JP7609059B2 - Packaging container and power storage device including same - Google Patents

Description

The present invention relates to a packaging container and an electricity storage device equipped with the same.

Patent Document 1 discloses a battery in which a battery element is housed in a pouch-shaped container. A valve structure having a check valve is attached to the container in a seal formed along the periphery. This check valve is configured to operate and release gas when the internal pressure of the container rises above a certain level.

JP 2016-31934 A

However, if the electrolyte contained in the container enters the passages within the valve structure, salt, electrolyte components, etc. may precipitate and block the passages, impairing the gas venting function of the valve structure.

The present invention aims to provide a packaging container having a valve structure for venting that can prevent liquid contained therein from entering a passage in the valve structure and impairing its function, and an electricity storage device including the same. Note that the present invention is not limited to the above-mentioned example of an electricity storage device, but can be applied to any packaging container that can block a passage in the valve structure when liquid contained in the packaging container enters the passage.

The packaging container according to a first aspect of the present invention comprises a container body and a valve structure. The container body is made of a packaging material and has a peripheral seal portion that defines the periphery of an internal space. The valve structure is attached to the peripheral seal portion and has a passage that connects the internal space to an external space, and when the pressure of the internal space increases due to gas generated in the internal space, the valve structure releases the gas through the passage. The passage has an inlet facing the internal space and an outlet facing the external space. The container body further has a pattern seal portion including a sealed area and a non-sealed area. The non-sealed area forms a plurality of flow paths that guide the gas generated in the internal space to the inlet. The sealed area defines the wall surfaces of the plurality of flow paths.

A packaging container according to a second aspect of the present invention is a packaging container according to the first aspect, wherein the pattern seal portion is formed at least around the periphery of the entrance.

A packaging container according to a third aspect of the present invention is a packaging container according to the first or second aspect, wherein the pattern seal portion is not in contact with the external space.

A packaging container according to a fourth aspect of the present invention is a packaging container according to any one of the first to third aspects, wherein the pattern seal portion is arranged to surround the entrance.

A packaging container according to a fifth aspect of the present invention is a packaging container according to any one of the first to fourth aspects, wherein the valve structure includes a check valve.

A packaging container according to a sixth aspect of the present invention is a packaging container according to any one of the first aspect to the fifth aspect, wherein the valve structure includes a break valve.

The seventh aspect of the present invention relates to a storage device that is a packaging container according to any one of the first to sixth aspects, wherein the packaging material is composed of a laminate film.

An electricity storage device according to an eighth aspect of the present invention is a packaging container according to any one of the first to seventh aspects, further comprising an adhesive member adhered to an outer surface of the valve structure and to the peripheral seal portion.

The electricity storage device according to the ninth aspect of the present invention comprises a packaging container according to any one of the first to eighth aspects and an electricity storage device element contained in the internal space.

According to the present invention, a packaging container is provided that includes a valve structure for venting. The valve structure is attached to a peripheral seal portion of the container body. The container body has a pattern seal portion including a sealed area and a non-sealed area. The non-sealed area forms a plurality of flow paths, which extend to guide gas generated in the container body to the inlet of the valve structure. The sealed area defines the wall surfaces of these flow paths. The plurality of flow paths formed by such a pattern seal portion have a more complex overall configuration of the flow paths than when a single flow path is formed, which becomes a resistance to the liquid in the container body reaching the inlet of the valve structure. On the other hand, the gas generated in the container body has a higher fluidity than the liquid, so it easily passes through the flow path. Therefore, according to the above configuration, while ensuring the gas venting function of the valve structure, it is possible to suppress the liquid contained in the packaging container from entering the passage in the valve structure and impairing its function.

FIG. 2 is a plan view of an electricity storage device including a packaging container according to one embodiment of the present invention. Cross-sectional view of FIG. FIG. IV-IV cross-sectional view of FIG. 3 . 3B is a cross-sectional view taken along the line VV in FIG. FIG. FIG. 13 is a cross-sectional view of a valve structure according to a modified example. FIG. 13 is a diagram showing a breakaway valve included in a valve structure according to a modified example. FIG. 13 is an enlarged plan view of the periphery of a pattern seal portion according to a modified example. FIG. 13 is an enlarged plan view of the periphery of a pattern seal portion according to another modified example. FIG. 13 is a plan view of an electricity accumulation device showing an arrangement of a pattern seal portion according to a modified example. FIG. 13 is a plan view of an electricity accumulation device showing an arrangement of a pattern seal portion according to another modified example. FIG. 13 is a plan view of an electricity accumulation device showing a pattern seal portion according to still another modified example. FIG. XII-XII cross-sectional view of Figure 11.

Below, with reference to the drawings, we will explain a packaging container and an energy storage device equipped with the same according to one embodiment of the present invention.

<1. Overall configuration of the electricity storage device>
Fig. 1 shows a plan view of an electricity storage device 1 including a packaging container 10 according to this embodiment. Fig. 2 is a cross-sectional view taken along line II-II of Fig. 1. In these figures, for reference, parts that are not normally visible from the outside are partially shown by dotted lines. Hereinafter, for convenience of explanation, unless otherwise specified, the up-down direction in Fig. 1 will be referred to as "front-back", the left-right direction will be referred to as "left-right", and the up-down direction in Fig. 2 will be referred to as "up-down". However, the orientation of the electricity storage device 1 during use is not limited to this.

The packaging container 10 of this embodiment is for use as an electricity storage device, and includes a container body 100, as well as a tab 300 and a tab film 310 attached to the container body 100. The internal space S1 of the container body 100 contains an electricity storage device element 400.

The container body 100 is composed of packaging materials 110 and 120. When viewed from a direction perpendicular to the vertical direction, the packaging materials 110 and 120 are heat-sealed and fused to each other at the outer periphery of the container body 100, thereby forming a peripheral seal portion 130. The peripheral seal portion 130 forms an internal space S1 of the container body 100 that is isolated from the external space. When viewed from a direction perpendicular to the vertical direction, the peripheral seal portion 130 defines the periphery of the internal space S1 of the container body 100. Note that the form of heat sealing referred to here may be heat welding from a heat source, ultrasonic welding, or the like. In any case, the peripheral seal portion 130 refers to the portion where the packaging materials 110 and 120 are fused and integrated.

The packaging materials 110 and 120 are, for example, composed of a resin molded product or a film. The resin molded product referred to here can be manufactured by a method such as injection molding, compressed air molding, vacuum molding, or blow molding, and in-mold molding may be performed to impart design and functionality. The type of resin can be polyolefin, polyester, nylon, ABS, or the like. The film referred to here is, for example, a plastic film or a metal foil that can be manufactured by a method such as an inflation method or a T-die method. The film referred to here may or may not be stretched, and may be a single-layer film or a laminated film. The laminated film referred to here may be manufactured by a coating method, may be a film in which multiple films are bonded together with an adhesive, or may be manufactured by a multi-layer extrusion method.

As described above, the packaging materials 110 and 120 can be configured in various ways, but in this embodiment, they are configured from a laminate film. The laminate film can be a laminate in which a base layer, a barrier layer, and a heat-sealable resin layer are laminated. The base layer functions as a base material for the packaging materials 110 and 120, and is typically a resin layer that forms the outermost layer of the container body 100 and has insulating properties. The barrier layer has the function of preventing water vapor, oxygen, light, etc. from penetrating into the electricity storage device 1 in addition to improving the strength of the packaging materials 110 and 120, and is typically a metal layer made of aluminum or the like. The heat-sealable resin layer is typically made of a heat-sealable resin such as polyolefin, and forms the innermost layer of the container body 100.

The shape of the container body 100 is not particularly limited, and can be, for example, a bag-like (pouch-like) shape. The bag-like shape here can be a three-sided seal type, a four-sided seal type, a pillow type, a gusset type, or the like. However, the container body 100 of this embodiment has a shape as shown in Figures 1 and 2. That is, the container body 100 of this embodiment is manufactured by heat-sealing a packaging material 110 formed into a tray shape and a sheet-like packaging material 120 superimposed thereon along the outer periphery in a plan view. The packaging material 110 includes a square ring-shaped flange portion 114 corresponding to the outer periphery in a plan view, and a molded portion 112 that is continuous with the inner edge of the flange portion 114 and bulges downward from there. The flange portion 114 and the outer periphery of the packaging material 120 facing it in a plan view are heat-sealed so as to be integrated, forming a peripheral seal portion 130. The peripheral seal portion 130 extends around the entire outer periphery of the container body 100 and is formed into a square ring shape. In addition, the packaging material 110 may have the same shape as the packaging material 120 , or the packaging material 120 may have the same shape as the packaging material 110 .

The power storage device element 400 is, for example, a power storage member such as a lithium ion battery (secondary battery) or a capacitor, and contains an electrolyte. When an abnormality occurs in the power storage device element 400, gas may be generated in the internal space S1 of the container body 100. In addition, when the power storage device element 400 is a capacitor, gas may be generated in the internal space S1 of the container body 100 due to a chemical reaction in the capacitor. In addition, either a primary battery or a secondary battery may be contained in the packaging container 10, but preferably a secondary battery is contained. The type of secondary battery contained in the packaging container 10 is not particularly limited, and examples thereof include, in addition to a lithium ion battery, a lithium ion polymer battery, a solid-state battery, a lead acid battery, a nickel-hydrogen battery, a nickel-cadmium battery, a nickel-iron battery, a nickel-zinc battery, a silver oxide-zinc battery, a metal-air battery, a polyvalent cation battery, a capacitor, and the like.

The tabs 300 are metal terminals used for inputting and outputting power in the power storage device element 400. The tabs 300 are arranged separately at the left and right ends of the container body 100, one of which constitutes a positive terminal and the other of which constitutes a negative terminal. One left and right end of each tab 300 is electrically connected to an electrode (positive or negative electrode) of the power storage device element 400 in the internal space S1 of the container body 100, and the other end protrudes outward from the peripheral seal portion 130. The above-mentioned form of the power storage device 1 is particularly preferable for use in electric vehicles such as electric vehicles and hybrid vehicles in which a large number of power storage devices 1 are connected in series and used at high voltage.

The metal material constituting the tab 300 is, for example, aluminum, nickel, copper, etc. When the power storage device element 400 is a lithium ion battery, the tab 300 connected to the positive electrode is typically made of aluminum, etc., and the tab 300 connected to the negative electrode is typically made of copper, nickel, etc.

The left tab 300 is sandwiched between the packaging materials 110 and 120 at the left end of the peripheral seal portion 130 via the tab film 310. The right tab 300 is also sandwiched between the packaging materials 110 and 120 at the right end of the peripheral seal portion 130 via the tab film 310.

The tab film 310 is an adhesive film and is configured to adhere to both the packaging materials 110 and 120 and the tab 300 (metal). By using the tab film 310, the tab 300 and the innermost layer (thermally adhesive resin layer) of the packaging materials 110 and 120 can be fixed together even if they are made of different materials.

When gas is generated in the internal space S1 of the container body 100 as the power storage device 1 operates, the pressure in the internal space S1 gradually rises. If the pressure in the internal space S1 rises excessively, the container body 100 may burst and the power storage device 1 may be destroyed. The packaging container 10 is provided with a valve structure 200 as a mechanism for preventing such an event. The valve structure 200 is a gas vent valve for adjusting the pressure in the internal space S1, and is attached to the peripheral seal portion 130 of the container body 100. In addition, the container body 100 of this embodiment is formed with a pattern seal portion 500 to maintain the gas vent function of the valve structure 200. The configurations of the valve structure 200 and the pattern seal portion 500 will be described in detail below.

2. Configuration of valve structure
Fig. 3 is a plan view of the valve structure 200. Fig. 4 is a cross-sectional view taken along line IV-IV in Fig. 3, and Fig. 5 is a cross-sectional view taken along line V-V in Fig. 3. As shown in Fig. 5, the valve structure 200 of this embodiment is a check valve capable of repeated gas release, and in particular, a ball spring type check valve. The valve structure 200 is a relief valve that switches between an open state and a closed state depending on the pressure in the internal space S1.

3 to 5, the valve structure 200 includes a valve function section 210 and an attachment section 220. The attachment section 220 is a section for attaching the valve structure 200 to the container body 100. The attachment section 220 is fixed to the container body 100 by being heat-sealed while sandwiched between the packaging materials 110 and 120 constituting the peripheral seal section 130 during molding of the container body 100 (see FIG. 2). This heat sealing causes the outer peripheral surface of the attachment section 220 and the packaging materials 110 and 120 to be fused and joined together. In this embodiment, the valve function section 210 is disposed outside the peripheral seal section 130 and is not sandwiched between the packaging materials 110 and 120 (see FIGS. 1 and 2). As a result, the risk of various components constituting the valve function section 210 being destroyed by deformation or the like due to the heat generated when the attachment section 220 is attached to the container body 100 by heat sealing is reduced.

It is preferable that the attachment portion 220 is made of a material that directly adheres to the innermost layer of the packaging materials 110 and 120. For example, the attachment portion 220 can be made of a material that has the same heat-sealing properties as the innermost layer of the packaging materials 110 and 120, such as a resin such as polyolefin. If the attachment portion 220 cannot be made of such a material due to reasons such as heat resistance, the attachment portion 220 can be adhered to both the attachment portion 220 and the innermost layer of the packaging materials 110 and 120 via a film that can adhere to both.

The attachment portion 220 is connected to the valve function portion 210. As shown in FIG. 4, the valve function portion 210 and the attachment portion 220 each have an approximately cylindrical outer shape and are coaxial with each other. Here, the common central axis of both is represented by reference character C1. The central axis C1 extends parallel or approximately parallel in the front-rear direction.

The valve function part 210 and the attachment part 220 are both cylindrical as a whole. The inner space of the valve function part 210 and the inner space of the attachment part 220 are connected to each other, thereby forming a passage L1 inside the valve structure 200. The passage L1 extends along the central axis C1 direction. The passage L1 has an inlet O1 facing the internal space S1 of the container body 100 and an outlet O2 facing the external space. Therefore, when the valve structure 200 is in an open state, the passage L1 connects the internal space S1 to the external space. On the other hand, when the valve structure 200 is in a closed state, the valve structure 200 seals the internal space S1 from the external space. When the pressure in the internal space S1 increases due to gas generated in the internal space S1, the valve structure 200 opens and releases the gas to the external space through the passage L1.

In this embodiment, the valve function portion 210 has a cylindrical body 211, an O-ring 212, a ball 214, and a spring 216. The cylindrical body 211 and the mounting portion 220 can be configured as an integral unit, or can be manufactured as separate parts and then connected. The cylindrical body 211 can be made of a metal such as stainless steel, or a resin such as polyolefin. The cylindrical body 211 defines an internal space as a part of the passage L1, and within the internal space, the O-ring 212, the ball 214, and the spring 216 are arranged in this order toward the outside in the direction of the central axis C1.

The cylinder 211 has a valve seat 211a. The valve seat 211a defines an inverted truncated cone-shaped space that expands toward the external space as a part of the internal space of the cylinder 211. The valve seat 211a receives the ball 214 as a valve body that is biased from the outside by the spring 216, and at this time, the closed state of the valve structure 200 is formed. In the example of FIG. 5, the spring 216 is a coil spring, but is not limited to this and can be, for example, a leaf spring. When the O-ring 212 sits on the valve seat 211a, it eliminates the gap between the ball 214 and the valve seat 211a, and helps to increase the sealing performance in the closed state. The O-ring 212 is a hollow circular ring, and is made of, for example, fluororubber. The material of the ball 214 and the spring 216 is not particularly limited, and for example, both can be made of metal such as stainless steel. The ball 214 may be made of resin or rubber.

The internal space of the mounting part 220 is connected to the internal space S1 of the container body 100. When the pressure in the internal space S1, i.e., the pressure in the internal space of the mounting part 220, reaches a predetermined pressure, the gas led from the internal space S1 presses the ball 214 in the upward direction of FIG. 5. When the ball 214 is pressed and separated from the valve seat 211a, the spring 216 deforms, the ball 214 moves upward, and the open state of the valve structure 200 is formed. In this open state, the gas generated in the internal space S1 flows into the valve function part 210 through the gap formed between the ball 214 and the O-ring 212, and is further discharged to the external space through the outlet O2. In this way, when the gas in the internal space S1 is discharged through the passage L1, the force pressing the ball 214 in the upward direction of FIG. 5 weakens, and the force with which the spring 216 urges the ball 214 in the downward direction of FIG. 5 becomes greater. As a result, the shape of the spring 216 is restored, and the valve structure 200 is again in the closed state.

In the closed state, the valve structure 200 can prevent atmospheric air from entering the internal space S1 of the container body 100. On the other hand, even in the open state, atmospheric air is unlikely to enter the internal space S1. This is because in the open state, the pressure in the internal space S1 is maintained higher than or equal to the pressure in the external space. Therefore, the valve structure 200 can effectively prevent atmospheric air from entering the container body 100 and prevent deterioration of the electricity storage device element 400 due to the moisture contained therein.

3. Configuration of pattern seal portion
As described above, the valve structure 200 is a gas vent valve that adjusts the pressure in the internal space S1 of the container body 100. However, if the liquid (mainly the electrolyte) contained in the internal space S1 enters the passage L1 in the valve structure 200, the gas venting function of the valve structure 200 may be impaired. This is because solids such as salts and electrolyte components precipitated from such liquid may block the passage L1. To prevent the above situation, the container body 100 has a pattern seal portion 500, shown by hatching with diagonal lines in FIG. 1, around the inlet O1 of the valve structure 200.

6 is an enlarged plan view of the periphery of the pattern seal portion 500. In FIG. 6, the heat-sealed sealed area is shown with cross-line hatching. On the other hand, in FIG. 6, the non-sealed area that is not heat-sealed is shown without hatching or filling. In FIG. 6, the dashed dotted line surrounding the pattern seal portion 500 is a reference line and is not actually visible. In addition, the pattern seal portion here does not mean a solid seal portion that is sealed with substantially no gaps, but a region that forms a pattern or design as a whole by combining the seal area and the non-seal area. In addition, the heat-sealed seal area means a portion where the facing packaging materials 110 and 120 are fused and integrated.

6, the pattern seal portion 500 is positioned to cover and surround the inlet O1 of the mounting portion 220 of the valve structure 200. Therefore, gas and liquid in the internal space S1 of the container body 100 cannot reach the inlet O1 of the valve structure 200 without passing through the pattern seal portion 500. Note that in FIG. 6, the dotted line indicates the portion of the mounting portion 220 that is attached to the peripheral seal portion 130.

The non-sealed area 520 included in the pattern seal part 500 forms a plurality of flow paths L2 that extend in a branching manner, and the sealed area 510 included in the pattern seal part 500 defines the wall surfaces of these flow paths L2. These flow paths L2 extend to guide the gas generated in the internal space S1 to the inlet O1. Thus, through these flow paths L2, the passage L1 in the valve structure 200 communicates with the center of the internal space S1 (the space inside the pattern seal part 500, excluding the space in the internal space S1 formed by the flow paths L2).

The sealed area 510 is arranged to branch the flow path L2 formed by the non-sealed area 520. Therefore, compared to the case where the pattern seal portion 500 does not exist and the entire area occupied by it is a non-sealed area, the flow path from the center of the internal space S1 to the inlet O1 is narrowed around the inlet O1 of the valve structure 200. The shape of the flow path L2, which is branched in this way and has a narrowed cross-sectional area (pipe diameter), increases the resistance (piping resistance) of the liquid in the internal space S1 passing through the flow path L2 and reaching the inlet O1 of the valve structure 200. That is, the friction force acting between the wall surface of the flow path L2 defined by the sealed area 510 and the liquid increases, making it difficult for the liquid to enter the pattern seal portion 500. On the other hand, the shape of the flow path L2 as described above can also act as a resistance to the gas generated in the internal space S1 reaching the inlet O1. However, gas generally has a higher fluidity than liquid, so it is easier for gas to pass through the flow path L2 than liquid. Therefore, the pattern seal portion 500 allows sufficient gas permeation while suppressing liquid permeation. As a result, the pattern seal portion 500 can stably guide the gas in the internal space S1 into the passage L1 of the valve structure 200 while suppressing the liquid in the internal space S1 from entering the passage L1 and impairing its function.

6, the pattern seal portion 500 of this embodiment forms a pattern in which elongated seal areas 510 extending in the left-right direction are intermittently arranged. More specifically, a pattern in which elongated seal areas 510 extending in the left-right direction are arranged at intervals in the left-right direction is arranged in a multi-stage configuration in the front-rear direction. The patterns of each stage may be the same or different (the terms "matching" and "difference" used here mean that the patterns overlap when moved in parallel, without taking into account the shift in the left-right direction, and "difference" means that the patterns do not overlap). The seal areas 510 are arranged alternately in adjacent stages. That is, the non-seal area 520 between the seal areas 510 in a certain stage overlaps with the seal area 510 of the adjacent stage based on the left-right direction. As a result, the flow path L2 is bent many times in the pattern seal portion 500, and a larger area of contact is made with the wall surface formed by the seal area 510. Therefore, the pattern seal portion 500 having such a shape can efficiently suppress the permeation of liquid.

6, the peripheral seal portion 130 is a solid seal portion, and together with the mounting portion 220, surrounds the pattern seal portion 500 from the outside. As a result, the pattern seal portion 500 does not contact the external space in a plan view, and gas and liquid in the internal space S1 do not leak directly to the outside from the flow path L2.

4. Modifications
Although one embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and various modifications are possible without departing from the spirit of the present invention. For example, the following modifications are possible. In addition, the gist of the following modifications can be combined as appropriate.

<4-1>
Although the packaging container 10 of the above embodiment is configured for use in an electricity storage device, the use of the packaging container according to the present invention is not limited thereto, and the contents are not particularly limited. The packaging container according to the present invention is excellent for containing contents that generate gas over time and that contain a liquid containing a component that may solidify or otherwise clog the passage if it enters the passage of the valve structure.

<4-2>
The valve structure 200 in the above embodiment is a ball spring type, but is not limited thereto, and may be, for example, a poppet type, a duckbill type, an umbrella type, a diaphragm type, or the like. In addition, the valve body included in the valve structure 200 in the above embodiment is a spherical ball 214, but is not limited to such a shape, and various shapes can be adopted as long as it functions as a valve body. For example, the valve body may be hemispherical, oblong, or oblate. When the valve body is hemispherical, the spherical side may be received by the valve seat 211a, and a columnar member may extend from the center of the flat surface opposite the spherical surface to the opposite side to the spherical surface. In this case, the columnar member may be configured to be received inside the spring 216, thereby stabilizing the position of the valve body in the cylindrical body 211.

In addition, the valve structure 200 in the above embodiment is a check valve capable of repeatedly releasing gas, but it may be a break valve capable of releasing gas only once. In addition, the number of valve mechanisms included in the valve structure 200 is not particularly limited, and for example, the valve structure 200 may include both a check valve and a break valve, may include multiple break valves, or may include multiple check valves.

The rupture valve in this modified example can be configured in various ways. For example, as shown in FIG. 7A, the rupture valve can be configured by a thin plate or film 250 arranged to block the passage L1 in the valve structure 200. This rupture valve (hereinafter, the rupture valve is given the reference symbol 250) can be configured, for example, by attaching a laminate film to the cylindrical body 211 by heat sealing so as to cover the outlet O2. In this example, when the pressure in the internal space S1 of the container body 100 increases, the laminate film, which is the rupture valve 250, peels off to open the valve. In another example, the rupture valve 250 may be a thin metal plate such as aluminum, and as shown in FIG. 7B, the thin plate may have a notch 251 extending radially from the center. The notch 251 does not penetrate the rupture valve 250 in the thickness direction and is formed thinner than other parts. In this case, when the pressure in the internal space S1 of the container body 100 increases, the rupture valve 250 can open by breaking the rupture valve 250 rather than by the rupture valve 250 falling off the cylindrical body 211.

<4-3>
The pattern formed by the pattern seal portion 500 is not limited to those described in the above embodiment. For example, as shown in FIG. 8A, the pattern seal portion 500 may be formed by arranging cross-shaped seal areas 510A at intervals. Also, as shown in FIG. 8B, the pattern seal portion 500 may have only one continuous seal area 510B. In this case, the flow path L2 branches, and the pattern seal portion 500 can suppress the permeation of the liquid. In addition, the seal area included in the pattern seal portion 500 can be any shape, such as a circle, a square, a star, etc.

<4-4>
The arrangement of the pattern seal portion 500 in the container body 100 is not limited to only the vicinity of the inlet O1 of the valve structure 200 as in the above embodiment. For example, as shown in Fig. 9A, the pattern seal portion 500A may be formed at a position adjacent to the peripheral seal portion 130 along the entire inner end circumference of the peripheral seal portion 130. As another example, as shown in Fig. 9B, the pattern seal portion 500B may be formed at a position adjacent to the peripheral seal portion 130 along the entire side of the peripheral seal portion 130 to which the valve structure 200 is attached.

<4-5>
A pattern seal portion 500 as shown in Fig. 10 is also possible. That is, in the above-described embodiments of Fig. 6, Fig. 8A, and Fig. 8B, the branching point of the flow path L2 is located near the inlet O1 of the valve structure 200, but as shown in Fig. 10, the branching point of the flow path L2 formed by discontinuing the seal area 510C may be located at a position away from the periphery of the inlet O1 of the valve structure 200.

<4-6>
In the above embodiment, in order to facilitate fixing of the valve structure 200 to the container body 100 and improve the strength of the fixation, an adhesive member may be interposed between the mounting portion 220 of the valve structure 200 and the peripheral seal portion 130 of the container body 100.

The adhesive member is a member that has adhesiveness to both the mounting portion 220 of the valve structure 200 and the packaging materials 110 and 120 that constitute the peripheral seal portion 130, and can be configured as an adhesive film 600 as shown in Figures 11 and 12, for example. Figure 11 is an enlarged plan view of the periphery of the mounting portion 220 of the valve structure 200, and Figure 12 is a cross-sectional view of line XII-XII. The mounting portion 220 is sandwiched between the packaging materials 110 and 120 via the adhesive film 600. By using the adhesive film 600 in this way, even if the outer surface of the mounting portion 220 and the innermost layer (thermally adhesive resin layer) of the packaging materials 110 and 120 are made of different materials, the two can be firmly fixed together. Note that, in Figure 11, the part of the adhesive film 600 sandwiched between the packaging materials 110 and 120 is not visible, but the position of the part is shown by dotted lines in the figure for reference.

The adhesive film 600, together with the attachment portion 220, is heat-sealed in a state sandwiched between the packaging materials 110 and 120 constituting the peripheral seal portion 130 during molding of the container body 100. This heat sealing fuses and bonds the outer surface of the attachment portion 220 to the innermost layer of the adhesive film 600, and fuses and bonds the innermost layers of the packaging materials 110 and 120 to the outermost layer of the adhesive film 600.

The innermost layer of the adhesive film 600 is preferably made of a material that easily adheres to the mounting portion 220. Similarly, the outermost layer of the adhesive film 600 is preferably made of a material that easily adheres to the innermost layers of the packaging materials 110 and 120. As an example, the adhesive film 600 may be a monolayer film of maleic anhydride modified polypropylene (PPa). However, the adhesive film 600 is preferably a laminated film of a three-layer structure or a three-layer or more structure having a core material between the innermost layer and the outermost layer. In this case, the adhesive film 600 may be, for example, a laminated film of PPa, polyethylene naphthalate (PEN) as a core material, and PPa, or a laminated film of PPa, polypropylene (PP) as a core material, and PPa. In addition, polyester fiber, polyamide fiber, carbon fiber, etc. can also be preferably used as the core material. In addition, in the above example, instead of PPa resin, resins that can be adhered to metals, such as ionomer resin, modified polyethylene, and EVA, can also be applied.

REFERENCE SIGNS LIST 1 Electricity storage device 10 Packaging container 100 Container body 130 Peripheral seal portion 200 Valve structure 400 Electricity storage device element 500, 500A, 500B Pattern seal portion 510, 510A, 510B, 510C Sealed area 520 Non-sealed area L1 Passage L2 Flow path O1 Inlet O2 Outlet S1 Internal space

Claims (8)

a container body formed of facing packaging materials, the container body defining an interior space for containing a battery element including an electrolyte, the container body having a peripheral seal portion defining a periphery of the interior space;
a valve structure including a check valve that is attached so as to be sandwiched between the facing packaging materials at the peripheral seal portion and has a cylindrical structure that forms a passage that connects the internal space to an external space, and that changes from a closed state that blocks the passage to an open state that opens the passage when pressure in the internal space increases due to gas generated in the internal space, and releases the gas through the passage,
the peripheral seal portion is sealed by joining the facing packaging materials to each other and by joining the facing packaging materials to the cylindrical structure,
the passage has an inlet facing the interior space and an outlet facing the exterior space;
The container body further has a pattern seal portion including a sealed area and a non-sealed area,
the non-sealed region forms a plurality of flow paths that guide the gas generated in the internal space to the inlet,
the sealing area defines walls of the plurality of flow channels;
The plurality of flow paths guide the gas generated in the internal space to the inlet, while preventing the electrolyte from reaching the inlet and clogging the passage.
Packaging container. The pattern seal portion is formed at least around the inlet.
The packaging container according to claim 1. The pattern seal portion is not in contact with the external space.
The packaging container according to claim 1 or 2. The pattern seal portion is disposed to surround the inlet.
The packaging container according to any one of claims 1 to 3. the valve structure includes a breakaway valve;
The packaging container according to any one of claims 1 to 4. The packaging material is composed of a laminate film.
The packaging container according to any one of claims 1 to 5. an adhesive member bonded to an outer surface of the valve structure and to the peripheral seal portion;
The packaging container according to any one of claims 1 to 6. A packaging container according to any one of claims 1 to 7,
and an electricity storage device element accommodated in the internal space.