the active material layer, and the lead sheet is oxidized by the lead oxide powder to form an oxide layer at the interface between the lead oxide powder and the lead sheet. Because it is
The current collector and the active material layer can be effectively brought into close contact not only by the conventional so-called chemical action but also by the so-called physical action.

[Brief description of drawings]

FIG. 1 is a sectional view of a lead-acid battery current collector of the present embodiment.

FIG. 2 is a diagram showing how the lead-acid battery current collector of this example is manufactured.

FIG. 3 is a partial cross-sectional view of a positive electrode plate using the lead storage battery current collector of the present embodiment.

FIG. 4 is a view showing a charge acceptability test after leaving the lead storage battery used in the test for over-discharge.

[Explanation of symbols]

1 Lead sheet 2 Recessed portion 3 Lead red (Pb ₃ O ₄ ) powder

Claims (2)

[Claims] 1. A sheet made of lead or a lead alloy, wherein a high-level lead oxide (PbOx: 1.
(13 ≦ X ≦ 2.0) The current collector for a lead storage battery invading in a dispersed state of powder or particles, wherein the powder or particles are covered with the lead or the lead alloy on most of the outer surface thereof. A current collector for a lead storage battery, wherein the current collector is embedded in the surface portion. 2. A high-level lead oxide (PbOx: 1.) formed on a surface of a sheet made of lead or a lead alloy.
13 ≦ X ≦ 2.0) In the method for producing a lead storage battery current collector that bites in a state in which powder or particles are dispersed, in the surface of the sheet, a plurality of recesses for containing the powder or particles are formed, A lead storage battery current collector, characterized in that the plurality of recesses of the sheet are filled with the powder or particles, the sheet is rolled, and the rolled sheet is used to manufacture the lead storage battery current collector. Body manufacturing method.