JP2022009931A - Lead acid battery - Google Patents

Abstract

SOLUTION: A lead acid battery includes a negative electrode plate, a positive electrode plate, and an electrolytic solution, and the negative electrode plate includes a negative electrode grid and a negative electrode material, and the negative electrode material includes an organic shrinkage proofing agent including a sulfur element. The content of the sulfur element in the organic shrinkage proofing agent is 6000 μmol/g or more, and the height of the negative electrode plate exceeds 10 cm.

SELECTED DRAWING: Figure 1

COPYRIGHT: (C)2022,JPO&INPIT

Description

The present invention relates to a lead storage battery.

Lead-acid batteries are used in various applications such as in-vehicle use and industrial use. The lead-acid battery includes a negative electrode plate, a positive electrode plate, and an electrolytic solution. A separator is arranged between the negative electrode plate and the positive electrode plate. In lead-acid batteries used for industrial applications such as forklifts, a negative electrode plate and a positive electrode plate having a large height are housed in a large electric tank. For example, Patent Document 1 describes a lead storage battery including an electric tank having a height of 190 to 700 mm. Patent Document 2 describes a lead storage battery including a negative electrode plate having a height of 120 cm and a positive electrode plate.

Japanese Unexamined Patent Publication No. 2013-41757 Japanese Unexamined Patent Publication No. 59-186262

However, since the charging efficiency of the lower portion of the electrode plate is low in the negative electrode plate having a large height, lead sulfate is accumulated in the lower portion in the lead storage battery.

One aspect of the present invention includes a negative electrode plate, a positive electrode plate, and an electrolytic solution.
The negative electrode plate comprises a negative electrode current collector and a negative electrode material.
The negative electrode material contains an organic shrinkage proofing agent containing a sulfur element, and the negative electrode material contains.
The content of the sulfur element in the organic shrinkage proofing agent is 4000 μmol / g or more, and the content is 4000 μmol / g or more.
The height of the negative electrode plate relates to a lead storage battery having a height of more than 10 cm.

According to the present invention, even in a lead storage battery using a negative electrode plate having a large height, the accumulation of lead sulfate in the lower part of the negative electrode plate can be suppressed.

It is a perspective view which shows typically the state which the lid of the lead storage battery which concerns on one aspect of this invention is removed. It is a front view of the lead storage battery of FIG. FIG. 2 is a cross-sectional view taken along the line IIB-IIB of the lead storage battery of FIG. 2A. It is a graph which shows the relationship between the height (6 to 30 cm) of a negative electrode plate and the accumulation amount of lead sulfate when the organic shrinkage agent containing different sulfur elements is used. It is a graph which shows the relationship between the height (6 to 50 cm) of a negative electrode plate and the accumulation amount of lead sulfate when the organic shrinkage agent containing different sulfur elements is used. It is a graph which shows the relationship between the height (6 to 30 cm) of a negative electrode plate and the life cycle of a lead storage battery when the organic shrinkage agent containing different sulfur elements is used. It is a graph which shows the relationship between the height (6 to 50 cm) of a negative electrode plate and the life cycle of a lead storage battery when the organic shrinkage agent containing different sulfur elements is used. It is a graph which shows the relationship between the content of the sulfur element of the organic shrinkage proofing agent, and the 5-hour rate capacity when the negative electrode having different densities of the negative electrode electrode material is used.

Although the novel features of the invention are described in the appended claims, the invention is further described in detail with respect to both configuration and content, in conjunction with other objects and features of the invention, with reference to the drawings below. It will be well understood.

The lead storage battery according to one aspect of the present invention includes a negative electrode plate, a positive electrode plate, and an electrolytic solution, the negative electrode plate includes a negative electrode current collector and a negative electrode electrode material, and the negative electrode electrode material is sulfur. The content of the sulfur element in the organic shrink-proofing agent containing the organic shrinkage-proofing agent is 4000 μmol / g or more, and the height of the negative electrode plate exceeds 10 cm.

The negative electrode material of a lead storage battery generally contains an active material (spoiled lead or lead sulfate) whose capacity is developed by a redox reaction. In the negative electrode plate, the reduction reaction of lead sulfate proceeds during charging, but lead sulfate is difficult to be reduced to spongy lead. Therefore, it is known that sulfation in which lead sulfate crystals gradually grow progresses. In a lead-acid battery, an ear portion for electrically connecting to an external terminal of the lead-acid battery is formed at an upper end portion of a negative electrode plate and a positive electrode plate. In the lower region of the negative electrode plate, the distance to the selvage portion is longer than in the upper region, so that the resistance is increased accordingly. When a large negative electrode plate having a height of more than 10 cm is used, the resistance becomes particularly large in the lower region of the negative electrode plate, and the charge / discharge reaction proceeds preferentially in the upper region. Further, by repeating the charge / discharge reaction, the sulfuric acid concentration of the electrolytic solution under the battery becomes high, so that the charging efficiency is lowered. As a result, sulfation tends to proceed in the lower part of the negative electrode plate.

Further, in general, in a lead storage battery using a negative electrode plate having a large height (for example, an industrial lead storage battery), an organic shrink proofing agent such as lignin or lignosulfonic acid (hereinafter referred to as lignin) derived from a natural product is used. Has been done. The content of the sulfur element contained in lignin is usually 500 μmol / g or more and 600 μmol / g or less.

On the other hand, in the above aspect of the present invention, by using the negative electrode electrode material containing the organic shrink-proofing agent having a sulfur element content of 4000 μmol / g or more, the negative electrode plate having a height of more than 10 cm is used. Accumulation of lead sulfate in the lower region of the negative electrode plate can be suppressed. Further, by suppressing the accumulation of lead sulfate during charging and discharging, the life of the lead storage battery can be extended.

Therefore, in the lead storage battery according to the above aspect of the present invention, in particular, the negative electrode plate is provided so that the ear portion is provided at the upper end portion of the negative electrode plate and the ear portion is located above the lead storage battery with the lead storage battery installed. Suitable for placement. In this case, the distance from the lower part of the negative electrode plate to the selvage portion becomes long, and the resistance tends to increase. However, even in such a case, according to the present embodiment, the accumulation of lead sulfate in the region of the lower part of the negative electrode plate is effective. Can be suppressed.

The lead storage battery may be either a control valve type (sealed type) lead storage battery or a liquid type (vent type) lead storage battery. In particular, in a liquid lead-acid battery, the ear portion of the negative electrode plate is arranged so as to be located above the lead-acid battery, but even in such a case, according to the present embodiment, the region below the negative electrode plate The accumulation of lead sulfate in the above can be effectively suppressed.

The height of the negative electrode plate is the height of the region where the negative electrode material is present in the negative electrode plate (specifically, the length from the lower end to the upper end of the portion where the negative electrode current collector is filled with the negative electrode material). To say. The height of the positive electrode plate also refers to the height of the region where the positive electrode material is present in the positive electrode plate, as in the case of the negative electrode plate.

The upper and lower sides of the negative electrode plate and the positive electrode plate are such that the side where the selvage is present is the upper side of each electrode plate, and the side opposite to the selvage portion is the lower side of each electrode plate. Therefore, the end portion on the side where the selvage portion exists is the upper end portion of each electrode plate. On the other hand, the upper and lower parts of the lead-acid battery mean the upper and lower parts when the lead-acid battery is installed, regardless of the position of the selvage portion on each electrode plate.

In the present specification, the lower region of the negative electrode plate is a region of 30% or less of the height of the negative electrode plate from below the negative electrode plate (specifically, the lower end where the negative electrode material is present). Further, when examining the accumulated amount of lead sulfate in the region below the negative electrode plate, the examination shall be carried out at a position 20% from the bottom of the negative electrode plate.

The lead-acid battery according to the above aspect of the present invention can be used as a lead-acid battery for automobiles, but is particularly suitable for an industrial lead-acid battery because it uses a negative electrode plate having a large height. Examples of the industrial lead-acid battery include an emergency power supply, an emergency power backup, a power supply for an electric vehicle (forklift, etc.) and the like. A forklift is a material handling vehicle equipped with a fork that supports luggage and a mast that raises and lowers the fork. As a cargo handling vehicle such as a forklift, an electric vehicle driven by a battery has been widely used, and it is suitable to use the lead storage battery according to the above aspect of the present invention.

The lead-acid battery for an electric vehicle is a liquid-type lead-acid battery, and the height of the negative electrode plate is often high. In such a case, the distance from the lower region of the negative electrode plate to the selvage portion located at the upper end of the negative electrode plate becomes long, and the amount of lead sulfate accumulated tends to increase. According to the above aspect of the present invention, the accumulation of lead sulfate in the lower part of the negative electrode plate can be effectively suppressed even in such a case.

The organic shrinkage proofing agent used in the lead storage battery according to the above aspect of the present invention contains 4000 μmol / g or more of sulfur elements. From the viewpoint of further enhancing the effect of suppressing the accumulation of lead sulfate in the lower region of the negative electrode plate, the content of the sulfur element in the organic shrinkage proofing agent is preferably 6000 μmol / g or more. In this case, even if a negative electrode plate having a height of 15 cm or more or 20 cm or more is used, the accumulation of lead sulfate in the lower region can be effectively suppressed. Further, when the content of the sulfur element in the organic shrinkage inhibitor is 7,000 μmol / g or more, the accumulation of lead sulfate can be significantly suppressed, and this suppressing effect can be obtained even when the height of the negative electrode plate is 20 cm or more. The content of the sulfur element in the organic shrinkage proofing agent is preferably 10,000 μmol / g or less, and more preferably 9000 μmol / g or less, in terms of preventing softening and falling off of the positive electrode and suppressing a decrease in the 5-hour rate capacity.

The content of the sulfur element in the organic shrinkage proofing agent is Xμmol / g means that the content of the sulfur element contained in 1 g of the organic shrinkage proofing agent is Xμmol / g.

The density of the negative electrode material can be appropriately adjusted in the range of, for example, 2.5 g / cm ³ or more and 5 g / cm ³ or less. From the viewpoint of weight reduction of the lead storage battery, 2.5 g / cm ³ or more and 4.5 g / cm ³ or less is preferable, and 2.5 g / cm ³ or more and 4.2 g / cm ³ or less is more preferable. When an organic shrink-proofing agent having a high sulfur element content is used, the negative electrode active material is made finer and sulfuric acid is less likely to penetrate into the negative electrode plate, so that the 5-hour rate capacity tends to decrease. From the viewpoint of suppressing the decrease in the 5-hour rate capacity, the density of the negative electrode electrode material is preferably, for example, 2.5 g / cm ³ or more and 4.0 g / cm ³ or less. In particular, when an organic shrink-proofing agent having a sulfur element content of 6000 μmol / g or more is used, the density of the negative electrode electrode material is set to 4.0 g / cm ³ or less to effectively reduce the 5-hour rate capacity. It can be suppressed.

In general, when the density of the negative electrode material is reduced and the void density is increased, it is usually expected that the resistance increases and the 5-hour rate capacity decreases. However, contrary to this expectation, in the above aspect of the present invention, even if the density of the negative electrode material is reduced (for example, 4.0 g / cm ³ or less), lead sulfate accumulation in the lower region of the negative electrode plate is accumulated. While suppressing it, the 5-hour rate capacity can be improved.

The negative electrode current collector of a lead storage battery is generally formed by a processing method such as a casting method, an expanding method, or a punching method. Above all, the lattice body formed by the punching method can have a smaller resistance than the current collector formed by the other method. By combining such a current collector and an organic shrink-proofing agent having a sulfur element content of 4000 μmol / g or more, the resistance of the entire negative electrode plate can be effectively suppressed to a low level, so that the height of the negative electrode plate is increased. However, the accumulation of lead sulfate in the lower region of the negative electrode plate can be effectively suppressed. Further, when a lattice body is used as the negative electrode current collector, it is easy to support the negative electrode electrode material and it is easy to adjust the resistance of the negative electrode current collector.

In general, in the use of industrial lead-acid batteries, the lead-acid batteries are often used after being fully charged. The present inventor has noticed that when the lead-acid battery is used in such a charged state, the effect due to the difference in the sulfur element content of the organic shrinkage proofing agent is likely to become apparent due to the difference in the height of the negative electrode plate. In the lead-acid battery according to the above aspect of the present invention, the ratio (= charge amount / discharge amount) of the charge electricity amount (also referred to as charge amount) to the discharge electricity amount (also referred to as discharge amount) is 100% or more. When charging / discharging is performed, the effect of suppressing the accumulation of lead sulfate in the lower part of the negative electrode plate can be further enhanced by using an organic shrinkage barrier having a sulfur element content of 4000 μmol / g or more. Therefore, a high life cycle can be ensured even in a negative electrode plate having a height of more than 10 cm.

The charge / discharge ratio when charging / discharging the lead storage battery is, for example, 100% or more, preferably 115% or more, and may be 120% or more or 125% or more. The charge / discharge ratio is, for example, 200% or less, preferably 150% or less, and may be 130% or less or 125% or less. These lower limit values and upper limit values can be arbitrarily combined. In the charge / discharge cycle test of JIS5303-1, it is stipulated that the test for an electric vehicle (electric vehicle) is performed when the ratio of charge amount / discharge amount is 115% or more and 125% or less. According to the above aspect of the present invention, even when the charge / discharge ratio is in the range of 115% or more and 125% or less, the lower part of the negative electrode plate is used by using an organic shrinkage proofing agent having a sulfur element content of 4000 μmol / g or more. It is possible to obtain a high effect of suppressing the accumulation of lead sulfate in. On the other hand, even when charging / discharging is performed with a charge / discharge ratio of 100% or more (for example, 115% or more, 120% or more, or 125% or more), an organic shrinkage proofing agent having a sulfur element content of less than 4000 μmol / g. With a negative electrode plate having a height of more than 10 cm, it becomes difficult to secure a high life cycle.

The charging electricity amount is an integrated value (Ah) of the current at the time of charging, and the discharging electricity amount is an integrated value (Ah) of the current at the time of discharging. For example, when charging (or discharging) with a constant current, the charging electricity amount (or discharging electricity amount) is obtained by multiplying the current value (A) at that time by the charging time (or discharging time) (h). Can be asked.

Hereinafter, the lead-acid battery according to the embodiment of the present invention will be described for each of the main constituent requirements, but the present invention is not limited to the following embodiments.
(Negative electrode plate)
The negative electrode plate of a lead storage battery is composed of a negative electrode current collector and a negative electrode material. The negative electrode electrode material is obtained by removing the negative electrode current collector from the negative electrode plate. The negative electrode current collector may be formed by casting lead (Pb) or a lead alloy, or may be formed by processing a lead or lead alloy sheet. Examples of the processing method include expanding processing and punching processing. Above all, the resistance of the lattice body formed by the punching method tends to be small. By combining such a lattice and an organic shrink-proofing agent having a sulfur content of 4000 μmol / g or more, the resistance of the entire negative electrode plate can be suppressed to a low level, so that even if the height of the negative electrode plate is made larger than 10 cm ( (Preferably, even if it is 15 cm or more or 20 cm or more), the accumulation of lead sulfate can be suppressed more effectively. Further, the lattice body is preferable because it is easy to support the negative electrode electrode material and it is easy to adjust the resistance of the negative electrode current collector.

The lead alloy used for the current collector may be any of a Pb—Sb alloy, a Pb—Ca alloy, and a Pb—Ca—Sn alloy. These leads or lead alloys may further contain, as an additive element, at least one selected from the group consisting of Ba, Ag, Al, Bi, As, Se, Cu and the like. The negative electrode current collector may have lead alloy layers having different compositions, and may have a plurality of alloy layers.

The negative electrode electrode material contains a negative electrode active material (lead or lead sulfate) whose capacity is developed by a redox reaction and an organic shrinkage proofing agent containing 4000 μmol / g or more of a sulfur element in a predetermined content. The negative electrode material may further contain a carbonaceous material such as carbon black, barium sulfate and the like, and may contain other additives as needed.

The negative electrode active material in the charged state is spongy lead, but the unchemical negative electrode plate is usually produced using lead powder.

The organic shrinkage proofing agent is an organic polymer containing a sulfur element, and generally contains a plurality of aromatic rings in the molecule and also contains a sulfur element as a sulfur-containing group. Among the sulfur-containing groups, a sulfonic acid group or a sulfonyl group, which is a stable form, is preferable. The sulfonic acid group may be present in acid form or may be present in salt form such as Na salt.

As a specific example of the organic shrinkage proofing agent, a condensate of a compound having a sulfur-containing group and an aromatic ring with formaldehyde is preferable. The compound may have a plurality of aromatic rings. Examples of the aromatic ring include a benzene ring and a naphthalene ring. When the compound having an aromatic ring has a plurality of aromatic rings, the plurality of aromatic rings may be directly bonded or linked by a linking group (for example, an alkylene group, a sulfone group, etc.). Examples of such a structure include biphenyl, bisphenyl alkane, bisphenyl sulfone and the like. Examples of the compound having an aromatic ring include the above-mentioned aromatic ring and a compound having a hydroxy group and / or an amino group. The hydroxy group or amino group may be directly bonded to the aromatic ring, or may be bonded as an alkyl chain having a hydroxy group or amino group. As the compound having an aromatic ring, a bisphenol compound, a hydroxybiphenyl compound, a hydroxynaphthalene compound, a phenol compound and the like are preferable. The compound having an aromatic ring may further have a substituent. The organic shrinkage proofing agent may contain one kind of residues of these compounds, or may contain a plurality of kinds. As the bisphenol compound, bisphenol A, bisphenol S, bisphenol F and the like are preferable. Among them, since bisphenol S has a sulfonyl group (-SO _2- ), it is easy to increase the content of sulfur element. The condensate of the bisphenol compound is suitable for lead-acid batteries placed in a temperature environment higher than normal temperature because the starting performance at low temperature is not impaired even if the environment is higher than normal temperature.

The sulfur-containing group may be directly bonded to the aromatic ring contained in the compound, or may be bonded to the aromatic ring as an alkyl chain having a sulfur-containing group, for example. Further, for example, a monocyclic aromatic compound such as aminobenzenesulfonic acid or alkylaminobenzenesulfonic acid may be condensed with formaldehyde together with the above-mentioned compound having an aromatic ring.

Condensates of N, N'-(sulfonyldi-4,1-phenylene) bis (1,2,3,4-tetrahydro-6-methyl-2,4-dioxopyrimidine-5-sulfonamide) are organic It may be used as a shrink-proofing agent.

The content of the organic shrink-proofing agent contained in the negative electrode electrode material does not greatly affect the action of the organic shrinkage-proofing agent as long as it is in the general range. The content of the organic shrinkage-proofing agent contained in the negative electrode electrode material is, for example, preferably 0.01% by mass or more, more preferably 0.02% by mass or more, further preferably 0.05% by mass or more, while 1.0. It is preferably 0% by mass or less, more preferably 0.8% by mass or less, still more preferably 0.3% by mass or less. Here, the content of the organic shrinkage-proofing agent contained in the negative electrode electrode material is the content in the negative electrode material collected by the method described later from a prefabricated lead-acid battery in a fully charged state.

The height of the negative electrode plate may be higher than 10 cm, and may be 15 cm or more or 20 cm or more. The height of the negative electrode plate is, for example, 150 cm or less, preferably 100 cm or less, and may be 80 cm or less. These lower limit values and upper limit values can be arbitrarily combined. When the height of the negative electrode plate is in such a range, the effect of using an organic shrinkage proofing agent having a sulfur element content of 4000 μmol / g or more can be easily obtained. Therefore, since the resistance of the negative electrode material can be suppressed to a low level, the accumulation of lead sulfate in the lower region of the negative electrode plate can be suppressed even if the height of the negative electrode plate is high as described above.

The negative electrode plate can be formed by filling a negative electrode current collector with a negative electrode paste, aging and drying to produce an unchemical negative electrode plate, and then forming an unchemical negative electrode plate. The negative electrode paste is prepared by adding water and sulfuric acid to lead powder, an organic shrink-proofing agent and, if necessary, various additives, and kneading them. In the aging step, it is preferable to ripen the unchemical negative electrode plate at a temperature higher than room temperature and high humidity.

The chemical conversion can be carried out by charging the electrode plate group in a state where the electrode plate group including the unchemical negative electrode plate is immersed in the electrolytic solution containing sulfuric acid in the electric tank of the lead storage battery. However, the chemical formation may be performed before assembling the lead-acid battery or the electrode plate group. The formation produces spongy lead.

(Positive plate)
There are two types of positive electrode plates for lead-acid batteries: paste type and clad type.
The paste type positive electrode plate includes a positive electrode current collector and a positive electrode material. The positive electrode material is held in the positive current collector. In the paste type positive electrode plate, the positive electrode electrode material is the positive electrode plate minus the positive electrode current collector. The positive electrode current collector may be formed in the same manner as the negative electrode current collector, and can be formed by casting lead or a lead alloy or processing a lead or a lead alloy sheet.

The clad type positive electrode plate has a plurality of porous tubes, a core metal inserted in each tube, a positive electrode material filled in the tube into which the core metal is inserted, and a collective punishment for connecting multiple tubes. Equipped with. In the clad type positive electrode plate, the positive electrode material is the positive electrode plate excluding the tube, the core metal, and the collective punishment.

As the lead alloy used for the positive electrode current collector, Pb-Ca-based alloys and Pb-Ca-Sn-based alloys are preferable in terms of corrosion resistance and mechanical strength. The positive electrode current collector may have lead alloy layers having different compositions, and may have a plurality of alloy layers. It is preferable to use a Pb—Ca alloy or a Pb—Sb alloy for the core metal.
The positive electrode material contains a positive electrode active material (lead dioxide or lead sulfate) that develops a capacity by a redox reaction. The positive electrode material may contain other additives, if necessary.

The unchemical paste type positive electrode plate can be obtained by filling a positive electrode current collector with a positive electrode paste, aging and drying, as in the case of a negative electrode plate. After that, an unchemical positive electrode plate is formed. The positive electrode paste is prepared by kneading lead powder, additives, water and sulfuric acid.

The clad type positive electrode plate is formed by filling a tube into which a core metal is inserted with lead powder or slurry-like lead powder, and connecting a plurality of tubes in a collective punishment. The obtained unchemical positive electrode plate is formed.

(Separator)
As the separator, a non-woven fabric, a microporous membrane, or the like is used. The thickness and number of separators interposed between the negative electrode plate and the positive electrode plate may be appropriately selected according to the distance between the electrodes. The non-woven fabric is a mat that is entwined without weaving fibers, and is mainly composed of fibers (for example, 60% by mass or more is formed of fibers). As the fiber, glass fiber, polymer fiber (polyolefin fiber such as polyolefin fiber, acrylic fiber, polyethylene terephthalate fiber, etc.), pulp fiber and the like can be used. Of these, glass fiber is preferable. The non-woven fabric may contain components other than fibers, such as an acid-resistant inorganic powder, a polymer as a binder, and the like.

On the other hand, the microporous film is a porous sheet mainly composed of components other than fiber components. For example, a composition containing a pore-forming agent (polymer powder and / or oil, etc.) is extruded into a sheet and then pore-formed. It is obtained by removing the agent to form pores. The material constituting the separator is preferably an acid resistant material, and the polymer component is preferably a polyolefin such as polyethylene or polypropylene.

The separator may be composed of, for example, only a non-woven fabric or only a microporous membrane. Further, the separator may be, if necessary, a laminate of a non-woven fabric and a microporous membrane, a material obtained by laminating different or similar materials, or a material in which different or similar materials are engaged with male and female.

(Electrolytic solution)
The electrolytic solution is an aqueous solution containing sulfuric acid, and may be gelled if necessary. The specific gravity of the electrolytic solution in a fully charged lead-acid battery after chemical conversion at 20 ° C. is, for example, 1.10 g / cm ³ or more and 1.35 g / cm ³ or less, and 1.20 g / cm ³ or more and 1.35 g / cm ³ The following is preferable.

Next, an analysis method for each physical property will be described.
(1) Density of Negative Electrode Material The density of the negative electrode material means the value of the bulk density of the negative electrode material in a fully charged state after chemical conversion, and is measured as follows. The battery after chemical conversion is fully charged and then disassembled, and the obtained negative electrode plate is washed with water and vacuum dried (dried under a pressure lower than atmospheric pressure) to remove the electrolytic solution in the negative electrode plate. Next, the negative electrode material is separated from the negative electrode plate to obtain an unground measurement sample. After the sample is put into the measuring container and evacuated, the bulk volume of the negative electrode material is measured by filling mercury with a pressure of 0.5 psia or more and 0.55 psia or less (≈3.45 kPa or more and 3.79 kPa or less). The bulk density of the negative electrode material is obtained by dividing the mass of the measurement sample by the bulk volume. The volume obtained by subtracting the mercury injection volume from the volume of the measuring container is defined as the bulk volume.

In the present specification, the fully charged state of a lead-acid battery means that in the case of a liquid battery, it reaches 2.5 V / cell at a 5-hour rate current (that is, a current of 0.2 CA) in a water tank at 25 ° C. After the constant current charge, the constant current charge is further performed for 2 hours at a rate current of 5 hours. In the case of a control valve type battery, the fully charged state means that the battery is charged at a constant current and constant voltage of 2.23 V / cell at a rate of 5 hours in an air tank at 25 ° C. Charging is completed when the current becomes 1 mCA or less.
In the present specification, 1CA is a current value (A) having the same numerical value as the nominal capacity (Ah) of the battery. For example, in the case of a battery having a nominal capacity of 30 Ah, 1CA is 30 A and 1 mCA is 30 mA.

(2) Analysis of organic shrinkant Next, the negative electrode material (initial sample) is collected from the dried negative electrode plate, and the initial sample is analyzed by the following method.

(2-1) Qualitative analysis of the organic shrinkage proofing agent in the negative electrode material The initial sample is immersed in a 1 mol / L sodium hydroxide (NaOH) aqueous solution to extract the organic shrinkage proofing agent. Next, the insoluble component is removed by filtration from the extracted NaOH aqueous solution containing an organic shrinkage proofing agent, the obtained filtrate is desalted by dialysis, concentrated, and dried. Desalination is performed by passing the filtrate through an ion exchange membrane, or by placing the filtrate in a dialysis tube and immersing it in distilled water. This gives a powder sample of the organic shrink proofing agent.

Predetermined infrared spectroscopic spectra measured using the powder sample of the organic shrink proofing agent thus obtained, ultraviolet-visible absorption spectra measured by an ultraviolet-visible absorptiometer after diluting the powder sample with distilled water, etc., and heavy water, etc. The organic shrink-proofing agent species is specified by dissolving in a solvent and using a combination of information obtained from the NMR spectrum of the obtained solution and the like.

(2-2) Quantification of the content of the organic shrinkage proofing agent in the negative electrode material In the same manner as in (2-1) above, after obtaining a filtrate of the NaOH aqueous solution containing the organic shrinkage proofing agent, the ultraviolet-visible absorption spectrum of the filtrate is measured. do. The content of the organic shrinkage barrier in the negative electrode electrode material is quantified using the spectral intensity and the calibration curve prepared in advance.

When a lead-acid battery having an unknown content of the organic shrinkage proof is obtained and the content of the organic shrinkage proofing agent is measured, the structural formula of the organic shrinkage proofing agent cannot be specified exactly, so that the same organic shrinkage proofing is applied to the calibration curve. The agent may not be available. In this case, calibration is performed using an organic shrinkage proofing agent extracted from the negative electrode of the battery and a separately available organic shrinkage proofing agent having a similar shape in the ultraviolet-visible absorption spectrum, the infrared spectroscopic spectrum, and the NMR spectrum. By creating a line, the content of the organic shrink-proofing agent shall be measured using the ultraviolet-visible absorption spectrum.

(2-3) Content of sulfur element in organic shrinkage proofing agent In the same manner as in (2-1) above, after obtaining a powder sample of the organic shrinkage proofing agent, 0.1 g of the organic shrinkage proofing agent is added by the oxygen combustion flask method. Converts the sulfur element of the to sulfuric acid. At this time, by burning the powder sample in the flask containing the adsorbent, an eluate in which sulfate ions are dissolved in the adsorbent is obtained. Next, by titrating the eluate with barium perchlorate using thorin as an indicator, the content (C1) of the sulfur element in 0.1 g of the organic shrink-proofing agent is determined. Next, C1 is multiplied by 10 to calculate the content of sulfur element (μmol / g) in the organic shrinkage proofing agent per 1 g.

FIG. 1 is a perspective view schematically showing an example in which the lid of the lead storage battery according to the embodiment of the present invention is removed. 2A is a front view of the lead-acid battery of FIG. 1, and FIG. 2B is a cross-sectional view taken along the line IIB-IIB of FIG. 2A.
The lead-acid battery 1 includes an electric tank 10 that houses the electrode plate group 11 and the electrolytic solution 12. The electrode plate group 11 is configured by laminating a plurality of negative electrode plates 2 and positive electrode plates 3 via a separator 4, respectively. Here, the negative electrode plate 2 is wrapped in the bag-shaped separator 4, but the form of the separator is not particularly limited.

At the upper part of each of the plurality of negative electrode plates 2, an ear portion (not shown) for collecting electricity is provided so as to project upward. An ear portion (not shown) for collecting electricity is also provided on the upper portion of each of the plurality of positive electrode plates 3 so as to project upward. The ears of the negative electrode plate 2 are connected to each other by the negative electrode strap 5a and integrated. Similarly, the ears of the positive electrode plate 3 are also connected and integrated by the positive electrode strap 5b. The lower end of the negative electrode column 6a is fixed to the upper part of the negative electrode strap 5a, and the lower end of the positive electrode column 6b is fixed to the upper part of the positive electrode strap 5b.

The lead-acid batteries according to one aspect of the present invention are summarized below.
(1) A lead storage battery, wherein the lead storage battery includes a negative electrode plate, a positive electrode plate, and an electrolytic solution.
The negative electrode plate comprises a negative electrode current collector and a negative electrode material.
The negative electrode material contains an organic shrinkage proofing agent containing a sulfur element, and the negative electrode material contains.
The content of the sulfur element in the organic shrinkage proofing agent is 4000 μmol / g or more, and the content is 4000 μmol / g or more.
The height of the negative electrode plate is a lead storage battery exceeding 10 cm.

(2) In the above (1), the content of the sulfur element is preferably 6000 μmol / g or more.

(3) In the above (1) or (2), the height of the negative electrode plate is preferably 20 cm or more.

(4) In any one of the above (1) to (3), the density of the negative electrode material is preferably 2.5 g / cm ³ or more and 4.0 g / cm ³ or less.

(5) In any one of the above (1) to (4), the negative electrode plate has an ear portion at the upper end portion of the negative electrode plate, and the ear portion is in a state where the lead storage battery is installed. , It is preferable that it is located above the lead storage battery.

(6) In any one of the above (1) to (5), the height of the negative electrode plate is preferably 100 cm or less.

(7) In any one of the above (1) to (6), it is preferable that the negative electrode current collector is a punched lattice body.

(8) In any one of the above (1) to (7), the content of the sulfur element is preferably 10,000 μmol / g or less or 9000 μmol / g or less.

(9) In any one of the above (1) to (8), the content of the organic shrinkage-proofing agent contained in the negative electrode electrode material is preferably 0.01% by mass or more.

(10) In any one of the above (1) to (9), the content of the organic shrinkage-proofing agent contained in the negative electrode electrode material is preferably 1.0% by mass or less.

(11) In any one of the above (1) to (10), it is preferable that the lead-acid battery is charged / discharged at a charge / discharge ratio of 100% or more.

(12) In any one of the above (1) to (11), the lead storage battery is preferably for an electric vehicle.

Hereinafter, the present invention will be specifically described based on Examples and Comparative Examples, but the present invention is not limited to the following Examples.

<< Reference example 1 >>
(1) Preparation of Negative Electrode Plate (a) Preparation of Negative Electrode Plate with Height 20 cm Lead powder, water, dilute sulfuric acid, barium sulfate, carbon black, and a predetermined amount of organic shrink-proofing agent are mixed to obtain a negative electrode paste. The negative electrode paste is filled in the mesh portion of the expanded lattice made of Pb—Ca—Sn alloy, and aged and dried to obtain an unchemicald negative electrode plate (height 20 cm). As the organic shrinkage proofing agent, a condensate of a bisphenol compound having a sulfonic acid group introduced by formaldehyde is used. Here, the amount of the sulfonic acid group to be introduced is controlled so that the content of the sulfur element in the organic shrinkage proofing agent is 4000 μmol / g.

Regarding the sulfur element content (μmol / g) in the organic shrinkage proofing agent, there is a difference between the value before preparing the negative electrode electrode material and the value measured by disassembling the lead storage battery and extracting the organic shrinkage proofing agent. do not have. Therefore, as the sulfur element content in the organic shrinkage proofing agents described in Examples, Reference Examples, and Comparative Examples, the values obtained for the organic shrinkage proofing agent before preparing the negative electrode electrode material are described below.

The amount of the organic shrinkage proofing agent is adjusted so that the content (A (mass%)) of the organic shrinkage proofing agent contained in 100% by mass of the negative electrode electrode material after being fully charged is 0.15% by mass. And mix it with the negative electrode paste. When preparing the negative electrode paste, the amount of water and dilute sulfuric acid added to the negative electrode paste is adjusted so that the density of the negative electrode material after being fully charged is 4.0 g / cm ³ . The density of the negative electrode material is determined by using the measured sample collected by disassembling the battery after the chemical conversion after fully charging the battery in the procedure described above. The battery is fully charged according to the procedure described above. The density of the negative electrode material is measured by the method described above using an automatic porosimeter (Autopore IV9505) manufactured by Shimadzu Corporation.

(B) Preparation of negative electrode plates having different heights According to the case of the negative electrode plate having a height of 20 cm in (a) above, the heights are 6 cm, 10 cm, 15 cm, 30 cm, 40 cm, 50 cm and 60 cm. Each of the negative electrode plates is manufactured.

(2) Preparation of positive electrode plate Lead powder, water, and sulfuric acid are kneaded to prepare a positive electrode paste. The positive electrode paste is filled in the mesh portion of the expanded lattice made of Pb—Ca—Sn based alloy, and aged and dried to obtain an unchemicald positive electrode plate. The height of the unchemical positive electrode plate shall be the same as the height of the unchemical negative electrode plate.

(3) Preparation of lead-acid battery The unchemical negative electrode plate is housed in a bag-shaped separator formed of a polyethylene microporous membrane, and 5 unchemical negative electrode plates and 4 unchemical positive electrode plates are used per cell. Form a group of plates. The unchemical negative electrode plate and the unchemical positive electrode plate are combined at the same height.

The electrode plate group is inserted into a polypropylene electric tank, an electrolytic solution is injected, and chemical formation is performed in the electric tank. For each electrode plate group using a negative electrode plate and a positive electrode plate of each height, a liquid type Assemble the lead-acid battery. The terminal voltage of the lead storage battery is 2V, and the nominal capacity is 8Ah / cm per 1 cm of the height of the electrode plate.

The content (A (mass%)) of the organic shrinkage-proofing agent contained in the negative electrode material (100% by mass) taken out from the negative electrode plate is determined for one of the manufactured lead-acid batteries by the procedure described above. The content of the organic shrinkage proofing agent quantified in this way was somewhat different from the content of the organic shrinkage proofing agent (B (mass%)) in the negative electrode electrode material (100% by mass) prepared for the lead storage battery. It becomes a value. Therefore, when the ratio R (= A / B) of these contents A and B is obtained in advance and the negative electrode material to be used for the negative electrode plate of another lead storage battery is prepared, the ratio R is used to obtain the negative electrode. The content of the organic shrinkage-proofing agent (B (mass%)) in the prepared negative electrode electrode material is adjusted so that the content of the organic shrinkage-proofing agent (A (mass%)) in the material becomes a predetermined value. Further, in Examples, Reference Examples, and Comparative Examples, the ratio R was obtained for each sulfur element content of the organic shrinkage proofing agent used, and the obtained ratio was obtained for the negative electrode material using the organic shrinkage proofing agent having the same sulfur element content. The content of the organic shrinkage proofing agent (B (% by mass)) is adjusted based on R.

<< Examples 1 to 4 and Reference Example 2 >>
The content of the sulfur element in the organic shrinkage proofing agent is 6000 μmol / g (Example 1), 7000 μmol / g (Example 2), 8000 μmol / g (Example 3), 9000 μmol / g (Example 4), or 3000 μmol. The amount of the sulfonic acid group introduced into the formaldehyde-based condensate of the bisphenol compound is adjusted so as to be / g (Reference Example 2). A negative electrode plate having each height is formed in the same manner as in Reference Example 1 except that each of these organic shrink proofing agents having a sulfur element content is used. A lead storage battery is assembled in the same manner as in Reference Example 1 except that the obtained negative electrode plate is used.

<< Comparative Example 1 >>
Similar to Reference Example 1, a negative electrode plate having each height is formed, except that lignin derived from a natural product and having a sulfur element content of 600 μmol / g is used instead of the synthetic organic shrinkage proofing agent. A lead storage battery is assembled in the same manner as in Reference Example 1 except that the obtained negative electrode plate is used.

[Evaluation 1]
The lead-acid batteries produced in Examples 1 to 4, Reference Examples 1 and 2, and Comparative Example 1 were subjected to a charge / discharge cycle test, and at the 600th cycle, the lower part of the negative electrode plate (20% from the bottom of the height of the negative electrode plate). Investigate the amount of lead sulfate accumulated at (position). The charge / discharge cycle test is performed in accordance with JIS5303-1. More specifically, the cycle of discharging the lead-acid battery at a temperature of 40 ° C. at a current value of 0.25 CA for 3 hours and charging the lead storage battery at a current value of 0.2 CA to 125% of the discharge amount is repeated.

In the measurement of the accumulated amount of lead sulfate, first, the negative electrode plate is taken out from the lead storage battery, the negative electrode plate is washed with water, and vacuum dried (dried under a pressure lower than atmospheric pressure). Negative electrode material is collected from the lower part of the negative electrode plate and crushed. Next, the content of sulfur element in the crushed negative electrode material (crushed sample) is measured using a sulfur element analyzer (for example, S-200 type manufactured by LECO). Then, the content of the sulfur element in the lead sulfate accumulated in the negative electrode electrode material is determined according to the following formula.

Sulfur element content in lead sulfate = (content of sulfur element obtained by sulfur element analyzer)-(mass of crushed sample (g) x content of organic shrinkage proofing agent (g / g) x in organic shrinkage proofing agent Sulfur element content (g / g))

Next, the content of the sulfur element in lead sulfate is converted into the amount of lead sulfate, and the lead sulfate concentration (% by mass) per unit mass of the pulverized sample is obtained and used as the accumulated amount of lead sulfate. The amount of lead sulfate accumulated is expressed as a ratio (%) when the accumulated amount of lead sulfate is 100 when the height of the negative electrode plate is 6 cm in Comparative Example 1. It can be said that the greater the amount of lead sulfate accumulated, the more the sulfation and the stratification of the electrolytic solution progress.

Tables 1 and 3 and Tables 2 and 4 show the relationship between the height of the negative electrode plate and the accumulated amount of lead sulfate for each organic shrinkage agent having a different sulfur element content. Tables 1 and 2 show the accumulated amount (%) of lead sulfate in the lower part of the negative electrode plate.

Comparative Example 1 and Reference Example 2 using an organic shrinkage proofing agent having a sulfur element content of 600 μmol / g to 3000 μmol / g, and Reference Example 1 and Examples 1 to 4 using an organic shrinkage proofing agent having a sulfur element content of 4000 μmol / g or more. Then, the behavior of the change in the accumulated amount of lead sulfate with respect to the height of the negative electrode plate is completely different (Table 1 and FIG. 3).

Specifically, in Comparative Example 1 and Reference Example 2, the accumulated amount of lead sulfate increases as the height of the negative electrode plate increases, and the accumulated amount of lead sulfate increases even at a height of more than 10 cm. .. On the other hand, in Reference Example 1 and Examples 1 to 4, when the height of the negative electrode is low, there is almost no change in the accumulated amount of lead sulfate, and even when the height exceeds 10 cm, the accumulated amount of lead sulfate does not change. It is looser than that of Comparative Example 1 and Reference Example 2. As described above, when the height exceeds 10 cm, the accumulated amount of lead sulfate is usually very large (Comparative Example 1 and Reference Example 2), but in Reference Example 1 and Examples 1 to 4, lead sulfate is accumulated. Accumulation can be greatly suppressed.

From Tables 1 and 3, and from Tables 2 and 4, the content of the sulfur element in the organic shrink-proofing agent is 6000 μmol / g or more from the viewpoint of obtaining a high effect of suppressing the accumulation of lead sulfate. preferable. In this case, even if the height of the negative electrode plate is 15 cm or more, the accumulation of lead sulfate can be suppressed. Further, when the content of the sulfur element in the organic shrink proofing agent is 7,000 μmol / g or more, even if the height of the negative electrode plate is 20 cm or more, the accumulation of lead sulfate in the lower region of the negative electrode plate is almost observed. I can't.

[Evaluation 2]
In the charge / discharge cycle test of evaluation 1, the number of cycles when the discharge capacity falls below 80% of the nominal capacity of the lead storage battery is determined, and the life cycle of the lead storage battery is evaluated. The life cycle of the lead storage battery is expressed as a ratio (%) when the life cycle when the height of the negative electrode plate is 6 cm in Comparative Example 1 is set to 100.

Tables 3 and 5, and Tables 4 and 6 show the relationship between the height of the negative electrode plate and the life cycle of the lead-acid battery when each organic shrinkage agent having a different sulfur element content is used. Tables 3 and 4 show the life cycle (%).

The results of the life cycle show similar results to the amount of lead sulfate accumulated in Tables 1 and 3, and Tables 2 and 4. That is, when the height of the negative electrode plate exceeds 10 cm, the life cycle is usually greatly reduced (Comparative Example 1 and Reference Example 2), but in Reference Example 1 and Examples 1 to 4, the life cycle is reduced. It is gradual. In particular, when the sulfur content of the organic shrinkage proofing agent is 6000 μmol / g or more or 7,000 μmol / g or more, even if the height of the negative electrode plate is as high as 15 cm or more or 20 cm or more, the decrease in the life cycle can be suppressed. can.

<< Example 5 >>
A negative electrode plate having a height of 20 cm is used in the same manner as in Reference Example 1 except that the amount of water and dilute sulfuric acid added to the negative electrode paste is adjusted so that the density of the ready-made negative electrode material becomes 2.5 g / cm ³ . To make.
Further, the content of the sulfur element in the organic shrinkage proofing agent is 5000 μmol / g (reference example), 6000 μmol / g, 7000 μmol / g, 8000 μmol / g, 9000 μmol / g, or 3000 μmol / g, respectively. Adjust the amount of sulfonic acid groups introduced into the formaldehyde condensate. A 20 cm negative electrode plate is formed in the same manner as in Reference Example 1 except that each of these organic shrink proofing agents having a sulfur element content is used.

A negative electrode plate having a height of 20 cm is formed in the same manner as in Example 1 except that lignin derived from a natural product and having a sulfur element content of 600 μmol / g is used instead of the synthetic organic shrinkage proofing agent.
Then, the lead storage battery is assembled in the same manner as in Reference Example 1 except that the negative electrode plate obtained above is used.

<< Example 6 >>
The content of each sulfur element is the same as in Example 5, except that the amount of water and dilute sulfuric acid added to the negative electrode paste is adjusted so that the density of the ready-made negative electrode material becomes 4.5 g / cm ³ . Therefore, a negative electrode plate having a height of 20 cm is produced.
Then, the lead storage battery is assembled in the same manner as in Reference Example 1 except that the negative electrode plate obtained above is used.

[Evaluation 3]
The 5-hour rate capacity of the lead-acid batteries produced in Examples 5 and 6 is determined as follows. The lead-acid battery is discharged at 0.20 CA from a fully charged state at an electrolytic solution temperature of 30 ° C. until the battery voltage reaches 1.72 V, and the discharge duration and discharge current at this time are obtained. The 5-hour rate capacity is obtained from the product of the discharge duration and the discharge current. Then, the 5-hour rate capacity is expressed as a ratio (%) when the 5-hour rate capacity is 100 when the negative electrode plate having a height of 20 cm of Comparative Example 1 is used.

Tables 5 and 7 show the relationship between the content of the sulfur element in the organic shrinkage proofing agent and the 5-hour rate capacity for the negative electrode plates having different densities of the negative electrode materials. In Table 5 and FIG. 7, when the height of the negative electrode plate is 20 cm in Reference Example 1, Examples 1 to 4, Reference Example 2 and Comparative Example 1 (density of negative electrode material = 4.0 g / cm ³ ). The results and the results of using an organic shrink-proofing agent corresponding to these cases and having a sulfur element content of 5000 μmol / g are also shown. Table 5 shows the 5-hour rate capacity (%).

As shown in Table 5 and FIG. 7, when the sulfur element content of the organic shrink proofing agent increases (specifically, it becomes 6000 μmol / g or more), the 5-hour rate capacity depends on the density of the negative electrode material. Decreases. Therefore, from the viewpoint of ensuring a high 5-hour rate capacity, the density of the negative electrode material is preferably 4.0 g / cm ³ or less.

<< Reference Example 1A >>
According to the case of the negative electrode plate having a height of 20 cm in Reference Example 1 (a), unchemical negative electrode plates having heights of 5 cm, 12 cm, 70 cm, and 80 cm are produced, respectively. A lead-acid battery is assembled in the same manner as in Reference Example 1 except that the obtained negative electrode plate is used.

<< Examples 1A to 4A and Reference Example 2A >>
The content of the sulfur element in the organic shrink proofing agent is 6000 μmol / g (Example 1A), 7000 μmol / g (Example 2A), 8000 μmol / g (Example 3A), 9000 μmol / g (Example 4A), or 3000 μmol. The amount of the sulfonic acid group introduced into the formaldehyde-based condensate of the bisphenol compound is adjusted so as to be / g (Reference Example 2A). A negative electrode plate having each height is formed in the same manner as in Reference Example 1A except that each of these organic shrink proofing agents having a sulfur element content is used. A lead-acid battery is assembled in the same manner as in Reference Example 1 except that the obtained negative electrode plate is used.

<< Comparative Example 1A >>
Similar to Reference Example 1A, a negative electrode plate having each height is formed except that lignin derived from a natural product and having a sulfur element content of 600 μmol / g is used instead of the synthetic organic shrinkage proofing agent. A lead storage battery is assembled in the same manner as in Reference Example 1 except that the obtained negative electrode plate is used.

[Evaluation 4]
The charge / discharge cycle test of Evaluation 1 is performed on the lead-acid batteries produced in Examples 1 to 4, Examples 1A to 4A, Reference Examples 1 to 2, Reference Examples 1A to 2A, Comparative Example 1 and Comparative Example 1A. More specifically, the cycle of discharging the lead-acid battery at a temperature of 40 ° C. at a current value of 0.25 CA for 3 hours and charging the lead storage battery at a current value of 0.2 CA to 125% of the discharge amount is repeated. That is, the ratio (= charge amount / discharge amount (%)) of the charge amount (that is, the charge electricity amount) at the time of charging to the discharge amount (that is, the discharge electricity amount) is 125%.
Further, the charge / discharge ratio is changed to 120% and 115%, respectively, and the cycle is repeated in the same manner as in the case of 125% above.
Then, the number of life cycles when the height of the negative electrode plate of Comparative Example 1 is 6 cm is set as the standard 100, and the minimum negative electrode whose life cycle number is less than 85% of the standard in the case of each charge amount / discharge amount ratio. Evaluate the height of the board. In the above Examples, Reference Examples, and Comparative Examples, the number of life cycles is remarkably reduced near 85% of the standard, so 85% of the standard is used as the threshold value for evaluation.
The results are shown in Table 6. Table 6 shows the minimum height (cm) of the negative electrode plate, which is less than 85% of the standard.

As shown in Table 6, when the charge / discharge ratio is 100% or more and the sulfur element content is less than 4000 μmol / g, the minimum height of the negative electrode plate, which is less than 85% of the standard, is It is 5 cm or 10 cm. On the other hand, when the sulfur element content is 4000 μmol / g or more, the minimum height of the negative electrode plate, which is less than 85% of the standard, exceeds 10 cm. Therefore, when the sulfur element content is 4000 μmol / g or more, it can be said that a high life cycle can be ensured even when the height of the negative electrode plate exceeds 10 cm. Further, as the charge / discharge ratio increases, the height of the minimum negative electrode plate, which is less than 85% of the standard, increases, and a long life cycle can be obtained. Such a difference between the example and the reference example and the comparative example is that the increase in resistance in the negative electrode electrode material becomes apparent in the reference example and the comparative example as compared with the example, and the accumulation of lead sulfate in the lower part of the negative electrode plate becomes apparent. This is considered to be because the effect of the height of the negative electrode plate is likely to become apparent.

The lead-acid battery according to one aspect of the present invention is applicable to control valve type and liquid type lead acid storage batteries, and is suitably used as a power source for industrial power storage devices such as electric vehicles (forklifts and the like). It can also be used as a power source for starting a car or a motorcycle.

Although the present invention has described preferred embodiments at this time, such disclosures should not be construed in a limited way. Various modifications and modifications will undoubtedly become apparent to those skilled in the art belonging to the present invention by reading the above disclosure. Accordingly, the appended claims should be construed to include all modifications and modifications without departing from the true spirit and scope of the invention.

1: Lead-acid battery 2: Negative electrode plate 3: Positive electrode plate 4: Separator 5a: Negative electrode strap 5b: Positive electrode strap 6a: Negative electrode column 6b: Positive electrode column 10: Electrode tank 11: Electrode plate group 12: Electrolyte

Claims (8)

It ’s a lead-acid battery.
The lead-acid battery includes a negative electrode plate, a positive electrode plate, and an electrolytic solution.
The negative electrode plate comprises a negative electrode current collector and a negative electrode material.
The negative electrode material contains an organic shrinkage proofing agent containing a sulfur element, and the negative electrode material contains.
The content of the sulfur element in the organic shrinkage proofing agent is 6000 μmol / g or more, and the content is 6000 μmol / g or more.
A lead-acid battery having a height of more than 10 cm on the negative electrode plate. The lead-acid battery according to claim 1, wherein the density of the negative electrode material is 2.5 g / cm ³ or more and 4.0 g / cm ³ or less. The negative electrode plate has an ear portion at the upper end portion of the negative electrode plate.
The lead-acid battery according to claim 1 or 2, wherein the selvage portion is located above the lead-acid battery with the lead-acid battery installed. The lead-acid battery according to any one of claims 1 to 3, wherein the height of the negative electrode plate is 100 cm or less. The lead-acid battery according to any one of claims 1 to 4, wherein the negative electrode current collector is a punched-out grid body. The lead-acid battery according to any one of claims 1 to 5, wherein the content of the sulfur element is 10,000 μmol / g or less. The lead-acid battery according to any one of claims 1 to 6, wherein the content of the organic shrink-proofing agent contained in the negative electrode electrode material is 0.01% by mass or more. The lead-acid battery according to any one of claims 1 to 7, wherein the content of the organic shrink-proofing agent contained in the negative electrode electrode material is 1.0% by mass or less.

Images