JP6361513B2 - Lead acid battery - Google Patents

Description

  The present invention relates to a lead-acid battery.

  In recent years, various measures for improving fuel efficiency have been studied for automobiles in order to prevent air pollution or global warming. Examples of automobiles with measures to improve fuel efficiency include micro-hybrid vehicles such as idling stop vehicles (hereinafter referred to as “ISS vehicles”) that reduce engine operation time, and power generation control vehicles that reduce alternator power generation by engine power. Is being considered.

  In an ISS vehicle, the number of engine starts increases, so that a large current discharge of the lead storage battery is repeated. Further, in the ISS car and the power generation control car, the amount of power generated by the alternator is reduced, and the lead storage battery is charged intermittently, so that the charge is insufficient.

  The lead storage battery which is 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.

  In recent years, in Europe, the charge performance of lead-acid batteries during charge / discharge cycles in accordance with the control of micro-hybrid vehicles has been emphasized, and DCA (Dynamic Charge Acceptance) evaluation in this form is being standardized. is there. That is, in lead storage batteries used in PSOC, improvement in charge acceptance is required.

  A lead storage battery has, for example, a structure in which a positive electrode (a positive electrode plate or the like), a negative electrode (a negative electrode plate or the like), and a synthetic resin separator that separates both electrodes are stacked. As one of the techniques for improving the charge acceptability, it is conceivable to reduce the charge transfer resistance by reducing the thickness of the separator.

  By the way, generally, when charging in a lead storage battery, oxygen gas is generated from the positive electrode, and the surface of the separator facing the positive electrode is in an oxidizing atmosphere. Therefore, the surface of the separator that faces the positive electrode is more easily oxidized than the surface that faces the negative electrode, and when a thin film separator is used, the separator deteriorates and becomes brittle, its thickness decreases, and there are holes. It becomes easy. As a result, a short circuit between the positive electrode and the negative electrode may be a problem.

  On the other hand, in Patent Document 1 below, in order to suppress a short circuit and improve life characteristics, a separator having a base portion with a thickness of 0.30 mm is formed with a linear rib on the surface of the separator, and the rib Is a technique for adjusting the ratio (D / T), where D is the height dimension and T is the thickness dimension (base part) of the separator.

JP 2003-338274 A

  However, in recent years, there has been a demand for further enhancing the short-circuit suppressing effect as compared with the conventional technique such as Patent Document 1 described above. Moreover, when the thickness of a separator is made thin, it is calculated | required to obtain the outstanding charge acceptance property, suppressing a short circuit.

  This invention is made | formed in view of the said situation, and it aims at providing the lead storage battery which can acquire the outstanding charge acceptance property, suppressing a short circuit.

  As a result of intensive studies by the present inventors, it has been found that it is difficult to obtain excellent charge acceptability while suppressing short circuits with the technique described in Patent Document 1. On the other hand, the present inventors in a lead storage battery comprising a positive electrode and a negative electrode facing each other via a separator having a convex rib and a base portion supporting the rib, and an electrolytic solution containing aluminum. It has been found that the above problem can be solved by adjusting the thickness of the base portion and the height of the rib so as to satisfy predetermined conditions.

  That is, the lead storage battery according to the present invention is a lead storage battery including a positive electrode and a negative electrode facing each other through a separator, and an electrolytic solution, wherein the separator supports a convex rib and a base portion that supports the rib. The thickness T of the base portion is 0.25 mm or less, the ratio H / T of the height H of the rib to the thickness T of the base portion is 2 to 6, and the electrolyte is aluminum. Contains ions.

  According to the lead storage battery of the present invention, excellent charge acceptability can be obtained while suppressing short circuit. Therefore, especially after the charge and discharge are repeated to some extent from the initial state and the active material is sufficiently activated, the SOC (State Of Charge), which tends to be low in ISS vehicles and micro hybrid vehicles, is maintained at an appropriate level. can do. Moreover, according to the lead acid battery which concerns on this invention, the outstanding charge acceptance property and other outstanding battery performances (a discharge characteristic, cycling characteristics, etc.) can be made compatible.

  Moreover, according to the lead acid battery which concerns on this invention, it can suppress that the lifetime of the lead acid battery used under PSOC becomes short. In addition, about the reason why the life of the lead-acid battery used under PSOC is shortened, if charging and discharging are repeated in a state where charging is insufficient, lead sulfate generated in the negative electrode (negative electrode plate, etc.) becomes coarse during discharge. This is thought to be because lead sulfate is difficult to return to the spongy metallic lead that is the charge product.

  The separator preferably includes a polyolefin. In this case, it is further excellent in short circuit suppression, and charge acceptability, discharge characteristics, and cycle characteristics can be improved in a well-balanced manner.

  The concentration of the aluminum ions is preferably 0.001 to 0.1 mol / L. In this case, charge acceptability and discharge characteristics can be improved with a good balance.

  According to the lead storage battery of the present invention, excellent charge acceptability can be obtained while suppressing short circuit. Moreover, according to the lead acid battery which concerns on this invention, the outstanding charge acceptance property and other outstanding battery performances (a discharge characteristic, cycling characteristics, etc.) can be made compatible. The lead acid battery according to the present invention can be suitably used in a micro hybrid vehicle such as an ISS car as a liquid lead acid battery in which charging is intermittently performed and high rate discharge is performed under PSOC. ADVANTAGE OF THE INVENTION According to this invention, the application to the micro hybrid vehicle of a lead storage battery can be provided. ADVANTAGE OF THE INVENTION According to this invention, the application to the ISS vehicle of a lead storage battery can be provided.

It is drawing which shows a separator. It is sectional drawing of a separator and an electrode. It is a figure which shows the electrode accommodated in a bag separator and a bag separator.

  Hereinafter, embodiments of the present invention will be described in detail. In addition, since specific gravity changes with temperature, in this specification, it defines as specific gravity converted at 20 degreeC.

<Lead battery>
The lead storage battery according to the present embodiment includes, for example, a battery case, an electrode (electrode plate or the like), an electrolytic solution (sulfuric acid or the like), and a separator. The electrode and the electrolytic solution are accommodated in the battery case. The electrode has a positive electrode (such as a positive electrode plate) and a negative electrode (such as a negative electrode plate) that face each other with a separator interposed therebetween. 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 positive electrode and the negative electrode constitute, for example, an electrode group (electrode plate group or the like) by being laminated via a separator. 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 the present embodiment, the positive electrode material and the negative electrode material are, for example, electrode materials after chemical conversion. When the electrode material is unformed, the electrode materials (unformed positive electrode material and unformed negative electrode material) contain the raw materials and the like. The current collector constitutes a conductive path for current from the electrode material. As a basic configuration of the lead storage battery, the same configuration as that of a conventional lead storage battery can be used.

  Fig.1 (a) is a front view which shows a separator, FIG.1 (b) is sectional drawing of a separator. FIG. 2 is a cross-sectional view of the separator and the electrode. As shown in FIG. 1, the separator 10 includes a flat base portion 11, a plurality of convex (for example, linear) ribs 12, and mini-ribs 13. The base portion 11 supports the rib 12 and the mini rib 13. The ribs 12 are arranged substantially parallel to each other on the one surface 10 a of the separator 10. The interval between the ribs 12 is, for example, 3 to 15 mm. One end in the height direction of the rib 12 is integrally connected to the base portion 11, and the other end in the height direction of the rib 12 is in contact with one electrode 14a of the positive electrode and the negative electrode (see FIG. 2). ). The base portion 11 faces the electrode 14 a in the height direction of the rib 12. Ribs are not disposed on the other surface 10b of the separator 10, and the other surface 10b of the separator 10 faces or is in contact with the other electrode 14b (see FIG. 2) of the positive electrode and the negative electrode.

  A large number of the mini-ribs 13 are formed on both sides of the separator 10 in the width direction so as to extend in the longitudinal direction of the separator 10. The mini-rib 13 has a function of improving the separator strength in order to prevent the corners of the electrodes from breaking through the separator when the lead storage battery vibrates in the lateral direction. Note that the height, width, and interval of the mini-ribs 13 are preferably smaller than the ribs 12. Further, the cross-sectional shape of the mini-rib 13 may be the same as or different from that of the rib 12. The cross-sectional shape of the mini-rib 13 is preferably a semicircular shape. Moreover, the minirib 13 does not need to be formed.

  FIG. 3 is a diagram showing a state in which the bag separator 20 and the electrode (for example, the negative electrode) 14 accommodated in the bag separator 20 are inserted. As shown to Fig.1 (a), the separator 10 used for preparation of the bag separator 20 is formed in the elongate sheet form, for example. The bag separator 20 is obtained by cutting the separator 10 into an appropriate length, folding it in the longitudinal direction of the separator 10 and arranging the electrodes 14 on the inside thereof, and then mechanically sealing, crimping, or heat-welding both sides ( For example, reference numeral 22 in FIG. 3 is a mechanical seal portion). Thereby, the bag separator 20 shown in FIG. 3 is obtained.

  The upper limit of the thickness T of the base part 11 is 0.25 mm or less from the viewpoint of obtaining excellent charge acceptability and discharge characteristics. When thickness T exceeds 0.25 mm, there exists a tendency for charge acceptance and a discharge characteristic to fall. The upper limit of the thickness T of the base portion 11 is preferably 0.2 mm or less, and more preferably 0.15 mm or less, from the viewpoint of obtaining further excellent charge acceptance and discharge characteristics. The lower limit of the thickness T of the base portion 11 is not particularly limited, but is preferably 0.05 mm or more and more preferably 0.1 mm or more from the viewpoint of easily suppressing a short circuit.

  The upper limit of the height of the rib 12 (the height in the facing direction of the base portion 11 and the electrode 14) H is preferably 1.25 mm or less, more preferably 1.0 mm or less, from the viewpoint of obtaining further excellent charge acceptance. More preferably, it is 0.75 mm or less. The lower limit of the height H of the rib 12 is preferably 0.3 mm or more, more preferably 0.4 mm or more, and still more preferably 0.5 mm or more, from the viewpoint of suppressing oxidative deterioration at the positive electrode.

The lower limit of the ratio H / T of the height H of the rib 12 to the thickness T of the base part 11 is 2 or more from the viewpoint of excellent oxidation resistance of the separator. When the ratio H / T is 2 or more, a portion that does not contact the electrode (for example, the positive electrode) can be sufficiently secured, so that it is estimated that the oxidation resistance of the separator is improved.
The lower limit of the ratio H / T is preferably 2.4 or more, and more preferably 3 or more, from the viewpoint of further improving the oxidation resistance and productivity of the separator. The upper limit of the ratio H / T is 6 or less from the viewpoint of excellent rib shape retention and the suppression of short circuits. If the ratio H / T is 6 or less, the distance between the positive and negative electrodes is sufficient, and it is estimated that short-circuiting is suppressed. Further, when the ratio H / T is 6 or less, it is presumed that the battery characteristics such as charge acceptability are favorably maintained without damaging the ribs when the lead storage battery is assembled. The upper limit of the ratio H / T is preferably 5 or less, more preferably 4.5 or less, and still more preferably 4 or less, from the viewpoint of easily suppressing a short circuit and the viewpoint of further excellent rib shape retention.

  Further, the upper base width B (see FIG. 1B) of the rib 12 is preferably 0.1 to 2 mm, more preferably 0.2 to 1 mm, from the viewpoint of excellent rib shape retention and oxidation resistance. 0.2-0.8 mm is still more preferable. The lower bottom width A of the rib is preferably 0.2 to 4 mm, more preferably 0.3 to 2 mm, and still more preferably 0.4 to 1 mm, from the viewpoint of excellent shape retention of the rib. The ratio of the upper base width B to the lower base width A (B / A) is preferably 0.1 to 1, more preferably 0.2 to 0.8, from the viewpoint of excellent rib shape retention. -0.6 is still more preferable.

  The separator is preferably in the form of a bag that encloses at least one of a positive electrode and a negative electrode. For example, a mode in which one of the positive electrode and the negative electrode is accommodated in a bag-shaped separator and is alternately laminated with the other of the positive electrode and the negative electrode is preferable. For example, when a bag-shaped separator is applied to the positive electrode, it is preferable that the negative electrode is accommodated in the bag-shaped separator because there is a possibility of passing through the separator due to the elongation of the positive electrode current collector.

  The separator used for the lead storage battery (liquid lead storage battery, etc.) is not particularly limited as long as it prevents electrical connection between the positive electrode and the negative electrode and allows the sulfate ions of the electrolytic solution to pass through. Specific examples include a microporous synthetic resin sheet, a glass fiber bonded to acid-resistant paper, and the like. The separator made of a microporous synthetic resin sheet preferably contains a polyolefin (polyethylene or the like). In the process of laminating electrodes (electrode plates, etc.), the separator is cut in two along with the length of the negative electrode (negative electrode plate, etc.), and wraps the negative electrode by crimping both sides of the separator. Preferably there is.

  The electrolytic solution contains aluminum ions from the viewpoint of suppressing a short circuit. When the electrolytic solution contains aluminum ions, aluminum is precipitated on the surface layer portion of the separator, so that it is presumed that a short circuit can be suppressed because precipitation of lead is suppressed.

(Positive electrode material)
[Positive electrode active material]
The positive electrode material contains a positive electrode active material. The positive electrode active material can be obtained by chemical conversion after obtaining an unformed active material by aging and drying a positive electrode material paste containing a raw material of the positive electrode active material. The positive electrode active material after the formation preferably contains β-lead dioxide (β-PbO ₂ ), and may further contain α-lead dioxide (α-PbO ₂ ).
There is no restriction | limiting in particular as a raw material of a positive electrode active material, For example, lead powder is mentioned. As the lead powder, for example, lead powder manufactured by a ball mill type lead powder manufacturing machine or a barton pot type lead powder manufacturing machine (in the ball mill type lead powder manufacturing machine, a mixture of powder of main component PbO and scale-like metal lead) ). Red lead as a raw material of the positive electrode active material _(Pb 3 _{O 4)} may be used. The unformed positive electrode material preferably contains an unformed positive electrode active material containing tribasic lead sulfate as a main component.

  The average particle diameter of the positive electrode active material is preferably 0.3 μm or more, more preferably 0.5 μm or more, and even more preferably 0.7 μm or more, from the viewpoint of further improving charge acceptance and cycle characteristics. The average particle diameter of the positive electrode active material is preferably 2.5 μm or less, more preferably 2 μm or less, and even more preferably 1.5 μm or less from the viewpoint of further improving the cycle characteristics. The average particle diameter of the positive electrode active material is an average particle diameter of the positive electrode active material in the positive electrode material after chemical conversion. The average particle diameter of the positive electrode active material is, for example, the long side length of the active material particles in an image of a scanning electron micrograph (1000 times) in the range of 10 μm in length × 10 μm in the positive electrode material in the center of the positive electrode after chemical conversion It can be obtained as a numerical value obtained by arithmetically averaging the value of (maximum particle size).

  The content of the positive electrode active material is preferably 95% by mass or more based on the total mass of the positive electrode material from the viewpoint of further excellent battery characteristics (capacity, low-temperature high-rate discharge performance, charge acceptance, cycle characteristics, etc.), 97 The mass% or more is more preferable, and 99 mass% or more is still more preferable.

[Positive electrode additive]
The positive electrode material may further contain an additive. Examples of the additive include carbon materials (carbonaceous conductive materials), reinforcing short fibers, and the like. 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, and carbon fibers.

[Physical properties of positive electrode material]
The lower limit of the specific surface area of the positive electrode material is preferably 3 m ² / g or more, more preferably 4 m ² / g or more, and still more preferably 5 m ² / g or more from the viewpoint of further excellent charge acceptance. The upper limit of the specific surface area of the cathode material is not particularly limited, from the viewpoint of excellent practical point of view and utilization, preferably ^{15 m} 2 / g or less, more preferably ^13m 2 / g or less, is ^12m 2 / g or less Further preferred. The specific surface area of the positive electrode material is the specific surface area of the positive electrode material after chemical conversion. The specific surface area of the positive electrode material is, for example, a method of adjusting the amount of sulfuric acid and water added when preparing the positive electrode material paste, a method of refining the active material at the stage of the unformed active material, a method of changing the conversion conditions, etc. Can be adjusted.

  The specific surface area of the positive electrode material can be measured by, for example, the BET method. The BET method is a method in which an inert gas (for example, nitrogen gas) having a known molecular size is adsorbed on the surface of a measurement sample, and the surface area is obtained from the adsorption amount and the area occupied by the inert gas. This is a general method for measuring the surface area. Specifically, it is measured based on the following BET equation.

Relationship of the following formula (1), _P / P _o is established well in the range of 0.05 to 0.35. In addition, in Formula (1), the detail of each code | symbol is as follows.
P: Adsorption equilibrium pressure when in an adsorption equilibrium state at a constant temperature P _o : Saturated vapor pressure at the adsorption temperature V: Adsorption amount at the adsorption equilibrium pressure P V _m : Monomolecular layer adsorption amount (a gas molecule is a single molecule on a solid surface) Adsorption amount when layer is formed)
C: BET constant (parameter relating to the interaction between the solid surface and the adsorbent)

By transforming equation (1) (dividing the numerator denominator on the left side by P), the following equation (2) is obtained. In the specific surface area meter used for the measurement, gas molecules having a known adsorption occupation area are adsorbed on the sample, and the relationship between the adsorption amount (V) and the relative pressure (P / P _o ) is measured. From the measured V and P / _Po , the left side of Equation (2) and P / _Po are plotted. Here, assuming that the gradient is s, the following formula (3) is derived from the formula (2). Assuming that the intercept is i, the intercept i and the gradient s are as shown in the following formula (4) and the following formula (5), respectively.

When Expression (4) and Expression (5) are modified, the following Expression (6) and Expression (7) are obtained, respectively, and the following Expression (8) for obtaining the monomolecular layer adsorption amount V _m is obtained. That is, when the adsorption amount V at a certain relative pressure P / _Po is measured at several points and the slope and intercept of the plot are obtained, the monomolecular layer adsorption amount V _m is obtained.

The total surface area S _total (m ² ) of the sample is obtained by the following formula (9), and the specific surface area S (m ² / g) is obtained by the following formula (10) from the total surface area S _total . In the formula (9), N denotes the Avogadro's _{number, A CS} shows the adsorption cross sectional area ^{(m 2),} M indicates the molecular weight. Moreover, in Formula (10), w shows a sample amount (g).

  The porosity of the positive electrode material is preferably 50% or more, and more preferably 55% or more, from the viewpoint that the area where sulfuric acid enters the pores in the positive electrode material increases and the capacity tends to increase. Although there is no restriction | limiting in particular in the upper limit of the porosity of a positive electrode material, 70% or less is preferable from a viewpoint that the amount of sulfuric acid impregnation to the void | hole part in a positive electrode material is moderate, and can maintain the bonding force of active materials favorably. The upper limit of the porosity is more preferably 60% or less from a practical viewpoint. The porosity of the positive electrode material is the porosity of the positive electrode material after chemical conversion. The porosity of the positive electrode material is, for example, a value (ratio based on volume) obtained from mercury porosimeter measurement. The porosity of the positive electrode material can be adjusted by, for example, the amount of dilute sulfuric acid added when producing the positive electrode material paste.

(Negative electrode material)
[Negative electrode active material]
The negative electrode active material can be obtained by chemical conversion after obtaining an unformed active material by aging and drying a negative electrode material paste containing a raw material of the negative electrode active material. Examples of the negative electrode active material after chemical conversion include spongy lead. The spongy lead tends to react with sulfuric acid in the electrolyte 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 manufactured by a ball mill type lead powder manufacturing machine or a barton pot type lead powder manufacturing machine (in the ball mill type lead powder manufacturing machine, a mixture of powder of main component PbO and scale-like metal lead) ). The unformed negative electrode active material is composed of, for example, basic lead sulfate, metallic lead, and a lower oxide.

  The average particle diameter of the negative electrode active material is preferably 0.3 μm or more, more preferably 0.5 μm or more, and even more preferably 0.7 μm or more, from the viewpoint of further improving charge acceptance and cycle characteristics. The average particle diameter of the negative electrode active material is preferably 2.5 μm or less, more preferably 2 μm or less, and even more preferably 1.5 μm or less from the viewpoint of further improving cycle characteristics. The average particle diameter of the negative electrode active material is an average particle diameter of the negative electrode active material in the negative electrode material after chemical conversion. The average particle diameter of the negative electrode active material is, for example, the long side length of the active material particles in an image of a scanning electron micrograph (1000 times) in the range of 10 μm long × 10 μm wide in the negative electrode material at the center of the negative electrode after chemical conversion It can be obtained as a numerical value obtained by arithmetically averaging the value of (maximum particle size).

  The content of the negative electrode active material is preferably 93% by mass or more based on the total mass of the negative electrode material, from the viewpoint of further excellent battery characteristics (capacity, low-temperature high-rate discharge performance, charge acceptance, cycle characteristics, etc.), 95 More preferably, it is more preferably 98% by mass or more.

[Negative electrode additive]
The negative electrode material may further contain an additive. Examples of the additive include a resin (sulfone group and / or sulfone group) having at least one selected from the group consisting of a sulfone group (sulfonic acid group, sulfo group) and a sulfonate group (a group in which hydrogen of the sulfone group is substituted with an alkali metal). Or a resin having a sulfonate group); barium sulfate; a carbon material (carbonaceous conductive material); a reinforcing short fiber. When 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 charge acceptability can be further improved.

  Examples of the resin having a sulfone group and / or a sulfonate group include bisphenol resins, lignin sulfonic acid, and lignin sulfonate. Lignin sulfonic acid is a compound in which a part of the degradation product of lignin is sulfonated. Examples of the lignin sulfonate include potassium lignin sulfonate and sodium lignin sulfonate. Among these, bisphenol-based resins are preferable from the viewpoint of further improving charge acceptance.

  The bisphenol resin is selected from the group consisting of a bisphenol compound, at least one selected from the group consisting of aminoalkyl sulfonic acid, aminoalkyl sulfonic acid derivatives, aminoaryl sulfonic acid and aminoaryl sulfonic acid derivatives, and formaldehyde and formaldehyde derivatives. It is preferable that the resin is obtained by reacting at least one of the above.

  A bisphenol-based 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, 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-hydroxy Phenyl) diphenylmethane, 1,1-bis (4-hydroxyphenyl) cyclohexane, 1,1-bis (4-hydroxyphenyl) -3,3,5-trimethylcyclohexane, bis (4-hydroxyphenyl) sulfone (hereinafter “ Bisphenol S ").

Examples of aminoalkylsulfonic acid include aminomethanesulfonic acid, 2-aminoethanesulfonic acid, 3-aminopropanesulfonic acid, 2-methylaminoethanesulfonic acid and the like. Examples of the aminoalkylsulfonic acid derivative include a compound in which a hydrogen atom of aminoalkylsulfonic acid is substituted with an alkyl group (for example, an alkyl group having 1 to 5 carbon atoms) or the like, and a sulfone group of aminoalkylsulfonic acid (—SO ₃ H ) In which the hydrogen atom is substituted with an alkali metal (for example, sodium or potassium). Examples of aminoarylsulfonic acid include aminobenzenesulfone (4-aminobenzenesulfonic acid and the like), aminonaphthalenesulfone and the like. Examples of aminoarylsulfonic acid derivatives include compounds in which a hydrogen atom of aminoarylsulfonic acid is substituted with an alkyl group (for example, an alkyl group having 1 to 5 carbon atoms) or the like, a sulfone group of aminoarylsulfonic acid (—SO ₃ H) Examples include alkali metal salts in which a hydrogen atom is substituted with an alkali metal (for example, sodium or potassium).

  Examples of formaldehyde derivatives include paraformaldehyde, hexamethylenetetramine, and trioxane.

  The bisphenol-based resin preferably has at least one selected from the group consisting of a structural unit represented by the following formula (I) and a structural unit represented by the following formula (II).

［式（Ｉ）中、Ｘ^１は、２価の基を示し、Ａ^１は、炭素数１〜４のアルキレン基、又は、アリーレン基を示し、Ｒ^１１は、アルカリ金属又は水素原子を示し、Ｒ^１２は、メチロール基（−ＣＨ_２ＯＨ）を示し、Ｒ^１３及びＲ^１４は、それぞれ独立にアルカリ金属又は水素原子を示し、ｎ１１は、１〜６００の整数を示し、ｎ１２は、１〜３の整数を示し、ｎ１３は、０又は１を示す。］

[In Formula (I), X ¹ represents a divalent group, A ¹ represents an alkylene group having 1 to 4 carbon atoms, or an arylene group, R ¹¹ represents an alkali metal or a hydrogen atom, R ¹² represents a methylol group (—CH ₂ OH), R ¹³ and R ¹⁴ each independently represents an alkali metal or a hydrogen atom, n 11 represents an integer of 1 to 600, and n 12 represents 1 to 3 N13 represents 0 or 1. ]

［式（ＩＩ）中、Ｘ^２は、２価の基を示し、Ａ^２は、炭素数１〜４のアルキレン基、又は、アリーレン基を示し、Ｒ^２１は、アルカリ金属又は水素原子を示し、Ｒ^２２は、メチロール基（−ＣＨ_２ＯＨ）を示し、Ｒ^２３及びＲ^２４は、それぞれ独立にアルカリ金属又は水素原子を示し、ｎ２１は、１〜６００の整数を示し、ｎ２２は、１〜３の整数を示し、ｎ２３は、０又は１を示す。］

[In Formula (II), X ² represents a divalent group, A ² represents an alkylene group having 1 to 4 carbon atoms, or an arylene group, R ²¹ represents an alkali metal or a hydrogen atom, R ²² represents a methylol group (—CH ₂ OH), R ²³ and R ²⁴ each independently represents an alkali metal or a hydrogen atom, n 21 represents an integer of 1 to 600, and n ²² represents 1 to 3 N23 represents 0 or 1. ]

  The ratio of the structural unit represented by the formula (I) and the structural unit represented by the formula (II) 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 (I) and the structural unit represented by the formula (II) may be used.

X ¹ and X ² include, for example, alkylidene groups (methylidene group, ethylidene group, isopropylidene group, sec-butylidene group and the like), cycloalkylidene groups (cyclohexylidene group and the like), phenylalkylidene groups (diphenylmethylidene group, An organic group such as a phenylethylidene group; a sulfonyl group, and the isopropylidene group (—C (CH ₃ ) ₂ —) group is preferable from the viewpoint of further excellent charge acceptance, and from the viewpoint of further excellent discharge characteristics. A sulfonyl group (—SO ₂ —) is preferred. X ¹ and X ² may be substituted with a halogen atom such as a fluorine atom. When X ¹ and X ² are cycloalkylidene groups, the hydrocarbon ring may be substituted with an alkyl group or the like.

Examples of A ¹ and A ² 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 bivalent 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 of R ¹¹ , R ¹³ , R ¹⁴ , R ²¹ , R ²³ and R ²⁴ include sodium and potassium. n11 and n21 are preferably 5 to 300 from the viewpoint of further excellent cycle characteristics and solubility in a solvent. n12 and n22 are preferably 1 or 2, and more preferably 1, from the viewpoint of improving charge acceptability, discharge characteristics, and cycle characteristics in a well-balanced manner. n13 and n23 vary depending on the production conditions, but 0 is preferable from the viewpoint of further excellent cycle characteristics and excellent storage stability of the bisphenol-based resin.

  The weight average molecular weight of a resin having a sulfonic group and / or a sulfonic acid group (such as a bisphenol-based resin) suppresses the elution of a resin having a sulfonic group and / or a sulfonic acid group from an electrode to an electrolytic solution in a lead storage battery. Is preferably 3000 or more, more preferably 10,000 or more, still more preferably 20000 or more, and particularly preferably 30000 or more. The weight average molecular weight of the resin having a sulfone group and / or a sulfonate group is 200000 or less from the viewpoint that the cycle characteristics are easily improved by suppressing the adsorptivity to the electrode active material and the dispersibility. Is preferable, 150,000 or less is more preferable, and 100,000 or less is still more preferable.

The weight average molecular weight of the resin having a sulfone group and / or a sulfonate group 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.)

  When using a resin having a sulfone group and / or a sulfonate group, the content of the resin having a sulfone group and / or a sulfonate group is based on the total mass of the negative electrode material from the viewpoint of obtaining further excellent charge acceptability. Moreover, 0.01 mass% or more is preferable in conversion of solid content, 0.05 mass% or more is more preferable, and 0.1 mass% or more is still more preferable. The content of the resin having a sulfone group and / or a sulfonate group is preferably 2% by mass or less, preferably 1% by mass or less in terms of solid content, based on the total mass of the negative electrode material, from the viewpoint of obtaining further excellent discharge characteristics. Is more preferable, and 0.3 mass% or less is still more preferable.

  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, and carbon fibers.

[Physical properties of negative electrode material]
The specific surface area of the negative electrode material is preferably 0.4 m ² / g or more, more preferably 0.5 m ² / g or more, and 0.6 m ² / g or more from the viewpoint of increasing the reactivity between the electrolytic solution and the negative electrode active material. Is more preferable. The specific surface area of the negative electrode material, from the further suppression of the contraction of the negative electrode at the time of the cycle is preferably not more than ^2m 2 / g, more preferably not more than 1.8 m ² / g, more preferably not more than 1.5 m ² / g. The specific surface area of the negative electrode material is the specific surface area of the negative electrode material after chemical conversion. The specific surface area of the negative electrode material is, for example, a method of adjusting the amount of sulfuric acid and water added when preparing the negative electrode material paste, a method of refining the active material at the stage of the unformed active material, a method of changing the conversion conditions, etc. Can be adjusted. The specific surface area of the negative electrode material can be measured by, for example, the BET method.

(Current collector)
Examples of the method for producing the current collector include a casting method, an expanding method, and a punching method. Examples of the material of the current collector include a lead-calcium-tin alloy and a lead-antimony alloy. A small amount of selenium, silver, bismuth or the like can be added to these. For example, the current collector can be obtained by forming these materials into a lattice shape or a mesh shape by the above-described manufacturing method. The materials and manufacturing methods of the positive and negative electrode current collectors may be the same or different.

<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, an electrode material paste (a positive electrode material paste and a negative electrode material paste) is filled in a current collector (for example, a current collector such as a cast lattice body or an expanded lattice body) and then aged and dried. To obtain an unformed electrode. 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 preferably contains a raw material for the negative electrode active material (such as lead powder), and preferably contains a resin having a sulfone group and / or a sulfonate group (such as a bisphenol-based resin) as a dispersant. Further, other additives may be further contained.

The positive electrode material paste for obtaining the positive electrode material can be obtained, for example, by the following method. In producing the positive electrode material paste, lead (Pb ₃ O ₄ ) may be used as a raw material for the positive electrode active material from the viewpoint of shortening the chemical formation time.

  First, an additive (reinforcing short fiber or the like) is added to the raw material of the positive electrode active material and dry mixed to obtain a mixture. And a positive electrode material paste is obtained by adding and knead | mixing a sulfuric acid (dilute sulfuric acid etc.) and a solvent (water, such as ion-exchange water, an organic solvent) to this mixture.

  An unformed positive electrode can be obtained by filling the positive electrode material paste into a current collector (for example, a current collector such as a cast grid or an expanded grid) and then aging and drying.

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

  As aging conditions for obtaining an unchemically formed positive electrode, 15 to 60 hours are preferable 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. and 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, a reinforcing short fiber, barium sulfate, etc.) is added to the raw material of the negative electrode active material and dry mixed to obtain a mixture. And a negative electrode material paste is obtained by adding and knead | mixing a sulfuric acid (diluted sulfuric acid etc.) and a solvent (water, such as ion-exchange water, an organic solvent) to this mixture. An unformed negative electrode can be obtained by filling the negative electrode material paste into the current collector and then aging and drying.

  In the negative electrode material paste, 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, the blending amount of each component is preferably in the following range. The blending amount of the resin having a sulfonic group and / or a sulfonic acid group is preferably 0.01 to 2.0% by mass in terms of resin solid content, based on the total mass of the negative electrode active material (lead powder, etc.). 0.05-1.0 mass% is more preferable, 0.1-0.5 mass% is still more preferable, 0.1-0.3 mass% is especially 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 material (lead powder or the like) of the negative electrode active material. The compounding amount of the reinforcing short fibers is preferably 0.05 to 0.3% by mass based on the total mass of the negative electrode active material (lead powder or the like). The blending amount of barium sulfate is preferably 0.01 to 2.0 mass%, more preferably 0.01 to 1.0 mass%, based on the total mass of the raw material (lead powder or the like) of the negative electrode active material.

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

  In the assembling process, for example, the unformed negative electrode and the unformed positive electrode prepared as described above are alternately stacked via separators, and the current collectors of the same polarity electrodes are connected by a strap (welding or the like). An electrode group is obtained. This electrode group is arranged in a battery case to produce an unformed battery. Next, after injecting an electrolytic solution into the non-chemical cell, 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 electrolytic solution contains, for example, sulfuric acid and aluminum ions, and can be obtained 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 after the formation of the electrolytic solution (electrolytic solution containing aluminum ions) is preferably in the following range. The specific gravity of the electrolytic solution is preferably 1.25 or more, more preferably 1.26 or more, further preferably 1.27 or more, and 1.275 or more from the viewpoint of suppressing osmotic short-circuiting or freezing and further improving discharge characteristics. Particularly preferred. The specific gravity of the electrolytic solution is preferably 1.33 or less, more preferably 1.32 or less, still more preferably 1.31 or less, and particularly preferably 1.30 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 Industry Co., Ltd.

  The aluminum ion concentration of the electrolytic solution is preferably 0.001 mol / L or more, more preferably 0.003 mol / L or more, based on the total amount of the electrolytic solution, from the viewpoint of further improving charge acceptability and cycle characteristics. The aluminum ion concentration of the electrolytic solution is preferably 0.1 mol / L or less, more preferably 0.05 mol / L or less, based on the total amount of the electrolytic solution, from the viewpoint of further improving charge acceptance and cycle characteristics. 03 mol / L or less is more preferable. The aluminum ion concentration of the electrolytic solution can be measured by, for example, ICP emission spectroscopy (high frequency inductively coupled plasma emission spectroscopy).

  Although the details of the mechanism by which the charge acceptability is improved when the aluminum ion concentration of the electrolytic solution is in the predetermined range are not clear, it is estimated as follows. That is, when the aluminum ion concentration is within the predetermined range, the solubility of the crystalline lead sulfate, which is a discharge product, in the electrolytic solution increases under any low SOC, or due to the high ion conductivity of aluminum ions. This is presumably because the diffusibility of the electrolytic solution into the electrode active material is improved.

  The details of the mechanism by which the cycle characteristics are improved when the aluminum ion concentration of the electrolytic solution is in the predetermined range are not clear, but are estimated as follows. When aluminum ions are contained in the electrolytic solution, aluminum precipitates in the separator, particularly in the surface layer portion, so that precipitation of lead is suppressed in the separator and the precipitate is difficult to grow, so that an infiltration short circuit is suppressed. it is conceivable that.

  The battery case can accommodate an electrode (electrode plate or the like) inside. The battery case preferably has a box body whose upper surface is opened and a lid body that covers the upper surface of the box body from the viewpoint of easily accommodating the electrode. Note that an adhesive, heat welding, laser welding, ultrasonic welding, or the like can be appropriately used for bonding the box and the lid. The shape of the battery case is not particularly limited, but a rectangular shape is preferable so that an ineffective space is reduced when an electrode (a plate plate or the like) is accommodated.

  The material of the battery case is not particularly limited, but needs to be resistant to an electrolytic solution (such as dilute sulfuric acid). Specific examples of the battery case material include PP (polypropylene), PE (polyethylene), and ABS resin. When the material is PP, it is advantageous in terms of acid resistance, workability (difficult to heat weld the battery case and the lid with ABS resin), and cost.

  When the battery case is constituted by a box and a lid, the material of the box and the lid may be the same material or different from each other. Therefore, materials having the same thermal expansion coefficient are preferable.

  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 aging and drying in the electrode manufacturing process (tank chemical conversion).

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

<Synthesis of bisphenol resin>
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, mechanical stirrer and thermometer, 150 rpm (= The mixture was stirred for 5 minutes at min ⁻¹ ) to prepare an aqueous sodium hydroxide solution. After adding 17.32 parts by mass (0.1 mol) of 4-aminobenzenesulfonic acid to the aqueous sodium hydroxide solution, the mixture was stirred at 25 ° C. for 30 minutes to obtain a uniform solution A. After adding 9.09 parts by mass of paraformaldehyde (in terms of formaldehyde, 0.3 mol, manufactured by Mitsui Chemicals) to the solution A, the mixture was stirred for 5 minutes to dissolve the paraformaldehyde to obtain a uniform solution B. Next, 21.92 parts by mass (0.096 mol) of bisphenol A and 1.04 parts by mass (0.004 mol) of bisphenol S were added to the solution B, and then stirred for 10 hours while heating using an oil bath set at 90 ° C. Solution C was obtained.

As a result of measuring the pH of the solution immediately after adding bisphenol A and bisphenol S (at the start of the reaction) under the following measurement conditions, the pH was 8.6.
(PH measurement conditions)
Testing machine: Twin pH (manufactured by ASONE Corporation)
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 testing machine, the measurement solution was sucked with a dropper and 0.1 to 0.3 mL was dropped onto the sensor part. The pH at the end of measurement on the screen was taken as the measured value.

  Solution C prepared above was transferred to a heat-resistant container. The heat-resistant container containing the solution C is put into a vacuum dryer set at 60 ° C., and then dried for 10 hours under a reduced pressure of 1 kPa or less to obtain a bisphenol resin powder (bisphenol / aminobenzenesulfonic acid / formaldehyde condensate). Got. As a result of measuring the weight average molecular weight of the bisphenol resin by GPC under the following conditions, the weight average molecular weight was 53900.

{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.)

<Production of lead acid battery>
Example 1
[Production of positive electrode plate]
Lead powder and red lead (Pb ₃ O ₄ ) were used as raw materials for the positive electrode active material (lead powder: red lead = 96: 4 (mass ratio)). 0.07% by mass of reinforcing short fibers (acrylic fibers) based on the total mass of the positive electrode active material, the total mass of the positive electrode active material, and water were mixed and kneaded. Then, it knead | mixing, adding dilute sulfuric acid (specific gravity 1.280) little by little, and produced the positive electrode material paste. This positive electrode material paste was filled in an expanded lattice produced by subjecting a rolled sheet made of a lead alloy to an expanding process. Next, the positive electrode material paste was aged in an atmosphere of a temperature of 50 ° C. and a humidity of 98% for 24 hours. Then, it dried and produced the unchemically formed positive electrode plate.

[Production of negative electrode plate]
Lead powder was used as a raw material for the negative electrode active material. 0.2% by mass of resin (bisphenol-based resin) shown in Table 1 (in terms of solid content), 0.1% by mass of reinforcing short fibers (acrylic fibers), 1.0% by mass of barium sulfate, carbon material (furnace) A mixture containing 0.2% by mass of black) was added to the lead powder and then dry-mixed (the compounding amount is based on the total mass of the negative electrode active material). Next, the mixture was kneaded after adding water. Then, it knead | mixing, adding dilute sulfuric acid (specific gravity 1.280) little by little, and produced the negative electrode material paste. The negative electrode material paste was filled in an expanded lattice produced by subjecting a rolled sheet made of a lead alloy to an expanding process. Next, the negative electrode material paste was aged in an atmosphere of a temperature of 50 ° C. and a humidity of 98% for 24 hours. Then, it dried and produced the unchemically formed negative electrode plate.

[Battery assembly]
A polyethylene separator (base portion thickness T and rib height H is shown in Table 1) was processed into a bag shape and an unformed negative electrode plate was accommodated. A plurality of linear ribs (rib interval: 7.35 mm, rib upper base width: 0.4 mm, rib lower base width: 0.8 mm) are formed on one surface of the separator, and the ribs are formed on the positive electrode plate. Arranged to touch. Next, five unchemically formed positive electrode plates and six unchemically formed negative electrode plates accommodated in the bag-like separator were alternately laminated. Subsequently, the ears of the same polarity electrode plates were welded together by a cast on strap (COS) method to produce an electrode plate group. The electrode plate group was inserted into a battery case to assemble a 2V single cell battery (corresponding to a B19 size single cell defined in JIS 50301). Dilute sulfuric acid having a specific gravity of 1.280 in which aluminum sulfate anhydride was dissolved so that the aluminum ion concentration was 0.004 mol / L was injected into this battery. Then, it formed in a 50 degreeC water tank with the energizing current 10A for 16 hours, and obtained the lead acid battery.

[Specific surface area measurement]
A sample for measuring the specific surface area was prepared by the following procedure. First, the formed battery was disassembled, the electrode plates (positive electrode plate and negative electrode plate) were taken out, washed with water, and dried at 50 ° C. for 24 hours. Next, 2 g of an electrode material (a positive electrode material and a negative electrode material) was collected from the center of the electrode plate and dried at 130 ° C. for 30 minutes to prepare a measurement sample.

The specific surface areas of the positive electrode material and the negative electrode material after chemical conversion were calculated according to the BET method by measuring the nitrogen gas adsorption amount at a liquid nitrogen temperature by a multipoint method while cooling the measurement sample prepared above with liquid nitrogen. The measurement conditions were as follows. As a result of the measurement, the specific surface area of the positive electrode material was 5 m ² / g, and the specific surface area of the negative electrode material was 0.6 m ² / g.

{Measurement conditions for specific surface area}
Apparatus: HM-2201FS (manufactured by Macsorb)
Degassing time: 10 minutes at 130 ° C. Cooling: 4 minutes with liquid nitrogen Adsorbed gas flow rate: 25 mL / min

(Examples 2 to 10, Comparative Examples 1 to 5)
A lead-acid battery was produced in the same manner as in Example 1 except that the type of separator (base portion thickness, rib height) and aluminum ion concentration were changed as shown in Table 1.

<Evaluation of battery characteristics>
About the said lead acid battery, 5 hour rate capacity | capacitance, low-temperature high-rate discharge performance, charge acceptance performance, and the penetration short circuit evaluation were measured as follows. The results are shown in Table 1. In addition, "-" in Table 1 means that aluminum sulfate was not blended.

(5 hour rate capacity)
The produced battery was discharged at a constant current at an ambient temperature of 25 ° C. and 5.6 A, and the 5-hour rate capacity was calculated from the discharge duration until the cell voltage fell below 1.75V. The 5-hour rate capacity was evaluated relative to the measurement result of Comparative Example 1 as 100.

(Low temperature high rate discharge performance)
The produced battery was discharged at a constant current at an ambient temperature of −15 ° C. and 150 A, and the discharge duration until the cell voltage fell below 1.0 V was measured. The low-temperature high-rate discharge performance was evaluated relative to the measurement result of Comparative Example 1 as 100.

(Charge acceptance performance)
The produced battery was discharged at a constant current of 25 ° C. for 30 minutes at 5.6 A, left for 6 hours, then charged at a constant current of 100 A at a constant voltage of 2.33 V for 60 seconds. The current value at second was measured. The charge acceptance performance was evaluated relative to the measurement result of Comparative Example 1 as 100.

(Permeation short circuit evaluation)
The produced battery was discharged at a constant current at an ambient temperature of 25 ° C. and 1.4 A, discharged until the cell voltage reached 1.75 V, then connected to a 10 W lamp at an ambient temperature of 40 ° C. and left for 5 days. . Thereafter, the battery was charged for 8 hours at a cell voltage of 2.33 V under a limiting current of 25 A at 25 ° C. Repeat the above discharge and charging to determine that a short circuit occurs when the current staggers (current fluctuations of 0.3 A or more) or the terminal current (approximately 8 hours later) remains high (3 A or more) during charging. The number of repetitions of was measured. The permeation short-circuit evaluation was relative evaluation with the measurement result of Comparative Example 1 as 100.

  In the Examples, it was confirmed that the charge acceptance performance was equal to or higher than that of Comparative Example 1, and the results of the penetration short circuit evaluation were superior to those of Comparative Example 1. On the other hand, in the comparative example, it was confirmed that at least one of charge acceptance performance and penetration short circuit evaluation was inferior. Moreover, it was confirmed that both the charge acceptance performance and the results of the penetration short circuit evaluation are excellent when the ratio H / T of the height H of the rib to the thickness T of the base portion in the separator is in the range of 2 to 6.

  DESCRIPTION OF SYMBOLS 10 ... Separator, 10a ... One side, 10b ... The other side, 11 ... Base part, 12 ... Rib, 13 ... Mini-rib, 14, 14a, 14b ... Electrode, 20 ... Bag separator, 22 ... Mechanical seal part, A ... Rib Lower base width, B: Rib upper base width, H: Rib height, T: Base part thickness.

Claims (2)

A lead storage battery comprising a positive electrode and a negative electrode facing each other via a separator, and an electrolyte solution,
The separator has a convex rib and a base portion that supports the rib,
A thickness T of the base portion is 0.25 mm or less;
The ratio H / T of the height H of the rib to the thickness T of the base portion is 2 to 6,
The electrolyte is seen containing aluminum ions,
The lead acid battery whose density | concentration of the said aluminum ion is 0.001-0.01 mol / L.   The lead acid battery according to claim 1, wherein the separator includes polyolefin.

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