JP2011054379A - Cylindrical battery - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cylindrical battery which improves the durability against external force such as vertical vibration or impact on an axis. <P>SOLUTION: The cylindrical battery 1 includes a group of electrodes 10 and a positive electrode collecting member 31 whose upper part mounts a rubber gasket 43 to cover a cleavage valve 37 and upper and lower surfaces and outer circumferential surface of a circumference 3a of a lid 3 through an insulating plate 41; the battery container 2 tightly sealed by compressing and caulking in an axial direction; and a minute projection 31d formed on the upper surface of an upper cylinder part 31c of the positive electrode collecting member 31 and the minute projection 31d, which is cutting into the insulating plate 41. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a cylindrical battery.

  A cylindrical battery represented by a lithium secondary battery or the like has a structure in which one of current collecting members connected to a positive electrode or a negative electrode wound around an axis is connected to a lid and the other is connected to a battery container. In general, the positive electrode is connected to the lid and the negative electrode is connected to the battery container, but some have a reverse connection structure.

  The lid and the battery container are insulated by a gasket made of rubber or the like. In this case, a structure is known in which insulation is achieved by a gasket and at the same time a lid is held. An example of a method for manufacturing such a cylindrical battery is as follows. First, a substantially V-shaped groove is formed by deforming a part of the battery container so as to protrude inward by pressing or the like on the upper side of the cylindrical container. Form. Next, a cylindrical gasket is disposed above the groove, and an outer peripheral edge of a disc-shaped lid slightly smaller than the gasket is placed thereon. Then, the battery container and the gasket are caulked in the axial direction by a press or the like, and the lid and the gasket are fixed between one side edge of the battery container and the groove. By fixing the lid, the current collecting member connected to the lid is fixed and the connected current collecting member is fixed, thereby fixing the power generation element including the positive electrode and the negative electrode. (For example, see Patent Document 1)

JP 2009-104979 A (FIG. 3)

  In the case of the above structure, the current collecting member is held in the axial direction of the cylindrical battery by the gasket, but is not held in the direction perpendicular to the axial direction.

  The cylindrical battery of the present invention includes an electrode group in which a positive electrode and a negative electrode are wound around an axial core via a separator, and is disposed on one end side and the other end side in the axial direction of the electrode group, respectively. A pair of current collecting members connected to one and the other of the battery, an electrode group and the pair of current collecting members, a battery container connected to one of the pair of current collecting members, and the other of the pair of current collecting members A lid connected to the other, an insulating member disposed between the other of the pair of current collecting members and the lid, and an outer peripheral edge of the lid and one side edge in the axial direction of the battery container, A rubber gasket fixed by an outer peripheral edge of the lid and a pressure contact force acting in the axial direction of the battery case, and the current collecting member is pressed against the insulating member and applied to an external force acting in a direction perpendicular to the axial direction. It is characterized by holding the electrode group against it.

  According to the cylindrical battery of the present invention, the current collecting member can be reliably held against an external force acting in the axial direction, and is resistant to external forces such as impact and vibration acting in a direction perpendicular to the axial direction. Can be improved.

Sectional drawing which shows one Embodiment of the cylindrical battery of this invention. FIG. 2 is an external perspective view in which a part of an electrode group of the cylindrical battery shown in FIG. 1 is cut. FIG. 2 is an exploded perspective view of the cylindrical battery shown in FIG. 1. Sectional drawing which shows the 1st process of the sealing method using the gasket in the cylindrical battery of this invention. Sectional drawing which shows the process of following FIG. Sectional drawing which shows the process of following FIG. The perspective view which shows the 1st modification of the positive electrode current collection member used for the cylindrical battery of this invention. FIG. 8 is a sectional view taken along line VIII-VIII in FIG. 7. The perspective view which shows the 2nd modification of the positive electrode current collection member used for the cylindrical battery of this invention. XX sectional view taken on the line of FIG. The perspective view which shows the 3rd modification of the positive electrode current collection member used for the cylindrical battery of this invention. FIG. 12 is a cross-sectional view taken along line XII-XII in FIG. 11. The perspective view which shows the 4th modification of the positive electrode current collection member used for the cylindrical battery of this invention. FIG. 14 is a cross-sectional view taken along line XIV-XIV in FIG. 13.

(Embodiment 1)
−Structure of cylindrical battery−
Hereinafter, an embodiment of a cylindrical battery of the present invention will be described with reference to the drawings by taking a lithium secondary battery as an example.
FIG. 1 is a cross-sectional view showing an embodiment of a cylindrical battery according to the present invention, and FIG. 2 is an external perspective view of a part of an electrode group of the cylindrical battery shown in FIG. 3 is an exploded perspective view of the cylindrical battery shown in FIG. However, in FIG. 3, the negative electrode current collector plate and the battery container are not shown.
The cylindrical battery 1 has dimensions of, for example, an outer diameter of 40 mmφ and a height of 100 mm.
This cylindrical battery 1 accommodates each component for power generation described below in a cylindrical battery container 2 with a bottom and a hat-shaped lid 3. The battery container 2 is deformed so that the open side portion protrudes inward, and a groove 2a is formed.

  Reference numeral 10 denotes an electrode group. As illustrated in FIG. 2, the electrode group 10 includes a shaft core 15, a positive electrode sheet (positive electrode) 11 wound around the shaft core 15, a negative electrode sheet (negative electrode) 12, and a positive electrode sheet 11 and a negative electrode sheet. 12 and a separator 13 disposed between the two.

  The positive electrode sheet 11 is formed of an aluminum foil, and a positive electrode processing portion 11a that has been subjected to a positive electrode treatment for applying a positive electrode active material or the like on both sides; Have A large number of positive electrode leads 11b1 are integrally formed at equal intervals in the positive electrode untreated portion 11b.

To describe an example of a method of forming a positive electrode sheet 11, the positive electrode sheet 11 is used as the positive electrode active material a typical lithium manganese oxide (LiMn ₂ O ₄₎ as a lithium manganese complex oxide is produced as follows. To 90 parts by weight of the positive electrode active material, 10 parts by weight of flake graphite as a conductive agent and 5 parts by weight of polybilinyl difluoride (PVDF) as a binder are added, and N-methyl-2 is used as a dispersion solvent. -The slurry in which pyrrolidone is added and kneaded is uniformly applied to both sides of an aluminum foil having a thickness of 20 µm, dried, then pressed and cut.

  The negative electrode sheet 12 is formed of a copper foil, and a negative electrode treatment portion 12a that has been subjected to a negative electrode treatment for applying a negative electrode active material or the like on both sides; Have A large number of negative electrode leads 12b1 are integrally formed at equal intervals in the negative electrode untreated portion 12b.

  If an example of the formation method of the negative electrode sheet 12 is demonstrated, the negative electrode sheet 12 will be produced as follows using an amorphous carbon powder as a carbon material of a negative electrode active material. A slurry obtained by adding 10 parts by weight of polyvinylidene fluoride (PVDF) as a binder to 90 parts by weight of amorphous carbon powder, and adding and kneading N-methyl-2-pyrrolidone as a dispersion solvent to this is 10 μm thick. After uniformly applying to both sides of the rolled copper foil and drying, it is pressed and cut.

The separator 13 is, for example, a polyethylene porous film having a thickness of 40 μm.
The shaft core 15 has a hollow thin cylindrical shape extending in the axial direction (vertical direction in the drawing), and a positive electrode current collecting member 31 is press-fitted into the upper portion thereof. The positive electrode current collecting member 31 is formed of, for example, aluminum, and has a lower cylindrical portion 31b that is formed on the shaft core side of the disc-shaped base portion 31a so as to protrude from the lower surface side and press-fitted into the inner surface of the shaft core 15. It has an upper cylinder part (side part) 31c protruding to the upper surface side on the outer peripheral edge.

  FIG. 7 is an enlarged perspective view of the positive electrode current collecting member, and FIG. 8 is a cross-sectional view taken along line VIII-VIII in FIG. The upper cylindrical portion 31c of the positive electrode current collecting member 31 has a ring shape with a circular upper surface, and a minute protrusion 31d is formed at substantially the center of the upper surface. The minute protrusion 31d has a square shape in cross section, and has a ring shape formed within the ring width of the upper cylindrical portion 31c.

All the positive electrode leads 11 b 1 of the positive electrode sheet 11 are welded to the upper cylindrical portion 31 c of the positive electrode current collecting member 31. That is, as illustrated in FIG. 3, the positive electrode lead 11 b 1 is overlapped and joined to the upper cylindrical portion 31 c of the positive electrode current collecting member 31. Since each positive electrode lead 11b1 is very thin, a large current cannot be taken out by one. For this reason, a large number of positive electrode leads 11b1 are formed at predetermined intervals over the entire length from the start of winding to the shaft core 15 to the end of winding.
Since the positive electrode current collecting member 31 is oxidized by the electrolytic solution, the reliability can be improved by forming it with aluminum. As soon as the surface of aluminum is exposed by some processing, an aluminum oxide film is formed on the surface, and this aluminum oxide film can prevent oxidation by the electrolytic solution.
Further, by forming the positive electrode current collecting member 31 from aluminum, the positive electrode lead 11b1 of the positive electrode sheet 11 can be welded by ultrasonic welding or spot welding.

The negative electrode current collecting member 21 (see FIG. 1) is formed of, for example, copper, and has an inner peripheral cylindrical portion 21b that is press-fitted into the outer surface of the shaft core 15 on the shaft core side of the disc-shaped base portion 21a. The outer peripheral cylindrical portion 21c protrudes in the same direction as the inner peripheral cylindrical portion 21b.
All of the negative electrode leads 12b1 of the negative electrode sheet 12 are welded to the outer peripheral cylindrical portion 21c of the negative electrode current collecting member 21 by ultrasonic welding or spot welding. Since each negative electrode lead 12b1 is very thin, a large number of negative leads 12b1 are formed at predetermined intervals over the entire length from the start of winding to the shaft core 15 to take out a large current.

The negative electrode lead 12b1 of the negative electrode sheet 12 and the ring-shaped pressing member 22 are welded to the outer periphery of the outer peripheral cylindrical portion 21c of the negative electrode current collecting member 21. Since there are a large number of the negative electrode leads 12b1, they are brought into close contact with the outer periphery of the outer peripheral cylindrical portion 21c of the negative electrode current collecting member 21, and the holding member 22 is wound around the outer periphery of the negative electrode lead 12b1 to be temporarily fixed and welded in this state.
A copper negative electrode conducting lead 22 is welded to the lower surface of the negative electrode current collecting member 21.
The negative electrode conducting lead 23 is welded to the battery container 2 at the bottom of the battery container 2. The battery container 2 is formed of, for example, carbon steel having a thickness of 0.5 mm, and the surface thereof is plated with nickel. By using such a material, the negative electrode energizing lead 23 can be welded to the battery container 2 by resistance welding.

FIG. 6 is an enlarged view of the area A of the cylindrical battery 1 shown in FIG. In the following description, please refer to FIG. 6 together with FIG. 1 and FIG.
The positive electrode lead 11b1 of the positive electrode sheet 11 and the ring-shaped pressing member 32 are welded to the outer periphery of the upper cylindrical portion 31c of the positive electrode current collecting member 31. Since there are many positive electrode leads 11b1, they are brought into close contact with the outer periphery of the upper cylindrical portion 31c of the positive electrode current collecting member 31, and the holding member 32 is wound around the outer periphery of the positive electrode lead 11b1 and temporarily fixed, and welding is performed in this state.
A large number of positive leads 11 b 1 formed on the positive electrode sheet 11 constituting the electrode group 10 are welded to the upper cylindrical portion 31 c of the positive electrode current collector 31, so that the positive electrode current collector 31 is integrated with the electrode group 10. Composed.

  A first flexible connection member 33 formed by laminating a number of aluminum foils is joined to the upper surface of the base portion 31a of the positive electrode current collecting member 31 by welding a part thereof. The first flexible connecting member 33 can flow a large current by laminating and integrating a large number of aluminum foils, and is provided with flexibility. In other words, it is necessary to increase the thickness of the connecting member in order to pass a large current, but if it is formed of a single metal plate, the rigidity increases and the flexibility is impaired. Therefore, a large number of aluminum foils having a small thickness are laminated to give flexibility. The reason why the first flexible member 33 is required to be flexible will be described later.

As shown in FIG. 3, a ring-shaped insulating plate 41 made of an insulating resin material having a circular opening 41 a is mounted on the upper cylindrical portion 31 c of the positive electrode current collecting member 31.
The insulating plate 41 has an opening 41a and a side portion 41b protruding downward.
An aluminum inner lid 35 is fitted in the opening 41 a of the insulating material 41. A part of the second flexible connecting member 34 is welded to the inner lid 35 on the lower surface of the inner lid 35. The second flexible member 34 can flow a large current by laminating and integrating a large number of aluminum foils, and is provided with flexibility.

As shown in FIG. 3, the first flexible connecting member 33 and the second flexible connecting member 34 are fixed at one end side by welding, as shown in FIG. 3, before the electrolyte is injected into the battery container 2. The other end side is an open end. After injecting the electrolytic solution, the open ends of the first flexible connecting member 33 and the second flexible connecting member 34 are welded together as shown in FIG.
An opening 36 for welding the first flexible member 33 and the second flexible member 34 is formed in the inner lid 35.

  Above the inner lid 35, there is disposed a cleavage valve 37 made of aluminum or the like whose peripheral portion is placed on the insulating plate 41 and whose central portion is in contact with the upper surface of the inner lid 35. The cleavage valve 37 has a cut 37a. The cleavage valve 37 is provided for ensuring the safety of the battery. When the internal pressure of the lithium battery increases, the cleavage valve 37 warps upward and is separated from the inner lid 35 to cut off the current supply as the first stage. As a second stage, when the internal pressure still rises, it has a function of cleaving at the cut 37a and releasing the internal gas.

  The insulating plate 41 described above is interposed between the outer peripheral portion of the inner lid 35 and the peripheral edge side of the cleavage valve 37, so that only the central portion of the cleavage valve 37 is in contact with the inner lid 35 in the initial state. Small protrusions 31 d formed on the upper surface of the upper cylindrical portion 31 c of the positive electrode current collecting member 31 bite into the lower surface of the insulating plate 41. The positive electrode current collecting member 31 is integrated with the electrode group 10 including the negative electrode current collecting member 21 welded to the bottom surface of the battery container 2 via the shaft core 15. For this reason, the insulating plate 41 into which the minute protrusions 31d of the positive electrode current collecting member 31 have been bitten is held against an external force such as impact or vibration acting perpendicularly to the axial direction.

A lid 3 is disposed on the upper surface of the cleavage valve 37. The lid 3 is made of iron such as carbon steel, and has a hat shape having a disc-shaped peripheral portion 3a that contacts the cleavage valve 37 and a headless and bottomless cylindrical portion 3b that protrudes upward from the peripheral portion 3a. Have. A plurality of openings 3c are formed in the cylindrical portion 3b.
The upper and lower surfaces and outer peripheral side surfaces of the peripheral edge 3 a of the lid 3 are covered with the peripheral edge of the cleavage valve 37. The cleavage valve 37 is initially formed in a shape having a side wall 37b standing perpendicular to the disc-shaped base as shown in FIG. 3, and after the peripheral edge 3a of the lid 3 is mounted, It is caulked by a press or the like, bent into a U shape, and covers the upper surface side of the peripheral edge 3 a of the lid 3.
In addition, when the lid | cover 3 is formed with iron, when joining in series with another cylindrical battery, it can join by another cylindrical battery formed with iron by spot welding.

A gasket 43 is provided to cover the upper and lower surfaces and the outer peripheral surface of the peripheral edge of the cleavage valve 37. As shown in FIG. 3, the gasket 43 initially includes an outer peripheral wall 43 b that is erected upward on the peripheral edge of the ring-shaped base 43 a, and an inner peripheral side that extends downward from the base 43 a. And a cylindrical portion 43c that is formed to hang substantially perpendicularly.
As will be described in detail later, the outer peripheral wall portion 43b of the gasket 43 is bent by a press or the like, and is processed so as to press the cleavage valve 37 and the lid 3 in the axial direction by the base portion 43a and the outer peripheral wall portion 43b. . Thereby, the electrode group 10 integrated with the positive electrode current collecting member 31 is firmly held in the axial direction.

A predetermined amount of non-aqueous electrolyte is injected into the battery container 2. As an example of the non-aqueous electrolyte, six electrolytes may be used in a mixed organic solvent in which ethylene carbonate (EC), dimethyl carbonate (DMC), and diethyl carbonate (DEC) are mixed at a volume ratio of 1: 1: 1. An example is one obtained by dissolving 1 mol / liter of lithium fluorophosphate (LiPF ₆ ).
Hereinafter, an example of a manufacturing method of the cylindrical battery having the above-described configuration will be described.

-Manufacturing method of cylindrical battery-
A positive electrode sheet 11 having a positive electrode processing part 11a and a positive electrode unprocessed part 11b on which a large number of positive electrode leads 11b1 are formed is produced. Further, the negative electrode sheet 12 on which the negative electrode processing part 12a and a large number of negative electrode leads 12b1 are formed is prepared.
The electrode group 10 is produced by winding the positive electrode sheet 11 and the negative electrode sheet 12 around the shaft core 15 with the separator 13 between the two sheets.

  A negative electrode current collecting member 21 is attached to the lower portion of the shaft core 15 of the electrode group 10. The negative electrode current collector 21 is attached by fitting the inner peripheral cylinder portion 21 b of the negative electrode current collector 21 into the outer periphery of the shaft core 15. The negative electrode lead 12b1 is distributed almost uniformly over the entire periphery of the outer peripheral cylindrical portion 21c of the negative electrode current collecting member 21, and the presser member 22 is fitted to the outer periphery of the negative electrode lead 12b1. Then, the negative electrode lead 12b1 and the presser ring 22 are welded to the negative electrode current collecting member 21 by ultrasonic welding or the like.

  A positive electrode current collecting member 31 having one end of the first flexible connecting member 33 welded to the upper surface side is attached to the upper portion of the shaft core 15. Spot welding can be used for welding of the first flexible connecting member 33 and the positive electrode current collecting member 31. The positive current collector 31 is attached to the shaft core 15 by fitting the lower cylindrical portion 31 b of the positive current collector 31 to the inner surface of the shaft 15.

  The positive electrode lead 11b1 is distributed almost uniformly around the entire periphery of the upper cylindrical portion 31c of the positive electrode current collecting member 31, and the presser member 32 is fitted to the outer periphery of the positive electrode lead 11b1. Then, the positive electrode lead 11b1 and the presser ring 32 are welded to the positive electrode current collecting member 31 by ultrasonic welding or the like. In this way, the power generation unit 20 illustrated in FIG. 3 is produced.

The power generation unit 20 produced through the above-described steps is accommodated in a metal bottomed cylindrical member having a size that can accommodate the power generation unit 20. Although it is not necessary to add, the bottomed cylindrical member is the battery container 2.
Hereinafter, in order to simplify and clarify the description, this bottomed cylindrical member will be described as the battery container 2.
The negative electrode conducting lead 22 of the power generation unit 20 housed in the battery container 2 is welded to the battery container 2 by resistance welding.
Next, the battery container 2 is drawn, a part of the battery container 2 protrudes inward, and a substantially V-shaped groove 2a is formed on the outer surface.
The groove 2 a of the battery container 2 is formed so as to be positioned in the upper end portion of the power generation unit 20, in other words, in the vicinity of the upper end portion of the positive electrode current collecting member 31.

A predetermined amount of electrolyte is injected into the battery container 2 in which the power generation unit 20 is accommodated.
When injecting the electrolytic solution, the first flexible connecting member 33 is bent at a position that does not interfere with the injection. Further, after the injection of the electrolytic solution is finished, it is deformed and its open end is arranged at a position corresponding to the opening 36 of the inner lid 35.

An inner lid 35 to which one end of the second flexible connecting member 34 is welded is attached to the insulating plate 41 and disposed on the positive electrode current collecting member 31. Spot welding can be used for welding the second flexible connecting member 34 and the inner lid 35. The inner lid 35 and the insulating plate 41 are attached by press fitting, welding, adhesion, or the like. The insulating plate 41 to which the inner lid 35 is attached is disposed on the positive electrode current collecting member 31 in a state where the inner surface of the upper cylindrical portion 31c of the positive electrode current collecting member 31 is fitted into the side portion 41b of the insulating plate 41. The current collecting member 31 is placed on a minute protrusion 31d formed on the upper surface of the upper cylindrical portion 31c.
The open end portion of the second flexible connection member 34 is positioned at a position corresponding to the opening portion 36 of the inner lid 35 and overlapped with the open end portion of the first flexible connection member 31.

The open ends of the first flexible connecting member 33 and the second flexible connecting member 34 are welded together by spot welding.
When welding the first flexible connection member 33 and the second flexible connection member 34, as described above, the first flexible connection member 33 and the second flexible connection member 34 are deformed in order to displace the positions of the respective open ends. However, since each is formed by laminating a plurality of thin metal foils such as aluminum foils, it has sufficient flexibility for deformation.

Next, the lid 3 to which the cleavage valve 37 is fixed is placed on the insulating plate 41. The cleavage valve 37 and the lid 3 are fixed by caulking or the like. As shown in FIG. 3, since the side wall 37 b is initially formed perpendicular to the base portion 37 a in the cleavage valve 37, the peripheral edge portion 3 a of the lid 3 is disposed in the side wall 37 b of the cleavage valve 37. Then, the side wall 37b of the cleavage valve 37 is deformed by a press or the like so as to cover the upper and lower surfaces and the outer peripheral side surface of the peripheral edge of the lid 3 and press-contact.
Thereafter, the lid 3 and the battery container 2 are crimped, and the gasket 3 holds the lid 3, in other words, the positive electrode current collecting member 31 and the electrode group 10 in the axial direction, and the positive electrode current collecting member 31 is set in the axial direction. Processing to ensure that the vertical direction is maintained.
The method will be described with reference to FIGS. 4 to 6 showing an enlarged cross section of the region A shown in FIG.

As shown in FIG. 4, a gasket 43 is disposed between the lid 3 to which the cleavage valve 37 is fixed by caulking and the battery container 2. The gasket 43 is formed of rubber and is not intended to be limited, but an example of one preferred material is ethylene propylene copolymer (EPDM). For example, when the battery container 2 is made of carbon steel having a thickness of 0.5 mm and the outer diameter is 40 mmΦ, the thickness of the gasket 43 is about 10 mm.
In the state illustrated in FIG. 4, the gasket 43 remains inside the groove 2 a of the battery container 2. In addition, the position of the upper end of the power generation unit 20 corresponds to the upper part of the groove 2 a of the battery container 2.
Further, the minute protrusions 31 d formed on the upper surface of the upper cylindrical portion 31 c of the positive electrode current collecting member 31 are arranged corresponding to the lower surface of the insulating plate 41.

  As described above, the gasket 43 is initially formed in a shape having the outer peripheral wall portion 43b above the base portion 43a on the ring and the cylindrical portion 43c projecting downward in the vertical direction to the base portion 43a. The outer peripheral wall 43b is also formed so as to protrude in a substantially vertical direction with respect to the base 43a.

As shown in FIG. 4, with the lid 3 on which the cleavage valve 37 is caulked mounted on the gasket 43, as shown in FIG. The molding die 61 is pushed down in the axial direction of the battery container 2, and the outer peripheral wall 43 b of the gasket 43 is inclined inward along with the upper side edge of the battery container 2.
The press working may be performed a plurality of times by changing from a press surface whose inclination is nearly vertical to a molding die whose inclination is gradually lowered so as to approach the horizontal.
As the pressing process proceeds, the minute protrusions 31 d formed on the upper surface of the upper cylindrical portion 31 c of the positive electrode current collecting member 31 approach the lower surface of the insulating plate 41.

  FIG. 6 shows a state after caulking the lid 3 and the gasket 43 by using a molding die 62 having a horizontal press surface. In this step, a molding die 63 inclined at substantially the same angle as the inclined surface of the groove 2 a is disposed in the groove 2 a of the battery container 2, and the cleavage valve 37 is caulked between the molding dies 62 and 63. The lid 3 is caulked by compressing the gasket 43 and the upper side edge of the battery container 2 in the axial direction. In this step, the molding die 63 is initially disposed at a position separated from the upper outer surface 2 b in the groove 2 a of the battery container 2.

  For this reason, the upper side of the groove 2 a of the battery container 2 is pushed downward as the molding die 62 is pushed down. And the outer surface 2b in the groove | channel 2a of the battery container 2 contact | abuts to the shaping die 63, and the outer peripheral wall of the gasket 43 arrange | positioned between the battery container 2 and the outer peripheral part 3a of the lid | cover 3 where the cleavage valve 37 was crimped. The portion 43b is bent in an L shape along the upper surface and outer peripheral side surface of the cleavage valve 37. In this way, the lid 3 is held by the battery container 2 and the gasket 43, whereby the positive electrode current collecting member 31 and the electrode group 10 are firmly held in the direction perpendicular to the axial direction.

Here, the height H _plate from the lower surface of the base portion 31a of the positive electrode current collecting member 31 (the contact surface with the upper surface of the shaft core 15 in FIG. 1) to the minute protrusion 31d is from the upper surface of the shaft core 15 to the insulating plate 41. The dimension is larger than the height H _space to the lower surface. That is, the relationship of H _plate > H _space is satisfied. For this reason, the upper side of the groove 2a of the battery container 2 is pushed downward, and a large pressure is applied in the axial direction by the press, whereby the minute protrusion 31d of the positive electrode current collecting member 31 is pressed against the insulating plate 41, A part of it bites into the insulating plate 41. Further, the base 31a of the positive electrode current collecting member 31 is deformed so as to bend downward somewhat.
Therefore, the electrode group 10 integrated with the positive current collecting member 31 is firmly held by the insulating plate 41 and the positive current collecting member 31 against external forces such as impact and vibration acting perpendicular to the axial direction. Is done.
The minute protrusion 31d of the positive electrode current collecting member 31 may be configured to hold the electrode group 10 against an external force acting in a direction perpendicular to the axial direction by strongly pressing against the insulating plate 41. It is not essential that the minute protrusion 31d is bitten into the insulating plate 41. However, a large holding force can be obtained if at least a part of the minute protrusion 31d is bitten into the insulating plate 41.

As described above, according to the above-described embodiment, the battery container 2 and the gasket 43 are caulked with the peripheral edge portion 3a of the lid 3 interposed therebetween, so that the positive electrode current collecting member 31 is integrated against the external force acting in the axial direction. The held electrode group 10 is firmly held. Further, the minute projection 31d of the positive electrode current collecting member 31 is pressed against the insulating plate 41, so that the electrode group 10 integrated with the positive electrode current collecting member 31 against the external force acting in the direction perpendicular to the axial direction is provided. Hold firmly.
In the above embodiment, the shape of the minute protrusion 31d of the positive electrode current collecting member 31 can be variously modified as described below.

(Embodiment 2)
9 is an external perspective view showing Embodiment 2 of the positive electrode current collecting member, and FIG. 10 is a cross-sectional view taken along the line XX of FIG.
In the second embodiment, the minute projection 31d formed on the upper surface of the upper cylindrical portion 31c of the positive electrode current collecting member 31 has a semicircular cross section. That is, a minute protrusion 31d having a semicircular cross section is formed in a ring shape within the width of the ring of the upper cylindrical portion 31c of the positive electrode current collecting member 31. Even in the case of such an embodiment, the electrode group 10 integrated with the positive electrode current collecting member 31 is strengthened against the external force acting perpendicularly to the axial direction by causing the minute protrusion 31d to bite into the insulating plate 41. Can be held in.

(Embodiment 3)
11 is an external perspective view showing Embodiment 2 of the positive electrode current collecting member, and FIG. 12 is a cross-sectional view taken along line XII-XII in FIG.
In the third embodiment, a cut is made in the upper side surface of the upper cylindrical portion 31c of the positive electrode current collecting member 31, and the upper side of the cut is lifted and inclined so as to rise from the back of the cut portion toward the surface. It is a thing. That is, by cutting from the side surface of the ring of the upper cylindrical portion 31c of the positive electrode current collecting member 31, a portion on the upper surface side of the upper cylindrical portion 31c is projected in a ring shape. Even in the case of such an embodiment, the minute protrusion 31d is bitten into the insulating plate 41, and the electrode group 10 integrated with the positive electrode current collecting member 31 is strengthened against an external force acting perpendicularly to the axial direction. Can be held in.

Table 1 shows the number of internal short-circuit occurrences after the vibration test was performed on the cylindrical batteries of Embodiments 1 to 3.
The first to third embodiments each have the structure of the cylindrical battery illustrated in FIG. 1, and only the minute protrusion 31 d formed on the upper cylindrical portion 31 c of the positive electrode current collecting member 31 is included in each of the above embodiments. The shape shown was used. Further, as a comparative example, a gap is provided between the positive electrode current collecting member 31 and the insulating plate 41, in other words, a relationship of H _plate <H _space is satisfied (however, H _plate is a positive electrode current collecting member) 31 is a height from the contact surface with the upper surface of the shaft core 15 to the minute protrusion 31d, and H _space is a height from the upper surface of the shaft core 15 to the lower surface of the insulating plate 41). On the other hand, the result of the same vibration test is posted.

The vibration test is in accordance with “JISC8713 sealed small secondary battery mechanical test” with a vibration frequency of 10 to 500 Hz, an amplitude of 0.35 mm peak or a maximum of 50 m / s ² , and the vibration axis is a cylinder whose effect is easy to verify. The direction perpendicular to the longitudinal (axis) direction was taken. The sweep rate was 1 octave / minute and repeated up to 100 cycles. The voltage was measured every 20 cycles to check for the presence of internal short circuits, and the number of internal short circuits in each battery was counted. The battery voltage was initially 2.7 V, the battery voltage was measured every 20 cycles, and the battery whose battery voltage was 2.5 V or less was regarded as an internal short circuit. In the test, 20 batteries were used for each example. The ambient temperature is 20 + 0.5 ° C to 20-0.5 ° C. The number of internal short-circuit occurrences shown in Table 1 is a cumulative number.

  As listed in Table 1, in the comparative example, a battery in which an internal short circuit occurred from 40 cycles was confirmed, and at the end of 100 cycles, an internal short circuit occurred in a total of 5 batteries. On the other hand, in all of the embodiments of the present invention, in all of 1 to 3, no battery has caused an internal short circuit until 60 cycles, and 2 batteries have undergone an internal short circuit at the end of 100 cycles. It was less than the number. Therefore, in any of the embodiments, it was confirmed that the reliability was improved with respect to the comparative example.

  According to the above embodiment, the electrode group integrated with the positive electrode current collecting member 31 against the external force acting in the axial direction by caulking the battery container 2 and the gasket 43 with the peripheral edge portion 3a of the lid 3 interposed therebetween. 10 is held firmly. In addition, the minute projection 31d of the positive electrode current collecting member 31 is pressed against the insulating plate 41, so that the electrode group 10 integrated with the positive electrode current collecting member 31 against an external force acting in a direction perpendicular to the axial direction. Hold firmly.

(Embodiment 4)
In addition, the minute protrusion 31d formed on the positive electrode current collecting member 31 can be variously modified and implemented in addition to the above embodiment.
13 is an external perspective view showing Embodiment 4 of the present invention, and FIG. 14 is a sectional view taken along line XIV-XIV in FIG.
In the fourth embodiment, the minute protrusion 31d formed on the upper surface of the upper cylindrical portion 31c of the positive electrode current collecting member 31 has a triangular cross section. That is, a minute protrusion 31d having a triangular cross section is formed in a ring shape within the width of the ring of the upper cylindrical portion 31c of the positive electrode current collecting member 31. Even in the case of such an embodiment, the minute protrusion 31d is bitten into the insulating plate 41, and the electrode group 10 integrated with the positive electrode current collecting member 31 is strengthened against an external force acting perpendicularly to the axial direction. Can be held in.

  In each of the above embodiments, each of the minute protrusions 31d formed on the positive electrode current collecting member 31 has a continuous shape in a ring shape. However, the minute protrusions 31d may be formed with a predetermined pitch. Alternatively, only a few may be provided at appropriate positions. Even in the case of providing continuously or discretely, the thickness of the minute protrusion 31d may be the same as that of the upper cylindrical portion 31c of the positive electrode current collecting member 31. The minute protrusions 31d may be arranged not only on the same circumference but also concentrically on a plurality of circumferences. Each minute protrusion 31d may be formed so as to have a different shape and orientation. The upper cylindrical portion 31c of the positive electrode current collecting member 31 may be formed in a triangular shape that is gradually inclined from the base portion 31a side toward the distal end side, and a part of the distal end side may have a function of a minute protrusion 31d. .

  In the above embodiment, the case of a lithium battery has been described. However, the present invention is not limited to a lithium battery, and may be applied to other cylindrical batteries such as a nickel metal hydride battery and a nickel cadmium battery. Can do.

  In the above embodiment, the case where the positive electrode current collecting member 31 is held by the gasket is shown. However, the negative electrode current collecting member can be held by the gasket. In a cylindrical battery having a current collecting member as a negative electrode, a lid connected to the negative electrode current collecting member is formed of an iron material such as carbon steel, and a battery container as a positive electrode is formed of aluminum. That is, in FIG. 1, the lead (positive electrode) 12b1, the current collecting member (positive electrode) 21, the current collecting lead (positive electrode) 22 and the battery container 2 are formed of aluminum, and the (negative electrode) lead 11b1 is formed of copper. The member (negative electrode) 31, the inner lid 35, the cleavage valve 37, and the lid 3 are formed of iron such as carbon steel. The lid 3 may be formed of aluminum. However, even in this case, the material is an example, and the material formed of other materials is also included in the present invention.

When the current collecting member 31 is a negative electrode, a minute protrusion 31 d is formed on the current collecting member 31. The shape or the like of the minute protrusion 31d can be applied to any of the above-described embodiments.
In addition, the cylindrical battery of the present invention can be variously modified and configured within the scope of the invention. In short, the positive electrode and the negative electrode are wound around the shaft core via the separator. Accommodates an electrode group, a pair of current collecting members disposed on one end side and the other end side in the axial direction of the electrode group, and connected to one and the other of the positive electrode and the negative electrode, respectively, and the electrode group and the pair of current collecting members A battery container connected to one of the pair of current collecting members, a lid connected to the other of the pair of current collecting members, and an insulating member disposed between the other of the pair of current collecting members and the lid; A rubber gasket interposed between the outer peripheral edge of the lid and one side edge in the axial direction of the battery container and fixed by a pressure contact force acting in the axial direction of the outer peripheral edge of the battery container. The current collecting member is pressed against the insulating member and resists external forces acting in the direction perpendicular to the axial direction. The electrode group may be one which holds Te.

DESCRIPTION OF SYMBOLS 1 Cylindrical battery 2 Battery container 2a Groove 3 Lid 3a Peripheral part 3b Cylindrical part 10 Electrode group 11 Positive electrode sheet (positive electrode)
11a Positive electrode processing part 11b Positive electrode non-processing part 11b1 Positive electrode lead 12 Negative electrode sheet (negative electrode)
12a Negative electrode processing part 12b Negative electrode unprocessed part 12b1 Negative electrode lead 13 Separator 15 Core 20 Power generation unit 21 Negative electrode current collecting member 31 Positive electrode current collecting member 31a Base part 31b Lower cylinder part 31c Upper cylinder part 31d Small protrusion 35 Inner lid 37 Cleavage valve 41 Insulating plate 43 Gasket 43a Base 43b Outer peripheral wall 43c Tube

Claims (5)

An electrode group in which a positive electrode and a negative electrode are wound around an axis through a separator;
A pair of current collecting members disposed on one end side and the other end side in the axial direction of the electrode group, respectively connected to one and the other of the positive electrode and the negative electrode;
A battery container containing the electrode group and the pair of current collecting members and connected to one of the pair of current collecting members;
A lid connected to the other of the pair of current collecting members;
An insulating member disposed between the other of the pair of current collecting members and the lid;
A rubber gasket interposed between the outer peripheral edge of the lid and one side edge in the axial direction of the battery container and fixed by a pressing force acting in the axial direction of the outer peripheral edge of the lid and the battery container; ,
And the current collecting member is pressed against the insulating member and holds the electrode group against an external force acting in a direction perpendicular to the axial direction.   2. The cylindrical battery according to claim 1, wherein the current collecting member has a minute protrusion on an upper part thereof.   3. The cylindrical battery according to claim 2, wherein at least a part of the minute protrusions of the current collecting member bites into the insulating member.   4. The cylindrical battery according to claim 2, wherein the current collecting member has a base portion and a cylindrical portion rising from the base portion toward the insulating plate, and the minute protrusions are formed on the current collecting member. The cylindrical battery is characterized in that it is formed on the upper surface of the cylindrical portion with a thickness smaller than the thickness of the cylindrical portion. 5. The cylindrical battery according to claim 4, wherein the minute protrusions are continuously formed in a ring shape on the upper surface of the cylindrical portion.