JP2020119710A - Power storage device, exterior member for power storage device, power storage device aggregate, electrically-driven automobile and manufacturing method of power storage device - Google Patents

Abstract

To provide a power storage device which can increase the reliability.SOLUTION: A power storage device 10 comprising an exterior member 20 having a barrier layer 36, and a power storage element 11 sealed in the exterior member is to be installed in an electrically-driven automobile 1. The exterior member 20 has a peripheral seal part 21 and a receiving part 16 for the power storage element 11. A depth direction of the receiving part 16 and X direction orthogonal to the depth direction are set in a front-back direction or right-left direction of the electrically-driven automobile 1. Y direction which is perpendicular to the depth direction of the receiving part 16 and X direction is set in a height direction of the electrically-driven automobile 1. The exterior member has a corrosion resistant coating on at least one surface of the barrier layer 36. According to analysis by time-of-flight secondary ion mass spectrometry about the corrosion resistant coating, the ratio Pof a peak intensity Poriginating from POto a peak intensity Poriginating from CePOfalls within a range of 80-120, or the ratio Pof a peak intensity Poriginating from POto the peak intensity Pfalls within a range of 90-150.SELECTED DRAWING: Figure 3

Description

The present invention relates to a power storage device mounted on an electric vehicle and a manufacturing method thereof. The present invention also relates to a power storage device exterior member used for a power storage device. The present invention also relates to an electric storage device assembly and an electric vehicle using the electric storage device.

2. Description of the Related Art In recent years, electric vehicles, in which a motor supplies at least a part of driving force, have attracted attention from the viewpoint of environmental measures and resource saving. The electric vehicle includes an electric vehicle (EV), a hybrid vehicle (HEV), a plug-in hybrid vehicle (PHEV), and the like. Electric vehicles use only a motor as a power source, and hybrid vehicles and plug-in hybrid vehicles use a motor and an engine as power sources.

A conventional power storage device mounted on an electric vehicle is disclosed in Patent Document 1. This electricity storage device is composed of a thin secondary battery that is rectangular in plan view and covers the battery element with an exterior member. In the battery element, a positive electrode plate and a negative electrode plate are arranged to face each other with a separator interposed therebetween, and an electrolyte is arranged between the positive electrode plate and the negative electrode plate. The exterior member encloses the battery element by heat-sealing the two laminated bodies having the metal foil with the heat-sealable resin layer. At this time, the terminals connected to the positive electrode plate and the negative electrode plate respectively project from the exterior member.

The power storage devices are stacked in the thickness direction and arranged in parallel in the short-side direction of a rectangle in plan view to form an assembled battery composed of a plurality of power storage devices. In addition, the assembled batteries are stacked in the thickness direction of the power storage device, and a composite assembled battery including a plurality of assembled batteries is installed under the floor of the electric vehicle.

Japanese Patent No. 3719235 (4th to 11th pages, FIG. 7)

However, according to the conventional power storage device, the weight of the upper power storage device is added to the lower power storage device because they are stacked in the height direction when mounted on a vehicle. As a result, the exterior member made of the laminated body may be deformed, and the exterior member may be damaged when the weight is increased due to vibration of the vehicle or the like. Therefore, there is a problem that the reliability of the power storage device and the electric vehicle is reduced.

An object of the present invention is to provide an electricity storage device, an electricity storage device assembly, and an electric vehicle that can improve reliability. It is another object of the present invention to provide an exterior member for an electricity storage device used for an electricity storage device that can improve reliability and a method for manufacturing the electricity storage device.

In order to achieve the above object, the present invention is to drive an electric vehicle by encapsulating a power storage element in an exterior member composed of a laminate including at least a base material layer, a barrier layer, and a heat-fusible resin layer in this order. In a power storage device mounted as a power source, the exterior member includes a peripheral edge seal portion, and a storage portion that is formed at a predetermined depth from an inner edge of the peripheral edge seal portion and that stores the power storage element. A second direction orthogonal to the depth direction of the electric storage unit and the first direction orthogonal to the depth direction of the storage unit and the first direction orthogonal to the depth direction of the electric storage unit. Direction is arranged in the height direction of the electric vehicle,
A surface of at least one side of the barrier layer is provided with a corrosion resistant film, and when the corrosion resistant film is analyzed using a time-of-flight secondary ion mass spectrometry method, it has a peak intensity P _{CePO 4} derived from CePO ₄ ⁻ . PO ₃ ^- the ratio P _{PO3 / CePO4} the peak intensity P _PO3 derived from, in the range of 80 to 120, or PO ₂ with respect to the peak intensity P _CePO4 ^- the ratio P _{PO2 / CePO4} from the peak intensity P _PO2, It is characterized by being in the range of 90 to 150.

Further, the present invention is characterized in that, in the electric storage device having the above-mentioned configuration, the length of the storage portion in the first direction is larger than the length in the second direction.

Further, the present invention is characterized in that, in the electric storage device having the above-mentioned configuration, the length of the storage portion in the first direction is 2 to 30 times the length in the second direction.

Further, the present invention is characterized in that, in the electric storage device having the above-mentioned configuration, the peripheral edge seal portion extending in the first direction is bent and overlapped on a peripheral wall of the storage portion.

Further, the present invention is characterized in that, in the electric storage device having the above-mentioned configuration, a flow direction of the exterior member is orthogonal to the first direction.

Further, according to the present invention, in the electric storage device having the above structure, the electric storage element has a first electrode terminal and a second electrode terminal, and the first electrode terminal and the second electrode terminal extend in the second direction. It is characterized by protruding from.

Further, the present invention is characterized in that, in the electric storage device having the above-mentioned configuration, the first electrode terminal and the second electrode terminal respectively project from the peripheral edge seal portions facing each other in the first direction.

Further, the present invention is characterized in that, in the electricity storage device having the above-mentioned configuration, the barrier layer is provided with the corrosion resistant coating on the surface of the heat-fusible resin layer side.

Further, the present invention is characterized in that, in the electricity storage device having the above structure, the corrosion resistant film and the heat-fusible resin layer are laminated via an adhesive layer.

Further, the present invention is characterized in that, in the electric storage device having the above structure, the resin forming the adhesive layer has a polyolefin skeleton.

Further, the present invention is characterized in that, in the electricity storage device having the above structure, the adhesive layer contains an acid-modified polyolefin.

Further, the present invention is characterized in that, in the electricity storage device having the above structure, the acid-modified polyolefin contained in the adhesive layer is maleic anhydride-modified polypropylene, and the heat-fusible resin layer contains polypropylene.

Further, the present invention is characterized in that, in the electricity storage device having the above structure, a peak derived from maleic anhydride is detected when the adhesive layer is analyzed by infrared spectroscopy.

The present invention also provides the electric storage device having the above structure, wherein the adhesive layer is a resin composition containing at least one selected from the group consisting of a compound having an isocyanate group, a compound having an oxazoline group, and a compound having an epoxy group. It is characterized by being a cured product.

In the electric storage device having the above structure according to the present invention, the adhesive layer includes a curing agent having at least one selected from the group consisting of an oxygen atom, a heterocycle, a C=N bond, and a C-O-C bond. It is characterized by being a cured product of a resin composition.

Further, the present invention is characterized in that, in the electricity storage device having the above-mentioned configuration, the adhesive layer contains at least one selected from the group consisting of urethane resin, ester resin, and epoxy resin.

Further, the present invention is characterized in that, in the electric storage device having the above-mentioned structure, the barrier layer is made of an aluminum foil.

Further, the present invention is characterized in that, in the electric storage device having the above structure, the resin forming the heat-fusible resin layer contains a polyolefin skeleton.

Further, the present invention provides a plurality of power storage devices having the above-mentioned configurations arranged in parallel in the depth direction of the storage section and stored in an outer container, and a plurality of the power storage devices arranged in an electric vehicle mounted on an electric vehicle. It is characterized in that the length in the installed direction is larger than the length in the second direction.

Further, an electric vehicle of the present invention includes the power storage device assembly having the above configuration, a drive motor supplied with power from the power storage device assembly, and wheels driven by the drive motor, and the power storage device assembly is a vehicle body. It is characterized in that it is arranged in one step in the height direction at the bottom.

Further, the present invention is, in an exterior member for an electricity storage device that encloses an electricity storage device of an electricity storage device mounted as a drive source in an electric vehicle, at least a base material layer, a barrier layer, and a heat fusible resin layer in this order. A laminated body including an opening formed on one surface to have a predetermined depth and accommodating the storage element, and a second packaging material protruding from a peripheral edge of the opening to an outer peripheral side. A flange portion that is heat-sealed, and a predetermined length of the storage portion in a first direction within a plane perpendicular to a depth direction of the storage portion is greater than a length in a second direction orthogonal to the first direction. Is also large, the flow direction of the laminate is orthogonal to the first direction,
A surface of at least one side of the barrier layer is provided with a corrosion resistant film, and when the corrosion resistant film is analyzed using a time-of-flight secondary ion mass spectrometry method, it has a peak intensity P _{CePO 4} derived from CePO ₄ ⁻ . PO ₃ ^- the ratio P _{PO3 / CePO4} the peak intensity P _PO3 derived from, in the range of 80 to 120, or PO ₂ with respect to the peak intensity P _CePO4 ^- the ratio P _{PO2 / CePO4} from the peak intensity P _PO2, It is characterized by being in the range of 90 to 150.

Further, the present invention is characterized in that, in the electricity storage device exterior member having the above-described configuration, the length of the storage portion in the first direction is 2 to 30 times the length in the second direction.

Further, the present invention provides a storage part provided by a laminated body including at least a base material layer, a barrier layer, and a heat-fusible resin layer in this order in a method of manufacturing an electricity storage device mounted on an electric vehicle as a drive source. A first orthogonal to the depth direction of the accommodating part and the depth direction of the accommodating part. The direction is arranged in the front-rear direction or the left-right direction of the electric vehicle, and the second direction orthogonal to the depth direction of the storage unit and the first direction is arranged in the height direction of the electric vehicle, and The length in the first direction is greater than the length in the second direction,
A surface of at least one side of the barrier layer is provided with a corrosion resistant film, and when the corrosion resistant film is analyzed using a time-of-flight secondary ion mass spectrometry method, it has a peak intensity P _{CePO 4} derived from CePO ₄ ⁻ . PO ₃ ^- the ratio P _{PO3 / CePO4} the peak intensity P _PO3 derived from, in the range of 80 to 120, or PO ₂ with respect to the peak intensity P _CePO4 ^- the ratio P _{PO2 / CePO4} from the peak intensity P _PO2, It is characterized by being in the range of 90 to 150.

Further, the present invention is characterized in that, in the method of manufacturing the electricity storage device having the above-described configuration, the length of the storage portion in the first direction is 2 to 30 times the length in the second direction.

Further, in the present invention, in the method for manufacturing an electricity storage device having the above-mentioned configuration, the step of packaging with the exterior member may include a peripheral edge seal portion for sealing the exterior member by heat fusion of the heat-fusible resin layer of the exterior member. It is characterized in that it is formed on the peripheral portion and the peripheral edge seal portion extending in the second direction is bent and overlapped on the peripheral wall of the storage portion.

Further, the present invention is characterized in that, in the method of manufacturing the electricity storage device having the above-mentioned configuration, the first direction is orthogonal to the flow direction of the exterior member.

According to the present invention, the power storage device is arranged in the depth direction of the housing portion of the exterior member and the first direction orthogonal to the depth direction in the front-rear direction or the left-right direction of the electric vehicle. A second direction orthogonal to the depth direction of the storage part and the first direction is arranged in the height direction of the electric vehicle. Accordingly, it is possible to install a plurality of power storage devices in an electric vehicle without stacking them and supply desired power. For this reason, it is possible to prevent damage to the exterior member due to the weight when the power storage devices are stacked.

In addition, when an anticorrosion coating disposed on the surface of the barrier layer of the exterior member is analyzed by time-of-flight secondary ion mass spectrometry, the peak intensity derived from CePO ₄ ⁻ is derived from PO ₃ ⁻ to P _{CePO 4} ^−. the ratio P _{PO3 / CePO4} peak intensity P _PO3 is in the range of 80 to 120, or PO ₂ to the peak intensity P _CePO4 ^- the ratio P _{PO2 / CePO4} the peak intensity P _PO2 derived is in the range of 90 to 150 is there. Therefore, an exterior member having excellent barrier layer adhesion can be obtained. Therefore, the reliability of the power storage device, the power storage device aggregate, and the electric vehicle can be improved.

Further, according to the exterior member for an electricity storage device of the present invention, it is formed of a laminated body in which the surface of the barrier layer is provided with a corrosion resistant film, and has a storage portion and a flange portion. Further, in the plane perpendicular to the depth direction of the storage portion, the length of the storage portion in the first direction is larger than the length in the second direction orthogonal to the first direction, and the flow direction of the stacked body is orthogonal to the first direction. To do. Accordingly, the flange portion is heat-sealed to form the peripheral edge seal portion, and when the peripheral edge seal portion extending in the first direction is bent, pinholes and cracks in the power storage device exterior member can be reduced.

In addition, when analyzed using time-of-flight secondary ion mass spectrometry for the corrosion barrier coating which arranged on the surface of the barrier layer, CePO ₄ ^- PO ₃ to the peak intensity P _CePO4 derived from ^- peak intensity derived from the P the ratio P _{PO3 / CePO4} of _PO3 is in the range of 80 to 120, or PO ₂ with respect to the peak intensity P _CePO4 ^- the ratio P _{PO2 / CePO4} the peak intensity P _PO2 derived is in the range of 90 to 150. Therefore, it is possible to obtain the exterior member for an electricity storage device, which has excellent adhesion to the barrier layer. Therefore, the yield of the electricity storage device can be improved and the reliability can be improved.

The side view which shows the electric vehicle of 1st Embodiment of this invention. The top view which shows the electric vehicle of 1st Embodiment of this invention. 1 is a perspective view showing a power storage device pack for an electric vehicle according to a first embodiment of the present invention. 1 is an exploded perspective view showing a power storage device of an electric vehicle according to a first embodiment of the present invention. A side sectional view showing an electric storage device of an electric vehicle according to a first embodiment of the present invention. Sectional drawing which shows the packaging material of the exterior member of the electrical storage device of the electric vehicle of 1st Embodiment of this invention. Sectional drawing which shows the other packaging material of the exterior member of the electrical storage device of the electric vehicle of 1st Embodiment of this invention. Sectional drawing which shows another packaging material of the exterior member of the electric storage device of the electric vehicle of 1st Embodiment of this invention. Sectional drawing which shows another packaging material of the exterior member of the electric storage device of the electric vehicle of 1st Embodiment of this invention. Sectional drawing which shows another packaging material of the exterior member of the electric storage device of the electric vehicle of 1st Embodiment of this invention. The disassembled perspective view which shows the electric storage device of the electric vehicle of 2nd Embodiment of this invention. A side sectional view showing an electricity storage device of an electric vehicle according to a second embodiment of the present invention. A side sectional view showing a state in which a power storage device of an electric vehicle according to a second embodiment of the present invention is covered with a protective cover. A side sectional view showing a state in which an electric storage device of an electric vehicle according to a second embodiment of the present invention is covered with another protective cover. The disassembled perspective view which shows the electric storage device of the electric vehicle of 3rd Embodiment of this invention. The top view which shows the electric vehicle of 4th Embodiment of this invention.

<First Embodiment>
Embodiments of the present invention will be described below with reference to the drawings. 1 and 2 show a side view and a top view of an electric vehicle 1 according to the first embodiment. The electric vehicle 1 includes a drive motor 3 as a power source for driving the wheels 2. An electric storage device pack 5 (electric storage device assembly) is installed below the floor of the vehicle body of the electric vehicle 1 as a drive source for supplying electric power to the drive motor 3.

FIG. 3 shows a perspective view of the electricity storage device pack 5. The power storage device pack 5 includes a plurality of power storage devices 10 arranged side by side and is covered with an outer container 6. The power storage device pack 5 may be configured by arranging a plurality of power storage device modules that package a plurality of power storage devices 10 in parallel.

Each power storage device 10 is provided with a positive electrode terminal 12 and a negative electrode terminal 13 (see FIG. 4) made of metal. The electrode terminals 12 and 13 are electrically connected in a predetermined order, and a pair of connection terminals (not shown) project from the outer container 6.

The outer container 6 is formed by a laminated body in which a heat-fusible resin layer, a metal foil, and a base material layer are laminated. The space between each power storage device 10 and the outer container 6 is filled with a filler (not shown), and the heat-fusible resin layer is heat-sealed to seal the outer container 6. The outer container 6 may be formed by injection molding.

4 and 5 show an exploded perspective view and a side sectional view of the electricity storage device 10. The electricity storage device 10 is composed of a secondary battery in which an electricity storage element 11 is enclosed in an exterior member 20. Examples of the electricity storage device 10 include a lithium-ion battery, a lithium-ion polymer battery, a lithium-ion all-solid-state battery, a lead storage battery, a nickel-hydrogen storage battery, a nickel-cadmium storage battery, a nickel-iron storage battery, a nickel-zinc storage battery, a silver-zinc oxide storage battery, a metal-air battery, and A valent cation battery or the like is used.

The electricity storage element 11 is formed by arranging a positive electrode plate and a negative electrode plate (neither shown) so as to face each other with an insulating separator (not shown) interposed therebetween. Electrode terminals 12 and 13 are connected to the positive electrode plate and the negative electrode plate, respectively. The electricity storage device 11 can be formed by winding a long separator, a positive electrode plate, and a negative electrode plate. The sheet-shaped positive electrode plate, the separator, the negative electrode plate, and the separator may be stacked in this order in a plurality of stages to form the electricity storage device 11. Alternatively, the electricity storage device 11 may be formed by folding and stacking a long separator, a positive electrode plate, and a negative electrode plate.

An electrolyte is arranged between the positive electrode plate and the negative electrode plate. In this embodiment, the electrolyte is made of an electrolytic solution and is filled inside the exterior member 20. A solid electrolyte or a gel electrolyte may be used as the electrolyte.

The exterior member 20 includes a packaging material 15 (first packaging material) and a packaging material 25 (second packaging material) which are formed of a laminated body having a heat-fusible resin layer 38 (see FIG. 6) on the inner surface.

FIG. 6 is a cross-sectional view showing the laminated structure of the packaging material 15. The packaging material 25 has the same laminated structure as the packaging material 15. The packaging material 15 and the packaging material 25 are composed of at least a laminate having a base material layer 34, a barrier layer 36, and a heat-fusible resin layer 38 in this order. The base material layer 34 becomes the outermost layer, and the heat-fusible resin layer 38 becomes the innermost layer. That is, the heat-fusible resin layers 38 located on the periphery of the power storage element 11 are heat-sealed to seal the power storage device 10.

A corrosion resistant coating 36a is provided on at least one surface of the barrier layer 36. The corrosion resistant coating 36a contains cerium. In the packaging material 15 shown in FIG. 6, a corrosion resistant coating 36a is provided on the surface of the barrier layer 36 on the side of the heat-fusible resin layer 38.

The packaging materials 15 and 25 may have other laminated configurations. For example, the packaging materials 15 and 25 shown in FIG. 7 are provided with the corrosion resistant coatings 36a and 36b on both surfaces of the barrier layer 36, respectively. At this time, as shown in FIG. 8, an adhesive layer 35 may be provided between the base material layer 34 and the barrier layer 36 as needed for the purpose of enhancing the adhesiveness. Further, as shown in FIG. 9, an adhesive layer 37 may be provided between the barrier layer 36 and the heat-fusible resin layer 38 as needed for the purpose of enhancing the adhesiveness.

Further, as shown in FIG. 10, a surface coating layer may be provided on the side opposite to the barrier layer 36 of the base material layer 34 as needed for the purpose of improving designability, electrolytic solution resistance, scratch resistance, moldability, and the like. 32 may be provided. At this time, the surface coating layer 32 becomes the outermost layer.

7 to 10, the corrosion resistant coating 36a may be omitted, and the corrosion resistant coating 36b may be provided only on the surface of the barrier layer 36 on the base material layer 34 side.

The thickness of the laminate forming the packaging materials 15 and 25 is not particularly limited, but is preferably 60 μm or more in consideration of strength, and 400 μm or less in consideration of weight reduction of the electricity storage device 10. The thickness of the packaging materials 15 and 25 is more preferably about 180 μm or less, and even more preferably about 150 μm or less. Thereby, it is possible to obtain the packaging materials 15 and 25 having excellent formability while reducing the thickness of the packaging materials 15 and 25 and increasing the energy density of the electricity storage device 10.

In the exterior material for an electricity storage device, the vertical direction (MD) and the horizontal direction (TD) can be normally discriminated in the manufacturing process based on the barrier layer 36, which will be described in detail later. For example, when the barrier layer 36 is made of aluminum foil, linear streaks called so-called rolling marks are formed on the surface of the aluminum foil. Since the rolling marks extend along the rolling direction (RD: Rolling Direction) of the aluminum foil, the rolling direction can be grasped by observing the surface of the aluminum foil.

In addition, in the manufacturing process of the laminated body, the MD of the laminated body and the RD of the aluminum foil usually match. Therefore, the MD of the laminated body can be specified by observing the surface of the aluminum foil of the laminated body and specifying the rolling direction (RD). Since the TD of the laminated body is perpendicular to the MD, the TD of the laminated body can also be specified.

(Base material layer 34)
The base material layer 34 of the packaging materials 15 and 25 is a layer located on the outermost layer side. The material forming the base material layer 34 is not particularly limited as long as it has an insulating property. As a material for forming the base material layer 34, for example, a resin film such as a polyester resin, a polyamide resin, an epoxy resin, an acrylic resin, a fluororesin, a polyurethane resin, a silicon resin, a phenol resin, a polycarbonate resin, or a mixture or copolymer thereof. Are listed.

Among these, polyester resin and polyamide resin are preferable, and biaxially stretched polyester resin and biaxially stretched polyamide resin are more preferable. Specific examples of the polyester resin include polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, and copolyester. Specific examples of the polyamide resin include nylon 6, nylon 66, a copolymer of nylon 6 and nylon 66, nylon 6,10, and polyamide MXD6 (polymethaxylylene adipamide).

The base material layer 34 may be formed of one layer of resin film, but may be formed of two or more layers of resin film in order to improve pinhole resistance and insulation. Specific examples include a multilayer structure in which a polyester film and a nylon film are laminated, a multilayer structure in which a plurality of nylon films are laminated, a multilayer structure in which a plurality of polyester films are laminated, and the like.

When the base material layer 34 has a multilayer structure, a laminate of a biaxially oriented nylon film and a biaxially oriented polyester film, a laminate of a plurality of biaxially oriented nylon films, and a laminate of a plurality of biaxially oriented polyester films. The body is preferred.

For example, when the base material layer 34 is formed from two resin films, a configuration in which a polyester resin and a polyester resin are laminated, a configuration in which a polyamide resin and a polyamide resin are laminated, or a configuration in which a polyester resin and a polyamide resin are laminated. Is preferred. It is more preferable to use a structure in which polyethylene terephthalate and polyethylene terephthalate are laminated, a structure in which nylon and nylon are laminated, or a structure in which polyethylene terephthalate and nylon are laminated.

In addition, since the polyester resin does not easily discolor when the electrolytic solution adheres to the surface, for example, in the laminated structure, it is preferable to laminate the base material layer 34 so that the polyester resin is located at the outermost layer. When the base material layer 34 has a multilayer structure, the thickness of each layer is preferably about 2 to 25 μm.

When the base material layer 34 is formed of a multilayer resin film, two or more resin films may be laminated via an adhesive component such as an adhesive or an adhesive resin. The types and amounts of the adhesive components used for lamination are the same as those of the adhesive layer 35 described later. The method for laminating two or more resin films is not particularly limited, and a known method can be adopted. For example, a dry laminating method, a sandwich laminating method, a co-extrusion laminating method and the like can be mentioned, and a dry laminating method is preferable. When laminating by a dry laminating method, it is preferable to use a urethane adhesive as the adhesive layer. At this time, the thickness of the adhesive layer is, for example, about 2 to 5 μm.

From the viewpoint of enhancing the moldability of the packaging materials 15 and 25, it is preferable that a lubricant is attached to the surface of the base material layer 34. The lubricant is not particularly limited, but an amide lubricant is preferable. Specific examples of the amide-based lubricant are the same as those exemplified for the heat-fusible resin layer 38 described later.

When the lubricant is present on the surface of the base material layer 34, its amount is not particularly limited, but it is preferably about 3 mg/m ² or more in an environment of a temperature of 24° C. and a relative humidity of 60%. The amount of lubricant present is more preferably about 4 to 15 mg/m ² , and even more preferably about 5 to 14 mg/m ² .

A lubricant may be included in the base material layer 34. The lubricant present on the surface of the base material layer 34 may be one in which the lubricant contained in the resin forming the base material layer 34 is exuded, and the lubricant is applied to the surface of the base material layer 34. May be.

The thickness of the base material layer 34 is not particularly limited as long as the function as the base material layer 34 is exhibited, but is, for example, about 3 to 50 μm, preferably about 10 to 35 μm.

(Adhesive layer 35)
The adhesive layer 35 is a layer provided between the base material layer 34 and the barrier layer 36 as needed in order to firmly bond them. The adhesive layer 35 is formed of an adhesive that can bond the base layer 34 and the barrier layer 36. The adhesive used for forming the adhesive layer 35 may be a two-component curing type adhesive or a one-component curing type adhesive. Further, the adhesive may be any of a chemical reaction type, a solvent volatilization type, a heat melting type, a hot pressing type and the like.

As an adhesive component that can be used to form the adhesive layer 35, a polyester resin, a polyether resin, a polyurethane resin, an epoxy resin, a phenol resin resin, a polycarbonate resin, a polyamide resin, a polyolefin resin, polyvinyl acetate. Examples thereof include resin, cellulose adhesive, (meth)acrylic resin, polyimide resin, amino resin, silicone resin, rubber and the like.

Examples of the polyester resin include polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polyethylene isophthalate, and copolyester.

Examples of the polyamide resin include nylon 6, nylon 66, nylon 12, and copolyamide. Examples of the polyolefin resin include polyolefin, carboxylic acid-modified polyolefin, and metal-modified polyolefin.

Examples of the amino resin include urea resin and melamine resin. Examples of the rubber include chloroprene rubber, nitrile rubber, styrene-butadiene rubber and the like.

These adhesive components may be used alone or in combination of two or more. In addition, the resin serving as the adhesive component may be used in combination with an appropriate curing agent to enhance the adhesive strength. The curing agent is appropriately selected from polyisocyanates, polyfunctional epoxy resins, oxazoline group-containing polymers, polyamine resins, acid anhydrides, etc. depending on the functional groups of the adhesive component.

Preferred examples of these adhesive components and curing agents include polyurethane-based adhesives composed of various polyols (adhesive components having a hydroxyl group) and polyisocyanate. More preferred is a two-component curing type polyurethane adhesive containing a polyol such as a polyester polyol, a polyether polyol and an acrylic polyol as a main component and an aromatic or aliphatic polyisocyanate as a curing agent.

The adhesive layer 35 may contain a coloring agent such as a pigment. The thickness of the adhesive layer 35 is not particularly limited as long as it functions as an adhesive layer, but is, for example, about 1 to 10 μm, preferably about 2 to 5 μm.

(Barrier layer 36)
The barrier layer 36 is a layer having a function of preventing the entry of water vapor, oxygen, light and the like into the inside of the electricity storage device 10 in addition to improving the strength. The barrier layer 36 is preferably a metal layer, that is, a layer formed of a metal. Specific examples of the metal forming the barrier layer 36 include aluminum (including an aluminum alloy), stainless steel, titanium, and the like, and aluminum is preferable.

The barrier layer 36 can be formed of, for example, a metal foil, a metal vapor deposition film, a film provided with these vapor deposition films, or the like. The barrier layer 36 is preferably formed of a metal foil, more preferably an aluminum foil.

The barrier layer 36 is formed of a soft aluminum foil such as annealed aluminum (JIS H4160:1994 A8021H-O, JIS H4160:1994 A8079H-O, JIS H4000:2014 A8021P-O, JIS H4000:2014 A8079P-O). More preferably. As a result, it is possible to prevent wrinkles and pinholes from being generated in the barrier layer 36 when the packaging materials 15 and 25 are manufactured.

The thickness of the barrier layer 36 is not particularly limited as long as it functions as a barrier layer against water vapor and the like, but from the viewpoint of reducing the thickness of the packaging materials 15 and 25, it is preferably about 100 μm or less, more preferably about 10 to 100 μm, and further preferably. Is about 10 to 80 μm.

(Corrosion resistant films 36a, 36b)
The packaging materials 15 and 25 have a corrosion-resistant coating on the surface of at least one side of the barrier layer 36. The corrosion resistant coating 36a may be provided only on the surface of the barrier layer 36 on the side of the heat-fusible resin layer 38. The corrosion resistant coating 36b may be provided only on the surface of the barrier layer 36 on the base material layer 34 side. Both surfaces of the barrier layer 36 may be provided with corrosion resistant coatings 36a and 36b, respectively.

When water enters the electricity storage device 10, the water may react with the electrolyte or the like to generate an acidic substance. For example, when the electricity storage device 10 is a lithium-ion battery or the like, the electrolytic solution contains a fluorine compound (LiPF ₆ , LiBF _4, etc.) as an electrolyte. At this time, when water enters the electricity storage device 10, the fluorine compound reacts with water to generate hydrogen fluoride.

When an acid contacts the barrier layer 36 formed of a metal foil or the like, it is easily corroded. Therefore, the corrosion resistance coating 36a can be formed on the surface of the barrier layer 36 by the chemical conversion treatment, and the corrosion resistance of the packaging materials 15 and 25 can be improved.

Further, since the corrosion resistant coating 36b is provided, the adhesion between the corrosion resistant coating 36b on the surface of the barrier layer 36 and the base material layer 34 or the adhesive layer 35 can be enhanced. Accordingly, delamination of the base material layer 34 and the barrier layer 36 when exposed to high temperature and high humidity conditions can be prevented.

As a chemical conversion treatment for forming the corrosion resistant coatings 36a and 36b, there are known methods such as a chromate treatment using a chromium compound such as chromium oxide and a phosphoric acid treatment using a phosphoric acid compound.

A conventional barrier layer provided with a corrosion resistant coating may have insufficient adhesion with the layer adjacent to the side provided with the corrosion resistant coating (that is, the adhesion at the interface between the corrosion resistant coating and the layer in contact with it). is there. More specifically, the adhesion may be insufficient due to the electrolytic solution adhering to the packaging materials 15 and 25.

Therefore, the corrosion barrier coating 36a, for 36b, when analyzed using time-of-flight secondary ion mass spectrometry, CePO ₄ ^- ratio of the peak intensity P _PO3 derived from ^- PO ₃ to the peak intensity P _CePO4 derived from the P _{PO3 / CePO4,} in the range of 80 to 120, or, PO ₂ to the peak intensity P _CePO4 ^- the ratio P _{PO2 / CePO4} the peak intensity P _PO2 derived from, and within the range of 90 to 150.

As a result, even when the electrolytic solution adheres to the packaging materials 15 and 25, it is possible to prevent the adhesion between the barrier layer 36 and the layers adjacent to the side where the corrosion resistant coatings 36a and 36b are provided from being deteriorated. That is, by _{setting the} ratio P _{PO3 /CePO4} within the range of 80 to 120 or the ratio P _PO2/CePO4 within the range of ₉₀ to 150, the layer adjacent to the side on which the barrier layer 36 and the corrosion resistant coatings 36a, 36b are provided. It is possible to obtain the packaging materials 15 and 25 having excellent adhesion with.

When both sides of the barrier layer 36 are provided with the corrosion resistant coatings 36a and 36b, the ratio P _{PO3 /CePO4} or the ratio P _{PO2/CePO4 of the} peak strengths in the corrosion resistant coating on either surface is within the above range. I wish I had it. However, it is more preferable that the ratio P _{PO3 /CePO 4} or the ratio P _{PO2/CePO 4} of the peak intensities of both the corrosion resistant coatings 36 a and 36 b is within the above range.

In particular, the corrosion-resistant coating 36a located on the heat-fusible resin layer 38 side of the barrier layer 36 and the layer (the adhesive layer 37 or the heat-fusible resin layer 38) adjacent to the corrosion-resistant coating 36a are formed by the permeation of the electrolytic solution. Adhesion tends to decrease. Therefore, it is preferable that at least the surface of the barrier layer 36 on the heat-fusible resin layer 38 side is provided with the corrosion-resistant coating 36a. And, it is preferable that the ratio P _PO2/CePO4 or the ratio P _{PO3/CePO4 of the} peak intensity of the corrosion resistant coating 36a is within the above range. Regarding these points, the same applies to the ratio of each peak intensity shown below.

The peak intensity ratio P _{PO3 /CePO 4} may be in the range of 80 to 120, but from the viewpoint of further improving the adhesion of the barrier layer 36 provided with the corrosion resistant coating, the lower limit is preferably set to about 85, and more preferably set to about 92. .. The upper limit of the ratio P _{PO3 /CePO 4} is preferably about 110, more preferably about 105, and even more preferably about 98. That is, the preferable range of the ratio P _{PO3 /CePO4} is about 80 to 110, 80 to 105, 80 to 98, 85 to 120, 85 to 110, 85 to 105, 85 to 98, 92 to 120. About 92-110, about 92-105, about 92-98.

Further, the peak intensity ratio P _PO2/CePO4 may be in the range of ₉₀ to 150, but from the viewpoint of further improving the adhesion of the barrier layer 36 provided with the corrosion resistant film, the lower limit is preferably about 110 and the upper limit is set to about It is preferably 130. More preferably, the upper limit of the ratio P _PO2/CePO4 is about 116. That is, the preferable range of the ratio P _PO2/CePO4 is about 90 to 130, about 90 to 116, about 110 to 150, about 110 to 130, and about 110 to 116.

The analysis using the time-of-flight secondary ion mass spectrometry can be carried out under the following measurement conditions using a time-of-flight secondary ion mass spectrometer.

Primary ion: Double-charged bismuth cluster ion (Bi ₃ ⁺⁺ ).
Primary ion acceleration voltage: 30 kV
Mass range (m/z): 0 to 1500
Measuring range: 100 μm×100 μm
Number of scans: 16 scan/cycle
Number of pixels (1 side): 256 pixels
Etching ions: Ar gas cluster ion beam (Ar-GCIB)
Etching ion acceleration voltage: 5.0 kV

Further, the fact that the corrosion-resistant coatings 36a and 36b contain cerium can be confirmed by using X-ray photoelectron spectroscopy. Specifically, the layers laminated on the barrier layer 36 (the adhesive layer 35, the heat-fusible resin layer 38, the adhesive layer 37, etc.) are physically peeled off. Next, the barrier layer 36 is placed in an electric furnace to remove the organic component existing on the surface of the barrier layer 36 at about 300° C. for about 30 minutes. After that, the presence of cerium is confirmed using X-ray photoelectron spectroscopy on the surface of the barrier layer 36.

The corrosion resistant films 36a and 36b can be formed by subjecting the surface of the barrier layer 36 to chemical conversion treatment with a treatment liquid containing a cerium compound such as cerium oxide. For example, a treatment liquid in which a cerium compound such as cerium oxide is dispersed in phosphoric acid and/or its salt is dissolved in a solvent is applied to the surface of the barrier layer 36, and a baking treatment is performed. As a result, the corrosion resistant coatings 36a and 36b are formed on the surface of the barrier layer 36 by the chemical conversion treatment.

Examples of the method of applying the treatment liquid containing the cerium compound to the surface of the barrier layer 36 include a bar coating method, a roll coating method, a gravure coating method, and a dipping method.

The ratio P _{PO3 /CePO4} or the ratio P _PO2/CePO4 of the peak strengths of the corrosion-resistant coatings 36a, 36b is _adjusted by, for example, the composition of the treatment liquid forming the corrosion-resistant coatings 36a, 36b, the conditions of baking treatment (temperature, time, etc.) be able to.

The ratio of the cerium compound to the phosphoric acid and/or its salt in the treatment liquid containing the cerium compound is not particularly limited, but the ratio P _{PO3 /CePO 4} or the ratio P _{PO2/CePO 4} should be set within the above ranges, respectively. Is adjusted to. For example, with respect to 100 parts by mass of the cerium compound, the phosphoric acid and/or its salt is preferably about 12 to 28 parts by mass, more preferably about 15 to 25 parts by mass. As the phosphoric acid or its salt contained in the treatment liquid, for example, condensed phosphoric acid or its salt can be used.

The treatment liquid containing the cerium compound may further contain an anionic polymer and a crosslinking agent for crosslinking the anionic polymer. Examples of the anionic polymer include poly(meth)acrylic acid or a salt thereof, a copolymer containing (meth)acrylic acid or a salt as a main component, and the like. Examples of the cross-linking agent include compounds having a functional group of any one of an isocyanate group, a glycidyl group, a carboxyl group and an oxazoline group, a silane coupling agent, and the like. The anionic polymer and the cross-linking agent may each be one kind or two or more kinds.

Further, from the viewpoint of enhancing the adhesion of the barrier layer 36 while exhibiting excellent corrosion resistance, it is preferable that the treatment liquid containing the cerium compound contains an aminated phenol polymer. In the treatment liquid containing the cerium compound, about 100 to 400 parts by mass of the aminated phenol polymer is preferable, and about 200 to 300 parts by mass is more preferable, relative to 100 parts by mass of the cerium compound.

The weight average molecular weight of the aminated phenol polymer is preferably about 5,000 to 20,000. The weight average molecular weight of the aminated phenol polymer is a value measured by gel permeation chromatography (GPC) under the condition that polystyrene is used as a standard sample.

The solvent of the treatment liquid containing the cerium compound is not particularly limited as long as it can evaporate the components contained in the treatment liquid and is heated thereafter, but water is preferable.

The solid content concentration of the treatment liquid containing the cerium compound is not particularly limited, but can be, for example, about 8 to 30% by mass. The solid content concentration of the treatment liquid is more preferably about 9.0 to 10.0 parts by mass, and even more preferably about 9.1 to 9.5 parts by mass, relative to 100 parts by mass of the solvent (water or the like). As a result, the ratio P _{PO3 /CePO 4} or the ratio P _PO2/CePO4 of the peak intensity can be set within the above predetermined ranges, and the adhesion of the barrier layer 36 can be enhanced while exhibiting excellent corrosion resistance.

The surface temperature of the barrier layer 36 during the baking treatment is preferably about 170 to 250°C, more preferably about 180 to 230°C, still more preferably about 190 to 220°C. The heating time of the barrier layer 36 during the baking treatment is preferably about 2 to 10 seconds, more preferably about 3 to 6 seconds. By adopting such a temperature and heating time, the solvent can be appropriately evaporated and the corrosion resistant coatings 36a and 36b can be suitably formed. Thereby, the ratio P _{PO3 /CrPO4} or the ratio P _PO2/CrPO4 of the peak intensity can be set within the predetermined ranges, respectively, and the long-term adhesion of the barrier layer 36 can be enhanced while exhibiting excellent corrosion resistance.

Further, from the viewpoint of more efficiently performing the chemical conversion treatment on the surface of the barrier layer 36, before providing the corrosion-resistant coatings 36a and 36b on the surface of the barrier layer 36, an alkali dipping method, an electrolytic cleaning method, an acid cleaning method, an electrolytic acid Degreasing treatment is preferably performed by a known treatment method such as a washing method or an acid activation method.

The thickness of the corrosion resistant coatings 36a and 36b is not particularly limited, but is preferably about 1 nm to 10 μm from the viewpoint of enhancing the adhesion of the barrier layer 36 while exhibiting excellent corrosion resistance. The thickness of the corrosion resistant coatings 36a and 36b is more preferably about 1 to 100 nm, and even more preferably about 1 to 50 nm. The thickness of the corrosion resistant coatings 36a and 36b can be measured by observation with a transmission electron microscope. Alternatively, the thickness of the corrosion resistant coatings 36a and 36b can be measured by a combination of observation with a transmission electron microscope and energy dispersive X-ray spectroscopy or electron beam energy loss spectroscopy.

From the same viewpoint, the amount of the corrosion resistant coatings 36a and 36b per 1 m ² of the surface of the barrier layer 36 is preferably about 2 to 100 mg, more preferably about 2 to 70 mg, even more preferably about 2 to 40 mg.

(The heat-fusible resin layer 38)
The heat-fusible resin layer 38 corresponds to the innermost layer of the packaging materials 15 and 25, and is a layer that thermally fuses the heat-fusible resin layers 38 to each other to seal the power storage device 10.

The resin component used in the heat-fusible resin layer 38 is not particularly limited as long as it can be heat-bonded, but a polyolefin resin can be used. Examples of the polyolefin resin include polyolefin, cyclic polyolefin, acid-modified polyolefin, and acid-modified cyclic polyolefin. That is, the resin constituting the heat-fusible resin layer 38 may not contain the polyolefin skeleton, but it is preferable that the resin has the polyolefin skeleton.

The fact that the resin constituting the heat-fusible resin layer 38 contains a polyolefin skeleton can be analyzed by, for example, infrared spectroscopy, gas chromatography mass spectrometry, or the like. The analysis method is not limited to these. For example, when measuring the infrared spectroscopy by maleic anhydride-modified polyolefin, a peak derived from maleic acid is detected in the vicinity of the wave number of 1760 cm ^-1 and near the wave number 1780 cm ^-1. However, if the degree of acid modification is low, the peak may be too small to be detected. In that case, it can be analyzed by nuclear magnetic resonance spectroscopy.

Specific examples of the polyolefin include polyethylene, polypropylene, and an ethylene-butene-propylene terpolymer. Examples of polyethylene include low-density polyethylene, medium-density polyethylene, high-density polyethylene, and linear low-density polyethylene. Examples of polypropylene include homopolypropylene, block copolymers of polypropylene (for example, block copolymers of propylene and ethylene), random copolymers of polypropylene (for example, random copolymers of propylene and ethylene) and the like. Among these polyolefins, polyethylene and polypropylene are preferable.

Cyclic polyolefins are copolymers of olefins and cyclic monomers. Examples of the olefin which is a constituent monomer of the cyclic polyolefin include ethylene, propylene, 4-methyl-1-pentene, butadiene and isoprene. Examples of the cyclic monomer which is a constituent monomer of the cyclic polyolefin include cyclic alkenes and cyclic dienes. Examples of cyclic alkenes include norbornene. Examples of the cyclic diene include cyclopentadiene, dicyclopentadiene, cyclohexadiene and norbornadiene. Among these cyclic monomers, cyclic alkenes are preferable, and norbornene is more preferable.

The acid-modified polyolefin is a polymer modified by block-copolymerizing or graft-copolymerizing a polyolefin with an acid component such as carboxylic acid. Examples of the acid component used for modification include carboxylic acids such as maleic acid, acrylic acid, itaconic acid, crotonic acid, maleic anhydride, and itaconic anhydride, or anhydrides thereof.

The acid-modified cyclic polyolefin is a polymer obtained by copolymerizing a part of the monomers constituting the cyclic polyolefin by substituting α,β-unsaturated carboxylic acid or its anhydride. Alternatively, the acid-modified cyclic polyolefin is a polymer obtained by block-polymerizing or graft-polymerizing an α,β-unsaturated carboxylic acid or an anhydride thereof with respect to the cyclic polyolefin. The cyclic polyolefin modified with carboxylic acid is the same as above. The carboxylic acid used for modification is the same as that used for modification of the acid-modified polyolefin.

Of the above resins, polyolefins such as polypropylene and carboxylic acid-modified polyolefins are particularly preferable as the resin constituting the heat-fusible resin layer 38. More preferred are polypropylene and acid-modified polypropylene.

The heat-fusible resin layer 38 may be formed of one type of resin component alone, or may be formed of a blend polymer in which two or more types of resin components are combined. Further, the heat-fusible resin layer 38 may be formed of only one layer, but may be formed of two or more layers of the same or different resin components.

Further, it is preferable that a lubricant is attached to the surface of the heat-fusible resin layer 38. Thereby, the moldability of the packaging material 15 can be improved. The lubricant is not particularly limited, but an amide lubricant is preferable. Examples of the amide lubricant include saturated fatty acid amide, unsaturated fatty acid amide, substituted amide, methylol amide, saturated fatty acid bisamide, unsaturated fatty acid bisamide, fatty acid ester amide, aromatic bisamide and the like. The lubricant may be used alone or in combination of two or more.

Specific examples of the saturated fatty acid amide include lauric acid amide, palmitic acid amide, stearic acid amide, behenic acid amide, and hydroxystearic acid amide. Specific examples of the unsaturated fatty acid amide include oleic acid amide and erucic acid amide.

Specific examples of the substituted amide include N-oleylpalmitic acid amide, N-stearyl stearic acid amide, N-stearyl oleic acid amide, N-oleyl stearic acid amide, and N-stearyl erucic acid amide. Specific examples of methylol amide include methylol stearic acid amide.

Specific examples of the saturated fatty acid bisamide include methylenebisstearic acid amide, ethylenebiscapric acid amide, ethylenebislauric acid amide, ethylenebisstearic acid amide, ethylenebishydroxystearic acid amide, ethylenebisbehenic acid amide, and hexamethylenebisstearic acid. Examples thereof include amide, hexamethylene bisbehenic acid amide, hexamethylene hydroxystearic acid amide, N,N′-distearyl adipic acid amide, and N,N′-distearyl sebacic acid amide.

Specific examples of the unsaturated fatty acid bisamide include ethylenebisoleic acid amide, ethylenebiserucic acid amide, hexamethylenebisoleic acid amide, N,N′-dioleyl adipate amide, N,N′-dioleyl sebacic acid amide, and the like. Is mentioned.

Specific examples of the fatty acid ester amide include stearoamide ethyl stearate and the like. Specific examples of the aromatic bisamide include m-xylylenebisstearic acid amide, m-xylylenebishydroxystearic acid amide, N,N'-distearylisophthalic acid amide and the like.

The amount of the lubricant present on the surface of the heat-fusible resin layer 38 is not particularly limited, but is preferably about 3 mg/m ² or more in an environment of a temperature of 24° C. and a relative humidity of 60%. Abundance of lubricant temperature 24 ° C., at a relative humidity of 60% for more preferable to be about 4~15mg / m ^2, further preferably of about 5~14mg / m ^2.

Further, the lubricant may be contained in the heat-fusible resin layer 38. The lubricant present on the surface of the heat-fusible resin layer 38 may be applied, or the lubricant contained in the resin forming the heat-fusible resin layer 38 may be exuded.

The thickness of the heat-fusible resin layer 38 is not particularly limited as long as it exhibits the function as the heat-fusible resin layer, but is preferably about 60 μm or less, more preferably about 15 to 60 μm, further preferably about 15 to 40 μm. Can be mentioned.

(Adhesive layer 37)
The adhesive layer 37 is a layer that is provided between the barrier layer 36 and the heat-fusible resin layer 38 as needed in order to enhance the adhesiveness between them. The adhesive layer 37 may be composed of a single layer or may be composed of the same or different plural layers.

Generally, from the viewpoint of enhancing the adhesiveness between the barrier layer 36 and the heat-fusible resin layer 38, it is preferable to have the adhesive layer 37 between them. However, when the surface of the barrier layer 36 on the side of the heat-fusible resin layer 38 is provided with the corrosion-resistant coating 36a, there is a problem that the adhesiveness between the corrosion-resistant coating 36a and the adhesive layer 37 is likely to decrease.

On the other hand, in the present embodiment, the corrosion-resistant coating 36a has the above-mentioned specific peak intensity ratio P _{PO3 /CePO 4} or ratio P _{PO2/CePO 4} , and is therefore excellent in adhesion. Therefore, the adhesion between the corrosion resistant coating 36a and the adhesive layer 37 is also effectively improved. That is, in the packaging materials 15 and 25 in which the corrosion resistant coating 36 a on the surface of the barrier layer 36 and the heat-fusible resin layer 38 are laminated via the adhesive layer 37, the effect of excellent adhesion of the barrier layer 36 is exerted.

The adhesive layer 37 is formed of a resin capable of adhering the barrier layer 36 (further, the corrosion resistant film 36a) and the heat-fusible resin layer 38. As the resin used for forming the adhesive layer 37, the adhesive exemplified by the adhesive layer 35 or the polyolefin resin exemplified by the heat-fusible resin layer 38 can be used.

Examples of the polyolefin-based resin include polyolefin, cyclic polyolefin, carboxylic acid-modified polyolefin, carboxylic acid-modified cyclic polyolefin, and the like. That is, the resin forming the adhesive layer 37 preferably contains a polyolefin skeleton. From the viewpoint of excellent adhesion between the barrier layer 36 and the heat-fusible resin layer 38, polyolefin and carboxylic acid-modified polyolefin are preferable, and carboxylic acid-modified polypropylene is particularly preferable.

The fact that the resin forming the adhesive layer 37 contains a polyolefin skeleton can be analyzed by, for example, infrared spectroscopy, gas chromatography mass spectrometry, or the like. The analysis method is not limited to these. For example, when measuring the infrared spectroscopy by maleic anhydride-modified polyolefin, a peak derived from maleic acid is detected in the vicinity of the wave number of 1760 cm ^-1 and near the wave number 1780 cm ^-1. However, if the degree of acid modification is low, the peak may be too small to be detected. In that case, it can be analyzed by nuclear magnetic resonance spectroscopy.

Further, from the viewpoint of forming the packaging materials 15 and 25 that are thin and have excellent shape stability after molding, the adhesive layer 37 is a cured product of a resin composition containing a main agent composed of an acid-modified polyolefin and a curing agent. May be. As the acid-modified polyolefin, carboxylic acid-modified polyolefin and carboxylic acid-modified cyclic polyolefin are preferable.

The curing agent is not particularly limited as long as it cures the acid-modified polyolefin. Examples of the curing agent include epoxy curing agents, polyfunctional isocyanate curing agents, carbodiimide curing agents, oxazoline curing agents, and the like.

The epoxy curing agent is not particularly limited as long as it is a compound having at least one epoxy group. Specific examples of the epoxy-based curing agent include epoxy resins such as bisphenol A diglycidyl ether, modified bisphenol A diglycidyl ether, novolac glycidyl ether, glycerin polyglycidyl ether, and polyglycerin polyglycidyl ether.

The polyfunctional isocyanate curing agent is not particularly limited as long as it is a compound having two or more isocyanate groups. Specific examples of the polyfunctional isocyanate-based curing agent include isophorone diisocyanate (IPDI), hexamethylene diisocyanate (HDI), tolylene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), those obtained by polymerizing or nurate, and mixtures thereof. And copolymers with other polymers.

The carbodiimide curing agent is not particularly limited as long as it is a compound having at least one carbodiimide group (-N=C=N-). As a specific example of the carbodiimide-based curing agent, a polycarbodiimide compound having at least two carbodiimide groups is preferable.

The oxazoline-based curing agent is not particularly limited as long as it is a compound having an oxazoline skeleton (oxazoline group). Examples of the compound having an oxazoline group include those having a polystyrene main chain and those having an acrylic main chain. Specifically, Epocros (registered trademark) series manufactured by Nippon Shokubai Co., Ltd. can be used.

From the viewpoint of enhancing the adhesiveness between the barrier layer 36 and the heat-fusible resin layer 38 by the adhesive layer 37, the curing agent may be composed of two or more kinds of compounds.

The content of the curing agent in the resin composition forming the adhesive layer 37 is preferably in the range of about 0.1 to 50% by mass. Further, the content of the curing agent is more preferably in the range of about 0.1 to 30% by mass, and further preferably in the range of about 0.1 to 10% by mass.

That is, the adhesive layer 37 is a cured product of a resin composition containing a main agent composed of acid-modified polyolefin and a curing agent, and the curing agent is composed of a compound having an isocyanate group, a compound having an oxazoline group, and a compound having an epoxy group. It is preferable to include at least one selected from the group. Furthermore, it is more preferable that the curing agent contains at least one selected from the group consisting of a compound having an isocyanate group and a compound having an epoxy group.

In some cases, a compound having an isocyanate group, a compound having an oxazoline group, and an unreacted curing agent such as an epoxy resin remain in the adhesive layer 37. The presence of the unreacted substance of the curing agent can be confirmed by methods such as infrared spectroscopy, Raman spectroscopy, time-of-flight secondary ion mass spectrometry (TOF-SIMS), and the like.

The adhesive layer 37 may be formed of a resin containing at least one selected from the group consisting of urethane resin, ester resin and epoxy resin. The adhesive layer 37 is more preferably a cured product of a resin composition containing at least one of these resins and an acid-modified polyolefin. Further, it is more preferable that the adhesive layer 37 contains urethane resin and epoxy resin.

As the ester resin, for example, an amide ester resin is preferable. The amide ester resin is generally produced by the reaction of a carboxyl group and an oxazoline group.

Further, from the viewpoint of further improving the adhesion between the corrosion resistant coating 36a and the adhesive layer 37, the adhesive layer 37 is at least selected from the group consisting of oxygen atoms, heterocycles, C═N bonds, and C—O—C bonds. It is preferably a cured product of a resin composition containing one type of curing agent.

The fact that the adhesive layer 37 is a cured product of a resin composition containing these curing agents means that gas chromatograph mass spectrometry (GCMS), infrared spectroscopy (IR), time-of-flight secondary ion mass spectrometry (TOF-SIMS). ), X-ray photoelectron spectroscopy (XPS) and the like.

Examples of the curing agent having a heterocycle include a curing agent having an oxazoline group and a curing agent having an epoxy group. Examples of the curing agent having a C=N bond include a curing agent having an oxazoline group and a curing agent having an isocyanate group. Examples of the curing agent having a C—O—C bond include a curing agent having an oxazoline group, a curing agent having an epoxy group, and a urethane resin.

The curing agent having an oxazoline group is not particularly limited as long as it is a compound having an oxazoline skeleton. Examples of the compound having an oxazoline group include those having a polystyrene main chain and those having an acrylic main chain. Specifically, the above-mentioned EPOCROS series or the like can be used.

The proportion of the compound having an oxazoline group in the adhesive layer 37 is preferably in the range of 0.1 to 50% by mass, and in the range of 0.5 to 40% by mass in the resin composition constituting the adhesive layer 37. Is more preferable. As a result, the adhesion between the corrosion resistant coating 36a and the adhesive layer 37 can be effectively enhanced.

The curing agent having an isocyanate group is not particularly limited, but a polyfunctional isocyanate compound is preferable from the viewpoint of effectively enhancing the adhesion between the corrosion resistant coating 36a and the adhesive layer 37. The polyfunctional isocyanate compound is not particularly limited as long as it is a compound having two or more isocyanate groups. Specific examples of the polyfunctional isocyanate-based curing agent include those exemplified above for the adhesive layer 35.

The content of the compound having an isocyanate group in the adhesive layer 37 is preferably in the range of 0.1 to 50 mass% in the resin composition constituting the adhesive layer 37, and in the range of 0.5 to 40 mass %. More preferably. As a result, the adhesion between the corrosion resistant coating 36a and the adhesive layer 37 can be effectively enhanced.

The curing agent having an epoxy group is not particularly limited as long as it is a resin that can form a crosslinked structure by the epoxy group existing in the molecule, and a known epoxy resin can be used. The weight average molecular weight of the epoxy resin is preferably about 50 to 2000, more preferably about 100 to 1000, and further preferably about 200 to 800.

In addition, in this embodiment, the weight average molecular weight of the epoxy resin is a value measured by gel permeation chromatography (GPC), which is measured under the condition that polystyrene is used as a standard sample.

Specific examples of the epoxy resin include glycidyl ether derivatives of trimethylolpropane, bisphenol A diglycidyl ether, modified bisphenol A diglycidyl ether, novolac glycidyl ether, glycerin polyglycidyl ether, polyglycerin polyglycidyl ether, and the like. The epoxy resins may be used alone or in combination of two or more.

The proportion of the epoxy resin in the adhesive layer 37 is preferably in the range of 0.1 to 50% by mass, more preferably 0.5 to 40% by mass in the resin composition constituting the adhesive layer 37. .. As a result, the adhesion between the corrosion resistant coating 36a and the adhesive layer 37 can be effectively enhanced.

The thickness of the adhesive layer 37 is not particularly limited as long as it functions as an adhesive layer, but when the adhesive exemplified in the adhesive layer 35 is used, it is preferably about 1 to 10 μm, more preferably 1 to The thickness is about 5 μm.

When the resin exemplified as the heat-fusible resin layer 38 is used for the adhesive layer 37, the thickness of the adhesive layer 37 is preferably about 2 to 50 μm, more preferably about 10 to 40 μm.

Further, when a cured product of an acid-modified polyolefin and a curing agent is used for the adhesive layer 37, the thickness of the adhesive layer 37 is preferably about 30 μm or less, more preferably about 0.1 to 20 μm, and further preferably 0.1. The thickness is about 5 to 5 μm. When the adhesive layer 37 is a cured product of a resin composition containing an acid-modified polyolefin and a curing agent, the adhesive layer 37 can be formed by applying the resin composition and curing it by heating or the like.

(Surface coating layer 32)
The packaging materials 15 and 25 are, if necessary, on the outer side of the base material layer 34 (on the side opposite to the barrier layer 36 of the base material layer 34) for the purpose of improving designability, electrolytic solution resistance, abrasion resistance, moldability, and the like. ) Is provided with the surface coating layer 32. When the surface coating layer 32 is provided, the surface coating layer 32 becomes the outermost layer of the packaging materials 15 and 25.

The surface coating layer 32 can be formed of, for example, polyvinylidene chloride, polyester resin, urethane resin, acrylic resin, epoxy resin, or the like. Of these, the surface coating layer 32 is preferably formed of a two-component curable resin. Examples of the two-component curable resin forming the surface coating layer 32 include a two-component curable urethane resin, a two-component curable polyester resin, and a two-component curable epoxy resin. Moreover, you may mix|blend an additive with the surface coating layer 32.

Examples of the additive include fine particles having a particle size of about 0.5 nm to 5 μm. The material of the additive is not particularly limited, and examples thereof include metals, metal oxides, inorganic substances, organic substances and the like. Further, the shape of the additive is not particularly limited, and examples thereof include a spherical shape, a fibrous shape, a plate shape, an amorphous shape, and a balloon shape.

As the additive, specifically, talc, silica, graphite, kaolin, montmorillonite, montmorillonite, synthetic mica, hydrotalcite, silica gel, zeolite, aluminum hydroxide, magnesium hydroxide, zinc oxide, magnesium oxide, aluminum oxide, Neodymium oxide, antimony oxide, titanium oxide, cerium oxide, calcium sulfate, barium sulfate, calcium carbonate, calcium silicate, lithium carbonate, calcium benzoate, calcium oxalate, magnesium stearate, alumina, carbon black, carbon nanotubes, high Examples include melting point nylon, crosslinked acryl, crosslinked styrene, crosslinked polyethylene, benzoguanamine, gold, aluminum, copper and nickel.

These additives may be used alone or in combination of two or more. Among these additives, silica, barium sulfate and titanium oxide are preferable from the viewpoint of dispersion stability and cost. Further, the surface of the additive may be subjected to various surface treatments such as insulation treatment and high dispersibility treatment.

The content of the additive in the surface coating layer 32 is not particularly limited, but is preferably about 0.05 to 1.0 mass%, more preferably about 0.1 to 0.5 mass%.

The method of forming the surface coating layer 32 is not particularly limited, and examples thereof include a method of applying the two-component curable resin forming the surface coating layer 32 to the outer surface of the base material layer 34. When the additive is blended, the additive may be added to the two-component curable resin, mixed, and then applied.

The thickness of the surface coating layer 32 is not particularly limited as long as it exhibits the above-mentioned functions as the surface coating layer 32, but is, for example, about 0.5 to 10 μm, preferably about 1 to 5 μm.

(Method of manufacturing packaging materials 15 and 25)
The method for producing the packaging materials 15 and 25 having the above-described configuration is not particularly limited as long as a laminated body obtained by laminating each layer having a predetermined composition is obtained. That is, there is provided a step of stacking at least the base material layer 34, the barrier layer 36, and the heat-fusible resin layer 38 in this order to obtain a laminate. Further, when the barrier layer 36 is laminated, a corrosion resistant coating is provided on at least one surface of the barrier layer 36. The corrosion-resistant coatings 36a and 36b have a ratio P _{PO3 /CePO4} of a peak intensity P _PO3 derived from PO ₃ ⁻ to a peak intensity P _CePO4 derived from CePO ₄ ⁻ when analyzed using a time-of-flight secondary ion mass spectrometry. There range of 80 to 120, or PO ₂ to the peak intensity P _CePO4 ^- the ratio P _{PO2 / CePO4} the peak intensity P _PO2 derived is in the range of 90 to 150.

An example of the manufacturing method of the packaging materials 15 and 25 is shown below. First, a laminated body (hereinafter, may be referred to as “laminated body A”) in which the base material layer 34, the adhesive layer 35 provided as necessary, and the barrier layer 36 are laminated in order is formed.

Specifically, the laminated body A is formed by a dry laminating method. An adhesive agent for forming the adhesive layer 35 is applied to one of the base material layer 34 and the barrier layer 36 (corrosion resistant film 36b when the corrosion resistant film 36b is provided, omitted below) and dried, and the other is laminated to form an adhesive layer. Cure 35. The adhesive is applied by a coating method such as a gravure coating method or a roll coating method. At this time, the above-mentioned corrosion resistant film is previously formed on at least one surface of the barrier layer 36. The method for forming the corrosion resistant films 36a and 36b is as described above.

Next, the heat-fusible resin layer 38 is laminated on the barrier layer 36 of the laminate A. When the heat-fusible resin layer 38 is directly laminated on the barrier layer 36, the resin component constituting the heat-fusible resin layer 38 is gravure-coated or roll-coated on the barrier layer 36 of the laminate A. And the like.

When the adhesive layer 37 is provided between the barrier layer 36 and the heat-fusible resin layer 38, the heat-fusible resin layer 38 is laminated by a coextrusion laminating method, a sandwich laminating method, a thermal laminating method or the like. It

In the coextrusion laminating method, the adhesive layer 37 and the heat-fusible resin layer 38 are coextruded on the barrier layer 36 of the laminate A to form a laminate. In the sandwich laminating method, the melted adhesive layer 37 is poured between the barrier layer 36 of the laminate A and the heat-fusible resin layer 38 formed in a sheet shape in advance, so that the laminate A and the heat-fusible resin layer 38 are formed. Stick together.

In the thermal lamination method, a laminated body in which the adhesive layer 37 and the heat-fusible resin layer 38 are laminated is formed, and this is laminated on the barrier layer 36 of the laminated body A in a heated state. You may laminate|stack the adhesive agent which forms the adhesive layer 37 on the barrier layer 36 of the laminated body A, and laminate|stack the heat-fusible resin layer 38 previously formed in the sheet form in the heating state. At this time, the adhesive layer 37 can be laminated by a method in which an adhesive is applied onto the laminate A by an extrusion method or a solution coating method, dried at a high temperature and baked.

When the surface coating layer 32 is provided, the surface coating layer 32 is laminated on the surface of the base material layer 34 opposite to the barrier layer 36. The surface coating layer 32 can be formed, for example, by applying a resin forming the surface coating layer 32 to the surface of the base material layer 34. The order of the step of laminating the barrier layer 36 on the surface of the base material layer 34 and the step of laminating the surface coating layer 32 on the surface of the base material layer 34 is not particularly limited. For example, after forming the surface coating layer 32 on the surface of the base material layer 34, the barrier layer 36 may be formed on the surface of the base material layer 34 opposite to the surface coating layer 32.

As described above, the surface coating layer 32/the base material layer 34/if necessary, the adhesive layer 35/if necessary, the barrier layer 36 having a corrosion resistant film on at least one surface thereof/as the case requires A laminated body including the provided adhesive layer 37/heat-fusible resin layer 38 is formed. In order to strengthen the adhesiveness of the adhesive layer 35 and the adhesive layer 37, heat treatment such as hot roll contact type, hot air type, near infrared ray type or far infrared ray type may be applied.

Each layer constituting the laminate may be subjected to surface activation treatment such as corona treatment, blast treatment, oxidation treatment and ozone treatment, if necessary. This can improve or stabilize the film-forming properties of each layer, lamination processing, and final product secondary processing (pouching, embossing) suitability, and the like.

The above-mentioned peak intensity and the like can be analyzed by cutting the packaging materials 15 and 25 from the electricity storage device 10. When the packaging materials 15 and 25 are cut out, a sample can be obtained from a portion where the heat-fusible resin layers 38 are not heat-sealed and used for analysis.

4 and 5, the packaging material 25 is formed in a rectangular sheet shape. The packaging material 15 has a storage portion 16 and a flange portion 17. The storage portion 16 has a substantially rectangular opening 16 a on one surface and stores the storage element 11. The flange portion 17 is formed in an annular shape protruding from the peripheral edge of the opening 16a toward the outer peripheral side.

By heat-sealing the heat-sealable resin layers 38 (see FIG. 6) of the flange 17 and the packaging material 25 facing each other, an annular peripheral seal portion 21 (see FIG. 5) is formed along the periphery of the storage portion 16. To be done. As a result, the storage portion 16 is formed at a predetermined depth from the inner edge of the peripheral edge seal portion 21 and is sealed by the peripheral edge seal portion 21.

The packaging material 15 is formed by recessing the storage portion 16 in a predetermined depth with respect to the flange portion 17 by sheet molding. At this time, the storage part 16 is formed in a substantially rectangular shape extending in one direction in a plane perpendicular to the depth direction.

The depth of the accommodating portion 16 is determined according to the thickness of the barrier layer 36 of the packaging material 15 so that cracks and the like during molding do not occur. In this embodiment, the storage portion 16 is formed to have a depth of 5 mm to 10 mm with respect to the barrier layer 36 having a thickness of 40 μm. At this time, each corner R in the plane perpendicular to the depth direction of the storage portion 16 is formed to be, for example, about 3 mm, and each corner R in the plane parallel to the depth direction is formed to be, for example, about 1.5 mm. In addition, by increasing the thickness of the barrier layer 36, the depth of the storage portion 16 can be formed to, for example, 5 mm to 30 mm.

The electricity storage device 10 is arranged such that the depth direction (Y direction) of the storage unit 16 is the front-back direction of the electric vehicle 1. Further, the longitudinal direction (X direction, first direction) in the plane perpendicular to the depth direction of the storage portion 16 is arranged in the left-right direction of the electric vehicle 1, and the lateral direction (Z direction, second direction) is the electric vehicle. 1 is arranged in the height direction. That is, the X direction orthogonal to the depth direction of the storage unit 16 is arranged in the left-right direction of the electric vehicle 1, and the Z direction orthogonal to the depth direction of the storage unit 16 and the X direction is arranged in the height direction of the electric vehicle 1. To be done.

Since the storage portion 16 is formed by sheet molding, it is difficult to increase the depth. On the other hand, the storage portion 16 can easily make the lengths Ax and Az in two directions orthogonal to each other in the plane perpendicular to the depth direction larger than the length Ay in the depth direction. Therefore, by arranging the depth direction (Y direction) of the storage portion 16 in the front-back direction of the electric vehicle 1, the plurality of power storage devices 10 are installed in the electric vehicle 1 without stacking and the desired electric power is supplied. You can Therefore, it is possible to prevent damage to the exterior member 20 due to weighting when stacked, and improve the reliability of the electricity storage device 10.

In addition, in the case where the electrolyte is an electrolytic solution, when the electricity storage devices 10 are stacked in the depth direction (Y direction) of the storage section 16, the packaging material 25 is bent due to the weight and the electrolytic solution is pushed out to the peripheral portion. For this reason, the electrolyte solution between the positive electrode plate and the negative electrode plate in the central portion becomes insufficient, and the energy density of the electricity storage device 10 decreases. Therefore, the depth direction (Y direction) of the storage portion 16 can be arranged in the front-rear direction to prevent a decrease in energy density of the electricity storage device 10 containing the electrolytic solution.

Further, since the lateral direction (Z direction) in the plane perpendicular to the depth direction of the storage portion 16 is arranged in the height direction, the height of the electricity storage device 10 is reduced and the comfortability of the electric vehicle 1 is improved. be able to. At this time, since the storage portion 16 extends in the X direction and the length Ax in the X direction is larger than the length Az in the Z direction, it is possible to suppress the height and obtain the power storage device 10 having a large capacity.

The length Ax of the storage portion 16 in the X direction is formed to be 2 to 30 times the length Az in the Z direction. When the length Ax is smaller than twice the length Az, the capacity of the electricity storage device 10 becomes small. Therefore, the length Ax can be formed to be twice or more the length Az, and the capacity of the electricity storage device 10 can be increased. Further, if the length Ax exceeds 30 times the length Az, the packaging material 15 cannot be easily molded, and the yield is reduced. Therefore, the length Ax can be formed to be 30 times or less the length Az, and the yield at the time of molding the packaging material 15 can be improved.

Further, the peripheral edge seal portion 21 extending in the X direction protrudes in the Z direction at the time of heat fusion, as shown by the alternate long and short dash line 21 ′, and is bent after the heat fusion to be stacked on the peripheral wall of the storage portion 16. Thereby, the height of the electricity storage device 10 can be further reduced.

At this time, the flow direction (MD) of the packaging materials 15 and 25 made of the laminated body is arranged in the Z direction (perpendicular to the X direction). If the laminate is bent parallel to the flow direction, the possibility of cracks in the metal foil and pinholes in the resin film increases. Since the flow directions of the packaging materials 15 and 25 are orthogonal to the X direction, it is possible to suppress the occurrence of cracks and pinholes in the exterior member 20 when the peripheral edge seal portion 21 extending in the X direction is bent.

The flow direction (MD) of the packaging materials 15 and 25 corresponds to the rolling direction (RD) of the metal foil (aluminum alloy foil or the like) of the barrier layer 36. The TD of the packaging materials 15 and 25 corresponds to the TD of the metal foil. The rolling direction (RD) of the metal foil can be identified by the rolling pattern.

Further, the sea-island structure is confirmed by observing a plurality of cross sections of the heat-fusible resin layer 38 of the packaging materials 15 and 25 with an electron microscope, and the diameter of the island in the direction perpendicular to the thickness direction of the heat-fusible resin layer 38. The direction parallel to the cross section in which the average of is maximum can be determined as MD. When the MD of the packaging materials 15 and 25 cannot be specified due to the rolled grain of the metal foil, the MD can be specified by this method.

Specifically, the angle in the longitudinal direction of the heat-fusible resin layer 38 and the direction parallel to the longitudinal cross-section are changed by 10 degrees, respectively, to the direction perpendicular to the longitudinal cross-section. The sea-island structure is confirmed by observing each cross section (total of 10 cross sections) with an electron micrograph. Next, for each island on each cross section, the diameter d of the island is measured by the linear distance connecting both ends in the direction perpendicular to the thickness direction of the heat-fusible resin layer 38. Next, the average of the diameters d of the top 20 islands from the largest one is calculated for each cross section. Then, the direction parallel to the cross section in which the average of the island diameters d is the largest is determined as MD.

The electrode terminal 12 and the electrode terminal 13 extend in the Z direction and project from the peripheral seal portions 21 facing each other in the X direction. Therefore, the height of the electricity storage device 10 can be further reduced. Further, when the electrode terminals 12 and 13 approach each other, the temperature increase in the vicinity of the electrode terminals 12 and 13 becomes large, so that the electricity storage device 10 easily deteriorates with age. Therefore, by disposing the electrode terminal 12 and the electrode terminal 13 apart from each other in the X direction, it is possible to suppress aged deterioration of the electricity storage device 10.

The electricity storage device 10 is manufactured by performing a packaging step of packaging the electricity storage element 11 with the exterior member 20 after the step of preparing the molded exterior member 20. In addition, a folding process is provided after the packaging process as needed.

In the forming step of forming the exterior member 20, the roll-shaped laminated body is cut into a predetermined length, and the storage portion 16 is recessed in the flange portion 17 by cold forming to form the packaging material 15. At this time, the packaging materials 15 and 25 are formed by arranging the flow direction (MD) of the roll-shaped laminate in the Z direction. The exterior member 20 may be prepared by a molding process, or the exterior member 20 that has been molded may be obtained and the exterior member 20 may be prepared.

In the packaging step, the electrode terminals 12 and 13 are arranged on the flange portion 17, the storage element 11 is stored in the storage portion 16, and the storage portion 16 is filled with the electrolytic solution. Next, the packaging material 25 is heat-sealed to the flange portion 17 of the packaging material 15 to form the peripheral edge seal portion 21 along the periphery of the storage portion 16, and the storage portion 16 is sealed. As a result, the storage element 11 is packaged by the exterior member 20.

In the bending step, the peripheral seal portion 21 extending in the X direction perpendicular to the flow direction of the laminated body is bent and overlapped on the peripheral wall of the storage portion 16.

In FIG. 3 described above, the electricity storage device pack 5 is formed by arranging a plurality of electricity storage devices 10 in parallel in the Y direction, and is installed in the electric vehicle 1 in one step in the height direction. The plurality of power storage device packs 5 may be arranged in the X direction or the Y direction and installed in the electric vehicle 1.

The length Bz of the power storage device pack 5 in the Z direction is formed to be substantially the same as the length Az of the storage portion 16 of the power storage device 10 in the Z direction. The length Bx of the power storage device pack 5 in the X direction is formed to be substantially the same as the length of the power storage device 10 in the X direction. Since the power storage devices 10 are arranged in parallel in the Y direction, the length By of the power storage device pack 5 in the Y direction is larger than the length Bz in the Z direction.

When the electric vehicle 1 is a sedan type or a compact car type, the height of the electricity storage device pack 5 (the length Bz in the Z direction) is formed to 100 mm or less, for example. When the electric vehicle 1 is the SUV type or the one-box type, the height (length Bz in the Z direction) of the electricity storage device pack 5 is formed to be 150 mm or less, for example.

According to the present embodiment, the electricity storage device 10 is arranged such that the depth direction (Y direction) of the storage portion 16 of the exterior member 20 is the front-back direction of the electric vehicle 1. Further, the X direction (first direction) orthogonal to the depth direction of the storage portion 16 is arranged in the left-right direction of the electric vehicle 1. The Z direction (second direction) orthogonal to the depth direction and the X direction of the storage unit 16 is arranged in the height direction of the electric vehicle 1. That is, the X direction (first direction) and the Z direction (second direction) orthogonal to each other in the plane perpendicular to the depth direction of the storage portion 16 are arranged in the left-right direction and the height direction of the electric vehicle 1, respectively.

Thereby, it is possible to install a plurality of power storage devices 10 on the electric vehicle 1 without stacking them and supply a desired electric power. Therefore, it is possible to prevent damage to the exterior member 20 due to weighting when stacked, and improve the reliability of the electricity storage device 10. Further, when the electricity storage device 10 contains the electrolytic solution, the depth direction (Y direction) of the storage portion 16 can be arranged in the front-rear direction to prevent a decrease in energy density of the electricity storage device 10.

Further, since the lateral direction (Z direction) in the plane perpendicular to the depth direction of the storage portion 16 is arranged in the height direction, the length Ax of the storage portion 16 in the X direction is larger than the length Az in the Z direction. large. As a result, the height of the electricity storage device 10 can be reduced to improve the comfortability of the electric vehicle 1, and the electricity storage device 10 having a large capacity can be obtained.

Further, since the length Ax of the storage portion 16 in the X direction is 2 to 30 times the length Az in the Z direction, the power storage device 10 having a large capacity can be obtained and the yield of the exterior member 20 can be improved. ..

Moreover, since the peripheral edge seal portion 21 extending in the X direction is bent and overlapped on the peripheral wall of the storage portion 16, the height of the electricity storage device 10 can be further reduced.

Further, since the flow directions of the packaging materials 15 and 25 are orthogonal to the X direction, it is possible to suppress the generation of cracks and pinholes in the exterior member 20 when the peripheral edge seal portion 21 extending in the X direction is bent.

Moreover, since the electrode terminal 12 and the electrode terminal 13 project from the peripheral edge seal portion 21 extending in the Z direction, the height of the electricity storage device 10 can be further reduced.

Moreover, since the electrode terminal 12 and the electrode terminal 13 respectively project from the peripheral edge seal portions 21 facing each other in the X direction, it is possible to suppress the deterioration over time of the electricity storage device 10.

In addition, the electricity storage device pack 5 (electricity storage device aggregate) is formed by arranging the electricity storage devices 10 side by side in the depth direction (Y direction) of the storage unit 16, and the length By of the electricity storage device pack 5 in the Y direction is the Z direction. Is greater than the length Bz. This makes it possible to reduce the height of the electricity storage device pack 5 and supply desired power.

Moreover, since the power storage device packs 5 are installed in one step in the height direction of the electric vehicle 1, the comfortability of the electric vehicle 1 can be improved.

<Second Embodiment>
Next, FIGS. 11 and 12 show an exploded perspective view and a side sectional view of the electricity storage device 10 of the second embodiment. For convenience of explanation, the same parts as those in the first embodiment shown in FIGS. 1 to 6 are given the same reference numerals. In this embodiment, the shape of the packaging material 25 is different from that of the first embodiment, and the other portions are the same as those of the first embodiment.

The packaging material 25 has a storage portion 26 and a flange portion 27 like the packaging material 15. The storage portion 26 has a substantially rectangular opening 26a on one surface. The storage element 11 is stored in the storage portion 16 of the packaging material 15 and the storage portion 26 of the packaging material 25. The flange portion 27 is formed in an annular shape protruding from the peripheral edge of the opening 26a toward the outer peripheral side.

By heat-sealing the heat-fusible resin layers 38 (see FIG. 6) of the flange portion 17 and the flange portion 27, an annular peripheral edge seal portion 21 is formed along the circumference of the storage portion 16 and the storage portion 26. As a result, the storage portion 16 and the storage portion 26 formed at a predetermined depth from the inner edge of the peripheral edge seal portion 21 are sealed by the peripheral edge seal portion 21.

Further, the peripheral edge seal portion 21 extending in the X direction is projected in the Z direction as indicated by a chain line 21' during heat fusion, and is bent after heat fusion and is stacked on the peripheral wall of the storage portion 16 or the storage portion 26.

The electricity storage device 10 is arranged such that the depth direction (Y direction) of the storage units 16 and 26 is in the front-rear direction of the electric vehicle 1. In addition, the longitudinal direction (X direction) in the plane perpendicular to the depth direction of the storage units 16 and 26 is arranged in the left-right direction of the electric vehicle 1, and the lateral direction (Z direction) is the height direction of the electric vehicle 1. Will be placed.

Thereby, the same effect as that of the first embodiment can be obtained. Moreover, since the packaging material 15 and the packaging material 25 respectively include the storage portion 16 and the storage portion 26, the volume of the power storage element 11 can be increased and the capacity of the power storage device 10 can be increased. Therefore, the number of power storage devices 10 forming the power storage device pack 5 (see FIG. 3) can be reduced, and the number of manufacturing steps of the power storage device pack 5 can be reduced.

As shown in FIG. 13, the electricity storage device 10 may be covered with protective covers 8 and 9. The protective covers 8 and 9 are formed by injection molding into a bottomed tubular shape having a rectangular cross section with an opening on one surface. Further, the outer shape of the protective cover 9 is formed smaller than the opening of the protective cover 8.

The protective cover 9 is bent along the peripheral wall of the peripheral seal portion 21 protruding to the peripheral portion of the exterior member 20, and the protective cover 8 is fitted onto the protective cover 9 along the peripheral seal portion 21. As a result, the peripheral edge seal portion 21 is bent at a position away from the peripheral edges of the openings 16a and 26a (see FIG. 11) of the storage portions 16 and 26. Therefore, it is possible to reduce the occurrence of cracks and pinholes due to the bending of the peripheral edge seal portion 21.

FIG. 14 shows an electricity storage device 10 covered with protective covers 8 and 9 having a shape different from that of FIG. The protective covers 8 and 9 are formed into substantially the same shape by injection molding, and are formed into a bottomed cylinder having an opening on one surface. The electricity storage device 10 does not require a bending step, and the protective covers 8 and 9 are fixed in a state in which the peripheral seal portion 21 protruding to the peripheral portion of the exterior member 20 is sandwiched by the peripheral walls of the protective covers 8 and 9. As a result, the peripheral edge seal portion 21 is protected. Since the bending step is omitted, it is possible to reduce the occurrence of cracks and pinholes due to bending of the peripheral edge seal portion 21.

The exterior member 20 of the electricity storage device 10 of the first embodiment may be covered with the same protective covers 8 and 9.

<Third Embodiment>
Next, FIG. 15 shows an exploded perspective view of the electricity storage device 10 of the third embodiment. For convenience of explanation, the same parts as those in the second embodiment shown in FIGS. 11 and 12 described above are designated by the same reference numerals. In this embodiment, the packaging material 15 and the packaging material 25 are formed of a single member. Other parts are the same as those in the second embodiment.

In the exterior member 20, a packaging material 15 having a storage portion 16 and a packaging material 25 having a storage portion 26 are integrally formed continuously in the Z direction. The flange portion 17 of the packaging material 15 and the flange portion 27 of the packaging material 25 are formed flush with each other via the folding line 20a.

After disposing the storage element 11 in the storage portion 16 or the storage portion 26, the exterior member 20 is bent along the fold line 20a extending in the X direction. Then, the flange portions 17 and 27 facing each other are heat-sealed to form the peripheral edge seal portion 21.

According to this embodiment, the same effect as that of the second embodiment can be obtained. Moreover, since the packaging material 15 and the packaging material 25 are formed of a single member, the number of parts of the electricity storage device 10 can be reduced.

In the present embodiment, the openings 16a and 26a may be arranged close to each other, and the folding line 20a may be provided along the periphery of the openings 16a and 26a. Thereby, the lower surface of the electricity storage device 10 can be formed flat. Therefore, the adhesion between the installation surface on which the electricity storage device 10 is installed and the electricity storage device 10 is increased, and the heat dissipation of the electricity storage device 10 can be improved.

The wrapping material 15 and the wrapping material 25 of the first and second embodiments may be formed of a single member that is continuously provided via a folding line at the lower end.

<Fourth Embodiment>
Next, FIG. 16 shows a top view of the electric vehicle 1 of the fourth embodiment. For convenience of explanation, the same parts as those in the first embodiment shown in FIGS. 1 to 6 are given the same reference numerals. The present embodiment is different from the first embodiment in the arrangement of the electricity storage device pack 5. Other parts are the same as those in the first embodiment.

The electricity storage device pack 5 is installed under the floor of the vehicle body of the electric vehicle 1, and the electricity storage devices 10 are arranged side by side in the left-right direction of the electric vehicle 1. Thereby, the electricity storage device 10 is arranged in the depth direction (Y direction) of the storage portion 16 (see FIG. 4) in the left-right direction of the electric vehicle 1. Further, the longitudinal direction (X direction, first direction) in the plane perpendicular to the depth direction of the storage portion 16 is arranged in the left-right direction of the electric vehicle 1, and the lateral direction (Z direction, second direction) is the electric vehicle. 1 is arranged in the height direction. That is, the X direction orthogonal to the depth direction of the storage unit 16 is arranged in the front-back direction of the electric vehicle 1, and the Z direction orthogonal to the depth direction of the storage unit 16 and the X direction is arranged in the height direction of the electric vehicle 1. To be done.

Thereby, it is possible to install a plurality of power storage devices 10 on the electric vehicle 1 without stacking them and supply a desired electric power. Therefore, the same effect as the first embodiment can be obtained. Further, the air taken in through the front grille on the front side when the electric vehicle 1 travels flows rearward and comes into contact with each power storage device 10 of the power storage device pack 5. Therefore, the power storage device 10 can be cooled.

The power storage device 10 of the second embodiment or the third embodiment may be installed in the electric vehicle 1, and the electric storage devices 10 may be arranged side by side in the left-right direction of the electric vehicle 1.

In the first to fourth embodiments, the cross-sectional shape of the storage portions 16 and 26 perpendicular to the Y direction is formed into a substantially rectangular shape, but other shapes such as an ellipse, an ellipse, and a polygon may be used.

Further, although the electricity storage device 10 that supplies electric power to the drive motor 3 is composed of a secondary battery, it may be a capacitor (electrolytic capacitor, electric double layer capacitor, lithium ion capacitor, etc.).

Examples and comparative examples formed to evaluate the characteristics of the packaging materials 15 and 25 forming the outer container 6 of the electricity storage device 10 will be described below.

The packaging material 15 of Example 1 is formed by the above-mentioned laminated structure shown in FIG. As the base material layer 34, a biaxially stretched polyethylene terephthalate film having a thickness of 5 μm and a biaxially stretched nylon film having a thickness of 20 μm were laminated. The biaxially stretched polyethylene terephthalate film and the biaxially stretched nylon film are bonded by an adhesive (thickness 1 μm) using a resin composition containing a modified thermoplastic resin graft-modified with an unsaturated carboxylic acid derivative component. There is.

The barrier layer 36 was formed of an aluminum foil (JIS H4160:1994 A8021H-O) having a thickness of 40 μm, and provided with corrosion resistant coatings 36a and 36b having a thickness of 20 nm on both surfaces. The heat-fusible resin layer 38 was formed of an unstretched polypropylene film having a thickness of 40 μm. The polypropylene film is formed by laminating random polypropylene (thickness 5 μm), block polypropylene (thickness 30 μm) and random polypropylene (thickness 5 μm).

The adhesive layer 35 between the base material layer 34 and the barrier layer 36 was formed of a two-component urethane adhesive (polyol compound and aromatic isocyanate-based compound) with a thickness of 3 μm. The adhesive layer 37 between the barrier layer 36 and the heat-fusible resin layer 38 was formed by an adhesive (thickness after curing was 3 μm) composed of an acid-modified polyolefin resin having a carboxyl group and a polyfunctional isocyanate compound.

The method of forming the packaging material 15 is as follows. First, the treatment liquid was applied to both surfaces of the aluminum foil forming the barrier layer 36 and dried to form the corrosion resistant films 36a and 36b. The treatment liquid contains 20 parts by mass of an inorganic phosphorus compound (sodium phosphate) with respect to 100 parts by mass of cerium oxide, and contains water as a solvent. The solid content concentration of the treatment liquid is about 10% by mass. The treatment liquid was dried by heating the surface temperature of the barrier layer 36 at about 190 to 230° C. for about 3 to 6 seconds.

Next, the biaxially stretched nylon film side of the base material layer 34 and the barrier layer 36 were laminated via the adhesive layer 35 by a dry laminating method, and cured by an aging treatment to form a laminate A. Next, an adhesive for forming the adhesive layer 37 is applied onto the barrier layer 36 and dried, and a laminated film for forming the heat-fusible resin layer 38 is superposed and passed through two heated rolls for adhesion. .. Next, the obtained laminated body was subjected to an aging treatment to obtain a packaging material 15.

As a result, the laminated structure of the packaging material 15 of Example 1 had a biaxially stretched polyethylene terephthalate film (5 μm)/adhesive (1 μm)/biaxially stretched nylon film (20 μm)/adhesive layer (3 μm)/acid resistance on both sides. It is a barrier layer (40 μm) provided with a conductive film (thickness 20 nm)/adhesive layer (3 μm)/unstretched polypropylene film (40 μm).

The packaging material 15 of the second embodiment is formed by the above-mentioned laminated structure shown in FIG. The heat-fusible resin layer 38 was formed of an unstretched polypropylene film having a thickness of 80 μm. The polypropylene film is formed by laminating random polypropylene (thickness 10 μm), block polypropylene (thickness 60 μm), and random polypropylene (thickness 10 μm). The other layer structure and the stacking method are the same as in the first embodiment.

As a result, the laminated structure of the packaging material 15 of Example 2 had a biaxially oriented polyethylene terephthalate film (5 μm)/adhesive (1 μm)/biaxially oriented nylon film (20 μm)/adhesive layer (3 μm)/acid resistance on both sides. It is a barrier layer (40 μm) provided with a conductive film (thickness 20 nm)/adhesive layer (3 μm)/unstretched polypropylene film (80 μm).

[Comparative Example 1]
The packaging material 15 of Comparative Example 1 is formed by the above-described laminated structure shown in FIG. The base material layer 34 was formed of a biaxially stretched nylon film having a thickness of 25 μm. The barrier layer 36 was formed of an aluminum foil (JIS H4160:1994 A8021H-O) having a thickness of 40 μm, and provided with corrosion-resistant coatings 36a and 36b containing chromium having a thickness of 20 nm on both surfaces.

The heat-fusible resin layer 38 was formed of an unstretched polypropylene film having a thickness of 30 μm and a random polypropylene film having a thickness of 50 μm. The polypropylene film is formed by laminating random polypropylene (thickness 4 μm), block polypropylene (thickness 22 μm) and random polypropylene (thickness 4 μm).

The adhesive layer 35 between the base material layer 34 and the barrier layer 36 was formed of a two-component urethane adhesive (polyol compound and aromatic isocyanate-based compound) with a thickness of 3 μm. The adhesive layer 37 between the barrier layer 36 and the heat-fusible resin layer 38 is formed by an adhesive (thickness after curing is 3 μm) composed of a non-crystalline polyolefin resin having a carboxyl group and a polyfunctional isocyanate compound. ..

The method of forming the packaging material 15 is as follows. First, the treatment liquid was applied to both surfaces of the aluminum foil forming the barrier layer 36 and dried to form the corrosion resistant films 36a and 36b. The treatment liquid contains 43 parts by mass of aminated phenol polymer, 16 parts by mass of chromium fluoride, and 13 parts by mass of phosphoric acid with respect to 100 parts by mass of water. The treatment liquid was dried by heating the surface temperature of the barrier layer 36 at about 190 to 230° C. for about 3 to 6 seconds.

Next, the biaxially stretched nylon film forming the base material layer 34 and the barrier layer 36 were laminated via the adhesive layer 35 by a dry lamination method, and subjected to aging treatment to form a laminate A. Next, an adhesive for forming the adhesive layer 37 was applied onto the barrier layer 36, dried, and an unstretched polypropylene film was overlapped and passed between two heated rolls for adhesion. Further, random polypropylene was extruded from above and subjected to aging treatment to obtain a packaging material 15.

As a result, the laminated structure of the packaging material 15 of Comparative Example 1 had a biaxially stretched nylon film (25 μm)/adhesive layer (3 μm)/barrier layer (40 μm)/corrosion resistant coating (thickness 20 nm) on both sides/adhesive layer. (3 μm)/unstretched polypropylene film (30 μm)/random polypropylene (50 μm).

[Comparative example 2]
The thickness of the random polypropylene forming the heat-fusible resin layer 38 of the packaging material 15 of Comparative Example 2 is different from that of Comparative Example 1 and is 20 μm. The other layer structure and the stacking method are the same as those in Comparative Example 1.

As a result, the laminated structure of the packaging material 15 of Comparative Example 2 had a biaxially stretched nylon film (25 μm)/adhesive layer (3 μm)/barrier layer (40 μm)/corrosion resistant coating (thickness 20 nm) on both sides/adhesive layer. (3 μm)/unstretched polypropylene film (30 μm)/random polypropylene (20 μm).

[Comparative Example 3]
The packaging material 15 of Comparative Example 3 is formed in the same manner as in Example 1, and the concentration of phosphoric acid in the treatment liquid is about 1/2 times (mass ratio) that of Example 1 when the corrosion resistant films 36a and 36b are formed. The other laminated structure and forming method are the same as those in the first embodiment.

[Comparative Example 4]
The packaging material 15 of Comparative Example 4 is formed in the same manner as in Example 1, and the concentration of phosphoric acid in the treatment liquid is about 1.5 times (mass ratio) that of Example 1 when forming the corrosion resistant films 36a and 36b. The other laminated structure and forming method are the same as those in the first embodiment.

An analysis test of the corrosion resistant coating 36a and an evaluation test of the adhesiveness of the barrier layer 36 were carried out for each of the examples and the comparative examples. Table 1 shows the analysis results and the evaluation test results.

<Time-of-flight secondary ion mass spectrometry>
The analysis of the corrosion resistant coating 36a was performed by using the time-of-flight secondary ion mass spectrometry. The test piece for analysis peeled off between the barrier layer 36 and the adhesive layer 37 to expose the barrier layer 36. At this time, physical peeling was performed without using water, an organic solvent, an acid aqueous solution, an alkaline aqueous solution, or the like. The adhesive layer 37 remaining on the surface of the peeled barrier layer 36 was removed by etching with Ar-GCIB.

As a result, the corrosion resistant coating 36a on the barrier layer 36 was analyzed using the time-of-flight secondary ion mass spectrometry. The details of the measuring device and the measuring conditions of the time-of-flight secondary ion mass spectrometry are as follows.

Measuring device: Time-of-flight secondary ion mass spectrometer TOF. manufactured by ION-TOF. SIMS 5
(Measurement condition)
Primary ion: Double-charged bismuth cluster ion (Bi ₃ ⁺⁺ ).
Primary ion acceleration voltage: 30 kV
Mass range (m/z): 0 to 1500
Measuring range: 100 μm×100 μm
Number of scans: 16 scan/cycle
Number of pixels (1 side): 256 pixels
Etching ions: Ar gas cluster ion beam (Ar-GCIB)
Etching ion acceleration voltage: 5.0 kV

Table 1 shows peak intensities P _CePO4 , P _PO2 , and P _PO3 derived from CePO ₄ ⁻ , PO ₂ ⁻ , and PO ₃ ⁻ obtained by time-of-flight secondary ion mass spectrometry. Also shows the ratio P _{PO3 / CePO4} the peak intensity P _PO3 for the ratio P _{PO2 / CePO4,} peak intensity P _CePO4 the peak intensity P _PO2 to the peak intensity P _CePO4.

In Comparative Examples 1 and 2, chromium was used as the treatment liquid for the chemical conversion treatment and cerium was not used. Therefore, in Table 1, items regarding the peak intensity PCePO ₄ of CePO ₄ ⁻ are indicated by “−”.

<Adhesion evaluation>
The adhesion between the barrier layer 36 and the heat-fusible resin layer 38 was evaluated by measuring the peel strength (unit: N/15 mm). The test piece was formed by cutting the packaging material 15 into a size of 15 mm in TD (Transverse Direction, horizontal direction) and 100 mm in MD (Machine Direction, vertical direction).

The initial adhesion was determined by measuring the peel strength of the prepared test piece by a tensile test. Adhesion after immersion in the electrolytic solution was measured by peeling strength of the test piece after immersion in the electrolytic solution by a tensile test as described below.

The immersion of the electrolytic solution was carried out by placing the test piece and the electrolytic solution in a glass bottle, immersing the whole test piece in the electrolytic solution, sealing the glass bottle with a lid. As the electrolytic solution, lithium hexafluorophosphate (concentration in solution: 1×10 ³ mol/m ³ ) was added to a mixed solution of ethylene carbonate:diethyl carbonate:dimethyl carbonate=1:1:1 in volume ratio.

Then, the sealed glass bottle was placed in an oven set at 85° C. and left standing for 24 hours. Next, the glass bottle was taken out from the oven, the test piece taken out from the glass bottle was washed with water, and the water on the surface was wiped off with a towel. Then, the peel strength was measured within 10 minutes after the water on the surface of the test piece was wiped off with a towel.

The tensile test was performed using a tensile tester (AGS-XPlus manufactured by Shimadzu Corporation). The barrier layer 36 and the heat-fusible resin layer 38 of the test piece were peeled off in the lengthwise direction by about 20 mm and attached to the tester at a distance between marked lines of 50 mm, and the tester set the speed at 50 mm/min to 180°. The test piece was pulled in the direction. Then, the strength when the distance between marked lines reached 57 mm was defined as the peel strength of the test piece. When the barrier layer 36 and the heat-fusible resin layer 38 are separated from each other, the adhesive layer 37 is attached to either one or both of the barrier layer 36 and the heat-fusible resin layer 38.

Table 1 shows the peel strength (N/15 mm) indicating the initial adhesion, the peel strength (N/15 mm) indicating the adhesion after immersion in the electrolyte, and the retention rate (%) of the peel strength after immersion in the electrolyte with respect to the initial stage. Showing. As for the retention rate of peeling strength, the ratio of peeling strength after immersion in the electrolytic solution is derived with the initial peeling strength as 100%.

As is clear from Table 1, the packaging materials 15 of Examples 1 and 2 have CePO when the corrosion-resistant coating 36a provided on the surface of the barrier layer 36 is analyzed using time-of-flight secondary ion mass spectrometry. The ratio P _{PO3 /CePO4} of the peak intensity P _PO3 derived from PO ₃ ⁻ to the peak intensity P _CePO4 derived from ₄ ⁻ is in the range of 80 to 120.

At this time, although the packaging materials 15 of Examples 1 and 2 are provided with the corrosion-resistant coating 36a on the surface of the barrier layer 36, the barrier layer 36 and the heat-fusible resin layer 38 are formed after immersion in the electrolytic solution. It can be seen that the adhesion between them is excellent.

In addition, the packaging materials 15 of Examples 1 and 2 have peaks derived from CePO ₄ ⁻ when the corrosion-resistant coating 36a provided on the surface of the barrier layer 36 is analyzed using time-of-flight secondary ion mass spectrometry. PO ₂ for the intensity P _CePO4 ^- the ratio P _{PO2 / CePO4} the peak intensity P _PO2 derived is in the range of 90 to 150. At this time, it can be seen that the adhesiveness between the barrier layer 36 and the heat-fusible resin layer 38 is excellent after the immersion in the electrolytic solution.

INDUSTRIAL APPLICABILITY According to the present invention, it can be widely used for electric vehicles equipped with a power storage device.

DESCRIPTION OF SYMBOLS 1 Electric vehicle 2 Wheels 3 Drive motor 5 Storage device pack 6 Exterior container 10 Storage device 11 Storage device 12, 13 Electrode terminal 15, 25 Packaging material 16, 26 Storage part 16a, 26a Opening part 17, 27 Flange part 20 Exterior member 20a Folding line 21 Peripheral seal part 32 Surface coating layer 34 Base material layer 35 Adhesive layer 36 Barrier layers 36a, 36b Corrosion resistant film 37 Adhesive layer 38 Thermal adhesive resin layer

Claims (26)

An electricity storage device, which is mounted in an electric vehicle as a drive source, in which an electricity storage element is enclosed in an exterior member formed of a laminate including at least a base material layer, a barrier layer, and a heat-fusible resin layer in this order. A member has a peripheral edge seal part and an accommodating part that is formed at a predetermined depth from the inner edge of the peripheral edge seal part and that accommodates the storage element, and the depth direction of the accommodating part and the depth of the accommodating part. A first direction orthogonal to the direction is arranged in the front-rear direction or the left-right direction of the electric vehicle, and a depth direction of the storage section and a second direction orthogonal to the first direction are arranged in the height direction of the electric vehicle. ,
A surface of at least one side of the barrier layer is provided with a corrosion resistant film, and when the corrosion resistant film is analyzed using a time-of-flight secondary ion mass spectrometry method, it has a peak intensity P _{CePO 4} derived from CePO ₄ ⁻ . PO ₃ ^- the ratio P _{PO3 / CePO4} the peak intensity P _PO3 derived from, in the range of 80 to 120, or PO ₂ with respect to the peak intensity P _CePO4 ^- the ratio P _{PO2 / CePO4} from the peak intensity P _PO2, An electric storage device having a range of 90 to 150. The power storage device according to claim 1, wherein the length of the storage portion in the first direction is larger than the length in the second direction. The electricity storage device according to claim 2, wherein the length of the storage portion in the first direction is 2 to 30 times the length in the second direction. The electricity storage device according to any one of claims 1 to 3, wherein the peripheral edge seal portion extending in the first direction is bent and overlapped on a peripheral wall of the storage portion. The electricity storage device according to claim 4, wherein a flow direction of the exterior member is orthogonal to the first direction. The electric storage element has a first electrode terminal and a second electrode terminal, and the first electrode terminal and the second electrode terminal protrude from the peripheral edge seal portion extending in the second direction. ~ The electricity storage device according to claim 5. The electricity storage device according to claim 6, wherein the first electrode terminal and the second electrode terminal respectively project from the peripheral edge seal portions facing each other in the first direction. The electricity storage device according to claim 1, wherein the surface of the barrier layer on the heat fusion resin layer side is provided with the corrosion resistant coating. The electricity storage device according to claim 8, wherein the corrosion-resistant coating and the heat-fusible resin layer are laminated via an adhesive layer. The electric storage device according to claim 9, wherein the resin forming the adhesive layer has a polyolefin skeleton. The electricity storage device according to claim 9 or 10, wherein the adhesive layer contains an acid-modified polyolefin. The electricity storage device according to claim 11, wherein the acid-modified polyolefin contained in the adhesive layer is maleic anhydride-modified polypropylene, and the heat-fusible resin layer contains polypropylene. 13. The electricity storage device according to claim 9, wherein a peak derived from maleic anhydride is detected when the adhesive layer is analyzed by infrared spectroscopy. The adhesive layer is a cured product of a resin composition containing at least one selected from the group consisting of a compound having an isocyanate group, a compound having an oxazoline group, and a compound having an epoxy group. The electricity storage device according to any one of claims 9 to 13. The adhesive layer is a cured product of a resin composition containing a curing agent having at least one selected from the group consisting of an oxygen atom, a heterocycle, a C═N bond, and a C—O—C bond. The electricity storage device according to any one of claims 9 to 13. 14. The electricity storage device according to claim 9, wherein the adhesive layer contains at least one selected from the group consisting of urethane resin, ester resin, and epoxy resin. The electric storage device according to claim 1, wherein the barrier layer is made of aluminum foil. 18. The electricity storage device according to claim 1, wherein the resin forming the heat-fusible resin layer contains a polyolefin skeleton. A plurality of the power storage devices according to any one of claims 1 to 18 are arranged side by side in a depth direction of the storage unit and housed in an outer container, and the plurality of power storage device aggregates are mounted on an electric vehicle. A power storage device aggregate, wherein a length in a direction in which power storage devices are arranged in parallel is larger than a length in the second direction. 20. The electricity storage device aggregate according to claim 19, a drive motor supplied with electric power from the electricity storage device aggregate, and wheels driven by the drive motor, wherein the electricity storage device aggregate is in a height direction at a bottom of a vehicle body. An electric vehicle characterized in that it is arranged in a single stage. An exterior member for an electricity storage device that encloses an electricity storage element of an electricity storage device mounted as a drive source in an electric vehicle, which is a laminate including at least a base material layer, a barrier layer, and a heat-fusible resin layer in this order. A storage part for opening the opening on one surface to have a predetermined depth and storing the storage element, and a flange projecting from the peripheral edge of the opening to the outer peripheral side and heat-sealing the second packaging material. And a length of the storage portion in a predetermined first direction is larger than a length in a second direction orthogonal to the first direction in a plane perpendicular to the depth direction of the storage portion. The flow direction of the body is orthogonal to the first direction,
A surface of at least one side of the barrier layer is provided with a corrosion resistant film, and when the corrosion resistant film is analyzed using a time-of-flight secondary ion mass spectrometry method, it has a peak intensity P _{CePO 4} derived from CePO ₄ ⁻ . PO ₃ ^- the ratio P _{PO3 / CePO4} the peak intensity P _PO3 derived from, in the range of 80 to 120, or PO ₂ with respect to the peak intensity P _CePO4 ^- the ratio P _{PO2 / CePO4} from the peak intensity P _PO2, An exterior member for an electricity storage device, which is in the range of 90 to 150. The exterior member for an electricity storage device according to claim 10, wherein the length of the storage portion in the first direction is 2 to 30 times the length in the second direction. In a method of manufacturing an electricity storage device to be mounted as a drive source in an electric vehicle, at least a base material layer, a barrier layer, and a heat-fusible resin layer are provided in this order as an exterior member provided with an accommodating portion by a laminate. And a step of accommodating the storage element in the accommodating part and packaging the accommodating element in the accommodating part, the depth direction of the accommodating part and the first direction orthogonal to the depth direction of the accommodating part of the electric vehicle being The storage unit is arranged in the front-rear direction or the left-right direction, and the depth direction of the storage unit and the second direction orthogonal to the first direction are disposed in the height direction of the electric vehicle, and the storage unit has a length in the first direction. Is larger than the length in the second direction,
A surface of at least one side of the barrier layer is provided with a corrosion resistant film, and when the corrosion resistant film is analyzed using a time-of-flight secondary ion mass spectrometry method, it has a peak intensity P _{CePO 4} derived from CePO ₄ ⁻ . PO ₃ ^- the ratio P _{PO3 / CePO4} the peak intensity P _PO3 derived from, in the range of 80 to 120, or PO ₂ with respect to the peak intensity P _CePO4 ^- the ratio P _{PO2 / CePO4} from the peak intensity P _PO2, A method for manufacturing an electricity storage device, which is in the range of 90 to 150. The method of manufacturing an electricity storage device according to claim 12, wherein the length of the storage portion in the first direction is 2 to 30 times the length in the second direction. In the step of packaging with the exterior member, a peripheral edge seal portion for sealing the exterior member by heat fusion of the heat-fusible resin layer is formed on a peripheral portion of the exterior member, and the peripheral edge extending in the second direction. The method for manufacturing an electricity storage device according to claim 12 or 13, wherein the seal portion is bent and overlapped on the peripheral wall of the storage portion. The method for manufacturing an electricity storage device according to claim 14, wherein the first direction is orthogonal to the flow direction of the exterior member.

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