JP6558810B2 - Electrochemical cell and method for producing electrochemical cell - Google Patents

Description

  The present invention relates to an electrochemical cell and a method for producing the electrochemical cell.

  Electrochemical cells such as non-aqueous electrolyte secondary batteries and electric double layer capacitors are used as power sources for various devices. As this type of electrochemical cell, a so-called laminate type electrochemical cell is known in which a laminate film is used for an exterior body that covers an electrode body. The laminate film includes, for example, a metal layer and a resin layer that covers the metal layer.

  In order to seal the electrode body with the laminate film, the electrode body is covered with the laminate film, and then the resin layers located in the superposed portion of the laminate film that are overlapped around the electrode body are welded together.

However, in the laminate type electrochemical cell, there is a possibility that the resin melted at the time of welding flows into the exterior body. When the resin that has flowed into the exterior body comes into contact with the electrode body, it causes a decrease in the reliability of the electrochemical cell.
Therefore, for example, in Patent Document 1 below, the distance between the welded portion (polymerized portion) of the exterior body and the electrode body is set to a length (seal margin) that prevents the molten resin from contacting the electrode body at the time of welding. The structure to perform is disclosed.

JP-T-2006-506602

  However, when actually manufacturing a laminate-type electrochemical cell, it melts within the above-mentioned seal margin due to manufacturing errors (for example, variations in pressure, heat source position, heat conduction, etc.) that occur during welding. It is difficult to fasten the resin.

  An object of the present invention is to provide a highly reliable electrochemical cell and a method for producing an electrochemical cell, which can easily suppress the molten resin from contacting the electrode body during welding.

To achieve the above object, an electrochemical cell according to an aspect of the present invention includes a first member and a second member formed of a laminate material including an electrode body, a metal layer, and a resin layer covering the metal layer. An exterior body that seals the electrode body, wherein the exterior body includes a housing portion that houses the electrode body by the first member and the second member, and the first member and the first member. Two members are overlapped with each other, and a superposition part surrounding the periphery of the accommodating part, and the superposition part is a weld part in which the resin layers of the first member and the second member are ultrasonically welded, and A non-welded portion that is alternately arranged with welded portions, and the resin layers of the first member and the second member are not welded to each other, and the innermost end portion in the overlapping portion is formed by the non-welded portion. Is configured .
An electrochemical cell manufacturing method according to an aspect of the present invention includes an electrode in which an electrode body is disposed between a first member and a second member formed of a laminate material including a metal layer and a resin layer covering the metal layer. A body setting step and a welding step of superposing the portions of the first member and the second member located around the electrode body on each other and performing ultrasonic welding, wherein in the welding step, By welding the resin layers of one member and the second member at intervals, a welded portion in which the resin layers of the first member and the second member are welded, and the first member and A superposed portion having a non-welded portion in which the resin layers of the second member are not welded is formed, and in the welding step, the innermost end portion in the superposed portion is defined as the non-welded portion .

According to this aspect, since the non-welded portion exists in the polymerization portion, the flow of the resin melted at the time of welding to the housing portion can be blocked by the non-welded portion.
Further, in the non-welded portion, the opposing surfaces of the resin layers of the first member and the second member are in close contact with each other without being welded, so that the non-welded portion functions as a spacer that defines the thickness of the welded portion. Therefore, it can suppress that a superposition | polymerization part is crushed at the time of welding, and can suppress that the molten resin spreads out to a storage part.
And since the superposition | polymerization part has a non-welding part, compared with the case where the whole superposition | polymerization part is welded, the quantity of resin fuse | melted at the time of welding can be reduced. Also by this, it can suppress that the resin fuse | melted at the time of welding flows toward an accommodating part.
Thus, in this aspect, since the flow amount of the resin flowing toward the housing portion itself can be reduced, it is possible to easily suppress the molten resin from contacting the electrode body while reducing the influence of manufacturing errors. Thereby, a highly reliable electrochemical cell can be provided.

The electrochemical cell which concerns on 1 aspect of this invention WHEREIN: Any of the said welding parts among the said welding parts may be continued over the perimeter of the circumferential direction around the said accommodating part.
According to this aspect, since the welded portion is continuous over the entire circumference in the circumferential direction, it is possible to suppress communication between the inside and outside of the housing portion through the non-welded portion. Therefore, it is possible to secure the sealing property of the overlapping portion and improve the reliability of the electrochemical cell.

The electrochemical cell which concerns on 1 aspect of this invention WHEREIN: The said welding part and the said non-welding part may be alternately arrange | positioned over the whole superposition | polymerization part.
According to this aspect, since the welding part and the non-welding part are arranged over the whole superposition | polymerization part, it can suppress that resin flows into the accommodating part from the perimeter of a superposition | polymerization part at the time of welding .

  According to one embodiment of the present invention, it is possible to easily prevent the resin melted during welding from coming into contact with the electrode body, and to provide a highly reliable electrochemical cell.

1 is a perspective view of a secondary battery according to an embodiment. 1 is a perspective view of a secondary battery according to an embodiment. It is sectional drawing which follows the III-III line of FIG. It is an expanded sectional view equivalent to the IV-IV line of FIG. It is a schematic plan view of a superposition | polymerization part. It is process drawing explaining the manufacturing method of the secondary battery which concerns on embodiment. It is process drawing explaining the manufacturing method of the secondary battery which concerns on the 1st modification of embodiment. It is a schematic plan view corresponding to FIG. 5 which concerns on the 2nd modification of embodiment. It is a schematic plan view corresponding to FIG. 5 which concerns on the 2nd modification of embodiment. It is a schematic plan view corresponding to FIG. 5 which concerns on the 2nd modification of embodiment. It is a schematic plan view corresponding to FIG. 5 which concerns on the 2nd modification of embodiment. It is a perspective view of the secondary battery which concerns on the other structure of embodiment.

  Hereinafter, embodiments according to the present invention will be described with reference to the drawings. In the following description, a lithium ion secondary battery (hereinafter simply referred to as “secondary battery”), which is a kind of nonaqueous electrolyte secondary battery, will be described as an example of the electrochemical cell according to the present invention. . In the drawings used in the following description, the scale of each member is appropriately changed to make each member a recognizable size.

[Secondary battery]
1 and 2 are perspective views of a secondary battery 1 according to the embodiment.
As shown in FIGS. 1 and 2, the secondary battery 1 of the present embodiment is a so-called button type. The secondary battery 1 mainly includes an electrode body 2 (see FIG. 3), an exterior body 3 that seals the electrode body 2, and an electrolyte solution (not shown) accommodated in the exterior body 3. .

<Electrode body>
3 is a cross-sectional view taken along line III-III in FIG.
As shown in FIG. 3, the electrode body 2 is a so-called laminated type in which a negative electrode 5 and a positive electrode 6 are laminated with a separator (not shown) interposed therebetween. The electrode body 2 of this embodiment is laminated | stacked alternately by bending the negative electrode 5 and the positive electrode 6 from the direction which mutually cross | intersects. In the electrode body 2, the surface facing the first side in the stacking direction (uppermost layer in FIG. 3) is constituted by the positive electrode 6, and the surface facing the second side in the stacking direction (lowermost layer in FIG. 3) is formed by the negative electrode 5. It is configured.

  The electrode body 2 has a circular shape in plan view as viewed from the stacking direction. In the present embodiment, an axis extending through the center of the electrode body 2 and along the stacking direction is a central axis O in plan view. In the following description, a direction along the central axis O may be referred to as an axial direction, a direction orthogonal to the central axis O may be referred to as a radial direction, and a direction of circling around the central axis O may be referred to as a circumferential direction. However, the planar view outer shape of the electrode body 2 is not limited to a circular shape, and can be appropriately changed to a rectangular shape or the like.

  The type of the electrode body 2 can be changed as appropriate. For example, the electrode body 2 may be a laminated type other than a zigzag fold, or may be a wound type or a pellet type. The wound electrode body is obtained by winding a negative electrode and a positive electrode with a separator interposed therebetween. The pellet-type electrode body includes a negative electrode and a positive electrode on both sides of a separator.

<Exterior body>
FIG. 4 is an enlarged cross-sectional view corresponding to the line IV-IV in FIG.
As shown in FIG. 4, the exterior body 3 is configured by two laminated films (first sheet 10 and second sheet 11) being overlapped in the axial direction with the electrode body 2 interposed therebetween. The first sheet 10 includes a metal layer 21 and an inner resin layer 22 and an outer resin layer 23 laminated on both sides of the metal layer 21.

The metal layer 21 is formed of a metal material that blocks outside air and water vapor, such as stainless steel and aluminum.
The inner resin layer 22 constitutes the inner surface of the exterior body 3 when the sheets 10 and 11 are overlapped. The inner resin layer 22 is formed using a thermoplastic resin such as polyolefin polyethylene or polypropylene, for example. Examples of polyolefins include high pressure method low density polyethylene (LDPE), low pressure method high density polyethylene (HDPE), inflation polypropylene (IPP) film, unstretched polypropylene (CPP) film, biaxially stretched polypropylene (OPP) film, linear Any material of short chain branched polyethylene (L-LDPE, metallocene catalyst specification) can be used. Polypropylene resin is particularly preferable.
The outer resin layer 23 constitutes the outer surface of the exterior body 3 when the sheets 10 and 11 are overlapped. The outer resin layer 23 is formed using, for example, the above-described polyolefin, polyester such as polyethylene terephthalate, nylon, or the like. The inner resin layer 22 and the outer resin layer 23 are respectively bonded (thermal welding, adhesive, etc.) to the metal layer 21 via a bonding layer (not shown).

  As shown in FIGS. 1 and 3, the first sheet 10 covers the electrode body 2 from the first side in the axial direction. The first sheet 10 has a cylindrical portion 31 with a top and a protruding portion 32. In the top wall portion 31a of the cylindrical portion 31, a first through hole 33 that penetrates the top wall portion 31a in the axial direction is formed at a central portion in the radial direction.

  As shown in FIG. 3, the 1st drawer | drawing-out part 38 is heat-welded through the 1st sealant ring 37 to the inner surface of the top wall part 31a. The first sealant ring 37 is a sealant film formed in a ring shape. The sealant film is formed of a thermoplastic resin such as polyolefin polyethylene or polypropylene. In the illustrated example, the inner diameter of the first sealant ring 37 is smaller than the outer diameter of the first through hole 33.

  The first lead portion 38 is made of aluminum, for example. The inner surface of the first lead portion 38 (the surface facing the second side in the axial direction) is connected to the positive electrode 6 of the electrode body 2. A positive electrode terminal 39 is disposed (for example, welded or the like) on the outer surface of the first lead portion 38 (the surface facing the first side in the axial direction). The positive terminal 39 is made of nickel or the like. The positive terminal 39 is exposed to the outside of the exterior body 3 through the first sealant ring 37 and the first through hole 33.

  The overhanging portion 32 protrudes outward in the radial direction from the second side end edge in the axial direction on the peripheral wall portion 31 b of the cylindrical portion 31. The overhang portion 32 is formed in a ring shape surrounding the cylinder portion 31 over the entire circumference.

  As shown in FIG. 4, the second sheet 11 includes a metal layer 41 and an inner resin layer 42 and an outer resin layer 43 that are laminated on both sides of the metal layer 41. The configuration, material, and the like of the second sheet 11 are the same as those of the first sheet 10.

As shown in FIGS. 2 and 3, the second sheet 11 is formed in a disk shape having a planar view outer shape formed in the same manner as the first sheet 10. Specifically, the second sheet 11 has a lid portion 45 and an overhang portion 46.
The lid part 45 covers the opening part of the cylinder part 31 described above from the second side in the axial direction. A second through hole 48 penetrating the lid 45 in the axial direction is formed at a central portion in the radial direction of the lid 45.

A second lead portion 52 is connected to the inner surface of the lid portion 45 via a second sealant ring 51 (for example, heat welding). The second sealant ring 51 has the same configuration as the first sealant ring 37.
The second lead portion 52 is made of, for example, copper. The inner surface (the surface facing the first side in the axial direction) of the second lead portion 52 is connected to the negative electrode 5 of the electrode body 2. A negative electrode terminal 55 is disposed (for example, welded or the like) on the outer surface (the surface facing the second side in the axial direction) of the second lead portion 52. The negative terminal 55 is made of nickel or the like. The negative electrode terminal 55 is exposed to the outside of the exterior body 3 through the inside of the second sealant ring 51 and the second through hole 48.

In the exterior body 3 of the present embodiment, a portion defined by the cylindrical portion 31 of the first sheet 10 and the lid portion 45 of the second sheet 11 constitutes a housing portion 58 that houses the electrode body 2. The container 58 is filled with an electrolyte solution.
The overhanging portion 32 of the first sheet 10 and the overhanging portion 46 of the second sheet 11 constitute an overlapping portion 59 that is overlapped around the accommodating portion 58. In the present embodiment, the configuration in which the terminals 39 and 55 are exposed through the through holes 33 and 48 of the sheets 10 and 11 has been described, but the configuration is not limited thereto. For example, in the overlapping portion 59, the terminal may be drawn outside in the radial direction through between the first sheet 10 and the second sheet 11.

<Polymerization part>
Here, as shown in FIG. 4, the exterior body 3 of this embodiment seals the electrode body 2 by welding a part of the inner resin layers 22 and 42 to each other in the overlapping portion 59. Specifically, in the superposition part 59, the welding part S1 in which the inner resin layers 22 and 42 are welded to each other, and the non-welding part S2 in which the inner resin layers 22 and 42 are not welded to each other are alternately (inner resin layer 22, 42 in the in-plane direction of 42).

FIG. 5 is a schematic plan view of the overlapping portion 59.
As shown in FIGS. 4 and 5, the welded portion S <b> 1 extends, for example, in an annular shape over the entire circumference of the overlapping portion 59. A plurality of welded portions S1 are arranged at intervals in the radial direction. In addition, at least one welding part S1 should just be formed in cyclic | annular form.

  The non-welded portion S2 is located on both sides in the radial direction with respect to the welded portion S1. That is, the non-welded portion S2 extends in a ring shape over the entire circumference of the overlapping portion 59, and a plurality of non-welded portions S2 are arranged at intervals in the radial direction. In the non-welded portion S2, the facing surfaces of the inner resin layers 22 and 42 facing each other in the sheets 10 and 11 are in close contact with each other. Therefore, the non-welded portion S2 functions as a spacer that defines the distance between the metal layers 21 and 41 of the sheets 10 and 11 (the thickness in the axial direction of the welded portion S1) in the overlapping portion 59.

  In the illustrated example, the radially innermost end portion in the overlapping portion 59 is formed by the non-welded portion S2. However, the radially innermost end in the overlapping portion 59 may be formed by the welded portion S1. In the present embodiment, the radial widths of the welded portion S1 and the non-welded portion S2 are equal. However, the widths of the welded portion S1 and the non-welded portion S2 can be appropriately changed within a range in which the sealing property of the overlapping portion 59 can be secured.

[Method for producing secondary battery]
Next, a method for manufacturing the secondary battery 1 described above will be described. In the following description, the sealing process of the electrode body 2 will be mainly described.
In the present embodiment, first, the electrode body 2 is disposed between the first sheet 10 and the second sheet 11 (electrode body setting step). Thereby, the electrode body 2 is accommodated in the accommodating portion 58.

FIG. 6 is a process diagram illustrating a method for manufacturing the secondary battery 1.
As shown in FIG. 6, the inner resin layers 22 and 42 of the sheets 10 and 11 are welded to each other in the overlapping portion 59 in a state where the electrolytic solution is filled in the accommodating portion 58 (welding step). In the present embodiment, the inner resin layers 22 and 42 of the overlapping portion 59 are welded at intervals with each other by ultrasonic welding.

  In the welding step, the jig 80 (horn) is pressed from both sides in the axial direction against the overlapping portion 59, and ultrasonic vibration is applied to the overlapping portion 59 while pressing the overlapping portion 59 in the axial direction. In the present embodiment, the surface of the jig 80 (the pressing surface against the overlapping portion 59) is formed with a convex portion 80a and a concave portion 80b by knurling or the like. Therefore, the jig 80 is in contact with the overlapping portion 59 (the outer resin layers 23 and 43) at the convex portion 80a and is separated from the overlapping portion 59 at the concave portion 80b. Accordingly, the ultrasonic vibration is positively transmitted to the overlapping portion 59 through the convex portion 80a. In addition, the convex part 80a is formed in the position corresponding to the welding part S1 mentioned above, and the recessed part 80b is formed in the position corresponding to the non-welding part S2 mentioned above.

In the welding step, portions of the inner resin layers 22 and 42 located in the overlapping portion 59 where ultrasonic vibrations are effectively applied (portions overlapping the convex portions 80a when viewed from the axial direction) are melted. Thereby, the inner side resin layers 22 and 42 of each sheet | seat 10 and 11 are welded. On the other hand, in the inner resin layers 22 and 42 located in the overlapping portion 59, portions where ultrasonic vibration is difficult to be transmitted (portions that overlap with the recess 80b when viewed from the axial direction) are not melted. Therefore, the inner resin layers 22 and 42 of the sheets 10 and 11 maintain a state in which the opposing surfaces are in close contact with each other.
Then, the secondary battery 1 of this embodiment is completed through chemical conversion treatment, deaeration, and the like.

In this embodiment, in the superposition | polymerization part 59, it was set as the structure by which the welding part S1 and the non-welding part S2 are alternately arranged.
According to this structure, in the superposition | polymerization part 59, the flow to the accommodating part 58 of the resin fuse | melted at the time of welding can be obstruct | occluded by the non-welding part S2 because the non-welding part S2 exists.
Further, in the non-welded portion S2, the opposing surfaces of the inner resin layers 22 and 42 of the sheets 10 and 11 are in close contact with each other without being welded, so that the non-welded portion S2 defines the thickness in the axial direction of the welded portion S1. Functions as a spacer. Therefore, it can suppress that welding part S1 is crushed at the time of welding, and can suppress that the molten resin wets and spreads to the accommodating part 58. FIG.
And since the superposition | polymerization part 59 has the non-welding part S2, the quantity of resin fuse | melted at the time of welding can be reduced compared with the case where the superposition | polymerization part 59 whole is welded. Also by this, it can suppress that the resin fuse | melted at the time of welding flows toward the accommodating part 58. FIG.

  Thus, in this embodiment, since the flow amount of the resin flowing toward the housing portion 58 can be reduced, it is easy to make the molten resin come into contact with the electrode body 2 while reducing the influence of manufacturing errors. Can be suppressed. Thereby, the reliable secondary battery 1 can be provided.

  In the present embodiment, since the welded portion S1 is continuously formed over the entire circumference in the circumferential direction, the inside and outside of the housing portion 58 communicate with each other through the nonwelded portion S2 (the nonwelded portion S2 is the diameter of the overlapping portion 59). Can be suppressed over the entire length in the direction). Therefore, the sealing property of the overlapping portion 59 can be secured and the reliability of the secondary battery 1 can be improved.

  In this embodiment, since the welding part S1 and the non-welding part S2 are arranged over the whole superposition | polymerization part 59, it can suppress that resin flows into the accommodating part 58 from the whole superposition | polymerization part 59 at the time of welding.

  In the above-described embodiment, the configuration in which the welded portion S1 and the non-welded portion S2 are arranged over the entire circumference of the overlapping portion 59 has been described, but the configuration is not limited thereto. The welding process may be divided into a first welding process in which only a part in the circumferential direction of the overlapping portion 59 is opened and a second welding process in which the opening is closed. In this case, for example, the heater welding may be performed in the first welding process, and the ultrasonic welding described above may be performed in the second welding process. Thereby, the electrolytic solution can be filled into the accommodating portion 58 through the opening of the overlapping portion 59 between the first welding step and the second welding step. And in a 2nd welding process, it can suppress that the electrolyte solution with which the accommodating part 58 was filled is volatilized by performing the ultrasonic welding mentioned above.

(First modification)
In the above-described embodiment, the configuration in which the welding process is performed by ultrasonic welding has been described. However, the configuration is not limited to this configuration. For example, the welded part S1 and the non-welded part S2 may be formed by heater welding. In this case, in the inner resin layers 22 and 42 located in the overlapping portion 59, portions where the heat of the heater is effectively applied (portions overlapping the convex portions 80a when viewed from the axial direction) are melted. Thereby, the inner side resin layers 22 and 42 of each sheet | seat 10 and 11 are welded. On the other hand, in the inner resin layers 22 and 42 located in the overlapping portion 59, portions where the heat of the heater is difficult to be transmitted (portions overlapping the recess 80b when viewed from the axial direction) are not melted.

  As in the jig 100 shown in FIG. 7, the heat insulating member 101 may be disposed in the recess 80b. In this case, since the pressing surface of the jig 100 against the overlapping portion 59 is formed as a flat surface, the overlapping portion 59 can be stably supported (pressurized). In the configuration shown in FIG. 7, among the inner resin layers 22 and 42 located in the overlapping portion 59, the inner resin layers 22 and 42 are not welded to each other because the heat of the heater is difficult to be transmitted around the heat insulating member 101.

(Second modification)
In the above-described embodiment, the configuration in which the welded portion S1 and the non-welded portion S2 continuously extend in the circumferential direction has been described, but the configuration is not limited thereto.
For example, as shown in FIG. 8, the structure by which the welding part S1 and non-welding part S2 which extend in a radial direction are alternately arranged in the circumferential direction may be sufficient.
As shown in FIGS. 9-11, the structure by which the welding part S1 and the non-welding part S2 are alternately arranged by the circumferential direction and radial direction may be sufficient.

(Third Modification)
In the above-described embodiment, the configuration in which the overlapping portion 59 projects in the radial direction has been described. However, the configuration is not limited to this configuration. For example, as shown in FIG. 12, the overlapping portion 59 may be bent in the axial direction starting from the boundary portion with the accommodating portion 58. In this case, since the accommodating portion 58 overlap each other seen (the peripheral wall portion 31b) and the polymerization unit 59 Toga径direction or al, it is possible to reduce the size of the plan view outline of the rechargeable battery 1. When the overlapping portion 59 is bent, either the welded portion S1 or the non-welded portion S2 may be used as a starting point for bending.

(Other variations)
The preferred embodiments of the present invention have been described above, but the present invention is not limited to these embodiments. Additions, omissions, substitutions, and other modifications can be made without departing from the spirit of the present invention. The present invention is not limited by the above description, but only by the appended claims.

For example, in the above-described embodiment, the secondary battery 1 is described as an example of the electrochemical cell, but a capacitor or a primary battery may be used.
In the above-described embodiment, the configuration in which the first sheet 10 and the second sheet 11 are separated has been described. However, the configuration is not limited to this configuration. A single laminate film may be bent to form the first sheet 10 (first member) and the second sheet 11 (second member).
In the above-described embodiment, the configuration in which a plurality of welded portions S1 and non-welded portions S2 having the same shape are arranged has been described. However, the present invention is not limited to this configuration. The welded part S1 and the non-welded part S1 may have different shapes, and the welded parts S1 (or the non-welded parts S2) may have different shapes.
In the above-described embodiment, the configuration in which the first sheet 10 is formed in a top tube shape has been described. However, the configuration is not limited to this configuration. The accommodating portion 58 may be formed by overlapping the top-like cylindrical first sheet 10 and the bottomed cylindrical second sheet 11.

  In addition, in the range which does not deviate from the meaning of this invention, it is possible to replace suitably the component in the embodiment mentioned above by a known component, and you may combine each modification mentioned above suitably.

1 ... Secondary battery (electrochemical cell)
2 ... Electrode body 3 ... Exterior body 10 ... First sheet (first member)
11 ... 2nd sheet | seat (2nd member)
21 ... Metal layer 22 ... Inside resin layer (resin layer)
23 ... Outer resin layer (resin layer)
42 ... Inner resin layer (resin layer)
43 ... Outer resin layer (resin layer)
58 ... Accommodating part 59 ... Superposition part S1 ... Welding part S2 ... Non welding part

Claims (4)

An electrode body;
A first member and a second member formed of a laminate material including a metal layer and a resin layer covering the metal layer, and an exterior body that seals the electrode body,
The exterior body is
An accommodating portion for accommodating the electrode body by the first member and the second member;
The first member and the second member are overlapped, and the overlapping portion surrounding the periphery of the accommodating portion, and
The overlapping portion is
A welded portion in which the resin layers of the first member and the second member are ultrasonically welded to each other;
A non-welded portion that is alternately arranged with the welded portions and is not welded to the resin layers of the first member and the second member ;
An innermost end portion in the superposed portion is an electrochemical cell constituted by the non-welded portion .   2. The electrochemical cell according to claim 1, wherein any one of the welded portions is continuous over the entire circumference in the circumferential direction around the housing portion.   The electrochemical cell according to claim 1 or 2, wherein the welded portion and the non-welded portion are alternately arranged over the entire superposed portion. An electrode body setting step of disposing an electrode body between a first member and a second member formed of a laminate material including a metal layer and a resin layer covering the metal layer;
A welding step of overlapping and welding the portions located around the electrode body of the first member and the second member,
In the welding step, the resin layers of the first member and the second member were welded to each other by ultrasonically welding the resin layers of the first member and the second member with a gap therebetween . Forming a welded portion, and a superposed portion having a non-welded portion in which the resin layers of the first member and the second member are not welded to each other;
In the welding step, an electrochemical cell manufacturing method in which the innermost end portion in the overlapping portion is the non-welded portion .

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