JP2014199816A - Electrode lead wire member for nonaqueous battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrode lead wire member for a nonaqueous battery that is improved in corrosion resistance so as to prolong a lifetime of a lithium ion battery by avoiding adverse influence of increase in corrosiveness even when the corrosiveness increases as an electrolyte of the lithium ion battery reacts with water to produce hydrofluoric acid.SOLUTION: An electrode lead wire member 18 is led out from a storage container for a nonaqueous battery which uses a laminate film stack of an aluminum foil and a resin film as a jacket material. The electrode lead wire member comprises a metallic lead-out part 21, and a sealant layer 23 is laminated on a surface of the lead-out part 21 via an anticorrosive thin-film coating layer 22 made of resin having a skeleton of polyvinyl alcohol containing a hydroxyl group or copolymer resin thereof. The thin film coating layer 22 is cross-linked or amorphized by heat treatment to have resistance to water.

Description

  The present invention relates to an electrode lead member for a non-aqueous battery using an organic electrolyte in an electrolyte such as a lithium ion battery or an electric double layer capacitor (hereinafter referred to as a capacitor) as a secondary battery.

In recent years, with the growing global environmental problems, the diffusion of electric vehicles and the effective use of natural energy such as wind power generation and solar power generation have become issues. Accordingly, in these technical fields, secondary batteries such as lithium ion batteries and capacitors have attracted attention as storage batteries for storing electrical energy. In addition, the outer container for storing lithium-ion batteries used in electric vehicles and the like is made of a flat bag made by using a battery outer laminate in which an aluminum foil and a resin film are laminated, or drawn or stretched. A molded container is used to reduce the thickness and weight.
By the way, the electrolyte solution of a lithium ion battery has the property of being sensitive to moisture and light. For this reason, a battery exterior laminate in which a base material layer made of polyamide or polyester and an aluminum foil are laminated is used as an exterior material for a lithium ion battery, which is excellent in waterproofness and light shielding properties.

  In order to store a lithium ion battery in a storage container created using such a battery outer laminate, for example, as shown in FIG. A tray-like shape having 31 is formed by drawing or the like, and accessories such as a lithium ion battery (not shown) and electrodes are accommodated in the recess 31 of the tray. Next, as shown in FIG. 3B, the lid 33 made of a battery exterior laminate is stacked from above to wrap the battery, and the flange portion 32 of the tray and the four side edges 34 of the lid 33 are heat sealed. And seal the battery. In the storage container 35 formed by the method of placing the battery in the concave portion 31 of the tray, the battery can be stored from above, so that the productivity is high.

In the mounting container 30 of the lithium ion battery shown in FIG. 3A described above, the depth of the tray (hereinafter, the tray depth is sometimes referred to as “throttle”) is conventionally used in a small lithium ion battery. Was about 5 to 6 mm. However, in recent years, storage containers for large batteries have been demanded more than ever for applications such as for electric vehicles. In order to manufacture a storage container for a large battery, a deeper drawing tray has to be formed, which increases technical difficulties.
In addition, when moisture penetrates into the lithium ion battery, the electrolytic solution is decomposed by moisture and strong acid is generated. In this case, the strong acid generated from the inside of the battery exterior laminate penetrates, and as a result, the aluminum foil corrodes and deteriorates with the strong acid, the electrolyte leaks, and the battery performance only deteriorates. In addition, there is a problem that the lithium ion battery may ignite.

JP 2000-357494 A

  As a measure for preventing the surface layer of the aluminum foil or electrode lead wire member constituting the laminate for battery exterior from being corroded by strong acid, Patent Document 1 discloses that the surface of the aluminum foil is subjected to chromate treatment. Although measures have been disclosed to improve the corrosion resistance by forming a chromized coating, the chromate treatment is a problem in terms of environmental measures because it uses heavy metal chromium, and hexavalent chromium has an effect on the human body. Because it is a harmful substance, it cannot be used, and a chromate treatment solution of trivalent chromium is used. Moreover, there exists a problem that the effect of improving corrosion resistance is thin in chemical conversion treatments other than chromate treatment.

  In addition, among conventional electrode lead wire members, of both positive and negative electrodes, the aluminum material that is the positive electrode member has good electrolyte resistance, but the copper plate that is the negative electrode member is nickel-plated on the surface layer. Even if trivalent chromium is chromated, it is inferior in electrolytic solution resistance.

  The present invention has been made in view of the above circumstances, and even if the electrolytic solution of a lithium ion battery reacts with moisture to generate hydrofluoric acid and increase its corrosiveness, the adverse effect is avoided and the lithium ion battery is avoided. An object of the present invention is to provide an electrode lead wire member for a non-aqueous battery with improved corrosion resistance so that the life of the battery is extended.

  The present invention relates to a container for a non-aqueous battery that uses an organic electrolyte as an electrolytic solution, and prints on the outer surface of the electrode lead wire member at the portion where the laminate film laminate of the exterior material and the electrode lead wire member are joined. The technical idea is to improve the corrosion resistance against a corrosive electrolytic solution by laminating a thin film coating layer in a pattern. The thin film coating layer is made of a resin having a polyvinyl alcohol skeleton containing a hydroxyl group or a copolymer resin thereof.

  In order to solve the above problems, the present invention is an electrode lead wire member drawn from a non-aqueous battery storage container using a laminate film laminate of an aluminum foil and a resin film as an exterior material, which is made of metal. A lead portion, and a sealant layer is laminated on the surface of the lead portion via a corrosion-resistant thin film coating layer made of a resin having a skeleton of polyvinyl alcohol containing a hydroxyl group or a copolymer resin thereof; The electrode lead wire member is characterized in that the thin film coating layer is water-resistant by crosslinking or amorphization by heat treatment.

  Further, the thin film coating layer preferably contains a substance that is made of a metal fluoride or a derivative thereof and that crosslinks the thin film coating layer made of a resin having a skeleton of polyvinyl alcohol containing a hydroxyl group or a copolymer resin thereof.

Moreover, it is preferable that the said metal fluoride or its derivative (s) is a substance containing the F < ^- > ion which forms the passive aluminum fluoride.

  In addition, the thin film coating layer is printed on the surface of the lead-out portion to form a strip-like pattern having a width wider than that of the sealant layer along the direction in which the sealant layer is stacked so as to intersect the longitudinal direction of the lead-out portion. It is preferable to be formed. As a result, by joining the current collector inside the non-aqueous battery and the electrode lead wire member, or by not attaching the thin film coating layer to the part where the non-aqueous battery is joined in series or in parallel, joining by ultrasonic or resistance welding, etc. There is an advantage that the bonding property is improved because there is no thin film coating layer in the bonding portion.

  The sealant layer is preferably a maleic anhydride-modified polyolefin resin film or a polyolefin resin film modified with an epoxy functional group.

  Further, the thickness of the sealant layer is 50 μm or more and 300 μm or less, and the thickness of the thin film coating layer is 0.1 to 5.0 μm, and the lead-out part on which the thin film coating layer is formed and the thin film coating layer The delamination strength with the sealant layer laminated on is measured by the peeling measurement method A defined in JIS C6471, and is preferably 40 N / inch or more.

  Moreover, it is preferable that the both end parts seen in the cross section along the junction part with the said exterior material of the said electrode lead wire member are crushed, and thickness is made thinner than the cross-sectional center part.

A thin film coating layer made of a resin having a skeleton of polyvinyl alcohol containing a hydroxyl group or a copolymer resin of the electrode lead wire member is water-resistant by crosslinking or amorphizing by heat treatment, and the electrode lead wire member has It is possible to suppress leakage of the electrolyte solution from both ends viewed in the cross section and infiltration of moisture in the atmosphere into the inside.
If both ends of the electrode lead wire member seen in the cross section are crushed and the thickness is made thinner than the central portion of the cross section, the adhesion between the electrode lead wire member and the laminate film laminate is improved, and there are few voids. Thus, leakage of the electrolyte solution to the outside and infiltration of moisture in the atmosphere into the inside are reduced.

It is a perspective view which shows an example of the storage container for batteries. It is a schematic sectional drawing which shows an example of the exterior laminated body for batteries used for the storage container for batteries. It is a perspective view which shows the process of accommodating a lithium ion battery in a storage container in order. (A) is a perspective view which shows an example of the electrode lead wire member concerning this invention, (b) is sectional drawing which follows the SS line | wire of (a). It is a top view which shows an example of the electrode lead wire member concerning this invention. It is a measurement result which measured the thin film coating layer with the differential thermal analyzer.

The electrode lead wire member according to the present invention will be described with reference to FIGS. 1 and 2, taking as an example a case where the electrode lead wire member is pulled out from a storage container for a lithium ion battery manufactured using a battery exterior laminate.
As shown in FIG. 1, the electrode lead wire member 18 and the lithium ion battery 17 of the present invention are contained in a battery outer container 20 formed by folding a battery outer laminate 10.
Further, the three side edge portions 19 of the battery outer container 20 are heat-sealed and formed into a bag shape. The electrode lead wire member 18 is pulled out from the battery outer container 20 as shown in FIG. In addition, the storage method in the battery storage container of the lithium ion battery manufactured using the electrode lead wire member 18 concerning this invention was shown in FIG.

As shown in FIG. 2, the battery exterior laminate 10 made of a laminate film laminate has a base material layer 11, an aluminum foil 12, and a resin film 13 bonded to each other through adhesive layers 15 and 16, respectively. ing.
As shown in FIG. 4, the electrode lead member 18 includes a lead-out portion 21 made of aluminum or a nickel-plated copper plate, and a sealant layer 23 is a skeleton of polyvinyl alcohol containing a hydroxyl group on the surface of the lead-out portion 21. Are laminated via a corrosion-resistant thin-film coating layer 22 made of a resin having a copolymer or a copolymer resin thereof.
The thin film coating layer 22 is made of a metal fluoride or a derivative thereof, a substance that crosslinks a thin film coating layer made of a resin having a skeleton of polyvinyl alcohol containing a hydroxyl group or a copolymer resin thereof and activating the metal surface. Is contained. However, the corrosion resistance of the thin film coating layer is improved even if the metal fluoride or its derivative is not included.
The thin film coating layer 22 is formed in a pattern on the surface of the lead-out portion 21 by printing.
The thin film coating layer 22 formed on the surface of the lead-out portion 21 is water-resistant by being crosslinked or amorphized by heat treatment.
In addition, the metal surface is activated by using a thin film coating layer containing a substance that is liberated and acidic in the state of an aqueous solution, such as metal fluoride, so that the film on the metal surface and the thin film coating layer is activated. And are strongly bonded.
By the way, it is known that a thin film coating layer made of a resin having a polyvinyl alcohol skeleton or a copolymer resin thereof generally has good gas barrier properties. The inside of the resin that constitutes the thin film coating layer has few voids, and especially in low humidity atmospheres, it has gas barrier properties against gas molecules with a small molecular diameter such as hydrogen gas. In a battery using a non-aqueous electrolyte solution, when a thin film coating layer is used for a component inside the battery that does not contain moisture, it is considered that the barrier property against the electrolyte solution and moisture is high. Therefore, it is expected to have an effect of preventing corrosion because it has a high barrier property against substances that corrode metal surfaces such as hydrofluoric acid. Thus, the corrosion resistance can be improved by cross-linking the thin film coating layer made of a resin having a skeleton of polyvinyl alcohol or a copolymer resin thereof selected from substances containing a hydroxyl group.

The lead-out portion 21 of the electrode lead wire member 18 is generally made of an aluminum plate for the positive electrode and a metal obtained by coating the copper plate with nickel plating for the negative electrode. In order to facilitate thermal joining with the battery exterior laminate 10 made of an aluminum laminate film, a sealant layer 23 is formed and placed in advance on the joining portion of the electrode lead wire member 18. The sealant layer 23 is preferably laminated on both sides so as to sandwich the lead-out portion 21 from both the front and back sides.
If the corrosion-resistant thin film coating layer 22 is not formed on the surface layer of the lead-out part 21, moisture and the electrolyte solution react with each other on the surface layer of the lead-out part 21 due to permeation of the electrolytic solution, and hydrofluoric acid is generated. The corrosion of the part 21 is supposed to deteriorate the adhesion. Therefore, it is preferable that a thin film coating layer 22 made of a resin having a skeleton of polyvinyl alcohol containing a hydroxyl group or a copolymer resin thereof is laminated on at least the surface of the lead-out portion 21 on the battery side. As shown in FIG. 4B, the thin film coating layer 22 needs to be laminated on the entire outer peripheral portion of the cross section of the lead-out portion 21 at the joint portion with the exterior material.
Chromate treatment is widely used as an anti-corrosion measure for the electrolytic solution of the lead-out portion 21 made of aluminum used in the electrode lead wire member according to the prior art, but compared with the lead-out portion 21 made of aluminum, copper is used. The effect of chromate treatment is small for the lead-out portion 21 on which nickel plating is applied. However, it has been found that the electrode lead wire member 18 according to the present invention has an effect of preventing corrosion of the electrolytic solution even in the lead-out portion 21 in which nickel is plated on copper.
From this, it is considered that the corrosion prevention mechanism for the electrolytic solution by the thin film coating layer 22 of the present invention is different from the conventional chromate treatment in the corrosion prevention mechanism.
As shown in FIG. 5, the sealant layer 23 may be laminated so as to straddle both the positive electrode and the negative electrode. Thereby, the electrode lead wire member in which the positive electrode and the negative electrode are integrated can be obtained. Moreover, since the corrosion prevention effect of the thin film coating layer 22 is obtained with respect to various metal plates such as an aluminum plate and a nickel plated copper plate, it is preferable to provide the thin film coating layer 22 in both the positive electrode and negative electrode lead-out portions 21.

A resin having a skeleton of polyvinyl alcohol containing a hydroxyl group or a copolymer resin thereof is a resin obtained by saponifying a polymer of a vinyl ester monomer or a copolymer thereof. Examples of the vinyl ester monomers include fatty acid vinyl esters such as vinyl formate, vinyl acetate, and vinyl butyrate, and aromatic vinyl esters such as vinyl benzoate. Examples of other monomers to be copolymerized include ethylene, propylene, α-olefins, unsaturated acids such as acrylic acid, methacrylic acid, and maleic anhydride, and vinyl halides such as vinyl chloride and vinylidene chloride. As a commercial item, Nippon Synthetic Chemical Co., Ltd. G polymer resin (brand name) is mentioned.
The thin film coating layer 22 preferably contains a substance that crosslinks the thin film coating layer made of a metal fluoride or a derivative thereof and having a polyvinyl alcohol skeleton containing a hydroxyl group or a copolymer resin thereof. Examples of the metal fluoride or derivatives thereof include chromium fluoride, iron fluoride, zirconium fluoride, titanium fluoride, hafnium fluoride, zircon hydrofluoric acid and salts thereof, titanium hydrofluoric acid and salts thereof, and the like. Fluoride is mentioned. These metal fluorides or derivatives thereof are substances that crosslink a resin having a skeleton of polyvinyl alcohol containing a hydroxyl group or a copolymer resin thereof, and at the same time, F ⁻ ions that form a passive aluminum fluoride. Since it is also a substance to be contained, when the lead-out portion 21 is made of aluminum, it is considered that the surface of the lead-out portion 21 can be passivated to enhance the effect of preventing corrosion.

In order to form the thin film coating layer 22 on the surface of the lead-out portion 21, for example, an amorphous polymer having a skeleton of polyvinyl alcohol containing a hydroxyl group (manufactured by Nippon Synthetic Chemical Co., Ltd., trade name: G polymer resin) Is applied so that the thickness after drying is about 0.1 to 5 μm using an aqueous solution in which 0.2 to 6 wt% and 0.1 to 3 wt% of chromium (III) fluoride are dissolved. The thin film coating layer 22 can be formed by performing heat drying, baking adhesion, and crosslinking.
FIG. 6 shows an aqueous solution in which 3 wt% of an amorphous polymer containing a hydroxyl group-containing polyvinyl alcohol skeleton (manufactured by Nippon Synthetic Chemical Co., Ltd., trade name: G polymer resin) and 1 wt% of chromium (III) fluoride are dissolved. An example of the result of measuring with a differential thermal analyzer a thin film coating layer that has been applied so as to have a thickness of 3 μm after being dried using a film and further heat-dried in an oven at 200 ° C. is shown. As a result of confirmation of the melting point, it was found that there was no peak in the melting point, so that crosslinking occurred.

In this way, when the thin film coating layer 22 is laminated on the surface layer surface of the lead-out part 21, the pressure resistance of the thin film coating layer 22 is high, so that even if the thickness of the polypropylene layer or polyethylene layer as the sealant layer 23 is reduced. Since the pressure strength can be maintained, the penetration of moisture from the edge portion (side edge portion) of the lead-out portion 21 into the lithium ion battery is reduced, and the deterioration with time of the electrolyte solution of the lithium ion battery is reduced. become longer.
Furthermore, even when a small amount of water enters the battery and hydrofluoric acid is generated by the reaction between the electrolytic solution and the water and decomposition of the electrolytic solution, it contains a hydroxyl group laminated on the surface of the lead-out portion 21. The thin film coating layer 22 made of a resin having a polyvinyl alcohol skeleton or a copolymer resin thereof has a low free volume, so has a high gas barrier property, diffuses to the outside along the sealant layer, and a small amount of hydrofluoric acid is generated. Even when the lead plate 21 is in contact with the surface of the aluminum plate, the passivation film formed on the surface of the aluminum plate prevents the lead portion 21 from being corroded, and the interlayer adhesion between the lead portion 21 and the sealant layer 23 is prevented. Strength is maintained, pressure holding strength is increased, and problems such as battery leakage do not occur.

The thickness of the sealant layer 23 to be bonded in advance is preferably 50 to 300 μm, and 50 to 150 μm is the best considering waterproofness. If the thickness of the lead-out portion 21 is 200 μm or more, a through hole may be formed at the edge of the lead-out portion 21 and the electrolyte solution may not be sealed. Therefore, as shown in FIG. 4B, both end portions 24 of the lead-out portion 21 seen in a cross section along the joint portion with the exterior material are crushed so that the thickness is thinner than the central portion of the cross section. preferable. Thereby, the thickness of the sealant layer 23 to be bonded in advance can be reduced.
The thickness of the thin film coating layer 22 made of a resin having a polyvinyl alcohol skeleton containing a hydroxyl group or a copolymer resin thereof is preferably 0.1 to 5.0 μm, more preferably 0.5 to 3 μm. When the thickness of the thin film coating layer, the performance of moisture resistance and adhesive strength increases.

The thin film coating layer 22 is applied to a necessary portion of the lead-out portion 21 by a printing method. As the printing method, a known printing method such as an inkjet method, a dispenser method, or a spray coating method can be used. The printing method that can be used in the present invention is arbitrary. However, since it is necessary to print not only the surface layer of the lead-out portion 21 but also the edge portion viewed in the cross section of the electrode lead wire member, the inkjet method and the dispenser method are preferable. In particular, in the dispenser method, when an experiment was performed using a coating head capable of printing with a width as thin as about 10 mm, it was found that this was the most suitable method.
The sealant layer 23 to be bonded to the electrode lead wire member in advance is preferably a resin film that is the same as or similar to the resin film 13 used for the innermost layer of the aluminum laminate film 10, and the resin film 13 is generally used. In the case of polypropylene, the sealant layer 23 is an unstretched polypropylene (CPP), a maleic anhydride-modified propylene single film, or a single film of polypropylene modified with a monomer having an epoxy functional group such as glycidyl methacrylate. A multilayer film of this and polypropylene may be used. Even when the resin film 13 is polyethylene, the sealant layer 23 may be polyethylene, maleic anhydride-modified polyethylene, or a single polyethylene modified with a monomer having an epoxy functional group such as glycidyl methacrylate. And a multilayer film with the copolymer thereof. In this case, the surface in contact with the electrolytic solution may be maleic anhydride, a copolymer of acrylic acid, polyethylene modified with glycidyl methacrylate, or the like.

  Examples of the non-aqueous battery in which the present invention is used include those using an organic electrolyte in an electrolytic solution such as a lithium ion battery or an electric double layer capacitor which is a secondary battery. As the organic electrolyte, those using carbonate esters such as propylene carbonate (PC), diethyl carbonate (DEC), and ethylene carbonate as a medium are common, but not particularly limited thereto.

(Measuring method)
・ Measurement method of adhesion strength between lead-out part of electrode lead wire member and sealant layer: JIS C6471 “Copper-clad laminate test for flexible printed wiring board using a measurement sample in which an aluminum laminate film is heat-sealed on the sealant layer The measurement was performed by the measurement method defined in “Method”.
Measurement method of electrolyte strength retention: Using a laminate for battery exterior, a 50 × 50 mm (heat seal width is 5 mm) four-sided bag was formed, and 1 mol / liter of LiPF ₆ was added therein. 0.5 wt% of pure water was added to the PC / DEC electrolyte, and 2 cc of it was weighed, filled and packaged. In this four-sided bag, a thin film coating layer is printed by a dispenser method on a part of the surface of the lead portion of the electrode lead wire member, and a sealant layer is laminated on the thin film coating layer by heat sealing. After putting the member and storing it in an oven at 60 ° C. for 100 hours, the interlayer adhesion strength (k2) between the thin film coating layer and the sealant layer of the electrode lead wire member is measured.
Here, the interlayer adhesion strength (k1) between the thin film coating layer before being exposed to the electrolytic solution and the polypropylene (PP) film as the sealant layer, and the interlayer adhesion after being exposed to the electrolytic solution, which were measured in advance. The ratio with the strength (k2) was defined as the electrolyte strength retention ratio K = (k2 / k1) × 100 (%).
(measuring device)
・ Adhesive strength measuring device: manufactured by Shimadzu Corporation, model: AUTOGRAPH AGS-100A tensile testing device

Example 1
As a lead-out portion of the electrode lead wire member for a lithium battery, an aluminum piece obtained by cutting an aluminum plate having a thickness of 200 μm into a size of 50 mm × 60 mm was used. 3 wt% of an amorphous polymer having a polyvinyl alcohol skeleton containing hydroxyl groups (trade name: G polymer resin, manufactured by Nippon Synthetic Chemical Co., Ltd.) and chromium fluoride (III) 1 μm thick aqueous solution was used to coat both sides with a 10 μm-wide dispenser with a thickness of 1 μm, a thin film coating layer was laminated, and further dried by heating in an oven at 200 ° C., simultaneously with baking the resin of the thin film coating layer Cross-linked. At this time, it was confirmed that the thin film coating layer was applied not only to the front and back surface layers of the lead-out part but also to both end faces of the lead-out part.
Furthermore, a single layer film of a maleic anhydride-modified polypropylene film (polypropylene resin made by Mitsui Chemicals, product name / Admer QE060 is used to form a film with a film thickness of 100 μm is used on the thin coating layer on the surface of the lead-out portion. The electrode lead wire member of Example 1 was obtained.
An aluminum laminate film having a thickness of 120 μm composed of an aluminum foil (thickness: 20 μm) / maleic anhydride-modified polypropylene film (thickness: 100 μm) was heat-sealed on the sealant layer of the electrode lead wire member of Example 1. Example 1 A measurement sample using the electrode lead wire member was prepared.
A test piece for measuring the adhesive strength was collected from the measurement sample of Example 1, and the adhesive strength between the lead-out portion and the sealant layer was measured. The result showed an adhesive strength of 46 N / inch.
Moreover, the measurement result of the electrolyte solution strength retention rate K for the measurement sample of Example 1 was K = 88%.

(Example 2)
As a lead-out part of an electrode lead wire member for a lithium battery, nickel sulfamic acid plating is plated with a thickness of 2 to 5 μm on the surface of a copper plate piece (dimension 50 mm × 60 mm) having a thickness of 200 μm, and a hydroxyl group is partly contained 1 μm in thickness using an aqueous solution in which 3 wt% of an amorphous polymer having a polyvinyl alcohol skeleton (product name: G polymer resin) manufactured by Nippon Synthetic Chemical Co., Ltd. and 1 wt% of chromium (III) fluoride is dissolved The thin film coating layer was applied, laminated, and dried by heating in an oven at 200 ° C., and the resin of the thin film coating layer was baked and simultaneously crosslinked.
Furthermore, on the thin film coating layer on the surface of the lead-out portion, a maleic anhydride-modified polypropylene film single layer (Mitsui Chemicals polypropylene-based resin, product name: Admer QE060 is used to form a film with a film thickness of 100 μm) is used. The electrode lead wire member of Example 2 was obtained by performing double-sided thermal bonding by heat sealing.
Using the electrode lead wire member of Example 2, the aluminum laminate film was heat sealed in the same manner as in Example 1 to obtain a measurement sample of Example 2, and the adhesive strength between the lead-out portion and the sealant layer was measured. An adhesion strength of 44 N / inch was shown.
Moreover, the result of having measured the electrolyte solution strength retention K about a part of the battery storage container of Example 2 was K = 78%.

(Comparative Example 1)
The electrode lead wire member and the measurement sample of Comparative Example 1 were obtained in the same manner as in Example 1 except that the thin film coating layer was not laminated on the aluminum plate, and the adhesion strength between the lead-out portion and the sealant layer was measured. Inch adhesive strength was shown. Moreover, the result of having measured the electrolyte solution strength retention K about the measurement sample of the comparative example 1 was K = 10% or less.

(Comparative Example 2)
As a lead-out part of an electrode lead wire member for a lithium battery, a surface of a copper plate piece (dimensions 50 mm × 60 mm) having a thickness of 200 μm is subjected to nickel sulfamate plating of about 2 to 5 μm, and a part thereof includes a hydroxyl group-containing polyvinyl It is applied at a thickness of 1 μm using a paint that is a mixture of 3 wt% of an amorphous polymer with alcohol skeleton (manufactured by Nippon Synthetic Chemical Co., Ltd., trade name: G polymer resin) and 1 wt% of chromium (III) fluoride. A thin film coating layer was laminated. An electrode lead wire member and a measurement sample of Comparative Example 2 were obtained in the same manner as in Example 1 except that the heat drying treatment was not performed after the lamination.
With respect to the electrode lead wire member and measurement sample of Comparative Example 2, when the adhesion strength between the lead-out portion and the sealant layer was measured, an adhesion strength of 46 N / inch was shown. Moreover, the measurement result of the electrolyte solution strength retention rate K for the measurement sample of Comparative Example 2 was K = 10% or less. After the measurement of the electrolytic solution strength retention rate, the lead-out portion of the electrode lead wire member and the sealant layer caused a peeling phenomenon (delamination) due to exposure to the electrolytic solution.

  The above results are summarized in Table 1. In Table 1, “adhesive strength between the lead portion of the electrode lead wire member and the sealant layer” is simply “adhesive strength”.

In Example 1 and Example 2, 3 wt% of an amorphous polymer having a polyvinyl alcohol skeleton containing a hydroxyl group (manufactured by Nippon Synthetic Chemical Co., Ltd., trade name: G polymer resin), and chromium fluoride (III) The coating strength mixed with 1 wt% is applied to the lead portion of the electrode lead wire member, and since the thin film coating layer is laminated, the adhesive strength between the lead portion of the electrode lead wire member and the sealant layer is 40 N / inch or more. It is. In addition, the electrode lead wire member in which the thin film coating layer was applied between the sealant layer and the lead-out portion was resistant to the electrolytic solution of the lithium battery, and the pressure strength was high.
On the other hand, Comparative Example 1 is a case where the thin film coating layer was not laminated on the electrode lead wire member, but the adhesive strength between the lead portion of the electrode lead wire member and the sealant layer is as high as 54 N / inch. The electrolyte solution strength retention ratio K is 10% or less and there is no electrolyte solution resistance.
Comparative Example 2 is a case where the thin film coating layer was applied to the electrode lead wire member but was not heated and dried. The adhesion strength between the lead portion of the electrode lead wire member and the sealant layer was 46 N / Inch, the electrolyte strength retention ratio K is 10% or less, and there is no resistance to electrolyte.

DESCRIPTION OF SYMBOLS 10 ... Laminate for battery exterior, 11 ... Base material layer, 12 ... Aluminum foil, 13 ... Resin film, 15, 16 ... Adhesive layer, 17 ... Lithium ion battery, 18 ... Electrode lead wire member, 19 ... Side edge 20 ... battery outer container, 21 ... lead-out part, 22 ... thin film coating layer, 23 ... sealant layer, 30 ... battery mounting container, 35 ... battery storage container.

Claims (6)

  An electrode lead wire member drawn from a non-aqueous battery storage container using a laminate film laminate of an aluminum foil and a resin film as an exterior material, comprising a metal lead-out portion on the surface of the lead-out portion The sealant layer is laminated via a corrosion-resistant thin film coating layer made of a resin having a polyvinyl alcohol skeleton containing a hydroxyl group or a copolymer resin thereof, and the thin film coating layer is crosslinked or non-coated by heat treatment. An electrode lead wire member characterized by being water-resistant by crystallization.   The thin film coating layer is made of a metal fluoride or a derivative thereof, and contains a substance that crosslinks a thin film coating layer made of a resin having a skeleton of polyvinyl alcohol containing a hydroxyl group or a copolymer resin thereof. 2. The electrode lead wire member according to 1. The electrode lead wire member according to claim 2, wherein the metal fluoride or a derivative thereof is a substance containing F ⁻ ions that form a passive aluminum fluoride.   The thin film coating layer is formed by printing on the surface of the lead-out portion into a strip-like pattern having a width wider than the sealant layer along a direction in which the sealant layer is stacked so as to intersect with the longitudinal direction of the lead-out portion. The electrode lead wire member according to any one of claims 1 to 3, wherein   The electrode lead wire member according to any one of claims 1 to 4, wherein the sealant layer is a maleic anhydride-modified polyolefin resin film or a polyolefin resin film modified with an epoxy functional group. .   The thickness of the sealant layer is not less than 50 μm and not more than 300 μm, and the thickness of the thin film coating layer is 0.1 to 5.0 μm, and the lead portion on which the thin film coating layer is formed and the thin film coating layer The delamination strength with the sealant layer laminated on the substrate is 40 N / inch or more, as measured by a peeling measurement method A defined in JIS C6471. Electrode lead wire member.

Images