Packaging container and power storage device including same

Abstract

Provided is a packaging container having a valve structure for gas purging, the packaging container being capable of preventing a liquid accommodated therein from intruding a passage inside the valve structure and impairing a function thereof. The packaging container further has a container body. The container body has a peripheral seal part. The valve structure is a gas purging valve that is attached to the peripheral seal part and has a passage causing the inside and outside of the container body to communicate with each other. The container body further has a pattern seal part including a seal region and a non-seal region at least on the periphery of the entrance of the valve structure. The non-seal region forms a plurality of flow passages extending so as to guide gas inside the container body to the entrance of the valve structure. The seal region defines wall surfaces of the plurality of flow passages.

Description

[Technical field]

[0001] The present invention relates to a packaging container and an electricity storage device including the same. [Background technology]

[0002] 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 at a seal formed along the periphery. The check valve is configured to operate and release gas when the internal pressure of the container rises above a certain level. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2016-31934 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, if the electrolyte contained in the container enters the passages in the valve structure, salts, electrolyte components, etc. may precipitate and block the passages, impairing the gas venting function of the valve structure.

[0005] The present invention aims to provide a packaging container having a valve structure for venting, which can prevent a 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 a liquid contained in the packaging container enters the passage. [Means for solving the problem]

[0006] A 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.

[0007] A packaging container according to a second aspect of the present invention is the packaging container according to the first aspect, wherein the pattern seal portion is formed at least around the inlet.

[0008] A packaging container according to a third aspect of the present invention is the packaging container according to the first or second aspect, wherein the pattern seal portion is not in contact with the external space.

[0009] A packaging container according to a fourth aspect of the present invention is the packaging container according to any one of the first aspect to the third aspect, wherein the pattern seal portion is arranged so as to surround the entrance.

[0010] A packaging container according to a fifth aspect of the present invention is the packaging container according to any one of the first aspect to the fourth aspect, wherein the valve structure includes a check valve.

[0011] A packaging container according to a sixth aspect of the present invention is the packaging container according to any one of the first aspect to the fifth aspect, wherein the valve structure includes a breakable valve.

[0012] An electricity storage device according to a seventh aspect of the present invention is a packaging container according to any one of the first aspect to the sixth aspect, wherein the packaging material is made of a laminate film.

[0013] 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.

[0014] An electricity storage device according to a ninth aspect of the present invention comprises the packaging container according to any one of the first to eighth aspects, and an electricity storage device element accommodated in the internal space. Effect of the Invention

[0015] According to the present invention, a packaging container is provided with a valve structure for venting. The valve structure is attached to a peripheral seal portion of a 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. [Brief description of the drawings]

[0016] [Figure 1] FIG. 2 is a plan view of an electricity storage device including a packaging container according to one embodiment of the present invention. [Diagram 2] Cross-sectional view taken along line II-II in FIG. [Diagram 3] FIG. [Figure 4] IV-IV cross-sectional view of FIG. 3. [Diagram 5] VV cross-sectional view of Figure 3. [Figure 6] FIG. [Figure 7A] FIG. 13 is a cross-sectional view of a valve structure according to a modified example. [Figure 7B] FIG. 13 is a diagram showing a breakaway valve included in a valve structure according to a modified example. [Figure 8A] FIG. 13 is an enlarged plan view of the periphery of a pattern seal portion according to a modified example. [Figure 8B] FIG. 13 is an enlarged plan view of the periphery of a pattern seal portion according to another modified example. [Figure 9A] FIG. 13 is a plan view of an electricity accumulation device showing an arrangement of a pattern seal portion according to a modified example. [Figure 9B] FIG. 13 is a plan view of an electricity accumulation device showing an arrangement of a pattern seal portion according to another modified example. [Figure 10] FIG. 13 is a plan view of an electricity accumulation device showing a pattern seal portion according to still another modified example. [Figure 11] FIG. [Figure 12] XII-XII sectional view of Figure 11. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] Hereinafter, a packaging container according to one embodiment of the present invention and an electricity storage device including the same will be described with reference to the drawings.

[0018] <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.

[0019] 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. In the internal space S1 of the container body 100, an electricity storage device element 400 is housed.

[0020] 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 heat seal mode 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 a portion where the packaging materials 110 and 120 are fused and integrated.

[0021] The packaging materials 110 and 120 are composed of, for example, 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 multilayer extrusion method.

[0022] 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, typically forms the outermost layer of the container body 100, and is a resin layer having insulating properties. The barrier layer has a function of preventing water vapor, oxygen, light, and the like 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.

[0023] 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 referred to here may be a three-sided sealed type, a four-sided sealed type, a pillow type, a gusset type, or the like. However, the container body 100 of this embodiment has a shape as shown in Figs. 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 to be integrated, forming a peripheral seal portion 130. The peripheral seal portion 130 extends over the entire outer periphery of the container body 100 and is formed into a square ring shape. It should be noted that the packaging material 110 may have the same shape as the packaging material 120 , and the packaging material 120 may have the same shape as the packaging material 110 .

[0024] 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 housed in the packaging container 10, but preferably a secondary battery is housed. The type of secondary battery housed 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, an 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 oxide-zinc storage battery, a metal-air battery, a polyvalent cation battery, a capacitor, and the like.

[0025] The tabs 300 are metal terminals used for inputting and outputting electric power in the electricity 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 electrode terminal and the other of which constitutes a negative electrode terminal. One left and right end of each tab 300 is electrically connected to an electrode (positive electrode or negative electrode) of the electricity 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-described form of the electricity storage device 1 is particularly preferable for use in electric vehicles such as electric vehicles and hybrid vehicles in which a large number of electricity storage devices 1 are connected in series and used at high voltage.

[0026] 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 or the like, and the tab 300 connected to the negative electrode is typically made of copper, nickel, etc.

[0027] The left tab 300 is sandwiched between the packaging materials 110 and 120 at the left end of the peripheral seal portion 130, with the tab film 310 interposed therebetween. The right tab 300 is also sandwiched between the packaging materials 110 and 120 at the right end of the peripheral seal portion 130, with the tab film 310 interposed therebetween.

[0028] 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 to each other even if they are made of different materials.

[0029] When gas is generated in the internal space S1 of the container body 100 as the electricity storage device 1 operates, the pressure in the internal space S1 gradually increases. If the pressure in the internal space S1 increases excessively, the container body 100 may burst and the electricity storage device 1 may be destroyed. The packaging container 10 includes 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 in order 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.

[0030] <2. Valve structure configuration> 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 VV 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.

[0031] As shown in Figs. 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. When the container body 100 is molded, the attachment section 220 is fixed to the container body 100 by being heat-sealed while being sandwiched between the packaging materials 110 and 120 constituting the peripheral seal section 130 (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 heat generated when the attachment section 220 is attached to the container body 100 by heat sealing is reduced.

[0032] The attachment portion 220 is preferably 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 fusion properties as the innermost layer of the packaging materials 110 and 120, for example, 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 and the innermost layer of the packaging materials 110 and 120 can be adhered to each other via a film that is adhesive to both the attachment portion 220 and the innermost layer of the packaging materials 110 and 120.

[0033] 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 denoted by reference character C1. The central axis C1 extends parallel or approximately parallel in the front-rear direction.

[0034] The valve function portion 210 and the attachment portion 220 are both cylindrical as a whole. The inner space of the valve function portion 210 and the inner space of the attachment portion 220 are in communication with each other, and thus a passage L1 is formed inside the valve structure 200. The passage L1 extends along the central axis C1 direction. The passage L1 has an inlet O1 facing the inner space S1 of the container body 100 and an outlet O2 facing the outer space. Thus, when the valve structure 200 is in an open state, the passage L1 communicates the inner space S1 with the outer space. On the other hand, when the valve structure 200 is in a closed state, the valve structure 200 seals the inner space S1 from the outer space. When the pressure in the inner space S1 increases due to gas generated in the inner space S1, the valve structure 200 opens and releases the gas to the outer space through the passage L1.

[0035] 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 attachment portion 220 can be integrally configured, or can be manufactured as separate parts and then connected. The cylindrical body 211 can be made of, for example, 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 the O-ring 212, the ball 214, and the spring 216 are arranged in this order in the internal space toward the outside in the direction of the central axis C1.

[0036] The cylindrical body 211 has a valve seat 211a. The valve seat 211a defines an inverted truncated cone-shaped space expanding toward the outside space as a part of the internal space of the cylindrical body 211. The valve seat 211a receives a ball 214 as a valve body biased from the outside by a spring 216, and at this time, the closed state of the valve structure 200 is formed. The spring 216 is a coil spring in the example of FIG. 5, but is not limited thereto and can be, for example, a leaf spring. When the O-ring 212 is seated on the valve seat 211a, it eliminates a gap between the ball 214 and the valve seat 211a and helps to improve 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.

[0037] The internal space of the attachment portion 220 communicates with 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 attachment portion 220, reaches a predetermined pressure, the gas guided from the internal space S1 presses the ball 214 upward in 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 portion 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 upward in FIG. 5 weakens, and the force of the spring 216 urging the ball 214 downward in FIG. 5 becomes larger. As a result, the shape of the spring 216 is restored, and the closed state of the valve structure 200 is formed again.

[0038] In the closed state, the valve structure 200 can prevent the atmosphere from entering the internal space S1 of the container body 100. On the other hand, in the open state, the atmosphere is unlikely to enter the internal space S1 either. 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 the atmosphere from entering the container body 100 and prevent deterioration of the electricity storage device element 400 due to moisture contained therein.

[0039] <3. Configuration of pattern seal part> 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, indicated by hatching with diagonal lines in FIG. 1, around the inlet O1 of the valve structure 200.

[0040] FIG. 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 by cross-line hatching. On the other hand, in FIG. 6, the non-sealed area not heat-sealed is shown without hatching or filling. In FIG. 6, the dashed dotted line enclosing 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 substantially sealed without gaps, but a region that forms a pattern or design as a whole by combining a seal region and a non-seal region. In addition, the heat-sealed seal region means a portion where the facing packaging materials 110 and 120 are fused and integrated.

[0041] 6, the pattern seal portion 500 is disposed so as 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. In addition, in FIG. 6, the dotted line indicates the portion of the mounting portion 220 that is attached to the peripheral seal portion 130.

[0042] The non-sealed region 520 included in the pattern seal portion 500 forms a plurality of flow paths L2 extending in a branched manner, and the sealed region 510 included in the pattern seal portion 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 portion 500, excluding the space in the internal space S1 formed by the flow paths L2).

[0043] 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 the pattern seal portion 500 is a non-sealed area, the flow path from the center of the internal space S1 to the inlet O1 of the valve structure 200 is narrowed around the inlet O1. The shape of the flow path L2, which is branched in this way and has a narrow 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.

[0044] As shown in FIG. 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 in each stage may match or differ (match and difference here refer to overlapping patterns when translated without considering deviation in the left-right direction, and non-overlapping patterns are referred to as difference). 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 in the stage adjacent to it 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 areas 510. Therefore, the pattern seal portion 500 having such a shape can efficiently suppress the permeation of liquid.

[0045] 6, the peripheral seal portion 130 is a solid seal portion, and surrounds the pattern seal portion 500 from the outside together with the mounting portion 220. As a result, the pattern seal portion 500 does not contact the external space in a plan view, and the gas and liquid in the internal space S1 do not leak directly to the outside from the flow path L2.

[0046] <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.

[0047] <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 storing contents that generate gas over time and contain liquids that contain components that may solidify or otherwise clog the passages if they enter the passages of the valve structure.

[0048] <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. 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.

[0049] Furthermore, the valve structure 200 in the above embodiment is a check valve capable of repeatedly releasing gas, but it may be a breaker valve capable of releasing gas only once. Furthermore, 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 breaker valve, may include multiple breaker valves, or may include multiple check valves.

[0050] 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 so as 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. As 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 be formed with 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 not by falling off the cylindrical body 211, but by the rupture valve 250 breaking.

[0051] <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 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.

[0052] <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.

[0053] <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 around 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 region 510C may be located at a position away from the periphery of the inlet O1 of the valve structure 200.

[0054] <4-6> In the above embodiment, in order to facilitate fixing of the valve structure 200 to the container body 100 and to 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.

[0055] 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 Figs. 11 and 12, for example. Fig. 11 is an enlarged plan view of the periphery of the mounting portion 220 of the valve structure 200, and Fig. 12 is a cross-sectional view of the mounting portion 220 taken along 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 manner, 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 Fig. 11, the portion of the adhesive film 600 sandwiched between the packaging materials 110 and 120 is not visible, but the position of the portion is indicated by dotted lines in the figure for reference.

[0056] The adhesive film 600, together with the mounting portion 220, is heat-sealed in a state where it is sandwiched between the packaging materials 110 and 120 constituting the peripheral seal portion 130 when the container body 100 is molded. By this heat sealing, the outer surface of the mounting portion 220 and the innermost layer of the adhesive film 600 are fused and joined, and the innermost layers of the packaging materials 110 and 120 and the outermost layer of the adhesive film 600 are fused and joined.

[0057] The innermost layer of the adhesive film 600 is preferably made of a material that easily adheres to the attachment 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 structure or more 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, instead of the PPa resin in the above example, resins that can be adhered to metals, such as ionomer resin, modified polyethylene, and EVA, can also be applied. [Explanation of symbols]

[0058] 1. Energy storage devices 10 Packaging containers 100 Container body 130 Peripheral seal 200 Valve structure 400 Energy storage device element 500, 500A, 500B Pattern seal part 510, 510A, 510B, 510C Seal Area 520 Non-sealed area L1 aisle L2 flow path O1 Entrance O2 exit S1 interior space

Claims

1. 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, has a cylindrical structure that forms a passage that connects the internal space to an external space, and when pressure in the internal space increases due to gas generated in the internal space, changes from a closed state that blocks the passage to an open state that opens the passage, and releases the gas through the passage; Equipped with 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.

2. The pattern seal portion is formed at least around the inlet. The packaging container according to claim 1.

3. The pattern seal portion is not in contact with the external space. The packaging container according to claim 1 or 2.

4. The pattern seal portion is disposed to surround the inlet. The packaging container according to any one of claims 1 to 3.

5. the valve structure includes a breakaway valve; The packaging container according to any one of claims 1 to 4.

6. The packaging material is composed of a laminate film. The packaging container according to any one of claims 1 to 5.

7. an adhesive member bonded to the outer surface of the valve structure and to the peripheral seal portion; Further comprising: The packaging container according to any one of claims 1 to 6.

8. A packaging container according to any one of claims 1 to 7, an electricity storage device element accommodated in the internal space; The power storage device comprises:

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