KR20130102472A - Electrode lead wire member for nonaqueous battery - Google Patents

Abstract

PURPOSE: An electrode lead wire is provided to obtain excellent water resistance by crosslinking a protection layer by heat-treating a protection layer, thereby preventing electrolyte leakage and penetration of moisture inside a battery. CONSTITUTION: An electrode lead wire (18) is drawn from a nonaqueous battery case which is formed by using the film laminate of an aluminum foil and a resin film as an exterior and has a protection layer (22) on which a solution containing a polyvinylalcohol-based resin or a polyvinylether-based resin and a fluorine compound is spread and dried on the outer circumference of a metal plate. The fluorine compound is water-soluble. The protection layer is formed in a stripe pattern on the outer surface of the metal plate by printing.

Description

ELECTRODE LEAD WIRE MEMBER FOR NONAQUEOUS BATTERY}

TECHNICAL FIELD The present invention relates to an electrode lead wire 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") that is a secondary battery.

In recent years, as environmental problems are increasing worldwide, the use of natural energy, such as the spread of electric vehicles, wind power generation and solar power generation, has become a problem. Accordingly, in these technical fields, attention is paid to secondary batteries such as lithium ion batteries and capacitors as storage batteries for storing electrical energy. Moreover, in the exterior container which accommodates lithium ion batteries used for an electric vehicle etc., the flat bag produced by using the battery exterior laminated body which laminated | stacked aluminum foil and the resin film, drawing molding, or unloading ( Molding containers by molding are used to achieve thin weight and light weight.

However, the electrolyte of a lithium ion battery has the property of being weak to moisture or light. Therefore, the battery exterior laminated body which is excellent in waterproofness and light-shielding property by which the base material layer which consists of polyamide and polyester and aluminum foil laminated | stacked is used for the lithium ion battery exterior material.

In order to accommodate a lithium ion battery in the storage container produced using such a battery exterior laminated body, the mounting container 30 as shown to Fig.3 (a) is used, for example. The tray-shaped mounting container 30 having the recesses 31 is molded in advance by drawing molding or the like using a battery exterior laminate, and a lithium ion battery is formed in the recess 31 of the tray (the mounting container 30). (Not shown) and accessories such as electrodes are housed. Subsequently, as shown in FIG.3 (b), the cover material 33 which consists of a battery exterior laminated body is piled up from the top, and a battery is wrapped, and the flange part 32 of the tray and the four side edge parts 34 of the cover material 33 are covered. Heat seal to seal the battery. In the storage container 35 formed by the method of mounting a battery in the recessed part 31 of this tray, since a battery can be accommodated from the top, productivity is high.

In the mounting container 30 of the lithium ion battery shown in FIG. 3A, the depth of the tray (hereinafter, the depth of the tray may be referred to as "drawing") is 5 in a conventional small lithium ion battery. It was about -6 mm. However, in recent years, large-sized battery storage containers have been demanded for applications such as electric vehicles. In order to manufacture a large battery storage container, it is necessary to shape the tray of a deeper drawing, and technical difficulty increases.

In addition, when moisture invades the inside of the lithium ion battery, the electrolyte reacts with the moisture and the electrolyte is decomposed to generate strong acid (fluoric acid or the like). In this case, there is a possibility that the generated strong acid permeates the battery exterior laminate from the inside thereof, and the aluminum foil is corroded by the strong acid to deteriorate. As a result, liquid leakage of electrolyte solution occurs and battery performance deteriorates, and a lithium ion battery may ignite.

Japanese Unexamined Patent Publication No. 2000-357494

As a countermeasure for preventing the surface layer of the aluminum foil or the electrode lead wire member constituting the battery exterior laminate from being corroded by a strong acid, Japanese Laid-Open Patent Publication No. 2000-357494 has a chromium treatment on the surface of an aluminum foil. The countermeasure which forms a heat treatment film and improves corrosion resistance is disclosed. However, since chromate treatment uses chromium which is a heavy metal, it is not preferable from a viewpoint of environmental measures. Since hexavalent chromium cannot be used because it is a harmful substance affecting the human body, a chromate treatment solution of trivalent chromium is used. In addition, in the chemical conversion treatment other than the chromate treatment, the effect of improving the corrosion resistance is small.

In the conventional electrode lead wire member, the aluminum material, which is the electrode member of the anode, of both the electrodes of the positive electrode and the negative electrode has good electrolyte resistance. The copper plate which is an electrode member of a negative electrode gives nickel plating to a surface layer, and is inferior to electrolyte solution even if it performs the chromate treatment of trivalent chromium further.

This invention is made | formed in view of the said situation. SUMMARY OF THE INVENTION An object of the present invention is to provide an electrode lead wire member for a non-aqueous battery in which corrosion resistance is improved so that even if the electrolyte of a lithium ion battery reacts with water and hydrofluoric acid is generated and corrosiveness is increased, the adverse effect thereof is extended and the life of the lithium ion battery is extended. It is.

The present invention relates to a non-aqueous battery storage container using an organic electrolyte as an electrolyte, in which a laminate film of a packaging material and an electrode lead wire member are joined to an outer surface of a flat metal plate formed by printing. It is a technical idea to form a protective layer in a strip | belt-shaped pattern, and to improve corrosion resistance with respect to a corrosive electrolyte solution. This protective layer is formed by coating and drying a solution containing polyvinyl alcohol resin or polyvinyl ether resin and a fluorine compound.

MEANS TO SOLVE THE PROBLEM In order to solve the said subject, this invention is an electrode lead wire member drawn out from the storage container for non-aqueous batteries which uses the laminated film laminated body of aluminum foil and a resin film as an exterior material, Comprising: An electrode lead wire member having a protective layer formed by applying and drying a solution containing polyvinyl alcohol-based resin or polyvinyl ether-based resin and a fluorine compound is provided.

Moreover, it is preferable that the said fluorine compound is water-soluble.

Moreover, it is preferable that the said protective layer is formed in the strip | belt-shaped pattern by printing on the outer surface of the said metal flat plate.

Moreover, it is preferable that the said protective layer is bridge | crosslinked or amorphized by heat processing, and has water resistance.

The present invention also provides a storage container for a non-aqueous battery in which the electrode lead wire member is used.

Moreover, it is preferable that both ends seen from the cross section along the junction part with the said exterior member of the said electrode lead wire member are pressed, and are thinner than the center part of a cross section.

After apply | coating the solution containing polyvinyl alcohol-type resin or polyvinyl ether-type resin, and a fluorine compound of an electrode lead wire member, the protective layer formed by drying is crosslinked or uncrystallized by heat processing, and becomes water-resistant. As a result, electrolyte leakage from the both ends seen from the cross section of the electrode lead wire member, or moisture in the air is suppressed from entering the interior.

When both ends seen from the cross section of the electrode lead wire member are pressed, and the thickness is thinner than the cross-section central part, adhesion between the electrode lead wire member and the laminate film laminate is improved and the voids are reduced, so that the electrolyte leaks to the outside or the moisture in the air is internal. Invasion is reduced.

1 is a perspective view illustrating an example of a battery storage container.
2 is a schematic cross-sectional view showing an example of a battery exterior laminate used for a battery storage container.
3A is a perspective view illustrating a first step of storing a lithium ion battery in a storage container.
3B is a perspective view illustrating a second step of storing a lithium ion battery in a storage container.
4A is a perspective view showing an example of an electrode lead wire member according to the present invention.
(B) is sectional drawing along the SS line of FIG.
5 is a plan view showing an example of an electrode lead wire member according to the present invention.
6 shows measurement results of a protective layer measured by a differential thermal analysis device.

An electrode lead wire member according to the present invention will be described with reference to FIGS. 1 to 6. Moreover, the electrode lead wire member drawn out from the lithium ion battery storage container manufactured using the battery exterior laminated body is demonstrated as an example.

1, the electrode lead wire member 18 and the lithium ion battery 17 of the present invention are embedded in a battery outer container 20 manufactured by folding and stacking a battery external laminate 10 (see FIG. 2) .

The battery outer container 20 is produced in a bag shape by heat-sealing the three-sided edge portions 19. The electrode lead wire member 18 is drawn out from the battery outer container 20. Moreover, the method of accommodating the lithium ion battery manufactured using the electrode lead wire member 18 which concerns on this invention in the battery storage container is shown to FIG. 3 (a) and FIG. 3 (b).

As shown in FIG. 2, in the battery exterior laminated body 10 which consists of a laminated film laminated body, the base material layer 11, the aluminum foil 12, and the resin film 13 interposed through the adhesive bond layers 15 and 16, respectively. They are glued in order.

As shown in Figs. 4A and 4B, the electrode lead wire member 18 is made of polyvinyl alcohol based on a metal flat plate 21 made of aluminum or copper plate coated with nickel plating. After applying a solution containing a resin or a polyvinyl ether resin (hereinafter sometimes referred to simply as "polyvinyl alcohol resin") and a fluorine compound, a protective layer 22 formed by drying is laminated. . The sealant layer 23 is laminated on the surface of the protective layer 22.

The protective layer 22 is formed by crosslinking a fluorine compound made of a metal fluoride or a derivative thereof and a polyvinyl alcohol-based resin, and can improve water resistance and also activate the surface of the metal flat plate 21 to improve corrosion resistance. . However, even if the metal fluoride or its derivative is not contained, the corrosion resistance of the protective layer 22 is improved.

The protective layer 22 is formed in the strip | belt-shaped pattern by printing on the outer surface of the metal flat plate 21. As shown in FIG. The band-shaped protective layer 22 formed on the outer surface of the metal flat plate 21 is improved in water resistance by being crosslinked or amorphized by heat treatment.

In addition, by incorporating a substance which becomes free and acidic in an aqueous solution state into the protective layer 22, such as a metal fluoride, the metal surface is activated to improve corrosion resistance and the outer surface and the protective layer 22 of the metal flat plate 21. ) Is strongly bonded.

On the other hand, polyvinyl alcohol-based resins having a skeleton of polyvinyl alcohol are generally known to be excellent in gas barrier properties. Since the protective layer 22 of the electrode lead wire member according to the present invention is formed using a polyvinyl alcohol-based resin, the inside of the resin constituting the protective layer 22 has few voids, and especially in an atmosphere with low humidity, Even gas molecules with the same molecular diameter have gas barrier properties. Therefore, in a battery using a non-aqueous electrolytic solution such as a lithium battery or a capacitor, when the protective layer 22 of the present invention is used for a constituent member inside a battery in which water does not exist, the barrier property against the electrolytic solution or moisture is high. I think. Therefore, since the barrier property with respect to the substance which corrodes metal surfaces, such as hydrofluoric acid, is also high, anticorrosive effect is anticipated. In this manner, the protective layer 22 made of polyvinyl alcohol-based resin can be crosslinked to improve the corrosion resistance.

The metal flat plate 21 of the electrode lead wire member 18 generally uses an aluminum plate with a positive electrode coated with a nickel plated copper plate. The sealant layer 23 is formed in advance in the bonding portion of the electrode lead wire member 18 in order to facilitate thermal bonding between the battery exterior laminate 10 made of an aluminum laminate film and the electrode lead wire member 18. As for the sealant layer 23, it is preferable to laminate | stack the metal flat plate 21 on both surfaces as if sandwiching from both sides.

If the corrosion resistant protective layer 22 is not formed on the surface layer of the metal plate 21, moisture and electrolyte react at the surface layer of the metal plate 21 due to penetration of the electrolyte solution into the electrode lead wire member 18. There is a possibility of hydrofluoric acid. The metal flat plate 21 is corroded by the generated hydrofluoric acid, which may deteriorate the adhesion between the metal flat plate 21 and the sealant layer 23. Therefore, it is preferable that the protective layer 22 is formed by apply | coating the solution containing polyvinyl alcohol-type resin and a fluorine compound on the battery side surface layer surface of the metal plate 21 at least. As shown in FIG.4 (b), in the junction part with the exterior material (battery exterior laminated body 10), it is necessary to laminate | stack the protective layer 22 in the whole outer peripheral part of the cross section of the metal flat plate 21. As shown to FIG.

In the prior art, chromate treatment is widely used as a countermeasure against corrosion of the electrolyte solution in the metal flat plate 21 made of aluminum used for the electrode lead wire member. However, compared with the metal flat plate 21 made from aluminum, the effect of chromate treatment is small with respect to the metal flat plate 21 which nickel-plated copper. However, it was found that the electrode lead wire member 18 according to the present invention also has an effect of preventing corrosion against the electrolytic solution even for the metal flat plate 21 on which nickel is plated.

In this regard, the corrosion prevention of the electrolytic solution by the protective layer 22 of the present invention is considered that the mechanism of corrosion prevention is different from the chromate treatment of the prior art.

The sealant layer 23 may be laminated so as to cover both the anode and the cathode, as shown in FIG. 5. Thereby, the electrode lead wire member in which an anode and a cathode were integrated can be obtained. In addition, since the corrosion protection effect of the protective layer 22 is obtained with respect to various metal plates, such as an aluminum plate and the copper plate coat | covered with nickel plating, it is preferable to form the protective layer 22 in the both metal plates 21 of a positive electrode and a negative electrode. Do.

On the other hand, the protective layer 22 of the electrode lead wire member which concerns on this invention is formed by apply | coating and drying the solution containing polyvinyl alcohol-type resin and a fluorine compound. The manufacturing method of polyvinyl alcohol-type resin is not specifically limited, It can manufacture by a well-known method. For example, a polyvinyl alcohol-based resin can be produced by saponifying a polymer of a vinyl ester monomer or a copolymer thereof. In this invention, polyvinyl alcohol-type resin means at least 1 sort (s) of water-soluble resin chosen from polyvinyl alcohol resin and modified polyvinyl alcohol resin. Here, as a polymer of a vinyl ester monomer or its copolymer, homopolymer or copolymer of vinyl ester monomers, such as fatty acid vinyl esters, such as vinyl formate, a vinyl acetate, and a vinyl butyrate, and aromatic vinyl esters, such as vinyl benzoate, and The copolymer of the other monomer copolymerizable with this, etc. are mentioned. As another monomer which can be copolymerized, For example, olefins, such as ethylene and a propylene, ether group containing monomers, such as alkyl vinyl ether, diacetone acrylamide, diacetone (meth) acrylate, aceto acetate allyl, aceto acetate ester, etc. And unsaturated carboxylic acids such as a carbonyl group (ketone group) -containing monomer, acrylic acid, methacrylic acid and maleic anhydride, vinyl halides such as vinyl chloride and vinylidene chloride, and unsaturated sulfonic acids. 90-100 mol% is preferable and, as for the saponification degree of polyvinyl alcohol-type resin, 95 mol% or more is more preferable.

Examples of the polyvinyl alcohol-based resin and derivatives thereof that can be used in the present invention include alkyl ether-modified polyvinyl alcohol resins, carbonyl-modified polyvinyl alcohol resins, acetoacetyl-modified polyvinyl alcohol resins, acetamide-modified polyvinyl alcohol resins, and acrylics. Nitrile modified polyvinyl alcohol resin, carboxyl modified polyvinyl alcohol resin, silicone modified polyvinyl alcohol resin, ethylene modified polyvinyl alcohol resin, etc. are mentioned. Among these, alkyl ether modified polyvinyl alcohol resin, carbonyl modified polyvinyl alcohol resin, carboxyl modified polyvinyl alcohol resin, acetoacetyl modified polyvinyl alcohol resin is preferable.

As a commercial item of the polyvinyl alcohol-type resin which is generally available, G polymer resin (brand name) of Nippon Kosei Chemical Co., Ltd. product, J-Pobaru DF-20 (brand name) of Nippon Sakubi Pobaru Co., Ltd. product Nippon Kabaido Kogyo Co., Ltd. cross-mer H series (brand name) etc. are mentioned. Polyvinyl alcohol-type resin may use 1 type, or 2 or more types of mixtures.

In addition, Nippon Kabaido Kogyo Co., Ltd. cross-mer H series (brand name) is also known as polyvinyl ether resin (vinyl ether polymer), but in the present invention has a hydroxyl group in place of polyvinyl alcohol resin having a hydroxyl group Or a polyvinyl ether resin that does not have to have a hydroxyl group. As polyvinyl ether resin, ethyl vinyl ether, n-propyl vinyl ether, isopropyl vinyl ether, n-butyl vinyl ether, isobutyl vinyl ether, 2-ethylhexyl vinyl ether, cyclohexyl vinyl ether, norbornyl vinyl ether And homopolymers or copolymers of aliphatic vinyl ethers such as allyl vinyl ether, norbornenyl vinyl ether, 2-hydroxyethyl vinyl ether, diethylene glycol mono vinyl ether, and copolymers of other monomers copolymerizable therewith. . As another monomer copolymerizable with a vinyl ether monomer, the same thing as the other monomer copolymerizable with the vinyl ester monomer mentioned above is mentioned.

Polyvinyl ether containing the aliphatic vinyl ether which has hydroxyl groups, such as 2-hydroxyethyl vinyl ether, diethylene glycol monovinyl ether, 2-hydroxypropyl vinyl ether, and other various glycols and the monovinyl ether of polyhydric alcohol, as a monomer. Since the resin has water solubility and crosslinking reaction with respect to hydroxyl group is possible, it can be suitably used in the present invention.

These polyvinyl ether resins can be produced without undergoing saponification, unlike polyvinyl alcohol resins produced via vinyl ester polymers in that vinyl ether monomers can be used in the resin (polymerization) process. Do. In addition, a copolymer comprising a vinyl ester monomer and a vinyl ether monomer, or a vinyl alcohol-vinyl ether copolymer obtained by saponifying it may be used. It is also possible to use a mixture of polyvinyl alcohol resin and polyvinyl ether resin other than polyvinyl ether resin.

Moreover, it is preferable that the protective layer 22 contains the substance which crosslinks polyvinyl alcohol-type resin as a metal fluoride or its derivative (s). Since fluorine compounds, such as a metal fluoride or its derivative (s), need to be mixed with water-soluble polyvinyl alcohol-type resin, what has water solubility is preferable. Specific examples of the metal fluoride or its derivatives include fluorides such as chromium fluoride, iron fluoride, zirconium fluoride, titanium fluoride, hafnium fluoride, zircon hydrofluoric acid and salts thereof, titanium hydrofluoric acid and salts thereof. These metal fluorides or derivatives thereof are a substance which crosslinks a polyvinyl alcohol-based resin and a substance containing F ⁻ ions which form a fluoride of passivated aluminum. As a result, when the metal flat plate 21 is made of aluminum, it is thought that the surface of the metal flat plate 21 is passivated and corrosion resistance improves.

In order to form the protective layer 22 on the surface layer surface of this metal flat plate 21, For example, polyvinyl alcohol-type resin (Nippon Kosei Chemical Co., Ltd. make, brand name: G polymer resin, Nippon Sakubi Pobaru ( Note) Manufacture, brand name: J-Pobaru DF-20, Nippon Kabaido Kogyo Co., Ltd., product name: Crosslinker H series, etc.) 0.2-6 wt% and an aqueous solution obtained by dissolving 0.1-3 wt% of chromium fluoride (III) After apply | coating so that the thickness after drying may be about 0.1-5 micrometers, the protective layer 22 can be formed by heat-drying, baking, and crosslinking in an oven again.

To FIG. 6, it apply | coated so that thickness after drying might be set to 0.6 micrometer using the aqueous solution which melt | dissolved 3 wt% of polyvinyl alcohol-type resin (made by Nippon Kosei Chemical Co., Ltd., brand name: G polymer resin), and 1 wt% of chromium (III) fluoride. Then, an example of the result of having measured the protective layer formed by heat-drying in 200 degreeC oven again with the differential thermal analysis device is shown. As a result of confirming the melting point, it was found that there was no peak of the melting point and thus was crosslinked.

Thus, when the protective layer 22 is laminated | stacked on the surface layer surface of the metal flat plate 21, since the pressure resistance strength of the protective layer 22 is high, the thickness of the polypropylene layer or polyethylene layer which is the sealant layer 23 is made thin. Even if the pressure resistance can be maintained. Therefore, moisture intrusion from the edge part (side edge part) of the metal flat plate 21 into the inside of a lithium ion battery becomes small, and the deterioration of the electrolyte solution of a lithium ion battery with time decreases, and the product lifetime of a battery becomes long.

In addition, even when a small amount of water penetrates into the battery and the electrolyte and water react to decompose the electrolyte, the hydrofluoric acid is generated, and the protective layer 22 made of a polyvinyl alcohol-based resin laminated on the surface layer surface of the metal flat plate 21 is provided. Since there are few voids, the gas barrier property is high and the hydrofluoric acid which generate | occur | produced along the sealant layer 23 can be spread | diffused outside of a battery. In addition, even when a small amount of hydrofluoric acid comes into contact with the surface of the aluminum plate, which is the metal flat plate 21, corrosion of the metal flat plate 21 is prevented by the passivation film formed on the surface of the aluminum plate. The strength of the interlayer adhesion between the sealant layer 23 and the sealant layer 23 is maintained, so that the breakdown voltage strength can be maintained, so that the liquid leakage of the battery does not occur.

50-300 micrometers is preferable and, as for the thickness of the sealant layer 23 bonded to the surface of the protective layer 22, 50-150 micrometers is the most preferable. If the thickness of the metal flat plate 21 is 200 micrometers or more, since rigidity is strong, a through hole may arise in the side edge part (edge part) of the metal flat plate 21, and sealing of electrolyte solution may not be completed. Therefore, as shown in Fig. 4B, when viewed from the cross section along the junction with the packaging material, it is preferable that both ends 24 of the metal flat plate 21 are pressed to be thinner than the cross-sectional center portion. . Thereby, the thickness of the sealant layer 23 bonded to the surface of the protective layer 22 can be made thin.

0.1-5.0 micrometers is preferable and, as for the thickness of the protective layer 22 which consists of polyvinyl alcohol-type resins, More preferably, it is 0.5-3 micrometers. If the protective layer 22 is about this thickness, the performance of moisture resistance and adhesive strength will improve.

The protective layer 22 is formed in the required part of the outer surface of the metal flat plate 21 by the printing method. As a printing method, it is possible to use well-known printing methods, such as an inkjet system, a dispenser system, and a spray coating system. Although the printing method which can be used for this invention is arbitrary, since it is necessary to print not only the both surfaces of the metal flat plate 21 but also the side edge part (edge part) seen from the cross section of the electrode lead wire member, the inkjet method and the dispenser method are good. Particularly, in the dispenser method, an experiment was conducted using a coating head capable of printing with a narrow width of about 10 mm, and it was found that it was the most suitable method.

As the sealant layer 23 bonded to the surface of the protective layer 22 of the electrode lead wire member, it is preferable to use the same or similar resin film as the resin film 13 used for the innermost layer of the aluminum laminate film 10. Do. In the case of polypropylene in which the resin film 13 is generally used, the sealant layer 23 is a monomer having epoxy functional groups such as unstretched polypropylene (CPP), maleic anhydride modified propylene single film, or glycidyl methacrylate. It may be a single film of modified polypropylene, or a multilayer film with polypropylene. Even when the resin film 13 is polyethylene, the sealant layer 23 may be a single polyethylene modified with a monomer having an epoxy functional group such as polyethylene, maleic anhydride-modified polyethylene, or glycidyl methacrylate. The multilayer film of this and polyethylene and its copolymer may be sufficient. In this case, polyethylene modified with maleic anhydride, acrylic acid copolymer, glycidyl methacrylate, or the like may be used on the surface in contact with the electrolyte solution.

As a non-aqueous battery used for this invention, what used the organic electrolyte for electrolyte solutions, such as a lithium ion battery which is a secondary battery, an electric double layer capacitor, is mentioned. As the organic electrolyte, carbonate esters such as propylene carbonate (PC), diethyl carbonate (DEC), and ethylene carbonate are generally used as a medium, but are not particularly limited thereto.

(Example)

(How to measure)

-Measurement method of the adhesive strength between the metal flat plate and the sealant layer of the electrode lead wire member: JIS C6471 "Copper laminated sheet test method for flexible printed wiring boards using the measurement sample which heat-sealed the aluminum laminate film on the sealant layer. It measured by the measuring method prescribed by "."

Method for measuring electrolyte strength retention: PC / DEC electrolyte solution made of a 50 × 50 mm (heat seal width of 5 mm) quadrant bag using a battery packaging laminate and containing 1 mol / liter of LiPF ₆ therein. 0.5 wt% of pure water was added to the mixture, weighed 2 s, filled and packed. In this four bag, the protective layer was printed by the dispenser system to a part of outer surface of the metal flat plate of an electrode lead wire member. The electrode lead wire member which the sealant layer was laminated | stacked by the heat seal was put on this protective layer, and after storing for 100 hours in 60 degreeC oven, the interlayer adhesive strength k2 of the protective layer of an electrode lead wire member and a sealant layer is measured.

Here, the ratio of the interlayer adhesive strength (k1) between the protective layer before exposure to the electrolyte solution measured beforehand, and the polypropylene (PP) film which is a sealant layer, and the interlayer adhesive strength (k2) after exposure to electrolyte solution is electrolyte solution. Strength retention K = (k2 / k1) x100 (%) was made.

(Measuring device)

Adhesive Strength Measuring Device: Shimadzu Seisakusho, Model: AUTOGRAPH AGS-100A Tensile Test Device

(Example 1)

As a metal flat plate of the electrode lead wire member for lithium batteries, the aluminum piece which cut the aluminum plate whose thickness is 200 micrometers to the dimension of 50 mm x 60 mm was used. The thickness after drying using the aqueous solution which melt | dissolved 3 wt% of polyvinyl alcohol-type resin (made by Nippon Kosei Chemical Co., Ltd., brand name: G polymer resin) and 1 wt% of chromium (III) fluoride on the surface of this aluminum piece degreased-washed Both surfaces were applied by a 10 mm wide dispenser so as to have a thickness of 1 μm, and a protective layer was laminated. Furthermore, it heat-dried in 200 degreeC oven, baked the resin of a protective layer, and simultaneously crosslinked. At this time, it was confirmed that the protective layer was formed not only on the surface layers of both surfaces of the metal flat plate, but also on the side edges (both end surfaces) of the metal flat plate.

Moreover, on the surface of the protective layer of the outer surface of this metal flat plate, the single-layer film (polypropylene-type resin of Mitsui Chemicals, product name / adma QE060 from a maleic anhydride modified film is formed into 100 micrometers with a film making machine). Using one film) was bonded on both sides with a heat seal to obtain an electrode lead wire member of Example 1.

The electrode of Example 1 by heat-sealing the aluminum laminate film of 120 micrometers which consists of aluminum foil (thickness 20 micrometers) / maleic anhydride modified polypropylene film (thickness 100 micrometers) on the sealant layer of the electrode lead wire member of Example 1 The measurement sample using the lead wire member was produced.

The test piece for measuring the adhesive strength was taken from the measurement sample of Example 1, and the adhesive strength between the metal flat plate and the sealant layer was measured. As a result, the adhesive strength of 46 N / inch was shown.

In addition, the result of measuring electrolyte strength retention K about the measurement sample of Example 1 was K = 88%.

(Example 2)

As a metal flat plate of the electrode lead wire member for lithium batteries, nickel sulfamic acid plating is performed in the thickness of 2-5 micrometers on the surface of the copper plate piece (dimensions 50mm x 60mm) whose thickness is 200 micrometers, and the polyvinyl alcohol system is a part of it. The resin (Nippon Kosei Chemical Co., Ltd. make, brand name: G polymer resin) was apply | coated so that thickness after drying might be set to 1 micrometer using the aqueous solution which melt | dissolved 3 wt% and 1 wt% of chromium (III) fluoride, and laminated | stacked the protective layer. Furthermore, it heat-dried in 200 degreeC oven, baked the resin of a protective layer, and simultaneously crosslinked.

Moreover, the film which formed into 100 micrometers the film of the maleic anhydride modified polypropylene film single layer (polypropylene-type resin, Mitsui Chemicals / Adma QE060 by Mitsui Chemicals, Inc. on the surface of the protective layer of the outer surface of this metal flat plate by a film making machine). ) Was double-sided thermal bonding by heat sealing to obtain an electrode lead wire member of Example 2.

An aluminum laminate film was heat-sealed in the same manner as in Example 1 using the electrode lead wire member of Example 2 to obtain a measurement sample of Example 2, and the adhesion strength between the metal flat plate and the sealant layer was measured. Strength was shown.

Moreover, the result of having measured electrolyte solution strength retention K about one part of battery storage container of Example 2 was K = 78%.

(Example 3)

As an aqueous solution to be applied to a part of the metal flat plate, an aqueous solution obtained by dissolving 2 wt% of polyvinyl alcohol-based resin (manufactured by Nippon Sakubi Pobaru Co., Ltd., product name: J-Pobaru DF-20) and 2 wt% of chromium fluoride (III) The electrode lead wire member and the measurement sample of Example 3 were obtained like Example 2 except having apply | coated so that the thickness after drying might be set to 0.8 micrometer using, and the protective layer was laminated | stacked.

The adhesive strength of the metal flat plate and the sealant layer was measured about the electrode lead wire member and the measurement sample of Example 3, and the adhesive strength of 44 N / inch was shown.

Moreover, the result of having measured electrolyte solution strength retention K about one part of battery storage container of Example 3 was K = 74%.

(Example 4)

Thickness after drying using the aqueous solution which melt | dissolved 2 wt% of polyvinyl alcohol-type resin (made by Nippon Kabaido Kogyo Co., Ltd., brand name: Crosmer H) and 2 wt% of chromium (III) fluoride as aqueous solution apply | coated to a part of metal plate. The electrode lead wire member and the measurement sample of Example 4 were obtained like Example 2 except having apply | coated so that it might become 0.8 micrometer, and laminating | stacking a protective layer.

The adhesive strength of the metal flat plate and the sealant layer was measured with respect to the electrode lead wire member and the measurement sample of Example 4, and the adhesive strength of 46 N / inch was shown.

Moreover, the result of having measured electrolyte solution strength retention K about one part of battery storage container of Example 4 was K = 77%.

(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 protective layer was not laminated on the aluminum plate, and the adhesion strength between the metal flat plate and the sealant layer was measured. Adhesive strength was shown. In addition, the result of having measured electrolyte solution strength retention K about the measurement sample of the comparative example 1 was K = 10% or less.

(Comparative Example 2)

As a metal flat plate of the electrode lead wire member for lithium batteries, about 2-5 micrometers nickel sulfamic acid plating is performed on the surface of the copper-plate piece (size 50mm x 60mm) of 200 micrometers in thickness, and polyvinyl alcohol-type resin is a part of it. (Nippon Kosei Chemical Co., Ltd. make, brand name: G polymer resin) was apply | coated so that the thickness after drying might be set to 1 micrometer using the coating material which mixed 3 weight% and 1 weight% of chromium (III) fluoride, and laminated | stacked the protective layer. 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 heat drying treatment was not performed after the lamination.

The adhesion strength between the metal flat plate and the sealant layer was measured for the electrode lead wire member and the measurement sample of Comparative Example 2, and exhibited an adhesion strength of 46 N / inch. In addition, the result of having measured electrolyte solution strength retention K about the measurement sample of the comparative example 2 was K = 10% or less. Since it was exposed to electrolyte solution after the measurement of electrolyte solution strength retention rate, the metal plate of the electrode lead wire member, and the sealant layer caused the delamination.

The above result is put together in Table 1 and shown. In Table 1, "the adhesive strength of the metal flat plate of an electrode lead wire member and a sealant layer" was simply called "adhesive strength."

As Example 1 and Example 2, Nippon Kosei Chemical Co., Ltd. make, brand name: G polymer resin were used as polyvinyl alcohol-type resin. Example 3 used Nippon Sakubi Pobaru Co., Ltd. product, brand name: J-Pobaru DF-20 as polyvinyl alcohol-type resin. In Example 4, Nippon-Kabido Kogyo Co., Ltd. make, brand name: Crossmer H series were used as polyvinyl alcohol-type resin. In Examples 1 to 4, a protective layer was formed by coating a polyvinyl alcohol-based resin on a metal plate of an electrode lead wire member using a paint obtained by mixing 3 wt% or 2 wt% and chromium (III) fluoride (1 wt% or 2 wt%). Therefore, the adhesive strength between the metal flat plate and the sealant layer of the electrode lead wire member is 40 N / inch or more. Moreover, the electrode lead wire member which apply | coated the protective layer between the sealant layer and the metal plate was also resistant to the electrolyte solution of a lithium battery, and was also high withstand voltage strength.

On the other hand, although the protective layer was not formed in the electrode lead wire member in Comparative Example 1, the adhesive strength between the metal flat plate and the sealant layer of the electrode lead wire member showed a high value of 54 N / inch. However, electrolyte strength retention K is 10% or less, and there is no electrolyte resistance.

In addition, although the heat drying was not performed even if the protective layer was apply | coated to the electrode lead wire member, the comparative example 2 was 46 N / inch of the adhesive strength of the metal flat plate and the sealant layer of the electrode lead wire member. However, electrolyte strength retention K is 10% or less, and there is no electrolyte resistance.

10... Battery exterior laminate, 11... Substrate 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... Metal plate, 22... Protective layer, 23.. Sealant layer, 30... Battery mounting container, 35... Battery storage container

Claims (7)

An electrode lead wire member drawn out from a storage container for non-aqueous batteries using a laminate film laminate of an aluminum foil and a resin film as an exterior material, and is made of polyvinyl alcohol-based resin or polyvinyl ether-based resin on the outer surface of a flat metal plate. An electrode lead wire member in which a protective layer is formed by coating and drying a solution containing a resin and a fluorine compound. The method of claim 1,
The electrode lead wire member in which the said fluorine compound is water-soluble. 3. The method according to claim 1 or 2,
The electrode lead wire member in which the said protective layer is formed in the strip | belt-shaped pattern by printing on the outer surface of the said metal flat plate. 3. The method according to claim 1 or 2,
An electrode lead wire member, wherein the protective layer is crosslinked or amorphous by heat treatment, and has water resistance. The storage container for non-aqueous batteries in which the electrode lead wire member of Claim 1 or 2 was used. A storage container for a non-aqueous battery in which the electrode lead wire member of claim 3 is used. A storage container for a non-aqueous battery in which the electrode lead member of claim 4 is used.

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