JPWO2018100635A1 - Lead-acid battery and method for manufacturing the same - Google Patents

Abstract

A method for producing a lead-acid battery comprising a positive electrode, a negative electrode, a separator disposed between the positive electrode and the negative electrode, and an electrolyte solution, comprising a raw material for a negative electrode active material and particles containing barium And a step of obtaining a negative electrode having a negative electrode material containing the negative electrode active material and the particles, the average primary particle size of the particles before the chemical conversion treatment is 0.10 μm or less, A method for producing a lead-acid battery, wherein the electrolytic solution contains aluminum ions.

Description

  The present invention relates to a lead storage battery and a method for manufacturing the same.

  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 hybrids such as idling stop system cars (hereinafter referred to as “ISS cars”) that reduce engine operation time, and power generation control cars that use engine rotation for power without waste. Cars are being studied and the use of lead-acid batteries in micro-hybrid vehicles 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 chargeability of lead-acid batteries during charge / discharge cycles in accordance with the control of micro hybrid vehicles has been regarded as important, and DCA (Dynamic Charge Acceptance) evaluation in this form is being standardized. is there. That is, in lead acid batteries used in a partially charged state called PSOC, improvement in charge acceptability is required. As a technique relating to charge acceptability under PSOC, for example, a technique using a negative electrode plate containing barium sulfate having an average particle diameter of 0.5 μm or more is known (for example, see Patent Document 1 below).

JP 2003-36882 A

  By the way, it is calculated | required for lead storage battery to further improve charge acceptance. For example, a lead storage battery is required to have excellent charge acceptability as compared with the technique of Patent Document 1.

  An object of this invention is to provide the lead acid battery which can acquire the outstanding charge acceptance, and its manufacturing method.

  A method for producing a lead-acid battery according to the present invention is a method for producing a lead-acid battery comprising a positive electrode, a negative electrode, a separator disposed between the positive electrode and the negative electrode, and an electrolytic solution. An average primary step before the chemical conversion treatment of the particles, comprising a step of chemical conversion treatment of a mixture containing raw materials and particles containing barium to obtain a negative electrode having a negative electrode material containing the negative electrode active material and the particles. The particle size is 0.10 μm or less, and the electrolyte contains aluminum ions.

  A lead storage battery according to the present invention is a lead storage battery comprising a positive electrode, a negative electrode, a separator disposed between the positive electrode and the negative electrode, and an electrolyte, wherein the negative electrode is a raw material for the negative electrode active material. And a particle containing barium, and a negative electrode material containing a chemical conversion treatment product containing the mixture, the average primary particle size of the particles before chemical conversion treatment is 0.10 μm or less, and the electrolytic solution contains aluminum ions. contains.

  According to the present invention, excellent charge acceptability can be obtained.

The details of the mechanism for improving the charge acceptability are not clear, but are presumed as follows.
That is, as an additive contained in the negative electrode material, particles containing barium have a role of becoming a crystal nucleus of lead sulfate that is a product of a discharge reaction. And when the average primary particle diameter before the chemical conversion treatment of the particles containing barium is 0.10 μm or less, the size of lead sulfate generated during discharge after chemical conversion treatment becomes small, and the specific surface area of the negative electrode material becomes large. Therefore, the reaction site at the time of charge reaction increases, and charge acceptability is easy to improve.
In addition, when the electrolytic solution contains aluminum ions, the crystalline lead sulfate as a discharge product is prevented from being bonded to each other and growing into a large crystal under any low SOC. The solubility in the electrolytic solution is increased, or the diffusibility of the electrolytic solution into the electrode active material is improved by the high ion conductivity of aluminum ions, whereby the charge acceptability is easily improved.
It is estimated that charge acceptability improves by these effects.

  The aluminum ion concentration of the electrolytic solution is preferably 0.001 to 0.24 mol / L.

  The particles preferably contain a barium salt. The barium salt preferably contains barium sulfate.

  The compounding amount of the particles before the chemical conversion treatment is preferably 0.01 to 2.0% by mass based on the total mass of the negative electrode active material.

  ADVANTAGE OF THE INVENTION According to this invention, the lead acid battery which can obtain the outstanding charge acceptance property, and its manufacturing method can be provided.

FIG. 1 shows a separator. FIG. 2 is a cross-sectional view of the separator and the electrode. FIG. 3 is a drawing showing a bag-shaped separator and electrodes accommodated in the bag-shaped 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. In this specification, the numerical range indicated using “to” indicates a range including the numerical values described before and after “to” as the minimum value and the maximum value, respectively. In the numerical ranges described stepwise in this specification, the upper limit value or the lower limit value of a numerical range in a certain step may be replaced with the upper limit value or the lower limit value of a numerical range in another step. In the numerical range described in this specification, the upper limit value or the lower limit value of the numerical range may be replaced with the values shown in the examples. The materials exemplified in the present specification can be used singly or in combination of two or more unless otherwise specified. In the present specification, the content of each component in the composition is the total amount of the plurality of substances present in the composition unless there is a specific notice when there are a plurality of substances corresponding to each component in the composition. Means.

<Lead battery>
The lead storage battery according to the present embodiment includes, for example, an electrode (electrode plate or the like), a separator, an electrolytic solution (sulfuric acid solution or the like), and a battery case. The electrode, separator, and 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. The separator is disposed between the positive electrode and the negative electrode. Examples of the lead storage battery according to this embodiment include a liquid lead storage battery, a control valve type lead storage battery, a sealed 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 treatment. When the electrode material is unformed, the electrode material (unformed positive electrode material and unformed negative electrode material) contains a raw material of an electrode active material (positive electrode active material and negative electrode active material). 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.

(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 subjecting an unformed positive electrode active material to a chemical conversion treatment after aging and drying a positive electrode material paste containing a raw material for the positive electrode active material to obtain an unformed positive electrode active material. The positive electrode active material after the chemical conversion treatment 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, a lead powder manufactured by a ball mill type lead powder manufacturing machine or a Burton pot type lead powder manufacturing machine Mixture). 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 content of the positive electrode active material is preferably 95% by mass or more, more preferably 97% by mass or more, based on the total mass of the positive electrode material, from the viewpoint of further improving battery characteristics (capacity, discharge characteristics, charge acceptance, cycle characteristics, etc.). Is more preferable, and 99 mass% or more is still more preferable. The upper limit of the content of the positive electrode active material may be 100% by mass or less. The content of the positive electrode active material is the content of the positive electrode active material in the positive electrode material after the chemical conversion treatment.

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

(Negative electrode material)
In this embodiment, the negative electrode material contains a negative electrode active material and particles containing barium. The negative electrode material includes a chemical conversion treatment product of a mixture containing a raw material for the negative electrode active material and particles containing barium, and is obtained by chemical conversion treatment of the mixture. The negative electrode material may contain a negative electrode additive other than particles containing barium.

[Negative electrode active material]
The negative electrode active material can be obtained by subjecting an unformed negative electrode active material to a chemical conversion treatment after obtaining an unformed negative electrode 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 the chemical conversion treatment 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, a lead powder manufactured by a ball mill type lead powder manufacturing machine or a Burton pot type lead powder manufacturing machine Mixture). Examples of the constituent material of the unformed negative electrode active material include basic lead sulfate, metallic lead, and lower oxide.

  The content of the negative electrode active material is preferably 93% by mass or more, more preferably 95% by mass or more, based on the total mass of the negative electrode material, from the viewpoint of further improving battery characteristics (capacity, discharge characteristics, charge acceptance, cycle characteristics, etc.). Is more preferable, and 98 mass% or more is still more preferable. The upper limit of the content of the negative electrode active material may be 100% by mass or less. The content of the negative electrode active material is the content of the negative electrode active material in the negative electrode material after the chemical conversion treatment.

[Negative electrode additive]
{Particles containing barium}
The particles containing barium can contain a barium salt from the viewpoint of obtaining better charge acceptability. As the barium salt, barium sulfate is preferable from the viewpoint of obtaining excellent charge acceptability.

{Other additives}
The negative electrode material may further contain additives other than particles containing barium. 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); carbon materials (carbonaceous conductive materials, excluding carbon fibers); reinforcing short fibers, and the like. 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 having a sulfone group and / or a sulfonate group (hereinafter simply referred to as “bisphenol resins”), lignin sulfonic acid, and lignin sulfonate. It is done. 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-based resin comprises a bisphenol-based compound (bisphenol A, bisphenol S, etc.), an aminoalkyl sulfonic acid, an aminoalkyl sulfonic acid derivative, an aminoaryl sulfonic acid (4-aminobenzene sulfonic acid, etc.), and an aminoaryl sulfonic acid derivative. A resin obtained by reacting at least one selected from the group with at least one selected from the group consisting of formaldehyde and formaldehyde derivatives (paraformaldehyde and the like) is preferable.

  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.

(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 for the current collector include lead alloys such as 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, a current collector can be obtained by forming these materials into a lattice shape or a mesh shape by the above-described manufacturing method. The material and / or manufacturing method of the positive and negative electrode current collectors may be the same or different from each other.

(Separator)
The separator used for the lead storage battery is not particularly limited as long as it prevents electrical connection between the positive electrode and the negative electrode and allows the electrolyte solution to permeate sulfate ions. Specifically, the separator is microporous. Synthetic resin sheet, glass fiber and acid-resistant paper bonded together, and the like. The separator made of a microporous synthetic resin sheet preferably contains polyolefin (polyethylene or the like), and more preferably contains polyolefin and silica.

  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 rib 12 is formed in plural (many) in the center in the width direction of the separator 10 so as to extend in the longitudinal direction of the separator 10. The plurality of ribs 12 are disposed 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 plurality of (many) 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. Further, the mini-rib 13 may not be formed in the separator 10.

  The upper limit of the thickness T of the base portion 11 is preferably 0.25 mm or less, and more preferably 0.22 mm or less, from the viewpoint of obtaining further excellent charge acceptability and discharge characteristics. The lower limit of the thickness T of the base portion 11 is not particularly limited, but is preferably 0.1 mm or more and more preferably 0.15 mm or more from the viewpoint of easily suppressing a short circuit.

  The upper limit of the height H of the rib 12 (the height in the facing direction of the base portion 11 and the electrode 14) H is preferably 1 mm or less, more preferably 0.8 mm or less, from the viewpoint of obtaining further excellent charge acceptance. More preferably, it is 6 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 portion 11 is preferably 2 or more, more preferably 2.2 or more, and more preferably 2.5 or more, from the viewpoint of excellent oxidation resistance of the separator. Further preferred. 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 upper limit of the ratio H / T is preferably 6 or less from the viewpoint of excellent rib shape retention and the effect of suppressing a short circuit. If the ratio H / T is 6 or less, the distance between the positive electrode and the negative electrode is sufficient, and it is estimated that the short circuit is further 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 more preferably 5 or less, further preferably 4 or less, and particularly preferably 3 or less from the viewpoint of further excellent rib shape retention and a short circuit suppression effect.

  The upper bottom width B of the rib 12 (see FIG. 1B) 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. 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 a bag shape that wraps at least one of the positive electrode and the 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 the positive electrode may penetrate the separator due to the elongation of the positive electrode current collector. In the process of laminating an electrode (electrode plate, etc.), the separator is cut into two according to the length of the negative electrode (negative electrode plate, etc.), and wraps the negative electrode by crimping both sides of the separator. It preferably has a shape.

  FIG. 3 is a view showing a bag-like separator 20 and an electrode (for example, a negative electrode) 14 accommodated in the separator 20. As shown to Fig.1 (a), the separator 10 used for preparation of the separator 20 is formed in the elongate sheet form, for example. The separator 20 shown in FIG. 3 is obtained by cutting the separator 10 into an appropriate length, folding it in the longitudinal direction of the separator 10 and placing the electrodes 14 on the inside thereof, and superimposing them on both sides. It can obtain by welding (for example, the code | symbol 22 of FIG. 3 shows a mechanical seal part).

(Electrolyte)
The electrolytic solution contains aluminum ions from the viewpoint of obtaining excellent charge acceptability. 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 aluminum ion concentration (for example, the aluminum ion concentration in the case where the electrolytic solution contains aluminum sulfate) is preferably 0.001 mol / L or more based on the total amount of the electrolytic solution from the viewpoint of obtaining further excellent charge acceptance. 0.003 mol / L or more is more preferable, 0.01 mol / L or more is more preferable, 0.03 mol / L or more is particularly preferable, 0.05 mol / L or more is very preferable, and 0.10 mol / L or more is very preferable. 0.15 mol / L or more is even more preferable. The aluminum ion concentration is preferably 0.50 mol / L or less, more preferably 0.40 mol / L or less, and more preferably 0.30 mol / L or less, based on the total amount of the electrolytic solution, from the viewpoint of obtaining further excellent charge acceptability. More preferred is 0.24 mol / L or less. From these viewpoints, the aluminum ion concentration is preferably 0.001 to 0.50 mol / L, more preferably 0.003 to 0.40 mol / L, still more preferably 0.01 to 0.30 mol / L, and 03 to 0.24 mol / L is particularly preferable, 0.05 to 0.24 mol / L is very preferable, 0.10 to 0.24 mol / L is very preferable, and 0.15 to 0.24 mol / L is even more preferable. preferable. From the viewpoint of improving the discharge characteristics, the aluminum ion concentration may be 0.24 mol / L or less, 0.12 mol / L or less, or 0.06 mol / L based on the total amount of the electrolytic solution. Or 0.03 mol / L or less. The aluminum ion concentration may be 0.001 to 0.24 mol / L based on the total amount of the electrolytic solution from the viewpoint of obtaining further excellent charge acceptability and discharge characteristics. 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 crystalline lead sulfate, which is a discharge product, is further suppressed from bonding to grow into a large crystal under any low SOC. It is presumed that the charge acceptability is improved by further increasing the solubility in the electrolytic solution or by further improving the diffusibility of the electrolytic solution into the electrode active material due to the high ion conductivity of aluminum ions.

  The specific gravity of the electrolytic solution after the chemical conversion treatment 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, still more preferably 1.27 or more, and 1.275 or more, from the viewpoint that the osmotic short circuit or freezing is easily suppressed and the discharge characteristics are further excellent. Is 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.

(Battery case)
The battery case can accommodate an electrode (electrode plate or the like) inside. It is preferable that the battery case has a box body whose upper surface is opened and a lid body which covers the upper surface of the box body from the viewpoint of easily storing the electrodes. 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 stored.

  The material of the battery case is not particularly limited, but is required to have resistance to an electrolytic solution (sulfuric acid solution or the like). Specific examples of the material for the battery case include PP (polypropylene), PE (polyethylene), and ABS resin. When the material is PP, it is advantageous in terms of acid resistance, processability and economy. PP is advantageous in terms of workability as compared with ABS resin, which is difficult to thermally weld the battery case and the lid.

  When the battery case is composed of a box and a lid, the materials of the box and the lid may be the same material or different materials. As the material for the box and the lid, materials having the same thermal expansion coefficient are preferable from the viewpoint of not generating excessive stress.

<Method for producing lead-acid battery>
The method for producing a lead-acid battery according to the present embodiment includes a negative electrode material containing a negative electrode active material and barium-containing particles by subjecting a mixture containing a raw material of the negative electrode active material and particles containing barium to a chemical conversion treatment. The negative electrode preparation process which obtains the negative electrode which has is provided. In the negative electrode preparation step, for example, the negative electrode material disposed on the current collector can be subjected to chemical conversion treatment to obtain a negative electrode.

  The average primary particle diameter of the particles containing barium before the chemical conversion treatment is 0.10 μm or less from the viewpoint of obtaining excellent charge acceptability and discharge characteristics. When the average primary particle size exceeds 0.10 μm, the charge acceptability tends to decrease. By the way, in the said patent document 1, it is desirable that the average particle diameter of barium sulfate is 0.5 micrometer or more from a viewpoint of suppressing that the crystal | crystallization of lead sulfate couple | bonds together and grows into a big crystal | crystallization and a malfunction arises. It is described, and it is shown that charge acceptability decreases when the average particle diameter is 0.4 μm (Comparative Example 4 of Patent Document 1). On the other hand, in this embodiment, although the average primary particle diameter of the barium-containing particles is 0.10 μm or less, excellent charge acceptability can be obtained when the electrolytic solution contains aluminum ions. The average primary particle size of the barium-containing particles before the chemical conversion treatment is preferably 0.08 μm or less, more preferably 0.05 μm or less, and further preferably 0.03 μm or less from the viewpoint of obtaining further excellent charge acceptability and discharge characteristics. preferable. The lower limit of the average primary particle size before the chemical conversion treatment of the particles containing barium is not particularly limited, but is, for example, 0.01 μm. The average primary particle diameter of the particles containing barium can be obtained, for example, by obtaining a fixed direction diameter by an electron micrograph, and can be measured using a particle size measuring instrument manufactured by Shimadzu Corporation.

  The lead storage battery manufacturing method according to this 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 components including the electrodes. The process includes the negative electrode manufacturing process.

  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 contains the raw material of the negative electrode active material (such as lead powder) and particles containing barium, and a resin having a sulfone group and / or a sulfonate group (such as a bisphenol resin) as a dispersant. It is preferable to contain, and you may contain the other additive further.

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%. Drying conditions are preferably 15 to 30 hours at a temperature of 45 to 80 ° C.

  The negative electrode material paste can be obtained, for example, by the following method. First, particles containing barium (barium sulfate, etc.) and other additives (resin having sulfone group and / or sulfonate group, carbon material, reinforcing short fiber, etc.) are added to the negative electrode active material. To obtain a mixture by dry mixing. 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, the blending amount of the barium-containing particles before the chemical conversion treatment is preferably in the following range based on the total mass of the negative electrode active material (lead powder, etc.). The blending amount of the barium-containing particles is preferably 0.01% by mass or more, more preferably 0.1% by mass or more, and still more preferably 0.5% by mass or more from the viewpoint of obtaining further excellent charge acceptability. The blending amount of the barium-containing particles is preferably 2.0% by mass or less, more preferably 1.5% by mass or less, and still more preferably 1.0% by mass or less from the viewpoint of obtaining further excellent charge acceptability. From these viewpoints, the blending amount of the barium-containing particles is preferably 0.01 to 2.0% by mass, more preferably 0.1 to 1.5% by mass, and further 0.5 to 1.0% by mass. preferable.

  In the negative electrode material paste, when a resin having a sulfone group and / or a sulfonate group (such as a bisphenol-based resin), a carbon material, or a reinforcing short fiber is used, the 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).

  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%. As drying conditions, a temperature of 45 to 60 ° C. and 15 to 30 hours are preferable.

  In the assembling process, for example, the unformed negative electrode and the unformed positive electrode produced as described above are alternately stacked via separators, and the current collectors of the same polarity electrodes are connected (welded, etc.) with a strap. An electrode group is obtained. This electrode group is arranged in a battery case to produce an unformed battery. Next, after injecting an electrolyte into an unformed battery, a direct current is applied to perform a chemical conversion treatment (battery formation). The lead acid battery is obtained by adjusting the specific gravity of the electrolytic solution after the chemical conversion treatment to an appropriate specific gravity.

  The chemical conversion conditions and the specific gravity of the electrolytic solution 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 (= Min- ¹ ) was stirred for 5 minutes 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 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.)

<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 grid body (current collector) filled with 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. 1.0% by mass of barium sulfate particles having an average primary particle size shown in Table 1, 0.2% by mass of bisphenol-based resin (in terms of solid content), 0.1% by mass of reinforcing short fibers (acrylic fibers), A mixture containing 0.2% by mass of a carbon material (furnace 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 grid body (current collector) filled with 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.

[Preparation of separator]
A separator was prepared by processing a sheet-like material containing polyethylene and silica particles and having a plurality of linear ribs formed on one surface into a bag shape so that the surface on which the ribs are formed is on the outside. (See FIGS. 1 and 3). Details of the separator are shown below.
Total thickness: 0.75 mm (base portion thickness T: 0.2 mm, rib height H: 0.55 mm, H / T = 2.75)
Rib spacing: 7.35 mm, rib upper base width B: 0.4 mm, rib lower base width A: 0.8 mm

[Battery assembly]
The non-chemically formed negative electrode plate was accommodated in the obtained bag-shaped separator. Next, five unchemically formed positive electrode plates and six unchemically formed negative electrode plates accommodated in the bag-shaped separator were alternately laminated so that the ribs of the separator were in contact with the positive electrode plate. 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 D 5301). Thereafter, a sulfuric acid solution (specific gravity: 1.23) containing metal ions (aluminum ions) shown in Table 1 was injected into this battery, and a chemical conversion treatment was performed at a constant current of 9.6 A for 16 hours at 40 ° C. To obtain a lead-acid battery. The specific gravity of the electrolytic solution (sulfuric acid solution) after the chemical conversion treatment was 1.28. When the sulfuric acid solution contained aluminum ions, the aluminum ion concentration was adjusted using aluminum sulfate anhydride as the aluminum source.

<Evaluation of battery characteristics>
(Charge acceptance)
The produced lead acid battery was discharged at a constant current of 6 A for 30 minutes at an ambient temperature of 25 ° C., and then left for 6 hours. Thereafter, the lead storage battery was charged at a constant voltage of 2.33 V for 60 seconds under a limiting current of 100 A, and the current value at 5 seconds from the start of charging was measured. The charge acceptance was evaluated relative to the measurement result of Comparative Example 1 as 100, and the case where it exceeded 100 was evaluated as good. The results are shown in Table 1.

  DESCRIPTION OF SYMBOLS 10,20 ... Separator, 10a ... One side, 10b ... The other side, 11 ... Base part, 12 ... Rib, 13 ... Minirib, 14, 14a, 14b ... Electrode, 22 ... Mechanical seal part, A ... Bottom width of rib , B: rib top bottom width, H: rib height, T: base portion thickness.

Claims (6)

A method for producing a lead storage battery comprising a positive electrode, a negative electrode, a separator disposed between the positive electrode and the negative electrode, and an electrolyte solution,
A step of subjecting a mixture containing a raw material of the negative electrode active material and particles containing barium to a chemical conversion treatment to obtain a negative electrode having a negative electrode material containing the negative electrode active material and the particles;
The average primary particle size before chemical conversion treatment of the particles is 0.10 μm or less,
The manufacturing method of the lead acid battery in which the said electrolyte solution contains aluminum ion.   The manufacturing method of the lead acid battery of Claim 1 whose aluminum ion concentration of the said electrolyte solution is 0.001-0.24 mol / L.   The manufacturing method of the lead acid battery of Claim 1 or 2 with which the said particle | grain contains barium salt.   The manufacturing method of the lead acid battery of Claim 3 with which the said barium salt contains a barium sulfate.   The lead storage battery as described in any one of Claims 1-4 whose compounding quantity before the chemical conversion treatment of the said particle | grain is 0.01-2.0 mass% on the basis of the total mass of the raw material of the said negative electrode active material. Manufacturing method. A lead acid battery comprising a positive electrode, a negative electrode, a separator disposed between the positive electrode and the negative electrode, and an electrolyte solution,
The negative electrode has a negative electrode material containing a chemical conversion treatment product of a mixture containing a raw material of a negative electrode active material and particles containing barium,
The average primary particle size before chemical conversion treatment of the particles is 0.10 μm or less,
A lead acid battery in which the electrolyte contains aluminum ions.

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