JP2003036823A - Battery packaging material - Google Patents

Abstract

(57) [Problem] To provide a battery packaging material which improves the content resistance of a barrier layer in a battery packaging material, and has stable workability and good content protection. A packaging material for forming a battery exterior body in which a battery body is inserted and a peripheral portion is sealed by heat sealing is composed of at least a base layer, an adhesive layer 1, a barrier layer, an adhesive layer 2, and a sealant layer. A battery packaging material, which is a laminate, wherein at least the surface of the barrier layer is formed of nickel.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The battery packaging material of the present invention comprises:
Used for batteries with liquid or solid organic electrolytes (polymer electrolytes) that have moisture resistance and content resistance, or for fuel cells, capacitors, capacitors, etc., and the barrier layer of the outer casing is generated by the reaction between the electrolyte and moisture. The present invention relates to a packaging material for a battery, which is resistant to corrosion by hydrogen fluoride and has good storage stability.

[0002]

2. Description of the Related Art The battery in the present invention means a material including an element for converting chemical energy into electric energy, such as a lithium ion battery, a lithium polymer battery, a fuel cell, etc., or a liquid, a solid ceramic, an organic material. Electrolytic capacitors such as liquid capacitors, solid capacitors, double-layer capacitors, etc. containing dielectrics such as The batteries can be used as personal computers, mobile terminal devices (mobile phones, PDAs).
Etc.), video cameras, electric vehicles, energy storage batteries, robots, satellites, etc. As the outer casing of the battery, a metal can obtained by pressing a metal into a cylindrical or rectangular parallelepiped container, or a laminate made of a composite film obtained by laminating a plastic film, a metal foil or the like into a bag shape. What was done (the following, an exterior body) was used. The battery exterior body has the following problems. In a metal can, the shape of the battery itself is determined because the outer wall of the container is rigid. Therefore, since the hardware side is designed to match the battery, the size of the hardware using the battery is determined by the battery, and the degree of freedom in shape is reduced. Therefore, there is a tendency to use the bag-shaped exterior body. The material constitution of the outer package is composed of at least a base material layer, a barrier layer, a heat seal layer and an adhesive layer for adhering each of the layers, in view of necessary physical properties, processability, economical efficiency, etc. as a battery, and if necessary, an intermediate A layer may be provided. A pouch is formed from the laminated body having the above-mentioned structure of the battery, or at least one surface is press-molded to form a battery housing portion for housing the battery body, and is a pouch type or an embossed type (covering the lid body). In the above, a battery is obtained by sealing necessary portions of each peripheral edge by heat sealing.

[0003]

However, in the laminated body forming the battery packaging material, when the barrier layer is made of a material such as aluminum or copper, it is generated by the reaction between the electrolyte and the moisture of a lithium ion battery or the like. Hydrogen fluoride (HF) or the like may penetrate through the sealant layer and reach the surface of aluminum or copper which is the barrier layer made of the above material, and corrode the surface of the barrier layer made of these metals. When the corrosion of the barrier layer surface progresses, it causes delamination between the barrier layer and the sealant layer, and when the corrosion progresses further, it causes pinholes in the barrier layer and loses its function as a packaging material. become. Therefore, the present inventors have found that a chromate treatment is applied to the surface of the barrier layer to improve the content resistance, but the present inventors have found that the aluminum which is the barrier layer 12 of the battery packaging material is aluminum. It is found and proposed to solve the content resistance by forming a laminate satisfying the packaging material by subjecting the front and back surfaces to a chemical conversion treatment. The chemical conversion treatment is, specifically, by forming an acid resistant film of a phosphate, a chromate, a fluoride, a triazine thiol compound, etc., to delaminate the aluminum and the base material layer during embossing. Prevention,
Hydrogen fluoride generated by the reaction between the battery electrolyte and water prevents dissolution and corrosion of the aluminum surface, especially aluminum oxide present on the aluminum surface, and prevents adhesion of the aluminum surface ( Wettability)
The effect of preventing delamination between the base material layer and aluminum during embossing and heat sealing, and the effect of preventing delamination on the inner surface side of aluminum by hydrogen fluoride generated by the reaction between the electrolyte and water were obtained. Among the above acid-resistant film-forming substances, the phosphoric acid chromate treatment using one composed of a phenol resin, a chromium fluoride (3) compound, and phosphoric acid is a processability,
It showed a stable effect on corrosion resistance. However, it is preferable to avoid the use of the phosphate, chromate, fluoride, etc. in the chromate treatment because of the fear of environmental pollution, and the chromate treatment causes an increase in processing cost. An object of the present invention is to improve the content resistance of the barrier layer in a battery packaging material, and to provide a battery packaging material with stable processability and good content protection.

[0004]

The above-mentioned problems can be solved by the present invention described below. In the invention described in claim 1, the packaging material forming the outer casing of the battery, in which the battery main body is inserted and the peripheral portion is sealed by heat sealing, is at least a base material layer, an adhesive layer 1, a barrier layer, an adhesive layer 2, and a sealant. It is a laminated body composed of layers, and is made of a packaging material for a battery, wherein at least the surface of the barrier layer is formed of nickel. The invention described in claim 2 is characterized in that the barrier layer according to claim 1 is made of nickel foil. The invention described in claim 3 is characterized in that the barrier layer described in claim is made of nickel-plated aluminum foil.
The invention described in claim 4 is characterized in that the barrier layer described in claim 1 is made of nickel-plated copper foil. The invention described in claim 5 is,
The adhesive layer 1 and the adhesive layer 2 according to claim 4.
Is formed by a dry laminating method. The invention described in claim 6 is,
The adhesive layer 2 according to claim 4 is a coating and baking layer of an acid-modified polyolefin. The invention described in claim 7 is characterized in that the adhesive layer 2 described in any one of claims 1 to 4 is an extruded layer of an acid-modified polyolefin.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION The packaging material for a battery of the present invention comprises at least a base material layer, an adhesive layer, a barrier layer, an adhesive layer, and a sealant layer, and at least an outer package of the battery,
The surface of the barrier layer on the content side is a nickel layer. Hereinafter, the battery packaging material of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a diagram for explaining the battery packaging material of the present invention. (A) a barrier layer made of nickel foil, (b) a barrier layer having a nickel layer formed on one side, and (c) a nickel layer formed on both sides. Cross-sectional views of the respective barrier layers formed with (d)
(E) And (f) is sectional drawing of the laminated body of the packaging material for batteries which has each barrier layer of (a), (b), and (c) as a component. FIG. 2 is a cross-sectional view showing an example of the layer structure of a laminated body forming an outer casing of a battery. FIG. 3 is a perspective view illustrating a battery pouch-type exterior body. Figure 4
FIG. 3 is a perspective view illustrating an embossed type outer casing of a battery. 5A and 5B are (a) perspective views, (b) emboss-molded exterior body main body, (c) X ₂ -X ₂ section sectional view, and (d) Y ₁ section enlarged view for explaining the molding in the embossing type. is there. FIG. 6 is a diagram illustrating a method of mounting the lead wire film in bonding the battery packaging material and the lead wire.

The outer casing of the battery is required to have a property of maintaining the performance of the battery main body for a long period of time, and a base material layer, a barrier layer, a heat seal layer and the like are laminated by various laminating methods. In particular, for example, a battery body of a lithium-ion battery is housed in an exterior body that constitutes an exterior body (hereinafter referred to as an exterior body) of a battery in which the barrier layer of the laminate is made of a laminate such as aluminum, and the periphery thereof is sealed. When the battery is sealed as described above, when hydrogen fluoride permeates the sealant layer directly to the aluminum surface and reaches the aluminum surface, the aluminum surface is corroded. Corrosion causes delamination between the barrier layer and the sealant layer.

The inventors of the present invention have conducted earnest research on imparting properties such as corrosion protection to the surface of aluminum (content resistance), and as a result, at least the surface of the barrier layer of the battery packaging material on the content side. Found that the problem can be solved by using a barrier layer made of nickel,
The present invention has been completed. The barrier layer of the battery packaging material according to the present invention may be a nickel single layer, but since nickel foil has high rigidity, a laminate having nickel alone as a barrier layer is used as an exterior body (pouching, embossing). There is a problem in processing suitability at the time of processing, etc., and it is preferable to form a thin film of nickel on aluminum or copper foil. However, it is possible to use a laminated body having a nickel foil as a barrier layer for a lid or the like of an embossed type exterior body which is not subjected to the pouching or embossing.

The barrier layer in the battery packaging material of the present invention preferably has a structure in which a nickel plating layer is formed on at least one side, preferably both sides, of an aluminum or copper foil (hereinafter referred to as barrier layer substrate). The nickel plating layer provided for the purpose of preventing corrosion of the substrate is 10 to 80 μm.
A thickness of m is desirable. If the thickness of the nickel plating layer is less than 10 μm, the effect of preventing corrosion is not certain, and if the thickness of the nickel plating layer exceeds 80 μm, the formation of an outer package (pouching, embossing, etc.)
The workability in is worse.

As described above, the barrier layer substrate is formed of nickel foil or the nickel layer is formed on the surface of the barrier layer substrate, whereby the barrier layer substrate is produced by the reaction between the electrolytic solution of the battery and moisture. It is possible to prevent corrosion due to the like, and to obtain a battery packaging material without delamination of the laminate.

The battery main body is composed of a cell which is a power storage unit and a lead wire which draws current from the battery. The lead wire is made of an elongated plate-shaped or rod-shaped metal. For the plate-shaped lead wire, the thickness is 50 to 2000 μm and the width is about 2.5 to 20 mm.
AL, Cu, Ni, etc. After the battery packaging material is used as an exterior body, the battery body is inserted into or placed on the exterior body, and the periphery of the exterior body is heat-sealed to hermetically seal the battery body. A part is sealed so as to protrude to the outside of the exterior body. That is, in the heat-sealing of the periphery of the outer package, the heat-sealing is performed in the lead wire portion while the lead wire is sandwiched.

When the sealant layer 14 of the battery packaging material is made of a material having no heat-sealing property with respect to metal, the lead wire film 6 is interposed between the outer casing 5 and the lead wire 4. The method is, for example, as shown in FIG.
As shown in (a) and FIG. 6 (b), the lead wire film 6 is placed above and below the lead wire portion hermetically sealed portion of the battery body 2 (actually fixed by a temporary attachment seal)
And the lead wire part is sandwiched and heat-sealed to hermetically seal.

As a method of interposing the lead wire film 6 in the lead wire 4, as shown in FIG. 6D or 6E, the film of the lead wire film 6 is placed at a predetermined position of the lead wire 4. You may wrap it.

The layer thickness of the lead wire film 6 may be 1/3 or more of the thickness of the lead wire used, and for example,
If the lead wire has a thickness of 100 μm, the layer thickness of the lead wire film 6 may be about 30 μm or more.

Next, the material of the battery packaging material of the present invention will be described. As shown in FIG. 2 (a), FIG. 2 (b), and FIG. 2 (c), the battery packaging material includes at least a base material layer 11, an adhesive layer 16, a barrier layer 12, an adhesive layer 13, and a sealant layer 14. It is composed of However, FIG.
The barrier layer in 1 is shown as a single layer.

When the lead wire film is used, specifically, a film made of an acid-modified polyolefin having thermal adhesiveness is used for both the sealant layer of the outer package and the lead wire. The acid-modified polyolefin resin is an unsaturated carboxylic graft polyolefin, and others,
As the lead wire film, metal crosslinked polyethylene,
It is also possible to use a copolymer of ethylene and an acrylic acid or methacrylic acid derivative, a simple substance of a copolymer of ethylene and vinyl acetate, or a blend thereof.

The battery packaging material forms an exterior body for packaging the battery body. Depending on the type of the exterior body, a pouch type as shown in FIG. 3 and FIGS. 4 (a) and 4 (b) are provided. ) Or an embossed type as shown in FIG. The pouch type includes a bag type such as a three-sided seal, a four-sided seal, and a pillow type.
Is illustrated as a pillow type. As shown in FIG. 4 (a), the embossed type may have a recess formed on one side, or as shown in FIG. 4 (b), a recess may be formed on both sides to accommodate the battery main body and to accommodate the peripheral edge. The four sides may be heat-sealed and sealed. In addition, there is also a type in which recesses are formed on both sides by sandwiching a folded portion as shown in FIG. 4 (c) to accommodate a battery and heat seal three sides. When the battery packaging material is an embossed type, as shown in FIGS. 5A to 5D, the stacked packaging material 10 is press-molded to form the recess 7.

As shown in FIG. 2A, the battery packaging material of the present invention is a laminate composed of at least a base material layer 11, an adhesive layer 16, a barrier layer 12, an adhesive layer 13, and a sealant layer 14. is there.

Next, each layer constituting the battery packaging material of the present invention will be described. The base material layer 11 in the exterior body
Is a stretched polyester or nylon film, and examples of the polyester resin include polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, copolyester, and polycarbonate. As nylon, polyamide resin, that is, nylon 6, nylon 6,6, nylon 6 and nylon 6,6
And nylon 6,10, polymeta-xylylene adipamide (MXD6), and the like. The base material layer 1
In the case of being used as a battery, the reference numeral 1 is basically a resin layer having an insulating property because it is a portion that directly contacts the hardware. Considering the existence of pinholes in the film itself and the occurrence of pinholes during processing, the base material layer needs to have a thickness of 6 μm or more, and the preferable thickness is 12 to 3
It is 0 μm.

The base material layer 11 may be laminated in order to improve the pinhole resistance and the insulating property when used as an outer casing of a battery. When the base material layer is laminated, the base material layer includes at least one resin layer of two or more layers, and the thickness of each layer is 6 μm or more, preferably 12 to 30 μm. Examples of laminating the base material layer include the following 1) to 8). 1) Stretched polyethylene terephthalate / stretched nylon 2) Stretched nylon / stretched stretched polyethylene terephthalate In addition, mechanical suitability of packaging materials (stability of conveyance in packaging machines and processing machines), surface protection (heat resistance, electrolyte resistance) ) Protecting the base material layer for the purpose of reducing the frictional resistance between the die and the base material layer during embossing or when the electrolytic solution adheres when the battery exterior body is embossed as the secondary processing. In order to make the base material layer multi-layered, on the base material layer surface, a fluororesin layer, an acrylic resin layer, a silicone resin layer, a polyester resin layer, oleic acid amide, erucic acid amide, bisoleic acid amide, etc. It is preferable to provide a resin layer or the like made of a slip agent or a blend thereof. For example, 3) Fluorine-based resin / stretched polyethylene terephthalate (fluorine-based resin is a film-like material or is formed by drying after liquid coating) 4) Silicone-based resin / stretched polyethylene terephthalate (silicone-based resin is a film-like material or liquid) Formed by drying after coating) 5) Fluorine resin / stretched polyethylene terephthalate /
Stretched nylon 6) Silicone resin / stretched polyethylene terephthalate / stretched nylon 7) Acrylic resin / stretched nylon (acrylic resin is film-like or liquid coating and cured by drying) 8) Acrylic resin + polysiloxane graft acrylic resin / Stretched nylon (Acrylic resin is film,
Or liquid coating and drying to cure)

The barrier layer 12 or the barrier layer base 12
b is a layer for preventing water vapor from entering the inside of the battery from the outside, which stabilizes the pinhole of the barrier layer itself and the processability (pouching, embossing moldability), and the pinhole resistance. A metal having a thickness of 15 μm or more, such as aluminum, copper, or nickel, or
A film obtained by vapor-depositing an inorganic compound such as silicon oxide or alumina can be used, but the barrier layer substrate 12b is preferably aluminum having a thickness of 20 to 80 μm. In order to further improve the generation of pinholes and to prevent the occurrence of cracks during embossing when the type of the battery exterior body is embossed, the inventors of the present invention used aluminum as the barrier layer substrate 12b. When used, the material has an iron content of 0.3 to 9.0% by weight, preferably 0.7 to 2.0% by weight, as compared with aluminum containing no iron, It has been found that aluminum has good spreadability, the occurrence of pinholes due to bending as a laminated body is reduced, and the side wall can be easily formed when molding the embossed type outer casing. When the iron content is less than 0.3% by weight, effects such as prevention of pinholes and improvement of embossing formability are not observed, and the iron content of the aluminum exceeds 9.0% by weight. In this case, the flexibility as aluminum is impaired and the bag-making property as a laminate is deteriorated.

Aluminum produced by cold rolling has its flexibility and flexibility under annealing (so-called annealing) conditions.
Although the strength / hardness of the waist changes, the aluminum used in the present invention is
Aluminum, which tends to be soft with some or complete annealing, is preferred. The degree of flexibility, waist strength, and hardness of aluminum, that is, the annealing condition, is
It may be appropriately selected depending on the workability (pouching, embossing). For example, in order to prevent wrinkles and pinholes during embossing, it is desirable to use annealed soft aluminum according to the degree of molding.

As described above, the present inventors use nickel as the barrier layer 12 of the battery packaging material, or use aluminum or copper as the barrier layer base 12b, and form the nickel layers 15 on the front and back surfaces thereof. By doing so, it was possible to obtain a laminate that was satisfactory as the above-mentioned battery packaging material.

When aluminum or copper is used as the substrate 12b of the barrier layer and the nickel layer 15 is formed on the front and back surfaces thereof, when the exterior body is a pouch type, the nickel layer 15 is formed on one side only on the heat seal layer side or Both of the base layer side and the heat seal layer side may be used. When the outer casing of the battery is an embossed type, as shown in FIG. 1C, the nickel layer 15 is formed on both surfaces of the barrier layer substrate 12b.
By forming (1) and 15 (2), delamination between the barrier layer 12 and the base material layer 11 at the time of embossing can be prevented.

In the sealant layer 14 of the battery packaging material of the present invention, the sealant layers (at least the innermost layer S3 in the case of multiple layers) can be heat-sealed, and the performance of the battery can be maintained for a long time by sealing. The material of the sealant is not limited as long as it satisfies the basic requirements of the sealant, such as no problem in using the battery.
The sealant layer 14 may be a single layer or a multilayer structure containing different materials as shown in FIG. As the material used as a sealant,
Specifically, as the polyethylene-based resin, a low-density polyethylene, a medium-high-density polyethylene, a linear low-density polyethylene, a polyethylene or a layer obtained by graft-polymerizing an unsaturated carboxylic acid, or a layer composed of multiple layers, or a propylene-based resin , A homotype, a copolymer of ethylene and propylene, a copolymer of ethylene, propylene and butene, a simple substance of polypropylene grafted with an unsaturated carboxylic acid, or a layer composed of a single layer or multiple layers using a blended product, etc. Can be used. Further, the butane component, the terpolymer component made of a three-component copolymer of ethylene, butene and propylene, and the density of 900 kg are used for the sealant layer 14 made of polypropylene resin and the adhesive resin layer.
It is also possible to add a low crystalline ethylene / butene copolymer, an amorphous ethylene / propylene copolymer, and a propylene α / olefin copolymer component having a crystallinity of 1 / m ³ .

When the packaging material for a battery of the present invention is laminated, the adhesion between the nickel layer 15 formed on the surface of the barrier layer and the sealant layer 14 is caused by, for example, reaction between the electrolytic solution and water in a lithium ion battery or the like. In order to prevent delamination due to hydrofluoric acid or the like generated by the above, it is desirable to perform the laminating and adhesion stabilizing treatments described below.

As a result of earnest research on a laminating method showing stable adhesive strength, the present inventors have shown that FIG. 2 (a) shows that after at least the barrier layer 12 laminating the sealant layer and the base material layer 11 are dry laminated. As shown, as a method of adhering the nickel foil (or the nickel layer 15 formed on the surface of the barrier layer substrate 12b) and the sealant layer 14, a laminate 13d is performed by a dry laminating method, or, as shown in FIG. 2 (b), It was also confirmed that a predetermined adhesive strength could be obtained by applying an emulsion of acid-modified polyolefin to the nickel layer, followed by drying and baking (13h), and then laminating the film 14 to be the sealant layer by a thermal laminating method. Note that in FIG. 2A, the sealant layer has two layers, and the sealant layer shown in FIG.
In (c), the sealant layer is illustrated as three layers.

It was also confirmed that stable adhesive strength can be obtained by the following laminating method. For example, the base material layer 11 and one surface of the barrier layer 12 are dry-laminated, and the acid-modified polyolefin 13e is formed on the other surface (nickel forming layer) of the barrier layer 12 as shown in FIG. 2C.
Is extruded to sandwich laminate the sealant layer 14 to form a laminate, or after the acid-modified polyolefin resin 13 and the sealant layer are co-extruded to form a laminate, the obtained laminate is formed into the acid-modified polyolefin resin. 1
By heating under the condition that 3e is equal to or higher than the softening point, a laminate having a predetermined adhesive strength could be obtained. Specific methods of heating include hot roll contact type, hot air type, near or far infrared rays, etc., but any heating method may be used in the present invention, and as described above, the adhesive resin softens. It suffices if it can be heated above the point temperature. It is also possible to use polyethylene resin as the adhesive resin, but in this case, it is desirable to laminate while laminating the aluminum-side laminating surface of the extruded polyethylene molten resin film.

In the battery packaging material of the present invention, each of the above-mentioned layers in the laminate forming the outer package has appropriate film-forming properties, lamination processing, and final product secondary processing (pouching, embossing) suitability. For the purpose of improving and stabilizing, surface activation treatment such as corona treatment, blast treatment, oxidation treatment and ozone treatment may be performed.

[0030]

EXAMPLES The battery packaging material of the present invention will be described in more detail with reference to examples. (1) Exterior body type In the examples and comparative examples, the pouch-type exterior body has a width of 30 mm and a length of 50 mm (both inner dimensions).
In addition, in the case of the embossed type exterior body, all were single-sided embossed type, and the shape of the recess (cavity) of the forming die was 30 mm × 50 mm and the depth was 3.5 mm, and press forming was performed to evaluate the formability. . In each of the examples of the embossed type, the unmolded laminated body was used as the lid body. (2) The nickel plating has a thickness of 20 μm, and in the case of single-sided plating, the surface to be plated with aluminum is the surface on the sealant layer side of aluminum. (3) Delamination Confirmation Liquid The delamination confirmation liquid to be enclosed in the outer casings formed in Examples and Comparative Examples in order to confirm the presence or absence of leakage and delamination was electrolytic solution 1M LiPF ₆ . Mixture of ethylene carbonate, diethyl carbonate and dimethyl carbonate (1: 1: 1), 3
g. And (3) Heat-sealing conditions The heat-sealing conditions for housing the battery main body in an outer package and sealing the peripheral edge of the outer package were performed under the following conditions in both Examples and Comparative Examples. Heat sealing conditions 190 ° C, 1.0 MPa, 3.0 s
ec [Example 1] Nickel plating on one side of aluminum 20 µm, stretched polyester film 12 µm (1) is adhered on the surface not plated with nickel by dry lamination method, and then dry lamination is performed on the other surface of nickel plated aluminum. A stretched polyester film 12 μm (2) was laminated by the method, and an ethylene methacrylic acid resin was extruded on the surface of the stretched polyester film 12 μm (2) to a thickness of 50 μm to form a sealant layer to obtain a laminate. A pouch-type exterior body was formed from the obtained laminated body, and then the delamination confirmation liquid was filled in the pouch and then hermetically sealed by heat sealing to obtain Sample Example 1. Example 2 Nickel plating on one surface of aluminum of 20 μm, stretched polyester film 12 μm (1) on the surface not plated with nickel by dry laminating method, then acid-modified polypropylene on the other surface of nickel-plated aluminum As an adhesive resin 15 μm
The thickness was extruded, and cast polypropylene (hereinafter, CPP) 30 for the sealant layer was sandwich-laminated to obtain a laminate. After forming a pouch with the laminate obtained by heating the laminate to a temperature not lower than the softening point of the acid-modified polypropylene, the pouch was filled with the delamination confirmation liquid and then hermetically sealed by heat sealing to obtain Sample Example 2. Obtained. [Example 3] Both sides of aluminum having a thickness of 40 µm were nickel-plated, and a stretched nylon film 25 µm was attached to one surface having a nickel plating layer by a dry lamination method. CPP film 3 to be a sealant layer on the surface
0 μm was dry laminated to obtain a laminate. A tray was molded using the obtained laminated body, and a laminated body that was not molded was used as a lid. After filling the tray with the delamination confirmation liquid, the lid was covered and the peripheral edge was hermetically sealed by heat sealing to obtain a sample Example 3. Example 4 Nickel plating was applied to both sides of aluminum 40 μm, and a stretched nylon film 25 μm was attached to one surface having a nickel plating layer by a dry lamination method, and then another aluminum having a nickel plating layer was applied. CPP film 30μ, which will be the sealant layer by extruding acid-modified polypropylene that will be the adhesive resin layer on the surface
m was sandwich-laminated, and the obtained laminate was heated to a temperature not lower than the softening point of the acid-modified polypropylene to form a tray, and the unformed laminate was used as a lid. After filling the tray with the delamination confirmation liquid, the lid was covered, and the periphery was hermetically sealed by heat sealing to obtain a sample Example 4. [Example 5] Nickel plating was applied to both sides of aluminum 40 µm, and a stretched nylon film 25 µm was attached to one side having a nickel plating layer by a dry lamination method, and then another aluminum having a nickel plating layer was applied. An emulsion of acid-modified polypropylene was applied to the surface and dried, and then a coating layer was formed by baking at a temperature of 190 ° C., and a CPP film having a thickness of 30 μm to be a sealant layer was thermally adhered to the coating. A tray was molded using the obtained laminated body, and a laminated body that was not molded was used as a lid. After filling the tray with the delamination confirmation liquid, the lid was covered and the peripheral edge was hermetically sealed by heat sealing to obtain a sample Example 5. Example 6 Nickel plating was applied to both sides of a copper foil 40 μm, and a stretched nylon film 25 μm was attached to one side having a nickel plating layer by a dry lamination method, and then aluminum having a nickel plating layer was used. A CPP film 30 μm to be a sealant layer was dry-laminated on the surface of 1 to obtain a laminate. A tray was molded using the obtained laminated body, and a laminated body that was not molded was used as a lid.
After filling the tray with the delamination confirmation liquid, the lid was covered and the peripheral edge was hermetically sealed by heat sealing to obtain a sample Example 6. [Example 7] Nickel plating was applied to both sides of a copper foil 40 µm, and a stretched nylon film 25 µm was attached to one surface of the copper foil provided with the nickel plating layer by a dry lamination method, and then a nickel plating layer was provided. On the other side of the copper foil, an acid-modified polypropylene that will be the adhesive resin layer is extruded and a CPP film 30 μm that will be the sealant layer is sandwich-laminated, and the resulting laminate is heated to a temperature above the softening point of the acid-modified polypropylene. A tray was formed using the obtained laminated body, and the unformed laminated body was used as a lid. After filling the tray with the delamination confirmation liquid, the lid was covered and the peripheral edge was hermetically sealed by heat sealing to obtain a sample Example 7. Example 8 Nickel plating was applied to both sides of a copper foil 40 μm, and a stretched nylon film 25 μm was attached to one surface of the copper foil provided with the nickel plating layer by a dry lamination method, and then a nickel plating layer was provided. An acid-modified polypropylene emulsion is applied to the other surface of the copper foil and dried, and then a film layer having a thickness of 5 μm is formed by baking at a temperature of 190 ° C., and a CPP film having a thickness of 30 μm to be a sealant layer is formed on the film. Was heat-bonded. A tray was molded using the obtained laminated body, and a laminated body that was not molded was used as a lid. After filling the tray with the delamination confirmation liquid, the lid was covered and the peripheral edge was hermetically sealed by heat sealing to obtain a sample Example 8.

Comparative Example 1 Untreated aluminum 20 μm
12 μm (1) of the stretched polyester film is adhered to one surface of the same by a dry lamination method, then 12 μm (2) of the stretched polyester film is laminated to the other surface of aluminum by a dry lamination method, and further, a stretched polyester film 12 μm ( An ethylene methacrylic acid resin was extruded on the surface of 2) to a thickness of 50 μm to form a sealant layer to obtain a laminate. After forming a pouch with the obtained laminated body, the battery main body was housed in the pouch and hermetically sealed by heat sealing to obtain a sample comparative example 1. [Comparative Example 2] A stretched polyester film of 12 µm was laminated on one surface of untreated aluminum of 40 µm by a dry lamination method, and then on the other surface of aluminum,
Using a laminate obtained by extruding an acid-modified polypropylene to be an adhesive resin layer and sandwich-laminating a CPP film 50 μm to be a sealant layer, and heating the obtained laminate to a temperature not lower than the softening point of the acid-modified polypropylene. The tray was molded, the laminated body not molded was used as a lid, the tray was filled with the delamination confirmation liquid, the lid was covered, and the peripheral edge was hermetically sealed by heat sealing to obtain a sample comparative example 2. [Comparative Example 3] A stretched nylon film (25 µm) was attached to one surface of an untreated copper foil (40 µm) by a dry lamination method, and then an acid-modified polypropylene emulsion was applied to the other surface of the copper foil and dried. A film layer baked at a temperature of 190 ° C. was formed, and a CPP film having a thickness of 30 μm to be a sealant layer was thermally adhered to the film layer. A tray was molded using the obtained laminated body, and a laminated body that was not molded was used as a lid. After filling the tray with the delamination confirmation liquid, the lid was covered and the peripheral edge was hermetically sealed by heat sealing to obtain a sample comparative example 3.

<Evaluation Method> (1) Confirmation of Leakage and Delamination (Hereinafter, Delamination) Each sample in which the delamination confirmation liquid was sealed was stored at 80 ° C. for 24 hours to confirm leakage and delamination.

<Results> In each of Examples 1 to 8,
There was no leak and no delamination. No leakage was observed in Comparative Example 1, Comparative Example 2 and Comparative Example 3, but delamination was confirmed at the interface between the aluminum and the stretched polyester film. The degree of delamination was highest in Comparative Example 1, followed by Comparative Example 3 and Comparative Example 2.

[0034]

EFFECTS OF THE INVENTION Hydrogen fluoride (HF) generated by a reaction between an electrolyte and water is obtained by using an outer package made of a battery packaging material characterized in that at least the surface of the barrier layer is formed of nickel. It has a remarkable effect of preventing the corrosion of the barrier layer due to. Also,
When the sealant layer is formed by a dry laminating method, a thermal laminating method, or a sandwich laminating method or a coextrusion laminating method, by heating during the formation of the laminated body or after the laminated body is formed, aluminum It is an exterior body that can also prevent delamination with a layer on the contents side.

[Brief description of drawings]

FIG. 1 is a diagram illustrating a battery packaging material of the present invention,
(A) A barrier layer made of a nickel foil, (b) a barrier layer having a nickel layer formed on one side, (c) respective cross-sectional views of the barrier layer having a nickel layer formed on both sides, (d), (e) and (f). [Fig. 3] is a cross-sectional view of a laminate of a battery packaging material including the barrier layers of (a), (b), and (c) as constituent elements.

FIG. 2 is a cross-sectional view showing an example of a layer structure of a laminated body forming an outer casing of a battery.

FIG. 3 is a perspective view illustrating a pouch-type exterior body of a battery.

FIG. 4 is a perspective view illustrating an embossed type outer casing of a battery.

FIG. 5 illustrates molding in an embossed type,
(A) perspective view, (b) embossed outer casing body,
(C) X ₂ -X ₂ parts cross-sectional view, an enlarged view (d) Y ₁ parts.

FIG. 6 is a diagram illustrating a method of mounting a lead wire film in bonding a battery packaging material and a lead wire.

[Explanation of symbols]

Short section between S lead wire and barrier layer H heat seal hot plate 1 battery 2 Battery body 3 cells (power storage unit) 4 Lead wire (electrode) 5 exterior body 6 Film for lead wire 7 recess 8 Side wall 9 Seal part 10 Laminated body (packaging material for batteries) 11 Base material layer 12 Barrier layer 12b Barrier layer substrate 13 Adhesive layer 13d dry laminate layer 13h Acid-modified polyolefin baking layer 13e Extruded layer of acid-modified polyolefin 14 Sealant layer Outer layer of S1 sealant layer Intermediate layer of S2 sealant layer Inner layer of S3 sealant layer 15 Nickel layer 16 Base material side dry laminate layer 20 Press forming department 21 male 22 female 23 cavities

Continued front page    (72) Inventor Kazuki Yamada             1-1-1, Ichigaya-Kagacho, Shinjuku-ku, Tokyo             Dai Nippon Printing Co., Ltd. (72) Inventor Masataka Okushita             1-1-1, Ichigaya-Kagacho, Shinjuku-ku, Tokyo             Dai Nippon Printing Co., Ltd. F-term (reference) 5H011 AA02 AA09 BB03 CC10 DD13

Claims (7)

[Claims] 1. A packaging material for forming an outer casing of a battery in which a battery main body is inserted and a peripheral portion is sealed by heat sealing is composed of at least a base material layer, an adhesive layer 1, a barrier layer, an adhesive layer 2 and a sealant layer. A packaging material for a battery, wherein the packaging material is a laminated body having at least a surface of a barrier layer made of nickel. 2. The battery packaging material according to claim 1, wherein the barrier layer is made of nickel foil. 3. The battery packaging material according to claim 1, wherein the barrier layer is made of nickel-plated aluminum foil. 4. The battery packaging material according to claim 1, wherein the barrier layer is made of nickel-plated copper foil. 5. The battery packaging material according to claim 1, wherein the adhesive layer 1 and the adhesive layer 2 are formed by a dry laminating method. 6. The battery packaging material according to claim 1, wherein at least the adhesive layer 2 is an acid-modified polyolefin coating and baking layer. 7. The battery packaging material according to claim 1, wherein at least the adhesive layer 2 is an extruded layer of an acid-modified polyolefin.