JP6892495B2 - Secondary battery - Google Patents

Description

In the present invention, the pressing force generated by the compression of the gasket formed by the protrusion of the battery lid and the insulating plate is stably applied in the axial direction of the connection terminal by the tapered portion of the battery lid to form a shaft seal. Regarding a square secondary battery that obtains a function.

As a conventional example, there is a patent that expands the diameter of the shaft by crimping the shaft of the connection terminal in the vertical direction and presses the gasket between the shaft through hole of another member to realize the seal in the axial direction. It is disclosed in Patent Document 1.

JP-A-2009-76394

In the prior art, since there is no structure (part) for blocking the flow (meat escape) of the gasket pressed (compressed) by the diameter expansion of the shaft portion, the meat escape of the gasket occurs, and the time passes due to vibration or creep. There is a concern that the sealing performance will be reduced. Further, especially when the current collector plate, the external terminal, and the connection terminal are made of three parts, the electrolytic solution may seep out through the connection terminal.

The present invention has been made in view of the above points, and an object of the present invention is in addition to the conventional sealing technique of pressing the gasket in the caulking direction by the unevenness provided on the lid or the flange portion, the present application applies. Further, it is possible to obtain the function of the shaft seal by applying a pressing force due to the buildup of the gasket to the shaft portion of the connection terminal. This is to provide a square secondary battery capable of ensuring a longer-term sealing property than before.

In order to solve the above problems, the square secondary battery according to one aspect of the present invention houses the power storage element, the current collector plate connected to the power storage element, the power storage element and the current collector plate, and is provided with an opening. A battery container, a lid that closes the opening of the battery container and has an external terminal arranged therein, a connection terminal that connects the external terminal and the current collector plate, and an insulating plate that insulates the external terminal and the lid are provided and connected. A gasket is provided around the shaft of the terminal to form a lump portion, the gasket is provided with a pair of narrow portions, and the lid is arranged between the pair of narrow portions, and the shaft of the connection terminal is provided. A tapered portion having a taper angle for generating a compressive load is provided in the direction of the above, and a protrusion protruding from the lid or a current collector is provided at a position corresponding to the narrow portion on one side of the pair of narrow portions. A protrusion protruding from the plate is formed, and an insulating plate protrusion protruding from the insulating plate is formed at a position corresponding to the narrow portion on the other side of the pair of narrow portions, and the protrusion protruding from the lid. Is provided apart from the tapered portion.

According to the present invention, in addition to the conventional sealing technique of pressing the gasket in the caulking direction by the unevenness provided on the lid or the flange portion, the present application further applies a pressing force due to the wall lump of the gasket to the shaft portion of the connection terminal. This makes it possible to obtain the function of a shaft seal. As a result, it is possible to guarantee the sealing property for a longer period of time than before. Issues, configurations, and effects other than those described above will be clarified by the following description of the embodiments.

An exploded perspective view of a square secondary battery An exploded perspective view of the wound electrode group Schematic cross-sectional view of Example 1 before pressing Schematic cross-sectional view of Example 1 during pressing Schematic cross-sectional view during caulking of Example 1 Schematic cross-sectional view of Example 1 after caulking Schematic cross-sectional view of Example 2 Schematic cross-sectional view of Example 3 Schematic cross-sectional view of a modified example of Example 1 Schematic cross-sectional view of Example 4 Schematic cross-sectional view of Example 5 Schematic cross-sectional view of Example 6

Hereinafter, examples of the present invention will be described with reference to the drawings.

<< Example 1 >>
FIG. 1 is an exploded perspective view of a square secondary battery.
The square secondary battery 100 includes a battery can 1 and a lid 6. The battery can 1 and the lid 6 are made of a metal material such as an aluminum alloy, and are formed by deep drawing and pressing.

A winding electrode group 3 (see FIG. 2) is built in the battery can 1, and the opening 1a of the battery can 1 is sealed by a lid 6. The lid 6 has a substantially rectangular flat plate shape, and is welded so as to close the opening 1a of the battery can 1 to seal the battery can 1. The lid 6 is provided with a positive electrode output unit 14 and a negative electrode output unit 12 fixed to the lid 6 by an insulating member 5 by insert molding. The wound electrode group 3 is charged via the positive electrode output unit 14 and the negative electrode output unit 12, and electric power is supplied to the external load. A gas discharge valve 10 is integrally provided on the lid 6, and when the pressure inside the battery container rises, the gas discharge valve 10 opens to discharge gas from the inside, and the pressure inside the battery container is reduced. As a result, the safety of the square secondary battery 100 is ensured.

The battery can 1 of the square secondary battery 100 has a rectangular bottom surface 1d, a wide surface 1b rising from a pair of long sides of the bottom surface 1d, a narrow surface 1c rising from a pair of short sides of the bottom surface 1d, and these wide surfaces 1b. It also has an opening 1a that is open upward at the upper end of the narrow surface 1c. The wound electrode group 3 is housed in the battery can 1 via the insulating protective film 2.

The wound electrode group 3 is formed by winding a strip-shaped electrode into a flat shape, and is formed continuously between a pair of curved portions facing each other having a semicircular cross section and the pair of curved portions. It has a flat surface portion. The winding electrode group 3 is inserted into the battery can 1 from one curved portion side so as to have the winding axis direction along the lateral width direction of the battery can 1 and faces the bottom surface 1d, and the other curved portion side is an opening. It is arranged on the 1a side.

The positive electrode foil exposed portion 34c of the wound electrode group 3 is electrically connected to the positive electrode output portion 14 provided on the lid 6 via the positive electrode current collector plate 44. Further, the negative electrode foil exposed portion 32c of the wound electrode group 3 is electrically connected to the negative electrode output portion 12 provided on the lid 6 via the negative electrode current collector plate 24. As a result, electric power is supplied from the wound electrode group 3 to the external load via the positive electrode current collecting plate 44 and the negative electrode current collecting plate 24, and the wound electrode group 3 is supplied via the positive electrode current collecting plate 44 and the negative electrode current collecting plate 24. Externally generated power is supplied to and charged.

A gasket 5 and an insulating plate 7 are provided on the battery lid 6 in order to electrically insulate the positive electrode current collecting plate 44 and the negative electrode current collecting plate 24, and the positive electrode external terminal 14 and the negative electrode external terminal 12 from the battery lid 6, respectively. Has been done. Further, after injecting the electrolytic solution into the battery can 1 from the liquid injection port 9, the liquid injection plug 11 is joined to the battery lid 6 by laser welding to seal the liquid injection port 9, and the flat winding type secondary battery is used. Seal 100.

Here, examples of the material for forming the positive electrode current collector plate 44 include an aluminum alloy, and examples of the material for forming the negative electrode current collector plate 24 include a copper alloy. Examples of the material for forming the insulating member 5 include a resin material having an insulating property such as polybutylene terephthalate, polyphenylene sulfide, and perfluoroalkoxy alkane resin.

Further, the battery lid 6 is provided with a liquid injection hole 9 for injecting the electrolytic solution into the battery container, and the liquid injection hole 9 is a liquid injection plug after the electrolytic solution is injected into the battery container. Sealed by 11. Here, as the electrolytic solution to be injected into the battery container, for example, a non-aqueous electrolytic solution in which a lithium salt such as lithium _{hexafluorophosphate (LiPF 6) is dissolved in a carbonic acid ester-based organic solvent such as ethylene carbonate is used.} Can be applied.

The positive electrode external terminal 14 and the negative electrode external terminal 12 have a welded joint portion to be welded to a bus bar or the like. The welded joint has a flat surface that is arranged above the gasket 5 and parallel to the outer surface of the battery lid 6, and a bus bar or the like is brought into contact with the flat surface to be welded. ..

The positive electrode current collector plate 44 and the negative electrode current collector plate 24 extend toward the bottom surface along the wide surface of the battery can 1 and face the positive electrode foil exposed portion 34c and the negative electrode foil exposed portion 32c of the wound electrode group 3. It has a positive electrode side connection end 42 and a negative electrode side connection end 22 which are connected in a superposed state.
An insulating protective film 2 is wound around the wound electrode group 3 with the direction along the flat surface of the wound electrode group 3 and orthogonal to the winding axis direction of the wound electrode group 3 as the central axis direction. .. The insulating protective film 2 is made of a single sheet or a plurality of film members made of synthetic resin such as PP (polypropylene), and is parallel to the flat surface of the winding electrode group 3 and orthogonal to the winding axis direction. It has a length that allows it to be wound around the direction as the winding center.

FIG. 2 is an exploded perspective view showing a state in which a part of the wound electrode group is unfolded.
The winding electrode group 3 is configured by winding the negative electrode 32 and the positive electrode 34 in a flat shape with the separators 33 and 35 in between. In the wound electrode group 3, the outermost electrode is the negative electrode 32, and the separators 33 and 35 are wound on the outer side thereof. The separators 33 and 35 have a role of insulating between the positive electrode 34 and the negative electrode 32.

The portion of the negative electrode 32 to which the negative electrode mixture layer 32b is applied is larger in the width direction than the portion of the positive electrode 34 to which the positive electrode mixture layer 34b is applied. The negative electrode mixture layer 32b is always sandwiched between the coated portions. The positive electrode foil exposed portion 34c and the negative electrode foil exposed portion 32c are bundled at a flat surface portion and connected by welding or the like. The separators 33 and 35 are wider in the width direction than the portion coated with the negative electrode mixture layer 32b, but are wound at positions where the metal foil surface at the end is exposed at the positive electrode foil exposed portion 34c and the negative electrode foil exposed portion 32c. Therefore, it does not hinder the case of bundling and welding.

The positive electrode electrode 34 has a positive electrode active material mixture on both sides of the positive electrode foil which is a positive electrode current collector, and the positive electrode foil exposed portion where the positive electrode active material mixture is not applied to one end in the width direction of the positive electrode foil. 34c is provided. The negative electrode electrode 32 has a negative electrode active material mixture on both sides of the negative electrode foil which is a negative electrode current collector, and the negative electrode foil exposed portion where the negative electrode active material mixture is not applied to the other end in the width direction of the negative electrode foil. 32c is provided. The positive electrode foil exposed portion 34c and the negative electrode foil exposed portion 32c are regions where the metal surface of the electrode foil is exposed, and are wound so as to be arranged at positions on one side and the other side in the winding axis direction.

Regarding the negative electrode 32, 10 parts by weight of polyvinylidene fluoride (hereinafter referred to as PVDF) was added as a binder to 100 parts by weight of the amorphous carbon powder as the negative electrode active material, and N was added as a dispersion solvent. -Methylpyrrolidone (hereinafter referred to as NMP) was added and kneaded to prepare a negative electrode mixture. This negative electrode mixture was applied to both sides of a copper foil (negative electrode foil) having a thickness of 10 μm, leaving welded portions (negative electrode uncoated portions). Then, through the drying, pressing, and cutting steps, a negative electrode 32 having a thickness of 70 μm in the negative electrode active material coating portion containing no copper foil was obtained.

In this embodiment, the case where amorphous carbon is used as the negative electrode active material has been illustrated, but the present invention is not limited to this, and natural graphite capable of inserting and removing lithium ions and various artificial graphite materials are used. , A carbonaceous material such as coke, a compound such as Si or Sn (for example, SiO, TiSi _2, etc.), or a composite material thereof, and the particle shape thereof is also scaly, spherical, fibrous, lumpy, etc., in particular. There are no restrictions.

Regarding the positive electrode electrode 34, 10 parts by weight of scaly graphite as a conductive material and 10 parts by weight of PVDF as a binder were added to 100 parts by weight of _{lithium manganate (chemical formula LiMn 2} O _{4) as a positive electrode active material.} , NMP was added as a dispersion solvent to this, and a positive electrode mixture was kneaded to prepare a positive electrode mixture. This positive electrode mixture was applied to both sides of an aluminum foil (positive electrode foil) having a thickness of 20 μm, leaving welded portions (positive electrode uncoated portions). Then, through a drying, pressing, and cutting steps, a positive electrode 31 having a thickness of 90 μm in the positive electrode active material coating portion containing no aluminum foil was obtained.

Further, in the present embodiment, the case where lithium manganate is used as the positive electrode active material has been illustrated, but other lithium manganate having a spinel crystal structure, a lithium manganese composite oxide obtained by partially substituting or doping with a metal element, or a layered layer. Lithium cobalt oxide or lithium titanate having a crystal structure or a lithium-metal composite oxide obtained by substituting or doping a part of these with a metal element may be used.

Further, in the present embodiment, the case where PVDF is used as a binder for the coated portion in the positive electrode and the negative electrode is illustrated, but polytetrafluoroethylene (PTFE), polyethylene, polystyrene, polybutadiene, butyl rubber, nitrile rubber, and styrene Use polymers such as butadiene rubber, polysulfide rubber, nitrocellulose, cyanoethyl cellulose, various latexes, acrylonitrile, vinyl fluoride, vinylidene fluoride, propylene fluoride, chloroprene fluoride, acrylic resins, and mixtures thereof. Can be done.

Further, as the shaft core, for example, a resin sheet having a higher bending rigidity than any of the positive electrode foil, the negative electrode foil, and the separators 33 and 35 can be used.

FIG. 3 shows a schematic cross-sectional view at the time of caulking in the first embodiment. In this embodiment, the negative electrode side will be described as a representative, but of course, the present embodiment can be applied even if it is the positive electrode side.

In the schematic cross-sectional view shown in FIG. 3, the state in which the parts before caulking are overlapped is shown in FIG. 3 (a), the state in which the gasket 5 is pressed by the compressive load 110 in the overlapped state is shown in FIG. In FIG. 3 (c) in which the end portion of the connection terminal 12a is expanded in a tapered shape while being pressed with, the negative electrode connection portion temporary caulking 12aa that is expanded in a tapered shape is used as the negative electrode connecting portion caulking 12aa a. FIG. 3 (d) shows a crimped state. With such a structure, the gasket 5 is provided with a narrow portion 55a formed by the battery lid protrusion 6a, a narrow portion 55b formed by the insulating plate protrusion 7aa, the connection terminal 12a, and the battery lid 6. Be done.

The battery lid protrusion 6a and the insulating plate protrusion 7aa shown in FIG. 3 (a) are in the state shown in FIG. 3 (b), and the battery lid protrusion compression load 110b and the insulating plate are located at opposite positions of the gasket 5, respectively. A protrusion compression load 110a is generated.

With the compressive load 110 shown in FIG. 3 (b) applied, as shown in FIG. 3 (c), the end of the connection terminal 12a is pushed in a tapered shape by, for example, a punch having a taper shape of 90 ° (not shown). By expanding, a negative electrode connection portion temporary caulking 12aa is formed at the end of the connection terminal 12a, and the gasket 5a is held in a compressed state.

As shown in FIG. 3D, the negative electrode connection terminal temporary caulking 12aa shown in FIG. 3C is caulked into the negative electrode connecting portion 12aaa having a target shape, for example, by a dome-shaped punch (not shown). The gasket padding a portion 5a generates surface pressure on the contact surface with the connection terminal 12a and the contact surface with the battery lid protrusion 6a in a compressed state, but the battery lid taper portion 6b is the shaft of the negative electrode connection portion 12a. The battery lid taper portion is molded at a taper angle that enables a compressive load of 110d to be generated in the direction. The battery lid tapered portion 6b can ensure long-term sealing performance by stably generating the compressive load 110d for a long period of time.
As shown in FIG. 6, the protrusion 6a may be arranged at a position separated from the taper portion 6b.
The above is a brief summary of this embodiment. In this embodiment, the power storage element (3), the power collection plate (24, 44) connected to the power storage element (3), the power storage element (3), and the power collection plate (24, 44) are housed. A battery container (1) provided with an opening (1a), a lid that closes the opening (1a) of the battery container (1) and has an external terminal (12, 14) arranged, and an external terminal (12, 14). A connection terminal (12a, 14a) for connecting to a current collector plate (24, 44) is provided, and a gasket (5) is provided around the axis of the connection terminal (12a, 14a), and the gasket (5) has a gasket (5). Is provided with a pair of narrow portions (55a, 55b), and the lid (6) is provided with a tapered portion (6b) arranged between the pair of narrow portions. With such a structure, the meat of the gasket can be collected in a pair of narrow portions, and the meat can be pressed against the connection terminals (12a, 14a), so that the sealing at the shaft portion can be realized for a long period of time. be able to. Therefore, leakage from the connection terminals 12a and 14a due to the deterioration of the sealing property can be eliminated.
Further, in this embodiment, the tapered portion (6b) is provided on the lid (6) side, and is located at a position corresponding to the narrow portion (55a) on one side of the pair of narrow portions (55a, 55b). , A protrusion (6a) protruding from the lid (6) is formed.
Further, in this embodiment, the protruding portion (6a) is provided apart from the tapered portion (6b).

<< Example 2 >>
Next, Example 2 will be described. The difference between the second embodiment and the first embodiment is that the end of the tapered portion 6b of the battery lid 6 on the external terminal side forms the end of the opening through which the connection terminal 12a of the battery lid 6 is inserted (). In the first embodiment, there was a flat portion connected from the tapered portion 6b).
FIG. 4 shows a schematic cross-sectional view after caulking in Example 2. In the same manner as in the first embodiment, the negative electrode connection portion temporary caulking 12aa is formed while the gasket 5 is pressed by the compressive load 110 from the state where the parts are overlapped, and finally the negative electrode connection portion caulking 12aa is formed.

The gasket meat pool a portion 5a generates surface pressure on the contact surface with the connection terminal 12a and the contact surface with the battery lid protrusion 6a in the compressed state, but the battery lid taper portion 6b is similar to the first embodiment. The battery lid taper portion is molded at a taper angle that enables a compression load 110d to be generated in the direction of the axis of the negative electrode connection portion 12a. The battery lid tapered portion 6b can ensure long-term sealing performance by stably generating the compressive load 110d for a long period of time.
The above is a summary of this embodiment. The present embodiment is characterized in that the end portion of the tapered portion (6b) is formed at a position corresponding to the narrow portion (55b) on the other side of the pair of narrow portions (55a, 55b). To do. With such a configuration, the gasket meat pool a portion 5a can be pushed in a wider area, so that the reliability becomes higher.

<< Example 3 >>
Subsequently, Example 3 will be described. The difference between the third embodiment and the first embodiment is that the tapered portion 6b of the battery lid 6 and the protruding portion 6a of the battery lid 6 are continuously provided.
FIG. 5 shows a schematic cross-sectional view after caulking in Example 3. Similar to Examples 1 and 2, a caulking step of forming the negative electrode connecting portion temporary caulking 12aa in a state where the gasket 5 is pressed by the compressive load 110 from the state where the parts are overlapped, and finally forming the negative electrode connecting portion caulking 12aa is performed. Do.

In this embodiment, by providing the protrusion 6a continuously from the tapered portion provided on the lid, the gasket 5 due to the pressing of the gasket 5 by caulking can easily flow to the gasket padding a portion 5a facing the tapered portion, and the gasket. It is possible to prevent the meat of the gasket 5 from escaping to the meat pool b portion 5b. Similar to Examples 1 and 2, the battery lid taper portion 6b is formed at a taper angle that enables the battery lid taper portion compression load 110d to be generated in the direction of the axis of the negative electrode connecting portion 12a. The battery lid tapered portion 6b can ensure long-term sealing performance by stably generating the compressive load 110d for a long period of time.
The above is a summary of this embodiment. In this embodiment, the protrusion (6a) is provided continuously from the taper portion (6b). With such a configuration, the gasket 5 can easily flow to the gasket meat pool a portion 5a facing the tapered portion, and it is possible to prevent the meat escape of the gasket 5 to the gasket meat pool b portion 5b. Become.

<< Example 4 >>
Subsequently, Example 4 will be described. The difference between the fourth embodiment and the first embodiment is that the protrusion 24a is provided on the current collector plate 24 side.
FIG. 7 shows a schematic cross-sectional view after caulking in Example 4. Similar to Examples 1 and 2, a caulking step of forming the negative electrode connecting portion temporary caulking 12aa in a state where the gasket 5 is pressed by the compressive load 110 from the state where the parts are overlapped, and finally forming the negative electrode connecting portion caulking 12aa is performed. Do.

By providing the protrusion 24a on the current collector plate 24, it is possible to prevent the gasket 5 from flowing in the axial direction by pressing the gasket 5 by caulking, and to prevent the gasket 5 from escaping to the gasket meat pool b portion 5b. .. Further, the effect can be obtained in the same manner as the structure having the separating portion 6c shown in FIG. 6 on the lid. Similar to Examples 1 and 2, the battery lid taper portion 6b is formed at a taper angle that enables the battery lid taper portion compression load 110d to be generated in the direction of the axis of the negative electrode connecting portion 12a. The battery lid tapered portion 6b can ensure long-term sealing performance by stably generating the compressive load 110d for a long period of time.
The above is a brief summary of this embodiment. In this embodiment, of the pair of narrow portions (55a, 55b), a protrusion protruding from the current collector plate (24, 44) is provided at a position corresponding to the narrow portion (55a, 55b) on one side. It is characterized by being formed. Even with such a configuration, the same effect as in the first embodiment can be achieved.

<< Example 5 >>
Subsequently, Example 5 will be described. The difference between the fifth embodiment and the first embodiment is that the tapered portion 6b faces the tapered portion 6b, and the protrusion 24a is provided on the current collector plate 24 side.
FIG. 8 shows a schematic cross-sectional view after caulking in Example 5. Similar to Examples 1 and 2, a caulking step of forming the negative electrode connecting portion temporary caulking 12aa in a state where the gasket 5 is pressed by the compressive load 110 from the state where the parts are overlapped, and finally forming the negative electrode connecting portion caulking 12aa is performed. Do.

The gasket padding a portion 5a has a contact surface with the connection terminal 12a and a battery lid protrusion 6a in a compressed state higher than that of Examples 1 and 2 due to an increase in the amount of compression due to the negative electrode current collector plate taper portion facing protrusion 24b. Surface pressure is generated on the contact surface with the negative electrode current collector plate and the contact surface with the tapered portion protrusion 24b of the negative electrode current collector. Similar to Examples 1 and 2, the battery lid taper portion 6b is formed at a taper angle that enables the battery lid taper portion compression load 110d to be generated in the direction of the axis of the negative electrode connecting portion 12a. The battery lid tapered portion 6b can ensure long-term sealing performance by stably generating the compressive load 110d for a long period of time.
The above is a brief summary of this embodiment. The present embodiment is characterized in that a protrusion is provided on the current collector plate portion on which the tapered portion faces. With such a structure, the contact surface of the connection terminal and the contact surface with the battery lid protrusion in a compressed state higher than those of Examples 1 and 2 due to the increase in the amount of compression due to the current collector plate taper portion facing protrusion. In addition, surface pressure can be generated at the contact surface with the protruding portion of the taper portion of the current collector plate, and further long-term sealing performance can be ensured.

<< Example 6 >>
Subsequently, Example 6 will be described. The difference between the sixth embodiment and the first embodiment is that the shaft portions of the connection terminals 12a and 14a on the current collector plate 24 side are thickened to achieve the same effect as that of the fifth embodiment.
FIG. 9 shows a schematic cross-sectional view after caulking in Example 6. Similar to Examples 1, 2 and 3, the negative electrode connection portion temporary caulking 12aa is formed while the gasket 5 is pressed by the compressive load 110 from the state where the parts are overlapped, and finally the negative electrode connection portion caulking 12aa is formed. Perform the process.

In the gasket padding a5a, the outer diameter B portion 12ac of the negative electrode connecting portion 12a is larger than the other outer diameter A portion 12ab while the battery lid tapered portion 6b faces, and the amount of compression increases due to the increase in the amount of compression. A surface pressure is generated on the contact surface with the connection terminal 12a, the contact surface with the battery lid protrusion 6a, and the contact surface with the negative electrode current collector plate protrusion 24a in a compressed state higher than 2. Similar to Examples 1 and 2, the battery lid tapered portion 6b is formed at a taper angle that enables the battery lid tapered portion compressed surface pressure 110d to be generated in the direction of the axis of the negative electrode connecting portion 12a. The battery lid tapered portion 6b can ensure long-term sealing performance by stably generating the compressed surface pressure 110d for a long period of time.
The above is a brief summary of the examples. The present embodiment is characterized in that the diameter (12ac) of the connection terminal facing the tapered portion (6b) is larger than the other diameters (12ab). By enlarging a part of the shaft portions of the connection terminals 12a and 14a, the same effect as in the fifth embodiment (improvement of long-term sealing performance by increasing the amount of compression of the gasket 5) can be obtained.

In Examples 1, 2, 3, 4, 5, and 6, only the configuration on the negative electrode side is shown, but the present embodiment is not limited to the negative electrode side, and at least one of the positive electrode side and the negative electrode side is applied. In this embodiment, the positive electrode side has the same configuration as the negative electrode side.
Further, although the taper shape has been described as an example in the embodiment, the R shape may be used, and the problem to be solved by the present application can be solved in the same manner.
Further, in any of the embodiments, the shaft portions of the connection terminals 12a and 14a with which the tapered portions 6b face each other may be provided with irregularities by rolling or cutting. With such a configuration, the long-term sealing performance can be improved.
Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above-described embodiments, and various designs are designed without departing from the spirit of the present invention described in the claims. You can make changes. For example, the above-described embodiment has been described in detail in order to explain the present invention in an easy-to-understand manner, and is not necessarily limited to the one including all the described configurations. Further, it is possible to replace a part of the configuration of one embodiment with the configuration of another embodiment, and it is also possible to add the configuration of another embodiment to the configuration of one embodiment. Further, it is possible to add / delete / replace a part of the configuration of each embodiment with another configuration.

1 Battery can 1a Opening 1b Wide side 1c Narrow side 1d Bottom 2 Insulation protective film 3 Winding group 5 Gasket 5a Gasket lump a part 5b Gasket lump b part 6 Battery lid 6a Battery lid protrusion 6b Battery lid taper part 6c Battery cover separator 7a Insulation plate a
7aa Insulation plate protrusion 7b Insulation plate b
9 Liquid injection port 10 Gas discharge valve 11 Liquid injection plug 12 Negative electrode external terminal 12a Negative electrode connection part 12aa Negative electrode connection part Temporary caulking 12aa Negative electrode connection part caulking 12ab Outer diameter A part 12ac Outer diameter B part 14 Positive electrode external terminal 14a Positive electrode connection part 21 Negative electrode current collector base 22 Negative electrode connection end 23 Negative electrode side opening hole 24 Negative electrode current collector plate 24a Negative electrode current collector plate protrusion 24b Negative electrode current collector plate Tapered part Opposing protrusion 26 Negative electrode side through hole 32 Negative electrode 32a Negative electrode foil 32b Negative electrode Mixture layer 32c Negative electrode foil exposed portion 33 Separator 34 Positive electrode electrode 34a Positive electrode foil 34b Positive electrode mixture layer 34c Positive electrode foil exposed portion 35 Separator 41 Positive electrode current collector base 42 Positive electrode connection end 44 Positive electrode current collector plate 46 Positive electrode side through hole 100 Secondary battery 110 Compressed load 110a Insulating plate protrusion Compressed load
110b Battery lid protrusion compression load 110c Insulation plate pinching part compression load 110d Battery lid taper part compression load

Claims (4)

Power storage element and
A current collector plate connected to the power storage element and
A battery container in which the power storage element and the current collector plate are housed and provided with an opening,
A lid that closes the opening of the battery container and has an external terminal arranged on it,
A connection terminal for connecting the external terminal and the current collector plate,
In a secondary battery provided with an insulating plate that insulates the external terminal and the lid.
A gasket is provided around the shaft of the connection terminal to form a meat pool.
The gasket is provided with a pair of narrow portions.
The lid is provided with a tapered portion arranged between the pair of narrow portions and having a taper angle for generating a compressive load in the direction of the axis of the connection terminal.
A protrusion protruding from the lid or a protrusion protruding from the current collector plate is formed at a position corresponding to the narrow portion on one side of the pair of narrow portions.
An insulating plate protrusion protruding from the insulating plate is formed at a position corresponding to the narrow portion on the other side of the pair of narrow portions.
A secondary battery characterized in that a protrusion protruding from the lid is provided apart from the tapered portion. In the secondary battery according to claim 1,
A secondary battery characterized in that an end portion of the tapered portion is formed at a position corresponding to the narrow portion on the other side of the pair of narrow portions. In the secondary battery according to claim 1,
A secondary battery characterized in that a protrusion is provided on the current collector plate with which the taper portion faces. In the secondary battery according to claim 1,
A secondary battery characterized in that the diameter of the connection terminal with which the tapered portion faces is larger than the other diameters.

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