Method for manufacturing tab lead, tab lead, electrochemical device, battery, and capacitor

Abstract

To provide a method for manufacturing a tab lead capable of improving sealability in an electrochemical device, the tab lead, the electrochemical device, a battery, and a capacitor.SOLUTION: Provided is a method for manufacturing a tab lead having a lead conductor comprising a first main surface and a second main surface opposite to the first main surface, and a resin part covering the first main surface, the second main surface, and both side surfaces between both ends of the lead conductor while exposing both ends of the lead conductor. In the method, a step of forming the resin part includes filling a mold with a thermosetting composition.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a method for manufacturing a tab lead, a tab lead, an electrochemical device, a battery, and a capacitor. Specifically, the present invention relates to a method for manufacturing a tab lead, a tab lead, an electrochemical device, a battery, and a capacitor that can improve the hermeticity in an electrochemical device.

Background Art

[0002] There is known a battery having a structure in which a positive electrode, a negative electrode, an electrolytic solution, etc. are enclosed in a packaging material, and lead wires are connected to each of the positive electrode and the negative electrode (Patent Documents 1 and 2). A part of the lead wire is taken out from the packaging material. This lead wire is called a tab lead and has a structure in which a sealing material formed of two thermoplastic resin films (sealant films) bonded to each other so as to sandwich the lead conductor is disposed in a part of the lead conductor region. In a battery, the sealing material is disposed so as to seal the gap between the packaging material and the lead conductor.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in conventional technologies including Patent Documents 1 and 2, room for further improvement has been found from the viewpoint of improving the hermeticity in electrochemical devices such as batteries.

[0005] One object of the present invention is to provide a method for manufacturing a tab lead, a tab lead, an electrochemical device, a battery, and a capacitor that can improve the hermeticity in an electrochemical device.

Means for Solving the Problem

[0006] As a result of intensive studies, the present inventors have found that the hermeticity in an electrochemical device can be improved by applying a thermosetting resin to the resin portion in a tab lead, and have completed the present invention. According to the present invention, the following method for manufacturing a tab lead and the like can be provided. 1. A method for manufacturing a tab lead having a lead conductor including a first main surface and a second main surface opposite to the first main surface, and a resin portion covering the first main surface, the second main surface, and both side surfaces between both ends of the lead conductor while exposing both ends of the lead conductor, wherein the step of forming the resin portion includes filling a mold with a thermosetting composition. 2. The method according to 1, wherein the thermosetting composition includes (A) a di(meth)acrylate compound having a structural unit represented by the following formula (A1), or a compound represented by the following formula (A2) or (A3), and (B) a thermal polymerization initiator.

Chemical Formula

Chemical Formula

Chemical formula

Chemical formula

Chemical formula

Chemical formula

Advantages of the Invention

[0007] According to the present invention, it is possible to provide a method for manufacturing a tab lid capable of improving the sealing property in an electrochemical device, a tab lid, an electrochemical device, a battery, and a capacitor.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Embodiments for Carrying Out the Invention

[0009] Hereinafter, the method for manufacturing a tab lead, the tab lead, the electrochemical device, the battery, and the capacitor according to the present invention will be described in detail. In addition, in this specification, "x to y" shall represent a numerical range of "x or more and y or less". The upper limit value and the lower limit value described for the numerical range can be arbitrarily combined. Also, among the individual embodiments of the aspects according to the present invention described below, those that are not mutually contradictory can be combined in two or more, and the embodiments obtained by combining two or more embodiments are also embodiments of the aspects according to the present invention.

[0010] In this specification, in the expression "substituted or unsubstituted ZZ group having XX to YY carbon atoms", "XX to YY carbon atoms" represents the number of carbon atoms when the ZZ group is unsubstituted, and does not include the number of carbon atoms of the substituent when it is substituted. Here, "YY" is larger than "XX", and "XX" and "YY" each mean an integer of 1 or more.

[0011] In this specification, in the expression "substituted or unsubstituted ZZ group having XX to YY atoms", "XX to YY atoms" represents the number of atoms when the ZZ group is unsubstituted, and does not include the number of atoms of the substituent when it is substituted. Here, "YY" is larger than "XX", and "XX" and "YY" each mean an integer of 1 or more.

[0012] In this specification, as the substituent (hereinafter, also referred to as an arbitrary substituent) in the case of "substituted or unsubstituted", for example, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a halogen atom, a hydroxyl group, an oxirane group, a methacryloyloxy group, an acryloyloxy group, -O-(R 901 )、-S-(R 902 )、-N(R 903 )(R 904) etc. may be mentioned. R 901 ~R 904 is each independently a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. Examples of the alkyl group having 1 to 6 carbon atoms (preferably linear or branched) include a methyl group, an ethyl group, a propyl group (e.g., n-propyl group, isopropyl group), a butyl group (e.g., n-butyl group, isobutyl group, s-butyl group, t-butyl group), a pentyl group (e.g., n-pentyl), a hexyl group, and the like. Examples of the alkoxy group having 1 to 6 carbon atoms include a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentyloxy group, a hexyloxy group, and the like. Examples of the halogen atom include a fluorine atom, a bromine atom, an iodine atom, and the like.

[0013] In the case of "unsubstituted or substituted", "unsubstituted" means not substituted with the above-mentioned substituents and having a hydrogen atom bonded thereto.

[0014] In this specification, acrylate and methacrylate are collectively referred to as (meth)acrylate. Acrylic acid and methacrylic acid are collectively referred to as (meth)acrylic acid. Acrylo and methacrylo are collectively referred to as (meth)acrylo. Acrylic and methacrylic are collectively referred to as (meth)acrylic. Methacryloyl group and acryloyl group are collectively referred to as (meth)acryloyl group.

[0015] 1. Method for manufacturing a tab lead The method for manufacturing a tab lead according to one aspect of the present invention is a method for manufacturing a tab lead having a lead conductor having a first main surface and a second main surface opposite to the first main surface, and a resin portion covering the first main surface, the second main surface, and both side surfaces between both ends of the lead conductor while exposing both ends of the lead conductor, wherein the step of forming the resin portion includes filling a thermosetting composition into a mold. According to this aspect, a tab lead capable of improving the sealing property in an electrochemical device can be manufactured.

[0016] FIG. 1 is a plan view showing an example of a tab lead manufactured according to this aspect. FIG. 2 is a cross-sectional view taken along line (ii)-(ii) in FIG. 1. The tab lead 1 shown in FIGS. 1 and 2 has a lead conductor 2 and a resin part 3. The lead conductor 2 includes a first main surface 2a and a second main surface 2b opposite to the first main surface 2a. The planar shape of the lead conductor 2 is not limited to a rectangle as shown in the figure, and various planar shapes can be given according to the purpose and application. The resin part 3 covers the first main surface 2a, the second main surface 2b, and both side surfaces 2c between both end portions of the lead conductor 2 in the vertical direction in FIG. 1 while exposing both end portions. The planar shape of the resin part 3 is not limited to a rectangle as shown in the figure, and various planar shapes can be given according to the purpose and application. Both end portions of the lead conductor 2 are in a state of being exposed without the formation of the resin part 3 because they are electrically connected to conductive parts such as electrodes and terminals. In an electrochemical device (not shown), the resin part 3 is arranged so as to seal the gap between the packaging material in which the positive electrode, negative electrode, electrolyte, etc. are enclosed and the lead conductor 2.

[0017] In this aspect, when manufacturing the tab lead 1 as described above, the step of forming the resin part 3 includes filling a thermosetting composition into a mold, thereby obtaining an effect of improving the sealing property in the electrochemical device. Regarding this point, as a comparison, the conventional technology will be described with reference to FIG. 3. In the conventional technology, a resin part (sealing material) is formed by two thermoplastic resin films (sealant films) 4 and 5 that are bonded to each other so as to sandwich the lead conductor 2. In this case, it is particularly difficult to bring both side surfaces 2c of the lead conductor 2 into close contact with the thermoplastic resin films 4 and 5, and gaps are likely to occur. In order to prevent the occurrence of such gaps, it is conceivable to form the thermoplastic resin films 4 and 5 thick, but there is a limit because the thickness of the entire battery also increases. For convenience of explanation, in FIG. 3, the thermoplastic resin films 4 and 5 are each shown in a single-layer structure, but in reality, a laminated structure having three or more layers is usually adopted. In contrast, in the present aspect, since the thermosetting composition (the material for forming the resin portion 3) filled in the mold has fluidity in the state before curing, the molding accuracy by the mold can be improved. Therefore, the resin portion 3 can be molded to conform to the shape of the lead conductor 2 with high precision. As a result, as shown in FIG. 2, the resin portion 3 can be formed so as to adhere well to both side surfaces 2c of the lead conductor 2. Thereby, the hermeticity in the electrochemical device can be improved. Such an effect is exhibited well regardless of the thickness of the resin portion 3, for example, even when the resin portion 3 is formed thinly. Therefore, effects such as weight reduction of the battery and size reduction (low volume) can also be obtained. Further, according to the present aspect, an effect of reducing the number of steps in manufacturing the tab lead 1 can be obtained as compared with the conventional technology.

[0018] The material of the lead conductor 2 is not particularly limited as long as it is a conductor. In one embodiment, the lead conductor 2 is made of metal. In one embodiment, the lead conductor 2 is made of aluminum (Al), nickel (Ni), an aluminum alloy, a nickel alloy, nickel-plated copper, or nickel-clad copper. In one embodiment, when the electrochemical device is a lithium ion battery or a lithium ion capacitor, aluminum or an aluminum alloy is used for the lead conductor 2 on the positive electrode side, and nickel, a nickel alloy, or nickel-plated copper is used for the lead conductor 2 on the negative electrode side. The surface of the lead conductor 2 may or may not be subjected to a surface treatment (for example, chromate treatment, etc.) for the purpose of enhancing adhesiveness or the like.

[0019] The thickness of the lead conductor 2 is not particularly limited. In one embodiment, the thickness of the lead conductor 2 is 0.05 to 1.5 mm. The lead conductor 2 can be obtained, for example, by cutting a metal foil into a predetermined size.

[0020] The resin part 3 is arranged to cover the outer peripheral side of a partial area, excluding the areas including both upper and lower end parts of the lead conductor 2 in the vertical direction in FIG. 1. As shown in FIG. 2, the resin part 3 is formed in an annular shape so as to surround the outer peripheral side of the lead conductor 2. The inner peripheral side of the resin part 3 is in direct contact with the lead conductor 2 over the whole thereof.

[0021] In one embodiment, the thickness of the resin part 3 on the first main surface 2a of the lead conductor 2 and / or the thickness of the resin part 3 on the second main surface 2b of the lead conductor 2 is 10 μm or more, 20 μm or more, 30 μm or more, 40 μm or more, 50 μm or more, 60 μm or more, 70 μm or more, 80 μm or more, 90 μm or more or 100 μm or more, and is 300 μm or less, 250 μm or less or 200 μm or less. Also, as described above, in this aspect, even when the resin part 3 is formed thinly, the sealing property in the electrochemical device can be improved well. By forming the resin part 3 thinly, effects such as weight reduction of the electrochemical device and size reduction (low volume) can be obtained. From such a viewpoint, in one embodiment, the thickness of the resin part 3 on the first main surface 2a of the lead conductor 2 and / or the thickness of the resin part 3 on the second main surface 2b of the lead conductor 2 is 100 μm or less, 90 μm or less, 80 μm or less, 70 μm or less, 60 μm or less or 50 μm or less.

[0022] In one embodiment, the composition of the resin part 3 is uniform over the whole of the resin part 3. Since the resin part 3 is manufactured using a mold, it usually does not have a laminated structure like the conventional technology.

[0023] In one embodiment, the thermosetting composition contains a thermosetting resin. Examples of the thermosetting resin include acrylic resin, phenolic resin, epoxy resin, unsaturated polyester resin, melamine resin, and polyurethane. These may be used alone or in combination of two or more. In one embodiment, the thermosetting composition contains an acrylic resin as the thermosetting resin. In one embodiment, the thermosetting composition includes a thermosetting resin and a thermal polymerization initiator. The thermal polymerization initiator can be appropriately selected according to the type of the thermosetting resin used and the like. In addition, the "thermosetting resin" contained in the thermosetting composition filled in the mold is in an uncured state or a state where curing is not complete.

[0024] Hereinafter, an example of a preferable thermosetting composition (also referred to as "thermosetting composition α") will be described. Regarding the thermosetting composition α, reference can be made to the thermosetting compositions for injection molding described in Japanese Patent Application No. 2023-513034 and Japanese Patent Application No. 2023-513037.

[0025] In one embodiment, the thermosetting composition α is (A) a di(meth)acrylate compound having a structural unit represented by the following formula (A1), or a compound represented by the following formula (A2) or (A3), and (B) a thermal polymerization initiator.

[0026]

Chemical formula

[0027] (In formula (A1), V 101 is a divalent aromatic hydrocarbon group having 6 to 12 ring-forming carbon atoms which may be substituted or unsubstituted, a divalent alicyclic hydrocarbon group having 5 to 12 ring-forming carbon atoms which may be substituted or unsubstituted, or a divalent aliphatic hydrocarbon group having 2 to 30 carbon atoms which may be substituted or unsubstituted. p represents the average number of constitutional units. When p is 2 or more, two or more Vs 101 may be the same as or different from each other.)

[0028]

Chemical formula

[0029] (In formula (A2), R 111 and R115 Each is independently a hydrogen atom or a methyl group. R 112 is an alkylene group having 1 to 20 carbon atoms. R 113 and R 114 are each independently an alkylene group having 1 to 30 carbon atoms. n 112 represents an integer of 0 or 1. n 113 represents an integer of 0 to 30.)

[0030]

Chemical formula

[0031] (In formula (A3), R 121 is an alkylene group having 1 to 6 carbon atoms. R 122 is a hydrogen atom or a methyl group. n 120 is 3 or 4. n 121 represents an integer of 0 to 15. n 120 When n is 3, Z 120 is a substituted or unsubstituted trivalent aliphatic hydrocarbon group having 3 to 10 carbon atoms. n 120 When n is 4, Z 120 is a substituted or unsubstituted tetravalent aliphatic hydrocarbon group having 5 to 10 carbon atoms.)

[0032] In one embodiment, the viscosity of component (A) measured at 25 °C at a shear rate of 10 s -1 is 0.001 Pa·s or more and 80 Pa·s or less based on JIS K7117-2.

[0033] The thermal polymerization initiator of component (A) refers to a compound that generates active species such as radicals and cations by heating. By including the thermal polymerization initiator in component (B), a stable molded product can be obtained (for example, the curing time can be shortened and the margin of the curing time can be narrowed). Component (B) is not particularly limited, and examples thereof include radical polymerization initiators. The radical polymerization initiator is not particularly limited, and examples thereof include ketone peroxides, hydroperoxides, diacyl peroxides, dialkyl peroxides, peroxyketals, alkyl peresters (peroxy esters), peroxy carbonates, and the like.

[0034] Based on 100 parts by mass of the total of the components other than component (B), the content of component (B) is preferably 0.01 to 10 parts by mass, more preferably 0.1 to 5 parts by mass, and even more preferably 0.1 to 3 parts by mass.

[0035] In one embodiment, the thermosetting composition α further comprises (C) a compound represented by the following formula (C1), and a polymer containing at least one structural unit represented by the following formula (C2) and at least one structural unit represented by the following formula (C3) and includes one or more selected from the group consisting of.

[0036]

Chemical formula

[0037] (In formula (C1), Y 301 、Y 302 、and Y 303 each independently represents an alkylene group having 1 to 10 carbon atoms substituted with a hydroxy group, or an alkylene group having 1 to 10 carbon atoms. X 301 and X 302 each independently represents an alkylene group having 1 to 10 carbon atoms, or an alkylene group having 1 to 10 carbon atoms substituted with a hydroxy group. Z represents -Z 301 -Z 302 -Z 303 -, or -Z 304 -Z 305 -Z 306 -. R 301 and R302 Each independently represents a hydrogen atom or a methyl group. Z 301 and Z 303 Each independently represents a substituted or unsubstituted divalent aromatic hydrocarbon group having 6 to 12 ring-forming carbon atoms, or a substituted or unsubstituted divalent alicyclic hydrocarbon group having 6 to 12 ring-forming carbon atoms. Z 302 represents -C(CH3)2-, -C(CF3)2-, -CH2-, -S(=O)2-, -O- or -C(=O)-. Z 304 and Z 306 Each independently represents a divalent organic group. Z 305 represents a substituted or unsubstituted divalent fluorene or a substituted or unsubstituted divalent naphthalene. a and b each independently represent an integer from 0 to 10. c, d and e each independently represent 0 or 1. f represents an integer from 1 to 5. a + (b × f) + c + d + (e × f) is 2 or more. )

[0038]

Chemical formula

[0039] (In formula (C2), R 401 is a hydrogen atom or a methyl group. In formula (C3), R 402 is a hydrogen atom or a methyl group. R 403 is an alkyl group having 2 to 18 carbon atoms, -R 411 OR 412 , or -R 413 SR 414 is. R 411 and R 413 Each independently is an alkylene group having 1 to 30 carbon atoms. R 412 and R 414 Each independently is an alkyl group having 1 to 30 carbon atoms. )

[0040] In one embodiment, component (C) includes a polymer containing at least one structural unit represented by formula (C2) and at least one structural unit represented by formula (C3). In one embodiment, the polymer containing at least one structural unit represented by formula (C2) and at least one structural unit represented by formula (C3) is a block copolymer. In one embodiment, component (C) includes a compound represented by formula (C1).

[0041] In one embodiment, in the thermosetting composition α, based on 100% by mass of the total of components other than component (B), the content of component (C) is 5% by mass or more and 50% by mass or less.

[0042] In one embodiment, the thermosetting composition α further includes (D) a compound represented by the following formula (D1).

[0043]

Chemical formula

[0044] From the viewpoint of further improving the adhesion between the resin part 3 and the lead conductor 2 and the adhesion between the resin part 3 and the packaging material, component (D) preferably includes an acrylate compound or a methacrylate compound having a glycidyl group.

[0045] When component (D) is contained, the content of component (D) is preferably 1 to 80% by mass, more preferably 10 to 60% by mass, based on 100% by mass of the total of components other than component (B).

[0046] In one embodiment, the thermosetting composition α may further contain an inorganic filler as component (E). Thereby, the flame retardancy can be improved. Component (E) is preferably at least one selected from the group consisting of magnesium hydroxide and aluminum hydroxide, and more preferably aluminum hydroxide.

[0047] In one embodiment, the thermosetting composition α may further contain a phosphate ester flame retardant as component (F). Thereby, the flame retardancy can be improved.

[0048] In one embodiment, the thermosetting composition α may further contain additives as long as the effects of the present invention are not inhibited. Examples of the additives include antioxidants, light stabilizers, flame retardants other than phosphate ester flame retardants, ultraviolet absorbers, plasticizers, colorants, antistatic agents, lubricants, mold release agents, leveling agents, defoaming agents, and the like. Known ones of these additives can be used.

[0049] In one embodiment, the thermosetting composition α essentially consists of component (A) and component (B), and optionally components (C) to (F) and additives, and may contain other inevitable impurities as long as the effects of the present invention are not impaired. In one embodiment, for example, 40% by weight or more, 95% by weight or more, or 99% by weight or more or 100% by mass of the thermosetting composition α is component (A) and component (B), components (A) to (D), components (A) to (F), or may consist of component (A) and component (B), and optionally components (C) to (F) and additives.

[0050] In one embodiment, the thermosetting composition α has a viscosity at a shear rate of 10 s at 25°C measured based on JIS K7117-2 -1 of 0.001 Pa·s or more and 600 Pa·s or less.

[0051] Next, an example of the process for forming the resin portion 3 will be described. In one embodiment, the process of forming the resin part 3 includes a process of supplying a thermosetting composition into a plunger (supply process), a process of filling the supplied thermosetting composition into a molded part (cavity) of a mold having a molded part with a gauge pressure of -90 kPa or less (vacuum pressure 10 kPa), an oxygen amount of 0.2 × cavity volume / 22.4 mol or less, or a gauge pressure of -90 kPa or less (vacuum pressure 10 kPa) and an oxygen amount of 0.2 × cavity volume / 22.4 mol or less by the plunger (filling process), and a process of thermosetting the filled thermosetting composition in the molded part (curing process). The process of forming the resin part 3 may further include a process of extruding the thermoset thermosetting resin from the molded part (cavity) (demolding process).

[0052] As a molding method, from the viewpoint of preventing only the resin component in the thermosetting composition from being filled, transfer molding such as LTM (Liquid Transfer Molding) molding, compression molding, or injection molding such as LIM molding (Liquid Injection Molding) is preferable. Preliminary polymerization may be performed.

[0053] In transfer molding, using a transfer molding machine (for example, liquid transfer molding machine G-Line), for example, it can be molded at a clamping force of 5 to 20 kN, a molding temperature of 60 to 190 °C for a molding time of 30 to 500 seconds, preferably at a molding temperature of 70 to 180 °C for a molding time of 30 to 180 seconds. Post-curing may be performed, for example, at 150 to 185 °C for 0.5 to 24 hours.

[0054] In liquid injection molding, using, for example, a liquid thermosetting resin injection molding machine LA-40S, for example, it can be molded at a clamping force of 10 kN to 40 kN, a molding temperature of 60 to 190 °C for a molding time of 30 to 500 seconds, preferably at a molding temperature of 70 to 180 °C for a molding time of 20 to 180 seconds.

[0055] The above-mentioned molding machine preferably includes a plunger and a mold having a molded product portion. The above-mentioned molding machine preferably further includes a shut-off nozzle.

[0056] FIG. 4 is a diagram showing an embodiment of a filling device of a molding machine capable of implementing an injection molding method. The molding machine of FIG. 4 is an injection molding machine having a plunger mechanism for extruding a thermosetting composition into a mold, and includes a filling device 10 having a plunger 11 shown in FIG. 4 and a mold 20 having a cavity 21 shown in FIG. 5(A). Although not shown, it includes a decompression device as a degassing means connected to pores for degassing the cavity 21 in the mold 20, a heating device as a heating means connected to the mold 20, and a cooling device. The molding material is a thermosetting composition. As another embodiment, the molding machine may include an inert gas replacement device as a means connected to pores for replacing the cavity in the mold with an inert gas.

[0057] As the filling device 10, a filling device having a known plunger can be used. Usually, as shown in FIG. 4, the filling device 10 having a plunger 11 has a feed portion and a backflow prevention function, and by moving the backflow prevention valve 12 (the backflow prevention valve may be in a screw shape), the material introduced from an inlet (not shown) is fed, stirred, and mixed. However, in this embodiment, since a thermosetting composition which is a uniform liquid is introduced, stirring and mixing may not be necessary.

[0058] In the step of filling the cavity with the plunger, it is preferable to fill the cavity in the mold with the thermosetting composition through a flow path whose temperature is controlled to 50°C or lower. When implemented using the device shown in FIG. 5, the above-mentioned flow path corresponds to the flow path of the thermosetting composition in the filling device 10 (not shown) and the introduction path in the mold 20.

[0059] In one embodiment, in the step of filling the thermosetting composition filled in the plunger into the cavity in the mold by the plunger, a gate system is provided in the flow path (flow channel) portion between the plunger and the cavity to block the flow of the curing liquid and the transfer of heat. Hereinafter, it will be described with reference to FIG. 5. When using the apparatus shown in FIG. 5, for example, the needle 223 and the opening 222 correspond to the above gate system. As described above, when the needle 223 moves to the side of the movable mold 23 and closes the opening 222, the introduction path 221 is divided in front of the heating portion 22A, and the thermosetting composition introduced into the introduction path 221 stays in the cooling portion 22B, and the flow of the thermosetting composition and the transfer of heat can be blocked. As a system capable of blocking the flow of the thermosetting composition and the transfer of heat, there are a valve gate system, a shut-off nozzle system, and the like. The heating device is a device that heats the heating portion 22A and the movable mold 23. By heating these, the temperature in the cavity (also referred to as "cavity temperature") can be set to a predetermined temperature. Preferably, the temperature of the mold 232 constituting the cavity portion is 40 ° C or higher and 150 ° C or lower. The cooling device is a device that cools the flow path of the thermosetting composition. Specifically, it is preferable to cool the filling device 10 and the cooling portion 22B of the mold 20 to 10 ° C or higher and 50 ° C or lower. In the case of injection molding, the needle (not shown) in FIG. 4 corresponds to the needle 223 in FIG. 5, and the flow path (not shown) in FIG. 4 corresponds to the introduction path 221 in FIG. 5.

[0060] The supply process is shown in FIG. 4. In the case of transfer molding or compression molding, for example, a supply device (not shown) such as a syringe can be used to insert an appropriate amount of material into the plunger 11 for weighing. In the case of injection molding, the thermosetting composition is injected from an inlet (not shown) into the filling device 10 shown in Fig. 4. The injected thermosetting composition is pushed out by the check valve 12, and then a predetermined amount is measured by the plunger 11. After the measurement is completed or before injection, the check valve 12 advances and functions as a check valve when the plunger 11 operates. During this period, since the flow path is cooled by the cooling device, the thermosetting composition flows smoothly without curing.

[0061] The filling process is shown, for example, in Fig. 5(B). When injecting the thermosetting composition into the cavity, it is preferable to install a vent for discharging the air in the cavity or to provide pores connected to a decompression device such as the decompression tube 240 in Fig. 5 to enable decompression of the cavity, so as to decompress the cavity. The reason is that during the process of injecting the thermosetting composition into the cavity and completely filling it, the vent discharges the air in the cavity, and cavity decompression makes the cavity airless, so that the cavity can be completely filled with the thermosetting composition. If there is no such mechanism, it is preferable to have a mechanism that allows the air in the cavity to escape during material filling (for example, a vent mechanism). From the perspective of preventing poor curing, the gauge pressure in the cavity when injecting the thermosetting composition into the cavity is preferably -90 kPa or less (vacuum pressure 10 kPa), the amount of oxygen in the cavity is 0.2 × cavity volume / 22.4 mol or less, or -90 kPa or less (vacuum pressure 10 kPa), and the amount of oxygen in the cavity is 0.2 × cavity volume / 22.4 mol or less. A preferred method for making the amount of oxygen in the cavity 0.2 × cavity volume / 22.4 mol or less is by degassing with a decompression device connected to pores for degassing the cavity in the mold and replacing with an inert gas using an inert gas replacement device connected to pores for replacing the cavity in the mold with an inert gas. Also, the method of decompressing the cavity is preferably sprue-less. To mold the thermosetting composition, first, the movable mold 23 is brought close to the fixed mold 22 and clamping is performed (Fig. 5(A)). The movement of the movable mold 23 is temporarily stopped at the position where the elastic member 238 of the movable mold 23 contacts the elastic member 224 of the fixed mold 22.

[0062] Filling the cavity with the thermosetting composition is preferably carried out by opening the gate of the gate system (moving the needle 223 to the fixed mold 22 side) and filling the cavity 21 in the mold with the thermosetting composition. The heating parts 22A provided in the movable mold 23 and the fixed mold 22 are constantly heated, and the cavity temperature is set to be, for example, 50°C or higher, preferably 50°C or higher and 150°C or lower, particularly preferably 50°C or higher and 120°C or lower. In addition, when using an injection molding machine, when starting the injection from the injection part to the cavity, the nozzle of the shut-off nozzle (or valve gate in some cases) is opened, the plunger of the injection part is moved, and the thermosetting component is injected into the cavity. When using a transfer molding machine, since the entire part from inside the plunger to the cavity part is cured, it is only necessary that the material can flow into the cavity, and it is not necessary to block the heat transfer.

[0063] The curing process is shown, for example, in Fig. 5(C). When the filling of the thermosetting composition into the cavity 21 is completed, the curing of the thermosetting composition starts simultaneously. However, in order to improve the transferability of the molded product, it is preferable to cure by applying a predetermined pressure. That is, it is preferable that the plunger 11 is in a state of being pressurized to 1.0 MPa or higher and 30 MPa or lower. To improve the transferability, this pressure applied to the thermosetting composition is called the holding pressure. The curing process preferably involves applying pressure (increasing the pressure applied to the thermosetting composition) after the start of thermal curing and before the completion of curing. After applying the pressure, the gate of the gate system is closed to perform thermal curing. Specifically, to close the gate, the needle 223 is advanced to close the opening 222. During the molding process, the cooling device is operated to cool the entire flow path of the thermosetting composition, that is, the filling device 10 of the molding machine and the cooling section 22B provided in the stationary mold 22 of the mold 20. At this time, it is preferable to maintain the entire flow path at 10°C or higher and 50°C or lower, and particularly preferably set it at 30°C or lower.

[0064] Hereinafter, the pressure holding with the plunger 11 and the timing of starting the pressure holding will be described. FIG. 6 is a diagram showing an example of the relationship between the viscosity and time of a thermosetting composition (particularly the thermosetting composition α). In FIG. 6, the period P1 from when the material is injected into the cavity until the filling is completed corresponds to the induction period until heat is applied to the material and curing starts. The curing process is divided into two stages: the initial curing stage P2 from when the material starts to harden after heat is applied until it reaches full cure, and the late curing stage P3 when the curing is completed. The viscosity of the thermosetting composition remains unchanged at a low viscosity during the induction period P1, shows a significant viscosity change from low viscosity to high viscosity during the initial curing stage P2, and gradually increases in the high viscosity state during the late curing stage P3.

[0065] During the initial curing stage P2, not only does the viscosity of the thermosetting composition change from a liquid to a solid, but also a volume change occurs, resulting in shrinkage. Therefore, in actual molding, if pressure is not applied to the thermosetting composition, the molded product will have poor transferability. To improve the transferability, it is preferable to apply pressure (pressure holding) to the thermosetting composition, bring the thermosetting composition into close contact with the mold 20, and refill the thermosetting composition from the gate portion. Also, to obtain a molded product with high transferability, it is preferable to set the timing of starting the pressure holding (pressure holding start time T) to match the timing of transitioning from the induction period P1 to the initial curing stage P2 of the curing process.

[0066] Here, if the viscosity of the thermosetting composition in the cavity 21 can be detected, the pressure holding start time T can be determined. In the thermosetting composition of the present embodiment, since it thickens at the initial stage of curing P2 and simultaneously begins to shrink, it is preferable to detect the time when shrinkage begins. Thereby, the pressure holding start time T can be appropriately determined.

[0067] In the curing step, by applying pressure under the above-described conditions, sink marks and distortion of the molded product can be prevented, and the transferability can be improved. After completion of pressure holding for a certain period of time, as shown in FIG. 5(C), the needle 223 is advanced to close the opening 222, and the thermosetting composition is completely cured by heating for a certain period of time so that an uncured portion does not occur. Here, the plunger 11 is advanced to fill the cavity 21 of the mold 20 with the thermosetting composition, and the time t1 required for filling is set. When the filling is completed, the plunger 11 stops. Further, when the curing of the thermosetting composition is started, the shrinkage of the thermosetting composition occurs at the same time, so that the plunger 11 that has stopped after completion of the filling step starts to advance again. Let the time t2 required from the completion of the filling step until the plunger 11 starts to advance again due to shrinkage. Further, when the time required to completely cure the thermosetting composition by further heating is t3, t1 + t2 + t3 (the total time required for the filling step and the thermosetting step) is preferably 0.2 minutes to 3 minutes. More preferably, it is 0.2 minutes to 2 minutes. If it is 0.2 minutes or less, there is a risk that the curing will be incomplete, and if it is 3 minutes or more, it is not preferable from the viewpoint of mass productivity.

[0068] The mold release step is shown in FIG. 5(D), for example. By separating the movable mold 23 from the fixed mold 22, the cured product in the cavity can be taken out. When the mold release property is poor, an ejector mechanism may be appropriately provided in the mold. The hardness of the cured product is preferably low, and the hardness of type A durometer conforming to JIS K7215 is preferably 20 to 80, more preferably 20 to 70.

[0069] As described above, the resin portion 3 can be formed as a cured product of the thermosetting composition. That is, the resin portion is composed of a cured product of the thermosetting composition.

[0070] In one embodiment, in the step of forming the resin portion 3, a part or all of the lead conductor 2 is inserted into a mold filled with a thermosetting composition. Thereby, the resin portion 3 can be integrally formed with respect to the lead conductor 2, and the adhesion between the lead conductor 2 and the resin portion 3 is further improved. The "part" of the lead conductor 2 may correspond to the region where the resin portion 3 is formed. When all of the lead conductor 2 is inserted into the mold, it is preferable that portions (other portions) other than the "part" that can correspond to the region where the resin portion 3 is formed do not come into contact with the thermosetting composition. The other portions of the lead conductor 2 can be prevented from coming into contact with the thermosetting composition, for example, by masking or by sandwiching (pressing) with the mold. The amount of pressing by the mold can be appropriately adjusted so that resin burrs do not occur in the other portions of the lead conductor 2. Incidentally, resin portions may also be formed in the other portions of the lead conductor 2, and as a post-treatment, the resin portions of the other portions may be removed.

[0071] 2. Tab lead The tab lead according to one aspect of the present invention is a tab lead manufactured by the method for manufacturing a tab lead according to one aspect of the present invention. According to the tab lead of this aspect, the hermeticity in the electrochemical device can be improved.

[0072] The tab lead according to another aspect of the present invention is a tab lead having a lead conductor having a first main surface and a second main surface opposite to the first main surface, and a resin portion covering the first main surface, the second main surface, and both side surfaces between both ends of the lead conductor while exposing both ends of the lead conductor, wherein the resin portion contains a thermosetting resin. The tab lead of this aspect can be manufactured by the method for manufacturing a tab lead according to one aspect of the present invention, and the hermeticity in the electrochemical device can be improved.

[0073] Regarding the tab lead according to one aspect of the present invention and the configuration of the tab lead according to another aspect of the present invention, the description made about the manufacturing method of the tab lead according to one aspect of the present invention is incorporated herein by reference.

[0074] 3. Electrochemical devices (batteries, capacitors) The electrochemical device according to one aspect of the present invention includes the tab lead according to one aspect of the present invention or the tab lead according to another aspect of the present invention. According to the electrochemical device of this aspect, the sealing performance in the electrochemical device can be improved. The electrochemical device can be, for example, a battery, a capacitor, or the like. Examples of the battery include a lithium-ion battery (LiB) and the like. Examples of the capacitor include an electric double layer capacitor (EDLC), a lithium-ion capacitor (LIC), and the like.

[0075] As the form of the electrochemical device, a laminate type (also referred to as a "pouch type") in which an electrode and an electrolytic solution or a solid electrolyte are enclosed inside a bag-shaped laminate material (also referred to as a "packaging material") is preferable. The electrochemical device can be used, for example, as an in-vehicle battery, a storage battery, or the like. In the electrochemical device, the tab lead functions, for example, as a terminal member for extracting electric power. One end of the lead conductor of the tab lead is connected to an electrode disposed inside the packaging material, and the other end is exposed outside the packaging material. An external device connection terminal (for example, a bus bar or the like) can be connected to this other end. The resin portion of the tab lead is disposed so as to seal the gap between the packaging material and the lead conductor.

[0076] With reference to FIG. 7, the schematic configuration of the electrochemical device according to an embodiment will be described. The electrochemical device has a packaging material 6 made of a bag-shaped laminate material, each part enclosed inside the packaging material 6, and tab leads 1, 1 with a part protruding from the packaging material 6.

[0077] The packaging material 6 is in the form of a bag with its upper end formed as a sealing portion 6a. The sheet constituting the packaging material 6 has, for example, a three-layer structure in which an outer layer, a metal layer, and an inner layer are laminated in this order. As the outer layer, for example, polyethylene terephthalate is used. As the inner layer, for example, polypropylene or polyethylene is used. As the metal layer, for example, aluminum or stainless steel is used.

[0078] Inside the packaging material 6, an electrolytic solution 7 is enclosed, and a positive electrode 8, a negative electrode 9, and a separator (not shown) are arranged. The positive electrode 8 and the negative electrode 9 are immersed in the electrolytic solution 7, and the space where the positive electrode 8 is arranged and the space where the negative electrode 9 is arranged are partitioned by the separator. As the positive electrode 8, for example, aluminum is used. As the negative electrode 9, for example, nickel, copper, or an alloy thereof is used. Note that a solid electrolyte may be used instead of the electrolytic solution 7.

[0079] Of the two tab leads 1, 1, one tab lead 1 connected to the positive electrode 8 functions as the positive electrode in the electrochemical device, and the other tab lead 1 connected to the negative electrode 9 functions as the negative electrode in the electrochemical device.

[0080] A part of the outer peripheral surface of the tab lead 1 is in close contact with the sealing portion 6a, and the upper end side portion protrudes upward from the packaging material 6. The lower end portion of the lead conductor 2 is provided as an electrode connection portion and is connected to the positive electrode 8 or the negative electrode 9, for example, by welding or the like. The upper end portion of the lead conductor 2 is provided as a terminal connection portion exposed to the outside from the packaging material 6 and is connected to a connection terminal (not shown) of an external device, for example, by welding or the like. The resin portion 3 covers so as to be in close contact with the first main surface, the second main surface, and both side surfaces between both end portions of the lead conductor 2. Further, the resin portion 3 is also in close contact with the inner surface of the sealing portion 6a of the packaging material 6. Thereby, the packaging material 6 is sealed, and liquid leakage of the electrolytic solution 7 or the like enclosed inside the packaging material 6 can be prevented. Further, by intervening between the lead conductor 2 and the packaging material 6, the resin portion 3 can also ensure the insulation between the lead conductor 2 and the packaging material 6.

Explanation of Reference Numerals

[0081] 1: Tab lead 2: Lead conductor 3: Resin part 4, 5: Thermoplastic resin film 6: Packaging material 7: Electrolyte 8, 9: Electrodes (positive electrode, negative electrode)

Claims

1. A method for manufacturing a tab lead having a lead conductor provided with a first main surface and a second main surface opposite to the first main surface, and a resin portion covering the first main surface, the second main surface, and both side surfaces between both end portions of the lead conductor while exposing both end portions of the lead conductor, comprising: A method, wherein the step of forming the resin portion includes filling a thermosetting composition into a mold.

2. The method according to claim 1, wherein the thermosetting composition contains (A) a di(meth)acrylate compound having a structural unit represented by the following formula (A1), or a compound represented by the following formula (A2) or (A3), and (B) a thermal polymerization initiator. 【Chemical 13】 (In formula (A1), V １０１ is a divalent aromatic hydrocarbon group having 6 to 12 ring-forming carbon atoms which may be substituted or unsubstituted, a divalent alicyclic hydrocarbon group having 5 to 12 ring-forming carbon atoms which may be substituted or unsubstituted, or a divalent aliphatic hydrocarbon group having 2 to 30 carbon atoms which may be substituted or unsubstituted. p represents the average number of constitutional units. When p is 2 or more, two or more Vs １０１ may be the same as each other or different from each other. ) 【Chemical Formula 14】 (In formula (A2), R １１１ and R １１５ is each independently a hydrogen atom or a methyl group. R １１２ is an alkylene group having 1 to 20 carbon atoms. R １１３ and R １１４ are each independently an alkylene group having 1 to 30 carbon atoms. n １１２ represents an integer of 0 or 1. n １１３ represents an integer from 0 to 30.) 【Chemical Formula 15】 (In formula (A3), R １２１ is an alkylene group having 1 to 6 carbon atoms. R １２２ is a hydrogen atom or a methyl group. n １２０ is 3 or 4. n １２１ represents an integer from 0 to 15. n １２０ When n is 3, Z １２０ is a substituted or unsubstituted trivalent aliphatic hydrocarbon group having 3 to 10 carbon atoms. n １２０ When n is 4, Z １２０ is a substituted or unsubstituted tetravalent aliphatic hydrocarbon group having 5 to 10 carbon atoms.)

3. The method according to claim 1 or 2, wherein in the step of forming the resin portion, part or all of the lead conductor is inserted into the mold into which the thermosetting composition is filled.

4. A tab lead manufactured by the method according to any one of claims 1 to 3.

5. A tab lead having a lead conductor provided with a first main surface and a second main surface opposite to the first main surface, and a resin portion covering the first main surface, the second main surface, and both side surfaces between both end portions of the lead conductor while exposing both end portions of the lead conductor, comprising: A tab lead, wherein the resin portion contains a thermosetting resin.

6. The tab lead according to claim 5, wherein the resin portion is composed of a cured product of a thermosetting composition, the thermosetting composition contains (A) a di(meth)acrylate compound having a structural unit represented by the following formula (A1), or a compound represented by the following formula (A2) or (A3), and (B) a thermal polymerization initiator. 【Chemical 16】 (In formula (A1), V １０１ is a divalent aromatic hydrocarbon group having 6 to 12 ring-forming carbon atoms which may be substituted or unsubstituted, a divalent alicyclic hydrocarbon group having 5 to 12 ring-forming carbon atoms which may be substituted or unsubstituted, or a divalent aliphatic hydrocarbon group having 2 to 30 carbon atoms which may be substituted or unsubstituted. p represents the average number of constitutional units. When p is 2 or more, two or more Vs １０１ may be the same as each other or different from each other. ) 【Chemical 17】 (In formula (A2), R １１１ and R １１５ is each independently a hydrogen atom or a methyl group. R １１２ is an alkylene group having 1 to 20 carbon atoms. R １１３ and R １１４ are each independently an alkylene group having 1 to 30 carbon atoms. n １１２ represents an integer of 0 or 1. n １１３ represents an integer from 0 to 30.) 【Chemical Formula 18】 (In formula (A3), R １２１ is an alkylene group having 1 to 6 carbon atoms. R １２２ is a hydrogen atom or a methyl group. n １２０ is 3 or 4. n １２１ represents an integer from 0 to 15. n １２０ When n is 3, Z １２０ is a substituted or unsubstituted trivalent aliphatic hydrocarbon group having 3 to 10 carbon atoms. n １２０ When n is 4, Z １２０ is a substituted or unsubstituted tetravalent aliphatic hydrocarbon group having 5 to 10 carbon atoms.)

7. The tab lead according to any one of claims 4 to 6, wherein the composition of the resin portion is uniform throughout the resin portion.

8. An electrochemical device comprising the tab lead according to any one of claims 4 to 7.

9. A battery comprising the tab lead according to any one of claims 4 to 7.

10. A capacitor comprising the tab lead according to any one of claims 4 to 7.

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