JP2022085748A - Lead acid battery - Google Patents

Abstract

SOLUTION: To provide a lead acid battery that includes at least one cell with an electrode plate group and an electrolyte, in which the electrode plate group includes a positive electrode plate, a negative electrode plate, and a separator interposed between the negative electrode plate and the positive electrode plate, the negative electrode plate includes a negative electrode material, the negative electrode material includes a cationic surfactant having one or more hydrophobic groups and hydrophilic groups, at least one of the hydrophobic groups is a long-chain aliphatic hydrocarbon group having 8 or more carbon atoms, and the content of the cationic surfactant in the negative electrode material is 10 ppm or more on a mass basis.SELECTED DRAWING: Figure 1

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. Lead-acid batteries include a negative electrode plate, a positive electrode plate, a separator (or mat), an electrolytic solution, and the like. Additives may be added to the constituent members of the lead-acid battery from the viewpoint of imparting various functions.

Patent Document 1 describes a group of electrode plates in which a negative electrode plate in which a negative electrode active material is filled in a negative electrode current collector and a positive electrode plate in which a positive electrode active material is filled in a positive electrode current collector are laminated via a separator. It is a liquid lead storage battery that has a structure housed in an electric tank together with an electrolytic solution, is charged intermittently, and is discharged at a high rate to a load in a partially charged state, and is at least a carbonaceous conductive material. And an organic compound that suppresses the coarsening of the negative electrode active material due to charging and discharging are added to the negative electrode active material, and the positive electrode plate is the total surface area of the positive electrode active material [m 3] per unit electrode group volume [cm ³ ]. ² ] is configured to be in the range of 3.5 to 15.6 [m ² / cm ³ ], and in addition, the electrolytic solution contains a cation-based flocculant, a cation-based surfactant, and the like. We are proposing a lead storage battery characterized by the addition of a compound selected from phosphoric acid.

Patent Document 2 proposes an electrolytic solution for a lead storage battery containing an ammonium compound represented by a specific formula (I).

Patent Document 3 is a rechargeable electrochemical cell that is subjected to a plurality of charge cycles and discharge cycles, and each charge cycle has a charging unit and a gassing charge corresponding to gassing charge in which gas is generated in the cell. Having a lower charge, the electrochemical cell is inactivated with a water-soluble electrolyte that is in ion contact with the electrodes and is placed in the electrolyte, supporting the current between the positive and negative electrodes. The inactivating means, which have an inhibitory means and its constituents bound to the negative electrode to form a barrier that inhibits gassing charge, are inactivated by the inactivating means of gassing when activated. It is activated by a charging unit corresponding to gassing charging so as to inhibit charging and limit gas generation in the cell, and when inactivated, it has no effect of substantially limiting charging. We propose an electrochemical cell in which the inactivating inhibitory means is inactivated by a lower charge than the gassing charge so that it has virtually no effect during the discharge cycle. Patent Document 3 describes quaternary ammonium such as alkyldimethylbenzylammonium chloride as an inactivating inhibitory means.

International Publication No. 2013/058058 Japanese Unexamined Patent Publication No. 2008-152973 U.S. Patent Application Publication No. 2002/0102467

Lead-acid batteries may be used in an undercharged state called a partially charged state (PSOC). For example, lead-acid batteries installed in idling stop start (ISS) vehicles are used in PSOC. When the lead-acid battery is repeatedly charged and discharged by PSOC, lead sulfate tends to accumulate and the life performance tends to deteriorate. In order to suppress the accumulation of lead sulfate, high charge acceptability is required. However, when the charge acceptability is high, the reduction reaction of hydrogen ions at the time of overcharging is also remarkable, so that the amount of overcharged electricity is large and the electrolytic solution is significantly reduced. When the surface of lead contained in the negative electrode material is covered with an organic additive, the reduction reaction of hydrogen ions during overcharging is less likely to occur, so that the amount of overcharged electricity can be reduced. However, when the surface of lead is covered with an organic additive, lead sulfate generated during discharge is less likely to elute during charging, and thus charge acceptability is lowered. Therefore, it is difficult to suppress the decrease in charge acceptability while reducing the amount of overcharged electricity.

One aspect of the present invention is a lead-acid battery.
The lead-acid battery comprises at least one cell comprising a group of plates and an electrolytic solution.
The electrode plate group includes a positive electrode plate, a negative electrode plate, and a separator interposed between the negative electrode plate and the positive electrode plate.
The negative electrode plate comprises a negative electrode material and is provided with a negative electrode material.
The negative electrode material contains a cationic surfactant having one or more hydrophobic groups and hydrophilic groups.
At least one of the hydrophobic groups is a long-chain aliphatic hydrocarbon group having 8 or more carbon atoms.
The present invention relates to a lead storage battery in which the content of the cationic surfactant in the negative electrode material is 10 ppm or more on a mass basis.

In lead-acid batteries, the amount of overcharged electricity can be reduced while ensuring relatively high charge acceptability.

It is an exploded perspective view which cut out a part which shows the appearance and the internal structure of the lead storage battery which concerns on one aspect of this invention.

Generally, in a lead storage battery, the reaction at the time of overcharging is greatly affected by the reduction reaction of hydrogen ions at the interface between lead and the electrolytic solution. When the negative electrode material of the lead storage battery contains an organic additive, the organic additive adheres to the surface of lead, which is an active material. When the surface of lead is covered with an organic additive, the reduction reaction of hydrogen ions is less likely to occur, so that the amount of overcharged electricity tends to decrease. However, the organic additive also adheres to the surface of lead sulfate generated during discharge, and lead sulfate is less likely to elute during charging, so that charge acceptability is lowered. Therefore, there is a trade-off relationship between suppressing the decrease in charge acceptability and reducing the amount of overcharged electricity, and it has been difficult to achieve both. Further, when the organic additive is unevenly distributed in the lead pores, it is necessary to increase the content of the organic additive in the negative electrode material in order to secure a sufficient effect of reducing the amount of overcharge electricity. There is. However, in general, when the content of the organic additive is increased, the charge acceptability is lowered.

In lead-acid batteries, an aqueous sulfuric acid solution is generally used as the electrolytic solution, so if an organic additive (oil, polymer, organic shrink-proofing agent, etc.) is contained in the negative electrode material, it will elute into the electrolytic solution and lead. It becomes difficult to balance with the adsorption of. For example, when an organic additive having low adsorptivity to lead is used, it becomes easy to elute into the electrolytic solution, and it becomes difficult to reduce the amount of overcharged electricity. On the other hand, when an organic additive having high adsorptivity to lead is used, it becomes difficult to attach the organic additive thinly to the lead surface, and the organic additive tends to be unevenly distributed in the pores of lead.

When the organic additive is unevenly distributed in the pores of lead, the movement of ions (lead ion, sulfate ion, etc.) is inhibited by the steric hindrance of the unevenly distributed organic additive. Therefore, the charge / discharge reaction is likely to be inhibited. When the content of the organic additive is increased in order to secure a sufficient effect of reducing the amount of overcharged electricity, the movement of ions in the pores is further inhibited, so that the charge / discharge reaction is further inhibited. When the charge / discharge reaction is inhibited, the charge acceptability is lowered and the discharge performance is lowered.

In view of the above, the lead-acid battery according to one aspect of the present invention includes at least one cell including a group of plates and an electrolytic solution. The electrode plate group includes a positive electrode plate, a negative electrode plate, and a separator interposed between the negative electrode plate and the positive electrode plate. The negative electrode plate comprises a negative electrode material. The negative electrode material contains a cationic surfactant having one or more hydrophobic groups and hydrophilic groups. At least one of the hydrophobic groups is a long-chain aliphatic hydrocarbon group having 8 or more carbon atoms. The content of the above-mentioned cationic surfactant in the negative electrode material is 10 ppm or more on a mass basis.
In the present specification, a cationic surfactant having one or more hydrophobic groups and hydrophilic groups, wherein at least one of the hydrophobic groups is a long-chain aliphatic hydrocarbon group having 8 or more carbon atoms. It may be referred to as a first surfactant.

In the lead storage battery according to one aspect of the present invention, the negative electrode electrode material contains a first surfactant in an amount of 10 ppm or more on a mass basis. With such a configuration, it is possible to reduce the amount of overcharged electricity while ensuring relatively high charge acceptability. By suppressing the generation of hydrogen during overcharging, the amount of decrease in the electrolytic solution can be reduced, which is advantageous for extending the life of the lead storage battery.

It is considered that the lead-acid battery according to one aspect of the present invention can reduce the amount of overcharged electricity while ensuring relatively high charge acceptability for the following reasons. First, high adsorptivity to lead can be ensured by the action of the hydrophilic group of the first surfactant. More specifically, in the negative electrode material, hydrogen sulfate ions having a negative charge are adsorbed on the surface of lead. Since the first surfactant has a cationic hydrophilic group, it exhibits high adsorptivity to the surface of lead. On the other hand, the action of a long-chain aliphatic hydrocarbon group having 8 or more carbon atoms suppresses excessive coating of the first surfactant on the lead surface. Therefore, a wide area of the surface of lead is thinly and widely covered with the first surfactant. As a result, the hydrogen overvoltage rises, and side reactions that generate hydrogen during overcharging are less likely to occur, so that the amount of overcharged electricity can be reduced. Even when the negative electrode material contains a very small amount of the first surfactant, the effect of reducing the amount of overcharged electricity can be obtained. Therefore, by including the first surfactant in the negative electrode material, lead can be obtained. It can be present in the vicinity, which is considered to exert a high adsorption action of the first surfactant on lead. Further, since the negative electrode material contains the first surfactant, the first surfactant tends to adhere to the surface of the lead sulfate generated at the time of discharge, so that the solubility of lead sulfate at the time of charging is lowered. Tend. However, since the thickness of the coating film of the first surfactant covering the surfaces of lead and lead sulfate is thin, the first surface activity is the dissolution of lead sulfate and the transfer of electrons when the lead ions are reduced to lead during charging. The degree of inhibition by the coating of the agent is reduced. Further, since the coating film of the first surfactant is thin and the uneven distribution is suppressed, the steric hindrance caused by the coating film of the first surfactant is reduced, so that the movement of lead ions in the pores of the negative electrode material is hindered. Is alleviated. Therefore, the high diffusion rate of lead ions is maintained. As a result, even when the negative electrode material contains the first surfactant which is an organic additive, it is possible to reduce the inhibition of the charge / discharge reaction, and it is considered that the decrease in charge acceptability is suppressed. ..

The effect of reducing the amount of overcharged electricity is exhibited by covering the surface of lead in the negative electrode material with the first surfactant. Therefore, it is important that the first surfactant is present in the vicinity of lead in the negative electrode material, whereby the effect of the first surfactant can be effectively exerted. Therefore, regardless of whether or not the first surfactant is contained in the components of the lead-acid battery other than the negative electrode material, the negative electrode material contains the first surfactant in a specific content as described above. It is important to be.

At least one of the hydrophobic groups of the first surfactant is preferably a long-chain aliphatic hydrocarbon group having 16 or more carbon atoms. In this case, the amount of overcharged electricity can be further reduced by increasing the adsorptivity to the lead surface.

Cationic surfactants are generally classified into amine salt type or quaternary ammonium salt type. The primary surfactant preferably contains a quaternary ammonium salt (in other words, a quaternary ammonium salt type cationic surfactant). When a quaternary ammonium salt is used, the amount of overcharge electricity can be further reduced because it exhibits higher adsorptivity to the lead surface than the amine salt due to its high cationic property.

The carbon number of the long-chain aliphatic hydrocarbon group in the first surfactant is preferably 26 or less. In this case, it is possible to secure higher adsorptivity of the first surfactant to the lead surface in the negative electrode material. Further, the negative electrode electrode material may contain a carbonaceous material, but when the carbon water of the long-chain aliphatic hydrocarbon group is 26 or less, the first surfactant is adsorbed on the carbonaceous material. It is reduced and adsorption to the lead surface is likely to occur. Therefore, the amount of overcharged electricity can be further reduced.

As described above, the first surfactant can thinly cover the lead surface while having high adsorptivity to lead due to the action of the hydrophilic group and the hydrophobic group of the first surfactant. Therefore, even if the content of the first surfactant in the negative electrode electrode material is small, the amount of overcharged electricity can be reduced. Further, even if the content is small, a sufficient effect of reducing the amount of overcharged electricity can be ensured, so that it is possible to suppress a decrease in charge acceptability. From the viewpoint of easily ensuring higher charge acceptability, the content of the first surfactant in the negative electrode electrode material is preferably 600 ppm or less on a mass basis. From the viewpoint of ensuring a higher effect of reducing the amount of overcharged electricity, the content of the first surfactant in the negative electrode electrode material is preferably 50 ppm or more.

In the present specification, the content of the first surfactant in the negative electrode electrode material is determined for the negative electrode plate taken out from the lead storage battery in a fully charged state.

In the lead storage battery, it is sufficient that the first surfactant can be contained in the negative electrode material in a predetermined content, and the origin of the first surfactant contained in the negative electrode material is not particularly limited. The first surfactant may be contained in any of the components of the lead-acid battery (for example, the negative electrode plate, the positive electrode plate, the electrolytic solution, and the separator) when the lead-acid battery is manufactured. The first surfactant may be contained in one component or in two or more components (for example, a negative electrode plate and an electrolytic solution).

The negative electrode material preferably contains a condensate of a bis-alene compound. The condensate of the bis-alene compound corresponds to an organic shrink proofing agent. When the negative electrode material contains an organic shrinkage proofing agent, high discharge performance can be easily obtained. Condensations of bis-alene compounds are generally classified as synthetic organic shrink proofing agents. When the negative electrode material contains a condensate of a bis-alene compound, the specific surface area of the negative electrode material increases, so that the amount of overcharged electricity tends to increase. However, even in such a case, the amount of overcharged electricity can be kept low by the action of the first surfactant. In addition, by using the condensate of the bis-alene compound, the uneven distribution of the lead of the organic shrinkage proofing agent on the surface is suppressed as compared with the case of using the lignin compound, so that higher charge acceptability can be easily obtained. Further, when a condensate of a bis-alene compound is used, deterioration of the negative electrode plate is suppressed even when the lead-acid battery is charged and discharged at a high temperature, and high discharge performance can be ensured.

The lead-acid battery may be either a control valve type (sealed type) lead-acid battery (VRLA type lead-acid battery) or a liquid type (vent type) lead-acid battery.

(Explanation of terms)
(Electrode material)
Each electrode material of the negative electrode material and the positive electrode material included in the positive electrode plate is usually held in the current collector. The electrode material is a portion of the electrode plate excluding the current collector. Members such as mats and pacing papers may be attached to the electrode plate. Since such a member (also referred to as a sticking member) is used integrally with the plate, it is included in the plate. When the electrode plate includes a sticking member (mat, pacing paper, etc.), the electrode material is a portion of the electrode plate excluding the current collector and the sticking member.

Among the positive electrode plates, the clad type positive electrode plate has a plurality of porous tubes, a core metal inserted in each tube, a current collecting portion for connecting the plurality of core metals, and a core metal inserted. It is provided with a positive electrode material filled in a tube and a collective punishment for connecting a plurality of tubes. In the clad type positive electrode plate, the positive electrode electrode material is a portion of the electrode plate excluding the tube, the core metal, the current collector, and the collective punishment. In the clad type positive electrode plate, the core metal and the current collector may be collectively referred to as a positive electrode current collector.

(Hydrophobic and hydrophilic groups of the first surfactant)
The first surfactant is a cationic surfactant. Therefore, the hydrophilic group of the first surfactant is a hydrophilic group that can be dissociated into a cation in the aqueous solution of the first surfactant. The hydrophobic group of the first surfactant is a functional group having a higher hydrophobicity than the hydrophilic group. At least one of the hydrophobic groups of the first surfactant may be a long-chain aliphatic hydrocarbon group having 8 or more carbon atoms.

(Organic shrinkage agent)
The organic shrink-proofing agent refers to an organic compound among compounds having a function of suppressing the shrinkage of lead, which is a negative electrode active material, when the lead storage battery is repeatedly charged and discharged. Organic shrink proofing agents often contain elemental sulfur.

(Sulfur element content in organic shrink proofing agent)
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.

(Condensation of bis-alene compound)
A condensate of a bis-alene compound is a condensate containing a unit of the bis-alene compound. The unit of the bis-alene compound means a unit derived from the bis-alene compound incorporated in the condensate. A bis-alene compound is a compound in which two sites each having an aromatic ring are linked via a single bond or a linking group.

(Weight average molecular weight)
In the present specification, the weight average molecular weight (Mw) is determined by GPC. The standard substance used when determining Mw is sodium polystyrene sulfonate.

(Fully charged)
The fully charged state of a liquid lead-acid battery is defined by the definition of JIS D 5301: 2019. More specifically, in a water tank at 25 ° C ± 2 ° C, the terminal voltage (V) during charging measured every 15 minutes or the electrolyte density converted to temperature at 20 ° C is three consecutive valid digits of three digits. The state in which the lead-acid battery is charged with a current (A) 0.2 times the numerical value (value in which the unit is Ah) described as the rated capacity is regarded as a fully charged state until a constant value is shown in. In the case of a control valve type lead-acid battery, the fully charged state is 0.2 times the current (value with Ah as the unit) described in the rated capacity in the air tank at 25 ° C ± 2 ° C (the unit is Ah). In A), constant current constant voltage charging of 2.23 V / cell is performed, and the charging current at the time of constant voltage charging is 0.005 times the value (value with the unit being Ah) described in the rated capacity (A). When it becomes, charging is completed.

A fully charged lead-acid battery is a fully charged lead-acid battery. The lead-acid battery may be fully charged after the chemical conversion, immediately after the chemical conversion, or after a lapse of time from the chemical conversion (for example, after the chemical conversion, the lead-acid battery in use (preferably at the initial stage of use) is fully charged. May be). An initial use battery is a battery that has not been used for a long time and has hardly deteriorated.

(Vertical direction of lead-acid battery or lead-acid battery component)
In the present specification, the vertical direction of the lead-acid battery or the component of the lead-acid battery (plate, battery case, separator, etc.) means the vertical direction of the lead-acid battery in the state where the lead-acid battery is used. Each electrode plate of the positive electrode plate and the negative electrode plate is provided with an ear portion for connecting to an external terminal. In some lead-acid batteries, such as horizontal control valve type lead-acid batteries, the ears are provided so as to project laterally to the sides of the plate, but in many lead-acid batteries, the ears are usually made of the plate. It is provided so as to project upward at the top.

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.

[Lead-acid battery]
(Negative electrode plate)
The negative electrode plate usually includes a negative electrode current collector in addition to the negative electrode material.

(Negative electrode current collector)
The negative electrode current collector may be formed by casting lead (Pb) or a lead alloy, or may be formed by processing a lead sheet or a lead alloy sheet. Examples of the processing method include expanding processing and punching processing. It is preferable to use a grid-shaped current collector as the negative electrode current collector because it is easy to support the negative electrode material.

The lead alloy used for the negative electrode current collector may be any of Pb—Sb based alloy, Pb—Ca based alloy, and Pb—Ca—Sn based 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 include a surface layer. The composition of the surface layer and the inner layer of the negative electrode current collector may be different. The surface layer may be formed on a part of the negative electrode current collector. The surface layer may be formed on the selvage portion of the negative electrode current collector. The surface layer of the selvage may contain Sn or Sn alloy.

(Negative electrode material)
The negative electrode material contains a first surfactant. The negative electrode material further contains a negative electrode active material (specifically, lead or lead sulfate) that develops a capacity by a redox reaction. The negative electrode material may contain at least one selected from the group consisting of organic shrink proofing agents, carbonaceous materials and other additives. Examples of the additive include barium sulfate, fibers (resin fibers and the like), and surfactants other than the first surfactant (also referred to as a second surfactant). However, the additives are not limited to these. The negative electrode active material in the charged state is spongy lead, but the unchemical negative electrode plate is usually produced by using lead powder.

(First surfactant)
The first surfactant, which is a cationic surfactant, is classified into an amine salt type and a quaternary ammonium salt type according to the type of hydrophilic group. In the first surfactant, the amine salt moiety or the quaternary ammonium salt moiety corresponds to a hydrophilic group. In the negative electrode material, the hydrophilic group may be present in a salt state or may be present in a cationic state. The type of anion forming the salt is not particularly limited, and examples thereof include a halide ion and an anion derived from an inorganic acid. Examples of the halide ion include fluoride ion, chloride ion, bromide ion, and iodide ion. Examples of the inorganic acid corresponding to the anion derived from the inorganic acid include hydrohalogenated acid (hydrogen hydrochloride, hydrobromic acid, etc.) or oxo acid (sulfuric acid, phosphoric acid, etc.).

The first surfactant usually has one hydrophilic group in one molecule. However, it is not intended to exclude the case where the first surfactant has a plurality of hydrophilic groups in one molecule.

The first surfactant has one or more hydrophobic groups in one molecule. The number of hydrophobic groups in the first surfactant may be one or more, and may be two or more or three or more. The amine salt type first surfactant can usually have one or more and three or less hydrophobic groups per nitrogen atom of the amine salt. A quaternary ammonium salt type primary surfactant may usually have four hydrophobic groups per nitrogen atom of the ammonium salt.

At least one of the hydrophobic groups of the first surfactant is a long-chain aliphatic hydrocarbon group having 8 or more carbon atoms. A long-chain aliphatic hydrocarbon group having 8 or more carbon atoms in the first surfactant may be referred to as a first hydrophobic group. The first surfactant may have one or more hydrophobic groups (also referred to as a second hydrophobic group) other than the first hydrophobic group.

The first surfactant may have one first hydrophobic group in one molecule, or may have two or more first hydrophobic groups. When the first surfactant has two or more first hydrophobic groups in one molecule, the kind of at least two first hydrophobic groups may be the same, and all the first hydrophobic groups It may be different. The upper limit of the number of first hydrophobic groups in the first surfactant is not particularly limited. In the amine salt type, the number of first hydrophobic groups is, for example, 3 or less, and may be 2 or less. In the quaternary ammonium salt type, the number of primary hydrophobic groups is, for example, 4 or less, and may be 3 or less or 2 or less.

In the amine salt type, the number of first hydrophobic groups contained in one molecule of the first surfactant is, for example, 1 to 3, may be 1 to 2, or may be 2 to 3. .. In the quaternary ammonium salt type, the number of first hydrophobic groups contained in one molecule of the first surfactant is, for example, 1 to 4, and may be 1 to 3 or 1 to 2. It may be ~ 4 or 2-3. When the first surfactant has two or more first hydrophobic groups, the effect of reducing the amount of overcharged electricity can be enhanced.

The first surfactant may have one second hydrophobic group or two or more. When the first surfactant has two or more second hydrophobic groups, the kind of at least two second hydrophobic groups may be the same, and all the second hydrophobic groups may be different. .. The upper limit of the number of the second hydrophobic groups is not particularly limited, and may be, for example, 2 or less in the amine salt type, and may be, for example, 3 or less or 2 or less in the quaternary ammonium salt type. In the first surfactant, the total number of the first hydrophobic group and the second hydrophobic group in one molecule does not exceed 3 in the amine salt type and 4 in the quaternary ammonium salt type per nitrogen atom. Will not be exceeded.

The first hydrophobic group may be a saturated hydrocarbon group or an unsaturated hydrocarbon group. The first hydrophobic group may be linear or branched. Examples of the first hydrophobic group include an alkyl group and an alkenyl group. The first hydrophobic group may be a dienyl group having two carbon-carbon double bonds, a trienyl group having three carbon-carbon double bonds, or the like. From the viewpoint that the thickness of the coating film of the first surfactant formed on the lead surface can be easily reduced, the first hydrophobic group is preferably an alkyl group or an alkenyl group.

The number of carbon atoms of the first hydrophobic group may be 8 or more. From the viewpoint that the thickness of the coating film of the first surfactant formed on the lead surface can be further reduced, the carbon number of the first hydrophobic group is preferably 10 or more, and may be 14 or more or 16 or more. It may be 18 or more. The number of carbon atoms of the first hydrophobic group is, for example, 30 or less. The carbon number of the first hydrophobic group is preferably 26 or less, preferably 24 or less or 22 or less, from the viewpoint that it is easy to secure high adsorptivity of the first surfactant to the lead surface due to the balance with the hydrophilic group. More preferred.

The number of carbon atoms of the first hydrophobic group is 8 or more and 30 or less (or 26 or less), 10 or more and 30 or less (or 26 or less), 14 or more and 30 or less (or 26 or less), 16 or more and 30 or less (or 26 or less), 18 or more and 30 or less (or 26 or less), 8 or more and 24 or less (or 22 or less), 10 or more and 24 or less (or 22 or less), 14 or more and 24 or less (or 22 or less), 16 or more and 24 or less (or 22 or less), Alternatively, it may be 18 or more and 24 or less (or 22 or less).

Specific examples of the alkyl group include 2-ethylhexyl, n-octyl, n-nonyl, n-decyl, i-decyl, lauryl (dodecyl), myristyl, cetyl, stearyl and behenyl. Specific examples of the alkenyl group include palmitrail and oleyl. The alkenyl group may be, for example, a C _2-30 alkenyl group or a C _2-26 alkenyl group, a C _2-24 alkenyl group, a C _2-22 alkenyl group, or a C. It may be a _10-22 alkenyl group.

Examples of the second hydrophobic group include a hydrocarbon group. Hydrocarbon groups also include hydrocarbon groups having substituents (eg, hydroxy groups, alkoxy groups, and / or carboxy groups). The hydrocarbon group may be any of an aliphatic, alicyclic, and aromatic group. The aliphatic hydrocarbon group is selected as a substituent from the group consisting of an aromatic hydrocarbon group (eg, phenyl group, trill group, naphthyl group) and an alicyclic hydrocarbon group (eg, cyclopentyl group, cyclohexyl group). May have at least one of them. Examples of the aliphatic hydrocarbon group having such a substituent include a benzyl group, a phenethyl group and a cyclohexylmethyl group. The carbon number of the aromatic hydrocarbon group and the alicyclic hydrocarbon group as the substituent is, for example, 5 or more and 20 or less, and may be 6 or more and 12 or less. The aromatic hydrocarbon group and the alicyclic hydrocarbon group may have an aliphatic hydrocarbon group (for example, an alkyl group, an alkenyl group, an alkynyl group) as a substituent. The number of carbon atoms of the aliphatic hydrocarbon group as a substituent may be, for example, 1 to 30, 1 to 20 or 1 to 10, and may be 1 to 6 or 1 to 4. ..

Examples of the aromatic hydrocarbon group include an aromatic hydrocarbon group having 24 or less carbon atoms (for example, 6 to 24). The number of carbon atoms of the aromatic hydrocarbon group may be 20 or less (for example, 6 to 20), 14 or less (for example, 6 to 14) or 12 or less (for example, 6 to 12). Examples of the aromatic hydrocarbon group include an aryl group and a bisaryl group. Examples of the aryl group include a phenyl group and a naphthyl group. Examples of the bisaryl group include a monovalent group corresponding to bisarene. Examples of the bisarene include biphenyl and bisaryl alkane (for example, bis C _6-10 aryl C _1-4 alkane (2,2-bisphenylpropane, etc.)).

Examples of the alicyclic hydrocarbon group include an alicyclic hydrocarbon group having 16 or less carbon atoms. The alicyclic hydrocarbon group may be a crosslinked cyclic hydrocarbon group. The alicyclic hydrocarbon group may have 10 or less or 8 or less carbon atoms. The alicyclic hydrocarbon group has, for example, 5 or more carbon atoms, and may be 6 or more carbon atoms.

The number of carbon atoms of the alicyclic hydrocarbon group may be 5 (or 6) or more and 16 or less, 5 (or 6) or more and 10 or less, or 5 (or 6) or more and 8 or less.

Examples of the alicyclic hydrocarbon group include a cycloalkyl group (cyclopentyl group, cyclohexyl group, cyclooctyl group, etc.) and a cycloalkenyl group (cyclohexenyl group, cyclooctenyl group, etc.). The alicyclic hydrocarbon group also includes the hydrogenated additive of the above aromatic hydrocarbon group.

Of the hydrocarbon groups, an aliphatic hydrocarbon group is preferable from the viewpoint that the first surfactant is thinly adhered to the lead surface. Examples of the aliphatic hydrocarbon group include an alkyl group, an alkenyl group, an alkynyl group, and a dienyl group. The aliphatic hydrocarbon group may be linear or branched.

The aliphatic hydrocarbon group has less than 8 carbon atoms and may be 7 or less or 6 or less. The lower limit of the number of carbon atoms is 1 or more for an alkyl group, 2 or more for an alkenyl group and an alkynyl group, and 3 or more for a dienyl group, depending on the type of the aliphatic hydrocarbon group. As the second hydrophobic group, an alkyl group and an alkenyl group (among others, an alkyl group) are preferable. The number of carbon atoms of the alkyl group is more preferably 4 or less, and may be 3 or less or 2 or less.

Specific examples of the alkyl group include methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, s-butyl, t-butyl, n-pentyl, neopentyl, i-pentyl, and s-pentyl. Examples thereof include 3-pentyl, t-pentyl and n-hexyl. Specific examples of the alkenyl group include vinyl, 1-propenyl, and allyl.

From the viewpoint that high adsorptivity to lead can be easily obtained due to high hydrophilicity, the first surfactant preferably contains at least a quaternary ammonium salt type first surfactant. The first surfactant may contain an amine salt type first surfactant in addition to the quaternary ammonium salt type first surfactant.

Examples of the quaternary ammonium salt type first surfactant include tetraalkylammonium salts and alkylbenzalkonium chloride. Examples of the tetraalkylammonium salt include a first surfactant having one first hydrophobic group (octyltrimethylammonium chloride, stearyltrimethylammonium chloride, cetyltrimethylammonium chloride, behenyltrimethylammonium chloride, etc.) and a first hydrophobic group. Examples thereof include a first surfactant having two (such as distearyldimethylammonium chloride). Examples of the alkylbenzalkonium chloride include stearylbenzyldimethylammonium chloride, stearyldimethylbenzylammonium chloride, and stearylbenzalkonium chloride. Examples of the amine salt type first surfactant include n-octylamine hydrochloride, dodecylamine hydrochloride and the like. These are merely examples, and the first surfactant is not limited to these specific examples.

The negative electrode electrode material may contain one kind of the first surfactant, or may contain two or more kinds.

The content of the first surfactant in the negative electrode electrode material may be, for example, 10 ppm or more on a mass basis. From the viewpoint of further enhancing the effect of reducing the amount of overcharged electricity, the content of the first surfactant in the negative electrode electrode material is preferably 50 ppm or more, more preferably 100 ppm or more, and 150 ppm or more or 250 ppm or more on a mass basis. More preferably, it may be 300 ppm or more. The content of the first surfactant in the negative electrode electrode material is, for example, 1000 ppm or less, and may be 700 ppm or less on a mass basis. From the viewpoint of easily ensuring higher charge acceptability, the content of the first surfactant in the negative electrode electrode material is preferably 600 ppm or less or 500 ppm or less, and more preferably 400 ppm or less or 300 ppm or less on a mass basis.

The content of the first surfactant in the negative electrode electrode material is 10 ppm or more and 1000 ppm or less (or 700 ppm or less), 50 ppm or more and 1000 ppm or less (or 700 ppm or less), 100 ppm or more and 1000 ppm or less (or 700 ppm or less), and 150 ppm on a mass basis. More than 1000ppm (or 700ppm or less), 250ppm or more and 1000ppm or less (or 700ppm or less), 300ppm or more and 1000ppm or less (or 700ppm or less), 10ppm or more and 600ppm or less (or 500ppm or less), 50ppm or more and 600ppm or less (or 500ppm or less), 100ppm 600 ppm or less (or 500 ppm or less), 150 ppm or more and 600 ppm or less (or 500 ppm or less), 250 ppm or more and 600 ppm or less (or 500 ppm or less), 300 ppm or more and 600 ppm or less (or 500 ppm or less), 10 ppm or more and 400 ppm or less (or 300 ppm or less), 50 ppm It may be 400 ppm or more (or 300 ppm or less), 100 ppm or more and 400 ppm or less (or 300 ppm or less), 150 ppm or more and 400 ppm or less (or 300 ppm or less), 250 ppm or more and 400 ppm or less (or 300 ppm or less), or 300 ppm or more and 400 ppm or less.

(Second surfactant)
The negative electrode material may contain a second surfactant other than the first surfactant. Examples of the second surfactant include cationic surfactants other than the first surfactant, nonionic surfactants, anionic surfactants, and amphoteric surfactants. The negative electrode material may contain one kind of the second surfactant, or may contain two or more kinds.

The ratio of the first surfactant to the total surfactant contained in the negative electrode electrode material is preferably large, for example, 70% by mass or more of the total surfactant, 80% by mass or more, or 90% by mass or more. good. The ratio of the first surfactant to the total surfactant is 100% by mass or less. The negative electrode material may contain only the first surfactant as the surfactant.

(Organic shrinkage agent)
Organic shrinkage proofing agents are usually roughly classified into lignin compounds and synthetic organic shrinkage proofing agents. It can be said that the synthetic organic shrinkage proofing agent is an organic shrinkage proofing agent other than the lignin compound. Examples of the organic shrinkage proofing agent contained in the negative electrode electrode material include lignin compounds and synthetic organic shrinkage proofing agents. The negative electrode electrode material may contain one kind of organic shrinkage proofing agent, or may contain two or more kinds of organic shrinkage proofing agents.

Examples of the lignin compound include lignin and lignin derivatives. Examples of the lignin derivative include lignin sulfonic acid or a salt thereof (alkali metal salt (sodium salt, etc.), etc.).

The synthetic 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.

At least a lignin compound may be used as the organic shrinkage proofing agent. Lignin compounds tend to have lower charge acceptability than synthetic organic shrink proofing agents. However, since the negative electrode material contains the first surfactant, high charge acceptability can be ensured even when a lignin compound is used as the organic shrinkage proofing agent.

As the organic shrinkage proofing agent, it is also preferable to use a condensate containing at least a unit of an aromatic compound. Examples of such a condensate include a condensate of an aromatic compound made of an aldehyde compound (such as at least one selected from the group consisting of aldehydes (eg, formaldehyde) and condensates thereof). The organic shrinkage proofing agent may contain a unit of one kind of aromatic compound, or may contain a unit of two or more kinds of aromatic compounds.
The unit of the aromatic compound means a unit derived from the aromatic compound incorporated in the condensate.

Examples of the aromatic ring contained in the aromatic compound include a benzene ring and a naphthalene ring. When the aromatic compound 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 (including an alkylidene group), a sulfone group) or the like. Examples of such a structure include a bisarene structure (biphenyl, bisphenylalkane, bisphenylsulfone, etc.). Examples of the aromatic compound include compounds having the above aromatic ring and at least one selected from the group consisting of a hydroxy group and 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 an amino group. The hydroxy group also includes a salt of the hydroxy group (-OMe). The amino group also includes a salt of the amino group (specifically, a salt with an anion). Examples of Me include alkali metals (Li, K, Na, etc.), Group 2 metals of the periodic table (Ca, Mg, etc.) and the like.

Examples of the aromatic compound include bisarene compounds [bisphenol compounds, hydroxybiphenyl compounds, bisarene compounds having an amino group (bisarylalkane compounds having an amino group, bisarylsulfone compounds having an amino group, biphenyl compounds having an amino group, etc.), and the like. Hydroxyarene compounds (hydroxynaphthalene compounds, phenol compounds, etc.), aminoarene compounds (aminonaphthalene compounds, aniline compounds (aminobenzenesulfonic acid, alkylaminobenzenesulfonic acid, etc.), etc.), etc.] are preferable. The aromatic compound 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. When the negative electrode material contains a condensate of a bis-alene compound (such as a condensate of an aldehyde compound), it is possible to secure higher charge acceptability while keeping the amount of overcharge electricity low.

The condensate preferably contains at least a unit of an aromatic compound having a sulfur-containing group. Above all, it is advantageous to use a condensate containing at least a unit of a bisphenol compound having a sulfur-containing group in order to secure higher charge acceptability. From the viewpoint of enhancing the effect of reducing the amount of overcharged electricity, it is also preferable to use a condensate of a naphthalene compound having an aldehyde compound having a sulfur-containing group and at least one selected from the group consisting of a hydroxy group and an amino group. ..

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. The sulfur-containing group is not particularly limited, and examples thereof include a sulfonyl group, a sulfonic acid group, or a salt thereof.

Further, as the organic shrinkage proofing agent, for example, a condensation containing at least one selected from the group consisting of a unit of the above-mentioned bisarene compound and a unit of a monocyclic aromatic compound (hydroxyarene compound and / or aminoarene compound, etc.). At least one may be used. The organic shrinkage proofing agent may contain at least a condensate containing a unit of a bisarene compound and a unit of a monocyclic aromatic compound (particularly, a hydroxyarene compound). Examples of such a condensate include a condensate of a bis-alene compound and a monocyclic aromatic compound made of an aldehyde compound. As the hydroxyarene compound, a phenol sulfonic acid compound (such as phenol sulfonic acid or a substitute thereof) is preferable. As the aminoarene compound, aminobenzenesulfonic acid, alkylaminobenzenesulfonic acid and the like are preferable. As the monocyclic aromatic compound, a hydroxyarene compound is preferable.

Among the above-mentioned organic shrinkage proofing agents, the negative electrode electrode material may contain, for example, an organic shrinkage proofing agent (first organic shrinkage proofing agent) having a sulfur element content of 2000 μmol / g or more. Examples of the first organic shrinkage proofing agent include the above-mentioned synthetic organic shrinkage proofing agent (the above-mentioned condensate and the like).

The sulfur element content of the first organic shrinkage proofing agent may be 2000 μmol / g or more, and preferably 3000 μmol / g or more. The upper limit of the sulfur element content of the first organic shrinkage proofing agent is not particularly limited. From the viewpoint of further enhancing the effect of reducing the amount of overcharged electricity, the sulfur element content of the first organic shrinkage proofing agent is preferably 9000 μmol / g or less, and more preferably 8000 μmol / g or less.

Even if the sulfur element content of the first organic shrinkage proofing agent is, for example, 2000 μmol / g or more (or 3000 μmol / g or more) 9000 μmol / g or less, or 2000 μmol / g or more (or 3000 μmol / g or more) 8000 μmol / g or less. good.

The first organic shrinkage proofing agent contains a condensate containing a unit of an aromatic compound having a sulfur-containing group, and the condensate may contain at least a unit of a bisarene compound (such as a bisphenol compound) as a unit of the aromatic compound.

The weight average molecular weight (Mw) of the first organic shrinkage proofing agent is preferably 7,000 or more. The Mw of the first organic shrinkage proofing agent is, for example, 100,000 or less, and may be 20,000 or less.

The negative electrode material can contain, for example, an organic shrinkage proofing agent (second organic shrinkage proofing agent) having a sulfur element content of less than 2000 μmol / g. Examples of the second organic shrinkage proofing agent include lignin compounds and synthetic organic shrinkage proofing agents (particularly, lignin compounds) among the above-mentioned organic shrinkage proofing agents. The sulfur element content of the second organic shrinkage proofing agent is preferably 1000 μmol / g or less, and may be 800 μmol / g or less. The lower limit of the sulfur element content in the second organic shrinkage proofing agent is not particularly limited, and is, for example, 400 μmol / g or more.

The Mw of the second organic shrinkage proofing agent is, for example, less than 7000. The Mw of the second organic shrinkage proofing agent is, for example, 3000 or more.

The negative electrode electrode material may contain a second organic shrinkage proofing agent in addition to the first organic shrinkage proofing agent. When the first organic shrinkage proofing agent and the second organic shrinkage proofing agent are used in combination, the mass ratios thereof can be arbitrarily selected.

The content of the organic shrinkage-proofing agent contained in the negative electrode electrode material is, for example, 0.005% by mass or more, and may be 0.01% by mass or more. When the content of the organic shrink proofing agent is in such a range, a high discharge capacity can be ensured. The content of the organic shrinkage proofing agent is, for example, 1.0% by mass or less, and may be 0.5% by mass or less. From the viewpoint of further enhancing the effect of suppressing the decrease in charge acceptability, the content of the organic shrinkage proofing agent is preferably 0.3% by mass or less, more preferably 0.25% by mass or less.

The content of the organic shrinkage barrier contained in the negative electrode electrode material is 0.005% by mass or more (or 0.01% by mass) 1.0% by mass or less, 0.005% by mass or more (or 0.01% by mass). (More than) 0.5% by mass or less, 0.005% by mass or more (or 0.01% by mass or more) 0.3% by mass or less, or 0.005% by mass or more (or 0.01% by mass or more) 0.25 It may be mass% or less.

(Carbonaceous material)
As the carbonaceous material contained in the negative electrode electrode material, carbon black, graphite, hard carbon, soft carbon and the like can be used. Examples of carbon black include acetylene black, furnace black, and lamp black. Furness Black also includes Ketjen Black (trade name).

In the present specification, among carbonaceous materials, a peak (D band) appearing in the range of 1300 cm ^-1 or more and 1350 cm ^-1 or less in the Raman spectrum and a peak (G band) appearing in the range of 1550 cm ^-1 or more and 1600 cm ^-1 or less. A carbonaceous material having an I _D / _IG strength ratio of 0 or more and 0.9 or less is referred to as graphite. The graphite may be either artificial graphite or natural graphite.

The negative electrode material may contain one kind of carbonaceous material, or may contain two or more kinds of carbonaceous material.

Since the first surfactant also covers the surface of the carbonaceous material, the coating amount on lead and lead sulfate is also affected by the specific surface area and amount of the carbonaceous material.

The specific surface area of the carbonaceous material is, for example, 0.5 (m ² · g ^-1 ) or more, even if it is 1 (m ² · g ^-1 ) or more or 20 (m ² · g ^-1 ) or more. good. When the specific surface area is in such a range, it is easy to prevent the content of the first surfactant from becoming excessively large, and it is easy to secure high charge acceptability. The specific surface area of the carbonaceous material may be 300 (m ² · g ^-1 ) or more or 400 (m ² · g ^-1 ) or more. When the specific surface area is in such a range, the amount of overcharged electricity tends to be large, but even in such a case, the amount of overcharged electricity can be reduced by combining with the first surfactant. The specific surface area of the carbonaceous material is, for example, 1500 (m ² · g ^-1 ) or less, may be 1000 (m ² · g ^-1 ) or less, and 800 (m ² · g ^-1 ) or less. It may be 200 (m ² · g ^-1 ) or less or 150 (m ² · g ^-1 ) or less. When the specific surface area is in such a range, the effect of reducing the amount of overcharged electricity can be further enhanced.

The specific surface area of the carbonaceous material is 0.5 (m ² · g ^-1 ) or more and 1500 (m ² · g ^-1 ) or less (or 1000 (m ² · g ^-1 ) or less), 1 (m ² · g). ^-1 ) or more and 1500 (m ²・ g ^-1 ) or less (or 1000 (m ²・ g ^-1 ) or less), 20 (m ²・ g ^-1 ) or more and 1500 (m ²・ g ^-1 ) or less (or 1000 (m ² · g ^-1 ) or less), 300 (m ² · g ^-1 ) or more 1500 (m ² · g ^-1 ) or less (or 1000 (m ² · g ^-1 ) or less), 400 (m ² )・ G ^-1 ) or more and 1500 (m ²・ g ^-1 ) or less (or 1000 (m ²・ g ^-1 ) or less), 300 (m ²・ g ^-1 ) or more (or 400 (m ²・ g ^-1 ) or less) ) Or more) 800 (m ² · g ^-1 ) or less, 0.5 (m ² · g ^-1 ) or more and 800 (m ² · g ^-1 ) or less (or 200 (m ² · g ^-1 ) or less), 1 (m ²・ g ^-1 ) or more and 800 (m ²・ g ^-1 ) or less (or 200 (m ²・ g ^-1 ) or less), 20 (m ²・ g ^-1 ) or more and 800 (m ²・ g) ^-1 ) or less (or 200 (m ²・ g ^-1 ) or less), 0.5 (m ²・ g ^-1 ) or more and 150 (m ²・ g ^-1 ) or less, 1 (m ²・ g ^-1 ) It may be 150 (m ² · g ^-1 ) or less, or 20 (m ² · g ^-1 ) or more and 150 (m ² · g ^-1 ) or less.

The specific surface area of the carbonaceous material is the BET specific surface area obtained by the gas adsorption method using nitrogen gas.

The content of the carbonaceous material in the negative electrode electrode material is, for example, 0.05% by mass or more, and may be 0.10% by mass or more. The content of the carbonaceous material is, for example, 5% by mass or less, and may be 3% by mass or less.

The content of the carbonaceous material in the negative electrode material is 0.05% by mass or more and 5% by mass or less, 0.05% by mass or more and 3% by mass or less, 0.10% by mass or more and 5% by mass or less, or 0.10. It may be mass% or more and 3 mass% or less.

(Barium sulfate)
The content of barium sulfate in the negative electrode electrode material is, for example, 0.05% by mass or more, and may be 0.10% by mass or more. The content of barium sulfate in the negative electrode electrode material is, for example, 3% by mass or less, and may be 2% by mass or less.

The content of barium sulfate in the negative electrode material is 0.05% by mass or more and 3% by mass or less, 0.05% by mass or more and 2% by mass or less, 0.10% by mass or more and 3% by mass or less, or 0.10% by mass. It may be% or more and 2% by mass or less.

(Analysis of negative electrode material or constituents)
The method of analyzing the negative electrode material or its constituent components will be described below. Prior to measurement or analysis, a fully charged lead-acid battery is disassembled to obtain a negative electrode plate to be analyzed. The obtained negative electrode plate is washed with water to remove sulfuric acid from the negative electrode plate. Wash with water by pressing the pH test paper against the surface of the negative electrode plate washed with water until it is confirmed that the color of the test paper does not change. However, the time for washing with water shall be within 2 hours. The negative electrode plate washed with water is dried at 60 ± 5 ° C. for about 6 hours in a reduced pressure environment. If the negative electrode plate contains a sticking member after drying, the sticking member is removed by peeling. Next, a sample (hereinafter referred to as sample A) is obtained by separating the negative electrode material from the negative electrode plate. Sample A is pulverized as needed and subjected to analysis.

(1) Analysis of surfactant (1-1) Qualitative analysis of first surfactant The crushed sample A is used. Approximately 1 g of Sample A is taken, weighed accurately and 5 mL of chloroform is added to prepare the mixture. The first surfactant is extracted by stirring the mixture at 20 ± 5 ° C. with ultrasonic waves for 5.5 hours. Then, the filtrate is collected by filtration, and the solid content and the container separated by filtration are washed with chloroform to collect the washing liquid. The filtrate and washings are mixed and concentrated with nitrogen gas.

At least one selected from infrared spectroscopic spectrum, ultraviolet visible absorption spectrum, NMR spectrum, liquid chromatograph / mass spectrometry (LC / MS) and thermal decomposition gas chromatograph / mass spectrometry (GC / MS) for the resulting concentrate. By obtaining information from, the first surfactant is identified. As for the counter anion of the cationic surfactant, since ion exchange may occur in sulfuric acid, a structure other than the counter anion will be specified.

(1-2) Quantitative analysis of the first surfactant The concentrate obtained by the same procedure as in (1-1) above is diluted with chloroform until the volume of the solution reaches 10 mL. In this way, a sample for analysis (sample B) is prepared.

Using the sample B, the content of the first surfactant in the negative electrode electrode material is quantified by LC / MS analysis using the SRM (selected reaction monitoring) method. More specifically, the LC / MS spectrum of sample B is measured, and the concentration of the first surfactant in sample B is determined by the calibration curve method from the peak intensity of the characteristic specific peak of the first surfactant. Ask. Then, the content of the first surfactant in the negative electrode electrode material is determined from the required concentration and the mass of the sample A collected at the time of preparing the sample B. For the calibration curve showing the relationship between the peak intensity of a specific peak and the concentration of the first surfactant in the analysis data, the first surfactant specified by qualitative analysis was prepared separately, and this first surfactant was prepared separately. Is created in advance using. For example, when the first surfactant is behenyltrimethylammonium chloride, a peak characteristic of m / z = 368.5 in the LC / MS spectrum is detected. LC / MS analysis is performed under the following conditions.

LC / MS device: LC unit (manufactured by Agilent Technologies, 1200 Series), MS unit (manufactured by Agilent Technologies 6140)
Column: United UK-C18 UP made by Imtakat (inner diameter 2 mm, length 10 cm)
Column temperature: 50 ° C ± 1 ° C
Mobile phase: Using a mixture of the first solution and the second solution, gradually change the mixing ratio of the first solution and the second solution from 20:80 (volume ratio) to 0: 100 (volume ratio) over 3 minutes. Change and use only the second solution after 3 to 10 minutes.
First solution = aqueous solution containing 10 mmol / L concentration of ammonium formate and 10 mmol / L concentration of formic acid Second solution = methanol solution containing 10 mmol / L concentration of ammonium formate and 10 mmol / L formic acid Flow velocity: 0.4 mL / min
Sample B injection volume: 1 μL
Detector: MS (ESI positive)
Measurement mode: SCAN (mass measurement range: m / z = 100 to 1000)

(2) Analysis of organic shrinkage proofing agent (2-1) Qualitative analysis of organic shrinkage proofing agent in negative electrode material The crushed sample A is immersed in a 1 mol / L sodium hydroxide aqueous solution to extract the organic shrinkage proofing agent. Next, the first organic shrinkage proofing agent and the second organic shrinkage proofing agent are separated from the extract, if necessary. For each of the isolates containing each organic shrinkant, the insoluble components are filtered off, the resulting solution is desalted, then concentrated and dried. Desalination is performed using a desalting column, by passing the solution through an ion exchange membrane, or by placing the solution in a dialysis tube and immersing it in distilled water. By drying this, a powder sample of an organic shrinkage proofing agent (hereinafter referred to as sample C) can be obtained.

The infrared spectroscopic spectrum measured using the sample C of the organic shrinkage proofing agent thus obtained, the ultraviolet visible absorption spectrum measured by diluting the sample C with distilled water or the like, and the sample C being used as heavy water or the like. Combining the NMR spectrum of the solution obtained by dissolving in a predetermined solvent or the information obtained from thermal decomposition GC / MS or the like capable of obtaining information on the individual compounds constituting the substance, the organic shrinkage proofing agent Identify the type.

The separation of the first organic shrinkage proofing agent and the second organic shrinkage proofing agent from the above extract is carried out as follows. First, the extract is measured by infrared spectroscopy, NMR, and / or GC / MS to determine whether or not it contains a plurality of organic shrink proofing agents. Next, the molecular weight distribution is measured by GPC analysis of the extract, and if a plurality of organic shrink-proofing agents can be separated by molecular weight, the organic shrinkage-proofing agents are separated by column chromatography based on the difference in molecular weight. When separation due to the difference in molecular weight is difficult, one of the organic shrinkage proofing agents is separated by a precipitation separation method by utilizing the difference in solubility which differs depending on the type of functional group and / or the amount of functional groups of the organic shrinkage proofing agent. Specifically, one of the organic shrink-proofing agents is aggregated and separated by adding a sulfuric acid aqueous solution to a mixture in which the above extract is dissolved in a NaOH aqueous solution and adjusting the pH of the mixture. The insoluble component is removed by filtration from the mixture in which the separated product is dissolved again in the aqueous NaOH solution as described above. Also, the remaining solution after separating one of the organic shrink proofing agents is concentrated. The obtained concentrate contains the other organic shrink-proofing agent, and the insoluble component is removed from the concentrate by filtration as described above.

(2-2) Quantification of the content of the organic shrinkage proofing agent in the negative electrode electrode material In the same manner as in (2-1) above, a solution is obtained after removing insoluble components from each of the separated substances containing the organic shrinkage proofing agent by filtration. .. The ultraviolet-visible absorption spectrum is measured for each of the obtained solutions. The content of each organic shrinkage proofing agent in the negative electrode electrode material is determined by using the peak intensity characteristic of each organic shrinkage proofing agent 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 shrink-proof agent extracted from the negative electrode of the battery and a separately available organic polymer having a similar shape in the ultraviolet-visible absorption spectrum, infrared spectroscopic spectrum, NMR spectrum, and the like. By creating a line, the content of the organic shrink-proofing agent is 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 sample C 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 sample C in the flask containing the adsorbent, an eluate in which sulfate ions are dissolved in the adsorbent is obtained. Next, the content (c1) of the sulfur element in 0.1 g of the organic shrink-proofing agent is determined by titrating the eluate with barium perchlorate using thorin as an indicator. Next, c1 is multiplied by 10 to calculate the content of sulfur element (μmol / g) in the organic shrinkage proofing agent per 1 g.

(2-4) Mw measurement of the organic shrinkage proofing agent In the same manner as in (2-1) above, after obtaining the sample C of the organic shrinkage proofing agent, GPC measurement of the organic shrinkage proofing agent is performed using the following device under the following conditions. conduct. Separately, a calibration curve (calibration curve) is created from the plot of Mw of the standard substance and the elution time. Based on this calibration curve and the GPC measurement result of the organic shrinkage proofing agent, Mw of the organic shrinkage proofing agent is calculated.

GPC device: Build-up GPC system SD-8022 / DP-8020 / AS-8020 / CO-8020 / UV-8020 (manufactured by Tosoh Corporation)
Column: TSKgel G4000SWXL, G2000SWXL (7.8 mm ID x 30 cm) (manufactured by Tosoh Corporation)
Detector: UV detector, λ = 210nm
Eluent: A mixed solution of NaCl aqueous solution with a concentration of 1 mol / L: acetonitrile (volume ratio = 7: 3) Flow velocity: 1 mL / min.
Concentration: 10 mg / mL
Injection volume: 10 μL
Standard substance: Na polystyrene sulfonate (Mw = 275,000, 35,000, 12,500, 7,500, 5,200, 1,680)

(3) Analysis of carbonaceous material (3-1) Separation and quantification of carbonaceous material Crushed sample A is used. To 5 g of sample A, 30 mL of a 60% by mass nitric acid aqueous solution is added, and the mixture is heated at 70 ° C. ± 5 ° C. Further, 10 g of disodium ethylenediaminetetraacetate, 30 mL of 28% by mass concentration of ammonia water, and 100 mL of water are added to 5 g of the sample A, and heating is continued to dissolve the soluble component. The sample thus pretreated is collected by filtration. The collected sample is sieved with a mesh opening of 500 μm to remove components having a large size such as a reinforcing material, and the components that have passed through the sieve are recovered as a carbonaceous material.

The content of the carbonaceous material in the negative electrode electrode material is determined by measuring the mass of the carbonaceous material separated by the above procedure and calculating the ratio (mass%) of the total mass to the pulverized sample. ..

(3-2) BET specific surface area of carbonaceous material The BET specific surface area of carbonaceous material is determined by using the BET formula by the gas adsorption method using the carbonaceous material separated by the procedure of (3-1) above. Desired. The carbonaceous material is pretreated by heating in a nitrogen flow at a temperature of 150 ° C. for 1 hour to remove water. Using the pretreated carbonaceous material, the BET specific surface area of the carbonaceous material is determined by the following equipment under the following conditions.
Measuring device: TriStar3000 manufactured by Micromeritics
Adsorption gas: Nitrogen gas with a purity of 99.99% or more Adsorption temperature: Liquid nitrogen boiling temperature (77K)
BET specific surface area calculation method: Compliant with JIS Z 8830: 2013 7.2

(4) Quantification of barium sulfate To 10 g of crushed sample A, 50 ml of nitric acid having a concentration of 20% by mass is added and heated for about 20 minutes to dissolve the lead component as lead ions. The resulting solution is filtered to filter out solids such as carbonaceous materials and barium sulfate.

After the obtained solid content is dispersed in water to form a dispersion liquid, a carbonaceous material and components other than barium sulfate (for example, a reinforcing material) are removed from the dispersion liquid using a sieve. Next, the dispersion liquid is suction-filtered using a membrane filter whose mass has been measured in advance, and the membrane filter is dried together with the filtered sample in a dryer at 110 ° C. ± 5 ° C. The filtered sample is a mixed sample of carbonaceous material and barium sulfate. The mass of the sample D (M _m ) is measured by subtracting the mass of the membrane filter from the total mass of the dried mixed sample (hereinafter referred to as sample D) and the membrane filter. Then, the sample D is put into a crucible together with a membrane filter and incinerated at 1300 ° C. or higher. The remaining residue is barium oxide. The mass of barium oxide is converted into the mass of barium sulfate to obtain the mass of barium sulfate ( _MB ).

(others)
The negative electrode plate can be formed by applying or filling a negative electrode paste to a negative electrode current collector, aging and drying to produce an unchemical negative electrode plate, and then forming an unchemical negative electrode plate. The negative electrode paste is, for example, a lead powder, a first surfactant, and if necessary, at least one selected from the group consisting of an organic shrinkage proofing agent, a carbonaceous material, and other additives, and water and sulfuric acid ( Alternatively, it is prepared by adding (or aqueous sulfuric acid) and kneading. At the time of aging, 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)
The positive electrode plate of a lead storage battery can be classified into a paste type, a clad type and the like. Either a paste type or a clad type positive electrode plate may be used. The paste type positive electrode plate includes a positive electrode current collector and a positive electrode material. The configuration of the clad type positive electrode plate is as described above.

The positive electrode current collector may be formed by casting lead (Pb) or a lead alloy, or may be formed by processing a lead sheet or a lead alloy sheet. Examples of the processing method include expanding processing and punching processing. It is preferable to use a grid-shaped current collector as the positive electrode current collector because it is easy to support the positive electrode material.

As the lead alloy used for the positive electrode current collector, Pb-Sb-based alloys, 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 include a surface layer. The composition of the surface layer and the inner layer of the positive electrode current collector may be different. The surface layer may be formed on a part of the positive electrode current collector. The surface layer may be formed only on the lattice portion, the ear portion, or the frame bone portion of the positive electrode current collector.

The positive electrode material contained in the positive electrode plate contains a positive electrode active material (lead dioxide or lead sulfate) whose capacity is developed by a redox reaction. The positive electrode material may contain other additives, if necessary.

The unchemical paste type positive electrode plate is obtained by filling a positive electrode current collector with a positive electrode paste, aging and drying. The positive electrode paste is prepared by kneading lead powder, additives, water, and sulfuric acid. The unchemical clad type positive electrode plate is formed by filling a porous tube into which a core metal connected at a current collecting part is inserted with lead powder or slurry-like lead powder, and connecting a plurality of tubes in a collective punishment. Will be done. Then, a positive electrode plate is obtained by forming these unchemical positive electrode plates.

The chemical conversion can be carried out by charging the electrode plate group in a state where the electrode plate group including the unchemical positive 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.

(Separator)
A separator can be arranged between the negative electrode plate and the positive electrode plate. As the separator, at least one selected from a non-woven fabric and a microporous membrane is used.

Nonwoven fabric is a mat that is entwined without weaving fibers, and is mainly composed of fibers. In the non-woven fabric, for example, 60% by mass or more of the non-woven fabric is formed of fibers. As the fiber, glass fiber, polymer fiber (polyolefin fiber, acrylic fiber, polyester fiber (polyethylene terephthalate fiber, etc.), etc.), pulp fiber, and the like can be used. Of these, glass fiber is preferable. The nonwoven fabric may contain components other than fibers (for example, acid-resistant inorganic powder, 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 is extruded into a sheet and then the pore-forming agent is removed to form pores. It is obtained by. The microporous membrane is preferably composed of a material having acid resistance, and a microporous membrane mainly composed of a polymer component is preferable. As the polymer component, polyolefin (polyethylene, polypropylene, etc.) is preferable. Examples of the pore-forming agent include at least one selected from the group consisting of polymer powders and oils.

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

The separator may be in the shape of a sheet or in the shape of a bag. A sheet-shaped separator may be sandwiched between the positive electrode plate and the negative electrode plate. Further, the electrode plate may be arranged so as to sandwich the electrode plate with one sheet-shaped separator in a bent state. In this case, the positive electrode plate sandwiched between the bent sheet-shaped separators and the negative electrode plate sandwiched between the bent sheet-shaped separators may be overlapped, and one of the positive electrode plate and the negative electrode plate may be sandwiched between the bent sheet-shaped separators. , May be overlapped with the other electrode plate. Further, the sheet-shaped separator may be bent in a bellows shape, and the positive electrode plate and the negative electrode plate may be sandwiched between the bellows-shaped separators so that the separator is interposed between them. When using a separator bent in a bellows shape, the separator may be arranged so that the bent portion is along the horizontal direction of the lead storage battery (for example, the bent portion is parallel to the horizontal direction), or along the vertical direction. (For example, the separator may be arranged so that the bent portion is parallel to the vertical direction). In the bellows-shaped separator, recesses are alternately formed on both main surface sides of the separator. Since the ear portion is usually formed on the upper part of the positive electrode plate and the negative electrode plate, when the separator is arranged so that the bent portion is along the horizontal direction of the lead storage battery, the positive electrode plate is formed only in the concave portion on one main surface side of the separator. And a negative electrode plate is arranged (that is, a double separator is interposed between the adjacent positive electrode plate and the negative electrode plate). When the separator is arranged so that the bent portion is along the vertical direction of the lead storage battery, the positive electrode plate can be accommodated in the recess on one main surface side and the negative electrode plate can be accommodated in the recess on the other main surface side (that is,). , The separator can be in a single interposition between the adjacent positive electrode plate and the negative electrode plate). When a bag-shaped separator is used, the bag-shaped separator may accommodate a positive electrode plate or a negative electrode plate.

(Electrolytic solution)
The electrolytic solution is an aqueous solution containing sulfuric acid, and may be gelled if necessary.
The electrolytic solution may contain the above-mentioned first surfactant.

The electrolyte may optionally contain cations (eg, metal cations) and / or anions (eg, anions other than sulfate anions (such as phosphate ions)). Examples of the metal cation include at least one selected from the group consisting of Na ion, Li ion, Mg ion, and Al ion.

The specific gravity of the electrolytic solution in the fully charged lead storage battery at 20 ° C. is, for example, 1.20 or more, and may be 1.25 or more. The specific gravity of the electrolytic solution at 20 ° C. is 1.35 or less, preferably 1.32 or less.

The specific gravity of the electrolytic solution at 20 ° C. may be 1.20 or more and 1.35 or less, 1.20 or more and 1.32 or less, 1.25 or more and 1.35 or less, or 1.25 or more and 1.32 or less. ..

(others)
The lead-acid battery can be obtained by a manufacturing method including a step of accommodating a group of plates and an electrolytic solution in a cell chamber of an electric tank. Each cell of the lead-acid battery includes a group of plates and an electrolytic solution housed in each cell chamber. The electrode plate group is assembled by laminating the positive electrode plate, the negative electrode plate, and the separator so that the separator is interposed between the positive electrode plate and the negative electrode plate prior to the accommodation in the cell chamber. The positive electrode plate, the negative electrode plate, the electrolytic solution, and the separator are each prepared prior to assembling the electrode plate group. The method for manufacturing a lead-acid battery may include, if necessary, a step of forming at least one of a positive electrode plate and a negative electrode plate after a step of accommodating a group of electrode plates and an electrolytic solution in a cell chamber.

Each plate in the plate group may be one plate or two or more plates. When the electrode plate group includes two or more negative electrode plates, if at least one negative electrode plate satisfies the condition that the negative electrode electrode material contains the first surfactant in the above-mentioned content, this negative electrode plate is satisfied. The effect of suppressing the decrease in charge acceptability can be obtained, and the effect of reducing the amount of overcharged electricity can be obtained according to the number of such negative electrode plates. From the viewpoint of further suppressing the decrease in charge acceptability and ensuring a high reduction effect of the amount of overcharged electricity, 50% or more (more preferably 80% or more or 90%) of the number of negative electrode plates included in the electrode plate group. The above) is preferably a negative electrode plate that satisfies the above conditions. Among the negative electrode plates included in the electrode plate group, the ratio of the negative electrode plates satisfying the above conditions is 100% or less. All of the negative electrode plates included in the electrode plate group may satisfy the above conditions.

When the lead-acid battery has two or more cells, it is sufficient that the electrode plate group of at least a part of the cells has a negative electrode plate satisfying the above conditions. From the viewpoint of further suppressing the decrease in charge acceptability and ensuring a high reduction effect of the amount of overcharged electricity, 50% or more (more preferably 80% or more or 90% or more) of the number of cells contained in the lead storage battery. However, it is preferable to provide a group of electrode plates including a negative electrode plate that satisfies the above conditions. Among the cells contained in the lead storage battery, the ratio of the cells including the electrode plate group including the negative electrode plate satisfying the above conditions is 100% or less. It is preferable that all of the electrode plates included in the lead storage battery are provided with a negative electrode plate that satisfies the above conditions.

FIG. 1 shows the appearance of an example of a lead storage battery according to an embodiment of the present invention.
The lead-acid battery 1 includes an electric tank 12 for accommodating a plate group 11 and an electrolytic solution (not shown). The inside of the electric tank 12 is partitioned into a plurality of cell chambers 14 by a partition wall 13. One electrode plate group 11 is housed in each cell chamber 14. The opening of the battery case 12 is closed by a lid 15 including a negative electrode terminal 16 and a positive electrode terminal 17. The lid 15 is provided with a liquid spout 18 for each cell chamber. At the time of refilling water, the liquid spout 18 is removed and the refilling liquid is replenished. The liquid spout 18 may have a function of discharging the gas generated in the cell chamber 14 to the outside of the battery.

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 bag-shaped separator 4 accommodating the negative electrode plate 2 is shown, but the form of the separator is not particularly limited. In the cell chamber 14 located at one end of the battery case 12, the negative electrode shelf portion 6 for connecting the plurality of negative electrode plates 2 in parallel is connected to the through connection body 8, and the positive electrode shelf portion for connecting the plurality of positive electrode plates 3 in parallel is connected. 5 is connected to the positive electrode column 7. The positive electrode column 7 is connected to the positive electrode terminal 17 outside the lid 15. In the cell chamber 14 located at the other end of the battery case 12, the negative electrode column 9 is connected to the negative electrode shelf portion 6, and the penetration connecting body 8 is connected to the positive electrode shelf portion 5. The negative electrode column 9 is connected to the negative electrode terminal 16 outside the lid 15. Each through-connecting body 8 passes through a through-hole provided in the partition wall 13 and connects the electrode plates 11 of the adjacent cell chambers 14 in series.

The positive electrode shelf 5 is formed by welding the ears provided on the upper part of each positive electrode plate 3 by a cast-on-strap method or a burning method. The negative electrode shelf portion 6 is also formed by welding the selvage portions provided on the upper portions of the negative electrode plates 2 as in the case of the positive electrode shelf portion 5.

The lid 15 of the lead storage battery has a single structure (single lid), but is not limited to the case shown in the illustrated example. The lid 15 may have, for example, a double structure including an inner lid and an outer lid (or upper lid). The lid having a double structure may be provided with a reflux structure between the inner lid and the outer lid for returning the electrolytic solution to the inside of the battery (inside the inner lid) from the reflux port provided in the inner lid.

In the present specification, each of the overcharged electricity amount and the charge acceptability is evaluated by the following procedure. The rated voltage of the test battery used for the evaluation is 2V, and the rated 5-hour rate capacity is 32Ah.

(2) Evaluation (a) Overcharged electricity amount The overcharged electricity amount is evaluated by the following procedure using the above test battery in a fully charged state. Specifically, the fully charged test battery is constantly charged at a voltage of 2.4 V / cell for 168 hours in a water tank having a temperature of 60 ± 3 ° C. By multiplying the charging current (A) at the time of constant voltage charging by the charging time (h), the integrated value (Ah) of the overcharged electricity amount can be obtained. The amount of overcharged electricity is evaluated based on this integrated value.

(B) Charge acceptability Measure the amount of electricity at the 10th second using a fully charged test battery. Specifically, the test battery is discharged at 6.4 A for 30 minutes and left for 16 hours. After that, the upper limit of the current is set to 200 A, the test battery is charged at a constant current and constant voltage at 2.42 V / cell, and the integrated electric energy for 10 seconds (the electric energy at the 10th second) at this time is measured. Both operations are performed in a water tank at 25 ° C ± 2 ° C. The integrated amount of electricity for 10 seconds is used as an index for evaluating charge acceptability.

The lead-acid batteries according to one aspect of the present invention are summarized below.

(1) Lead-acid battery
The lead-acid battery comprises at least one cell comprising a group of plates and an electrolytic solution.
The electrode plate group includes a positive electrode plate, a negative electrode plate, and a separator interposed between the negative electrode plate and the positive electrode plate.
The negative electrode plate comprises a negative electrode material and is provided with a negative electrode material.
The negative electrode material contains a cationic surfactant (first surfactant) having one or more hydrophobic groups and hydrophilic groups.
At least one of the hydrophobic groups is a long-chain aliphatic hydrocarbon group having 8 or more carbon atoms (first hydrophobic group).
A lead-acid battery in which the content of the cationic surfactant (first surfactant) in the negative electrode material is 10 ppm or more on a mass basis.

(2) In the above (1), the number of the hydrophobic groups in the first surfactant may be one or more, two or more, or three or more.

(3) The lead-acid battery according to claim 1 or 2, wherein in the above (1) or (2), the first surfactant contains a quaternary ammonium salt.

(4) In the above (3), the number of the first hydrophobic groups contained in one molecule of the quaternary ammonium salt may be 4 or less, 3 or less, or 2 or less.

(5) In any one of the above (1) to (4), the number of carbon atoms of the first hydrophobic group may be 10 or more, 14 or more, 16 or more, or 18 or more.

(6) In any one of the above (1) to (5), the carbon number of the first hydrophobic group may be 30 or less, 26 or less, 24 or less, or 22 or less.

(7) In any one of the above (1) to (6), at least one of the hydrophobic groups is a long-chain aliphatic hydrocarbon group having 16 or more carbon atoms as the first hydrophobic group. There may be.

(8) In any one of the above (1) to (7), the first surfactant may have a second hydrophobic group other than the first hydrophobic group.

(9) In any one of the above (1) to (8), the content of the first surfactant in the negative electrode electrode material is 10 ppm or more, 50 ppm or more, 100 ppm or more, 150 ppm or more on a mass basis. , 250 ppm or more, or 300 ppm or more.

(10) In any one of the above (1) to (9), the content of the first surfactant in the negative electrode electrode material is 1000 ppm or less, 700 ppm or less, 600 ppm or less, 500 ppm or less on a mass basis. , 400 ppm or less, or 300 ppm or less.

(11) In any one of the above (1) to (10), the negative electrode electrode material may contain an organic shrinkage proofing agent.

(12) In the above (11), the negative electrode material may contain a lignin compound as the organic shrinkage proofing agent.

(13) In the above (11) or (12), the negative electrode electrode material may contain a condensate of a bis-alene compound as the organic shrinkage proofing agent.

(14) In any one of the above (11) to (13), the content of the organic shrinkage-proofing agent in the negative electrode electrode material is 0.005% by mass or more, or 0.01% by mass or more. May be good.

(15) In any one of the above (11) to (14), the content of the organic shrinkage-proofing agent in the negative electrode electrode material is 1.0% by mass or less, 0.5% by mass or less, 0.3. It may be mass% or less, or 0.25 mass% or less.

(16) In any one of the above (1) to (15), the negative electrode material may contain a carbonaceous material.

(17) In the above (16), the specific surface area of the carbonaceous material is 0.5 (m ² · g ^-1 ) or more, 1 (m ² · g ^-1 ) or more, and 20 (m ² · g ^-1 ) or more. ) Or more, 300 (m ² · g ^-1 ) or more, or 400 (m ² · g ^-1 ) or more.

(18) In the above (16) or (17), the specific surface area of the carbonaceous material is 1500 (m ² · g ^-1 ) or less, 1000 (m ² · g ^-1 ) or less, 800 (m ² · g). It may be ^-1 ) or less, 200 (m ² · g ^-1 ) or less, or 150 (m ² · g ^-1 ) or less.

(19) In any one of the above (16) to (18), the content of the carbonaceous material in the negative electrode electrode material is 0.05% by mass or more, or 0.10% by mass or more. May be good.

(20) In any one of the above (16) to (19), the content of the carbonaceous material in the negative electrode electrode material may be 5% by mass or less, or 3% by mass or less.

(21) In any one of the above (1) to (20), the negative electrode material may contain barium sulfate.

(22) In the above (21), the content of the barium sulfate in the negative electrode electrode material may be 0.05% by mass or more, or 0.10% by mass or more.

(23) In the above (21) or (22), the content of the barium sulfate in the negative electrode electrode material may be 3% by mass or less, or 2% by mass or less.

(24) In any one of the above (1) to (23), the specific gravity of the electrolytic solution at 20 ° C. in the fully charged lead-acid battery may be 1.20 or more or 1.25 or more. ..

(25) In any one of the above (1) to (24), even if the specific gravity of the electrolytic solution in the fully charged lead-acid battery at 20 ° C. is 1.35 or less, or 1.32 or less. good.

[Example]
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.

<< Lead-acid batteries E1 to E17 and C1 to C10 >>
(1) Preparation of lead-acid battery (a) Preparation of negative electrode plate Lead powder as a raw material, barium sulfate, carbon black as a carbonaceous material, a surfactant shown in the table, and an organic shrinkage proofing agent shown in the table are used. Mix with an appropriate amount of aqueous sulfuric acid to obtain a negative electrode paste. At this time, the content of the first surfactant in the negative electrode electrode material, which is obtained by the above-mentioned procedure, is the value shown in the table, the content of the organic shrinkage barrier is 0.1% by mass, and barium sulfate. Each component is mixed so that the content of carbon black is 0.4% by mass and the content of carbon black is 0.2% by mass. 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.

The following components are used as the organic shrinkage proofing agent shown in the table.
(E1) Lignin: Sodium lignin sulfonate (sulfur element content 600 μmol / g, Mw5500)
(E2) Bisphenol condensate: A formaldehyde-based condensate of a bisphenol compound having a sulfonic acid group introduced (sulfur element content: 5000 μmol / g, Mw: 9600).

(B) Preparation of positive electrode plate The lead powder as a raw material is mixed with an aqueous sulfuric acid solution to obtain a positive electrode paste. The positive 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 positive electrode plate.

(C) Preparation of test battery The test battery has a rated voltage of 2V and a rated 5-hour rate capacity of 32Ah. The electrode plate group of the test battery is composed of seven positive electrode plates and seven negative electrode plates. The negative electrode plate is housed in a bag-shaped separator formed of a microporous polyethylene film, and is alternately laminated with the positive electrode plate to form a group of electrode plates. A group of electrode plates is housed in a polypropylene electric tank together with an electrolytic solution (sulfuric acid aqueous solution) and chemically formed in the electric tank to produce a liquid-type lead-acid battery. The specific gravity of the electrolytic solution in a fully charged lead-acid battery at 20 ° C. is 1.28.

(2) Evaluation (a) Overcharged electricity amount For the lead-acid battery, the integrated value of the overcharged electricity amount is obtained by the above-mentioned procedure. The overcharged electricity amount of each lead storage battery is evaluated by the ratio when the integrated value of the overcharged electricity amount of the lead storage battery C1 is 100.

(B) Charge acceptability For the lead-acid battery, the integrated electric energy for 10 seconds is measured by the procedure described above. The charge acceptability of each lead-acid battery is evaluated by the ratio when the integrated electric energy of the lead-acid battery C1 is 100.

The results are shown in Tables 1 to 3. The table also shows the value of the ratio (A) / (B) of the charge acceptability evaluation result (A) to the overcharge electricity amount evaluation result (B). When the ratio (A) / (B) is 1 or less, it indicates that the balance between high charge acceptability and low overcharge electricity amount is excellent. E1 to E17 are examples, and C1 to C10 are comparative examples. Table 3 also shows the specific surface area of the carbonaceous material contained in the negative electrode material.

As shown in Table 1, when the negative electrode material contains a second surfactant other than the first surfactant, tetramethylammonium chloride or tetrapropylammonium chloride, as compared with the case where the surfactant is not contained. Although the charge acceptability is improved, the amount of overcharged electricity cannot be reduced (comparison between C1 and C2 to C7). However, when the negative electrode material contains the first surfactant, the amount of overcharged electricity can be reduced while ensuring relatively high charge acceptability (E1 to E12).

From the viewpoint of further enhancing the effect of reducing the amount of overcharged electricity, it is preferable that the negative electrode material contains a quaternary ammonium salt type first surfactant. From the same viewpoint, the negative electrode material preferably contains at least a first surfactant having a long-chain aliphatic hydrocarbon group having 14 or more or 16 or more carbon atoms as the first hydrophobic group. When the negative electrode electrode material contains a first surfactant having a long-chain aliphatic hydrocarbon group having 18 or more carbon atoms as the first hydrophobic group, or having two or more first hydrophobic groups. 1 It is also preferable to contain a surfactant.

As shown in Table 2, even when a lignin compound is used as the organic shrinkage proofing agent, high charge acceptability can be ensured while keeping the amount of overcharge electricity low. When a condensate of a bis-alene compound is used as the organic shrinkage proofing agent, higher charge acceptability can be ensured as compared with the case where a lignin compound is used.

As shown in Table 3, when the negative electrode material does not contain the first surfactant, as the specific surface area of the carbonaceous material increases, the charge acceptability increases, but the amount of overcharged electricity tends to increase. There is. When the negative electrode material contains the first surfactant, the amount of overcharged electricity can be reduced even if the specific surface area of the carbonaceous material is large, while ensuring relatively high charge acceptability.

The lead-acid battery according to one aspect of the present invention is suitable for use in an idling stop vehicle as, for example, a lead-acid battery for IS that is charged and discharged under PSOC conditions. Further, the lead-acid battery can be suitably used, for example, as a power source for starting a vehicle (automobile, motorcycle, etc.) and an industrial power storage device (for example, a power source for an electric vehicle (forklift, etc.)). It should be noted that these are merely examples, and the use of the lead storage battery is not limited to these.

1: Lead-acid battery 2: Negative electrode plate 3: Positive electrode plate 4: Separator 5: Positive electrode shelf part 6: Negative electrode shelf part 7: Positive electrode pillar 8: Through connection body 9: Negative electrode pillar 11: Electrode plate group 12: Electric tank 13: Bulk partition 14: Cell chamber 15: Lid 16: Negative electrode terminal 17: Positive electrode terminal 18: Liquid spout

Claims (7)

It ’s a lead-acid battery.
The lead-acid battery comprises at least one cell comprising a group of plates and an electrolytic solution.
The electrode plate group includes a positive electrode plate, a negative electrode plate, and a separator interposed between the negative electrode plate and the positive electrode plate.
The negative electrode plate comprises a negative electrode material and is provided with a negative electrode material.
The negative electrode material contains a cationic surfactant having one or more hydrophobic groups and hydrophilic groups.
At least one of the hydrophobic groups is a long-chain aliphatic hydrocarbon group having 8 or more carbon atoms.
A lead-acid battery in which the content of the cationic surfactant in the negative electrode material is 10 ppm or more on a mass basis. The lead-acid battery according to claim 1, wherein at least one of the hydrophobic groups is a long-chain aliphatic hydrocarbon group having 16 or more carbon atoms. The lead-acid battery according to claim 1 or 2, wherein the cationic surfactant contains a quaternary ammonium salt. The lead-acid battery according to any one of claims 1 to 3, wherein the long-chain aliphatic hydrocarbon group has 26 or less carbon atoms. The lead-acid battery according to any one of claims 1 to 4, wherein the content of the cationic surfactant in the negative electrode material is 50 ppm or more on a mass basis. The lead-acid battery according to any one of claims 1 to 5, wherein the content of the cationic surfactant in the negative electrode material is 600 ppm or less on a mass basis. The lead-acid battery according to any one of claims 1 to 6, wherein the negative electrode material contains a condensate of a bis-alene compound.

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