JPH06223864A - Lead-acid battery - Google Patents

Abstract

PURPOSE:To obtain a lead-acid battery, in which the diffusing property of electrolyte in the surface of a plate is improved and the adhesiveness of plates to a separator is improved and a fall of the active material from a grid is prevented and the battery capacity can be realized sufficiently. CONSTITUTION:A positive plate 1, both surfaces of which support an active material protecting layer 3a, and a negative plate 2, both surfaces of which support an active material protecting layer 3b, are used. These plates 1, 2 are separated by a separator 4 to form a plate group, and this plate group is housed inside of a battery jar together with the electrolyte to form a lead-acid battery. The active material protecting layers 3a, 3b are made of acid resistant fiber having a porosity larger than the porosity of the plates 1, 2 and including the active material. The active material of the active material protecting layers 3a, 3b and the active material of the plates 1, 2 corresponding to the active material of the layers 3a, 3b are unified into one body.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a lead storage battery using an electrode plate having an active material protective layer supported on the surface thereof.

[0002]

2. Description of the Related Art An electrode plate group, which is a power generating element of a lead storage battery, is constructed by laminating an anode plate and a cathode plate with a separator interposed therebetween.

As a conventional electrode plate of this type of lead acid battery,
It is configured by holding an active material in a lattice body such as a cast lattice body, an expanded lattice body, and a punched lattice body. In order to prevent the active material from falling off, the grid body is filled with a highly viscous paste-like non-active material having a viscosity of 1,000,000 cps or more.
Further, in a grid body having a large aperture ratio such as an expanded grid or a punched grid, since the paste holding power is low, the active material protective layer made of paste paper or glass fiber is brought into contact with the surface of the electrode plate after the paste is filled so that the active material We are trying to prevent falling. Then, after that, the active material layer is formed through the aging, drying and chemical conversion steps of the electrode plate.

[0004]

However, in the conventional electrode plate, it is necessary to suppress the porosity of the active material within 65% in order to prevent the active material from falling off. Therefore, the conventional electrode plate has a sufficient porosity. However, there is a problem in that the lead storage battery cannot have a high capacity because it cannot obtain a high degree. This is because in a lead-acid battery with a small amount of electrolyte, such as a sealed lead-acid battery, if the porosity of the active material is small, the electrolyte does not sufficiently diffuse,
This is because the electrolytic solution reacts only with the active material on the surface of the electrode plate, and the active material on the surface of the electrode plate is converted to lead sulfate at the end of discharge to block the pores. In such a state, the high rate discharge characteristic of the lead storage battery deteriorates, and the battery capacity significantly decreases.

Therefore, in order to increase the porosity of the electrode plate, there has been proposed a lead-acid battery using an electrode plate in which a grid is filled with a soft paste produced by increasing the amount of water. The plate has a problem that the strength of the active material is weak.

Further, there has been proposed an electrode plate in which an active material protective layer made of paste paper or glass fiber is pressure-bonded to the surface of the electrode plate in order to prevent the active material from falling off. However, when the active material protective layer is simply pressure-bonded to the surface of the electrode plate, the adhesion between the electrode plate and the active material protective layer may be poor at the part where the electrode plate is present, and not only the active material may fall off. In a battery manufactured using such an electrode plate, the electrolytic solution is not sufficiently diffused from the electrolytic solution holder to the electrode plate, resulting in a decrease in capacity and a large variation. Furthermore, since the active material protective layer made of paste paper or glass fiber does not have conductivity, there is a problem that the current collecting efficiency of the electrode plate cannot be increased.
Further, when an acid-soluble material such as cellulose is used as the paste paper, there is a problem that hydrogen overvoltage is reduced, and charge / discharge cycle life and float life are reduced.

The object of the present invention is to improve the diffusivity of the electrolyte solution to the surface of the electrode plate, improve the adhesion between the electrode plate and the separator, prevent the active material from falling off from the grid, and ensure a sufficient battery capacity. It is to provide a lead storage battery that can be developed.

[0008]

The constitution of the present invention which achieves the above object will be described as follows.

The present invention according to claim 1 uses a positive electrode plate and a negative electrode plate each having an active material protective layer supported on both sides thereof, and these electrode plates are separated by a separator. In the lead-acid battery in which the active material protective layer is housed together with an electrolytic solution in the battery case, the active material protective layer is composed of acid resistant fibers having a porosity higher than that of the electrode plate and containing an active material, The active material of the layer and the active material of the electrode plate are integrated.

According to a second aspect of the present invention, the content of the active material in the active material protective layer according to the first aspect is 5% by weight.
It is characterized in that it is not less than 70% by weight.

[0011]

In the electrode plate having such an active material protective layer, after filling the grid with paste, a thin paper-like active material protective layer made of acid resistant fiber containing lead or lead oxide is formed on the electrode plate surface. It is formed by abutting and forming.

The electrode plate thus obtained has a structure having a porosity higher than that of the electrode plate and an active material protective layer containing an active material integrally formed on the surface.

In a lead storage battery using such an electrode plate, the active material on the electrode plate surface is not blocked even at the end of discharge,
The diffusivity of the electrolytic solution is improved.

Further, by integrating the active material of the electrode plate and the active material in the active material protective layer on the surface thereof during aging and chemical formation, the active material holding power is enhanced and the active material can be prevented from falling off, and the separator can be separated. Since the acid-resistant fibers of the active material protective layer that are in contact with each other are entangled with each other under pressure, their adhesion is good. Therefore, the adhesion between the active material of the electrode plate, the active material protective layer containing the active material, and the separator is significantly improved.

Further, the active material protective layer in contact with the surface of the electrode plate also contains the active material, so that the active material utilization rate is improved and the capacity is sufficiently exhibited.

When the content of the active material in the active material protective layer is 5% by weight or more and 70% by weight or less, the capacity of the lead storage battery can be surely improved.

[0017]

EXAMPLE FIG. 1 is a sectional view of an electrode plate group using the electrode plate of this example. In the figure, 1 is an anode plate, 2
Is a cathode plate, 3 a is an active material protective layer integrally provided on both surfaces of the anode plate 1, and 3 b is an active material protective layer integrally provided on both surfaces of the cathode plate 2. These active material protective layers 3a and 3b are made of acid resistant fibers having a porosity higher than that of the electrode plates 1 and 2 and containing an active material. The active material in the active material protective layers 3a and 3b and the active material of the electrode plates 1 and 2 are integrated. 4 is a separator made of acid resistant fiber. The separator 4 includes an anode plate 1 and a cathode plate 2
And active material protective layers 3a and 3b between them.

In the case of this embodiment, the active material protective layers 3a and 3b are provided.
As the material, a glass fiber containing 50% by weight of lead monoxide powder so as to have a porosity of 70% was mixed and produced. An anode plate 1 having such an active material protective layer 3a,
The cathode plate 2 having the active material protective layer 3b is filled in a grid with paste, and the active material protective layer 3a or 3b is pressure-bonded to both surfaces thereof and then aged. By doing so, the non-activatable active material in the paste of the electrode plates 1 and 2 and the lead monoxide in the active material protective layers 3a and 3b are bonded. Next, when formation is performed, the anode plate 1
The lead monoxide in the active material protective layer 3a press-bonded to both surfaces of PbO ₂ changes to PbO ₂ , and the lead monoxide in the active material protector 3b pressed to both surfaces of cathode plate 2 changes to Pb. It becomes the same material as the active material of the electrodes 1, 2. This improves the adhesion between the electrode plates 1 and 2 and the active material protective layers 3a and 3b,
There was no peeling between the electrode plates 1 and 2 and the active material protective layers 3a and 3b and no space.

Next, the active material protective layers 3a and 3b of the present embodiment.
(2V-1.5 Ah) lead-acid battery (referred to as the product of the present invention) that incorporates the electrode plate group having the structure shown in FIG. Built-in electrode plate group using electrode plates that are crimped on both sides (2V-1.
5 Ah) Lead acid batteries (referred to as conventional products) were manufactured, and the capacity ratios of these lead acid batteries were measured. The lead-acid battery of the present invention and the lead-acid battery of the conventional product have a grid and a separator of the same shape, and the electrode plate size and the like of each battery are also the same.

FIG. 2 shows the capacity measured by discharging each battery under the conditions of 1 CA discharge, final voltage of 1.6 V, and ambient temperature of 25 ± 2 ° C. In the figure, the vertical axis shows the capacity ratio when the capacity of the conventional product is 100. From FIG. 2, it is understood that the lead storage battery using the electrode plates 1 and 2 of the present invention has a capacity ratio improved by about 20% as compared with the lead storage battery using the conventional electrode plate. The product of the present invention has an improved capacity ratio because the active material protective layer made of paste paper only prevents the active material from falling off in the conventional product, and the active material protective layer made of the paste paper is used. Is because it has no electrical conductivity and therefore contributes little to the increase in capacity and current collection efficiency. On the other hand, the lead-acid battery using the electrode plates 1 and 2 of the present invention not only prevents the active material from falling off and improves the adhesiveness, but also greatly contributes to the capacity increase.

FIG. 3 shows the content of the active material in the active material protective layers 3a and 3b contacting the surfaces of the electrode plates 1 and 2, the capacity of the lead storage battery and its variation. FIG. 3 shows the capacity ratio when the average capacity is 100 when the content of the active material is 0% by weight.

As is clear from FIG. 3, increasing the content of the active material in the active material protective layers 3a and 3b reduces the variation in capacity and further increases the average capacity. This is the electrode plates 1 and 2 and the active material protective layer 3a,
This is because the adhesion with 3b is improved and the variation is reduced. Further, according to the present invention, since the porous active material layer is provided on the surfaces of the electrode plates 1 and 2 by the active material protective layers 3a and 3b, the capacity of the lead storage battery is also increased. However, when the content of the active material in the active material protective layers 3a, 3b exceeds 70% by weight, the porosity of the active material protective layers 3a, 3b becomes small and the capacity of the lead storage battery decreases, so The content of the substance is preferably 5% by weight or more and 70% by weight or less.

The types and shapes of the lead oxide and the separator forming the active material protective layers 3a and 3b on the surface of the electrode plate and the content of the lead oxide are not limited to those shown in the examples, and the acid-resistant fibers are carbon or carbon. It may be graphite fiber or the like, or may be made of an inorganic or organic material.

[0024]

As described above, according to the lead storage battery of the present invention, the following effects can be obtained.

(A) The active material protective layer having a higher porosity than that of the active material of the electrode plate is present on the surface of the electrode plate. Therefore, the diffusion property of the electrolytic solution on the surface of the electrode plate can be improved. .

(B) Since the active material protective layer containing the active material and the active material of the electrode plate are integrated, the active material holding power of the electrode plate is enhanced and the active material of the electrode plate can be prevented from falling off.

(C) Since the acid resistant fibers in the separator and the acid resistant fibers of the active material protective layer are entangled with each other, the adhesion is improved and the variation in capacity can be reduced.

(D) Since the active material protective layer integrated on the surface of the electrode plate also has the active material, the utilization ratio of the active material is improved and the capacity can be sufficiently exhibited.

(E) Therefore, according to the lead storage battery using the electrode plate of the present invention, a lead storage battery having a high capacity can be obtained.

By setting the content of the active material in the active material protective layer (F) to 5% by weight or more and 70% by weight or less, the capacity of the lead storage battery can be reliably improved.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view showing an electrode plate group of a lead storage battery using the electrode plate of the present embodiment.

FIG. 2 is a comparison diagram showing a capacity ratio between a lead storage battery using the electrode plate of the present embodiment and a lead storage battery using a conventional electrode plate.

FIG. 3 is a diagram showing variations in content and capacity of the active material contained in the active material protective layer on the surface of the electrode plate, and a capacity ratio.

[Explanation of symbols]

 1 Anode plate 2 Cathode plate 3a Active material protective layer containing active material 3b Active material protective layer containing active material 4 Separator

Claims (2)

[Claims] 1. An anode plate and a cathode plate each having an active material protective layer supported on both sides are used, and an electrode plate group constituted by separating these electrode plates with a separator is placed in a battery case together with an electrolytic solution. In the accommodated lead acid battery, the active material protective layer is composed of acid-resistant fibers having a porosity higher than that of the electrode plate and containing an active material, and the active material of the active material protective layer and the electrode plate. Lead acid battery characterized by being integrated with the active material of. 2. The lead acid battery according to claim 1, wherein the content of the active material in the active material protective layer is 5% by weight or more and 70% by weight or less.