JP4867158B2 - Film exterior power storage device - Google Patents

Description

  The present invention relates to a film-clad power storage device. Specifically, the present invention relates to a moisture permeation preventing means applied to the apparatus.

  From the viewpoint of reducing component costs and reducing weight, a battery (film exterior battery) is manufactured using an exterior film having a high gas and moisture barrier property such as a so-called laminate film as an exterior member (Patent Document 1). In a battery (power storage device) constructed with a film exterior, various measures are taken to prevent moisture and gas from entering the battery through gaps in the film. For example, Patent Document 2 describes a film-clad battery in which moisture permeation from the outer peripheral edge is prevented by providing a waterproof cap member at the outer peripheral edge of the film joint. Patent Document 3 includes a water absorbing material between the film and the terminal when the periphery of the terminal (tab) protruding outside from the electrode body unit accommodated in the film is sealed with an exterior film. A battery is described in which moisture adhesion from the sealing portion is prevented by arranging an adhesive sheet.

  On the other hand, a battery structure in which various forms of reinforcing members (for example, plates) are provided inside the exterior film has been studied for the purpose of improving impact resistance and stabilizing the shape. For example, Patent Document 4 describes a battery characterized in that an impact protection resin plate (reinforcing member) is attached to a projecting portion of an external connection terminal on the end face of a wound electrode body unit. Further, Patent Document 5 discloses a reinforcing member corresponding to the stacking width of the multilayer electrode body unit, to which the external connection terminal electrically connected to the unit is attached, around the electrode body unit. A battery characterized in that it is provided in is described. It is necessary to take measures to prevent moisture from entering even in a film-clad battery equipped with these reinforcing members.

JP-A-6-338304 JP 2004-79434 A JP 2004-39358 A JP 2000-173641 A JP 2004-87432 A

A film-clad battery or other power storage device has, due to its mechanism, a protruding portion that protrudes beyond the exterior film (for example, a positive terminal for external connection that must be partially exposed to the outside of the film for connection, and Negative electrode terminal). For this reason, in this type of battery or other power storage device, it is necessary to consider the moisture barrier property at the portion where the protruding portion protrudes from the exterior film, that is, around the protruding portion (between the protruding portion and the film). Since a typical protrusion is made of a material different from the adhesive surface of the exterior film, it is difficult to bond the protrusion and the exterior film. Therefore, the site | part by which a protrusion part protrudes from an exterior film may be a location where a water | moisture content tends to penetrate | invade inside an apparatus (film).
In response to such demands, the techniques described in Patent Documents 1 and 2 do not consider moisture barrier properties between the protruding portion and the exterior film. Even in the film-clad batteries described in Patent Documents 4 and 5, consideration for moisture barrier properties is insufficient. Moreover, in the film-clad battery described in Patent Document 3, moisture absorption is prevented by placing a water-absorbing sheet between the external connection terminal and the exterior film. Since it is necessary to provide a wide joining portion, there is a difficulty that the entire film-clad battery is bulky.

The present invention has been created to satisfy such a demand, and is a film-clad battery or other power storage device having a protruding portion protruding outward of an exterior film, between the protruding portion and the exterior film. An object of the present invention is to provide a film-clad battery or other power storage device provided with means for preventing moisture from entering .

One film-clad battery or other power storage device provided by the present invention is a film-clad power storage device including at least one electrode body unit having a positive electrode and a negative electrode, and an exterior film covering the electrode body unit. And at least one projecting portion projecting outward from the inside of the exterior film beyond the film, and a flange portion made of a material that does not substantially transmit moisture, the surface direction of the exterior film from the projecting portion And a flange portion provided at a position proximate to the film in a shape projecting over the film. And between the said flange part and the exterior film around the said protrusion part is sealed, It is characterized by the above-mentioned.
In this specification, the “power storage device” refers to a power storage device including one or more power storage elements (typically batteries or capacitors) that can extract predetermined electrical energy, and is not limited to a specific power storage mechanism. A lithium primary battery or other primary battery, a lithium secondary battery or other secondary battery, or a capacitor (physical battery) such as an electric double layer capacitor is a typical example included in the power storage device referred to herein.
In this specification, an “electrode body unit” refers to a structure that includes at least one positive electrode and one negative electrode, and forms the main body of a battery or a capacitor (storage element).

  In a film-clad battery or other power storage device having such a configuration, the protruding portion is provided by providing the flange portion of the above material around a protruding portion (for example, an external connection terminal or an exhaust valve) protruding outward from the outer film. Can be effectively prevented from entering the inside of the apparatus from the periphery (typically between the protrusion and the exterior film).

One preferred embodiment of the film-clad battery or other power storage device disclosed herein is characterized in that the flange portion is integral with the protruding portion.
According to such a configuration, there is no gap between the projecting portion and the flange portion, so that moisture intrusion can be prevented more reliably. In addition, since the protruding portion and the flange portion are integrated, the number of components for constructing the power storage device can be reduced, and the productivity of the power storage device can be improved and the cost can be reduced.

Further, another preferred embodiment of the film-clad battery or other power storage device disclosed herein is a seal capable of adhering to either the flange part or the film between the flange part and the exterior film. It is characterized by comprising a layer.
According to such a configuration, the joint between the flange portion and the exterior film is strengthened, and moisture can be prevented from entering the inside of the power storage device along the flange portion (that is, from the gap between the film and the flange portion surface). .

Further, another preferred embodiment of the film-clad battery or other power storage device disclosed herein is an inward side of the exterior film, close to the flange part, and the surface of the film than the flange part. It further has a reinforcing part protruding in the direction.
In the present specification, the “reinforcing portion” refers to a member or a portion that can protect the flange portion and / or the protruding portion from an impact.
According to such a configuration, it is possible to prevent moisture from entering the inside of the power storage device, and to improve the impact resistance around the protruding portion and / or the flange portion.

Another preferred embodiment of the film-clad battery or other power storage device disclosed herein includes a frame body that accommodates the electrode body unit.
According to this configuration, in addition to the effect of preventing moisture from entering the power storage device, the rigidity of the power storage device is improved. Moreover, when a part of frame body comprises the said reinforcement part, the impact resistance in the circumference | surroundings of a protrusion part and / or a flange part can be improved, without increasing the number of parts.
In the present specification, the “frame body” refers to a member that can physically accommodate one or a plurality of electrode body units having a predetermined shape in the exterior film, and the shape thereof is not particularly limited. The electrode body holding member shaped so as to be visually recognized as a frame, box, or case (housing) can be a typical shape (outer shape) of the frame here.

Preferably, the flange part and the protruding part are arranged in a state of being fixed to a part of the frame. Particularly preferably, the frame body is made of a synthetic resin. And the said flange part is arrange | positioned in the state embedded at the inside of this frame, It is characterized by the above-mentioned.
A frame made of a synthetic resin material is relatively lightweight and has excellent impact resistance (rigidity). In addition, by fixing the flange portion and the protruding portion to the resin frame, the construction (assembly) of the power storage device is facilitated, and the flange portion and the protruding portion can be equipped in a more stable state. .

Further, another preferred embodiment of the film-clad battery or other power storage device disclosed herein is characterized in that the flange portion has a surface subjected to a rough surface treatment as a surface facing the exterior film. .
According to such a configuration, the adhesion between the flange portion and the exterior film or the sealing layer can be further improved. Therefore, it is possible to more effectively prevent moisture from entering from the periphery of the protruding portion into the power storage device.

The film-clad battery or other power storage device provided by the present invention typically includes an external connection terminal electrically connected to the electrode body unit as the protruding portion.
According to the present invention, it is possible to effectively prevent moisture from entering from the periphery of the external connection terminal protruding outside the exterior film.

In addition, the technology disclosed in this specification uses external connection terminals (typically, a positive electrode terminal and a negative electrode terminal) as members constituting the protrusions used in the film-clad battery and other power storage devices disclosed herein. provide. A preferred terminal is a long terminal body and a flange portion made of a material that does not substantially transmit moisture, and is formed integrally with the terminal body in a shape protruding in a direction substantially perpendicular to the longitudinal direction of the terminal body. And a flange portion. By using such a terminal, it is possible to obtain a film-clad power storage device (for example, a lithium secondary battery or other film-clad battery) having the above-described configuration.

Therefore, the technique disclosed in the present specification uses, as another aspect, an external connection terminal provided with the flange portion disclosed herein, or other projecting portion constituting member, and a film exterior type, A battery (for example, a film-clad lithium secondary battery) or other method for producing a film-clad storage battery can be provided.

  Hereinafter, preferred embodiments of the present invention will be described. It should be noted that matters other than matters particularly mentioned in the present specification (for example, shapes and locations of protrusions and flanges) and matters necessary for carrying out the present invention (for example, electrode body units, exterior films, etc. to be used) Selection, a method for constructing the power storage device, etc.) can be grasped as design matters of those skilled in the art based on the prior art in the field. The present invention can be carried out based on the contents disclosed in the present specification and common general technical knowledge in the field.

As long as the film-clad power storage device of the present invention is provided with a projecting portion that protrudes outward from the inside of the power storage device beyond the exterior film, and a flange portion that can prevent moisture intrusion from the periphery of the projected portion. There is no limitation on the type of power storage element included in the manufacturing process or power storage device.
Typical examples to which the present invention is applied include various film-clad batteries using a primary battery or a secondary battery as a storage element. The number of power storage elements (for example, cells constituting a secondary battery) configured in the power storage device is not limited to one. It can be a power storage module in which a plurality of power storage elements are configured by mounting a plurality of electrode body units. For example, a battery module in which a battery (cell) such as a lithium secondary battery is used as a power storage element (single battery) and they are electrically connected in series or in parallel is a film-clad power storage device that can be provided by the present invention. This is a preferred example. In such a module, a total positive electrode terminal and / or a total negative electrode terminal (that is, an external electrode) corresponding to an external connection terminal electrically connected to a plurality of power storage elements to be mounted is a typical example of the protruding portion described here. obtain.
Moreover, the film-clad power storage device of the present invention can have various secondary components in addition to the protruding portion and the flange portion. For example, as a preferable secondary component, there is a reinforcing layer as described above provided in the protruding portion or the flange portion or in the vicinity thereof, or a seal layer that can improve the adhesion between the flange portion and the exterior film. Further, a frame body that can accommodate one or a plurality of electrode body units (regardless of whether or not it constitutes a reinforcing portion) may be a suitable component.

As an exterior film which comprises the film exterior type electrical storage apparatus of this invention, if it comprises the exterior body of this kind of film exterior type electrical storage apparatus (for example, secondary battery), it can use without limitation. For example, a laminate film that is conventionally used as an outer package of a lithium secondary battery or the like can be used.
Preferably, it is composed of an outer surface (protective) layer composed of a high melting point resin (for example, polyethylene terephthalate (PET), polytetrafluoroethylene (PTFE), polyamide (PA) resin) and a metal foil (for example, aluminum, steel). An adhesive layer composed of a barrier layer (a barrier layer that blocks gas and moisture) and a heat-fusible resin (a resin having a relatively low melting point, such as ethylene vinyl acetate, or an olefin resin such as polyethylene or polypropylene). A laminate film having a three-layer structure can be suitably used. Such a three-layer laminated film can be easily bonded (fused) to each other by using an appropriate thermocompression bonding means (for example, a heat press).

The protruding portion of the film-covered power storage device disclosed herein is not particularly limited as long as at least a portion protrudes from the inside of the power storage device to the outside of the exterior film. Typical protrusions include a positive terminal and a negative terminal. These external connection terminals are typically made of metal. For example, in a typical form of a film-clad secondary battery (for example, a lithium secondary battery), the positive electrode terminal is made of aluminum and the negative electrode terminal is made of copper.
In general, a film-clad power storage device (typically a battery using a non-aqueous electrolyte solution) is a gas that adjusts pressure by opening a part of the device (exterior body) when the internal pressure increases. An exhaust valve (pressure relief valve) of various mechanisms is provided as a discharge means. Of these valves, at least a part of the valve protrudes outward from the power storage device is a typical example included in the protruding portion. In particular, an exhaust valve having an outer wall portion formed of a material different from an adhesive surface of an exterior film (for example, a three-layer laminated film as described above) such as metal or ceramics is suitable for applying the present invention. This is a protruding part.

The flange portion according to the present invention is made of a material that is substantially impermeable to moisture, and extends from the protrusion disposed at a predetermined portion to the surface direction of the exterior film around the protrusion (that is, along the exterior film around the protrusion). Thus, the outer shape and size of the flange portion itself may be appropriately different depending on the size and application of the power storage device. A material that can be easily molded is preferable. For example, various metal flanges are preferable. The flange portion made of metal has a high moisture permeation preventing performance and can prevent moisture from entering (permeating) even if it has a thin-walled structure (preferably a metal foil having a thickness of 1 mm or less, for example, 100 μm or less).
The flange portion and the protruding portion may be integral or separate members. In the case of separate bodies, both may be joined by various joining processes (caulking joining, press fitting joining, etc.). From the viewpoint of preventing moisture from entering, it is preferable that the flange portion and the protruding portion are integrated. The flange portion and the protruding portion (that is, the protruding member with the flange portion) can be formed by various integrated molding methods. For example, the flange portion can be formed on a part of a predetermined projecting portion constituting member (for example, a terminal) by a technique such as overhanging. For example, if the protruding member is a metal (for example, aluminum or copper which is a terminal for external connection of a lithium secondary battery), the flange portion is attached to the protruding portion by various forging methods or compression molding methods (for example, setting). The method that can be provided is an easy and reliable method.

As the flange portion provided in the projecting portion of the film-covered power storage device disclosed here, at least a surface that is roughened on the surface facing the exterior film is preferably used. By performing the rough surface processing, a power storage device can be obtained in which the sealing performance between the exterior film and the protruding portion is improved, and moisture intrusion is effectively prevented. Further, the roughened surface of the flange portion is in close contact with secondary components (typically reinforcing portions and seal layers described later) that can be interposed between the exterior film and the flange portion. Can also be improved.
In addition, what is necessary is just to select and apply a conventionally well-known rough surface processing technique suitably according to the material which comprises a flange part as rough surface processing, and a special process is not requested | required in implementation of this invention. For example, when the flange portion is made of a metal material, mechanical roughening processing (for example, shot blasting or air blasting), electrolytic etching (for example, AC electrolytic etching), chemical etching (for example, acidic) General techniques such as satin treatment and alkaline satin treatment) are employed.

In a preferred embodiment of the film-wrapped power storage device disclosed herein, a reinforcing portion is provided in the vicinity of the flange portion. Such a reinforcing portion is not particularly limited as long as it has a shape protruding in the surface direction of the exterior film from the flange portion around the protruding portion. For example, it may be a plate provided in the vicinity of the protruding portion, or may be a part of a frame that houses the electrode body unit.
By providing such a reinforcing portion around the protrusion, it is possible to prevent a strong impact from being applied to the protrusion. Therefore, providing a reinforcing portion at such a site is an effective means for improving the reliability of the power storage device (typically a battery).

The reinforcing part is preferably made of a material that is impact resistant and resistant to a reaction product resulting from the use of an electricity storage element (for example, a battery) or an electrolyte constituting the element. Typically, an insulating material is preferably selected. Synthetic resin materials have a relatively low manufacturing cost and are easy to be molded, so that many of them preferably satisfy the above-described conditions. For these reasons, the synthetic resin can be preferably used as a constituent material of the reinforcing portion.
For example, polyolefin resins such as polyethylene and polypropylene, ethylene-propylene-diene copolymer (EPDM) and the like are preferably selected. Further, PPS (polyphenylene sulfide resin), polyimide resin, polyamideimide resin, fluorine resin, PEEK (polyether ether ketone resin), PES (polyether sulfone resin), or the like may be used. The reinforcing part may be composed of a single resin material selected from these resins, or may be composed of a material in which two or more kinds of resins are mixed.

In addition, the film exterior type power storage device may include a frame body that houses one or more electrode body units. In this case, what is comprised from the synthetic resin material as mentioned above for the reason similar to a reinforcement part is preferable. You may add a submaterial in the range which does not reduce the electrical performance of the electrode body unit (and electrical storage element comprised from this unit) accommodated in a frame. For example, various stabilizers (for example, phenol-based and stearic acid-based thermal stabilizers), metal deactivators (for example, hydrazine-based metal deactivators), impact resistance enhancers (for example, ceramic powder), radical reaction terminators Can be appropriately blended.
Preferably, a part of the frame body constitutes the reinforcing portion. With this configuration, it is not necessary to prepare a reinforcing member constituting member separately from the frame body, and an increase in the number of parts constituting the power storage device and complication of the device can be prevented.

  The reinforcing part or the frame body may be manufactured or molded by a general method selected according to the material, and a special process is not required for carrying out the present invention. For example, when synthetic resin is used as a material, general molding techniques such as injection molding, thermoforming (vacuum molding, compressed air molding), etc., depending on the properties of the material (for example, thermoplastic and thermosetting curing characteristics) Is adopted.

  The positional relationship between the reinforcing portion and the flange portion is not particularly limited. For example, a form in which a part of the projecting part is embedded in the reinforcing part (which may be a part of the frame) together with the flange part or the flange part is given as a preferred example. The reinforcing portion and the flange portion (or the protruding portion with the flange portion) arranged in this manner are appropriate for the combination of the material constituting the reinforcing portion and the material constituting the flange portion (or the protruding portion with the flange portion). A conventionally known method can be selected as appropriate. For example, if the reinforcing part is made of synthetic resin and the flange part is made of metal, the reinforcing part (which may be a frame) and the flange part (or the flange part) in such an arrangement form by an insert molding process or a press-fitting process. And the protruding portion) can be formed integrally.

  Alternatively, as a typical other form of the positional relationship between the reinforcing part and the flange part, there is a form in which the flange part is arranged on the outer surface of the reinforcing part (that is, the surface side facing the adhesive surface of the exterior film). In such a form, it is preferable to further include a seal layer that can easily adhere to the flange portion and the exterior film. By providing such a sealing layer, the exterior film and the flange portion can be firmly joined, and the sealing performance around the protruding portion is further improved. In addition, what is necessary is just to select suitably according to the constituent material of a flange part and an exterior film as a material which comprises a sealing layer, and it is not specifically limited. For example, if the flange portion is made of metal and the adhesive surface of the exterior film is a polyolefin resin, a sealing layer made of a synthetic resin that can be in close contact with any of them can be used. As a specific example, there is a seal layer mainly composed of activated polyolefin having an appropriate functional group introduced by plasma irradiation or the like of activated polypropylene or the like. Or you may form a sealing layer using the commercially available resin tape (for example, the tape made from a polypropylene, the double-sided tape made from a polypropylene) excellent in adhesiveness.

  In the form in which the flange portion is disposed on the outer surface side of the reinforcing portion, the surface of the reinforcing portion overlaps with the surface of the flange portion (that is, the surface facing the exterior film) (that is, forms the same surface), or the flange portion A configuration in which a part of the reinforcing part covers a part of the surface (edge part), in other words, the flange part is arranged so as to be recessed into the reinforcing part, or a part of the reinforcing part is disposed in the flange part together with such an arrangement. The form which has advanced on the surface (at least peripheral edge) is preferable. With such a configuration, it is easy to strongly fix the flange portion to the reinforcing portion. For example, when the reinforcing portion is made of synthetic resin and the flange portion is made of metal, the flange portion and the reinforcing portion having such a form can be formed by an insert molding method or a press-fitting method.

  The electrode body unit mounted on the film-clad battery or other power storage device disclosed herein may be a power storage element component (or a power generation element component) that can store and release predetermined power. There is no particular limitation. Typical power storage elements include various types of primary batteries (eg, lithium primary batteries, manganese batteries), secondary batteries (eg, lithium secondary batteries, nickel metal hydride batteries), or capacitors (eg, electric double layer capacitors). be able to. For example, an electrode body unit formed by winding a sheet-shaped positive electrode and negative electrode together with a separator or an electrode body unit formed by laminating a plurality of sheet-shaped positive electrodes, negative electrodes, and separators, as used in lithium secondary batteries, It is a typical example of the electrode body unit which comprises the film exterior type electrical storage apparatus (film exterior type battery) disclosed here. There is no restriction | limiting in particular in the shape and size of the electrode body unit of a film exterior type electrical storage apparatus, A desired form and size can be taken.

  For example, by adopting a projection with a flange, instead of directly joining an exterior film and a projection (for example, an external connection terminal), the flange and the exterior film are joined, thereby sealing around the projection (sealing) )It can be performed. Thereby, the restriction | limiting of ensuring sealing performance is lose | eliminated, and the shape of a protrusion part main body (for example, terminal for external connection) can be designed freely. For example, an external connection terminal having a wide conduction area (that is, thick) can be employed for a battery or other power storage device aiming at high output.

  Several preferred embodiments of the present invention will be described below as detailed examples with reference to the drawings. It should be noted that the present invention is not intended to be limited to the shapes shown in the following description and related drawings.

<First Example>
In this example, a flat box-shaped film-covered lithium secondary battery is shown as a typical example of a power storage device. FIG. 1 is a side view showing an outline of a film-clad battery 10 according to the present embodiment. FIG. 2 is a front view of the battery 10 in which several protrusions 40, 70, 80 are arranged.

As shown in FIG. 1, a film-clad battery 10 of this example is roughly divided into an exterior film 20 (the above-mentioned three-layer structure laminate film), a frame 30 covered with the film 20, and its frame. An electrode body unit 2 accommodated inside the body 30, a pair of external connection terminals (that is, a positive terminal 40 and a negative terminal 70) and an exhaust valve 80 projecting outward from the film 20 are provided.
The frame 30 according to the present embodiment is made of polypropylene resin, and is formed in a substantially square shape when viewed from the side of the wide area facing the battery 10. A part of the frame body 30 (that is, a portion disposed around the flange portion) constitutes the reinforcing portion 32 according to the present invention. The electrode body unit 2 is held inside the frame 30, but the holding structure itself of the electrode body unit 2 may be the same as that of a conventional lithium secondary battery and does not characterize the present invention. An appropriate electrolyte is injected into the frame body 30 together with the electrode body unit 2. The electrolyte injected here can be used without particular limitation as long as it is conventionally used as an electrolyte for lithium secondary batteries, and does not characterize the present invention. Polymer electrolytes that are typically liquid (eg, non-aqueous electrolytes) or typically gel may be used. For example, a nonaqueous electrolytic solution in which 1 mol / L LiPF ₆ is dissolved as a lithium salt in a mixed solvent of diethyl carbonate (DEC) and ethylene carbonate (EC) (for example, a mixed solvent in which DEC: EC is a mass ratio of 8: 3). Can be preferably used.

The electrode body unit 2 according to the present embodiment is a wound electrode body unit that is produced by laminating a positive electrode sheet (positive electrode) and a negative electrode sheet (negative electrode) (not shown) together with a separator, and further winding. In addition, the structure itself of the electrode body unit 2 does not restrict | limit this invention, What is necessary is just to be comprised using the various materials used conventionally. For example, the positive electrode sheet can be formed by applying a positive electrode active material layer for a lithium secondary battery on a long positive electrode current collector. A metal foil such as an aluminum foil is preferably used for the positive electrode current collector. As the positive electrode active material, one kind or two or more kinds of substances conventionally used in lithium secondary batteries can be used without any particular limitation. Preferable examples include LiMn ₂ O _4, LiCoO _2, LiNiO _{2 and the} like. On the other hand, the negative electrode sheet may be formed by applying a negative electrode active material layer for a lithium secondary battery on a long negative electrode current collector. A metal foil such as a copper foil is preferably used for the negative electrode current collector. As the negative electrode active material, one or two or more kinds of materials conventionally used in lithium secondary batteries can be used without any particular limitation. Preferable examples include carbon-based materials such as graphite carbon and amorphous carbon, lithium-containing transition metal oxides and transition metal nitrides. Suitable separator sheets used between the positive and negative electrode sheets include those made of a porous olefin resin.
Thus, an external connection positive terminal 40 (typically an aluminum terminal) is electrically connected to the positive electrode sheet of the electrode body unit 2, and an external connection negative terminal 70 (typically a terminal made of aluminum). Is a copper terminal) electrically connected.

Next, the protrusion part of a present Example is demonstrated. As shown in FIGS. 1 and 2, the film-clad battery 10 of this embodiment is provided with a pair of external connection terminals, that is, an aluminum positive terminal 40 and a copper negative terminal 70. Furthermore, an exhaust valve 80 made of metal (for example, aluminum, steel, stainless steel) is provided as another protrusion. The projecting portions 40, 70, and 80 have flange portions (that is, the positive terminal flange portion 44, the negative terminal flange portion 74, and the exhaust valve flange portion 84) integrally with the projecting portion bodies 42, 72, and 82, respectively. Is formed. Thereby, the permeation | transmission of the water | moisture content from between the exterior films 24, 26, and 28 and the protrusion parts 40, 70, and 80 in the circumference | surroundings of each protrusion part can be prevented effectively.
The shapes of the flange portions 44, 74, and 84 protruding from the protruding portion are not particularly limited as long as the flange portions 44, 74, and 84 extend in a direction substantially parallel to the exterior film 20 and centered on the protruding portion main bodies 42, 72, and 82. However, the larger the size of the flange portion, the greater the ability to prevent (block) moisture penetration. Typical overhanging shapes include a circle, an ellipse, or a rectangle. In the present embodiment, the positive electrode terminal 50 and the negative electrode terminal 70 are provided with flange portions 44 and 74 extending in a rectangular shape, while the exhaust valve 80 is provided with a circular flange portion 84.

  Hereinafter, the individual protrusions 40, 70, 80 provided in the present embodiment will be described with reference to the drawings. Note that the external connection terminals 40 and 70 have the same configuration except for the constituent materials (the positive electrode terminal 40 is made of aluminum and the negative electrode terminal 70 is made of copper). Is omitted. In addition, the method itself for forming the flange portions 44, 74, 84 on the respective protrusions 40, 70, 80 may select a conventional molding technique and does not particularly characterize the present invention. For example, since the protrusions 40, 70, and 80 are all made of metal in this embodiment, the protrusion main bodies 42, 72, and 82 and the flanges 44, 74, and 84 are formed by a general upsetting process or an overhang forming process. Can be molded integrally.

First, the aspect of the aluminum positive electrode terminal 40 used in the film-clad battery 10 of the present embodiment will be described.
FIG. 3 is a cross-sectional view taken along the line III-III in FIG. 2 and schematically shows a positive electrode terminal 40 according to the present embodiment. The positive terminal 40 includes a long terminal body 42 and a rectangular flange portion 44 that can prevent moisture permeation. The terminal body 42 is electrically connected to the electrode body unit 2 inside the battery. As shown in the figure, the reinforcing portion 32 and the exterior film 20 are provided so as to penetrate (beyond) and protrude outward from the battery. Here, the flange portion 44 integrally formed with the positive electrode terminal 40 is provided in a shape fitted into the surface layer portion of the reinforcing portion 32 which is a part of the frame body 30. As described above, there are various processing methods (for example, insert molding method or press-fit molding method) for the method of installing the positive electrode terminal (including the flange portion 44) 40 on the reinforcing portion 32 (frame body 30). The positive electrode terminal 40 is disposed and fixed at a predetermined portion (reinforcing portion) simultaneously with the molding of the resin frame 30 by molding.

Activated polypropylene (that is, an appropriate functional group is introduced by plasma irradiation or the like) between the flange portion 44 and the exterior film 20 which can be firmly adhered (adhered) to both the flange portion 44 and the exterior film 20 adhesive layer. A sealing layer 4 made of polypropylene) is provided. The flange portion 44 including the seal layer 4 is provided so as to constitute substantially the same plane as the outer surface side (the exterior film 20 side) of the reinforcing portion 32.
In addition, in the vicinity of the film outlet 24 where the positive electrode terminal 40 exceeds the exterior film 20, an insulation treatment is performed so that the metal layer (here, the aluminum layer) included in the exterior film 20 and the terminal body 42 do not come into direct contact. The terminals 40 and 70 are not electrically connected to each other through the metal layer of the exterior film 20. In addition, as one of the insulating treatments, an insulating material (for example, synthetic resin) may be filled between the projecting port 24 of the exterior film and the terminal 40.

Next, the exhaust valve 80 used for the film-clad battery 10 of the present embodiment will be described.
4 is a cross-sectional view taken along the line IV-IV in FIG. 2, and schematically shows the exhaust valve 80 according to the present embodiment. The exhaust valve 80 is a means that can quickly discharge the gas generated by using the battery, and is one of the members that improve the safety of the battery. As shown in the drawing, the exhaust valve 80 shown in this embodiment is roughly a pressure formed by an exhaust pipe 82 and an exhaust port 86, a metal ball (sealing ball) 88, and a coil spring (pressure adjusting spring) 90. It is a relief valve. The exhaust valve 80 is configured such that when the gas pressure inside the battery through the exhaust path 92 exceeds the elastic force of the coil spring 90, the metal ball 88 is pushed up by the pressure and the gas is discharged. Such a configuration itself may be the same as that of a conventional exhaust valve, and does not characterize the present invention.

A disc-shaped flange portion 84 is integrally formed on the outer periphery of the exhaust pipe 82 constituting the exhaust valve main body and in the vicinity of the outlet of the exhaust passage 92 (that is, in the vicinity of the metal ball 88). Between the flange portion 84 and the exterior film 20, there is provided an activated polypropylene sealing layer 4 that can be firmly adhered (adhered) to both the flange portion 84 and the exterior film 20 adhesive layer. The configuration of the seal layer 4 is the same as that of the positive electrode terminal 40 described above.
As shown in the figure, the exhaust valve 80 is provided in a form that penetrates (becomes) the reinforcing portion 32 (frame body 30) and the exterior film 20 and protrudes outward from the battery. Here, the flange portion 84 integrally formed with the exhaust valve 80 is provided in a shape fitted into the surface layer portion of the reinforcing portion 32 which is a part of the frame body 30. As described above, there are various processing methods (for example, an insert molding method and a press-fitting molding method) as a method of installing the exhaust valve (including the flange portion 84) 80 on the reinforcing portion 32 (frame body 30). The exhaust valve 80 is disposed and fixed at a predetermined portion (reinforcing portion 32) simultaneously with the molding of the resin frame 30 by molding.

  On the other hand, the exterior film 20 is formed with projecting ports 24, 26, and 28 corresponding to the projecting portions of these projecting portions (the positive terminal 40, the negative terminal 70, and the exhaust valve 80). Thus, after the protruding portions 40, 70, and 80 are drawn out from the protruding ports 24, 26, and 28, the sealing portions are appropriately bonded (heat-sealed) to be covered with the exterior film 20 as shown in FIG. A film-clad battery 10 is constructed.

  According to the film-clad battery 10 of this embodiment having such a configuration, the moisture intrusion from the projecting ports 24, 26, 28 formed in the exterior film 20 is integrally formed with the projecting portions 40, 70, 80. 74, 84. As a result, the linear water permeation path to the inside (that is, the electrode body unit 2) is cut off from the flange portions 44, 74, and 84, and moisture intrusion into the inside of the battery (for example, the electrode body unit 2 or the electrolyte) is effective. Can be prevented. Therefore, according to the film-clad battery 10 of the present embodiment, the performance of the film-clad battery 10 can be maintained over a long period of time by suppressing the performance degradation due to moisture intrusion. Furthermore, by having the reinforcing portion 32 (frame body 30), deformation of the flange portions 44, 74, 84 and the like due to external impact can be suppressed.

<Other embodiments>
Next, as modified examples (other examples) of the above-described embodiment, some suitable modified examples of the shape of the external connection terminal (here, the positive electrode terminal) and the arrangement form on the frame will be described with reference to the drawings. To do. In addition, since the components other than the shape or installation position of the positive terminal flange portion in the reinforcing portion (frame body) and the shape in the protruding portion of the positive terminal in the reinforcing portion are the same as those in the first embodiment described above, such matters The duplicate description of is omitted. Of course, the modifications described below can be applied to other protrusions (exhaust valves, etc.).

  FIG. 5 to FIG. 7 show modified examples of different forms. In these modified examples, unlike the above embodiments, positive terminals 50 and 60 that are integral with the flange portions 54 and 64 are embedded in the frame 30 (reinforcing portion 32). Various means known in the art can be used as means for arranging the positive terminals 50, 60 and other protrusions in the frame 30 (reinforcing part 32) in such a form, and can be preferably formed by, for example, insert molding.

  In the example shown in FIG. 5, the flange portion 54 formed integrally with the positive terminal body 52 is embedded in the frame (resin base material) 30 at a position that is substantially parallel to the exterior film 20 and close to the film 20. ing. Further, the outer surface (film facing surface) side 54a of the flange portion 54 is subjected to a rough surface processing. Thereby, the adhesion (fixing) strength with the frame 30 can be improved. Further, the adhesive layer of the laminate film 20 and the resin frame 30 (reinforcing portion 32) can be directly and firmly heat-sealed without interposing the sealing layer.

  In the example illustrated in FIG. 6, the vicinity of the protrusion corresponding to the positive electrode terminal 60 includes the frame body 30 (reinforcing portion 32) in which the corrugated shape is processed into the corrugated shape 36, and the corrugated shape corresponding to the corrugated shape 36 has a flange. A portion 64 is formed. By forming such a wave shape in the flange portion 64 and the portion of the frame 30 (reinforcing portion 32) close to the flange portion 64, the surface area of the flange portion 64 can be increased and the film 20 (24) can be formed. Even if moisture enters the resin frame 30 from the gap with the positive electrode terminal 60, the moisture path (that is, the flange portion 64) required for the moisture to enter further inside the frame 30 is provided. It is possible to secure a longer detour route. Accordingly, the flange portion 64 having a moisture permeation preventing ability equivalent to that of a large flange portion having a simple flat plate shape can be formed relatively compactly (without being bulky in the lateral direction).

  In the example shown in FIG. 7, in addition to the form shown in FIG. 5, the frame body 30 (reinforcing portion 32) is further compressed in the vicinity of the protrusion corresponding to the positive electrode terminal 50. As a result, the distance between the film 20 and the flange portion 54 in the compressed portion 38 is reduced, and the crystallinity of the resin constituting the compressed portion 38 is increased. Thus, even if moisture enters the resin frame 30 (38) from the gap between the film 20 and the positive electrode terminal 50, the gap between the polymer molecules constituting the frame 30 (38). It is difficult for water molecules to pass through. Therefore, the moisture permeation preventing ability can be improved. Such high crystallization can be easily performed, for example, by heat-pressing the frame 30 (reinforcing portion 32) from the outer surface side.

  By the way, as shown in FIGS. 5 to 7, in these modified examples, around the positive terminals (projections) 50 and 60, between the positive terminals (projections) 50 and 60 and the exterior film 20, A part 34 of the frame (reinforcing portion 32) is disposed. According to such a configuration, the insulation between the metal layer (typically an aluminum layer) of the exterior film 20 (24) around the positive electrode terminals 50 and 60 and the positive electrode terminals 50 and 60 is separately treated. This can be realized without performing a process.

Specific examples of the present invention have been described in detail above, but these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and changes of the specific examples illustrated above. For example, although the aspect which applied this invention to the secondary battery was demonstrated as an Example, the film-clad type electrical storage apparatus which concerns on this invention is not limited to a lithium secondary battery. For example, since the object of the present invention is to effectively prevent moisture intrusion into the inside of the power storage device (specifically, the power storage element), any power storage element that can use a non-aqueous electrolyte in which water permeation becomes a problem The present invention can be preferably applied also to a power storage device including (for example, a lithium primary battery, an organic power capacitor).
The technical elements described in this specification or the drawings exhibit technical usefulness alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. In addition, the technology exemplified in this specification or the drawings achieves a plurality of objects at the same time, and has technical usefulness by achieving the one object itself.

It is the side view which showed typically the film-clad battery which concerns on one Example of this invention. It is the front view which showed typically the surface with the protrusion part of the film-clad battery shown in FIG. FIG. 3 is a partial cross-sectional view partially showing a cross section taken along line III-III in FIG. 2. FIG. 4 is a partial cross-sectional view partially showing a cross section taken along line IV-IV in FIG. 2. It is sectional drawing which showed typically the shape of the protrusion part which concerns on one Example of this invention. It is sectional drawing which showed typically the shape of the protrusion part which concerns on one Example of this invention. It is sectional drawing which showed typically the shape of the protrusion part which concerns on one Example of this invention.

Explanation of symbols

2 Electrode unit 10 Film exterior power storage device 20 Exterior film 40, 50, 60, 70, 80 Protrusion 44, 54, 64, 74, 84 Flange

Claims (5)

A film exterior type power storage device comprising at least one electrode body unit having a positive electrode and a negative electrode, and an exterior film covering the electrode body unit,
A frame housing the electrode body unit;
At least one protrusion protruding outward from the inside of the exterior film beyond the film;
A flange portion of substantially the material moisture is not transmitted, and a flange portion provided at a position close to the said film from said projecting portion in a shape protruding in the surface direction of the outer film,
The main body portion of the frame is made of synthetic resin, and the flange portion is arranged in a state of being embedded in the frame, and the space between the flange portion and the exterior film around the protruding portion is the frame. A film-clad power storage device, which is sealed through a body .   The power storage device according to claim 1, wherein the flange portion is integral with the protruding portion.   The power storage device according to claim 1, further comprising a seal layer that can be in close contact with both the flange portion and the film between the flange portion and the exterior film. A film exterior type power storage device comprising at least one electrode body unit having a positive electrode and a negative electrode, and an exterior film covering the electrode body unit,
A frame housing the electrode body unit;
At least one protrusion protruding outward from the inside of the exterior film beyond the film;
A flange portion made of a material substantially impermeable to moisture, and having a flange portion provided in a position proximate to the film in a shape protruding from the protruding portion in the surface direction of the exterior film ,
The flange section may have a the outer film and the rough surface processed treated surface as opposed surfaces,
The frame body is close to the flange portion on the inner side of the exterior film, and protrudes in the surface direction of the film from the flange portion, and the flange portion is reinforced.
A film exterior type power storage device , wherein a gap between the flange portion and an exterior film around the protrusion is sealed . Examples protrusion comprising said electrode body unit and electrically connected to the external connection terminal, a power storage device according to any one of claims 1-4.

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