JPS6224555A - Manufacture of positive plate for clad type lead-acid battery - Google Patents

Abstract

PURPOSE:To shorten soaking time, increase the generation of lead sulfate inside a active material filling layer,and increase active material utilization in a positive electrode by soaking a clad type positive substrate in a dilute sulfuric acid solution, to which a small amount of anion surfactant is added, filled in a soaking bath. CONSTITUTION:A clad type positive substrate is formed by connecting core metals with a lead alloy lateral frame. The substrate is soaked in dilute sulfuric acid, to which a small amount of anion surfactant is added, filled in a soaking bath. The addition of 0.5wt% or more of anion surfactant is effective, and the generation of lead sulfate inside an active material filling layer is increased with the addition of the surfactant from 0.5wt% to about 2wt%. After 10min soaking, the substrate is dried by a usual method to obtain a non-formed positive substrate. By applying formation to the substrate, A positive electrode is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application) The present invention relates to a method for manufacturing a positive electrode plate for a clad lead-acid battery.

(Conventional technology) The conventional manufacturing method for positive electrode plates for clad lead-acid batteries involves manufacturing a large number of cylindrical bodies in which raw material powder such as lead powder is filled into the gap between a lead alloy core and a glass fiber tube around the core. A positive electrode substrate consisting of a book is simply immersed in dilute sulfuric acid in a soaking tank for a required period of time, dried to obtain an unformed plate, and then chemically formed.

(Problems to be Solved by the Invention) In the conventional method described above, simply immersing the positive electrode substrate in dilute sulfuric acid requires a long time to generate the required amount of lead sulfate; Core metal a and tube b as shown
The production rate of lead sulfate at each part of the active material packed layer 0 in the thickness direction between The production rate is significantly lower. In addition, when a positive electrode substrate with a right-hand curve IIA due to the uneven production of lead sulfate is used as a positive electrode, the active material utilization rate of each part in the thickness direction of the active material filling layer is shown in the distribution plane in Figure 2. As shown in 1jle, it has the disadvantage that it deteriorates significantly, especially in the inner part of the layer.

(Means for Solving the Problems) The present invention improves the drawbacks of the conventional method described above, shortens the soaking treatment time, improves the lead sulfate production rate especially in the inner part of the active material packed layer, and uses it as a positive electrode. The present invention provides a method for manufacturing a positive electrode plate for a clad lead-acid battery that can increase the active material utilization rate when A clad positive electrode substrate consisting of a large number of filled cylinders is immersed in dilute sulfuric acid in a soaking tank.1 This method is characterized in that it is immersed in dilute sulfuric acid to which a small amount of anionic surfactant is added.

(Function) According to Kenpo, since a small amount of anionic surfactant is added to dilute sulfuric acid, it can easily penetrate into the inner part of the active material packed layer in each cylinder, and lead sulfate in this part can be easily absorbed. leads to a uniform lead sulfate production curve throughout the thickness.

(Example) Examples of the present invention will now be described.

As in the conventional method, a porous tube made of glass fiber or the like is inserted from above into each of the multiple parallel lead alloy core metals that protrude upward from the lower horizontal rod of the lead alloy so that a cylindrical void exists around the outer periphery of the core metal. 1.Make a large number of cylinders by filling the desired amount of raw material powder such as lead powder into the gaps, completely sealing the upper surfaces of these cylinders, and connecting each core metal with the upper crossbar of the arrow lead alloy. A gold clad positive electrode substrate is prepared. Next, this substrate is immersed in dilute sulfuric acid in a soaking tank. In this case, according to the invention, immersion is carried out in dilute sulfuric acid to which a small amount of anionic surfactant is added. It is effective at an addition amount of 5% by weight or more, and the amount of lead sulfate produced inside increases as the addition amount increases up to 2wt. is effective, but no increase in the effect of addition is observed, so economically it is preferable to limit the amount added to about 2% by weight.

After 10 minutes of immersion, the substrate was pulled out and dried in a conventional manner to obtain an unformed positive electrode substrate. The results of examining the production rate of lead sulfate at each part in the thickness direction of the active material filled layer of each cylinder of this positive electrode substrate are shown in FIG. 3. In the drawing (
1) shows an active material filled layer with a thickness of Seag filled between a core bar (2) and a glass fiber tube (3). Production rate t of lead sulfate at each part in the thickness direction of the packed bed (1)
- As shown by the right curve laA of the measured result,
The production rate of lead sulfate in the core metal 123 m of the packed bed (1), that is, in its inner part, is significantly improved compared to the conventional soaking method shown in NX1, and even in the entire thickness direction. Extremely favorable lead sulfate production rate SO ~ 40%
It can be seen that a fairly uniform production distribution can be obtained. In the case of the conventional method shown in figure f41, dilute sulfuric acid (specific gravity 1.1) is used at the same concentration as in Kempo.
0), it can be seen that the soaking treatment of Kempo significantly shortens the treatment time to generate the required amount of lead sulfate.

When the above positive electrode substrate obtained by Kenpo is chemically converted and used as a positive electrode of a battery, the active material filling layer (1
The active material utilization rate of each part in the thickness direction of No. 1 is as shown in FIG. That is, as shown by the distribution plane IsB, it can be seen that the active material utilization rate is high even in the inner part of the filled layer (1). Comparing this with the extremely low utilization rate of the inner part of the active material filled layer C when a soaking-treated product as shown in the conventional method @2 is used as a positive electrode of a battery, it is found that the utilization rate of the inner part of the active material filled layer C is significantly improved. I understand.

Example 1 A large number of positive electrode substrates each consisting of a large number of cylindrical bodies filled with a desired amount of lead powder containing 30% metallic lead in the cylindrical gap between the glass fiber tube and the cored metal were placed in each soaking bath. Inside,
Dilute sulfuric acid with a specific gravity of 1.10 and a surfactant such as 0.2
%, Q, 5%, 2%, 5% and dilute sulfuric acid with a specific gravity of 1.10 without adding a surfactant according to the conventional method for 10 minutes, and then air-dried. Obtain a chemically formed board. For each positive electrode substrate, the nominal s O
Ah/s HR clad lead-acid batteries were prepared, and their respective battery capacities were tested in relation to the amount of anionic surfactant added. The relationship was as shown in the table below. The battery capacity according to the conventional method (discharge time: 5 hours and 12 minutes) was set to t-100.

In this way, in the soaking process, the capacity of a battery using a positive electrode substrate obtained by soaking in dilute sulfuric acid to which a surfactant has been added as in the present method is lower than that obtained by simply soaking in dilute sulfuric acid using the conventional method. It was also observed that the battery capacity was increased compared to a battery using a positive electrode substrate.

(Effects of the Invention) According to the present invention, when manufacturing a clad type positive electrode, the positive electrode substrate material is immersed in dilute sulfuric acid to which a small amount of surfactant has been added, so that the required amount can be obtained in a short time. The production of lead sulfate has the effect of producing a high amount of lead sulfate on the core metal side of the active material packed layer in each cylinder, that is, on the inner side, and the capacity of the battery using this increases accordingly. It has the following effects.

[Brief explanation of the drawing]

Figure 1 is a graph showing the production rate of lead sulfate at each part in the thickness direction of the active material filled layer produced by the conventional method. Figure 2 is the thickness of the active material filled layer of a battery using the positive electrode substrate manufactured by the conventional method as the positive electrode. A graph showing the active material utilization rate of each part in the horizontal direction,
Figure 5 is a graph showing the production rate of lead sulfate in each part in the thickness direction of the active material filled layer by this method, and Figure 4 is the active material filling of a battery using the positive electrode substrate manufactured by this method as the positive electrode. It is a graph showing the active material utilization rate of each part in the thickness direction of the layer. A... Lead sulfate production distribution curve B... Active material utilization rate curve

Claims (1)

[Claims] 1. A clad positive electrode substrate consisting of a large number of cylinders filled with raw material powder such as lead powder in the gap between a core metal and a porous tube on its outer periphery is soaked in dilute sulfuric acid in a soaking tank. A method for producing a positive electrode plate for a clad lead-acid battery, which comprises immersing it in dilute sulfuric acid to which a small amount of anionic surfactant is added. 2. The manufacturing method according to claim 1, wherein the amount of the ionic surfactant added is about 0.5 to 2%.