lead-acid batteries

Abstract

To provide a terminal member capable of suppressing electrolyte leakage in a storage battery and a method for manufacturing the same.SOLUTION: A positive electrode terminal member 20 includes a positive electrode terminal 22, and a support portion 24 that supports the positive electrode terminal 22, and the support portion 24 contains a reaction product of an epoxy compound and a polyamine, and also contains a thiol group. A method for manufacturing a positive electrode terminal member 20 including a positive electrode terminal 22 and a support portion 24 that supports the positive electrode terminal 22 includes obtaining the support portion 24 by reacting an epoxy compound and a polyamine in the presence of a thiol compound.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present disclosure relates to a terminal member, a method for manufacturing the same, and a storage battery (for example, a lead storage battery) and the like.

Background Art

[0002] As the storage battery, various batteries such as a lead storage battery are used. For example, the storage battery includes a terminal member having a terminal and a support portion that supports the terminal (see, for example, Patent Document 1 below).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In a storage battery including a terminal member, for example, if the adhesion between a support portion and a member (for example, a terminal) that abuts on the support portion is not sufficient, the electrolyte may leak from the inside of the storage battery.

[0005] One aspect of the present disclosure aims to provide a terminal member capable of suppressing electrolyte leakage in a storage battery. Another aspect of the present disclosure aims to provide a method for manufacturing a terminal member for obtaining such a terminal member. Another aspect of the present disclosure aims to provide, as an example of a storage battery, a lead storage battery including such a terminal member.

Means for Solving the Problems

[0006] The present disclosure relates to the following [1] to [6] and the like in some aspects. [1] A terminal member having a terminal and a support portion that supports the terminal, wherein the support portion contains a reaction product of an epoxy compound and a polyamine and includes a thiol group. [2] The terminal member according to [1], wherein the thiol group of the support portion is a thiol group derived from a thiol compound having a pentaerythritol skeleton. [3] The terminal member according to [1] or [2], wherein the thiol group of the support portion is a thiol group derived from a thiol compound with a molecular weight of 800 or less. [4] The terminal member according to any one of [1] to [3], wherein the content of the thiol compound that gives the thiol group is more than 0 parts by mass and 30 parts by mass or less per 100 parts by mass of the epoxy compound. A lead-acid battery having a terminal component described in any one of [5][1] to [4]. [6] A method for manufacturing a terminal member having a terminal and a support portion for supporting the terminal, wherein the support portion is obtained by reacting an epoxy compound with a polyamine in the presence of a thiol compound. [Effects of the Invention]

[0007] According to one aspect of this disclosure, a terminal member capable of suppressing electrolyte leakage in a storage battery can be provided. According to another aspect of this disclosure, a method for manufacturing such a terminal member can be provided. According to yet another aspect of this disclosure, as an example of a storage battery, a lead-acid battery equipped with such a terminal member can be provided. [Brief explanation of the drawing]

[0008] [Figure 1] Figure 1 is an exploded perspective view showing an example of a lead-acid battery. [Figure 2] Figure 2 is a perspective view showing a portion of the lead-acid battery shown in Figure 1. [Figure 3] Figure 3 is a perspective cross-sectional view along the line III-III in Figure 2. [Figure 4] Figure 4 is a cross-sectional view along the line IV-IV in Figure 2. [Modes for carrying out the invention]

[0009] The embodiments of this disclosure will be described below, but this disclosure is not limited to these embodiments.

[0010] In this specification, numerical ranges indicated using "~" represent a range that includes the numbers before and after "~" as the minimum and maximum values, respectively. In numerical ranges described stepwise in this specification, the upper or lower limit of a numerical range in one step can be arbitrarily combined with the upper or lower limit of a numerical range in another step. In numerical ranges described in this specification, the upper or lower limit of that numerical range may be replaced with the values ​​shown in the examples. "A or B" means that either A or B is included, or both are included. Unless otherwise specified, the materials exemplified in this specification can be used individually or in combination of two or more. The content of each component in a composition means the total amount of multiple substances present in the composition if there are multiple substances corresponding to each component in the composition, unless otherwise specified. The term "process" includes not only independent processes but also processes that are not clearly distinguishable from other processes, as long as the intended function of the process is achieved. Since specific gravity changes with temperature, in this specification it is defined as specific gravity converted at 25°C. "(Meth)acrylic" means at least one of acrylic and its corresponding methacrylic.

[0011] The terminal member according to this embodiment comprises a terminal and a support portion that supports the terminal. The support portion contains a reaction product of an epoxy compound and a polyamine (hereinafter referred to as "reaction product R," for example, a cured product). The support portion also contains a thiol group.

[0012] The support portion may contain thiol groups because the reactant R has thiol groups, and the reactant R may be a reaction product of an epoxy compound, a polyamine, and a thiol compound (a compound having thiol groups). Alternatively, the support portion may contain thiol groups by containing a thiol compound as a compound different from the reactant R. The reactant R may have thiol groups, while the support portion may contain a thiol compound as a compound different from the reactant R. The support portion may contain a compound other than a thiol compound as a compound different from the reactant R.

[0013] The terminal member according to this embodiment can suppress electrolyte leakage in a storage battery. Because the support portion contains a reactant R and a thiol group, when the electrolyte (e.g., sulfuric acid) comes into contact with the support portion, the decrease in adhesion between the support portion and the member in contact with the support portion is suppressed (e.g., improved acid resistance), and thus electrolyte leakage is suppressed. However, the factors that suppress electrolyte leakage are not limited to this. The terminal member according to this embodiment can be used as a sealing agent for storage batteries.

[0014] The terminal is electrically conductive and is made of a conductive material. Examples of conductive materials include metallic materials and carbon materials. Examples of metallic materials include lead, copper, and zinc, and may also be an alloy of multiple metals. The terminal may be made of multiple components, and the constituent materials of the multiple components may be the same or different from each other.

[0015] The terminals may be positive or negative. The shape and arrangement of the terminals are not particularly limited. The terminals may be elongated members extending in the axial direction. The terminals may be located on the top surface of the battery, or on other parts of the battery (e.g., the sides). The terminals may extend vertically, or in a direction intersecting the vertical (a direction inclined from the vertical, e.g., horizontally).

[0016] The support portion supports the terminal and may be in contact with the terminal. The terminal does not necessarily have to be supported only by the support portion of the terminal member according to the present embodiment, and may be supported by the support portion and other members. The shape, arrangement, etc. of the support portion are not particularly limited. The support portion may be disposed on the upper surface of the storage battery, or may be disposed on a portion other than the upper surface of the storage battery (for example, a side surface).

[0017] The support portion contains a reaction product R of an epoxy compound and a polyamine (excluding a compound corresponding to the epoxy compound) and contains a thiol group (mercapto group). The reaction product R may be a reaction product of an epoxy compound, a polyamine, and a compound other than the epoxy compound and the polyamine, or may be a reaction product of an epoxy compound, a polyamine, and a thiol compound.

[0018] The epoxy compound is a compound having one or more epoxy groups in the molecule. The epoxy compound may be an epoxy compound having a thiol group or may be an epoxy compound not having a thiol group.

[0019] The number of epoxy groups in the epoxy compound may be in the following range from the viewpoint of easily suppressing electrolyte leakage. The number of epoxy groups may be 1 or more, or 2 or more. The number of epoxy groups may be 5 or less, 4 or less, 3 or less, or 2 or less. From these viewpoints, the number of epoxy groups may be 1 to 5.

[0020] The epoxy equivalent of the epoxy compound may be in the following range from the viewpoint of easily suppressing electrolyte leakage. The epoxy equivalent may be 100 or more, 120 or more, 140 or more, 150 or more, 160 or more, or 170 or more. The epoxy equivalent may be 500 or less, 400 or less, 300 or less, 250 or less, 230 or less, 210 or less, or 200 or less. From these viewpoints, the epoxy equivalent may be 100 to 500.

[0021] Examples of epoxy compounds include bisphenol A type epoxy compounds, bisphenol S type epoxy compounds, bisphenol F type epoxy compounds, phenol novolac type epoxy compounds, and cresol novolac type epoxy compounds. From the viewpoint of easily suppressing electrolyte leakage, the epoxy compound may contain bisphenol A type epoxy compounds and may also contain 2,2-bis(4-glycidyloxyphenyl)propane.

[0022] From the viewpoint of easily suppressing electrolyte leakage, the epoxy compound content in the support portion may be within the following ranges based on the total mass of the support portion: The epoxy compound content may be 50% by mass or more, more than 50% by mass, 60% by mass or more, 65% by mass or more, 70% by mass or more, or 75% by mass or more. The epoxy compound content may be 80% by mass or more. The epoxy compound content may be less than 100% by mass, 95% by mass or less, 90% by mass or less, 85% by mass or less, or 80% by mass or less. The epoxy compound content may be 75% by mass or less. From these viewpoints, the epoxy compound content may be 50% by mass or more and less than 100% by mass.

[0023] Examples of polyamines include aliphatic polyamines, alicyclic polyamines, aromatic polyamines, and heterocyclic polyamines. Polyamines may be modified products. Methods of modification include modification by the Mannich reaction between a phenol compound and an aldehyde compound; modification by reaction with a compound having a carboxyl group; and modification by the Michael addition reaction with a (meth)acrylic compound. Polyamines may be polyamines having thiol groups, or they may be polyamines without thiol groups.

[0024] From the viewpoint of easily suppressing electrolyte leakage, the polyamine content in the support part or reactant R may be within the following ranges per 100 parts by mass of epoxy compound: The polyamine content may be 1 part by mass or more, 5 parts by mass or more, 10 parts by mass or more, 12 parts by mass or more, 15 parts by mass or more, or 18 parts by mass or more. The polyamine content may be 50 parts by mass or less, 40 parts by mass or less, 30 parts by mass or less, 25 parts by mass or less, 20 parts by mass or less, or 18 parts by mass or less. From these viewpoints, the polyamine content may be between 1 and 50 parts by mass.

[0025] From the viewpoint of easily suppressing electrolyte leakage, the polyamine content in the support portion may be within the following ranges based on the total mass of the support portion: The polyamine content may be 1% by mass or more, 5% by mass or more, 8% by mass or more, 10% by mass or more, 12% by mass or more, 13% by mass or more, or 14% by mass or more. The polyamine content may be 14.5% by mass or more. The polyamine content may be 50% by mass or less, 40% by mass or less, 30% by mass or less, 25% by mass or less, 20% by mass or less, 15% by mass or less, or 14.5% by mass or less. The polyamine content may be 14% by mass or less. From these viewpoints, the polyamine content may be between 1 and 50% by mass.

[0026] Thiol compounds can be used to provide thiol groups in the support structure. That is, the thiol groups in the support structure may be thiol groups derived from a thiol compound.

[0027] The thiol compound may include monofunctional thiol compounds or polyfunctional thiol compounds. The thiol compound may include aliphatic thiol compounds or aromatic thiol compounds.

[0028] Thiol compounds include 2,3-dimercaptosuccinate, ethylene glycol bis(3-mercaptopropionate), 1,4-butanediol bisthioglycolate, ethylene glycol bisthioglycolate, trimethylolpropane tristhioglycolate, 1,2,6-hexanetriol trithioglycolate, 1,4-bis(3-mercaptobutyryloxy)butane, trimethylolpropane tris(3-mercaptopropionate), and trimethylolpropane. Pantrys(3-mercaptobutyrate), pentaerythritol tetrakis(3-mercaptobutyrate), 1,2-ethanedithiol, 1,3-propanedithiol, 1,4-butanedithiol, 2,3-butanedithiol, 1,5-pentanedithiol, 1,6-hexanedithiol, 1,8-octanedithiol, 1,9-nonanedithiol, 2,3-dimercapto-1-propanol, dithioerythritol, 1,2-benzenedimethanethiol, 1,3-benzene Dimethanethiol, 1,4-benzenedimethanethiol, 2,4,6-trimethyl-1,3-benzenedimethanethiol, 2,2'-(ethylenedithio)diethanethiol, 1,2-benzenedithiol, 1,3-benzenedithiol, 1-methyl-3,4-benzenedithiol, 4-chloro-1,3-benzenedithiol, 2,2-bis(2-hydroxy-3-mercaptopropoxyphenylpropane), 2,5-dimercapto-1,3,4-thiadiazole, 1,3,5- Examples include trithiocyanuric acid, 2-hexylamino-4,6-dimercapto-1,3,5-triazine, 2-diethylamino-4,6-dimercapto-1,3,5-triazine, 2-cyclohexylamino-4,6-dimercapto-1,3,5-triazine, 2-di-n-butylamino-4,6-dimercapto-1,3,5-triazine, and 1,3,5-tris(2-(3-sulfanylbutanoyloxy)ethyl)-1,3,5-triazinan-2,4,6-trione.

[0029] From the viewpoint of easily suppressing electrolyte leakage, the thiol compound may include a thiol compound having a pentaerythritol skeleton, which improves the durability of the support by increasing the flexibility of the support; that is, the thiol group of the support may be a thiol group derived from a thiol compound having a pentaerythritol skeleton. From the viewpoint of easily suppressing electrolyte leakage, the thiol compound may include a thiol compound that does not have a thiol group bonded to a terminal carbon atom (e.g., the end of a carbon chain). From the viewpoint of easily suppressing electrolyte leakage, the thiol compound may include a thiol compound that has a thiol group bonded to a carbon atom not located at the terminal (e.g., the end of a carbon chain).

[0030] The number of thiol groups in a thiol compound may be within the following ranges, from the viewpoint of easily suppressing electrolyte leakage: The number of thiol groups may be 1 or more, 2 or more, 3 or more, or 4 or more. The number of thiol groups may be 10 or less, 8 or less, 6 or less, 5 or less, or 4 or less. From these viewpoints, the number of thiol groups may be between 1 and 10. The number of thiol groups bonded to carbon atoms not located at the ends (e.g., the ends of a carbon chain) may be within each of the above-mentioned ranges for the number of thiol groups.

[0031] Thiol compounds may contain ester bonds from the viewpoint of easily suppressing electrolyte leakage. The number of ester bonds in a thiol compound may be within the following ranges from the viewpoint of easily suppressing electrolyte leakage: The number of ester bonds may be 1 or more, 2 or more, 3 or more, or 4 or more. The number of ester bonds may be 10 or less, 8 or less, 6 or less, 5 or less, or 4 or less. From these viewpoints, the number of ester bonds may be between 1 and 10.

[0032] The molecular weight of the thiol compound may be within the following ranges from the viewpoint of easily suppressing electrolyte leakage. The molecular weight of the thiol group may be 100 or more, 200 or more, 300 or more, 350 or more, 400 or more, 450 or more, or 500 or more. The molecular weight of the thiol group may be 1000 or less, less than 1000, 900 or less, 800 or less, 700 or less, 600 or less, or 550 or less. From these viewpoints, the molecular weight of the thiol group may be between 100 and 1000. The thiol group of the support part may be a thiol group derived from a thiol compound with a molecular weight within each of the above ranges.

[0033] The content of thiol compounds (thiol compounds that give thiol groups) in the support or reactant R may be within the following ranges per 100 parts by mass of epoxy compound, from the viewpoint of easily suppressing electrolyte leakage. The content of thiol compounds may be greater than 0 parts by mass, 0.1 parts by mass or more, 0.5 parts by mass or more, 1 part by mass or more, 3 parts by mass or more, 5 parts by mass or more, 8 parts by mass or more, or 10 parts by mass or more. The content of thiol compounds may be 15 parts by mass or more, or 20 parts by mass or more. The content of thiol compounds may be 50 parts by mass or less, 40 parts by mass or less, less than 40 parts by mass, 30 parts by mass or less, 25 parts by mass or less, 20 parts by mass or less, 15 parts by mass or less, or 10 parts by mass or less. The content of thiol compounds may be 8 parts by mass or less, or 5 parts by mass or less. From these viewpoints, the content of thiol compounds may be greater than 0 parts by mass and 50 parts by mass or less, greater than 0 parts by mass and less than 40 parts by mass, or greater than 0 parts by mass and 30 parts by mass or less.

[0034] The content of thiol compounds (thiol compounds that give thiol groups) in the support or reactant R may be within the following ranges per 100 parts by mass of polyamine, from the viewpoint of easily suppressing electrolyte leakage. The content of thiol compounds may be 10 parts by mass or more, 20 parts by mass or more, 25 parts by mass or more, 30 parts by mass or more, 35 parts by mass or more, 40 parts by mass or more, 45 parts by mass or more, 50 parts by mass or more, or 55 parts by mass or more. The content of thiol compounds may be 60 parts by mass or more, 80 parts by mass or more, or 100 parts by mass or more. The content of thiol compounds may be 150 parts by mass or less, 120 parts by mass or less, 100 parts by mass or less, less than 100 parts by mass, 90 parts by mass or less, 80 parts by mass or less, 75 parts by mass or less, 70 parts by mass or less, 65 parts by mass or less, or 60 parts by mass or less. The content of thiol compounds may be 50 parts by mass or less, 40 parts by mass or less, or 30 parts by mass or less. From these perspectives, the content of the thiol compound may be 10 to 150 parts by mass.

[0035] The content of thiol compounds (thiol compounds that provide thiol groups) in the support portion may be within the following ranges based on the total mass of the support portion, from the viewpoint of easily suppressing electrolyte leakage. The content of thiol compounds may be greater than 0 mass%, 0.1 mass or more, 0.5 mass or more, 1 mass or more, 3 mass or more, 5 mass or more, 6 mass or more, or 7 mass or more. The content of thiol compounds may be 8 mass or more, 10 mass or more, or 12 mass or more. The content of thiol compounds may be 30 mass or less, 25 mass or less, 20 mass or less, 15 mass or less, 12 mass or less, 10 mass or less, or 8 mass or less. The content of thiol compounds may be 6 mass or less, or 5 mass or less. From these viewpoints, the content of thiol compounds may be greater than 0 mass% and 30 mass or less.

[0036] The method for manufacturing a terminal member according to this embodiment is a method for manufacturing a terminal member having a terminal and a support portion that supports the terminal, and comprises a reaction step of obtaining the support portion by reacting an epoxy compound and a polyamine in the presence of a thiol compound. In this case, since the thiol compound promotes the reaction between the epoxy compound and the polyamine, the amount of unreacted components (e.g., unreacted polyamine) is easily reduced, and therefore, when an electrolyte (e.g., sulfuric acid) comes into contact with the support portion, it is easy to obtain an effect that suppresses a decrease in adhesion between the support portion and the member in contact with the support portion (e.g., an effect of improving acid resistance).

[0037] In the reaction step, the support may be obtained by heating a mixture containing an epoxy compound and a polyamine in the presence of a thiol compound, or by heating a mixture of an epoxy compound, a polyamine, and a thiol compound.

[0038] In the reaction step, the support portion may be obtained by reacting an epoxy compound with a polyamine in the presence of a thiol compound at the sealing portion (terminal sealing portion) where the support portion is to be formed. The sealing portion is a place where electrolyte may leak from inside the battery.

[0039] In the method for manufacturing the terminal member according to this embodiment, the various characteristics described above regarding the terminal member according to this embodiment can be used as various characteristics such as the types of epoxy compounds, polyamines, and thiol compounds used in the reaction step, as well as the amounts used.

[0040] The storage battery according to this embodiment includes a terminal member according to this embodiment. Examples of storage batteries include lead-acid batteries, zinc batteries, lithium-ion batteries, lithium-ion capacitors, nickel-cadmium batteries, nickel-metal hydride batteries, sodium-sulfur batteries, redox flow batteries, fuel cells, etc. The storage battery according to this embodiment may include a terminal member according to this embodiment as at least one selected from the group consisting of a positive electrode terminal member and a negative electrode terminal member. As an example of a storage battery according to this embodiment, the lead-acid battery according to this embodiment includes a terminal member according to this embodiment. In the method for manufacturing the storage battery according to this embodiment, the storage battery is obtained using the terminal member according to this embodiment. In the method for manufacturing the storage battery according to this embodiment, the storage battery can be obtained by any method.

[0041] The storage battery according to this embodiment may comprise a terminal member according to this embodiment, a battery case, an electrolyte, and an electrode group, wherein the electrolyte and the electrode group are housed in the battery case.

[0042] The terminal member may be electrically connected to the electrodes of the electrode group. The terminal member may be a lid that seals the battery case, or it may be part of a component that makes up the lid.

[0043] The electrolyte may contain components depending on the type of battery. For example, the electrolyte of a lead-acid battery may contain sulfuric acid.

[0044] An electrode group is an assembly of multiple electrodes and may have multiple electrodes (e.g., electrode plates) and a separator. The electrode group may have a positive electrode (e.g., a positive electrode plate) and a negative electrode (e.g., a negative electrode plate) as electrodes. At least a portion of the electrodes may be immersed in an electrolyte. The electrode (positive electrode or negative electrode) may have an electrode active material (positive electrode active material or negative electrode active material) and a current collector that supports the electrode active material.

[0045] The electrode active material may contain components depending on the type of battery. For example, the positive electrode active material and negative electrode active material of a lead-acid battery may contain lead components (components containing lead). Unprocessed positive electrode active material may contain tribasic lead sulfate as its main component. Examples of raw materials for positive electrode active material include lead powder and red lead (Pb3O4). Unprocessed negative electrode active material may contain tribasic lead sulfate as its main component. Examples of raw materials for negative electrode active material include lead powder.

[0046] The current collector may be formed from materials appropriate to the type of battery. For example, the materials used for the current collector of a lead-acid battery include lead alloys such as lead-calcium-tin alloys and lead-antimony-arsenide alloys.

[0047] A separator is a component that prevents short circuits between the positive and negative electrodes. The separator can be made of a material that electrically insulates the positive and negative electrodes while allowing ions to pass through, and that is resistant to oxidation on the positive electrode side and reduction on the negative electrode side. The separator may also be in a bag shape, covering the main part of the electrode (e.g., the negative electrode). The separator may be formed from a material depending on the type of battery. Examples of separator materials include glass fiber, resin, and inorganic materials.

[0048] As an example of a storage battery, the configuration of a lead-acid battery will be explained with reference to Figures 1 to 4. Figure 1 is an exploded perspective view showing an example of a lead-acid battery. Figure 2 is a perspective view showing a part of the lead-acid battery shown in Figure 1. Figure 3 is a perspective cross-sectional view along line III-III in Figure 2. Figure 4 is a cross-sectional view along line IV-IV in Figure 2. In Figures 1 to 4, the first direction X and the second and third directions Y and Z, which are perpendicular to the first direction X, are shown.

[0049] The lead-acid battery 100 shown in Figure 1 is, for example, a valve-regulated lead-acid battery. The lead-acid battery 100 mainly comprises an electrode group 10, a positive electrode terminal member 20, a negative electrode terminal member 30, a control valve 40, a case 50, and an electrolyte (not shown). The electrode group 10 has a plurality of positive electrodes 12, a plurality of negative electrodes 14, and a plurality of separators 16. The positive electrode terminal member 20 has a positive electrode terminal 22 and a support portion 24 that supports the positive electrode terminal 22. The negative electrode terminal member 30 may have a similar configuration to the positive electrode terminal member 20, and has a negative electrode terminal 32 and a support portion 34 that supports the negative electrode terminal 32. The case 50 has a battery case 52 and a lid 54 that covers the opening of the battery case 52. Figure 2 shows the lid 54 with the control valve 40 removed.

[0050] In the electrode group 10, positive electrodes 12 and negative electrodes 14 are arranged alternately in the first direction X. A separator 16 is located between adjacent positive electrodes 12 and negative electrodes 14. Therefore, the positive electrodes 12, separators 16, and negative electrodes 14 overlap in the first direction X. In the electrode group 10, the negative electrodes 14 are located at the ends in the arrangement direction (first direction X) of the positive electrodes 12, negative electrodes 14, and separators 16. When the electrode group 10 and electrolyte are housed in the case 50's battery case 52, the electrolyte is present in the gap between the positive electrodes 12 and the separators 16, inside the separators 16, etc.

[0051] The positive electrode 12 is electrically connected to the positive electrode terminal 22 of the positive electrode terminal member 20. Each positive electrode 12 and the positive electrode terminal 22 are electrically connected by a positive electrode strap 12a. The negative electrode 14 is electrically connected to the negative electrode terminal 32 of the negative electrode terminal member 30. Each negative electrode 14 and the negative electrode terminal 32 are electrically connected by a negative electrode strap 14a.

[0052] The positive terminal 22 of the positive terminal member 20 and the negative terminal 32 of the negative terminal member 30 are terminals for electrically connecting the electrode group 10 to an external device. The positive terminal 22 has, for example, a first terminal portion 22a fixed to the cover 54 and a second terminal portion 22b fixed to the first terminal portion 22a. The first terminal portion 22a is a conductive material containing lead. The first terminal portion 22a may be formed mainly of lead, or may be formed solely of lead. The second terminal portion 22b is a core portion formed from a metal or alloy. The second terminal portion 22b is, for example, formed from an alloy of copper and zinc (brass). The negative terminal 32 may have a similar configuration to the positive terminal 22.

[0053] The support portion 24 of the positive electrode terminal member 20 and the support portion 34 of the negative electrode terminal member 30 contain a reaction product of an epoxy compound and a polyamine, as well as a thiol group. The support portion 24 is located in the recessed terminal sealing portion 24a. The support portion 24 is in contact with the positive electrode terminal 22. The support portion 34 of the negative electrode terminal member 30 may have the same configuration as the support portion 24. The support portion 34 is located in the recessed terminal sealing portion 34a. The support portion 34 is in contact with the positive electrode terminal 22.

[0054] The battery case 52 of the case 50 is box-shaped. The battery case 52 is made of a material such as polypropylene. The battery case 52 houses the electrode group 10 and the electrolyte. The lid 54 of the case 50 is roughly plate-shaped and is made of a material such as polypropylene. The lid 54 is provided with through holes for arranging the positive electrode terminal 22 and the negative electrode terminal 32, and a cylindrical portion 40a with a through hole for arranging the control valve 40 is provided. [Examples]

[0055] The present disclosure will be described in more detail below with reference to examples and comparative examples, but the present disclosure is not limited to the following examples.

[0056] <Example 1> A sealing agent was prepared by stirring 100 parts by mass of a bisphenol A type epoxy compound (manufactured by Mitsubishi Chemical Corporation, trade name: jER828), 18 parts by mass of a modified polyamine (manufactured by Mitsubishi Chemical Corporation, trade name: jER Cure TO184), and 5 parts by mass of a thiol compound (pentaerythritol tetrakis(3-mercaptobutyrate), manufactured by Showa Denko K.K., trade name: Karenz MT PE1) until homogeneous.

[0057] Two lead-acid batteries having the structures shown in Figures 1-4 were prepared. The sealing agent described above was injected into the terminal sealing area of ​​the lead-acid batteries and then cured in a curing oven at 80°C for 2 hours. After curing, the terminal section was cut from the lid using a hole saw, including a portion of the lid, and the lid and battery case were separated using a saw, along with the poles and straps, to remove only the terminal components (positive and negative terminal components) from the batteries. The poles of the two removed positive terminal components were connected with a wire, and a rod heater was attached to the hole in the pole of each terminal component to create a positive terminal component for heat cycle testing. A negative terminal component for heat cycle testing was also created using the same procedure. The terminal components for heat cycle testing (two positive terminal components and two negative terminal components) were arranged in a container, and sulfuric acid with a specific gravity of 1.27 was added to the container until the bottom of the terminals were submerged to about 10 mm. Next, the terminal component for the heat cycle test was placed in a constant temperature bath cooled to 0°C while still in its container. With the terminals of the heat cycle test component connected in series to a DC stabilized power supply and the rod heater connected to a rod heater control device, the test specimen was obtained by cooling the terminals and sulfuric acid until they reached 0°C.

[0058] A voltage of 2.23V was applied to the aforementioned test specimen in a 0°C constant temperature bath, and the specimen was heated to 60°C at a heating rate of 25°C / min using a rod heater. The specimen was then left in the 0°C constant temperature bath without maintaining its temperature at 60°C. One hour after the start of heating, the specimen was again heated to 60°C at a heating rate of 25°C / min using the rod heater. The number of cycles in the heat cycle test was counted, with one cycle defined as the period from the start of heating to the start of the next heating cycle. The heat cycle test was interrupted once a week to replace the sulfuric acid and to check for leakage from the terminal seal. Leakage from the terminal seal was checked by wiping the terminal seal with water and then applying pH test paper to the contact points between the terminal seal and the terminal, and between the terminal seal and the lid. Leakage was determined to have occurred if the pH of the pH test paper showed a pH of 2 or less at at least one contact point, and the number of cycles at that point was determined to be the number of cycles in which leakage occurred.

[0059] As a result of preparing the test specimens and conducting two heat cycle tests as described above, the average number of cycles in which leakage occurred in Example 1 was 3990 cycles.

[0060] <Example 2> Except for changing the amount of thiol compound used from 5 parts by mass to 10 parts by mass, test specimens were prepared in the same manner as in Example 1, and a heat cycle test was performed. In Example 2, the average number of cycles in which leakage occurred was 5060 cycles.

[0061] <Example 3> Except for changing the amount of thiol compound used from 5 parts by mass to 20 parts by mass, test specimens were prepared in the same manner as in Example 1, and a heat cycle test was performed. In Example 3, the average number of cycles in which leakage occurred was 3570 cycles.

[0062] <Comparative Example 1> A test specimen was prepared in the same manner as in Example 1, except that the amount of thiol compound used was changed from 5 parts by mass to 0 parts by mass, and a heat cycle test was performed. In Comparative Example 1, the average number of cycles in which leakage occurred was 1820 cycles. [Explanation of Symbols]

[0063] 10... Electrode group, 12... Positive electrode, 12a... Positive electrode strap, 14... Negative electrode, 14a... Negative electrode strap, 16... Separator, 20... Positive electrode terminal member, 22... Positive electrode terminal, 22a... First terminal section, 22b... Second terminal section, 24... Support section, 24a... Terminal sealing section, 30... Negative electrode terminal member, 32... Negative electrode terminal, 34... Support section, 34a... Terminal sealing section, 40... Control valve, 40a... Cylinder section, 50... Case, 52... Battery case, 54... Lid, 100... Lead-acid battery.

Claims

1. A lead-acid battery comprising a terminal member, The terminal member comprises a terminal and a support portion that supports the terminal. A lead-acid battery wherein the support portion contains a reaction product of an epoxy compound and a polyamine, and also contains a thiol group.

2. The lead-acid battery according to claim 1, wherein the thiol group of the support portion is a thiol group derived from a thiol compound having a pentaerythritol skeleton.

3. The lead-acid battery according to claim 1, wherein the thiol group of the support portion is a thiol group derived from a thiol compound with a molecular weight of 800 or less.

4. The lead-acid battery according to claim 1, wherein the content of the thiol compound that gives the thiol group is more than 0 parts by mass and 30 parts by mass or less per 100 parts by mass of the epoxy compound.

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