JP6743919B2 - Lead-acid batteries, idling stop system vehicles and micro hybrid vehicles - Google Patents

Description

The present invention relates to a lead storage battery, an idling stop system vehicle, and a micro hybrid vehicle.

In recent years, in automobiles, various measures for improving fuel efficiency have been studied in order to prevent air pollution or global warming. Examples of automobiles that have been provided with measures for improving fuel economy include micro hybrid vehicles such as idling stop vehicles (hereinafter referred to as "ISS vehicles") that reduce the operating time of the engine, and power generation control vehicles that use the rotation of the engine for power without waste. Is being considered.

In an ISS vehicle, the number of times the engine is started increases, so that the large current discharge of the lead storage battery is repeated. Further, in the ISS vehicle and the power generation control vehicle, the amount of power generated by the alternator is small, and the lead storage battery is intermittently charged, so that charging is insufficient.

The lead acid battery used as described above is used in a partially charged state called PSOC (Partial State Of Charge). Lead-acid batteries have a shorter life when used under PSOC than when used in a fully charged state.

Furthermore, when intermittent charging and high-current discharge are repeated under PSOC as in ISS vehicle applications, the ears of the negative electrode current collector are likely to become lead sulfate, and the ears become thin and the ears rupture, resulting in a sudden life. It is known to reach.

On the other hand, Patent Document 1 listed below discloses a long-life lead-acid battery that delays the negative electrode deterioration of the battery when used in an ISS vehicle application and further delays the breakage of the ears, which does not result in a sudden life. In order to provide, the technique of using the negative electrode current collector containing Sn of a specific concentration and the electrolytic solution containing aluminum ions of a specific concentration is disclosed.

Patent No. 4515902

Patent Document 1 discloses that the deterioration of the negative electrode is delayed and the life of the lead storage battery can be extended by delaying the life of the lead storage battery more suddenly. However, lead batteries for ISS vehicles are required to have a longer life.

By the way, when a lead-acid battery is used in a state where the battery is not fully charged and the battery is insufficiently charged, the difference in concentration of dilute sulfuric acid, which is the electrolytic solution, between the upper and lower parts of the electrodes (electrode plates, etc.) inside the battery. The stratification phenomenon occurs. In this case, the concentration of dilute sulfuric acid in the lower part of the electrode is increased and sulfation occurs. Therefore, the reactivity of the lower part of the electrode is lowered and only the upper part of the electrode reacts intensively. As a result, deterioration such as weakening the bond between the active materials progresses, and the active material peels off from the lattice at the upper part of the electrode, which leads to deterioration of battery performance and early life.

Therefore, in recent lead acid batteries for automobiles, in order to improve the life performance of the battery when used under PSOC, it is extremely important to improve charge acceptability.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a lead storage battery having excellent charge acceptance and excellent ISS cycle characteristics.

In order to solve the above problems, the present inventors have proposed a lead storage battery including a positive electrode, a negative electrode, and an electrolytic solution, in which the negative electrode has a negative electrode material and a negative electrode current collector, and the negative electrode material has a bisphenol-based resin and a negative electrode active material. It was found that the above-mentioned problem can be solved by including the following, and the negative electrode current collector has an ear portion, and the ear portion is formed with a surface layer of Sn or a Sn alloy.

That is, the lead storage battery according to the present invention is a lead storage battery including a positive electrode, a negative electrode, and an electrolytic solution, wherein the negative electrode has a negative electrode material and a negative electrode current collector, and the negative electrode material is a bisphenol-based resin and a negative electrode active material. , And the negative electrode current collector has a ears, and the ears have a surface layer of Sn or Sn alloy formed thereon.

According to the lead storage battery of the present invention, it is possible to obtain excellent charge acceptability. Therefore, the SOC, which tends to be low in ISS vehicles, micro hybrid vehicles, etc., can be maintained at an appropriate level, especially after the active material is sufficiently activated by repeating charge and discharge to some extent from the initial state. .. Further, according to the lead acid battery of the present invention, it is possible to obtain excellent charge acceptance and obtain excellent ISS cycle characteristics under PSOC.

Further, according to the lead acid battery of the present invention, since the electrolytic solution contains aluminum ions, it is possible to obtain further excellent charge acceptability and excellent ISS cycle characteristics under PSOC.

According to the lead storage battery of the present invention, it is possible to obtain excellent charge acceptability. Further, the lead-acid battery according to the present invention has excellent ISS cycle characteristics under PSOC. INDUSTRIAL APPLICABILITY The lead storage battery according to the present invention can be suitably used in an ISS vehicle, a micro hybrid vehicle, etc. as a liquid lead storage battery in which charging is performed intermittently and high rate discharge to a load is performed under PSOC.

According to the present invention, an application of a lead storage battery to a micro hybrid vehicle can be provided. According to the present invention, it is possible to provide an application of a lead storage battery to an ISS vehicle.

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

<Lead storage battery>
The lead storage battery according to the present embodiment includes, for example, an electrode (electrode plate or the like), an electrolytic solution (sulfuric acid or the like), and a separator. The electrode has a positive electrode (a positive electrode plate or the like) and a negative electrode (a negative electrode plate or the like). Examples of the lead storage battery according to the present embodiment include a liquid lead storage battery, a control valve type lead storage battery, and a sealed lead storage battery, and the liquid lead storage battery is preferable. The positive electrode has a current collector (positive electrode current collector) and a positive electrode material held by the current collector. The negative electrode has a current collector (negative electrode current collector) and a negative electrode material held by the current collector. In this embodiment, the positive electrode material and the negative electrode material are, for example, electrode materials after chemical conversion (for example, in a fully charged state). When the electrode material is unformed, the electrode material (unmade positive electrode material and unmade negative electrode material) contains raw materials of the electrode active material (positive electrode active material and negative electrode active material) and the like. The current collector constitutes a conductive path for current from the electrode material.

(Cathode material)
[Cathode active material]
The positive electrode material contains a positive electrode active material. The positive electrode active material can be obtained by aging and drying a positive electrode material paste containing a raw material of the positive electrode active material to obtain an unformed active material and then performing chemical conversion. The positive electrode active material after chemical conversion preferably contains β-lead dioxide (β-PbO ₂ ), and may further contain α-lead dioxide (α-PbO ₂ ). The raw material of the positive electrode active material is not particularly limited, and examples thereof include lead powder. As the lead powder, for example, lead powder produced by a ball mill type lead powder manufacturing machine or a Burton pot type lead powder manufacturing machine (in the ball mill type lead powder manufacturing machine, a mixture of powder of the main component PbO and scale-like metallic lead). Is mentioned. Lead tin (Pb ₃ O ₄ ) may be used as a raw material of the positive electrode active material. The unformed positive electrode material preferably contains an unformed positive electrode active material containing tribasic lead sulfate as a main component.

[Cathode additive]
The positive electrode material may further contain an additive. Examples of the additives include carbon materials (carbonaceous conductive materials) and reinforcing short fibers. Examples of the carbon material include carbon black and graphite. Examples of carbon black include furnace black (Ketjen black, etc.), channel black, acetylene black, thermal black and the like. Examples of the reinforcing short fibers include acrylic fibers, polyethylene fibers, polypropylene fibers, polyethylene terephthalate fibers, carbon fibers and the like.

(Negative electrode material)
[Negative electrode active material]
The negative electrode active material can be obtained by aging the negative electrode material paste containing the raw material of the negative electrode active material to obtain an unformed active material, and then performing chemical conversion. Examples of the negative electrode active material after chemical conversion include spongy lead. The spongy lead tends to react with sulfuric acid in the electrolytic solution and gradually change to lead sulfate (PbSO ₄ ). Examples of the raw material for the negative electrode active material include lead powder. As the lead powder, for example, lead powder produced by a ball mill type lead powder manufacturing machine or a Burton pot type lead powder manufacturing machine (in the ball mill type lead powder manufacturing machine, a mixture of powder of the main component PbO and scale-like metallic lead). Is mentioned. The unformed negative electrode material is composed of, for example, basic lead sulfate and metallic lead, and a lower oxide.

[Negative electrode additive]
The negative electrode material further contains an additive. In the lead-acid battery according to the present embodiment, the negative electrode material contains (A) bisphenol resin, and may contain (B) other additives. The (A) bisphenol resin includes, for example, (a) bisphenol compound and (b) amino acid, amino acid derivative, aminoalkylsulfonic acid, aminoalkylsulfonic acid derivative, aminoarylsulfonic acid and aminoarylsulfonic acid derivative. Examples thereof include resins obtained by reacting at least one selected from the group with at least one selected from the group consisting of (c) formaldehyde and a formaldehyde derivative.
Hereinafter, the (A) bisphenol resin will be described in detail, but the invention is not limited thereto.

<(A) Bisphenol resin>
(Component (a): Bisphenol compound)
The bisphenol compound is a compound having two hydroxyphenyl groups. Examples of the bisphenol compound include 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, and bis(4-hydroxyphenyl)sulfone (Hereinafter, referred to as “bisphenol S”).

The bisphenol compounds can be used alone or in combination of two or more. As the bisphenol compound, bisphenol A is preferable from the viewpoint of further excellent charge acceptability, and bisphenol S is preferable from the viewpoint of further excellent discharge characteristics.

As the bisphenol-based compound, it is preferable to use bisphenol A and bisphenol S in combination, from the viewpoint of well-balanced improvement of charge acceptability, discharge characteristics and cycle characteristics. In this case, the compounding amount of bisphenol A for obtaining the (A) bisphenol resin is 70 mol based on the total amount of bisphenol A and bisphenol S from the viewpoint of improving the charge acceptability, discharge characteristics and cycle characteristics in a well-balanced manner. % Or more, preferably 75 mol% or more, more preferably 80 mol% or more. The blending amount of bisphenol A is preferably 99 mol% or less, more preferably 98 mol% or less, and 97 mol% or less, based on the total amount of bisphenol A and bisphenol S, from the viewpoint that charge acceptability, discharge characteristics and cycle characteristics are improved in a well-balanced manner. % Or less is more preferable.

(Component (b): amino acid, amino acid derivative, aminoalkylsulfonic acid, aminoalkylsulfonic acid derivative, aminoarylsulfonic acid and aminoarylsulfonic acid derivative)
Examples of amino acids include glycine, alanine, phenylalanine, aspartic acid and glutamic acid. Examples of the amino acid derivative include alkali metal salts in which the hydrogen atom of the carboxyl group of the amino acid is replaced with an alkali metal. Among amino acids and amino acid derivatives, glutamic acid and its alkali metal salts are particularly preferable. Examples of the alkali metal salt include sodium salt and potassium salt.

Examples of aminoalkyl sulfonic acids and aminoalkyl sulfonic acid derivatives include compounds represented by the following general formula (I). Examples of the aminoalkylsulfonic acid include compounds in which X ¹ is a hydrogen atom in the following general formula (I). Examples of the aminoalkyl sulfonic acid derivative include alkali metal salts in which X ¹ is an alkali metal in the following general formula (I).

［式（Ｉ）中、Ｒ^１は、水素原子又は炭化水素基を示し、Ｘ^１は、アルカリ金属又は水素原子を示し、ｎ１は、０〜３の整数を示す。］

[In the formula (I), R ¹ represents a hydrogen atom or a hydrocarbon group, X ¹ represents an alkali metal or a hydrogen atom, and n1 represents an integer of 0 to 3. ]

As the hydrocarbon group for R ¹ in formula (I), for example, a linear, branched or cyclic hydrocarbon group can be mentioned. Examples of the linear or branched hydrocarbon group include a linear or branched alkyl group. Examples of the cyclic hydrocarbon group include alicyclic hydrocarbon groups. The number of carbon atoms of the hydrocarbon group is preferably 1 or more from the viewpoint of well-balanced improvement in charge acceptability, discharge characteristics and cycle characteristics. The number of carbon atoms in the hydrocarbon group is preferably 6 or less, more preferably 5 or less, and even more preferably 3 or less, from the viewpoint of improving charge acceptance, discharge characteristics and cycle characteristics in a well-balanced manner.

Examples of the linear or branched alkyl group include methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, s-butyl group, isobutyl group, t-butyl group, n-pentyl group, isopentyl group. Group, t-pentyl group, n-hexyl group, isohexyl group, s-hexyl group and t-hexyl group. Examples of the alicyclic hydrocarbon group include an alicyclic alkyl group, and specific examples include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group and a cyclohexyl group. As R ¹ , a hydrogen atom and a linear or branched alkyl group having 1 to 6 carbon atoms are preferable, and a hydrogen atom and a methyl group, from the viewpoint of well-balanced improvement in charge acceptability, discharge characteristics, and cycle characteristics. Is more preferable.

Examples of the alkali metal for X ¹ in formula (I) include sodium and potassium. X ¹ is preferably sodium from the viewpoint of improving the charge acceptability, discharge characteristics and cycle characteristics in a well-balanced manner. n1 is preferably 0 to 2, and more preferably 0 or 1 from the viewpoint of improving the charge acceptability, discharge characteristics, and cycle characteristics in a well-balanced manner.

Examples of the aminoalkylsulfonic acid include aminomethanesulfonic acid, 2-aminoethanesulfonic acid, 3-aminopropanesulfonic acid, and 2-methylaminoethanesulfonic acid, and 2-aminoethanesulfonic acid is preferable.

Examples of the aminoaryl sulfonic acid include aminobenzene sulfonic acid and aminonaphthalene sulfonic acid. Examples of the aminoaryl sulfonic acid derivative include an aminobenzene sulfonic acid derivative and an aminonaphthalene sulfonic acid derivative.

Examples of aminobenzene sulfonic acid include 2-aminobenzene sulfonic acid (also known as orthanilic acid), 3-aminobenzene sulfonic acid (also known as methanilic acid), and 4-aminobenzene sulfonic acid (also known as sulfanilic acid).

Examples of the aminobenzenesulfonic acid derivative include a compound in which some hydrogen atoms of aminobenzenesulfonic acid are substituted with an alkyl group (for example, an alkyl group having 1 to 5 carbon atoms), and a sulfo group of aminobenzenesulfonic acid. hydrogen atom (-SO 3 _H) and the alkali metal salts substituted with an alkali metal (e.g. sodium or potassium). Examples of the compound in which a part of hydrogen atoms of aminobenzenesulfonic acid are substituted with an alkyl group include 4-(methylamino)benzenesulfonic acid, 3-methyl-4-aminobenzenesulfonic acid and 3-amino-4-. Examples thereof include methylbenzenesulfonic acid, 4-(ethylamino)benzenesulfonic acid, and 3-(ethylamino)-4-methylbenzenesulfonic acid. Examples of the alkali metal salt in which the hydrogen atom of the sulfo group of aminobenzenesulfonic acid is replaced with an alkali metal include, for example, sodium 2-aminobenzenesulfonate, sodium 3-aminobenzenesulfonate, sodium 4-aminobenzenesulfonate, and 2 -Potassium aminobenzene sulfonate, potassium 3-aminobenzene sulfonate, and potassium 4-aminobenzene sulfonate.

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- Aminonaphthalenemonosulfonic acid such as naphthalenesulfonic acid, 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, 6-amino-1,3-naphthalenedisulfonic acid, 7 -Amino-1,3-naphthalenedisulfonic acid and other aminonaphthalenedisulfonic acids; 7-amino-1,3,6-naphthalene trisulfonic acid, 8-amino-1,3,6-naphthalene trisulfonic acid and other aminonaphthalene Trisulfonic acid may be mentioned.

Examples of the aminonaphthalenesulfonic acid derivative include a compound in which a part of hydrogen atoms of aminonaphthalenesulfonic acid is replaced with an alkyl group (for example, an alkyl group having 1 to 5 carbon atoms), and a sulfo group of aminonaphthalenesulfonic acid. An alkali metal salt in which a hydrogen atom of (—SO ₃ H) is replaced with an alkali metal can be given. Examples of alkali metal salts include monoalkali metal salts and dialkali metal salts. As the alkali metal salt, a sodium salt and a potassium salt are preferable, and a sodium salt is more preferable, from the viewpoint of well-balanced improvement in charge acceptability, discharge characteristics and cycle characteristics.

As the aminonaphthalene sulfonic acid and the aminonaphthalene sulfonic acid derivative, a compound represented by the following general formula (II) is preferable from the viewpoint of well-balanced improvement in charge acceptability, discharge characteristics and cycle characteristics. Examples of the alkali metal for R ² include sodium and potassium. n2 is preferably 1 or 2, and more preferably 1 from the viewpoint of improving the charge acceptability, discharge characteristics and cycle characteristics in a well-balanced manner. When n2 is 2 or 3, R ² may be the same as or different from each other.

［式（ＩＩ）中、Ｒ^２は、アルカリ金属又は水素原子を示し、ｎ２は、１〜３の整数を示す。］

[In the formula (II), R ² represents an alkali metal or a hydrogen atom, and n ² represents an integer of 1 to 3. ]

As the component (b), one type can be used alone, or two or more types can be used in combination. As the component (b), aminoalkyl sulfonic acid, aminoalkyl sulfonic acid derivative, aminoaryl sulfonic acid and aminoaryl sulfonic acid derivative are preferable, and 2-aminoethane sulfonic acid, from the viewpoint of further improving charge acceptability and cycle characteristics. , 4-aminobenzenesulfonic acid and sodium 7-amino-2-naphthalenesulfonate are more preferable.

The blending amount of the component (b) for obtaining the bisphenol resin (A) is preferably 0.5 mol or more, and more preferably 0.6 mol or more with respect to 1 mol of the component (a) from the viewpoint of further improving the discharge characteristics. It is preferably 0.8 mol or more, more preferably 0.9 mol or more. The blending amount of the component (b) is preferably 1.3 mol or less, more preferably 1.2 mol or less, and 1.1 mol or less with respect to 1 mol of the component (a) from the viewpoint that the discharge characteristics and the cycle characteristics are more easily improved. The following is more preferable.

(Component (c): formaldehyde and formaldehyde derivative)
As the formaldehyde, formaldehyde in formalin (for example, a 37% by mass formaldehyde aqueous solution) may be used. Examples of formaldehyde derivatives include paraformaldehyde, hexamethylenetetramine and trioxane. (C)
The components may be used alone or in combination of two or more. You may use formaldehyde and a formaldehyde derivative together.

As the component (c), a formaldehyde derivative is preferable, and paraformaldehyde is more preferable, from the viewpoint of easily obtaining excellent cycle characteristics. Paraformaldehyde has a structure represented by the following general formula (III), for example.
HO(CH ₂ O) _{n 3} H (III)
[In formula (III), n3 shows the integer of 2-100. ]

From the viewpoint of improving the reactivity of the component (b), the compounding amount of the component (c) in terms of formaldehyde for obtaining the bisphenol resin (A) is preferably 2 mol or more per 1 mol of the component (a). 0.2 mol or more is more preferable, and 2.4 mol or more is further preferable. From the viewpoint of excellent solubility of the component (c) in formaldehyde in the solvent of the bisphenol resin (A), 3.5 mol or less is preferable and 3.2 mol or less relative to 1 mol of the component (a). More preferably, 3 mol or less is further preferable.

When an aminoalkyl sulfonic acid, an aminoalkyl sulfonic acid derivative, an aminoaryl sulfonic acid or an aminoaryl sulfonic acid derivative is used as the component (b), the bisphenol resin (A) is a structural unit represented by the following formula (IV): It is also preferable to have at least one selected from the group consisting of structural units represented by the following formula (V).

［式（ＩＶ）中、Ｘ^４は、２価の基を示し、Ａ^４は、アルキレン基又はアリーレン基を示し、Ｒ^４１は、アルカリ金属又は水素原子を示し、Ｒ^４２は、メチロール基（−ＣＨ_２ＯＨ）を示し、Ｒ^４３及びＲ^４４は、それぞれ独立にアルカリ金属又は水素原子を示し、ｎ４１は、１〜６００の整数を示し、ｎ４２は、１〜３の整数を示し、ｎ４３は、０又は１を示す。］

[In the formula (IV), X ⁴ represents a divalent group, A ⁴ represents an alkylene group or an arylene group, R ⁴¹ represents an alkali metal or a hydrogen atom, and R ⁴² represents a methylol group (- CH ₂ OH), R ⁴³ and R ⁴⁴ each independently represent an alkali metal or a hydrogen atom, n41 represents an integer of 1 to 600, n42 represents an integer of 1 to 3, and n43 represents Indicates 0 or 1. ]

［式（Ｖ）中、Ｘ^５は、２価の基を示し、Ａ^５は、アルキレン基又はアリーレン基を示し、Ｒ^５１は、アルカリ金属又は水素原子を示し、Ｒ^５２は、メチロール基（−ＣＨ_２ＯＨ）を示し、Ｒ^５３及びＲ^５４は、それぞれ独立にアルカリ金属又は水素原子を示し、ｎ５１は、１〜６００の整数を示し、ｎ５２は、１〜３の整数を示し、ｎ５３は、０又は１を示す。］

[In the formula (V), X ⁵ represents a divalent group, A ⁵ represents an alkylene group or an arylene group, R ⁵¹ represents an alkali metal or a hydrogen atom, and R ⁵² represents a methylol group (- CH ₂ OH), R ⁵³ and R ⁵⁴ each independently represent an alkali metal or a hydrogen atom, n51 represents an integer of 1 to 600, n52 represents an integer of 1 to 3, and n53 represents Indicates 0 or 1. ]

When an amino acid or an amino acid derivative is used as the component (b), the bisphenol resin (A) is composed of a structural unit represented by the following formula (VI) and a structural unit represented by the following formula (VII). It is preferable to have at least one selected.

［式（ＶＩ）中、Ｘ^６は、２価の基を示し、Ａ^６は、アルキレン基又はアリーレン基を示し、Ｒ^６１は、アルカリ金属又は水素原子を示し、Ｒ^６２は、メチロール基（−ＣＨ_２ＯＨ）を示し、Ｒ^６３及びＲ^６４は、それぞれ独立にアルカリ金属又は水素原子を示し、ｎ６１は、１〜６００の整数を示し、ｎ６２は、１〜３の整数を示し、ｎ６３は、０又は１を示す。］

[In the formula (VI), X ⁶ represents a divalent group, A ⁶ represents an alkylene group or an arylene group, R ⁶¹ represents an alkali metal or a hydrogen atom, and R ⁶² represents a methylol group (- CH ₂ OH), R ⁶³ and R ⁶⁴ each independently represent an alkali metal or a hydrogen atom, n61 represents an integer of 1 to 600, n62 represents an integer of 1 to 3, n63 represents Indicates 0 or 1. ]

［式（ＶＩＩ）中、Ｘ^７は、２価の基を示し、Ａ^７は、アルキレン基又はアリーレン基を示し、Ｒ^７１は、アルカリ金属又は水素原子を示し、Ｒ^７２は、メチロール基（−ＣＨ_２ＯＨ）を示し、Ｒ^７３及びＲ^７４は、それぞれ独立にアルカリ金属又は水素原子を示し、ｎ７１は、１〜６００の整数を示し、ｎ７２は、１〜３の整数を示し、ｎ７３は、０又は１を示す。］

[In the formula (VII), X ⁷ represents a divalent group, A ⁷ represents an alkylene group or an arylene group, R ⁷¹ represents an alkali metal or a hydrogen atom, and R ⁷² represents a methylol group (- CH ₂ OH), R ⁷³ and R ⁷⁴ each independently represent an alkali metal or a hydrogen atom, n71 represents an integer of 1 to 600, n72 represents an integer of 1 to 3, and n73 represents Indicates 0 or 1. ]

The ratio of the structural unit represented by the formula (IV) and the structural unit represented by the formula (V) is not particularly limited and may be changed depending on the synthesis conditions and the like. As the bisphenol-based resin (A), a resin having only one of the structural unit represented by the formula (IV) and the structural unit represented by the formula (V) may be used. The ratio of the structural unit represented by the formula (VI) and the structural unit represented by the formula (VII) is not particularly limited and may be changed depending on the synthesis conditions and the like. As the bisphenol resin (A), a resin having only one of the structural unit represented by the formula (VI) and the structural unit represented by the formula (VII) may be used.

Examples of X ⁴ , X ⁵ , X ⁶ and X ⁷ include an alkylidene group (methylidene group, ethylidene group, isopropylidene group, sec-butylidene group and the like), cycloalkylidene group (cyclohexylidene group and the like), phenylalkylidene group Organic groups such as (diphenylmethylidene group, phenylethylidene group, etc.); sulfonyl groups, and isopropylidene group (—C(CH ₃ ) ₂ —) group are preferable from the viewpoint of further excellent charge acceptability, and discharge characteristics A sulfonyl group (—SO ₂ —) is preferable from the viewpoint of further excellent X ⁴ , X ⁵ , X ⁶ and X ⁷ may be substituted with a halogen atom such as a fluorine atom. When X ⁴ , X ⁵ , X ⁶ and X ⁷ are cycloalkylidene groups, the hydrocarbon ring may be substituted with an alkyl group or the like.

Examples of A ⁴ , A ⁵ , A ⁶ and A ⁷ include an alkylene group having 1 to 4 carbon atoms such as a methylene group, an ethylene group, a propylene group and a butylene group; a divalent arylene group such as a phenylene group and a naphthylene group. Is mentioned. The arylene group may be substituted with an alkyl group or the like.

Examples of the alkali metal of R ⁴¹ , R ⁴³ , R ⁴⁴ , R ⁵¹ , R ⁵³ , R ⁵⁴ , R ⁶¹ , R ⁶³ , R ⁶⁴ , R ⁷¹ , R ^73, and R ⁷⁴ include sodium and potassium. n41, n51, n61 and n71 are preferably 5 to 300 from the viewpoint of further excellent cycle characteristics and solubility in a solvent. n42, n52, n62 and n72 are preferably 1 or 2 and more preferably 1 from the viewpoint of improving the charge acceptability, discharge characteristics and cycle characteristics in a well-balanced manner. Although n43, n53, n63 and n73 change depending on the production conditions, 0 is preferable from the viewpoints of further excellent cycle characteristics and excellent storage stability of the (A) bisphenol resin.

The weight average molecular weight of the (A) bisphenol resin is preferably 3000 or more from the viewpoint that cycle characteristics are easily improved by suppressing the elution of the (A) bisphenol resin from the electrode into the electrolytic solution in the lead storage battery, It is more preferably 10,000 or more, further preferably 20,000 or more, particularly preferably 30,000 or more. The weight average molecular weight of the (A) bisphenol-based resin is preferably 200,000 or less, and preferably 150,000 or less, from the viewpoint that cycle characteristics are easily improved by suppressing a decrease in the adsorptivity to the electrode active material and a decrease in the dispersibility. Is more preferable, and 100,000 or less is further preferable.

The weight average molecular weight of the bisphenol-based resin (A) can be measured, for example, by gel permeation chromatography (hereinafter referred to as “GPC”) under the following conditions.
(GPC condition)
Device: High Performance Liquid Chromatograph LC-2200 Plus (manufactured by JASCO Corporation)
Pump: PU-2080
Differential Refractometer: RI-2031
Detector: UV-visible absorption 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) 0.06×10 ² ; manufactured by Kishida Chemical Co., Ltd.), dibutylhydroxytoluene (molecular weight: 2.20×10 ² ; manufactured by Kishida Chemical Co., Ltd.)

The bisphenol-based resin (A) can be obtained, for example, by reacting the components (a), (b) and (c) in a reaction solvent. The reaction solvent is preferably water (for example, ion-exchanged water). An organic solvent, a catalyst, an additive or the like may be used to accelerate the reaction.

In the resin manufacturing process for obtaining the (A) bisphenol-based resin, the blending amount of the component (b) is 0.5 to 1.3 mol with respect to 1 mol of the component (a) from the viewpoint of further improving the cycle characteristics, and It is preferable that the compounding amount of the component (c) is 2 to 3.5 mol in terms of formaldehyde with respect to 1 mol of the component (a). The preferable blending amounts of the component (b) and the component (c) are in the ranges described above for the respective blending amounts of the component (b) and the component (c).

The bisphenol resin (A) is obtained by reacting the components (a), (b) and (c) under basic conditions (alkaline conditions) from the viewpoint of easily obtaining a sufficient amount of the (A) bisphenol resin. It is preferable to obtain A basic compound may be used to adjust to basic conditions. Examples of the basic compound include sodium hydroxide, potassium hydroxide and sodium carbonate. The basic compounds may be used alone or in combination of two or more. Among the basic compounds, sodium hydroxide and potassium hydroxide are preferable from the viewpoint of excellent reactivity.

When the reaction solution at the time of reaction is neutral (pH=7), the production reaction of the (A) bisphenol resin may be difficult to proceed, and when the reaction solution is acidic (pH<7), side reactions may occur. It may progress. Therefore, the pH of the reaction solution at the time of reaction is preferably alkaline (exceeds 7) from the viewpoint of suppressing the progress of side reactions while promoting the production reaction of the (A) bisphenol resin. 1 or more is more preferable, and 7.2 or more is still more preferable. The pH of the reaction solution is preferably 13 or less, more preferably 10 or less, and further preferably 9 or less, from the viewpoint of suppressing the progress of hydrolysis of the group derived from the component (b) of the (A) bisphenol resin. .. The pH of the reaction solution can be measured, for example, by Twin pH manufactured by As One Co., Ltd. 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, and 1.03 mol or more with respect to 1 mol of the component (b). 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, still more preferably 1.07 mol or less, relative to 1 mol of the component (b). Examples of the strongly basic compound include sodium hydroxide and potassium hydroxide.

In the present embodiment, the reaction product (reaction solution) obtained when producing the (A) bisphenol resin may be used as it is for the production of an electrode described below, or may be obtained by drying the reaction product (A). The bisphenol-based resin may be dissolved in a solvent (water or the like) and used in the production of the electrode described later.

The pH of the resin solution containing the (A) bisphenol resin (for example, a liquid resin solution at 25° C.) is alkaline from the viewpoint of excellent solubility of the (A) bisphenol resin in a solvent (water or the like) (7 Is more preferable), and 7.1 or more is more preferable. From the viewpoint of improving the storage stability of the resin composition, the pH of the resin solution is preferably 10 or less, more preferably 9 or less, and further preferably 8.5 or less. In particular, when the reaction product obtained in the resin production process is used as a resin solution, the pH of the resin solution is preferably within the above range. The pH of the resin solution can be measured by, for example, Twin pH manufactured by As One Co., Ltd. pH is defined as the pH at 25°C.

The synthesis reaction of the (A) bisphenol resin may be carried out by reacting the components (a), (b) and (c) to obtain the (A) bisphenol resin. For example, the components (a), (b) The component) and the component (c) may be reacted at the same time, or two components among the components (a), (b) and (c) may be reacted and then the remaining one component may be reacted.

The synthesis reaction of the bisphenol resin (A) is preferably performed in two steps as follows.
In the first-step reaction, for example, the component (b), the solvent (water, etc.) and the basic compound are charged and then stirred, and the hydrogen atom of the sulfo group in the component (b) is replaced with an alkali metal or the like (b ) Component alkali metal salt and the like are obtained. This facilitates suppression of side reactions in the condensation reaction described below. 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 the component (b) in the solvent (water or the like). From the viewpoint of suppressing side reactions, the temperature of the reaction system is preferably 80°C or lower, more preferably 70°C or lower, and even more preferably 65°C or lower. The reaction time is, for example, 30 minutes.

In the reaction in the second step, for example, the component (a) and the component (c) are added to the reaction product obtained in the first step and a condensation reaction is performed to obtain the bisphenol resin (A). The temperature of the reaction system is preferably 75° C. or higher, more preferably 85° C. or higher, still more preferably 87° C. or higher, from the viewpoint of excellent reactivity of the components (a), (b) and (c). From the viewpoint of suppressing side reactions, the temperature of the reaction system is preferably 100°C or lower, more preferably 95°C or lower, and further preferably 93°C or lower. The reaction time is, for example, 5 to 20 hours.

The reaction product thus obtained is dried to remove the solvent (water and the like) and the unreacted component (c) and the like, whereby the bisphenol resin (A) is obtained. The drying method is not particularly limited, but a method in which the temperature of the (A) bisphenol resin is 100° C. or lower is preferable from the viewpoint of preventing the self-curing reaction of the (A) bisphenol resin. Examples of the drying method include reduced pressure drying, freeze drying and spray drying.

The lead storage battery according to the present invention is excellent in charge acceptance because the negative electrode material contains the (A) bisphenol resin. Further, in the lead storage battery according to the present invention, since the negative electrode material contains the (A) bisphenol-based resin, the ears of the negative electrode current collector are less likely to break and the life is less likely to suddenly increase, so that the ISS cycle characteristics are excellent. It is not clear why the negative electrode material contains the (A) bisphenol resin so that the ears of the negative electrode current collector are less likely to break, but the potential of the ears is higher than the dissolution and precipitation potentials of lead sulfate. It is assumed that the potential changes and the ears are less likely to break.

[(B) Other additives]
The negative electrode material may contain (B) other additives. (B) Other additives include, for example, barium sulfate, carbon materials (carbonaceous conductive materials), reinforcing short fibers, and the like.

[Carbon material (carbonaceous conductive material)]
Examples of the carbonaceous conductive material include graphite, carbon black, activated carbon, carbon fiber, and carbon nanotube. The amount of the carbonaceous conductive material added is preferably 0.1 to 3 parts by mass with respect to 100 parts by mass of the fully charged negative electrode active material (spongeous metallic lead). Graphite is preferable from the viewpoint of improving charge acceptability, and flake graphite is more preferable from the viewpoint of improving charge acceptability. The average primary particle size of the flake graphite is preferably 100 μm to 500 μm, more preferably 100 μm to 350 μm, and further preferably 100 μm to 220 μm, from the viewpoint of improving the charge acceptability.

The flake graphite referred to here is one described in JIS M 8601 (2005). The electrical resistivity of the flake graphite is 0.02 Ω·cm or less, which is an order of magnitude smaller than about 0.1 Ω·cm of carbon blacks such as acetylene black. Therefore, by using the flake graphite in place of the carbon blacks used in conventional lead-acid batteries, it is possible to reduce the electric resistance of the negative electrode active material and improve the charge acceptance performance.

Here, the average primary particle diameter of the flake graphite is determined according to the laser diffraction/scattering method described in JISM8511 (2005). Using a laser diffraction/scattering particle size distribution analyzer (manufactured by Nikkiso Co., Ltd.: Microtrac 9220FRA), a commercially available surfactant polyoxyethylene octyl phenyl ether as a dispersant (for example, manufactured by Roche Diagnostics KK: Triton) X-100) is added to an aqueous solution containing 0.5 vol% of a flake graphite sample in an appropriate amount, and ultrasonic waves of 40 W are irradiated for 180 seconds while stirring, and then the measurement is performed. The value of the obtained average particle diameter (median diameter: D50) is defined as the average primary particle diameter.

[Reinforcing short fibers]
Examples of the reinforcing short fiber include acrylic fiber, polyethylene fiber, polypropylene fiber, polyethylene terephthalate fiber, and carbon fiber.

(Electrolyte)
The electrolytic solution preferably contains sulfuric acid and aluminum ions, and can be obtained, for example, by mixing sulfuric acid and aluminum sulfate powder. Aluminum sulfate to be dissolved in the electrolytic solution can be added as an anhydride or a hydrate.

The specific gravity of the electrolytic solution (which may contain aluminum ions) (specific gravity is defined as the specific gravity converted at 20° C. in the present specification because the specific gravity changes with temperature. The same applies hereinafter) in the following range. Preferably. The specific gravity of the electrolytic solution is preferably 1.25 or more, more preferably 1.28 or more, further preferably 1.285 or more, and more preferably 1.29 or more, from the viewpoint of suppressing permeation short circuit or freezing and further excellent in discharge characteristics. Particularly preferred. The specific gravity of the electrolytic solution is preferably 1.33 or less, more preferably 1.32 or less, further preferably 1.315 or less, and particularly preferably 1.31 or less, from the viewpoint of further improving charge acceptability and cycle characteristics. The value of the specific gravity of the electrolytic solution can be measured by, for example, a floating hydrometer or a digital hydrometer manufactured by Kyoto Electronics Manufacturing Co., Ltd.

The aluminum ion concentration of the electrolytic solution is preferably 0.01 mol/L or more, more preferably 0.02 mol/L or more, still more preferably 0.03 mol/L or more, from the viewpoint of further improving the charge acceptability and ISS cycle characteristics. .. The aluminum ion concentration of the electrolytic solution is preferably 0.2 mol/L or less, more preferably 0.15 mol/L or less, still more preferably 0.13 mol/L or less, from the viewpoint of further improving charge acceptability and ISS cycle characteristics. .. The aluminum ion concentration of the electrolytic solution can be measured, for example, by ICP emission spectroscopy (high frequency inductively coupled plasma emission spectroscopy).

Although the details of the mechanism of improving the charge acceptability when the aluminum ion concentration of the electrolytic solution is within the above-mentioned predetermined range are not clear, in an electrolytic solution of crystalline lead sulfate which is a discharge product under an arbitrary low SOC. It is considered that the solubility of the electrolyte is increased or the diffusivity of the electrolytic solution into the electrode active material is improved due to the high ionic conductivity of aluminum ions.

Further, although the mechanism by which the aluminum ion concentration of the electrolytic solution is within the predetermined range to improve the ISS cycle characteristics is not known in detail, the potential of the ears of the negative electrode plate is higher than the potential of dissolution and precipitation of lead sulfate. It is presumed that the electric potential changes to a high level and the ears are less likely to break.

(Separator)
Examples of the separator include a separator made of at least one selected from glass, pulp, and synthetic resin. Among the separators, it is preferable to use a synthetic resin from the viewpoint of further suppressing a short circuit. Further, among the above synthetic resins, polyolefin is particularly preferable.

<Lead storage battery manufacturing method>
The method for manufacturing a lead storage battery according to the present embodiment includes, for example, an electrode manufacturing process for obtaining electrodes (a positive electrode and a negative electrode) and an assembly process for assembling a component including the electrodes to obtain a lead storage battery.

In the electrode manufacturing process, for example, aging and drying are performed after the electrode material paste (positive electrode material paste and negative electrode material paste) is filled in a current collector (for example, a current collector grid such as a cast grid body or an expanded grid body). As a result, an unformed electrode 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 the raw material of the negative electrode active material (lead powder or the like) and the bisphenol resin, and may further contain other additives.

The positive electrode material paste can be obtained, for example, by the following method. First, an additive (reinforcing short fibers, etc.) and water are added to the raw material of the positive electrode active material. Next, dilute sulfuric acid is added and then kneaded to obtain a positive electrode material paste. In producing the positive electrode material paste, lead tin (Pb ₃ O ₄ ) may be used as a raw material of the positive electrode active material from the viewpoint of shortening the formation time. An unformed positive electrode can be obtained by filling the current collector with this positive electrode material paste and then aging and drying.

When the reinforcing short fibers are used in the positive electrode material paste, the content of the reinforcing short fibers is preferably 0.005 to 0.3% by mass, based on the total mass of the raw materials (lead powder etc.) of the positive electrode active material, 0.05 to 0.3 mass% is more preferable.

The maturing conditions for obtaining the unformed positive electrode are preferably 15 to 60 hours in an atmosphere of a temperature of 35 to 85° C. and a humidity of 50 to 98 RH%. The drying conditions are preferably 45 to 80° C. for 15 to 30 hours.

The negative electrode current collector of the lead storage battery according to this embodiment will be described. Examples of the composition of the current collector include a lead-calcium-tin alloy, a lead-calcium alloy, and a lead-antimony alloy. A current collector can be obtained by forming these lead alloys in a grid shape by a gravity casting method, an expanding method, a punching method or the like.

The negative electrode current collector includes a grid portion and strip-shaped portions that are continuously provided on the upper and lower edges thereof. An upper frame part is connected to a band-shaped part on the upper edge side of the band-shaped part, and an ear part for collecting current is formed in the upper frame part.

The ears of the negative electrode current collector according to the present invention have a surface layer of Sn or Sn alloy. From the viewpoint of improving the ISS cycle characteristics, the surface layer is preferably formed of an alloy containing 50 mass% or more of Sn. The surface layer is more preferably made of Sn from the viewpoint of further improving the ISS cycle characteristics. Since the surface layer is made of Sn or Sn alloy, it is possible to provide a lead acid battery having a long life performance that does not suddenly reach a life under PSOC.

Since the surface layer is made of Sn or Sn alloy, it is possible to provide a lead-acid battery having a long-life performance that does not suddenly reach a life under PSOC, because a charge/discharge cycle for ISS vehicle applications and the like is provided. It is presumed that this is because when the above is repeated, the ears are less likely to break in the negative electrode current collector. Although the cause of the ear breakage is not clear, it is considered that the ear breakage is likely to occur due to the formation of lead sulfate in the ear and repeated dissolution and precipitation of the lead sulfate. Therefore, it is considered that the rupture of the ears is less likely to occur when the surface where the ears and the electrolytic solution contact each other has a potential higher than the potential at which the dissolution and precipitation of lead sulfate is repeated.

If the surface layer is made of Sn or a Sn alloy, even if it contains a metal other than Pb and Sn, it is less likely to cause the ear to break and the ISS cycle characteristics are improved.

In the present invention, the surface layer may be formed on the ear portion, and the surface layer may be formed on the upper frame portion.

Examples of the method of forming the surface layer on the ears include a rolling method and a hot dipping method. The rolling method is a method in which a material for forming a surface layer (for example, a metal plate or an alloy plate) and a material for forming a surface layer (a metal sheet or an alloy sheet) are superposed and rolled. .. On the other hand, the hot-dip plating method is a method in which the ears are immersed in a molten bath in which the material forming the surface layer has been melted for plating. Of these methods, the rolling method is preferred in the present invention.

The method of forming the surface layer by the rolling method may be, for example, the following method. An Sn sheet for forming a surface layer or an alloy sheet containing Sn is superposed on both surfaces of a plate-shaped lead alloy (base material) and rolled by a rolling roller to produce a rolled sheet (making a rolled sheet. Process). Next, the rolled sheet is expanded by an expanding machine (expanding method) while adjusting the position of the rolled sheet so that the surface layer is formed at the position of the ear portion of the negative electrode current collector (expanding method), and the surface is placed at the position of the ear portion. A negative electrode current collector having a layer is obtained. In this rolling method, the thickness of the surface layer can be easily adjusted by adjusting the thickness of the alloy serving as the base material, the thickness of the sheet serving as the surface layer, or the thickness of the sheet after rolling. From the viewpoint of manufacturing, the thickness of the surface layer after rolling is preferably 10 μm or more and 60 μm or less.

In the electrode manufacturing process, for example, aging and drying are performed after the electrode material paste (positive electrode material paste and negative electrode material paste) is filled in a current collector (for example, a current collector grid such as a cast grid body or an expanded grid body). As a result, an unformed electrode 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 the raw material (lead powder or the like) of the negative electrode active material and (A) bisphenol resin, and may further contain (B) other additives.

The positive electrode material paste can be obtained, for example, by the following method. First, an additive (reinforcing short fibers, etc.) and water are added to the raw material of the positive electrode active material. Next, dilute sulfuric acid is added and then kneaded to obtain a positive electrode material paste. In producing the positive electrode material paste, lead tin (Pb ₃ O ₄ ) may be used as a raw material of the positive electrode active material from the viewpoint of shortening the formation time. An unformed positive electrode can be obtained by filling the current collector with this positive electrode material paste and then aging and drying.

When the reinforcing short fibers are used in the positive electrode material paste, the content of the reinforcing short fibers is preferably 0.005 to 0.3% by mass, based on the total mass of the raw materials (lead powder etc.) of the positive electrode active material, 0.05 to 0.3 mass% is more preferable.

The maturing conditions for obtaining the unformed positive electrode are preferably 15 to 60 hours in an atmosphere of a temperature of 35 to 85° C. and a humidity of 50 to 98 RH%. The drying conditions are preferably 45 to 80° C. for 15 to 30 hours.

The negative electrode material paste can be obtained, for example, by the following method. First, an additive (a resin having a sulfone group and/or a sulfonate group, reinforcing short fibers, barium sulfate, etc.) is added to the raw material of the negative electrode active material and dry-mixed to obtain a mixture. Then, a negative electrode material paste is obtained by adding sulfuric acid (dilute sulfuric acid or the like) and a solvent (water such as ion-exchanged water or an organic solvent) to this mixture and kneading. An unformed negative electrode can be obtained by filling the negative electrode material paste in a current collector (for example, a current collector grid such as a cast grid body or an expanded grid body) and then aging and drying.

When a resin having a sulfone group and/or a sulfonate group (such as a bisphenol resin), a carbon material, a reinforcing short fiber or barium sulfate is used in the negative electrode material paste, the blending amount of each component is preferably within the following range. The blending amount of the resin having a sulfo group and/or a sulfonate group is preferably 0.01 to 2.0 mass% in terms of resin solid content based on the total mass of the raw materials (lead powder etc.) of the negative electrode active material. , 0.05 to 1.0 mass% is more preferable, 0.1 to 0.5 mass% is further preferable, and 0.1 to 0.3 mass% is particularly preferable. The blending amount of the carbon material is preferably 0.1 to 3% by mass, more preferably 0.2 to 1.4% by mass, based on the total mass of the raw materials (lead powder or the like) of the negative electrode active material. The content of the reinforcing short fibers is preferably 0.05 to 0.15 mass% based on the total mass of the raw material (lead powder or the like) of the negative electrode active material. The blending amount of barium sulfate is preferably 0.01 to 2.0% by mass, more preferably 0.01 to 1.0% by mass, based on the total mass of the raw material (lead powder or the like) of the negative electrode active material.

As the aging conditions for obtaining the unformed negative electrode, it is preferable that the temperature is 45 to 65° C. and the humidity is 70 to 98 RH% for 15 to 30 hours. The drying conditions are preferably 45 to 60° C. for 15 to 30 hours.

In the assembly step, for example, the unformed negative electrodes and positive electrodes produced as described above are alternately laminated with separators interposed therebetween, and polar plates having the same polarity are connected to a strap (welding, etc.) to obtain a polar plate group. .. This electrode plate group is placed in a battery case to produce an unformed battery. Next, a lead acid battery is obtained by injecting dilute sulfuric acid into the unformed battery and then applying a direct current to carry out the formation. Usually, a lead acid battery having a predetermined specific gravity can be obtained by only energizing, but for the purpose of shortening the energizing time, dilute sulfuric acid may be removed once after the chemical conversion, and then the electrolytic solution may be injected.

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

Hereinafter, the present invention will be specifically described with reference to examples. However, the present invention is not limited to the following examples.

[Synthesis example 1]
<Preparation of bisphenol resin>
[Synthesis example (bisphenol/aminobenzenesulfonic acid/formaldehyde condensate)]
After adding 4.2 parts by mass (0.105 mol) of sodium hydroxide and 79.26 parts by mass (4.4 mol) of ion-exchanged water to a 500 mL separable flask equipped with a Dimroth, a mechanical stirrer and a thermometer, 150 rpm (= (min ⁻¹ ) and stirred for 5 minutes to prepare an aqueous sodium hydroxide solution. 17.32 parts by mass (0.1 mol) of 4-aminobenzenesulfonic acid was added to this aqueous sodium hydroxide solution, and the mixture was stirred at 25° C. for 30 minutes to obtain a uniform aqueous solution. To this aqueous solution, 9.09 parts by mass of paraformaldehyde (in terms of formaldehyde, 0.3 mol, manufactured by Mitsui Chemicals, Inc.) was added, and the mixture was stirred for 5 minutes to dissolve paraformaldehyde and obtain a uniform aqueous solution. After adding 21.92 parts by mass (0.096 mol) of bisphenol A and 1.04 parts by mass (0.004 mol) of bisphenol S to this aqueous solution, the solution was stirred for 10 hours while heating using an oil bath set at 90°C. Got As a result of measuring the pH of the aqueous solution at the start of the reaction immediately after the addition of bisphenol A and bisphenol S under the following measurement conditions, the pH was 8.6.

After the obtained aqueous solution was transferred to a heat-resistant container, the aqueous solution was put into a vacuum dryer set at 60°C. Next, a bisphenol-based resin powder (bisphenol/aminobenzenesulfonic acid/formaldehyde condensate) was obtained by drying for 10 hours under a reduced pressure of 1 kPa or less. The weight average molecular weight of the bisphenol resin obtained in Synthesis Example 1 was measured by GPC under the following conditions. As a result, the weight average molecular weight was 53900.

(PH measurement conditions)
Testing machine: Twin pH (manufactured by As One Co., Ltd.)
Calibration solution: pH 6.86 (25°C), pH 4.01 (25°C)
Measurement temperature: 25°C
Measurement procedure: Two-point calibration was performed using a calibration solution. After washing the sensor part of the tester, the measurement solution was sucked with a dropper, and 0.1 to 0.3 mL was dropped on the sensor part. The pH when the display of the end of measurement appeared on the screen was taken as the measured value.

(GPC condition)
Device: High Performance Liquid Chromatograph LC-2200 Plus (manufactured by JASCO Corporation)
Pump: PU-2080
Differential Refractometer: RI-2031
Detector: UV-visible absorption 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) 0.06×10 ² ; manufactured by Kishida Chemical Co., Ltd.), dibutylhydroxytoluene (molecular weight: 2.20×10 ² ; manufactured by Kishida Chemical Co., Ltd.)

<Preparation of lead acid battery>
[Example 1]
(Preparation of positive electrode plate)
Lead powder and lead tin (Pb ₃ O ₄ ) were used as raw materials for the positive electrode active material. The raw material of the positive electrode active material, 0.07 mass% of reinforcing short fibers (acrylic fiber) based on the total mass of the raw material of the positive electrode active material, and water were added and kneaded. Subsequently, a positive electrode active material paste was prepared by kneading while adding dilute sulfuric acid having a specific gravity of 1.280 (20° C. conversion, the same applies hereinafter) little by little. The positive electrode active material paste was filled in an expanded type current collector prepared by subjecting a rolled sheet made of a lead alloy to an expanding process, and then aged for 24 hours in an atmosphere of 50° C. and a humidity of 98%. Then, it dried and produced the unformed positive electrode plate.

(Preparation of negative electrode current collector)
A negative electrode current collector was produced as follows. A plate-shaped lead-0.05 mass% calcium-0.5 mass% tin alloy having a thickness of 12 mm was used as the base material of the negative electrode current collector. A Sn sheet having a thickness of 0.2 mm was used as the metal sheet for forming the surface layer. Sn sheets were superposed on both surfaces of the lead-0.05 mass% calcium-0.5 mass% tin alloy and rolled with rolling rollers to produce a rolled sheet having a thickness of 0.9 mm. The thickness of the surface layer formed on the rolled sheet was about 15 μm.

While adjusting the position of the rolled sheet so that the Sn layer is provided at the position of the ears of the negative electrode current collector, the rolled sheet is unfolded by a reciprocating expander, and the negative electrode current collector having the Sn layer at the ears is formed. Was produced.

(Preparation of negative electrode plate)
Lead powder was used as a raw material of the negative electrode active material. 0.2% by mass of bisphenol resin prepared in Synthesis Example 1, 0.1% by mass of reinforcing short fibers (acrylic fibers), 1.0% by mass of barium sulfate, and 0.2 carbonaceous conductive material (furnace black). A mass% mixture was added to the lead powder and then dry mixed (the compounding amount is a compounding amount based on the total mass of the raw materials of the negative electrode active material). Next, after adding water, the mixture was kneaded. Subsequently, a negative electrode active material paste was prepared by kneading while adding dilute sulfuric acid having a specific gravity of 1.280 little by little. The current collector prepared by the above method was filled with this negative electrode active material paste and then aged in an atmosphere of 50° C. and a humidity of 98% for 24 hours. Then, it dried and produced the unformed negative electrode plate.

(Battery assembly)
The unformed negative electrode plate was inserted into a bag-shaped polyethylene separator. Next, eight unformed positive electrode plates and nine unformed negative electrode plates inserted in the bag-shaped separator were alternately laminated. Then, a cast-on-strap (COS) method was used to weld the ears of the polar plates having the same polarity to each other to prepare a polar plate group. The electrode plate group was inserted into a battery case to assemble a 2V single cell battery (corresponding to a D26 size single cell according to JIS D 5301). Dilute sulfuric acid having a specific gravity of 1.280 was poured into this battery. Then, the lead storage battery was obtained by chemical formation in a water tank at 35° C. for 20 hours at a current of 20 A.

[Examples 2 to 4, Comparative Examples 1 to 4]
Examples 2 and 3 are the same as Examples 2 and 3, except that dilute sulfuric acid having a specific gravity of 1.280 in which anhydrous aluminum sulfate was dissolved so that aluminum ions in the electrolytic solution had the concentrations shown in Table 1 was injected into this battery. A lead acid battery was produced in the same manner as in 1. Further, in Example 4, a lead storage battery was prepared in the same manner as in Example 3, except that the surface layer provided on the negative electrode current collector used for the negative electrode plate was changed to a Pb-Sn (50 mass%) alloy layer. .. In Comparative Example 2, a lead acid battery was produced in the same manner as in Example 1 except that a commercially available sodium ligninsulfonate (trade name: Vanillex N, manufactured by Nippon Paper Industries Co., Ltd.) was used instead of the bisphenol resin. Comparative Example 3 was the same as Example 1 except that the surface layer was not formed and a commercially available sodium ligninsulfonate (trade name: Vanillex N, manufactured by Nippon Paper Industries Co., Ltd.) was used instead of the bisphenol resin. A lead acid battery was produced. In Comparative Example 4, a lead storage battery was produced in the same manner as in Example 1 except that the surface layer was not formed.

<Evaluation of battery characteristics>
With respect to the lead acid battery described above, charge acceptability, low temperature high rate discharge performance and ISS cycle characteristics were measured as follows. Regarding the charge acceptability, the low temperature high rate discharge performance and the ISS cycle characteristics, relative measurement was performed by setting the measurement result of Comparative Example 3 to 100. The results are shown in Table 1.

(Charge acceptability)
The manufactured battery was subjected to constant current discharge at 25° C. and 10.4 A for 30 minutes, left for 12 hours, and then constant voltage charged at 2.41 V for 60 seconds under a limiting current of 100 A, and 5 seconds after the start of charging. Was measured.

(Low temperature high rate discharge performance)
In the manufactured battery, the battery temperature was adjusted to −15° C., constant current discharge was performed at 300 A, and the discharge duration until the cell voltage fell below 1.0 V was measured.

(ISS cycle characteristics)
The ISS cycle evaluation was performed as follows. The atmosphere temperature was adjusted so that the battery temperature was 25° C., constant current discharge was performed for 45A-59 seconds and 300A-1 second, and then 100A-2.33V-60 second constant current/constant voltage charge was performed for 1 hour. A cycle test was conducted. During the test, the cycle was restarted after leaving for 40 hours every 3600 cycles. This test is a cycle test that simulates the usage of lead acid batteries in ISS vehicles. In this cycle test, since the charge amount is smaller than the discharge amount, the charge gradually becomes insufficient unless the charge is completely performed. As a result, the voltage at the first second when the discharge current is set to 300 A and the voltage is discharged for 1 second is Gradually decreases. That is, when the negative electrode is polarized during constant current/constant voltage charging and switched to constant voltage charging at an early stage, the charging current is attenuated and charging becomes insufficient. In this life test, when the voltage at the first second at 300 A discharge fell below 1.2 V, the life of the battery was determined.

In Example 1 in which the negative electrode material contains bisphenol-based resin and the negative electrode current collector has a surface layer, the negative electrode material contains bisphenol-based resin, but the negative electrode current collector has a surface layer. Larger ISS cycle characteristics than Comparative Example 1 which does not have it and Comparative Example 2 which has a surface layer on the ears of the negative electrode current collector but contains sodium lignin sulfonate that is not a bisphenol resin as the negative electrode material. You can see that it will improve. The reason for this is that the formation of Sn or Sn alloy as the surface layer and the inclusion of bisphenol-based resin in the negative electrode material cause the potential of the ears to change to a potential higher than the dissolution/precipitation potential of lead sulfate. It is presumed that the ISS cycle characteristics could be further improved because the corrosion and fracture of the parts were suppressed.

In addition, it can be seen from Examples 2 and 3 that the charge acceptance and the ISS cycle characteristics are further improved by including aluminum ions in the electrolytic solution.

Claims (7)

A positive electrode, a negative electrode, and an electrolytic solution are provided, the negative electrode has a negative electrode material and a negative electrode current collector, the negative electrode material contains a bisphenol-based resin and a negative electrode active material, and the negative electrode current collector has an ear portion. A method for producing a lead storage battery (excluding one in which the negative electrode material contains alginic acid or a salt thereof) , wherein the ear has a surface layer of Sn or Sn alloy formed thereon.
Comprising a step of preparing the negative electrode current collector,
Manufacture of a lead storage battery, wherein the step of preparing the negative electrode current collector includes the step of preparing a base material and the step of forming a layer made of Sn or a Sn alloy to be the surface layer on the base material. Method. The step of forming a layer made of Sn or a Sn alloy includes a step of superimposing an Sn sheet or an alloy sheet containing Sn for forming the surface layer on both surfaces of the base material, and rolling with a rolling roller. The method for manufacturing the lead storage battery according to claim 1. The method for manufacturing a lead storage battery according to claim 2, wherein the step of forming the layer made of Sn or the Sn alloy further includes a step of expanding the rolled sheet obtained in the rolling step by an expanding method. The method for manufacturing a lead storage battery according to claim 1, wherein the step of forming a layer made of Sn or an Sn alloy is a step of hot-dip-plating Sn or a Sn alloy on a portion of the base material to be the ear portion. The method for manufacturing a lead storage battery according to claim 1, wherein the lead storage battery is a lead storage battery used under a partially charged state. The method for producing a lead storage battery according to claim 1, wherein the lead storage battery is a lead storage battery for an idling stop system vehicle. The method for manufacturing a lead storage battery according to claim 1, wherein the lead storage battery is a lead storage battery for a micro hybrid vehicle.