JP2018073681A - Flat sealed battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a flat sealed battery capable of reducing a resin amount and holding sealing performance by a gasket, while easily forming the gasket.SOLUTION: A flat sealed battery 1 includes: a cylindrical outer can 2 with a bottom having a side wall 21; and a flat surface part 32 that seals a cylinder part 31 of which an outer diameter is smaller than that of the side wall 21 of the outer can 2 and one opening of the cylinder part 31, and comprises: a reverse plate-like sealing plate 3 arranged in the outer can 2 in which the opening part of the cylinder part 31 is opposite to a bottom surface part 22 of the outer can 2; and a gasket 4 arranged between the side wall 21 of the outer can 2 and the cylinder part 31 of the sealing plate 3 air-tightly. The flat sealed battery is formed by sealing a power generation element 5 by the outer can 2, the sealing plate 3, and the gasket 4. The gasket 4 is integrally formed with the outer can 2 by an insert formation across an end part of an upper surface of the bottom surface part 22 from an opening end of an inner side of the side wall 21 of the outer can 2.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a flat sealed battery such as a coin-type lithium battery.

  Conventionally, it has a bottomed cylindrical outer can having a side wall, a cylindrical portion having an outer diameter smaller than that of the side wall of the outer can, and a flat portion that closes one opening of the cylindrical portion. 2. Description of the Related Art A flat sealed battery is known that includes an inverted dish-shaped sealing plate that is disposed inward of an outer can so that the portion faces the bottom surface of the outer can. In such a flat sealed battery, for example, as disclosed in Patent Document 1, in order to maintain the airtightness inside the battery and to ensure electrical insulation between the outer can and the sealing plate, A gasket is arranged at the mating part with the plate. Furthermore, in the sealed battery disclosed in Patent Document 1, a gasket is insert-molded on the sealing plate.

JP 2012-190758 A

By the way, in the structure currently disclosed by the said patent document 1, in consideration of sealing performance, the gasket is shape | molded so that the outer surface and inner surface of the cylinder part of a sealing board may be covered. Therefore, when the gasket is integrally formed on the sealing plate by injection molding, it is necessary to provide a space (cavity) for molding the gasket between the outside and inside of the cylindrical portion of the sealing plate and the molding die.
However, when the gasket is molded in this way, it is necessary to cover and flatten the resin plate to the vicinity of the flat surface inside the cylindrical portion of the sealing plate in consideration of die cutting. As a result, the cylindrical portion of the sealing plate is positioned in the middle of the cavity, and positioning of the sealing plate to the mold is very difficult.

  Therefore, as described in Patent Document 1, as a positioning of the sealing plate to the mold, a concave portion that receives the outer surface of the flat portion of the sealing plate on which the gasket is not formed is formed in the movable mold, and the sealing plate A pin having a head along the inner surface of the flat part is disposed in the circular hole of the fixed mold so as to be movable up and down, and the flat part of the sealing plate is held by the concave part of the movable mold and the pin of the fixed mold. Position.

However, in order to construct such a mold, the structure of the mold becomes complicated, and the position is shifted when the sealing plate is placed on the pin of the fixed mold and the concave portion of the movable mold is fitted to the sealing plate. As a result, the sealing plate is damaged or the shaft is displaced.
Furthermore, since the gasket must be integrally formed on the entire outside and inside of the cylindrical portion of the sealing plate, it is necessary to mold the gasket to places that are not originally required for the insulation seal, which increases the amount of wasted resin. Was. Furthermore, since resin molding is performed on the entire inside of the cylindrical portion, the internal capacity of the battery is limited.

  The present invention solves the above-described problem, and in a flat sealed battery in which a gasket is sandwiched between a sealing plate and an outer can, the gasket can be easily molded and the amount of resin can be reduced. An object of the present invention is to provide a flat sealed battery having a configuration capable of maintaining the sealing performance of the battery.

  A flat sealed battery according to the present invention includes a bottomed cylindrical outer can having a side wall, a cylindrical portion having an outer diameter smaller than that of the side wall of the outer can, and a flat portion that closes one opening of the cylindrical portion. An inverted dish-shaped sealing plate disposed inside the outer can so that the opening of the cylindrical portion faces the bottom surface of the outer can, and the side wall of the outer can and the cylinder of the sealing plate And a gasket that is sandwiched between and disposed in an airtight manner, and is a flat sealed battery in which a power generation element is sealed by the outer can, the sealing plate, and the gasket, The outer can is integrated with the outer can by insert molding from the opening end inside the side wall to the edge of the upper surface of the bottom surface.

With the above configuration, the gasket can be integrally formed inside the outer can while the outer surface of the outer can is in close contact with one mold, so that the outer can can be easily positioned during molding. The can can be reinforced to increase the strength of the gasket. Since the gasket is formed only on the inner surface of the outer can, the entire outer can can be supported by a mold, and the axis is stable. As a result, the axis of the sealing plate and the outer can can be easily aligned.
Furthermore, since the thickness of the gasket can be made uniform with respect to the wall surface of the outer can, the deformation of the sealing plate placed inside can be suppressed by the elastic deformation of the gasket due to caulking of the outer can, and the edge of the upper surface of the bottom surface of the outer can The gasket adheres well to the part.
Moreover, since it becomes unnecessary to shape | mold a gasket to the plane part vicinity inside the cylinder part of a sealing board like the past, the amount of resin can be reduced. As a result, the amount of resin can be reduced, so that the internal capacity of the battery can be increased, and the current capacity can be maintained or increased.

The gasket is integrated inside a side wall whose diameter is expanded toward the open side of the outer can, and the open end of the side wall of the outer can is caulked in a direction toward the cylindrical portion of the sealing plate, thereby the outer can It is preferable to be sandwiched between the side wall of the sealing plate and the cylindrical portion of the sealing plate in an airtight manner.
As a result, the side wall of the outer can before being combined with the sealing plate has a taper that is increased in diameter toward the open side, so that it can be easily performed when the outer can integrally molded with the gasket is removed from the mold. . Further, since the outer can in which the gasket is integrally formed has a tapered side wall whose diameter increases toward the open side, the sealing plate can be easily incorporated into the outer can.

  The gasket is formed with an annular recess that fits the tip of the cylindrical portion of the sealing plate at a portion facing the bottom edge of the outer can, and a part of the annular recess, toward the side wall opening of the outer can. It is preferable that an annular rib projecting is formed. Thus, since the annular recess and the annular rib are formed in the gasket, the sealing plate can be easily positioned with respect to the outer can, and the insulating seal effect is improved.

  In the gasket, the height of the annular rib is preferably 80% or less of the height of the entire gasket on the basis of the upper surface of the annular recess. By setting the height of the annular rib in this way, the sealing effect can be improved without wasting the amount of resin forming the gasket.

  It is preferable that an adhesion layer for improving adhesion between the outer can and the gasket is formed from the opening end inside the side wall of the outer can to the edge of the upper surface of the bottom surface. By forming the adhesion layer on the outer can in this way, the adhesion of the gasket to the outer can can be improved, and the sealing effect can be improved.

  As described above, according to the flat sealed battery of the present invention, it is possible to reduce the amount of resin and to maintain the sealing performance of the gasket while facilitating the molding of the gasket.

FIG. 1 is a cross-sectional view showing a schematic configuration of a flat sealed battery according to an embodiment of the present invention. FIG. 2 is a cross-sectional view showing a state before the outer can (positive electrode can) is fitted to the sealing plate (negative electrode can) and the side wall of the outer can is caulked. FIG. 3 is a partially enlarged cross-sectional view showing a state in which the outer can (positive electrode can) is fitted to the sealing plate (negative electrode can) and the side wall of the outer can is caulked. FIG. 4 is a cross-sectional view showing how a gasket is integrally formed on the inner surface of the side wall of an outer can (positive electrode can) with a mold. FIG. 5 is a partially enlarged cross-sectional view showing a configuration of a flat sealed battery according to another embodiment of the present invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same or equivalent parts are denoted by the same reference numerals.

A coin-type lithium battery is shown as one embodiment of the flat sealed battery of the present invention.
As shown in FIG. 1, the coin-type battery 1 is disposed inside the outer can 2 so as to cover the outer can 2 that is a bottomed cylindrical positive electrode can having a side wall 21 and the opening of the outer can 2. It is formed between the outer can 2 and the sealing plate 3, the gasket 4 disposed between the side plate 21 of the outer can 2 and the cylindrical portion 31 of the sealing plate 3. And a power generation element 5 housed in the space. The coin-type battery 1 is formed into a flat coin shape by fitting the outer can 2 and the sealing plate 3 together. In addition to the power generation element 5, a non-aqueous electrolyte (not shown) is also enclosed in the space formed between the outer can 2 and the sealing plate 3 of the coin-type battery 1.

  The outer can 2 is made of a metal material such as stainless steel and is formed in a bottomed cylindrical shape by press molding. The outer can 2 is provided with a circular bottom surface portion 22 and a cylindrical side wall 21 formed continuously with the bottom surface portion 22 on the outer periphery thereof. As shown in FIG. 2, the side wall 21 is formed in a tapered shape that spreads outward with respect to the bottom surface portion 22 in a longitudinal sectional view before being crimped toward the sealing plate 3. The outer can 2 is bent inward on the opening end side of the side wall 21 with the gasket 4 sandwiched between it and the sealing plate 3, and is caulked against the outer peripheral portion of the sealing plate 3. The root part is almost vertical.

  The sealing plate 3 is also made of a metal material such as stainless steel like the outer can 2 and is formed into a bottomed cylindrical shape by press molding. The sealing plate 3 includes a circular flat portion 32 and a cylindrical tube portion 31 formed continuously with the flat portion 32 on the outer periphery thereof. The cylindrical portion 31 includes a base end portion 31a that expands from the edge of the flat portion 32, a step portion 31b that further expands from the base end portion 31a, and an open portion that extends substantially vertically downward from the step portion 31b. 31c. As shown in FIG. 1, the open end of the side wall 21 of the outer can 2 is bent and caulked against the step 31b.

  The gasket 4 is made of a thermoplastic resin commonly used in the field of a normal lithium battery such as polypropylene (PP). The gasket 4 is injection-molded on the inner surface of the side wall 21 of the outer can 2 so as to be sandwiched between the side wall 21 of the outer can 2 and the cylindrical portion 31 of the sealing plate 3. The detailed configuration of the gasket 4 will be described later. The material of the gasket 4 is not limited to PP, but is selected from thermoplastic resins such as polyphenylene sulfide (PPS), polytetrafluoroethylene (PFA), polyetheretherketone, polyamide resin, and inorganic additives and elastomers. You may use what adjusted hardness, for example.

  The power generating element 5 includes a positive electrode material 51 (electrode material) obtained by forming a positive electrode active material or the like into a disk shape, a negative electrode material 52 formed of a metal lithium or a lithium alloy as a negative electrode active material in a disk shape, and a non-woven separator 53. It has. As shown in FIG. 1, the positive electrode material 51 is positioned inside the outer can 2, and the negative electrode material 52 is positioned inside the sealing plate 3. A separator 53 is disposed between the positive electrode material 51 and the negative electrode material 52.

  The positive electrode material 51 contains manganese dioxide as a positive electrode active material. This positive electrode material 51 is formed by forming a positive electrode mixture prepared by mixing manganese dioxide, graphite, tetrafluoroethylene-hexafluoropropylene copolymer and hydroxypropyl cellulose into a disc shape, and has a predetermined rigidity and It is held by a positive electrode ring 54 made of conductive stainless steel or the like.

  The positive electrode ring 54 includes a cylindrical portion 54 a that contacts the side surface of the positive electrode material 51, and an annular flange portion 54 b that extends from one end of the cylindrical portion 54 a toward the inside of the cylindrical portion 54 a and contacts the bottom surface of the positive electrode material 51. Are integrally formed. With the positive electrode ring 54 having such a configuration, the deformation of the positive electrode material 51 in the positive electrode ring 54 in the radial direction and one end side can be restricted. Since the other end side of the cylindrical portion 54a of the positive electrode ring 54 is in an open state, the positive electrode material 51 can freely expand. Therefore, even when the thickness of the negative electrode material 52 is reduced during discharge, the positive electrode material 51 expands toward the negative electrode material 52 along the positive electrode ring 54, thereby preventing the positive electrode material 51 and the negative electrode material 52 from separating. it can.

  The separator 53 is configured using a non-woven fabric made of fibers made of polybutylene terephthalate. The separator 53 is impregnated with a non-aqueous electrolyte in the coin-type battery 1. Note that the thickness of the separator 53 is, for example, about 0.3 to 0.4 mm.

The non-aqueous electrolyte is, for example, a solution in which LiClO ₄ is dissolved in a solution in which propylene carbonate and 1,2-dimethoxyethane are mixed.

  As shown in FIGS. 1 to 3, the gasket 4 is formed in a ring shape by insert molding from the opening end inside the side wall 21 of the outer can 2 to the edge of the upper surface of the bottom surface portion 22. Specifically, the gasket 4 is integrated with the outer seal wall 41 extending from the inner opening end of the side wall 21 to the vicinity of the bottom surface 22, and the edge of the upper surface of the bottom surface 22 of the outer can 2 continuously to the outer seal wall 41. A bottom seal portion 42 to be formed, an annular recess 43 formed in the bottom seal portion 42 and into which the tip of the cylindrical portion 31 of the sealing plate 3 is fitted, and a part of the annular recess 43 are formed. An annular rib 44 protruding toward the opening of the side wall 21 is formed.

  As shown in FIGS. 1 to 3, the outer seal wall portion 41 of the gasket 4 is formed in a substantially cylindrical shape by being in close contact with the entire inner surface of the side wall 21 of the outer can 2 and having a uniform thickness except for the root portion. Has been. Further, as shown in FIG. 2, the outer seal wall portion 41 is injection-molded along the taper of the side wall 21 of the outer can 2, so that the inner diameter becomes larger toward the opening end side as a whole. It is formed in a taper shape. Thereby, the sealing plate 3 can be easily incorporated into the outer can 2.

  The outer seal wall portion 41 covers the open portion 31c and the step portion 31b of the cylindrical portion 31 of the sealing plate 3 by caulking the side wall 21 of the outer can 2 and is pressed against the step portion 31b side of the base end portion 31a. . A portion of the outer seal wall portion 41 that faces the step portion 31b of the cylindrical portion 31 when the outer can 2 is caulked against the sealing plate 3, as shown in FIGS. 1 and 3, Compressed by the open end of the side wall 21 and the step 31 b of the cylindrical portion 31. Thereby, the space between the outer can 2 and the sealing plate 3 is sealed by the outer seal wall portion 41. Further, the side wall 21 of the outer can 2 that has been enlarged in a taper shape by caulking becomes substantially vertical, and the outer seal wall portion 41 is in close contact with the cylindrical portion 31 of the sealing plate 3 and sealed.

An annular recess 43 and an annular rib 44 are formed in the bottom seal portion 42 of the gasket 4, and the annular recess 43 is formed to have a groove width substantially the same as the thickness of the cylindrical portion 31 opening portion 31 c of the sealing plate 3. . In addition, the groove width of the annular recess 43 may be larger than the thickness of the cylindrical portion 31 opening portion 31c, or may be slightly narrower.
The height of the annular rib 44 is preferably more than 0% and not more than 80% of the total height of the gasket 4. More preferably, the height of the annular rib 44 is 10% or more and 50% or less of the total height of the gasket 4. By setting the height of the annular rib 44 in this way, it is possible to reduce the waste of the amount of resin forming the gasket 4 as much as possible and improve the sealing effect.

  By fitting the distal end portion of the cylindrical portion 31 open portion 31c of the sealing plate 3 into the annular concave portion 43 in a press-fitted state, the sealing plate 3 can be easily positioned with respect to the outer can 2, and the distal end portion of the cylindrical portion 31 is inserted into the annular concave portion 43. Since the portion is press-fitted, the space between the outer can 2 and the sealing plate 3 is reliably sealed. Further, the strength of the gasket 4 is improved by the annular rib 44.

  In the above configuration, as shown by an arrow in FIG. 3, when the opening end portion of the side wall 21 of the outer can 2 is caulked against the step portion 31 b of the sealing plate 3, the outer seal wall portion 41 of the gasket 4 is While being compressed by the open end of the side wall 21 of the can 2, it is pressed against the cylindrical portion 31. Thus, the outer seal wall portion 41 is sandwiched between the side wall 21 of the outer can 2 and the cylindrical portion 31 of the sealing plate 3 and functions as a seal. Further, the cylindrical portion 31 of the sealing plate 3 is pressed downward by caulking of the side wall 21 of the outer can 2, and the cylindrical portion 31 is pressed downward in the annular recess 43, so that the bottom seal portion 42 of the gasket 4 is pressed. Thus, the space between the bottom surface portion 22 of the outer can 2 and the cylindrical portion 31 of the sealing plate 3 is sealed. Thus, a space formed between the sealing plate 3 and the outer can 2 by the portion located on the step portion 31 b of the cylindrical portion 31 of the outer seal wall portion 41 and the bottom seal portion 42 of the gasket 4. It is sealed against the external space and maintained in isolation.

Next, a method for manufacturing the coin-type battery 1 will be described with reference to FIGS.
First, the sealing plate 3 and the outer can 2 are respectively formed by press molding. Next, as shown in FIG. 4, the gasket 4 is injection-molded on the inner surface side of the side wall 21 of the outer can 2. The state of this injection molding will be described below with reference to FIG.

  As shown in FIG. 4, a fixed mold 6 and a movable mold 7 are provided, and the fixed mold 6 is formed with a circular recess 61 in which the outer can 2 is fitted along the outer shape of the outer can 2. Further, the fixed mold 6 is provided with a movable pin 62 so as to be able to protrude at the center of the circular concave portion 61, and the movable can 62 is used to punch out the outer can 2 from the fixed mold. The movable mold 7 is formed with a circular convex portion 71 that is brought into contact with the upper surface of the bottom surface portion 22 of the outer can 2, and between the outer can 2 and the circular convex portion 71 disposed in the circular concave portion 61 of the fixed mold 6. A cavity 72 for forming the gasket 4 is formed therebetween.

  A cavity 72 for forming the gasket 4 is formed by closing the movable mold 7 in a state where the outer can 2 is disposed in the circular recess 61 of the fixed mold 6, and melting of the material of the gasket 4 is formed in the cavity 72. By injecting the resin, the gasket 4 is integrally formed on the inner surface side of the side wall 21 of the outer can 2. In addition, it is preferable to form the contact | adherence layer which raises the adhesiveness of the exterior can 2 and the gasket 4 from the opening edge inside the side wall 21 of the exterior can 2 to the edge part of the bottom face part 22 upper surface. An adhesion layer may be formed on the entire inner surface of the side wall 21 of the outer can 2. This adhesion layer is appropriately selected from materials having adhesion to both the gasket material and the metal, such as maleic acid-modified polypropylene and chlorosulfonated polyethylene. Thus, by forming the adhesion layer on the outer can 2, the adhesion of the gasket 4 to the outer can 2 can be improved.

  When the injection molding of the gasket 4 is completed, the movable mold 7 is removed, and the movable pin 62 of the fixed mold 6 is moved in the axial direction (the direction of the white arrow in FIG. 4), whereby the gasket 4 is injected. The molded outer can 2 is detached from the fixed mold 6. In this manner, a part in which the gasket 4 is injection molded on the side wall 21 of the outer can 2 is obtained.

Here, the fixed mold 6 is formed in a taper shape in which the portion forming the outer peripheral surface of the outer seal wall portion 41 and the side wall 21 of the outer can 2 gradually increase in inner diameter toward the open portion. Therefore, the outer can 2 can be easily detached from the fixed mold 6 when the outer can 2 is pushed by the movable pin 62.
Further, since the circular convex portion 71 of the movable mold 7 is also tapered so that the diameter of the tip portion gradually decreases, the movable mold 7 can be easily detached.

  Next, as shown in FIG. 2, the sealing plate 3 is disposed so that the flat portion 32 is on the lower side. And after fixing the negative electrode material 52 to the inner surface of the sealing board 3 with a conductive adhesive etc., the separator 53 and the positive electrode material 51 are piled up on this negative electrode material 52, and are arrange | positioned.

  Next, a non-aqueous electrolyte is injected into the sealing plate 3, and the outer can 2 on which the gasket 4 is injection-molded is placed on the sealing plate 3. At this time, the gasket 4 is sandwiched between the cylindrical portion 31 of the sealing plate 3 and the side wall 21 of the outer can 2 by inserting the tip of the cylindrical portion 31 of the sealing plate 3 into the annular recess 43 of the gasket 4. It becomes a state. And the opening edge part of the side wall 21 of the armored can 2 is bent and crimped inside the armored can 2 so that the step part 31b of the sealing board 3 may be covered.

  Thereby, the gasket 4 will be in the state pinched | interposed between the side wall 21 of the armored can 2, and the cylinder part 31 of the sealing board 3, as shown in FIG. That is, the outer sealing wall portion 41 of the gasket 4 is sandwiched between the step portion 31 b of the sealing plate 3 and the opening end portion of the side wall 21 of the outer can 2 by the manufacturing method as described above. Further, the end portion of the cylindrical portion 31 of the sealing plate 3 is fitted into the annular recess 43 of the gasket 4, so that the bottom seal portion 42 of the gasket 4 is located between the cylindrical portion 31 of the sealing plate 3 and the bottom surface portion 22 of the outer can 2. Sandwiched between. In this way, a coin-type battery 1 having a configuration as shown in FIG. 1 is obtained.

  With the above configuration, since the gasket 4 is integrally molded inside the outer can 2 with the entire outer surface of the outer can 2 being in close contact with one fixed mold 6, the positioning of the outer can 2 at the time of molding the gasket 4. The outer can 2 is reinforced and the strength of the gasket 4 is increased. Further, since the gasket 4 is formed only on the inner surface of the outer can 2, the entire outer surface of the outer can 2 can be supported by the fixed mold 6, and the axis is stable. As a result, the sealing plate 3 and the outer can 2 can be easily aligned with each other.

  Furthermore, since the thickness of the gasket 4 can be made uniform with a small thickness with respect to the side wall 21 of the outer can 2, it is possible to suppress deformation of the sealing plate 3 disposed on the inside by elastic deformation of the gasket 4 due to caulking of the outer can 2. In addition, the adhesion of the gasket 4 to the inner corner of the outer can 2 (periphery of the upper surface of the bottom portion 22) is improved. Further, since the side wall 21 of the outer can 2 has a taper that is expanded toward the open side, the outer can 2 can be easily removed from the mold. Incorporation into the sealing plate 3 can be easily performed.

Moreover, since it becomes unnecessary to shape | mold a gasket until it goes deep inside the cylinder part 31 of the sealing board 3 like the past, the amount of resin can be reduced. As a result, the amount of resin can be reduced, so that the internal capacity of the battery can be increased, and the current capacity can be maintained or increased.
Furthermore, since the annular recess 43 and the annular rib 44 are formed in the gasket 4, the sealing plate 3 can be easily positioned and the insulating sealing effect is improved.

  Although one embodiment of the present invention has been described above, the above-described embodiment is merely an example for carrying out the present invention. Therefore, the present invention is not limited to the above-described embodiment, and can be implemented by appropriately modifying the above-described embodiment without departing from the spirit thereof.

  For example, as shown in FIG. 5, the gasket 4 is provided with the outer seal wall portion 41 and the bottom seal portion 42 as in the above-described embodiment, but the annular recess 43 and the annular rib 44 can be prevented from being formed. . In this case, caulking is performed by pressurizing the outer can opening to the inner diameter side and downward. The front end portion of the cylindrical plate 31 of the sealing plate 3 is pressed against the bottom seal portion 42 so that the front end portion of the sealing plate bites into the bottom portion of the gasket. Also with this configuration, the sealing plate 3 and the outer can 2 can be sealed at two locations by the outer seal wall portion 41 and the bottom seal portion 42 of the gasket 4.

  In the embodiment, a material containing manganese dioxide is used as the positive electrode active material of the positive electrode material 51, and metallic lithium or a lithium alloy is used as the negative electrode active material of the negative electrode material 52. However, any other material that functions as a positive electrode active material or a negative electrode active material may be used as the positive electrode material 51 and the negative electrode material 52.

In the embodiment, whether the outer can 2 is a positive electrode can and the sealing plate 3 is a negative electrode can, conversely, the positive electrode can may be a sealing plate and the negative electrode can may be an outer can.
In the above embodiment, the sealing plate 3 and the outer can 2 are each formed in a bottomed cylindrical shape, and the coin-type battery 1 is formed in a coin shape. You may form in shapes other than column shape.

  The flat sealed battery of the present invention can be suitably applied to any flat sealed battery using a gasket.

DESCRIPTION OF SYMBOLS 1 Coin type battery 2 Exterior can 3 Sealing plate 4 Gasket 5 Power generation element 6 Fixed mold 7 Movable mold 21 Side wall 22 Bottom face part 31 Tube part 31a Base end part 31b Step part 31c Open part 32 Plane part 41 Outer seal wall part 42 Bottom seal portion 43 Annular recess 44 Annular rib 51 Positive electrode material 52 Negative electrode material 53 Separator 54 Positive electrode ring 54a Cylindrical portion 54b Flange portion 61 Circular recess 62 Movable pin 71 Circular protrusion 72 Cavity

Claims (5)

A bottomed cylindrical outer can having a side wall;
The outer casing has a cylindrical portion having an outer diameter smaller than that of the side wall of the outer can and a flat portion that blocks one opening of the cylindrical portion, and the outer opening of the outer casing can face the bottom surface of the outer can. An inverted dish-shaped sealing plate placed inside the can;
A gasket that is arranged in an airtight manner between the side wall of the outer can and the cylindrical portion of the sealing plate,
A flat sealed battery in which a power generation element is sealed by the outer can, the sealing plate and the gasket,
The flat sealed battery according to claim 1, wherein the gasket is integrated with the outer can by insert molding from an opening end inside the side wall of the outer can to an edge of the upper surface of the bottom surface.   The gasket is integrated inside a side wall whose diameter is expanded toward the open side of the outer can, and the open end of the side wall of the outer can is caulked in a direction toward the cylindrical portion of the sealing plate, thereby the outer can The flat sealed battery according to claim 1, which is sandwiched between the side wall of the sealing plate and the cylindrical portion of the sealing plate in an airtight manner.   The gasket forms an annular recess that fits the tip of the cylindrical portion of the sealing plate at a portion facing the edge of the upper surface of the bottom surface of the outer can, and a part of the annular recess, and the side wall of the outer can The flat sealed battery according to claim 1, wherein an annular rib protruding toward the opening is formed.   4. The flat sealed battery according to claim 3, wherein the gasket has a height of the annular rib that is 80% or less of a height of the entire gasket with respect to the top surface of the annular recess.   The flatness of any one of Claims 1-4 in which the adhesion layer which raises the adhesiveness of an exterior can and a gasket is formed from the opening edge inside the side wall of the said exterior can to the edge of the upper surface of a bottom face part. Sealed battery.

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