JP3339080B2 - Anode plate for lead storage battery and method of manufacturing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an anode plate for a lead storage battery and a method for producing the same.

[0002]

2. Description of the Related Art A conventional anode plate for a lead storage battery is manufactured as follows. First, an active material paste is prepared by mixing lead monoxide powder, dilute sulfuric acid and water, and this active material paste is filled into a lead or lead alloy current collector to prepare a wet electrode plate. next,
The undried electrode plate is aged and dried to produce tribasic lead sulfate in the active material, and then subjected to chemical conversion to produce a lead storage battery anode plate. When only lead monoxide powder is used as a raw material of the active material paste, there is a problem that it takes at least 3 to 4 days to complete an electrode plate through aging, drying and chemical formation. Therefore, a kneaded material obtained by kneading lead oxide mainly composed of leadtan (trilead tetroxide) and water, or a kneaded material kneaded lead oxide mainly composed of leadtan and dilute sulfuric acid is used as an active material paste. It was proposed to use. Lead mushrooms react with sulfuric acid during chemical formation without aging, and lead dioxide (P
In addition to generating bO ₂ ), the theoretical amount of electricity required for chemical formation is also reduced by about 65% as compared with an electrode plate using lead monoxide powder as a raw material of an active material paste. Therefore, when such a kneaded material is used as an active material paste, a lead storage battery anode plate having high conversion efficiency can be manufactured in a short time.

[0003]

However, an undried electrode plate in which an active material paste obtained by kneading leadtan with water is filled in a current collector, has a surface portion which is easily contacted with an electrolytic solution (dilute sulfuric acid) during chemical formation. Although the formation efficiency is high, the formation efficiency inside the electrode plate is low because it takes time for sulfuric acid to penetrate inside the electrode plate. FIG. 7 shows a plurality of 2V-2Ah batteries formed using electrode plates having different thicknesses formed under the same conditions (formed in a low-density sulfuric acid solution at a charge amount of 250%). FIG. 4 is a diagram illustrating a relationship between a plate thickness and a discharge time. As shown in FIG. 7, it can be seen that the thicker the electrode plate, the more difficult it is to form the inside, and the shorter the discharge time (the lower the initial capacity). In addition, since the active material paste obtained by kneading lead red with water as described above has a low viscosity, water is easily released. Therefore, when the active material paste is filled or dried, the active material shrinks, and the porosity is reduced. As a result, there is a problem that the capacity is reduced.

When an active material paste obtained by kneading lead ginseng with dilute sulfuric acid is used instead of kneading with water, the bonding force between lead dioxide and lead sulfate formed by the reaction between dilute sulfuric acid and ginseng. Is weak, the bonding force between the active materials is not sufficiently increased, and there is a problem that the life of the battery is shortened.

An object of the present invention is to provide a positive electrode plate for a lead-acid battery having a high capacity and a long life, and a method for producing the positive electrode plate for a lead-acid battery in a short time by increasing the formation efficiency.

[0006]

According to the first aspect of the present invention, a collection
Fill the conductor with the active material paste to make an undried electrode plate.
After drying the undried electrode plate of
Tribasic lead sulphate and lead tan
The active material paste obtained by kneading water and water
Mixing the process of forming the side-active material paste layer with lead red and water
Fill the kneaded active material paste on the inner active material paste layer
Filling to form the outer active material paste layer
Manufacture undried plates. The invention of claim 2 is the invention of claim 1
To specify the crystal structure of the anode plate manufactured by the method of the invention
And a positive electrode for a lead storage battery in which an active material is held on a current collector.
The size of each part of the active material is less than 1μm
Prismatic lead dioxide (made of lead-tin)
Is tabular lead dioxide (made from tribasic lead sulfate
), An inner active material layer having a crystal structure in which
It has a prismatic lead dioxide crystal structure with a size of 1 μm or less.
And an outer active material layer.

[0007]

According to the method of the first aspect of the present invention, an active material paste layer composed of an active material paste obtained by kneading tribasic lead sulfate, lead ginseng and water is used as an inner active material paste layer, and on the outside thereof, lead ginseng and water are placed. And an outer active material paste layer made of an active material paste obtained by kneading the above. Since the outer active material paste layer does not significantly suppress the diffusion of the electrolyte into the electrode plate, according to the present invention, the capacity can be increased and the formation efficiency can be improved. In addition, the active material paste obtained by kneading lead red with water fills a smooth surface such as a current collector, causing the active material to shrink and reduce the porosity. Is filled in an uneven portion, the active material paste enters into the uneven portion, so that the active material does not shrink and the porosity does not decrease.

According to the second aspect of the present invention, the size of each part is 1
An inner active material layer having a crystalline structure in which spherical or flat lead dioxide is bonded to prismatic lead dioxide having a diameter of 1 μm or less, and an outer active material layer having a prismatic lead dioxide crystal structure having a dimension of 1 μm or less. When the active material is formed from the above, the inner active material layer has a higher bonding strength, and the outer active material layer has a higher permeability of the electrolyte, so that a long-life, high-capacity battery can be obtained.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail.

Example 1 In this example, an anode plate for a lead storage battery was manufactured as follows.

First, a specific gravity of 1.2 kg was added to 0.8 kg of lead monoxide powder.
203.6 ml of sulfuric acid of No. 6 was added and kneaded to prepare tribasic lead sulfate. Next, 0.9 g of the tribasic lead sulfate and 2.1 g
kg and 320 ml of water were kneaded to prepare an active material paste, and the active material paste was filled into a current collector comprising a grid of lead alloy to form an active material paste layer having a thickness of 2.5 mm.
The preferred weight range of the tribasic lead sulfate with respect to the lead was 20 to 40%, and in this example, 30% by weight. When the undried electrode plate is dried and then subjected to chemical formation at a charge amount of 300%, the active material paste layer is converted into a prismatic lead dioxide (made of lead tin) having a dimension of 1 μm or less in a spherical or flat plate. The active material layer has a crystal structure in which lead dioxide (made of tribasic lead sulfate) is bonded.

Next, in order to investigate the characteristics of the anode plate for a lead storage battery manufactured by the method of the present embodiment, four types of anode plates a1 to d were used.
1 and tested. The anode plate a1 is the anode plate of this embodiment. The anode plate b1 is composed of 3 kg of lead monoxide powder and a specific gravity of 1.26.
Is a conventional anode plate manufactured using an active material paste obtained by mixing 373 ml of diluted sulfuric acid with 300 ml of water. Anode plate c1
Is 3.5kg of lead red, 1.5kg of lead monoxide powder and 865.
This is a conventional anode plate manufactured using an active material paste kneaded with 8 ml of an active material. The anode plate d1 is a conventional anode plate manufactured using an active material paste obtained by kneading 2.1 kg of lead red, 0.8 kg of lead monoxide powder, 203.6 ml of dilute sulfuric acid having a specific gravity of 1.26 and 320 ml of water. The weight of the active material in each of the anode plates a1 to d1 is the same. Using the anode plates a1 to d1, 4Ah-6V type batteries A1 to D1 were manufactured, and the initial capacity and cycle life characteristics of each of the batteries A1 to D1 were examined. The initial capacity of each battery is 25 ± 1 ° C ambient temperature,
Discharge was performed at 0.25 CA (final voltage: 1.7 V), and the discharge time was measured. The cycle life characteristic of each battery was 0.25.
After discharging at CA (final voltage 1.75 V), the battery was left for 1 hour, and then charged and discharged at 2.45 V (limited current 0.3 CA) for 6 hours. Table 1 shows the battery B using the conventional anode plate b1.
The ratio of the characteristics of each battery when the performance of No. 1 is 100% is shown. Table 1 also shows the ratio of the production time of each battery.

[0013]

[Table 1] From this table, it can be seen that in the battery C1 using the conventional anode plate c1, since the active material paste easily releases water, the porosity of the active material layer is reduced and the initial capacity of the battery is reduced. Also, it can be seen that the cycle life characteristic of the battery D1 using the conventional anode plate d1 is deteriorated because the bonding force between the active materials is weak. In contrast to these batteries, the battery A1 using the anode plate a of the present embodiment has an initial capacity of 19%, a cycle life characteristic improved by 90%, and a manufacturing time of 40% compared to the battery B1 using the conventional anode plate b1. You can see that it is decreasing.

FIG. 1 shows the relationship between the weight ratio of the tribasic lead sulfate to the lead and the initial capacity ratio of the battery made using the active material paste having the weight ratio. This test was carried out using a battery manufactured by changing the weight ratio of tribasic lead sulfate to lead in the manufacturing method of the present embodiment. In this figure, the initial value of the battery B1 using the conventional anode plate b1 is shown. 100% capacity
And According to this figure, when the weight ratio of tribasic lead sulfate to lead is more than 40%, the conversion efficiency is reduced and the initial capacity ratio is reduced. When the weight ratio is less than 20%, the viscosity of the active material paste is reduced. It can be seen that the porosity of the active material decreases and the capacity decreases.

Next, the battery used for the measurement of FIG. 1 was repeatedly charged and discharged to examine the relationship between the weight ratio of tribasic lead sulfate to lead and the cycle life ratio of the battery. FIG. 2 shows the measurement results. In this figure, the cycle life of the battery B1 using the conventional anode plate b1 was set to 100%.
From this figure, the weight ratio of tribasic lead sulfate to lead red is 20 to
It can be seen that when it is 40%, the cycle life characteristics are improved by about 90% as compared with the battery B1 using the conventional anode plate b1. When the weight ratio is less than 20%, the bonding force between the active materials is reduced, and the cycle life characteristics are reduced. When the weight ratio exceeds 40%, lower oxides (PbO _x ) due to poor conversion increase and cycle life characteristics deteriorate.

Next, a prismatic PbO for forming an active material layer is formed.
FIG. 3 shows the relationship between the average length of No. ₂ and the initial capacity ratio of the battery having the active material layer. In this figure, the cycle life characteristic of a battery having an average PbO ₂ length of 1 μm is 100%.
The anode plates having different average lengths of prismatic PbO ₂ were produced by changing the size of lead and the formation conditions extremely. From this figure, it can be seen that when the average length of PbO ₂ exceeds 1 μm, the contact area (bonding area) between the crystals becomes small, the bonding strength of the active material layer is reduced, and the cycle life characteristic is reduced.

FIG. 4 shows the relationship between the specific surface area of the active material layer and the initial capacity ratio of a battery having the active material layer having the specific surface area. In this figure, the initial capacity of a battery having an active material layer having a specific surface area of 5 m ² / g was set to 100%, and anode plates having different active material layer specific surface areas were prepared by changing formation conditions. From this figure, it can be seen that when the specific surface area of the active material layer is less than 10 m ² / g, the reaction area between the active material and the electrolyte decreases, and the capacity of the battery decreases.

Example 2 In this example, an anode plate for a lead storage battery was manufactured as follows.

First, an active material paste is prepared by kneading tribasic lead sulfate, lead tin and water in a weight ratio of 10: 10: 3, and this active material paste is filled in a current collector comprising a grid of lead alloy. As a result, an inner active material paste layer having a thickness of 1.5 mm was formed.
The used tribasic lead sulfate was 1.260 in specific gravity with lead oxide.
And sulfuric acid at a weight ratio of 3: 1. Next, an active material paste is prepared by kneading a 20: 3 weight ratio of lead red and water, and the active material paste is filled on the inner active material paste layer to form a 0.75 mm thick outer active material paste layer. Was formed to produce a 3 mm-thick wet electrode plate. The preferable weight range of the tribasic lead sulfate with respect to the lead in the entire active material paste is 20 to 40%. When the undried electrode plate is dried and then subjected to chemical formation at a charge amount of 300%, the inner active material paste layer becomes spherical or flat on prismatic lead dioxide (made of lead tin) having a dimension of 1 μm or less. Lead oxide (made from tribasic lead sulfate) in the form of an inner active material layer with a combined crystal structure,
The outer active material paste layer is an outer active material layer having a prismatic lead dioxide (made of lead-tin) crystal structure having a dimension of 1 μm or less in each part. When the electrode plate was manufactured by the method of the present example, the manufacturing time could be reduced by about 60% as compared with the case where the electrode plate was manufactured using an active material paste in which lead monoxide powder, dilute sulfuric acid and water were mixed. .

[0020] Then in order to investigate the characteristics of the anode plate for a lead storage battery prepared by the method of this embodiment, the anode plate of the four types of a2 to d
2 and tested. The anode plate a2 is the anode plate of this embodiment. The anode plate b2 is an anode plate of another embodiment in which the active material layer is entirely formed of an inner active material paste layer (an active material paste obtained by kneading lead tribasic sulfate, lead tin and water). The anode plate b2 has the same configuration as the anode plate of the first embodiment except for the thickness of the electrode plate. The anode plate c2 is a conventional anode plate manufactured using an active material paste obtained by mixing lead monoxide powder, diluted sulfuric acid and water. The anode plate d2 is a conventional anode plate manufactured using an active material paste obtained by kneading only lead and water. Each of the anode plates a2 to d2 is a 3 mm-thick electrode plate in which the same amount of active material paste is filled in a current collector, and each of the anode plates a2 to d2 has the same configuration except for the active material paste. I have. Using the anode plates a2 to d2 and the cathode plates having the same configuration, batteries 2A to D2 of 2V-2Ah are made, and the battery A2
-D2 was formed in a low specific gravity sulfuric acid solution at a charge of 300%, and then discharged at 1 CA to measure the discharge time of each battery A2-D2. The measurement results show that the battery A2 using the anode plate a2 of this embodiment had a discharge time of 45 minutes, while the battery B2 using the anode plate b2 of the other embodiment had a discharge time of 4 minutes.
3 minutes, battery C using conventional anode plates c2 and d2
2 and D2 each had a discharge time of 40 minutes. From this measurement result, it can be seen that the use of the anode plate a2 of this embodiment can provide a battery with higher formation efficiency and higher initial capacity than the conventional anode plates c2 and d2.

Next, the batteries A2 to D2 were subjected to chemical formation while changing the amount of power applied thereto, and were discharged. The relationship between the amount of power applied to each of the batteries A2 to D2 and the discharge time was measured. FIG. 5 shows the measurement results. From this figure, it can be seen that the anode plate a2 of this embodiment has a higher conversion efficiency (discharge time is longer at the same charge amount) than the anode plate b2 of the other embodiments and the conventional anode plates c2 and d2.

Next, the batteries A2 to D2 were charged at 0.25 CA to a final voltage of 1.75 V, allowed to stand for 1 hour, and then charged and discharged at 2.45 V and a limited current of 0.9 CA for 4 hours. The cycle life characteristics of A2 to D2 were examined. FIG. 6 shows the measurement results. From this figure, the battery A2 using the anode plate a2 of this embodiment has a longer life than the battery B2 using the anode plate b2 of another embodiment and the batteries C2 and D2 using the conventional anode plates c2 and d2. I understand. Particularly, as compared with the battery D2 using the anode plate d2 of the comparative example using only lead red as an active material, the life of the battery A is extended by 200%.

[0023]

According to the first aspect of the present invention, tribasic sulfuric acid
Active material consisting of active material paste obtained by kneading lead, lead red and water
Material paste layer as the inner active material paste layer,
Electrode plates to provide an outer active material paste layer that does not contain sulfuric acid
When the thickness of the electrode is increased, diffusion of the electrolyte into the electrode plate is large.
Battery formation efficiency can be improved
You. According to the invention of claim 2 , an inner active material layer having a crystal structure in which spherical or flat lead dioxide is bonded to prismatic lead dioxide having dimensions of 1 μm or less, and a corner having a dimension of 1 μm or less. Since the active material is composed of the outer active material layer having a columnar lead dioxide crystal structure, the inner active material layer has a higher bond strength, and the outer active material layer has a higher electrolyte permeability, so that the longer the active material layer is, the longer the active material layer becomes. A long-life, high-capacity battery can be obtained.

[Brief description of the drawings]

FIG. 1 is a diagram showing the relationship between the weight ratio of tribasic lead sulfate to lead and the initial capacity ratio of a battery.

FIG. 2 is a graph showing the relationship between the weight ratio of tribasic lead sulfate to lead and the cycle life cycle ratio of a battery.

FIG. 3 is a diagram showing a relationship between an average length of prismatic PbO ₂ and an initial capacity ratio of a battery.

FIG. 4 is a diagram showing a relationship between a specific surface area of an active material layer and an initial capacity ratio of a battery.

FIG. 5 is a diagram showing the relationship between the amount of power applied to a battery used in the test and the discharge time.

FIG. 6 is a diagram showing the cycle life characteristics of the batteries used in the test.

FIG. 7 is a diagram showing the relationship between the thickness of a conventional anode plate for a lead storage battery and the discharge time.

──────────────────────────────────────────────────続 き Continuation of front page (72) Inventor Ichiro Mukaya 2-1-1, Nishi-Shinjuku, Shinjuku-ku, Tokyo Inside Shin-Kobe Electric Co., Ltd. (56) References JP-A-4-79156 (JP, A) JP-A-4-79156 Hei 5-242887 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01M 4/14-4/62

Claims (2)

(57) [Claims] 1. A current collector filled with an active material paste and dried
After forming the dried electrode plate and drying the undried electrode plate,
The method for producing an anode plate for a lead-acid battery according to claim 1, wherein the active material paste is obtained by kneading tribasic lead sulfate, lead red and water.
To form the inner active material paste layer by filling
And the active material paste obtained by kneading leadtan and water is mixed with the inner active material.
Fill on top of paste layer to form outer active material paste layer
Method for producing a positive electrode plate for a lead storage battery, characterized in that to produce the on Therefore the wet electrode plate step of. 2. A lead storage device in which an active material is held on a current collector.
In the anode plate for a pond, the active material is a prismatic diacid having a dimension of each part of 1 μm or less.
Crystal structure of spherical or flat lead dioxide bonded to lead iodide
Having an inner active material layer having a thickness of 1 μm or less
From the outer active material layer having a columnar lead dioxide crystal structure
An anode plate for a lead storage battery, comprising: