WO2018105005A1

WO2018105005A1 - Lead storage battery

Info

Publication number: WO2018105005A1
Application number: PCT/JP2016/086066
Authority: WO
Inventors: 耕二木暮; 山下　剛; 耕介原
Original assignee: 日立化成株式会社
Priority date: 2016-12-05
Filing date: 2016-12-05
Publication date: 2018-06-14
Also published as: JPWO2018105005A1

Abstract

This lead storage battery is provided with a positive plate 12 and a negative plate 13, the negative plate 13 has a current collector, and a negative electrode material held by the current collector, and when the charging status is 0 %, the resistivity of the negative electrode material is 1.02 Ω/cm or lower.

Description

Lead acid battery

The present invention relates to a lead storage battery.

Lead-acid batteries are inexpensive and highly reliable, so they are widely used as power sources for starting automobiles, power sources for electric vehicles (golf carts, etc.), power supplies for industrial equipment (uninterruptible power supplies, etc.), etc. in use.

In recent years, various measures for improving fuel efficiency have been studied for automobiles in order to prevent air pollution or global warming. For example, micro-hybrid vehicles (micro-hybrid system vehicles) are being studied as vehicles that have taken measures to improve fuel efficiency. As the micro hybrid vehicle, for example, an idling stop vehicle (hereinafter referred to as “ISS vehicle”) that reduces the operating time of the engine, and a power generation control vehicle that reduces the power generation of an alternator (generator) by the power of the engine are considered. ing.

In lead acid batteries installed in ISS cars, the usage method is basically different from conventional lead acid batteries. Conventional lead-acid batteries have been used in a fully charged state by charging from an alternator after passing a large current only at the start.

In ISS cars, the number of engine starts increases, so the large current discharge of the lead storage battery is repeated. In addition, in micro hybrid vehicles such as ISS vehicles and power generation control vehicles, the amount of power generated by the alternator is reduced, and lead storage batteries are charged intermittently, so that charging is insufficient. The lead-acid battery that is used as described above is used in a partially charged state called PSOC (Partial State Of Charge).

In recent years, in Europe, the chargeability of lead-acid batteries during charge / discharge cycles is regarded as important as the chargeability according to the control of micro hybrid vehicles, and this form of DCA (Dynamic Charge Acceptance) evaluation is the standard. It is becoming.

A lead storage battery required for an ISS vehicle needs to have the following characteristics.
1) High-speed charging performance that can immediately charge the power consumed by the lead-acid battery and maintain the specified PSOC state, and the charge acceptance required to receive the brake regenerative energy from the output current from the alternator and store it in the battery 2) High durability with sufficient life under PSOC usage environment

Regarding 1) above, the output current of the alternator of the ISS car has performance exceeding the charge acceptability of the conventional lead-acid battery. Ideally, the lead-acid battery mounted on the ISS vehicle has a characteristic that the output current of the alternator can be sufficiently received by the battery.

Regarding the above 2), when the lead storage battery is used under PSOC, it tends to fall into an early life more easily than when it is used in a fully charged state. The following reason is presumed as the reason why the life is shortened when used under PSOC.

When lead-acid batteries are used without being fully charged and insufficiently charged, there is a difference in the concentration of dilute sulfuric acid (electrolyte) between the top and bottom of the electrodes (electrode plates, etc.) in the battery. The resulting stratification phenomenon occurs. This occurs because sulfate ions generated from the upper part of the electrode plate during the charging reaction fall to the lower part. Moreover, when complete charge is performed, the electrolyte solution is stirred by gas generation (gassing) at the end of the charge. However, since such gassing does not occur in partial charging, the upper and lower portions of the electrolytic solution are not sufficiently stirred, resulting in uneven concentration and further stratification. In this case, the concentration of dilute sulfuric acid in the lower part of the electrode is increased, and a lead sulfate coarsening phenomenon called sulfation occurs in the negative electrode (eg, negative electrode plate) during discharge. Sulfation is a phenomenon in which lead sulfate, which is a discharge product, is unlikely to return to a charged state (metal lead, which is a charge product). Therefore, when sulfation occurs, the reactivity of the lower part of the electrode decreases, and only the upper part of the electrode reacts intensively. As a result, deterioration such as weakening of the connection between the active materials progresses in the upper part of the electrode, and the active material is peeled off from the current collector, leading to an early life.

In this case, in order to extend the life of the lead-acid battery, the charge acceptability is improved to prevent repeated charging / discharging in a state where charging is excessively insufficient, and lead sulfate becomes coarse due to repeated charging / discharging. It is necessary to suppress that. On the other hand, in order to improve the charge acceptability of the lead storage battery,

Patent Documents

1 and 2 below disclose the use of a negative electrode active material and a condensate of bisphenols, aminobenzenesulfonic acid and formaldehyde. .

JP 2006-196191 A International Publication No. 2016/031772

For lead-acid batteries, it is required to further improve the charge acceptability. For example, in order to further improve fuel efficiency accompanying the advancement of automobile systems, lead-acid batteries were used under PSOC for automobile lead-acid batteries. There is a need to further improve the charge acceptability.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a lead special battery capable of obtaining excellent charge acceptability.

As a result of intensive studies, the present inventors have found that the above problem can be solved when the resistivity of the negative electrode material is 0% when the state of charge is 0%.

That is, the lead storage battery according to the present invention includes a positive electrode and a negative electrode, and the negative electrode includes a current collector and a negative electrode material held by the current collector, and the state of charge is 0%. The resistivity of the negative electrode material is 1.02 Ω / cm or less.

According to the lead storage battery of the present invention, it is possible to obtain excellent charge acceptability, and in particular, it is possible to obtain excellent charge acceptability under PSOC.

Further, as a result of intensive studies by the present inventors, sufficient cycle life characteristics under PSOC (hereinafter referred to as “cycle characteristics”) cannot be obtained when the negative electrode for a lead storage battery described in Patent Document 1 is used. It became clear. On the other hand, according to the lead storage battery according to the present invention, it is possible to obtain excellent charge acceptability and cycle characteristics, and in particular, it is possible to obtain excellent charge acceptability and cycle characteristics under PSOC. Furthermore, according to the lead storage battery according to the present invention, it is possible to achieve both excellent charge acceptability and cycle characteristics and other excellent battery characteristics (such as discharge characteristics).

The negative electrode material preferably contains carbon black. The average primary particle size of the carbon black is preferably 50 nm or less. The carbon black content is preferably 0.05 to 2% by mass based on the total mass of the negative electrode material.

The negative electrode material preferably contains a resin having at least one selected from the group consisting of a sulfone group and a sulfonate group. The resin is selected from the group consisting of bisphenol compounds, at least one selected from the group consisting of aminoalkyl sulfonic acids, aminoalkyl sulfonic acid derivatives, aminoaryl sulfonic acids and aminoaryl sulfonic acid derivatives, and formaldehyde and formaldehyde derivatives. It is preferable to include a bisphenol-based resin having a structural unit derived from the reaction of at least one, and at least one selected from the group consisting of a bisphenol-based compound, aminobenzenesulfonic acid and an aminobenzenesulfonic acid derivative, formaldehyde and formaldehyde It is more preferable to include a bisphenol-based resin having a structural unit derived from the reaction with at least one selected from the group consisting of derivatives.

According to the present invention, excellent charge acceptability can be obtained. In particular, according to the present invention, excellent charge acceptability under PSOC can be obtained. In addition, according to the present invention, it is possible to achieve both excellent charge acceptability and cycle characteristics and other excellent battery characteristics (such as discharge characteristics).

According to the present invention, a lead storage battery that can be satisfactorily satisfied can be provided as a lead storage battery used in an ISS vehicle used in a harsh environment. ADVANTAGE OF THE INVENTION According to this invention, the fuel consumption improvement effect can be acquired by improving charge acceptance in the lead acid battery of an ISS car.

It is a perspective view which shows an example of a lead acid battery. It is a perspective view which shows a part of internal structure of the lead acid battery shown in FIG. It is a perspective view which shows an example of an electrode group. It is drawing for demonstrating the measuring method of the resistance value of the negative electrode material in an Example.

Hereinafter, embodiments of the present invention will be described in detail.

In this specification, a numerical range indicated by using “to” indicates a range including the numerical values described before and after “to” as the minimum value and the maximum value, respectively. In the numerical ranges described stepwise in this specification, the upper limit value or the lower limit value of a numerical range in a certain step may be replaced with the upper limit value or the lower limit value of a numerical range in another step. In the numerical range described in this specification, the upper limit value or the lower limit value of the numerical range may be replaced with the values shown in the examples. “A or B” only needs to include either A or B, and may include both. The materials exemplified in the present specification can be used singly or in combination of two or more unless otherwise specified. In the present specification, the content of each component in the composition is the total amount of the plurality of substances present in the composition unless there is a specific notice when there are a plurality of substances corresponding to each component in the composition. Means.

<Lead battery>
The lead storage battery according to the present embodiment includes an electrode, an electrolytic solution (such as sulfuric acid), and a separator. Examples of the lead storage battery according to this embodiment include a liquid lead storage battery, a control valve type lead storage battery, and the like, and a liquid lead storage battery is preferable.

The electrode has a current collector and an electrode material held by the current collector. When the electrode is not formed, the electrode includes, for example, an electrode material (electrode layer, active material layer) containing a raw material for the electrode active material, and a current collector that holds the electrode material. The electrode after the formation includes, for example, an electrode material (electrode layer, active material layer) containing an electrode active material and the like, and a current collector that holds the electrode material.

The lead storage battery according to the present embodiment includes a positive electrode (positive electrode plate or the like) and a negative electrode (negative electrode plate or the like) as electrodes. The positive electrode includes a current collector and a positive electrode material held by the current collector. The negative electrode includes a current collector and a negative electrode material held by the current collector. The lead storage battery according to the present embodiment includes, for example, an electrode after chemical conversion.

FIG. 1 is a perspective view showing an example of a lead storage battery. A lead storage battery 1 shown in FIG. 1 is a liquid lead storage battery. FIG. 2 is a perspective view showing a part of the internal structure of the lead storage battery 1. The lead storage battery 1 includes a battery case 2 in which an upper surface is opened and a plurality of electrode plate groups 11 are stored, and a lid 3 that closes the opening of the battery case 2. The lid 3 includes, for example, a positive electrode terminal 4, a negative electrode terminal 5, and a liquid port plug 6 that closes a liquid injection port provided in the lid 3. The battery case 2 contains an electrolyte (not shown).

The electrode plate group includes a separator and a positive electrode plate and a negative electrode plate that are alternately stacked via the separator. FIG. 3 is a perspective view showing an example of the electrode plate group. 2 and 3, the electrode plate group 11 includes, for example, a positive electrode plate 12, a negative electrode plate 13, a bag-like separator 14, a positive electrode side strap 15, a negative electrode side strap 16, and an inter-cell connection. A portion 17 and a pole column 18 are provided. On the upper peripheral edge of the positive electrode plate 12 and the negative electrode plate 13, a current collector 22 and a current collector 32 called ears are provided.

In the lead-acid battery according to the present embodiment, the resistivity of the negative electrode material when the state of charge (SOC: State of charge) is 0% (when the rated capacity is discharged) is 1.02 Ω / cm or less. Thereby, it is possible to obtain excellent charge acceptability, cycle characteristics, and discharge characteristics. The reason why such an effect is obtained is not clear, but the present inventors presume as follows. That is, the negative electrode of the lead storage battery contains spongy lead during charging, and discharge causes lead sulfate, which is a crystalline nonconductor, to be generated at the negative electrode. As the ratio of lead sulfate to spongy lead increases, the electrode potential of the negative electrode increases and the battery voltage decreases. At the time of complete discharge, since the ratio of lead sulfate in the active material increases, the resistivity of the negative electrode material increases and it becomes difficult to be charged. In this case, it is presumed that when the state of charge is 0% (during complete discharge), the negative electrode material has a resistivity equal to or lower than the specific value, so that charging becomes easy and excellent battery characteristics can be obtained.

The resistivity of the negative electrode material when the state of charge is 0% is preferably 1.01 Ω / cm or less, more preferably 1.00 Ω / cm or less, from the viewpoint of improving charge acceptance, discharge characteristics, and cycle characteristics in a well-balanced manner. Preferably, less than 1.00 Ω / cm is more preferable, 0.95 Ω / cm or less is particularly preferable, 0.85 Ω / cm or less is very preferable, 0.70 Ω / cm or less is very preferable, and 0.60 Ω / cm or less is preferable. Even more preferred. The resistivity of the negative electrode material can be adjusted by the content of the constituent components of the negative electrode material, the particle diameter, and the like.

The resistivity (Ω / cm) of the negative electrode material can be calculated as follows, for example. First, the rated capacity is discharged at a rate of 5 hours to obtain a negative electrode material having a charged state of 0%. Next, the terminal of a two-terminal measurement method digital multimeter (for example, product name: TY720, manufactured by Yokogawa Meter & Instruments Co., Ltd.) is measured at the measurement position A at the corner on the ear side of the negative electrode and at the negative electrode. A resistance value R (Ω) between the measurement position A and the measurement position B is measured as a resistance value of the negative electrode, installed at the measurement position B located at the corner of the diagonal position of the position A. As the measurement positions A and B, for example, positions at a distance of 10% from both ends of the longest diameter (diagonal line or the like) of the negative electrode material can be mentioned. Subsequently, a value obtained by dividing the resistance value R by the distance (cm) between the measurement position A and the measurement position B is obtained as the negative electrode resistivity R1 (Ω / cm). Next, after removing the negative electrode material from the negative electrode, the resistance value of the negative electrode current collector is measured in the same manner as described above to obtain the resistivity R2 (Ω / cm) of the negative electrode current collector. Thereafter, a value (R1-R2) obtained by subtracting the resistivity R2 (Ω / cm) of the negative electrode current collector from the resistivity R1 (Ω / cm) of the negative electrode is obtained as the resistivity (Ω / cm) of the negative electrode material.

(Negative electrode material)
The negative electrode material contains, for example, (A) a negative electrode active material or a raw material thereof (hereinafter sometimes referred to as “component (A)”). Examples of the negative electrode active material include spongy lead. The raw material for the negative electrode active material is composed of, for example, basic lead sulfate, metal lead, and a lower oxide.

The negative electrode material can contain an additive. As an additive, a resin having at least one selected from the group consisting of barium sulfate, carbon materials (excluding carbon fibers), reinforcing short fibers, sulfone groups (sulfonic acid groups, sulfo groups) and sulfonate groups (hereinafter referred to as “additives”) For example, “resin having a sulfone group and / or a sulfonate group”). Examples of the carbon material include carbon black and graphite. Examples of carbon black include furnace black (oil furnace black, etc.), channel black, acetylene black, thermal black, ketjen black and the like. As carbon black, amorphous carbon black can be used. Examples of the reinforcing short fibers include acrylic fibers, polyethylene fibers, polypropylene fibers, polyethylene terephthalate fibers, and carbon fibers.

The negative electrode material preferably contains (B) carbon black (hereinafter, sometimes referred to as “component (B)”) from the viewpoint of obtaining further excellent charge acceptability, cycle characteristics, and discharge characteristics. Since the negative electrode material contains conductive carbon black, it becomes easier to charge by reducing the electrical resistance of the active material when lead sulfate generated at the time of complete discharge is returned to metallic lead at the time of charging, so even better charging It is assumed that acceptability, cycle characteristics and discharge characteristics are obtained.

The average primary particle size of the component (B) (the average primary particle size of the component (B) contained in the negative electrode material) is preferably 50 nm or less from the viewpoint of further improving cycle characteristics, discharge characteristics, and charge acceptability. 40 nm or less is more preferable, and 30 nm or less is still more preferable. The average primary particle diameter of the component (B) is preferably 20 nm or more from the viewpoint of easy handling during production and excellent dispersibility in the negative electrode material.

The average primary particle diameter of the component (B) is, for example, in the image of the scanning electron micrograph in the range of 100 μm in length × 100 μm in the center of the substrate after depositing the particles of the component (B) on the substrate. The value of the long side length (maximum primary particle diameter) of all particles can be obtained as a numerical value obtained by arithmetic averaging. When the average primary particle size is small (for example, when the average primary particle size can be expected to be 0.1 μm or less), all the particles in the scanning electron micrograph image in the range of 1 μm in length × 1 μm in width. Can be obtained as a numerical value obtained by arithmetically averaging the long side length values of. In addition, as a method for automatically obtaining the average primary particle size, image analysis software for two-dimensional images (manufactured by Sumitomo Metal Technology Co., Ltd., particle analysis Ver3.5) can be used.

In the case of using the component (B), the content of the component (B) is 0.01% by mass or more based on the total mass of the negative electrode material from the viewpoint of improving charge acceptance, discharge characteristics, and cycle characteristics in a balanced manner. Preferably, 0.05 mass% or more is more preferable, 0.1 mass% or more is further more preferable, and 0.2 mass% or more is particularly preferable. The content of the component (B) is preferably 2% by mass or less, based on the total mass of the negative electrode material, from the viewpoint of securing sufficient strength of the electrode material and further excellent in charge acceptance. More preferably, it is more preferably 1% by mass or less, and particularly preferably 0.6% by mass or less. The content of the component (B) is preferably 0.5% by mass or less, more preferably 0.4% by mass or less, based on the total mass of the negative electrode material, from the viewpoint of further improving discharge characteristics. From these viewpoints, the content of the component (B) is preferably 0.01 to 2% by mass, more preferably 0.05 to 2% by mass, based on the total mass of the negative electrode material, and 0.1 to 1%. 9% by mass is more preferable, 0.1-1% by mass is particularly preferable, 0.1-0.6% by mass is very preferable, 0.1-0.5% by mass is very preferable, and 0.2-0 4% by mass is even more preferable.

The negative electrode material is made of (C) a resin having a sulfone group (—SO ₃ H) and / or a sulfonate group (hereinafter, “(C) It is preferable to contain “component”. Component (C) can be used as a surfactant. The reason why the negative electrode material contains the component (C) can improve the charge acceptance, discharge characteristics and cycle characteristics in a well-balanced manner is not clear, but the metal lead forming the negative electrode active material has the component (C). The present inventors presume that by strongly adsorbing, the aggregation of metallic lead is suppressed and the negative electrode material is maintained in a state with a high specific surface area.

Examples of the component (C) include bisphenol resins, naphthalenesulfonic acid resins (excluding resins corresponding to bisphenol resins), lignin sulfonic acids, lignin sulfonates, and the like. Examples of lignin sulfonate include alkali metal salts of lignin sulfonic acid. Examples of the alkali metal salt include sodium salt and potassium salt.

The component (C) preferably contains a bisphenol-based resin from the viewpoint of further improving the charge acceptance, and (c1) a bisphenol-based compound (hereinafter referred to as “(c1) component” in some cases) and (c2) amino At least one compound selected from the group consisting of alkylsulfonic acid, aminoalkylsulfonic acid derivative, aminoarylsulfonic acid and aminoarylsulfonic acid derivative (hereinafter sometimes referred to as “component (c2)”), (c3) formaldehyde and It is more preferable to include a bisphenol-based resin having a structural unit derived from the reaction of at least one compound selected from the group consisting of formaldehyde derivatives (hereinafter sometimes referred to as “component (c3)”). The bisphenol resin having a structural unit derived from the reaction of the component (c1), the component (c2) and the component (c3) can be obtained as a condensate of the component (c1), the component (c2) and the component (c3). .

[(C1) component: bisphenol compound]
The component (c1) is a compound having two hydroxyphenyl groups. Component (c1) includes 2,2-bis (4-hydroxyphenyl) propane (hereinafter referred to as “bisphenol A”), bis (4-hydroxyphenyl) methane, and 1,1-bis (4-hydroxyphenyl) ethane. 2,2-bis (4-hydroxyphenyl) hexafluoropropane, 1,1-bis (4-hydroxyphenyl) -1-phenylethane, 2,2-bis (4-hydroxyphenyl) butane, bis (4- Hydroxyphenyl) diphenylmethane, 1,1-bis (4-hydroxyphenyl) cyclohexane, 1,1-bis (4-hydroxyphenyl) -3,3,5-trimethylcyclohexane, bis (4-hydroxyphenyl) sulfone (hereinafter, "Bisphenol S"). (C1) A component can be used individually by 1 type or in combination of 2 or more types. As the component (c1), bisphenol A is preferable from the viewpoint of further excellent charge acceptance, and bisphenol S is preferable from the viewpoint of further excellent discharge characteristics.

The proportion of bisphenol A in the component (c1) is preferably 50 mol% or more, preferably 70 mol% or more, based on the total amount of the component (c1), from the viewpoint that the cycle characteristics, discharge characteristics, and charge acceptance are easily improved in a balanced manner. Is more preferable, 90 mol% or more is further preferable, and 95 mol% or more is particularly preferable. The component (c1) may be an embodiment composed of bisphenol A (an embodiment in which 100 mol% of the component (c1) is substantially bisphenol A).

((C2) component: aminoalkylsulfonic acid, aminoalkylsulfonic acid derivative, aminoarylsulfonic acid and aminoarylsulfonic acid derivative)
Examples of the aminoalkylsulfonic acid include aminomethanesulfonic acid, 2-aminoethanesulfonic acid, 3-aminopropanesulfonic acid, 2-methylaminoethanesulfonic acid and the like.

Examples of aminoalkyl sulfonic acid derivatives include compounds in which at least some of the hydrogen atoms of aminoalkyl sulfonic acid are substituted with alkyl groups (for example, alkyl groups having 1 to 5 carbon atoms), and the like. Examples include compounds in which atoms are substituted with alkali metals (for example, sodium and potassium) (for example, alkali metal salts such as sodium salt and potassium salt).

Examples of aminoarylsulfonic acid include aminobenzenesulfonic acid and aminonaphthalenesulfonic acid.

Examples of the aminobenzene sulfonic acid include 2-aminobenzene sulfonic acid (alias: alteranilic acid), 3-aminobenzene sulfonic acid (alias: metanilic acid), 4-aminobenzene sulfonic acid (alias: sulfanilic acid), and the like.

Examples of aminonaphthalenesulfonic acid include 4-amino-1-naphthalenesulfonic acid (p-form), 5-amino-1-naphthalenesulfonic acid (ana-form), 1-amino-6-naphthalenesulfonic acid (ε-form) 5-amino-2-naphthalenesulfonic acid), 6-amino-1-naphthalenesulfonic acid (ε-form), 6-amino-2-naphthalenesulfonic acid (amphi-form), 7-amino-2-naphthalenesulfone Acid, aminonaphthalene monosulfonic acid such as 8-amino-1-naphthalenesulfonic acid (peri-form), 1-amino-7-naphthalenesulfonic acid (kata-form, 8-amino-2-naphthalenesulfonic acid); 1 -Amino-3,8-naphthalenedisulfonic acid, 3-amino-2,7-naphthalenedisulfonic acid, 7-amino-1,5-naphthalenedisulfonic acid Aminonaphthalenedisulfonic acid such as sulfonic acid, 6-amino-1,3-naphthalenedisulfonic acid, 7-amino-1,3-naphthalenedisulfonic acid; 7-amino-1,3,6-naphthalenetrisulfonic acid, 8- And aminonaphthalene trisulfonic acid such as amino-1,3,6-naphthalene trisulfonic acid.

Examples of aminoarylsulfonic acid derivatives include aminobenzenesulfonic acid derivatives and aminonaphthalenesulfonic acid derivatives.

The aminobenzenesulfonic acid derivative includes a compound in which at least a part of hydrogen atoms of aminobenzenesulfonic acid is substituted with an alkyl group (for example, an alkyl group having 1 to 5 carbon atoms) or the like, hydrogen of a sulfone group of aminobenzenesulfonic acid Examples include compounds in which atoms are substituted with alkali metals (for example, sodium and potassium) (for example, alkali metal salts such as sodium salt and potassium salt). Examples of the compound in which at least a part of hydrogen atoms of aminobenzenesulfonic acid are substituted with alkyl groups include 4- (methylamino) benzenesulfonic acid, 3-methyl-4-aminobenzenesulfonic acid, and 3-amino-4-methyl. Examples thereof include benzenesulfonic acid, 4- (ethylamino) benzenesulfonic acid, 3- (ethylamino) -4-methylbenzenesulfonic acid and the like. Examples of the compound in which the hydrogen atom of the sulfone group of aminobenzenesulfonic acid is replaced with an alkali metal include sodium 2-aminobenzenesulfonate, sodium 3-aminobenzenesulfonate, sodium 4-aminobenzenesulfonate, 2-aminobenzenesulfone. Examples include potassium acid, potassium 3-aminobenzenesulfonate, and potassium 4-aminobenzenesulfonate.

Examples of the aminonaphthalenesulfonic acid derivative include compounds in which at least a part of hydrogen atoms of aminonaphthalenesulfonic acid are substituted with an alkyl group (for example, an alkyl group having 1 to 5 carbon atoms) or the like, hydrogen of the sulfone group of aminonaphthalenesulfonic acid Examples include compounds in which atoms are substituted with alkali metals (for example, sodium and potassium) (for example, alkali metal salts such as sodium salt and potassium salt).

The component (c2) is preferably at least one selected from the group consisting of aminobenzene sulfonic acid and aminobenzene sulfonic acid derivatives from the viewpoint of improving charge acceptance, discharge characteristics, and cycle characteristics in a well-balanced manner. That is, the bisphenol-based resin is derived from a reaction between a bisphenol-based compound, at least one selected from the group consisting of aminobenzenesulfonic acid and aminobenzenesulfonic acid derivatives, and at least one selected from the group consisting of formaldehyde and formaldehyde derivatives. It is preferable to include a bisphenol-based resin having a structural unit.

(C2) A component can be used individually by 1 type or in combination of 2 or more types. As the component (c2), 4-aminobenzenesulfonic acid is preferable from the viewpoint of further improving cycle characteristics and charge acceptability.

From the viewpoint of further improving the discharge characteristics, the amount of the component (c2) for obtaining the bisphenol-based resin is preferably 0.5 mol or more, more preferably 0.6 mol or more with respect to 1 mol of the component (c1). Preferably, 0.8 mol or more is more preferable, and 0.9 mol or more is particularly preferable. The amount of component (c2) is preferably 1.3 mol or less, more preferably 1.2 mol or less, and more preferably 1.2 mol or less, with respect to 1 mol of component (c1), from the viewpoint that the cycle characteristics and discharge characteristics can be further improved. More preferably, it is 1 mol or less.

((C3) component: formaldehyde and formaldehyde derivatives)
As formaldehyde, formaldehyde in formalin (for example, an aqueous solution of 37% by mass of formaldehyde) may be used. Examples of formaldehyde derivatives include paraformaldehyde, hexamethylenetetramine, and trioxane. (C3) A component can be used individually by 1 type or in combination of 2 or more types. You may use formaldehyde and a formaldehyde derivative together.

As the component (c3), a formaldehyde derivative is preferable and paraformaldehyde is more preferable from the viewpoint of easily obtaining excellent cycle characteristics. For example, paraformaldehyde has the following structure.
HO (CH ₂ O) _n1 H (I)
[In the formula (I), n1 represents an integer of 2 to 100. ]

From the viewpoint of improving the reactivity of the component (c2), the amount of the component (c3) in order to obtain the bisphenol-based resin is preferably 2 mols or more with respect to 1 mol of the component (c1). 2 mol or more is more preferable, 2.4 mol or more is further preferable, 2.6 mol or more is especially preferable, and 2.8 mol or more is very preferable. From the viewpoint of excellent solubility of the obtained bisphenol-based resin in a solvent, the amount of component (c3) in terms of formaldehyde is preferably 3.5 mol or less with respect to 1 mol of component (c1), and 3.2 mol. The following is more preferable, and 3 mol or less is still more preferable.

For example, the bisphenol-based resin preferably has at least one of a structural unit represented by the following general formula (II) and a structural unit represented by the following general formula (III).

[In the formula (II), X ² represents a divalent group, A ² represents an alkylene group having 1 to 4 carbon atoms or an arylene group, and R ²¹ , R ²³ and R ²⁴ are each independently Represents an alkali metal or hydrogen atom, R ²² represents a methylol group (—CH ₂ OH), n21 represents an integer of 1 to 150, n22 represents an integer of 1 to 3, and n23 represents 0 Or 1 is shown. Further, the hydrogen atom directly bonded to the carbon atom constituting the benzene ring may be substituted with an alkyl group having 1 to 5 carbon atoms. ]

[In Formula (III), X ³ represents a divalent group, A ³ represents an alkylene group having 1 to 4 carbon atoms or an arylene group, and R ³¹ , R ³³ and R ³⁴ are each independently selected. Represents an alkali metal or a hydrogen atom, R ³² represents a methylol group (—CH ₂ OH), n31 represents an integer of 1 to 150, n32 represents an integer of 1 to 3, and n33 represents 0 Or 1 is shown. Further, the hydrogen atom directly bonded to the carbon atom constituting the benzene ring may be substituted with an alkyl group having 1 to 5 carbon atoms. ]

The ratio of the structural unit represented by the formula (II) and the structural unit represented by the formula (III) is not particularly limited, and may vary depending on synthesis conditions and the like. As the bisphenol-based resin, a resin having only one of the structural unit represented by the formula (II) and the structural unit represented by the formula (III) may be used.

The bisphenol-based resin preferably has, for example, at least one of a structural unit represented by the following general formula (IIa) and a structural unit represented by the following general formula (IIIa).

[In Formula (IIa), X ² represents a divalent group, R ²¹ , R ²³ and R ²⁴ each independently represents an alkali metal or a hydrogen atom, and R ²² represents a methylol group (—CH ₂ OH N21 represents an integer of 1 to 150, n22 represents an integer of 1 to 3, and n23 represents 0 or 1. Further, the hydrogen atom directly bonded to the carbon atom constituting the benzene ring may be substituted with an alkyl group having 1 to 5 carbon atoms. ]

[In Formula (IIIa), X ³ represents a divalent group, R ³¹ , R ³³ and R ³⁴ each independently represents an alkali metal or a hydrogen atom, and R ³² represents a methylol group (—CH ₂ OH N31 represents an integer of 1 to 150, n32 represents an integer of 1 to 3, and n33 represents 0 or 1. Further, the hydrogen atom directly bonded to the carbon atom constituting the benzene ring may be substituted with an alkyl group having 1 to 5 carbon atoms. ]

The ratio of the structural unit represented by the formula (IIa) and the structural unit represented by the formula (IIIa) is not particularly limited, and may vary depending on synthesis conditions and the like. As the bisphenol-based resin, a resin having only one of the structural unit represented by the formula (IIa) and the structural unit represented by the formula (IIIa) may be used.

Examples of X ² and X ³ include alkylidene groups (methylidene group, ethylidene group, isopropylidene group, sec-butylidene group, etc.), cycloalkylidene groups (cyclohexylidene group, etc.), phenylalkylidene groups (diphenylmethylidene group). An organic group such as a phenylethylidene group; a sulfonyl group. X ² and X ³ are preferably an isopropylidene group (—C (CH ₃ ) ₂ —) group from the viewpoint of further excellent charge acceptance, and a sulfonyl group (—SO ₂ —) from the viewpoint of further excellent discharge characteristics. ) Is preferred. X ² and X ³ may be substituted with a halogen atom such as a fluorine atom. When X ² and X ³ are cycloalkylidene groups, the hydrocarbon ring may be substituted with an alkyl group or the like.

Examples of A ² and A ³ include alkylene groups having 1 to 4 carbon atoms such as a methylene group, an ethylene group, a propylene group, and a butylene group; and divalent arylene groups such as a phenylene group and a naphthylene group. The arylene group may be substituted with an alkyl group or the like.

^Examples of the alkali metal for R ²¹ , R ²³ , R ²⁴ , R ³¹ , R ³³ and R ³⁴ include sodium and potassium. n21 and n31 are preferably 1 to 150, and more preferably 10 to 150, from the viewpoint of further excellent cycle characteristics and the solubility of the bisphenol-based resin in a solvent. n22 and n32 are preferably 1 or 2, and more preferably 1, from the viewpoint that the cycle characteristics, the discharge characteristics, and the charge acceptability are easily improved in a balanced manner. n23 and n33 vary depending on the production conditions, but 0 is preferable from the viewpoint of excellent cycle characteristics and storage stability of the bisphenol-based resin.

The method for producing a bisphenol-based resin includes a resin production step of obtaining a bisphenol-based resin by reacting the component (c1), the component (c2) and the component (c3).

The bisphenol-based resin can be obtained, for example, by reacting the component (c1), the component (c2) and the component (c3) in a reaction solvent. The reaction solvent is preferably water (for example, ion exchange water). In order to promote the reaction, an organic solvent, a catalyst, an additive, or the like may be used.

In the resin production process, from the viewpoint of further improving the cycle characteristics of the lead storage battery, the blending amount of the component (c2) is 0.5 to 1.3 mol with respect to 1 mol of the component (c1), and (c3) An embodiment in which the amount of the component is 2 to 3.5 mol in terms of formaldehyde with respect to 1 mol of the component (c1) is preferable. Preferred blending amounts of the component (c2) and the component (c3) are the ranges described above for the blending amounts of the component (c2) and the component (c3).

The bisphenol-based resin is preferably obtained by reacting the component (c1), the component (c2) and the component (c3) under basic conditions (alkaline conditions) from the viewpoint that a sufficient amount of bisphenol-based resin can be easily obtained. In order to adjust to basic conditions, you may use a basic compound. Examples of the basic compound include sodium hydroxide, potassium hydroxide, calcium hydroxide, magnesium hydroxide, sodium carbonate and the like. A basic compound can be used individually by 1 type or in combination of 2 or more types. Among the basic compounds, at least one selected from the group consisting of sodium hydroxide and potassium hydroxide is preferable from the viewpoint of excellent reactivity.

When the reaction solution containing the component (c1), the component (c2) and the component (c3) is neutral (pH = 7) at the start of the reaction, the formation reaction of the bisphenol-based resin may not easily proceed. If the solution is acidic (pH <7), side reactions may proceed. Therefore, the pH of the reaction solution at the start of the reaction is preferably greater than 7 (alkaline) from the viewpoint of suppressing the side reaction from proceeding while the bisphenol-based resin formation reaction proceeds, and is 7.1 or more Is more preferable, and 7.2 or more is still more preferable. The pH of the reaction solution is preferably 12 or less, more preferably 10 or less, and still more preferably 9 or less, from the viewpoint of suppressing the hydrolysis of the group derived from the component (c2) in the bisphenol-based resin. The pH of the reaction solution can be measured, for example, with a twin pH meter AS-212 manufactured by Horiba, Ltd. The pH is defined as the pH at 25 ° C.

Since it is easy to adjust the pH as described above, the compounding amount of the strongly basic compound is preferably 1.01 mol or more, more preferably 1.02 mol or more, relative to 1 mol of the component (c2). 03 mol or more is more preferable. From the same viewpoint, the compounding amount of the strongly basic compound is preferably 1.1 mol or less, more preferably 1.08 mol or less, and further preferably 1.07 mol or less with respect to 1 mol of the component (c2). Examples of the strongly basic compound include sodium hydroxide and potassium hydroxide.

In the synthesis reaction of the bisphenol resin, the (c1) component, the (c2) component, and the (c3) component may react to obtain a bisphenol resin. For example, the component (c1), the component (c2), and the component (c3) may be reacted at the same time. After reacting two of the components (c1), (c2), and (c3), The reaction product obtained may be reacted with the remaining one component.

The synthesis reaction of the bisphenol-based resin is preferably performed in two steps as follows.

In the first stage reaction, for example, an aminoalkyl sulfonic acid and / or aminoaryl sulfonic acid, a solvent (such as water) and a basic compound are mixed and stirred, and then the aminoalkyl sulfonic acid and / or aminoaryl sulfonic acid is mixed. An alkali metal salt or the like is obtained by replacing the hydrogen atom of the sulfone group in the acid with an alkali metal or the like. Thereby, it becomes easy to suppress a side reaction in the below-mentioned condensation reaction. The temperature of the reaction system is preferably 0 ° C. or higher, more preferably 25 ° C. or higher, from the viewpoint of excellent solubility of aminoalkylsulfonic acid and / or aminoarylsulfonic acid in a solvent (such as water). The temperature of the reaction system is preferably 80 ° C. or less, more preferably 70 ° C. or less, and still more preferably 65 ° C. or less from the viewpoint of suppressing side reactions. The reaction time is, for example, 5 to 30 minutes.

In the second stage reaction, for example, the components (c1) and (c3) are added to the reaction product obtained in the first stage and subjected to a condensation reaction to obtain a bisphenol-based resin. The temperature of the reaction system is preferably 75 ° C. or higher, more preferably 85 ° C. or higher, and still more preferably 87 ° C. or higher, from the viewpoint of excellent reactivity of the components (c1), (c2) and (c3). The temperature of the reaction system is preferably 100 ° C. or lower, more preferably 95 ° C. or lower, and still more preferably 93 ° C. or lower, from the viewpoint of suppressing side reactions. The reaction time is, for example, 5 to 20 hours.

In the present embodiment, a reaction product (for example, a reaction solution) obtained by the method for producing the bisphenol-based resin may be used as it is for production of an electrode to be described later, or obtained by drying the reaction product by a spray drying method or the like. The resulting powder may be used for the production of electrodes.

The weight average molecular weight of the bisphenol-based resin is preferably 20000 or more, more preferably 30000 or more, and 40000 from the viewpoint that the cycle characteristics are easily improved by suppressing the bisphenol-based resin from eluting from the electrode to the electrolyte in the lead storage battery. The above is more preferable, 50000 or more is particularly preferable, 55000 or more is very preferable, and 58000 or more is very preferable. The weight average molecular weight of the bisphenol-based resin is preferably 70,000 or less, preferably 65,000 or less, from the viewpoint of easily improving cycle characteristics by suppressing the decrease in the dispersibility due to the decrease in the adsorptivity of the bisphenol-based resin with respect to the electrode active material. Is more preferably 62,000 or less, particularly preferably 60000 or less.

The weight average molecular weight of the bisphenol-based resin can be measured, for example, by gel permeation chromatography (hereinafter referred to as “GPC”) under the following conditions.
(GPC conditions)
Apparatus: High performance liquid chromatograph LC-2200 Plus (manufactured by JASCO Corporation)
Pump: PU-2080
Differential refractometer: RI-2031
Detector: UV-visible spectrophotometer UV-2075 (λ: 254 nm)
Column oven: CO-2065
Column: TSKgel SuperAW (4000), TSKgel SuperAW (3000), TSKgel SuperAW (2500) (manufactured by Tosoh Corporation)
Column temperature: 40 ° C
Eluent: methanol solution containing LiBr (10 mM) and triethylamine (200 mM) Flow rate: 0.6 mL / min Molecular weight standard sample: Polyethylene glycol (molecular weight: 1.10 × 10 ⁶ , 5.80 × 10 ⁵ , 2.55 × 10 ⁵ , 1.46 × 10 ⁵ , 1.01 × 10 ⁵ , 4.49 × 10 ⁴ , 2.70 × 10 ⁴ , 2.10 × 10 ⁴ ; manufactured by Tosoh Corporation), diethylene glycol (molecular weight: 1 .06 × 10 ² ; manufactured by Kishida Chemical Co., Ltd.), dibutylhydroxytoluene (molecular weight: 2.20 × 10 ² ; manufactured by Kishida Chemical Co., Ltd.)

The naphthalene sulfonic acid resin is a resin having a structural unit derived from naphthalene sulfonic acid (excluding a resin corresponding to a bisphenol resin), for example, a resin having a sulfonic acid group-containing naphthylene structure.

The naphthalene sulfonic acid resin can be obtained by reacting naphthalene sulfonic acid and a compound that can be polymerized with naphthalene sulfonic acid. For example, the naphthalene sulfonic acid resin can be obtained from the group consisting of a naphthalene sulfonic acid compound, formaldehyde, and a formaldehyde derivative. It can be obtained by reacting with at least one selected. The naphthalene sulfonic acid resin preferably has a structural unit represented by the following formula (IV).

[In the formula (IV), R ⁴¹ represents an alkali metal or a hydrogen atom, n ⁴¹ represents an integer of 1 to 100, and n 42 represents an integer of 1 to 3. Further, the hydrogen atom directly bonded to the carbon atom constituting the benzene ring may be substituted with an alkyl group having 1 to 5 carbon atoms. ]

^Examples of the alkali metal for R ⁴¹ include sodium and potassium. When a plurality of R ⁴¹ are present, R ⁴¹ may be the same as or different from each other.

Further, as the naphthalene sulfonic acid resin, a commercially available resin can also be used. Examples of commercially available naphthalene sulfonic acid resins include vanillol HDL-100 (trade name, manufactured by Nippon Paper Industries Co., Ltd.), Demol N, Demol RN, Demol NL, Demol RNL, Demol T, Demol T-45 (above, trade names, And Kao Corporation).

The naphthalene sulfonic acid compound is a compound having a naphthalene sulfonic acid group. Examples of the naphthalene sulfonic acid compound include at least one selected from the group consisting of naphthalene sulfonic acid and naphthalene sulfonic acid derivatives. Examples of naphthalene sulfonic acid include 1-naphthalene sulfonic acid and 2-naphthalene sulfonic acid. Examples of naphthalene sulfonic acid derivatives include compounds in which some of the hydrogen atoms of naphthalene sulfonic acid are substituted with alkali metals (sodium, potassium, etc.), such as sodium 1-naphthalene sulfonate, sodium 2-naphthalene sulfonate, -Potassium naphthalene sulfonate, potassium 2-naphthalene sulfonate, etc. A naphthalenesulfonic acid type compound can be used individually by 1 type or in combination of 2 or more types.

Examples of formaldehyde and formaldehyde derivatives include the same compounds as the component (c3).

The blending amount (total amount) of formaldehyde and formaldehyde derivative for obtaining naphthalenesulfonic acid resin is, for example, about 1 to 2 mol in terms of formaldehyde with respect to 1 mol of naphthalenesulfonic acid compound. The naphthalene sulfonic acid resin can be obtained under the same synthesis conditions as the bisphenol resin.

The weight average molecular weight of the naphthalene sulfonic acid resin is preferably 1000 or more, more preferably 3000 or more, still more preferably 4000 or more, and particularly preferably 5000 or more, from the viewpoint of easy improvement of the cycle characteristics of the lead storage battery. The weight average molecular weight of the naphthalene sulfonic acid resin is preferably 20000 or less, more preferably 15000 or less, and still more preferably 10,000 or less, from the viewpoint of easy improvement of cycle characteristics. The weight average molecular weight of the naphthalene sulfonic acid resin can be measured in the same manner as the weight average molecular weight of the bisphenol resin, for example.

The weight average molecular weight of lignin sulfonic acid or lignin sulfonate is 3000 from the viewpoint that the lignin sulfonic acid or lignin sulfonate is prevented from eluting from the electrode to the electrolyte in lead-acid batteries and further excellent cycle characteristics are obtained. The above is preferable, 7000 or more is more preferable, and 8000 or more is still more preferable. From the viewpoint of excellent dispersibility of the electrode active material, the weight average molecular weight of lignin sulfonic acid or lignin sulfonate is preferably 70000 or less, more preferably 50000 or less, further preferably 40000 or less, particularly preferably 30000 or less, and 20000 or less. Is very preferred. From these viewpoints, the weight average molecular weight of lignin sulfonic acid or lignin sulfonate is preferably 3000 to 70000, more preferably 3000 to 50000, still more preferably 3000 to 40000, particularly preferably 7000 to 30000, and 8000 to 20000. Highly preferred. The weight average molecular weight of lignin sulfonic acid or lignin sulfonate can be measured by the same method as the weight average molecular weight of bisphenol-based resin.

When the component (C) is used, the content of the component (C) is 0.01% by mass or more in terms of resin solid content, based on the total mass of the negative electrode material, from the viewpoint of further excellent cycle characteristics and discharge characteristics. Preferably, 0.05 mass% or more is more preferable, 0.07 mass% or more is further preferable, and 0.1 mass% or more is particularly preferable. The content of the component (C) is 2% by mass or less in terms of resin solids, based on the total mass of the negative electrode material, from the viewpoint of securing sufficient strength of the electrode material and the viewpoint of further excellent charge acceptance. 1 mass% or less is more preferable, 0.6 mass% or less is further more preferable, 0.5 mass% or less is especially preferable, and 0.3 mass% or less is very preferable. From these viewpoints, the content of the component (C) is preferably 0.01 to 2% by mass, more preferably 0.05 to 1% by mass in terms of resin solid content, based on the total mass of the negative electrode material. 0.05 to 0.6% by mass is further preferred, 0.07 to 0.5% by mass is particularly preferred, 0.07 to 0.3% by mass is very particularly preferred, and 0.1 to 0.3% by mass is extremely preferred. Is preferable.

In producing the electrode, a resin composition containing the component (C) (for example, a liquid resin solution at 25 ° C.) may be used. The resin composition may further contain a solvent. The resin composition may be a reaction product obtained in the resin production process, and is a composition obtained by mixing the component (C) and other components after the resin production process (for example, using the component (C) as a solvent. A resin solution obtained by dissolution, and a composition obtained by mixing the component (C) with the component (A) and the component (B) may be used. Aggregation of component (C) is suppressed in a mixture containing component (C) and other components by dissolving component (C) in a solvent (water, etc.) and then mixing with other components before the electrode is manufactured. Thus, the effect of the component (C) can be easily obtained. As a solvent, water (for example, ion-exchange water) and an organic solvent are mentioned, for example. The solvent contained in the resin composition may be a reaction solvent used to obtain the component (C) (such as a bisphenol-based resin).

The pH of the resin composition (for example, a resin solution that is liquid at 25 ° C.) is greater than 7 (alkaline) from the viewpoint of excellent solubility of the component (C) (bisphenol resin, etc.) in a solvent (water, etc.). Is preferably 7.1 or more. The pH of the resin composition is preferably 10 or less, more preferably 9 or less, and even more preferably 8.5 or less, from the viewpoint of excellent workability during electrode material paste preparation. In particular, when the composition obtained in the resin production process is used as a resin composition, the pH of the resin composition is preferably in the above range. The pH of the resin composition can be measured, for example, with a twin pH meter AS-212 manufactured by Horiba, Ltd. The pH is defined as the pH at 25 ° C.

The non-volatile content (Nonvolatile Matter content) in the resin composition containing the component (C) is preferably 10% by mass or more, more preferably 15% by mass or more from the viewpoint of further excellent solubility and battery characteristics of the component (C). 20% by mass or more is more preferable. From the same viewpoint, the non-volatile content in the resin composition containing the component (C) is preferably 50% by mass or less, more preferably 45% by mass or less, and further preferably 40% by mass or less.

The nonvolatile content can be measured, for example, by the following procedure. First, after putting a predetermined amount (for example, 2 g) of a resin composition into a container (for example, a metal petri dish such as a stainless steel petri dish), the resin composition is dried at 150 ° C. for 60 minutes using a hot air dryer. Next, after the temperature of the container returns to room temperature (for example, 25 ° C.), the residual mass is measured. Then, the nonvolatile content is calculated from the following formula.
Nonvolatile content (mass%) = [(residual mass after drying) / (mass of resin composition before drying)] × 100

(Positive electrode material)
The positive electrode material contains, for example, a positive electrode active material or a raw material thereof. The positive electrode active material preferably contains β-lead dioxide (β-PbO ₂ ), and may further contain α-lead dioxide (α-PbO ₂ ). The raw material for the positive electrode active material preferably contains tribasic lead sulfate. The positive electrode material may further contain an additive. Examples of the additive include barium sulfate, carbon material, reinforcing short fiber, and the like, and the same additive as the negative electrode material can be used.

<Method for producing lead-acid battery>
The method for manufacturing a lead storage battery according to the present embodiment includes, for example, an electrode manufacturing process for obtaining electrodes (positive electrode and negative electrode) and an assembly process for obtaining a lead storage battery by assembling constituent members including the electrodes.

In the electrode manufacturing process, for example, after filling an electrode material paste (a positive electrode material paste and a negative electrode material paste) into a current collector (for example, a cast lattice body and an expanded lattice body), aging and drying are performed to thereby form an unformed electrode. (For example, an electrode plate) is obtained. The positive electrode material paste contains, for example, a raw material (lead powder or the like) of the positive electrode active material, and may further contain other additives. The negative electrode material paste contains a raw material (lead powder or the like) of the negative electrode active material, and may further contain other additives. The negative electrode material paste may contain the component (B) and may contain the component (C) as a dispersant.

The negative electrode material paste can be obtained, for example, by the following method. First, an additive is added to the raw material (lead powder etc.) of a negative electrode active material, and a mixture is obtained by dry-mixing. Then, dilute sulfuric acid and water are added and kneaded to obtain a negative electrode material paste. When the component (B) is used as an additive, the component (B) is immersed in water, kneaded and then kneaded, and then mixed with the raw material of the negative electrode active material, thereby suppressing aggregation of the component (B). Since the wettability in the mixture is improved and the resistance component is reduced, the effect of the component (B) is easily obtained. An unformed negative electrode plate can be obtained by filling the negative electrode material paste into a current collector (casting grid, expanded grid, etc.) and then aging and drying.

In the case of using barium sulfate, the component (B) and / or the component (C) in the negative electrode material paste, the negative electrode material contains the following blending amount of barium sulfate, the component (B) and / or the component (C). It is preferable that the negative electrode material obtained by using (for example, the negative electrode material obtained by chemical conversion after aging and drying the negative electrode material paste).

The compounding amount of barium sulfate is preferably 0.3 to 2% by mass based on the total mass of the negative electrode active material (lead powder, etc.).

The blending amount of the component (B) is 0.01% by mass or more based on the total mass of the negative electrode active material (lead powder, etc.) from the viewpoint of improving the charge acceptance, discharge characteristics and cycle characteristics in a balanced manner. Preferably, 0.05 mass% or more is more preferable, 0.1 mass% or more is further more preferable, and 0.2 mass% or more is particularly preferable. The blending amount of the component (B) is 2 masses based on the total mass of the raw materials (lead powder, etc.) of the negative electrode active material from the viewpoint of ensuring sufficient strength of the electrode material and the viewpoint of further excellent charge acceptance. % Or less is preferable, 1.9% by mass or less is more preferable, 1% by mass or less is further preferable, and 0.6% by mass or less is particularly preferable. The blending amount of the component (B) is preferably 0.5% by mass or less, preferably 0.4% by mass or less, based on the total mass of the negative electrode active material (lead powder, etc.), from the viewpoint of further excellent discharge characteristics. More preferred. From these viewpoints, the blending amount of component (B) is preferably 0.01 to 2% by mass, more preferably 0.05 to 2% by mass, based on the total mass of the negative electrode active material (lead powder, etc.). Preferably, 0.1 to 1.9% by mass is more preferable, 0.1 to 1% by mass is particularly preferable, 0.1 to 0.6% by mass is extremely preferable, and 0.1 to 0.5% by mass is very preferable. 0.2 to 0.4 mass% is even more preferable. In addition, the blending amount of the carbon material (total amount of the carbon material including the component (B)) in the negative electrode material paste is 0.05 to 1.9 mass based on the total mass of the negative electrode active material (lead powder, etc.). % Is preferred.

Component (C) is blended in an amount of 0.01% by mass or more in terms of resin solids based on the total mass of the negative electrode active material (lead powder, etc.) from the viewpoint of further improving cycle characteristics and discharge characteristics. Preferably, 0.05 mass% or more is more preferable, 0.1 mass% or more is further more preferable, and 0.2 mass% or more is particularly preferable. The blending amount of the component (C) is a resin solid based on the total mass of the negative electrode active material (lead powder, etc.) from the viewpoint of ensuring sufficient strength of the electrode material and the viewpoint of further excellent charge acceptance. In terms of minutes, it is preferably 2% by mass or less, more preferably 1% by mass or less, still more preferably 0.6% by mass or less, particularly preferably 0.5% by mass or less, and extremely preferably 0.3% by mass or less. From these viewpoints, the blending amount of the component (C) is preferably 0.01 to 2% by mass in terms of resin solids based on the total mass of the negative electrode active material (lead powder, etc.), 0.05 To 1% by mass is more preferable, 0.05 to 0.6% by mass is further preferable, 0.1 to 0.5% by mass is particularly preferable, 0.1 to 0.3% by mass is extremely preferable, 0.2% Highly preferred is .about.0.3% by weight. Since component (C) tends to be decomposed by chemical conversion, the relative amounts of component (C) and other components may differ before and after chemical conversion.

The positive electrode material paste can be obtained, for example, by the following method. First, after adding a reinforcing short fiber to a raw material (lead powder or the like) of the positive electrode active material, a positive electrode material paste is obtained by adding dilute sulfuric acid and water and kneading. In producing the positive electrode material paste, red lead (Pb ₃ O ₄ ) may be added. An unformed positive electrode plate can be obtained by filling the positive electrode material paste into a current collector (casting grid, expanded grid, etc.) and then aging and drying. In the positive electrode material paste, the amount of the reinforcing short fibers is preferably 0.05 to 0.3% by mass based on the total mass of the raw material of the positive electrode active material (lead powder or the like). The type of collector, aging conditions or drying conditions are almost the same as in the case of the negative electrode.

Examples of the current collector material include a lead-calcium-tin alloy, a lead-calcium alloy, and a lead-antimony alloy. A small amount of selenium, silver, bismuth or the like can be added to these. The manufacturing method or material of the current collector for the positive electrode and the negative electrode may be the same as or different from each other.

As aging conditions, 15 to 30 hours are preferable in an atmosphere of a temperature of 45 to 65 ° C. and a humidity of 70 to 98 RH%. The drying conditions are preferably 45 to 60 ° C. and 15 to 30 hours.

In the assembly process, for example, the unformed negative electrode and the positive electrode prepared as described above are alternately stacked via separators, and the current collecting portions of the electrodes having the same polarity are connected by a strap (welding or the like) to form an electrode group. obtain. This electrode group is arranged in a battery case to produce an unformed battery. Examples of the separator include a microporous polyethylene sheet; a nonwoven fabric made of glass fiber and synthetic resin.

Next, after putting an electrolytic solution (dilute sulfuric acid, etc.) into an unformed battery, a direct current is applied to form a battery case. The lead acid battery can be obtained by adjusting the specific gravity of the electrolyte after the formation to an appropriate specific gravity. The specific gravity (converted to 20 ° C.) of the electrolytic solution (sulfuric acid or the like) before chemical conversion is preferably 1.20 to 1.26. The specific gravity (converted to 20 ° C.) of the electrolytic solution (sulfuric acid, etc.) after chemical conversion is preferably 1.26 to 1.30.

Chemical conversion conditions and specific gravity of sulfuric acid can be adjusted according to the properties of the electrode active material. The chemical conversion treatment is not limited to being performed after the assembly process, and may be performed after the aging and drying of the electrode manufacturing process (tank chemical conversion).

Hereinafter, the present invention will be specifically described by way of examples. However, the present invention is not limited to the following examples.

<Bisphenol resin>
(Production of bisphenol resin)
The following components were charged into a reaction vessel equipped with a stirrer, a reflux device and a temperature controller to obtain a first mixed solution.
Sodium hydroxide: 1.05 mol [42.0 parts by mass]
Ion-exchanged water: 44.00 mol [792.6 parts by mass]
4-aminobenzenesulfonic acid: 1.00 mol [173.2 parts by mass]

The first mixture was mixed and stirred at 25 ° C. for 30 minutes. Subsequently, the following components were charged into the first mixed liquid to obtain a second mixed liquid.
Bisphenol A: 1.00 mol [228.3 parts by mass]
Paraformaldehyde (manufactured by Mitsui Chemicals): 3.00 mol [90.9 parts by mass] (formaldehyde conversion)

A resin solution was obtained by reacting the second mixed solution (pH = 8.6) at 90 ° C. for 10 hours. The bisphenol resin contained in the resin solution was isolated by low temperature drying (60 ° C., 6 hours).

(Evaluation of resin solution and bisphenol resin)
[Measurement of nonvolatile content]
The nonvolatile content of the resin solution was measured by the following procedure. First, 2 g of the resin solution was placed in a 50φ × 15 mm container (stainless steel petri dish) and dried at 150 ° C. for 60 minutes using a hot air dryer. Next, after the temperature of the container returned to room temperature (25 ° C.), the non-volatile content was measured by measuring the residual mass. The measurement result of the nonvolatile content was 30% by mass.

[Measurement of pH]
After completion of the reaction, 500 mL of the resin solution was injected into the sensor unit of the following pH measurement device, and the pH of the resin solution was measured. The measurement result of pH was 7.8.
{Conditions for pH measurement}
pH measurement device: HORIBA, Ltd. Twin pH meter AS-212
Calibration solution: pH calibration solution manufactured by HORIBA, Ltd. (pH 4.01, pH 6.86)
Measurement temperature: 25 ° C

[Measurement of weight average molecular weight]
The weight average molecular weight of the bisphenol-based resin isolated for ¹ H-NMR spectrum measurement was measured by GPC under the following conditions. The weight average molecular weight of the bisphenol-based resin was 58100.
{GPC condition}
Apparatus: High performance liquid chromatograph LC-2200 Plus (manufactured by JASCO Corporation)
Pump: PU-2080
Differential refractometer: RI-2031
Detector: UV-visible spectrophotometer UV-2075 (λ: 254 nm)
Column oven: CO-2065
Column: TSKgel SuperAW (4000), TSKgel SuperAW (3000), TSKgel SuperAW (2500) (manufactured by Tosoh Corporation)
Column temperature: 40 ° C
Eluent: methanol solution containing LiBr (10 mM) and triethylamine (200 mM) Flow rate: 0.6 mL / min Molecular weight standard sample: Polyethylene glycol (molecular weight: 1.10 × 10 ⁶ , 5.80 × 10 ⁵ , 2.55 × 10 ⁵ , 1.46 × 10 ⁵ , 1.01 × 10 ⁵ , 4.49 × 10 ⁴ , 2.70 × 10 ⁴ , 2.10 × 10 ⁴ ; manufactured by Tosoh Corporation), diethylene glycol (molecular weight: 1 .06 × 10 ² ; manufactured by Kishida Chemical Co., Ltd.), dibutylhydroxytoluene (molecular weight: 2.20 × 10 ² ; manufactured by Kishida Chemical Co., Ltd.)

<Naphthalenesulfonic acid-based resin (naphthalenesulfonic acid polymer)>
As the naphthalene sulfonic acid resin, vanillol HDL-100 (Naphthalene sulfonic acid resin, trade name, manufactured by Nippon Paper Industries Co., Ltd., weight average molecular weight: 8000) was prepared.

<Lignin sulfonate (lignin sulfonate polymer)>
As lignin sulfonate, sodium lignin sulfonate (trade name: Vanillex N, manufactured by Nippon Paper Industries Co., Ltd., weight average molecular weight: 12000) was prepared.

<Production of lead acid battery>
Example 1
[Production of negative electrode plate]
Based on the total mass of lead powder, the resin solution of the bisphenol-based resin is 0.2% by mass in terms of solid content, oil furnace black (carbon black, manufactured by Lion Corporation, trade name: carbon ECP600JD, average primary particle size) : 20 nm) in terms of solid content and 0.6% by weight of barium sulfate were added to lead powder (average primary particle size: 1 μm) and then dry mixed. In the above operation, the oil furnace black was immersed in water and mixed with water, and then kneaded, and then the liquid containing the oil furnace black was mixed with the lead powder.

Next, dilute sulfuric acid (specific gravity 1.26 (converted at 20 ° C.)) and water were added and kneaded to prepare a negative electrode material paste. A negative electrode current collector (expanded grid, lead-calcium-tin alloy, thickness: 1.0 mm) was filled with a negative electrode material paste to obtain a negative electrode plate. The negative electrode plate was aged in an atmosphere at a temperature of 50 ° C. and a humidity of 95% for 20 hours, and then dried in an atmosphere at a temperature of 50 ° C. to obtain an unformed negative electrode plate.

[Production of positive electrode plate]
Based on the total mass of the lead powder, 0.1% by mass of reinforcing short fibers (acrylic fibers) was added to the lead powder (average particle diameter: 2 μm) and then dry mixed. Next, dilute sulfuric acid (specific gravity 1.28 (converted at 20 ° C.)) and water were added and kneaded to prepare a positive electrode material paste. A positive electrode current collector (expanded grid, lead-calcium-tin alloy) was filled with a positive electrode material paste to obtain a positive electrode plate. The positive electrode plate was aged in an atmosphere at a temperature of 50 ° C. and a humidity of 95% for 20 hours, and then dried in an atmosphere at a temperature of 50 ° C. to obtain an unformed positive electrode plate.

[Battery assembly]
After laminating 6 unformed negative plates and 5 unformed positive plates through a polyethylene separator so that unformed negative plates and unformed positive plates are alternately laminated, the same The polar current collectors were welded together with a strap to produce an electrode plate group. A 2V single cell battery (equivalent to B20 size of JIS D 5301) was assembled by inserting the electrode plate group into the battery case. After dilute sulfuric acid (specific gravity 1.26 (converted to 20 ° C.)) was poured into this battery, it was formed in a 40 ° C. water bath at an energization current of 10.0 A for 15 hours. After the chemical conversion, the lead acid battery of Example 1 was obtained by adjusting the diluted sulfuric acid to have a specific gravity of 1.28 (converted to 20 ° C.). As shown in Table 1, the content of carbon black is 0.6% by mass and the content of bisphenol-based resin (in terms of solid content) is 0.1% by mass, based on the total mass of the negative electrode material after chemical conversion. Met.

The resistivity (Ω / cm) of the negative electrode material was calculated as follows. First, the rated capacity was discharged at a rate of 5 hours to obtain a negative electrode material having a charged state of 0%. Next, the terminal of the two-terminal measurement method digital multimeter (product name: TY720, manufactured by Yokogawa Meter & Instruments Co., Ltd.) is measured at the measurement position A at the corner of the negative electrode plate on the ear side, and the measurement at the negative electrode plate Installed at the measurement position B located at the corner of the diagonal position of the position A (installed at the two corners shown in FIG. 4), the resistance between the measurement position A and the measurement position B as the resistance value of the negative electrode plate The value R (Ω) was measured. As measurement positions A and B, positions at a distance of 10% from both ends of the longest diameter (diagonal line) of the negative electrode material were used. Subsequently, a value obtained by dividing the resistance value R by the distance (cm) between the measurement position A and the measurement position B was obtained as the resistivity R1 (Ω / cm) of the negative electrode plate. Next, after removing the negative electrode material from the negative electrode plate, the resistance value of the negative electrode current collector (lattice body) was measured in the same manner as described above to obtain the resistivity R2 (Ω / cm) of the negative electrode current collector. Thereafter, a value (R1-R2) obtained by subtracting the resistivity R2 (Ω / cm) of the negative electrode current collector from the resistivity R1 (Ω / cm) of the negative electrode plate was obtained as the resistivity (Ω / cm) of the negative electrode material. .

(Examples 2 to 6, Comparative Examples 1 to 5)
Lead storage batteries of Examples 2 to 6 and Comparative Examples 1 to 5 were obtained in the same manner as in Example 1 except that the constituent components of the negative electrode material were changed to those shown in Table 1. The contents of carbon black, bisphenol-based resin, naphthalenesulfonic acid-based resin, and lignin sulfonate (based on solid content) based on the total mass of the negative electrode material after conversion were the contents shown in Table 1. As carbon black having a primary particle size of 30 nm, trade name: Vulcan XC72 manufactured by Cabot Corporation was used. As the carbon black having a primary particle size of 40 nm, powdery carbon black having a trade name: Denka Black manufactured by Denka Co., Ltd. was used.

<Evaluation of battery characteristics>
About the said 2V single cell battery, charge acceptance, discharge characteristics, and cycling characteristics were measured as follows. The measurement results of charge acceptability, discharge characteristics, and cycle characteristics of Comparative Example 1 were set to 100, and the characteristics of Examples and Comparative Examples were relatively evaluated. The results are shown in Table 1.

(Charge acceptance)
Charge capacity 5 seconds after the start of charging in a state where the state of charge of the battery is 90% (that is, a state in which 10% of the battery capacity is discharged from the fully charged state and charged at a constant voltage of 2.33 V) Was measured. The larger the charge capacity after 5 seconds, the better is the battery with better charge acceptance.

(Discharge characteristics)
As discharge characteristics, a constant current discharge was performed at −15 ° C. at 5 C, and the discharge duration until the battery voltage reached 1.0 V was measured. The longer the discharge duration, the better the battery. The C is a relative representation of the magnitude of current when the rated capacity is discharged at a constant current from a fully charged state. For example, a current that can discharge the rated capacity in 1 hour is expressed as 1 C, and a current that can be discharged in 2 hours is expressed as 0.5 C.

(Cycle characteristics)
The cycle characteristics were evaluated by a method according to a Japanese Industrial Standard light load life test (JIS D 5301). The larger the number of cycles, the higher the durability.

DESCRIPTION OF SYMBOLS 1 ... Lead acid battery, 2 ... Battery case, 3 ... Lid, 4 ... Positive electrode terminal, 5 ... Negative electrode terminal, 6 ... Liquid port stopper, 11 ... Electrode plate group, 12 ... Positive electrode plate, 13 ... Negative electrode plate, 14 ... Separator, DESCRIPTION OF SYMBOLS 15 ... Positive electrode side strap, 16 ... Negative electrode side strap, 17 ... Inter-cell connection part, 18 ... Polar pole, 22, 32 ... Current collection part.

Claims

A positive electrode and a negative electrode;
The negative electrode has a current collector and a negative electrode material held by the current collector;
The lead acid battery in which the resistivity of the negative electrode material when the state of charge is 0% is 1.02 Ω / cm or less.
The lead acid battery according to claim 1, wherein the negative electrode material contains carbon black.
The lead acid battery according to claim 2, wherein the average primary particle diameter of the carbon black is 50 nm or less.
4. The lead acid battery according to claim 2, wherein the content of the carbon black is 0.05 to 2% by mass based on the total mass of the negative electrode material.
The lead acid battery according to any one of claims 1 to 4, wherein the negative electrode material contains a resin having at least one selected from the group consisting of a sulfone group and a sulfonate group.
The resin is selected from the group consisting of bisphenol compounds and at least one selected from the group consisting of aminoalkyl sulfonic acids, aminoalkyl sulfonic acid derivatives, aminoaryl sulfonic acids and aminoaryl sulfonic acid derivatives, and formaldehyde and formaldehyde derivatives. The lead acid battery of Claim 5 containing the bisphenol-type resin which has a structural unit derived from reaction with at least 1 type.
The resin is a structural unit derived from the reaction of a bisphenol compound, at least one selected from the group consisting of aminobenzenesulfonic acid and aminobenzenesulfonic acid derivatives, and at least one selected from the group consisting of formaldehyde and formaldehyde derivatives. The lead acid battery of Claim 5 or 6 containing the bisphenol-type resin which has this.