JPS62150653A - Positive electrode plate of cladding type lead cell - Google Patents

Abstract

PURPOSE:To form a cladding type positive electrode plate with an excellent performance, by filling a slurry-form paste in a cladding type grid body with cylindrical tubes, and pressing the tubes to make rectangular forms. CONSTITUTION:Instead of filling lead powder in a cladding type grid body with cylindrical tubes, is filled a slurry-form paste 3 made by mixing and kneading lead powder or a mixture of lead powder and graphite with a large anisotropie, water, and a diluted sulfuric acid, and the tubes 1 are pressed to convert the form into rectangles. When the slurry-form paste 3 is filled, the tubes 1 get an adequate moisture and their forms can be converted easily. Furthermore, the paste is hardened as the tubes are in such a condition, the product is a plate-form cladding type positive electrode plate in appearance.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a positive electrode plate for a clad lead-acid battery (hereinafter referred to as a clad positive electrode plate).

Conventional technology and its problems The clad type positive electrode plate has a structure in which a lead alloy core is placed in the center of a porous cylindrical duplex made of glass fiber, acid-resistant, oxidation-resistant synthetic fiber, etc., and lead powder is used in the lattice body. It is manufactured by filling it with water and going through processes such as soaking and chemical conversion. Since the porous tube prevents the active material from falling off, it has a feature of longer life than a paste-type positive electrode plate.

Filling the tube with lead powder is performed while applying vibration.

However, since lead powder, which is a fine powder, has poor fluidity and is easily agglomerated, if the vibration is insufficient, a cavity is created in the tube that is not filled with lead powder. This tendency is more pronounced in large seed roots with long tubes, making it difficult to fill them with lead powder uniformly. If there is a hollow part in the tube, it is difficult for chemical conversion to proceed, resulting in unformed parts, which adversely affect the initial performance and RF life performance of the battery. On the other hand, if sufficient imaging is applied and lead powder is filled to prevent cavities from forming, the density of the active material will inevitably increase, resulting in poor active material utilization during discharge, and The problem was that the tube was damaged due to expansion.

Means for Solving the Problems The present invention eliminates the above-mentioned drawbacks and provides a clad type positive electrode plate with excellent performance. Instead of filling lead powder, the tube is filled with a slurry paste prepared by mixing lead powder or a mixture of lead powder and highly anisotropic graphite with water and dilute sulfuric acid. The purpose is to make the shape rectangular.

Example Examples of the present invention will be described below.

Water is added to ordinary lead powder and mixed well, and then the specific gravity is 1.
Gradually add 40% dilute sulfuric acid and mix well to obtain a Pb SO4 content of approximately 17% in dry state.

A slurry paste with a paste density of 192.9Q/ad was prepared from W4. This paste is called A. Next, a slurry paste B was prepared in exactly the same manner using a mixture of 1.0 wt % of highly anisotropic graphite having a particle size of 100 to 1200 μm and lead powder. These two types of paste were mixed into a tube with a diameter of 9IIIφ and a clad lattice body (^ size 10 [×
It was filled to a width of 10 arI). As shown in FIG. 2, the cross section of the clad positive electrode plate after filling is circular.

Note that 2 is a core metal, and 3 is a filled paste.

In the present invention, the filled electrode plate is pressed from both sides to form a tube into a rectangular shape as shown in FIG. When filled with slurry paste, the tube becomes moderately moist and its shape can be easily changed. Moreover, since the paste hardens in this state, it appears to be a clad positive electrode plate with a flat plate shape on top. This is not possible with conventional products that are filled with lead powder; in order to make the tube into a rectangular shape, it must be shaped in advance, which increases the number of man-hours and costs.

The clad type positive electrode plate prototyped in this way was heated to 2
After aging for 4 hours, a test battery having three positive electrodes and four negative electrodes was prepared by combining with a negative electrode plate having a sufficiently large capacity and weight.

The following table shows the results of 5-hour rate discharge and 30-minute rate discharge with the electrolyte specific gravity adjusted to 1.26 after initial charging.

Based on the present invention, batteries no. 1 and no. 2 are made by filling the tubes with slurry pastes A and B and then pressing the tubes into rectangular shapes. No. 3 and no. 4 are comparison products of no. 1 and no. 2, respectively, and the tubes are circular in shape. No. 5 is a conventional product filled with lead powder.

Table 1 Battery no. using a clad positive electrode plate according to the present invention.

1 and no, 2 is control battery no, 3, no,
The discharge performance is better than No. 4, and compared to the conventional products No. 5, the 5-hour rate capacity is about 10%, and the 30-minute rate capacity is 30 to 4.
It was also superior by 0%. This is because by making the tube rectangular, the distance between the electrodes is substantially shortened, which reduces the internal resistance of the battery and improves the utilization rate of the positive electrode active material. In battery no. 2 using slurry paste B prepared by adding highly anisotropic graphite to lead powder,
The effect has become even more pronounced.

Effects of the Invention As detailed above, according to the present invention, it is possible to improve the discharge performance of a clad type battery, especially by changing the spacing between the core metals, the tube diameter, and the tube pressing force after filling the slurry paste. Since the thickness of the clad type regular i-plate can be made thinner, further performance improvement can be expected. In addition, the slurry paste can be filled in a short time, which simplifies the electrode plate manufacturing process, and it has the advantage of not generating harmful lead dust, so it has great industrial value.

[Brief explanation of drawings]

FIG. 1 shows a cross section of a clad type regular m1fi according to the present invention, and FIG. 2 shows a conventional product.

Claims (1)

[Claims] 1. A positive electrode plate for a clad lead-acid battery, characterized in that a clad lattice body comprising a cylindrical tube is filled with a slurry paste, and the tube is pressed into a rectangular shape. 2. The positive electrode for a clad lead-acid battery according to claim 1, wherein the slurry paste is a paste prepared by kneading lead powder or a mixture of lead powder and highly anisotropic graphite with water and dilute sulfuric acid. Board.