JP2008027849A - Seal member - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a seal member capable of securing a high sealing property. <P>SOLUTION: This seal member is used for a sealing plate for a battery case having a lid plate forming a part of the battery case, an electrode terminal, and the seal member arranged between the lid plate and the electrode terminal. The seal member is formed of an unreinforced polyphenylene sulfide resin bonded to at least either of the electrode terminal and the lid plate by chemical bonding, and is characterized in that the crystallinity of the resin is not smaller than 35%. The seal member has a high sealing property (high adhesive strength, durability and water permeability resistance). <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a seal member, and more particularly to a seal member that seals between a battery container made of metal and an electrode terminal in a battery.

  2. Description of the Related Art In recent years, lithium batteries with large capacity, high output, and high energy density have attracted attention as in-vehicle power sources for driving vehicles such as automobiles.

As such a lithium battery, an electrode body in which a positive electrode and a negative electrode in which a solid electrode mainly composed of an active material such as LiNiO ₂ is formed on the surface of a current collecting member made of a metal foil or the like is arranged to face _each other through a separator is used. A non-aqueous electrolyte impregnated and accommodated in a bottomed container and sealed with a metal lid is known.

  However, a non-aqueous electrolyte battery such as a lithium battery has a problem in that battery performance deteriorates when moisture enters the inside of the battery container. Specifically, when moisture is present inside the container of the nonaqueous electrolyte battery, the moisture and the nonaqueous electrolyte react to generate hydrofluoric acid. The generated hydrofluoric acid eroded the electrode, reducing the performance such as battery capacity and battery life.

  For this reason, in a lithium battery, in order to suppress the penetration | invasion of the water | moisture content from the outside, it was necessary to fully maintain the sealing performance of the inside and outside of a battery container. In a conventional lithium battery, a sealing mechanism using an O-ring is generally known as a seal for a gap between electrode bodies protruding from the inside of the battery through the lid and the lid.

  However, the O-ring sealing mechanism has a problem of cost increase due to an increase in the number of parts.

  In order to solve this problem, a sealing structure is known in which an insulating sealing member made of resin is bonded to a battery upper lid and an electrode terminal to maintain a sealing property between the inside and outside of the battery. For example, in Patent Document 1, a metal member having a through hole on the inner peripheral side on which a coating layer made of triazine thiols or a silane coupling agent is formed, and a pair of electrode terminals inserted through the through hole are made of gold. A battery lid body is described in which the lid body and the electrode terminal are firmly bonded to each other through an insulating sealing member by inserting a resin in the space between the lid body and the electrode terminal. ing. This lid is closed by ultrasonic welding at the opening of the bottomed cylindrical container.

  However, if a thin lid is used for the lithium battery, when the lithium battery expands or contracts, the stress is concentrated at the interface between the resin and metal bonding portion, and a peeling force is generated at the bonding portion. However, there was a problem that the sealing performance deteriorates due to destruction. The expansion or contraction of the lithium battery is caused by gas generation due to repeated charge / discharge, thermal expansion or contraction of the gas inside the battery due to temperature change, and the like.

Further, even when the lithium battery has a sealing mechanism using an O-ring, there has been a problem that the sealing performance is deteriorated due to concentration of stress due to expansion or contraction of the lithium battery.
JP 2002-237436 A

  The present invention has been made in view of the above circumstances, and is a battery container sealing plate that seals a lid and an electrode terminal with a sealing member, and has high sealing properties (high adhesive strength and It is an object to provide a sealing member that can ensure durability.

  In order to solve the above-mentioned problems, the present inventors have made studies, and as a result, have come to make the present invention.

  The sealing member of the present invention is arranged between a lid plate made of metal that forms a part of the battery container and has a through hole, an electrode terminal made of metal that penetrates the through hole, and the lid plate and the electrode terminal. A sealing member used for a sealing plate for a battery container having a non-reinforced polyphenylene sulfide resin bonded to at least one of an electrode terminal and a lid plate by a chemical bond. And the crystallinity of the resin is 35% or more.

  The seal member of the present invention is made of a crystalline polymer polyphenylene sulfide resin having a crystallinity of 35% or more, so that the seal member has high strength and water permeability. That is, the seal member of the present invention is a seal member having high sealing properties (high adhesive strength, durability, and water permeability).

  The sealing member of the present invention is provided between a lid plate made of metal that forms a part of a battery container and has a through hole, an electrode terminal made of metal that penetrates the through hole, and the lid plate and the electrode terminal. The sealing member is used for a battery container sealing plate having a sealing member in which a lid plate and an electrode terminal are joined by chemical bonding.

  The lid plate is a member that forms a part of the battery container and has a through hole. Here, the lid plate according to the present invention only needs to form a part for the battery container and be provided with a through hole. The battery container includes a bottomed cylindrical member and a member that closes the opening of the member. In this case, if the through hole is open, it may be a bottomed cylindrical member as well as a member that closes the opening. The sealing plate for battery devices of the present invention is more preferably a member that closes the opening of the bottomed cylindrical member. As the material constituting the lid plate, metal is used because of its high water permeability resistance. As a metal which comprises a cover plate, metals, such as aluminum, iron, stainless steel, can be mention | raise | lifted, for example.

  Further, the shape of the opening of the through hole opened in the cover plate is not particularly limited as long as the electrode terminal can be penetrated. It is preferable that the shape substantially coincides with the outer peripheral shape of the electrode terminal in the through hole. For example, the through-hole is preferably circular when the cross-sectional shape of the electrode terminal is cylindrical, and the through-hole is preferably square or oval when the electrode terminal is plate-shaped.

  The electrode terminal is a member disposed through the through hole. The electrode terminal is a member provided to take out the electric power generated in the electrode body that stores and discharges the electric power stored in the battery container to the outside of the battery container. As the electrode terminal, a conventionally known electrode terminal can be used. That is, the electrode terminal can be a metal formed in a rod shape or a plate shape.

  The seal member is a member disposed between the lid plate and the electrode terminal. That is, the sealing member ensures the sealing performance between the lid plate and the electrode terminal. The seal member electrically insulates the lid plate and the electrode terminal.

  The seal member of the present invention is made of a non-reinforced polyphenylene sulfide resin which is a crystalline polymer and has a crystallinity of 35% or more. The crystalline polymer is a polymer having a high ratio (crystallinity) of the amount (crystal region) in which molecular chains are regularly arranged (crystal region). In general, when the crystallinity of the crystalline polymer constituting the seal member decreases, the molecular chain becomes random, the water permeability increases (water permeability resistance decreases) and the tensile strength decreases (of the seal member). Strength decreases). The sealing member of the present invention is a sealing member having excellent sealing properties and water permeability resistance, because the crystallinity of the resin constituting the sealing member is 35% or more. That is, when the crystallinity is less than 35%, the water permeability of the seal member is lowered, and the strength of the seal member itself is also lowered, so that the sealing performance is lowered. In the sealing member of the present invention, the crystallinity of the polyphenylene sulfide resin is more preferably 35 to 60%. The upper limit of the degree of crystallinity inherent to polyphenylene sulfide resin is about 65%, but if the degree of crystallinity exceeds 60%, the brittleness increases and the strength of the seal member decreases against repeated stress due to increase / decrease in battery internal pressure or environmental temperature change. To do.

  The sealing member of the present invention may have a reinforcing material (filler) such as a fiber inside. However, since glass that is a generally usable reinforcing material is likely to react with the electrolyte of a nonaqueous electrolyte battery, it is preferably a sealing material that does not contain a reinforcing material (non-reinforced type). . That is, the crystalline polymer is preferably non-reinforced polyphenylene sulfide.

  Placing the electrode terminal and the cover plate in the mold, filling the mold with polyphenylene sulfide resin, which is a crystalline polymer, and placing the crystalline polymer between the electrode terminal and the cover plate; It is preferable to perform a heat treatment at a temperature higher than the recrystallization temperature of the conductive polymer. By performing the heat treatment, the crystallinity of the crystalline polymer can be set within a desired range, and stress remaining inside during molding can be eliminated by this heat treatment.

  The step of disposing the crystalline polymer is a step of filling the molding die with the crystalline polymer, and the crystalline polymer subjected to this step has a low degree of crystallinity because it is rapidly cooled from the molten state. . The method for filling the mold with the crystalline polymer is not particularly limited, and examples thereof include injection molding.

  In the heat treatment step, after heating above the recrystallization temperature, cooling (cooling, slow cooling) to a temperature lower than the recrystallization temperature (such as room temperature) is performed. That is, after heating to the recrystallization temperature or higher, it is cooled to the recrystallization temperature or lower, and by this cooling, the polyphenylene sulfide resin that is a crystalline polymer is crystallized to improve the crystallinity.

  The temperature at which the crystalline polymer is heated in the heat treatment step may be at least the recrystallization temperature of the crystalline polymer, and more preferably at least 1.05 times the crystallization temperature. If the heating temperature is too high, decomposition and melting occur, the shape of the sealing member changes, and sealing performance cannot be ensured. The heating temperature is preferably a temperature not higher than the melting temperature of the crystalline polymer, and more preferably not higher than 0.70 times the melting temperature.

  That is, the heat treatment is a heat treatment in which the recrystallization temperature of the crystalline polymer is Tc and the melting temperature is Tm, and the temperature is maintained at 1.05 × Tc to 0.7 × Tm for 0.5 hours or more. Preferably there is.

  When the amorphous polymer is non-reinforced polyphenylene sulfide, the heat treatment is preferably a treatment of holding at 130 to 200 ° C. for 0.5 hours or more.

  In the present invention, it is preferable that at least one of the electrode terminal and the cover plate and the sealing member are bonded by chemical bonding. Since the seal member is integrated with at least one of the electrode terminal and the cover plate, there is no gap between the seal member and the cover plate and / or the electrode terminal, and the sealing performance is further improved. Here, the term “integral” refers to a state in which both members form a chemical bond at the interface between the seal member and at least one of the electrode terminal and the cover plate.

  The method for integrating the cover plate and the seal member and / or the electrode terminal and the seal member is not particularly limited. For example, a metal lid plate and electrode terminals are subjected to surface treatment with triazine thiols or a silane coupling agent, and then a resin is insert-molded between the lid body and the electrode terminals, so that the sealing member, the electrode terminals, and the lid plate Can be integrated.

  The sealing member of the present invention is preferably used as a sealing member for a non-aqueous electrolyte battery. That is, the sealing member of the present invention is a sealing member with excellent sealing performance between the sealing member, the electrode terminal and the lid, and is a battery with excellent sealing performance when applied to a non-aqueous electrolyte battery. .

  The non-aqueous electrolyte battery can have the same configuration as a conventionally known non-aqueous electrolyte battery except for the sealing member described above. That is, an electrode body having a positive electrode and a negative electrode can be sealed in a battery container together with a non-aqueous electrolyte.

  The nonaqueous electrolyte battery is particularly preferably a lithium battery. The lithium battery may be a primary battery or a secondary battery, but the effect is particularly exerted in a secondary battery.

  A lithium battery includes a positive electrode and a negative electrode that can occlude and release lithium, and a nonaqueous electrolytic solution obtained by dissolving an electrolyte salt in a nonaqueous solvent.

  The positive electrode is not particularly limited in its material configuration as long as it can release lithium ions during charging and occlude during discharge, and may be a known material. In particular, it is preferable to use a material obtained by applying a mixture obtained by mixing a positive electrode active material, a conductive material, and a binder to a current collector.

The positive electrode active material is not particularly limited by the type of the active material, and a known active material can be used. For example, TiS ₂ , TiS ₃ , MoS ₃ , FeS ₂ , Li _(1-x) MnO ₂ , Li _(1-x) Mn ₂ O ₄ , Li _(1-x) CoO ₂ , Li _(1-x) NiO ₂ , compounds such as V ₂ O ₅ can be mentioned. Here, x shows 0-1. Moreover, you may use the mixture of these compounds as a positive electrode active material. Further, at least one or more other transition metal elements such as LiMn ₂ O ₄ and LiNiO ₂ such as Li _1-x Mn _{2 + x} O ₄ and LiNi _1-x Co _x O ₂ are used. Or what was replaced by Li is good also as a positive electrode active material.

As the positive electrode active material, lithium and transition metal composite oxides such as LiMn ₂ O ₄ , LiCoO ₂ , and LiNiO ₂ are more preferable. That is, since it has excellent performance as an active material such as excellent diffusion performance of electrons and lithium ions, a battery having high charge / discharge efficiency and good cycle characteristics can be obtained.

  The binder has an action of holding the active material particles. As the binder, an organic binder or an inorganic binder can be used, and examples thereof include compounds such as polyvinylidene fluoride (PVDF), polyvinylidene chloride, and polytetrafluoroethylene (PTFE). Can do.

  The conductive agent has an action of ensuring the electrical conductivity of the positive electrode. Examples of the conductive agent include one or a mixture of two or more carbon materials such as carbon black, acetylene black, and graphite.

  As the positive electrode current collector, for example, a metal such as aluminum or stainless steel that is processed into a net, a punched metal, a foam metal, or a plate can be used.

  The negative electrode is not particularly limited in its material configuration as long as lithium ions can be occluded during charging and released during discharging, and those having a known material configuration can be used. In particular, it is preferable to use a material obtained by applying a mixture obtained by mixing a negative electrode active material and a binder to a current collector.

  The negative electrode active material is not particularly limited, and a known active material can be used. For example, carbon materials such as highly crystalline natural graphite and artificial graphite, metal materials such as metallic lithium, lithium alloys, and tin compounds, conductive polymers, and the like can be given.

  The binder has an action of holding the active material particles. As the binder, an organic binder or an inorganic binder can be used, and examples thereof include compounds such as polyvinylidene fluoride (PVDF), polyvinylidene chloride, and polytetrafluoroethylene (PTFE). Can do.

  As the current collector for the negative electrode, for example, a foil obtained by processing copper, nickel or the like into a net, punched metal, foam metal, or plate shape can be used.

  The non-aqueous electrolyte may be an electrolyte used for a normal lithium secondary battery, and is composed of an electrolyte salt and a non-aqueous solvent.

Examples of the electrolyte salt include LiPF ₆ , LiBF ₄ , LiClO ₄ , LiAsF ₆ , LiCl, LiBr, LiCF ₃ SO ₃ , LiN (CF ₃ SO ₂ ) ₂ , LiC (CF ₃ SO ₂ ) ₃ , LiI, LiAlCl _4. , NaClO _4, NaBF _4, Nal, etc. can be mentioned, in _{particular, LiPF 6, LiBF 4, LiClO} 4, LiAsF inorganic lithium salt such as _{6, LiN (SO 2 C x} F 2x + 1) (SO 2 C y An organic lithium salt represented by F _{2y + 1} ) can be mentioned. Here, x and y represent an integer of 1 to 4, and x + y is 3 to 8. Specifically, as the organic lithium salt, LiN (SO ₂ CF ₃ ) (SO ₂ C ₂ F ₅ ), LiN (SO ₂ CF ₃ ) (SO ₂ C ₃ F ₇ ), LiN (SO ₂ CF ₃ ) (SO ₂ C ₄ F ₉ ), LiN (SO ₂ C ₂ F ₅ ) (SO ₂ C ₂ F ₅ ), LiN (SO ₂ C ₂ F ₅ ) (SO ₂ C ₃ F ₇ ), LiN (SO ₂ C ₂ F ₅ ) (SO ₂ C ₄ F ₉ ) and the like. Among them, it is preferable to use LiN (SO ₂ CF ₃ ) (SO ₂ C ₄ F ₉ ), LiN (SO ₂ C ₂ F ₅ ) (SO ₂ C ₂ F ₅ ) or the like as an electrolyte because it has excellent electrical characteristics.

  The organic solvent in which the electrolyte salt dissolves is not particularly limited as long as it is an organic solvent used in a non-aqueous electrolyte of a normal lithium secondary battery. For example, a carbonate compound, a lactone compound, an ether compound, a sulfolane compound, a dioxolane compound , Ketone compounds, nitrile compounds, halogenated hydrocarbon compounds and the like. Specifically, carbonates such as dimethyl carbonate, methyl ethyl carbonate, diethyl carbonate, ethylene carbonate, propylene carbonate, ethylene glycol dimethyl carbonate, propylene glycol dimethyl carbonate, ethylene glycol diethyl carbonate, vinylene carbonate, lactones such as γ-butyl lactone, Ethers such as dimethoxyethane, tetrahydrofuran, 2-methyltetrahydrofuran, tetrahydropyran, 1,4-dioxane, sulfolanes such as sulfolane and 3-methylsulfolane, dioxolanes such as 1,3-dioxolane, 4-methyl-2- Ketones such as pentanone, nitriles such as acetonitrile, pyropionitrile, valeronitrile, benzonitrile, 1,2-di Halogenated hydrocarbons such as Roroetan, other methyl formate, dimethylformamide, diethylformamide, and dimethyl sulfoxide and the like. Furthermore, a mixture thereof may be used.

  Among these organic solvents, one or more nonaqueous solvents selected from the group consisting of carbonates are particularly preferable because they are excellent in electrolyte solubility, dielectric constant, and viscosity.

  Further, in the battery container sealing plate of the present invention, the shape is not particularly limited, for example, a winding in which the positive electrode and the negative electrode are formed in a sheet shape and wound in a state via a sheet-shaped separator. For example, it is possible to use a substantially cylindrical shape that accommodates the mold electrode body or a square shape that accommodates the flat wound electrode body having a flattened shape.

  Hereinafter, the present invention will be described using examples.

  As an example of the present invention, a sealing plate for a lithium battery was produced.

(Example)
The sealing plate 1 for a lithium battery of this embodiment has a lid body 2, a positive electrode terminal 3, a negative electrode terminal 4, and an insulating sealing member 5. The sealing board 1 for lithium batteries of Example 1 was shown in FIGS.

  The lid body 2 is a flat plate member made of aluminum having a length of 100 mm × width of 20 mm × thickness of 0.8 mm and having two through holes 20 and 20 of 4 mm × 10 mm opened in the vicinity of both ends in the longitudinal direction. is there. The lid 2 is formed with convex aluminum ribs 21 having a width of 1 mm and a thickness of 1 mm at a position 2 mm from the openings of the through holes 20 and 20. That is, ribs having an inner peripheral surface of 8 mm × 14 mm are formed coaxially with the through holes 20 and 20 on the outer peripheral portions of the through holes 20 and 20. The rib 21 was formed by previously manufacturing an annular member with aluminum and integrally joining the lid body 2 by welding.

  The positive electrode terminal 3 is a flat plate member made of aluminum, and the negative electrode terminal 4 is a flat plate member made of copper.

  An insulating sealing member 5 (corresponding to a seal member) is provided between the lid 2 and the positive terminal 3 and between the lid 2 and the negative terminal 4. The lid 2 and the positive terminal 3, the lid 2 and the negative terminal Each of 4 is united. The insulating sealing member 5 is formed inside the ribs 21 and 21 of the lid 2. That is, the rib 21 is formed on the outer peripheral portion of the insulating sealing member 5.

  And the sealing board 1 for lithium batteries of a present Example was manufactured with the following method.

  First, with respect to the lid body 2, the positive electrode terminal 3, and the negative electrode terminal 4, the lid body 2, the positive electrode terminal 3 and the negative electrode terminal are obtained by using water or an organic solvent of a polyfunctional triazine dithiol derivative containing an electrolyte substance as necessary as an electrolytic solution. 4 as an anode and platinum, titanium, carbon, aluminum or stainless steel plate as a cathode, by electrochemical surface treatment methods such as cyclic method, constant current method, constant potential method, pulse constant potential method, pulse constant current method, etc. While the polyfunctional triazine dithiol derivative was primarily bonded in a molecularly oriented state, a film having high adhesion reactivity was generated on the surfaces of the lid body 2, the positive electrode terminal 3, and the negative electrode terminal 4. This method is a conventionally known method, and is disclosed, for example, in JP-A-10-237047.

  After producing the coating, the lid 2, the positive terminal 3 and the negative terminal 4 were placed in a 130 ° C. mold. At this time, the lid body 2, the positive electrode terminal 3, and the negative electrode terminal 4 are arranged in a through state with the positive electrode terminal 3 and the negative electrode terminal 4 not contacting the lid body 2 in the respective through holes 20, 20 of the lid body 2. It was. Then, the polyphenylene sulfide composition melted at about 300 ° C. was filled into the mold and cooled and solidified. Here, the recrystallization temperature of the polyphenylene sulfide composition is about 120 ° C., and the melting temperature is about 280 ° C. The polyphenylene sulfide composition is a non-reinforced type that does not contain a reinforcing material.

  Thereafter, the sealing plate in which the electrode terminals 2 and 4 were joined to the lid 2 with the insulating sealing member 5 was subjected to a heat treatment for heating at a temperature of 130 ° C. for 1 hour.

  Thereby, the sealing plate 1 for lithium batteries in which the insulating sealing member 5 chemically bonded to the cover 2 and the coating on the surface of the electrode terminals 3 and 4 was formed was manufactured.

  The crystallinity of the insulating sealing member 5 of the manufactured lithium battery sealing plate 1 was measured and found to be 35%. The measurement of crystallinity is obtained by detecting an exothermic peak due to resin recrystallization during temperature rise using a differential calorimeter.

(Comparative Example 1)
This is a sealing plate for a lithium battery produced in the same manner as in the Examples except that the final heat treatment was not applied.

  When the degree of crystallinity of the insulating sealing member 5 of this comparative example was measured in the same manner as in the example, it was 20%.

(Comparative Example 2)
A sealing plate for a lithium battery produced in the same manner as in the example except that the last heat treatment is a heat treatment at 100 ° C. for 1 hour.

  The crystallinity of the insulating sealing member 5 of this comparative example was measured in the same manner as in the example and found to be 26%.

(Evaluation)
With respect to the battery lid 1 of Examples and Comparative Examples 1 and 2, a pullout test of the positive electrode terminal 3 and the negative electrode terminal 4 was performed to measure the bonding strength. The measurement results are shown in Table 1. In addition, the joint strength in the drawing refers to the maximum strength value until the joint between the electrode terminal portion and the sealing member is damaged, and the maximum strength in the stress strain curve at the time of measurement is used.

  Moreover, the electrolyte solution was filled in the tank-shaped container which consists of aluminum, and it sealed by the battery cover body 1 of the Example and Comparative Examples 1-2 after that. The battery can 1 was sealed by welding. Then, after being left in an environment of 65 ° C. and 95% RH, the amount of increase in the water content in the internal electrolyte was measured by the Karl Fischer method to determine the water permeability per 24 hours. The results are shown in Table 1.

As shown in Table 1, the battery lid 1 of the example has a high pulling strength (bonding strength) of 35 MPa. This strength is a value close to the strength of a substantial resin and is a considerably high value. Further, the battery lid 1 of the example also has a water permeability per 24 hours of 0.45 g / m ^{2 which} is a considerably low value. That is, it can be seen that the insulating sealing member 5 of the battery lid 1 of the example is excellent in sealing properties and water permeability resistance.

  On the other hand, the battery lids of Comparative Examples 1 and 2 had low pullout strength and high water permeability per 24 hours. That is, it can be seen that the insulating sealing member 5 of the battery lid of each comparative example has low sealing properties and water resistance.

  The battery lid 1 of the above-described embodiment can form, for example, the lithium secondary battery shown below.

  The lithium secondary battery has a flat wound electrode body 7 formed in a flat shape in a state where a belt-like positive electrode plate 70, a negative electrode plate 71, and a separator 72 interposed between the two electrode plates 70 and 71 are wound. And the positive electrode terminal 3 and the negative electrode terminal 4 joined to the flat wound electrode body 7, a tank-shaped container body 6 that houses the flat wound electrode body 7, and an electrolytic solution.

The positive electrode plate 70 has a positive electrode active material layer formed on both surfaces of a positive electrode current collector made of a strip-shaped aluminum sheet, and a positive electrode active material layer formed on one end side in the width direction of the positive electrode current collector. Has no edge. LiNiO ₂ was used as the positive electrode active material.

  The negative electrode plate 71 has a negative electrode active material layer 711 formed on both sides of a negative electrode current collector made of a strip-shaped copper sheet, and a negative electrode active material layer formed on one end side in the width direction of the negative electrode current collector. It has a marginal edge. Carbon was used for the negative electrode active material.

  The separator 72 is made of polyethylene or polypropylene formed in a band shape. The separator 72 is formed to have a longer band width than the region where the electrode active material layers of the bipolar plates 70 and 71 are formed, and also longer than the bipolar plates 70 and 71.

  In the flat wound electrode body 7, the edge portions of the positive electrode plate 70 and the negative electrode plate 71 protrude from the separator 72 in directions opposite to each other in the axial direction to form a positive electrode side protruding end portion 700 and a negative electrode side protruding end portion 710. Yes. The protruding end portions 700 and 710 are formed to be joined to each other in a state where the edge portions are stacked. The positive electrode side protruding end portion 700 was joined to the positive electrode terminal 3 and the negative electrode side protruding end portion 710 was joined to the negative electrode terminal 4 by welding. The projecting end portions 700 and 710 are joined to surfaces facing each other, with the end surfaces of the winding shafts being the end portions of the electrode terminals 3 and 4 on the housing inner side.

As the electrolytic solution, a solution in which 1 mol of LiPF ₆ was added to a mixed solvent in which ethylene carbonate and diethylene carbonate were mixed at a ratio of 3: 7 was used.

  In the lithium secondary battery, after forming the flat wound electrode body 7 in which the positive electrode plate 70 and the negative electrode plate 71 are wound through the separator 72, the protruding end portions 700 of the flat wound electrode body 7 are formed. After the positive electrode terminal 3 and the negative electrode terminal 4 are welded to 710, they are inserted into the container body 6 made of aluminum together with the electrolytic solution, and the container body 6 and the lithium battery sealing plate 1 are welded and sealed. It was. The manufactured lithium battery is shown in FIG.

It is the figure which showed the sealing board for lithium batteries of the Example. It is the figure which showed the cover plate of the sealing board for lithium batteries of an Example. It is sectional drawing of the sealing board for lithium batteries of an Example. It is the figure which showed the structure of the lithium battery using the sealing board for lithium batteries of an Example.

Explanation of symbols

1: Lithium battery sealing plate 2: Lid 20: Through hole 21: Rib 3: Positive electrode terminal 4: Negative electrode terminal 5: Insulating sealing member 6: Container body 7: Electrode body 70: Positive electrode plate 71: Negative electrode plate 72: Separator

Claims (3)

A cover plate made of metal that forms part of the battery container and has a through hole;
An electrode terminal made of metal penetrating the through hole;
A sealing member disposed between the lid plate and the electrode terminal;
A sealing member used for a battery container sealing plate having
The sealing member is a non-reinforced polyphenylene sulfide resin bonded to at least one of the electrode terminal and the lid plate by a chemical bond, and the crystallinity of the resin is 35% or more. Seal member. Placing the electrode terminal and the lid plate in a mold;
Filling the crystalline polymer in the mold and placing and molding the resin between the electrode terminal and the cover plate;
Heat treatment at a temperature equal to or higher than the recrystallization temperature of the resin;
The sealing member according to claim 1, wherein   The sealing member according to claim 2, wherein the heat treatment is performed at a temperature of 1.05 × Tc to 0.7 × Tm, where Tc is a recrystallization temperature of the crystalline polymer and Tm is a melting temperature.

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