JP2018018743A - Lead storage battery - Google Patents

Abstract

An object of the present invention is to provide a lead-acid battery that is intended to improve low-temperature, high-rate discharge performance. A positive electrode plate, a negative electrode plate, and an electrolyte solution are provided. The negative electrode plate includes a negative electrode material, and the negative electrode material contains an organic anti-shrink agent. The content of elemental sulfur (S element) in the organic shrinking agent is more than 3000 μmol / g and not more than 9000 μmol / g. The specific gravity of the electrolytic solution is 1.28 or more. [Selection] Figure 2

Description

  The present invention relates to a lead-acid battery.

  A technique for adding an organic shrinking agent (expander) to a negative electrode material of a lead storage battery is disclosed (see Patent Document 1). It is disclosed that good low-temperature high-rate discharge performance can be obtained by adding an organic shrinking agent.

International Publication No. WO2015 / 181865

However, the low-temperature high-rate discharge performance is not always sufficient, and further improvement has been demanded.
This invention is made | formed in view of the said conventional situation, Comprising: It aims at further improving low-temperature high-rate discharge performance.

The present inventors have developed a novel lead-acid battery as a result of intensive studies in view of the above-described conventional technology.
And this new lead acid battery discovered the fact that low-temperature high-rate discharge performance is favorable. The present invention has been made based on this finding.

That is, the lead acid battery according to one aspect of the present invention is
A positive electrode plate;
A negative electrode plate;
A lead storage battery comprising an electrolyte solution,
The negative electrode plate includes a negative electrode material,
The negative electrode material contains an organic shrinking agent,
The content of elemental sulfur (S element) in the organic shrinking agent is more than 3000 μmol / g and 9000 μmol / g or less,
The specific gravity of the electrolytic solution is 1.28 or more.

  According to the lead acid battery according to one aspect of the present invention, the pores of the negative electrode are not covered with lead sulfate and the pores are not easily blocked by the combination of the specific organic shrinkage agent and the specific electrolyte. . As a result, very good low temperature and high rate discharge performance can be obtained.

It is a graph which shows the relationship between electrolyte solution specific gravity and S element content in an organic shrinkage agent, and 0.2CA discharge duration (h). It is a graph which shows the relationship between electrolyte solution specific gravity and S element content in an organic shrinkage agent, and low temperature high-rate discharge duration (s). It is a graph which shows the relationship between S element content and electrolyte solution specific gravity in an organic preshrink agent, and low temperature high-rate discharge duration (s). It is a graph which shows the relationship between the density of negative electrode material, and low temperature high-rate discharge duration (s).

  A preferred embodiment of the present invention will be described.

1. Lead acid battery The lead acid battery of 1 aspect of this invention is equipped with a positive electrode plate, a negative electrode plate, and electrolyte solution. The negative electrode plate includes a negative electrode material, and the negative electrode material contains an organic anti-shrink agent. The content of elemental sulfur (S element) in the organic shrinking agent is more than 3000 μmol / g and not more than 9000 μmol / g. The specific gravity of the electrolytic solution is 1.28 or more.
The electrode material includes not only the reactants but also all other additives. The electrode plate is made of an electrode material and a current collector. Therefore, the electrode material means all the rest except the current collector from the electrode plate.

2. Positive electrode plate The type of the positive electrode plate is not particularly limited. As the positive electrode plate, for example, a clad electrode plate or a paste electrode plate can be used. As the clad plate, for example, a plate in which glass fibers are knitted into a tube shape and filled with a positive electrode material containing lead powder as a positive electrode active material is used. The paste type electrode plate is obtained, for example, by filling a current collector (grid body) such as expand, casting, punching, etc. with a paste of a positive electrode material containing a positive electrode active material, followed by aging and drying. The paste of the positive electrode material can be obtained by kneading lead powder or the like with water and dilute sulfuric acid. In addition to the positive electrode active material, various additives may be added to the paste of the positive electrode material.

3. 3. Negative electrode plate 3.1 Type of electrode plate The type of the negative electrode plate is not particularly limited. For example, a paste-type electrode plate can be used as the negative electrode plate. As the paste type electrode plate, for example, a current collector (grid) produced by casting using pure lead or a lead alloy, or an expanded or punched sheet obtained by processing a sheet using pure lead or a lead alloy An electrode plate in which a paste-formed negative electrode material is applied to a current collector (lattice body) is used. The paste type electrode plate is obtained, for example, by filling a current collector with a paste of a negative electrode material and then aging and drying. The paste of the negative electrode material can be obtained by kneading lead powder or the like with water and dilute sulfuric acid. In addition to the negative electrode active material, various additives may be added to the negative electrode material paste. As an additive for the negative electrode material, carbon materials such as carbon black, activated carbon, various graphites, and barium sulfate may be used.

3.2 Density of negative electrode material In the lead storage battery of one embodiment of the present embodiment, the density of the negative electrode material is not particularly limited. The density of the negative electrode material is preferably not more than 2.5 g / cm ³ or more 4.0 g / cm ^3, further preferably not more than 2.7 g / cm ³ or more 3.8 g / cm ^3, particularly preferably It is 2.7 g / cm ³ or more and 3.5 g / cm ³ or less. When the density of the negative electrode material is within this range, particularly good low-temperature high-rate discharge performance tends to be obtained.
The density of the negative electrode material means the value of the bulk density of the fully charged negative electrode material after formation, and is measured as follows. The battery after chemical conversion is fully charged and disassembled, and the obtained negative electrode plate is washed with water and dried to remove the electrolyte in the negative electrode plate. Next, the negative electrode material is separated from the negative electrode plate to obtain an unground measurement sample. After putting the sample into the measurement container and evacuating it, filling the mercury with a pressure of 0.5 to 0.55 psia, measuring the bulk volume of the negative electrode material, and dividing the mass of the measurement sample by the bulk volume, the negative electrode Find the bulk density of the material. The volume obtained by subtracting the mercury injection volume from the volume of the measurement container is defined as the bulk volume.

3.3 Organic Shrinkage Agent 3.3.1 Content of Organic Shrinkage Agent In the lead storage battery of the present embodiment, the negative electrode material contains an organic shrunk agent. The content of the organic anti-shrink agent is not particularly limited. The content of the organic shrunk agent is preferably 0.05 mass% or more and 0.3 mass% or less with respect to 100 mass% of the negative electrode material in a fully charged state. When the organic shrinking agent is within this range, the low-temperature high-rate discharge performance tends to be improved.

3.3.2 Details of Organic Shrinkage Agent The type of organic shrinkage agent in the present embodiment is not particularly limited. One organic shrinking agent may be used alone, or two or more organic shrinking agents may be used in combination.
Organic shrinking agents are classified into natural shrinking agents and synthetic shrinking agents.
Examples of the natural product-derived shrinkage-preventing agent include sulfonated lignin. When a sulfonic acid group is introduced into the alkyl side chain of lignin, it is difficult to introduce one or more sulfonic acid groups into the alkyl side chain. Therefore, indirectly introduced lignin can be used without directly introducing a sulfonic acid group or a sulfonyl group into the alkyl side chain of lignin. That is, a sulfonic acid group and / or a sulfonyl group can be introduced directly into the phenyl group of lignin or indirectly through an alkyl group. Thus, when a sulfonic acid group and / or a sulfonyl group are introduced into lignin, the content of sulfur element (S element) can be increased.

Further, examples of the synthetic anti-shrinking agent include a reaction product of a compound having a plurality of phenolic hydroxyl groups and an aldehyde, a reaction product of a naphthalene compound and an aldehyde. In addition, polyacrylic acid, polymer of acrylamide / tertiary butyl / sulfonic acid Na (ATBS polymer: ATBS is a registered trademark), N, N ′-(sulfonyldi-4,1-phenylene) bis (1,2,3 , 4-tetrahydro-6methyl-2,4-dioxopyrimidine-5-sulfonamide) can also be used.
In the polymer of polyacrylamide, tertiary butyl, and sodium sulfonate, the ratio of the basic skeleton to the amount of sulfonic acid groups is not particularly limited, but the ratio of the basic skeleton to the amount of sulfonic acid groups is 1: 1 or more. Is preferred.

The compound having a plurality of phenolic hydroxyl groups is not particularly limited as long as it has a phenolic hydroxyl group, and may have a plurality. These compounds may be used alone or in combination of two or more.
Bisphenols are preferably used as the compound having a plurality of phenolic hydroxyl groups. Bisphenols are compounds having two hydroxyphenyl groups. Examples of bisphenols include bisphenol A, bisphenol S, bisphenol F, bisphenol AP, bisphenol AF, bisphenol B, bisphenol BP, bisphenol C, bisphenol E, bisphenol G, bisphenol M, bisphenol P, bisphenol PH, bisphenol TMC, and bisphenol Z. Etc. are exemplified. These may be used alone or in combination of two or more.

  Aldehydes are not particularly limited. Examples of aldehydes include formaldehyde, paraformaldehyde, trioxane, tetraoxymethylene and the like. These may be used alone or in combination of two or more. Formaldehyde is preferably used because of its high reactivity with a compound having a plurality of phenolic hydroxyl groups.

Further, a sulfonic acid group (sulfo group) may be further introduced into the reaction product of a compound having a plurality of phenolic hydroxyl groups and aldehydes. By introducing a sulfonic acid group, the amount of elemental sulfur (S element) in the synthetic anti-shrinkage agent can be increased.
The sulfonic acid group does not need to be directly bonded to the aromatic ring (for example, the phenyl group of bisphenol) of a compound having a plurality of phenolic hydroxyl groups. For example, an alkyl chain may be bonded to the aromatic ring, and a sulfonic acid group may be bonded to the alkyl chain.
Even if the S element is contained as a sulfonic acid group or a sulfonyl group, the performance as a shrink-preventing agent is almost the same.

In the lead storage battery of the present embodiment, the content of elemental sulfur (S element) in the organic shrinkage agent is more than 3000 μmol / g and not more than 9000 μmol / g, preferably not less than 4000 μmol / g and not more than 9000 μmol / g, more Preferably they are 5000 micromol / g or more and 8000 micromol / g or less, More preferably, they are 6000 micromol / g or more and 8000 micromol / g or less.
When the content of sulfur element (S element) is within this range, particularly good low-temperature high-rate discharge performance tends to be obtained.

The molecular weight of the organic shrinking agent is not particularly limited. The weight average molecular weight (Mw) of the organic shrinking agent is preferably from 1,000 to 1,000,000, more preferably from 1,000 to 100,000, and still more preferably from 1,000 to 20,000. This range is preferred from the viewpoint of organic synthesis.
The molecular weight is determined by gel permeation chromatography (GPC). The standard substance used for determining the molecular weight is sodium polystyrene sulfonate.
The molecular weight can be measured using the following apparatus and conditions.
GPC equipment: Build-up GPC system
SD-8022 / DP-8020 / AS-8020 / CO-8020 / UV-8020 (Tosoh)
Column: TSKgel G4000SWXL, G2000SWXL (7.8 mmI.D. × 30cm) (Tosoh)
Detector: UV detector λ = 210nm
Eluent: 1mol / L NaCl: Acetonitrile (7: 3)
Flow rate: 1ml / min.
Concentration: 10 mg / mL
Injection volume: 10μL
Standard substance: Polystyrene sulfonate Na
(Mw = 275,000, 35,000, 12,500, 7,500, 5,200, 1,680)

Specific examples of the compound having a plurality of phenolic hydroxyl groups include condensates of bisphenol A introduced with sulfonic acid groups by formaldehyde, condensates of bisphenol S introduced with sulfonic acid groups by formaldehyde, and formaldehyde of β-naphthalene sulfonic acid. The condensate obtained by (trade name “Demol”, Kao Corporation) can be preferably used. In the case where bisphenol S is used, a sulfonic acid group and an S element derived from a sulfonyl group (—SO ₂ —) structure in bisphenol S are present in the synthetic shrink-proofing agent.

  Furthermore, a condensate of bisphenols is preferable. The condensate of bisphenols is suitable for a lead storage battery in a temperature environment higher than room temperature because performance at low temperature is not impaired even if it experiences a temperature environment higher than room temperature. The condensate of naphthalene sulfonic acid is less likely to have a smaller polarization than the condensate of bisphenols, and is therefore suitable for a lead storage battery in which liquid reduction characteristics are important.

Here, an example of a suitable synthesis method of the condensate of bisphenols is shown. Bisphenols (bisphenol A, S, F, etc.), formaldehyde, and sulfite are mixed to obtain a formaldehyde condensate of bisphenols. At this time, the amount of S of the shrink reducing agent is adjusted by increasing or decreasing the amount of bisphenol S and the amount of sulfite according to the required amount.
However, it is preferable to contain sulfite and formaldehyde in an approximately equimolar amount for reaction. In addition, since superposition | polymerization advances in alkaline conditions, it is preferable to use NaOH etc. as a pH adjuster and to be set to about pH = 12 (pH = 10-13).

  The reaction temperature is not particularly limited, and is preferably 140 ° C. or higher and 200 ° C. or lower. During the reaction, it may or may not be stirred.

  In addition, the temperature / time conditions can be adjusted so that a weight average molecular weight with respect to temperature / reaction time is obtained in advance and a condensate having a desired weight average molecular weight is obtained. Particularly preferably, the reaction is performed by adjusting the temperature and time conditions so that the weight average molecular weight (Mw) is about 9000 (6000 to 13000).

The stable form of the element S in the organic shrinking agent is a sulfonyl group or a sulfonic acid group, and is often contained as a sulfonyl group or a sulfonic acid group. The amount of S element contained in the sulfonic acid group and the sulfonyl group is mainly the S element content of the organic shrinking agent.
That is, when a sulfonic acid group (sulfo group) is further introduced using bisphenol S, the total amount of the S element of the sulfonic acid group and the S element of the sulfonyl group is the main amount.
As described above, the S element in the organic shrinking agent is contained as a sulfonyl group or a sulfonic acid group. These groups are hydrophilic groups having a strong polarity. Due to electrostatic repulsion between these groups, these groups tend to appear on the surface of the organic anti-shrink agent particles in the electrolytic solution. As a result, the association of the colloidal organic shrinking agent is limited, and the size of the colloidal particles of the organic shrinking agent, in other words, the colloidal particle diameter of the organic shrinking agent is reduced.

In order to reduce the average colloidal particle size in sulfuric acid for the organic shrinking agent, for example, the amount of hydrophilic functional groups (sulfonyl group, sulfonic acid group, hydroxyl group, etc.) per gram of organic shrinking agent having a plurality of phenolic hydroxyl groups It is effective to increase
In order to measure the average colloidal particle diameter of the organic shrinking agent, an aqueous solution of the organic shrinking agent having a concentration of 1 to 10 mg / mL is diluted 20 times by volume with sulfuric acid having a specific gravity of 1.26. A solution of 25 sulfuric acid is used. A sample diluted 20-fold with sulfuric acid is measured, for example, using a laser diffraction / scattering particle size distribution measuring apparatus LA-950V2 manufactured by HORIBA, Ltd. at 25 ° C. using a batch type cell and stirring with a magnetic stirrer. Then, the volume-based average colloid particle diameter is obtained. Coexisting ions such as lead ion, aluminum ion and sodium ion hardly affect the measured value of the average colloid particle diameter.
The aqueous solution of the organic shrinking agent is, for example, extracted from the negative electrode plate of the lead storage battery, washed with water to remove sulfuric acid, and then dissolved in an alkali such as a 1.0 M NaOH aqueous solution to extract the organic shrinking agent. Can be obtained.

  The S element content of the organic anti-shrinking agent can be adjusted by the use ratio of compounds such as bisphenol S and naphthalenesulfonic acid, the conditions for sulfonation, and the like.

3.3.3 Identification of type of organic shrinkage agent The identification of the organic shrinkage agent in the negative electrode material is performed as follows. The fully charged lead acid battery is disassembled, the negative electrode plate is taken out, washed with water to remove sulfuric acid, and dried. A negative electrode material containing an active material is separated from the negative electrode plate, and the organic electrode shrinkant is extracted by immersing the negative electrode material in a 1 mol / L NaOH aqueous solution. A solution obtained by removing insoluble components by filtration from the extract is desalted and then concentrated and dried to obtain a powder sample. For desalting, a desalting column or an ion exchange membrane is used.
Infrared spectroscopic spectrum measured using a powder sample of the organic shrunk agent obtained in this way, or a powder sample dissolved in distilled water or the like, and measured with an ultraviolet-visible spectrophotometer, an ultraviolet-visible absorption spectrum, or a predetermined solvent such as heavy water The information obtained from the NMR spectrum of the obtained solution after being dissolved is used in combination to identify the type of organic anti-shrink agent.
In addition, the auxiliary charge conditions to make a full charge state are as follows.
(1) In the case of a liquid battery, constant current charging is performed at 25 ° C. in a water tank until it reaches 2.5 V / cell at 0.2 CA, and then constant current charging is further performed at 0.2 CA for 2 hours.
(2) In the case of a VRLA battery (control valve type lead acid battery), constant current and constant voltage charge of 0.2 CA, 2.23 V / cell is performed in an air tank at 25 ° C., and the charge current during constant voltage charge is 1 mCA or less When it becomes, charging ends.

In this specification, 1CA is a current value for discharging the nominal capacity of the battery in one hour. For example, if the battery has a nominal capacity of 30 Ah, 1CA is 30 A, and 1 mCA is 30 mA.

3.3.4 Measurement of content of organic shrinkage agent The content of the organic shrinkage agent in the negative electrode material is measured as follows.
The fully charged lead acid battery is disassembled, the negative electrode plate is taken out, washed with water to remove sulfuric acid, and dried. The negative electrode material is separated from the negative electrode plate, and 100 g of the negative electrode material is immersed in 300 mL of 1 mol / L NaOH aqueous solution to extract the organic anti-shrink agent. After removing insoluble components from the extract by filtration, an ultraviolet-visible absorption spectrum is measured, and the content of the organic shrinking agent in the negative electrode material is measured using a calibration curve prepared in advance.
When obtaining a battery made by another company and measuring the content of the organic shrunk agent, if the same organic shrunk agent cannot be used in the calibration curve because the structural formula of the organic shrunk agent cannot be strictly specified, By creating a calibration curve using an organic shrunk agent that is available separately, the organic shrunk agent extracted from the negative electrode of the battery and the UV-visible absorption spectrum, infrared spectroscopic spectrum, and NMR spectrum show similar shapes. Then, the content of the organic anti-shrink agent is measured using an ultraviolet-visible absorption spectrum.

3.3.5 Measurement of S Element Content in Organic Shrink Agent The S element content (hereinafter also simply referred to as “S element content”) of the organic shrunk agent in the negative electrode material is measured as follows.
The fully charged lead acid battery is disassembled, the negative electrode plate is taken out, washed with water to remove sulfuric acid, and dried. The negative electrode material is separated from the negative electrode plate, and the organic electrode shrinking agent is extracted by immersing the negative electrode material in a 1 mol / L NaOH aqueous solution. A solution obtained by removing insoluble components by filtration from the extract is desalted and then concentrated and dried to obtain a powder sample. For desalting, a desalting column or an ion exchange membrane is used.
Oxygen combustion flask method converts elemental sulfur in 0.1 g of organic shrinkage agent to sulfuric acid. At this time, an eluate in which sulfate ions are dissolved in the adsorbent is obtained by burning the powder sample in the flask containing the adsorbent.
Then, the eluate is titrated with barium perchlorate using trin as an indicator to determine the S element content in 0.1 g of the powder sample. This S element content is converted into a quantity per 1 g to obtain the S element content in the organic shrinking agent.

3.4 Other Components The negative electrode plate may contain other components other than the above-described components. For example, carbon black, graphite, synthetic resin fiber, BaSO ₄ or the like may be included.

4). Electrolytic Solution The electrolytic solution is preferably a sulfuric acid aqueous solution containing sulfuric acid and water. The specific gravity of the electrolytic solution is 1.28 or more, more preferably 1.30 or more, and still more preferably 1.31 or more. The upper limit of the specific gravity of the electrolytic solution is usually 1.32. When the specific gravity of the electrolyte is within this range, particularly good low-temperature high-rate discharge performance can be obtained. The specific gravity of the electrolytic solution is a converted value of 20 ° C.
The electrolyte solution may contain other components such as alkali metal ions, alkaline earth metal ions, aluminum ions, silica, phosphoric acid, and boric acid.

The chemical conversion can be performed by charging the electrode plate group in a state in which the electrode plate group including the unformed negative electrode plate is immersed in an electrolytic solution containing sulfuric acid in the battery case of the lead storage battery. However, the chemical conversion treatment may be performed before the assembly of the lead storage battery or the electrode plate group. Sponge-like lead is generated by chemical conversion.
In addition, the auxiliary charge conditions to make a full charge state are as follows.

  Hereinafter, the present invention will be described more specifically with reference to examples.

1. And manufacturing lead powder of lead-acid battery, an organic expander agent, and carbon black, and BaSO _4, were kneaded with water and sulfuric acid, and the negative electrode material paste. The paste of the negative electrode material was filled in a cast lattice made of a Pb—Sb alloy, and aged and dried to obtain an unformed negative electrode plate.
Sulfonated lignin (lignin sulfonic acid) was used as an organic anti-shrink agent having an S element content of 600 μmol / g.
A formaldehyde condensate of bisphenols was used as an organic shrinking agent having an S element content of 3000 to 9000 μmol / g. Specifically, the formaldehyde condensate of bisphenols was synthesized as follows.
The content of S element in the organic shrinking agent was adjusted by appropriately changing the ratio of bisphenol A, F, S and the degree of sulfonation.
The content of the organic shrinkage agent and barium sulfate in the already formed negative electrode material is 0.1 mass% for the organic shrinkage agent and 1.5% for the barium sulfate with respect to 100 mass% of the fully formed negative electrode material. Thus, a negative electrode plate was prepared by adjusting.
Further, the density of the negative electrode material was measured by using the above-described method using a Shimadzu Corp., automatic porosimeter, Autopore IV95505, which was disassembled after the formed battery was fully charged. (The input values of the contact angle and surface tension of the automatic porosimeter are not related to the bulk volume and do not affect the measured value. If the input of the contact angle and surface tension is necessary for the convenience of the equipment, it is optional. Enter a value and perform the operation.)
In the ratio of the amount of the organic shrinking agent in the negative electrode material, the value obtained by separating and quantifying the negative electrode taken out from the manufactured battery by the above method is somewhat different from the ratio mixed at the time of electrode preparation. Become. In the examples of the present invention, each of the batteries having an elemental content of sulfur (S element) (μmol / g) of 600, 3000, 4000, 6000, and 8000 in the organic shrinking agent has the following ratio R: Asked.
A = mass ratio (mass%) of the organic shrinkage agent to the negative electrode material determined by separating and quantifying the negative electrode taken out from the manufactured battery by the above-described method.
B = mass ratio (mass%) of the organic shrinkage agent mixed at the time of battery production to the negative electrode material
R = A / B
The content (mass%) of the organic shrinkage agent in the negative electrode material described in Tables 1 to 4 is the mass ratio (mass%) of the mixed organic shrinkage agent to the negative electrode material at the time of battery production in each battery. This is obtained by multiplying the above-described R obtained for batteries having the same content of sulfur element (S element) in the organic shrinking agent.
About the amount of S element (μmol / g) in the organic shrinking agent,
It was confirmed that there was no difference between the value before mixing as the negative electrode material and the value measured after being disassembled from the battery and extracted.
(Therefore, for the amount of elemental S (μmol / g) in the organic shrinkage agents listed in Tables 1 to 4, the values obtained by measurement in each of the organic shrinkage agents before mixing as the negative electrode material are described. ing.)

Lead powder, red lead, and Sb ₂ O ₃ were kneaded with water and sulfuric acid to obtain a paste for a positive electrode material. A clad in which a brazing lattice made of a Pb—Sb alloy is prepared from this paste, and a glass fiber is knitted into a tube shape around each lattice, filled with a positive electrode active material, and sealed with a resin part The electrode plate was dried and aged to obtain an unformed positive electrode plate.
Using the negative electrode plate and the positive electrode plate thus manufactured, a lead storage battery having a nominal capacity of 165 Ah for 5 hours was manufactured.

2. 2.1 Performance evaluation test 2.1 Low-temperature high-rate discharge performance The low-temperature high-rate discharge performance is evaluated from the initial value of the number of seconds until the terminal voltage decreases to 1.0 V under the condition of a discharge current of 150 A at −15 ° C. did.

2.2 Low-rate discharge performance Evaluation was made based on the time from the fully charged state until the terminal voltage decreased to 1.7 V with a discharge current of 0.2 CA.

3. Result The result of each performance evaluation is shown to Tables 1-4, and the graph obtained from Tables 1-4 is shown to FIGS. In the figure, “S element 600” indicates a case where sulfonated lignin (lignin sulfonic acid) having an S element content of 600 μmol / g is used.
“S element 5000” indicates a case where a formaldehyde condensate of bisphenols having an S element content of 5000 μmol / g is used.

3.1 Relationship between Electrolyte Specific Gravity and S Element Content in Organic Shrink Agent and 0.2 CA Discharge Duration (h) Low rate discharge performance was evaluated by changing the electrolyte specific gravity. The density of the negative electrode material was 3.8 g / cm ³ .

From Table 1 and FIG. 1, when the organic shrunk agent with S element content of 5000 μmol / g is contained in the negative electrode material and the specific gravity of the electrolyte is 1.28 or more, the low rate discharge performance is high. Was confirmed.
Further, as shown in FIG. 1, the graph of the S element content of 5000 μmol / g has a larger slope than the graph of the S element content of 600 μmol / g. Therefore, when the S element content of 5000 μmol / g is used, it is extremely important to focus on the specific gravity of the electrolyte in order to improve the low-rate discharge performance compared to the case where the S element content of 600 μmol / g is used. It turns out to be effective.
Further, as shown in FIG. 1, an inflection point was observed in the vicinity of 1.25 in the specific gravity of the electrolytic solution in the graph of the S element content of 5000 μmol / g. This is a characteristic not shown in the graph of the S element content of 600 μmol / g.
Since there is an inflection point in the graph of the S element content of 5000 μmol / g, when the specific gravity of the electrolyte is 1.25 or more when the S element content is 5000 μmol / g, the S element content From the data when the specific gravity of the electrolyte is 1.25 or more at 600 μmol / g, it can be seen that the prediction is impossible. This is a foreign effect that cannot be predicted.

3.2 Relationship between Electrolyte Specific Gravity and S Element Content in Organic Shrink Agent and Low Temperature High Rate Discharge Duration (s) The low temperature high rate discharge performance was evaluated by changing the electrolyte specific gravity. The density of the negative electrode material was 3.8 g / cm ³ .

From Table 2 and FIG. 2, when the organic shrunk agent having an S element content of 5000 μmol / g is contained in the negative electrode material and the specific gravity of the electrolyte is 1.28 or more, the low-temperature high-rate discharge performance is high. Was confirmed.
Also, from Table 2 and FIG. 2, when the S element content is 5000 μmol / g and the specific gravity of the electrolyte is 1.28 or more, the low temperature high rate discharge duration time when the S element content is 600 μmol / g. It was found that the low temperature high rate discharge duration was longer than the maximum value (electrolyte specific gravity 1.28, 153 s).
In addition, in the case of S element content of 5000 μmol / g, in the case of S element content of 600 μmol / g, both tend to decrease when the maximum value of the low temperature high rate discharge duration is exceeded, but the former is more than the latter The trend was a gradual decrease.

  The reason which became the result of Tables 1-2 and FIGS. 1-2 is estimated as follows. That is, it is presumed that the higher the S element concentration, the smaller the colloidal particle diameter of the organic shrinking agent, and the smaller the pore diameter of the negative electrode active material. Furthermore, when the S element concentration is high, the specific resistance of the negative electrode material is estimated to be small. When the S element concentration is high and the specific gravity of the electrolytic solution is increased, the low temperature high rate discharge performance and the low rate discharge capacity are considered to be improved by the synergistic effect of both.

3.3 Relationship between S Element Content and Electrolyte Specific Gravity in Organic Shrink Agent and Low Temperature High Rate Discharge Duration (s) The low temperature high rate discharge performance was evaluated by changing the S element content and electrolyte specific gravity. The density of the negative electrode material was 3.1 g / cm ³ .

From Table 3 and FIG. 3, when the S element content exceeds 3000 μmol / g and contains an organic shrinkage agent of 9000 μmol / g or less in the negative electrode material, and the specific gravity of the electrolyte is 1.28 or more, It was confirmed that the high rate discharge performance was high.
Further, as shown in FIG. 3, it was found that the graph in which the specific gravity of the electrolytic solution is 1.28 or more has a clearly larger slope than the graph in which the specific gravity is 1.25. Therefore, when using an electrolytic solution with a specific gravity of 1.28 or more, it is possible to focus on the S element content in order to improve the low-temperature high-rate discharge performance as compared with the case of using an electrolytic solution with a specific gravity of 1.25. It was confirmed that it was extremely effective.
In addition, as shown in FIG. 3, an inflection point was observed in the vicinity of the S element content of 3000 μmol / g to 4000 μmol / g in the graph in which the specific gravity of the electrolytic solution was 1.28 or more. This is a characteristic that the specific gravity of the electrolytic solution is not in the graph of 1.25.
Since there is an inflection point in the graph where the specific gravity of the electrolytic solution is 1.28 or more, the low temperature high-rate discharge performance in a battery in which the S element content exceeds 3000 μmol / g when using an electrolytic solution having a specific gravity of 1.28 or more. Is not predictable from the low-temperature high-rate discharge performance in a battery in which the S element content exceeds 3000 μmol / g when the specific gravity of the electrolyte is 1.25. This is a foreign effect that cannot be predicted.

Here, the results of Table 3 and FIG. 3 are considered.
In a lead storage battery, when aiming at the increase in discharge capacity, it is possible to make electrolyte specific gravity high. Although this leads to an increase in discharge capacity, there is a trade-off that the low-temperature high-rate discharge performance deteriorates. This contradiction is presumed to occur because the pores of the negative electrode plate are likely to be clogged in an environment using a high specific gravity electrolyte, and the capacity of the negative electrode plate is likely to be limited.
If an organic shrunk agent having an S element content of 4000 μmol / g or more and 9000 μmol / g or less is used for the negative electrode plate as in this example, the specific gravity is higher than that when an organic shrunk agent having an S element content of 600 μmol / g is used. It was confirmed that a decrease in low-temperature high-rate discharge performance at 1.28 or higher is suppressed. Particularly, the low-temperature high-rate discharge performance at a specific gravity of 1.30 or more was good.

Pore clogging is caused by precipitation of lead sulfate, and when it occurs, the movement of ions is limited, and it is estimated that the high-rate performance particularly at low temperatures is lowered.
When an organic anti-shrinkage agent having an S element content of more than 3000 μmol / g and not more than 9000 μmol / g is added to the negative electrode plate, a small pore is formed, so that the surface area of the negative electrode plate and the pore per unit mass can be increased. It is done.
When the pore is reduced, the concentration gradient during the discharge reaction inside the pore is increased, and the ion diffusion rate in the electrolytic solution is increased. By this effect, it is estimated that the specific resistance is reduced and the active material can be used uniformly. That is, it is considered that the active material surface can be used uniformly. In addition, where the organic anti-shrink agent is present, it is not covered with lead sulfate, and pore clogging is unlikely to occur. Therefore, it is considered that the low-temperature high-rate discharge performance can be improved even in a situation where a high specific gravity electrolyte is used under low-temperature conditions.

3.4 Relationship between Negative Electrode Material Density and Low Temperature High Rate Discharge Duration (s) Low Temperature High Rate Discharge by Changing Density of Negative Electrode Material (Described as “Negative Electrode Density” in Tables and Figures) and Electrolyte Specific Gravity Performance was evaluated.

From Table 4 and FIG. 4, the negative electrode material contains an organic shrunk agent having a negative electrode electrode density of 2.5 g / cm ³ or more and 4.0 g / cm ³ or less and an S element content of 5000 μmol / g, In addition, it was confirmed that the low temperature high rate discharge performance was high when the specific gravity of the electrolytic solution was 1.28 or more.
Specifically, when the specific gravity of the electrolytic solution is 1.28, the use of an organic shrunk agent having an S element content of 5000 μmol / g is lower than the case of an organic shrunk agent having an S element content of 600 μmol / g. Was found to be extremely high. Furthermore, even when the specific gravity of the electrolytic solution is 1.30, which is larger than 1.28, it is better to use an organic shrinking agent having an S element content of 5000 μmol / g and an organic shrinking agent having an S element content of 600 μmol / g. It was confirmed that the low-temperature high-rate discharge performance was extremely higher than that of the agent.

  Even when a naphthalene-based shrinkage agent such as a condensate of β-naphthalenesulfonic acid with formaldehyde is used as the organic shrinkage agent, (1) the content of S element in the organic shrinkage agent is 3000 μmol / g. When the specific gravity of the electrolyte is 1.28 or more, the same effect as that obtained when a bisphenol-based anti-shrink agent is used can be obtained.

  The present invention is not limited to the embodiments described above with reference to the drawings.

  The present invention can be widely applied to lead-acid batteries.

Claims (3)

A positive electrode plate;
A negative electrode plate;
A lead storage battery comprising an electrolyte solution,
The negative electrode plate includes a negative electrode material,
The negative electrode material contains an organic shrinking agent,
The content of elemental sulfur (S element) in the organic shrinking agent is more than 3000 μmol / g and 9000 μmol / g or less,
The lead acid battery having a specific gravity of 1.28 or more.   The lead acid battery according to claim 1, wherein the organic shrinking agent is a synthetic shrinking agent. The lead acid battery according to claim 1 or 2, wherein a density of the negative electrode material is 2.5 g / cm ³ or more and 4.0 g / cm ³ or less.