JP2010277785A - Sealed battery and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sealed battery equipped with a sealing body with a safety valve excellent in conductivity. <P>SOLUTION: The manufacturing method of a sealed battery sealed by caulking-fixing of a sealing body on an opening of a bottomed cylindrical outer can includes: a step for preparing a terminal cap equipped with an external terminal part made of an iron system material and projecting outside of the battery, a flange part located on a circumference of the external terminal part, and a spot facing hole provided on the flange part and having a tapered part; a step for preparing a safety valve (3) which is made of an aluminum system material and is provided with a conductive contact part (3a) projecting inside the battery, a peripheral part (3b) located at a circumference of the conductive contact part (3a), and an arch-shaped projection (3c) in a plan-view provided on the peripheral part (3b); and a rivet-fixing step for engaging the projection (3c) into the spot facing hole, crushing a tip end portion of the projection (3c), and rivet-fixing the projection (3c) and the spot facing hole. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a sealed battery and a method for manufacturing the same, and more particularly to improving the conductivity of a sealed battery provided with a sealing body with a safety valve.

  Nonaqueous electrolyte secondary batteries have high energy density and high capacity, and are therefore widely used as drive power sources for portable devices and electric tools.

  Since nonflammable secondary batteries use flammable organic solvents as electrolytes, it is required to ensure the safety of the batteries. For this reason, a current interrupting mechanism that operates when the battery internal pressure rises is incorporated into a sealing body that seals the battery.

  FIG. 8 shows a conventional sealed battery provided with a sealing body incorporating a current interruption mechanism. As shown in FIG. 8, the sealing body 10 includes a terminal cap 5, a safety valve 3 positioned on the battery inner surface of the terminal cap, a terminal plate 1 positioned on the battery inner surface of the safety valve, the safety valve 3, and the terminal plate 1. And an insulating plate 2 that separates and insulates.

  The operation of the current interruption mechanism of the sealed battery will be described. When the battery internal pressure rises, the recess (energizing contact portion) protruding toward the inside of the battery of the safety valve 3 is deformed so as to swell toward the outside of the battery. When the battery internal pressure continues to rise, the terminal plate 1 connected to the energizing contact portion of the safety valve 3 is broken, and the current supply to the terminal cap 5 is interrupted.

  In such a current interruption mechanism, the above-described operation needs to be performed smoothly in the safety valve, and a material that is easily deformable is required. On the other hand, since the terminal cap faces the external environment, the material is required to have a certain strength. For this reason, an iron-based material (iron or iron alloy) is used for the terminal cap, and an aluminum-based material (pure aluminum and aluminum alloy) is used for the safety valve.

  By the way, the battery temperature of the non-aqueous electrolyte secondary battery used for the purpose of discharging with a large current such as an electric tool may become a high temperature of 80 ° C. or higher during discharging. When the battery is repeatedly exposed to high temperatures, the elasticity of resin parts such as the insulating plate 2 and the gasket 30 is lost. If the elasticity of the resin parts is lost, the pressing force between the terminal cap 5 and the safety valve 3 sandwiched between the resin parts decreases, so that the contact is loosened and the internal resistance of the battery increases or becomes unstable. It becomes. Therefore, it is necessary to securely fix the terminal cap 5 and the safety valve 3.

  The following patent document 1 is mentioned as a technique regarding fixation of the terminal cap part of a battery.

Japanese Patent Publication No. 5-74904

  Patent Document 1 discloses a battery cap having a cylindrical portion and a flange portion provided on the outer periphery of the cylindrical portion, and a plurality of convex portions having a protruding height larger than the plate thickness of the battery cap. The battery cap hole is fitted into the convex portion of the metal plate, and the end surface of the convex portion of the metal plate protruding from the hole of the battery cap is pressed to fix both. A battery cap assembly is disclosed.

  An object of the present invention is to provide a sealed battery in which a terminal cap forming a sealing body and a safety valve are securely fixed, and high conductivity can be maintained.

  The present invention provides a sealed battery and a method for manufacturing the same to solve the above problems. The manufacturing method of the present invention is a manufacturing method of a sealed battery in which a sealing body is caulked and sealed in an opening of a bottomed cylindrical outer can, and is made of an iron-based material and protrudes outward from the battery. A terminal cap having a flange portion located at a peripheral edge of the external terminal portion, and a counterbore hole provided in the flange portion and having a large diameter portion on the battery outer surface side and a small diameter portion on the battery inner surface side A terminal cap preparation step for preparing a battery, an energizing contact portion made of an aluminum-based material, projecting inward of the battery, a peripheral portion located at a periphery of the energizing contact portion, and provided in the peripheral portion in plan view A safety valve preparing step for preparing a safety valve having an arch-shaped protrusion, and the protrusion of the safety valve is fitted into the counterbore hole of the terminal cap, the tip of the protrusion is crushed, and the protrusion and the counterbore hole are removed. And riveting steps of Tsu bets fixed, characterized in that it comprises a. The sealed battery of the present invention is a sealed battery in which a sealing body (10) is caulked and sealed in an opening of a bottomed cylindrical outer can (20), and the sealing body (10) is a battery. External terminal portion (5a) protruding outward, flange portion (5b) located at the periphery of the external terminal portion (5a), and large diameter on the battery outer surface side provided on the flange portion (5b) Terminal cap (5) having a countersunk portion and a small-diameter portion on the inner side of the battery, a terminal cap (5a) protruding inward of the battery, and a peripheral edge of the power supply contact portion (3a) A safety valve (3) having a peripheral portion (3b) located at the top and an arch-shaped protrusion (3c) provided in the peripheral portion (3b) in plan view, the protrusion (3c) of the safety valve The terminal cap is fitted in a counterbore hole (5c), and the protrusion (3c It is crushed tip of the a projection (3c) and said counterbore (5c) is characterized in that it is riveting.

  As shown in FIG. 6A, the “arch shape” in this specification refers to a planar shape obtained by cutting off a part of an annulus sandwiched between two concentric circles having different radii. Further, the “arch-shaped protrusion” in this specification refers to a protrusion having an arch shape in plan view.

  With such a shape, the area of the caulking portion is larger than in the case of the conventional pin-shaped protrusion, and stable rivet fixing is obtained, which is preferable.

  The size of the protrusion is preferably 0.1 to 0.2 times the width of the safety valve radius, and the arch has a length of 15 ° to 50 ° with respect to the virtual circumference of the arch. It is preferable that If the protrusion is smaller than this range, the effect of the present application is reduced, and if the protrusion is larger, there is a possibility that inconvenience may occur in manufacturing.

  According to a second aspect of the present invention, the small-diameter portion of the counterbore has a tapered portion (see 5d in FIG. 3) having a large opening area on the battery inner surface side and a decreasing opening area toward the outside of the battery. Features.

  Here, the counterbore hole means a stepped hole having a large diameter portion and a small diameter portion, as indicated by 5c in FIG. According to this configuration, the rivet can be conveniently fixed using the stepped portion of the counterbore hole.

  In manufacturing, an R portion as shown in FIG. 4A is generated at the base of the side surface of the protrusion. When this protrusion is fitted in a normal counterbore hole, the R portion of this protrusion and the lower end of the counterbore hole come into contact with each other, and thus a gap (g) is formed at this portion (see FIG. 4A). For this reason, at the time of compression at the time of battery caulking, the force to fill this gap acts on the rivet caulking portion, the contact pressure between the safety valve and the terminal cap is reduced, and the electric resistance is increased, which is not preferable.

  However, by providing a tapered portion in the counterbore hole, the above gap does not occur, and an increase in battery resistance in this portion can also be prevented (see FIG. 4B).

  As shown in FIG. 5, rivet caulking is performed by inserting the protrusion into a counterbore hole and pressing the tip of the protrusion to fix the rivet.

  A third aspect of the present invention is characterized in that a plurality of the protrusions and the counterbore holes are provided.

  By providing a plurality of the protrusions and counterbores, it is possible to prevent the terminal cap and the safety valve from rotating after rivet fixation. In addition, when a plurality of crimps are fixed by the protrusions and the counterbore holes, the fixing effect is further enhanced. However, if the number of protrusions is too large, the caulking process and the welding process become complicated, so 2 to 4 are preferable. It is preferable that the plurality of arch-shaped protrusions are provided uniformly distributed on the safety valve because the terminal cap and the safety valve are fixed stably.

  According to a fourth aspect of the present invention, when a plurality of the protrusions are provided, each of the protrusions is located on the same circumference (see FIG. 6A).

  If all the protrusions are on the same circumference, the laser emitting part can be fixed and the terminal cap and safety valve can be rotated on the turntable while the joint is fixed with rivets. Can be improved. The plurality of arch-shaped protrusions may be part of arches having different radii, and the effects of the present application can be exhibited even if all the arch-shaped protrusions do not exist on the same circumference.

  According to a fifth aspect of the present invention, after the rivet fixing step, a welding step is performed in which a high energy ray is applied to the terminal cap in the vicinity of the rivet fixing portion to perform welding. By performing welding, more reliable fixation is possible.

  As shown in FIG. 7, the welded portion has a molten and solidified region 9 in which iron, which is a material for a terminal cap, and aluminum, which is a material for a safety valve, are naturally integrated. FIG. 7 shows a state where only the left side in the drawing is irradiated with laser.

  The sixth aspect of the present invention is characterized in that the high energy beam is a laser. Use of a laser is preferable because energy control is easy and accurate welding can be performed.

  Here, in the welding step, the terminal cap of the iron-based material and the safety valve of the aluminum-based material are welded. However, since the melting point and the electric characteristics are greatly different from each other, it is difficult to weld them firmly. . Therefore, it is preferable to irradiate the terminal cap made of an iron-based material having a high melting point with high energy rays for welding. According to this method, the iron-based material having a high melting point of the terminal cap is melted by the high energy wire, and the melted iron-based material flows into the rivet fixing portion located in the vicinity of the irradiation spot, and the thermal energy possessed by the molten iron material. As a result, the aluminum-based material (safety valve protrusion) of the rivet fixing portion is melted, and as a result, the safety valve and the terminal cap are well and firmly welded.

  Furthermore, the welding of the terminal cap and the safety valve may be performed so as to surround the entire outer periphery of the rivet fixing portion, or may be spot welding of one to several points.

  According to the present invention, since the terminal cap and the safety valve can be stably rivet-fixed, it is possible to obtain a sealing body with a safety valve that is excellent in conductivity, and thus, the current extraction efficiency of the sealed battery can be increased. Effects can be obtained.

It is a fragmentary sectional view of the sealed battery of the present invention. It is sectional drawing which shows the terminal cap and safety valve of the sealing body used for the sealed battery concerning this invention. It is a fragmentary sectional view explaining the taper part provided in the counterbore of the terminal cap of this invention. It is a fragmentary sectional view explaining the positional relationship of the counterbore hole of a terminal cap and the projection of a safety valve at the time of caulking with a terminal cap and a safety valve concerning the present invention. FIG. 6 is a cross-sectional view illustrating a process of caulking and fixing a terminal cap and a safety valve in the sealed battery according to the present invention. (A) It is a top view which illustrates one of the safety valves in the sealed battery concerning this invention. (B) It is a perspective view which illustrates one of the safety valves in the sealed battery concerning this invention. In the sealed battery according to the present invention, it is a partial cross-sectional view for explaining welding of a terminal cap and a safety valve. It is a fragmentary sectional view of the conventional sealed battery.

  A mode for carrying out the present invention will be described in detail with reference to the drawings and examples. FIG. 1 is an enlarged cross-sectional view of a main part of the sealed battery according to the present embodiment. In addition, this invention is not limited to the following embodiment and Example. As long as the gist of the invention is not changed, the present invention can be implemented with appropriate modifications.

Embodiment
As shown in FIG. 1, the sealing body 10 used for the sealed battery according to the present embodiment protrudes outward from the battery terminal plate 1 electrically connected to the positive electrode or the negative electrode via the electrode tab 8. The terminal cap 5 having an external terminal portion is interposed between the terminal plate 1 and the terminal cap 5 and is deformed when the internal pressure of the battery rises, thereby interrupting the electrical connection between the terminal plate 1 and the terminal cap 5. And the insulating member 2 that prevents electrical contact between the safety valve 3 and the terminal plate 1 when the safety valve 3 cuts off the current. One electrode of the electrode body 40 and the terminal plate 1 are connected via the electrode tab 8.

  Further, as shown in FIG. 1, the sealing body 10 is caulked and fixed through an insulating gasket 30 to the opening of the outer can 10 containing the electrode body 40 and the nonaqueous electrolyte. The caulking is fixed by riveting with the protrusion 3c of the safety valve 3.

  A method for manufacturing the above lithium ion secondary battery will be described.

<Preparation of positive electrode>
A ratio of 90: 5: 5 in a mass ratio of a positive electrode active material made of lithium cobaltate (LiCoO ₂ ), a carbon-based conductive agent such as acetylene black or graphite, and a binder made of polyvinylidene fluoride (PVdF). These were dissolved in an organic solvent made of N-methyl-2-pyrrolidone, and then mixed to prepare a positive electrode active material slurry.

  Next, using a die coater or a doctor blade, this positive electrode active material slurry was applied to both surfaces of a positive electrode core made of aluminum foil (thickness: 20 μm) with a uniform thickness.

  The electrode plate was passed through a dryer to remove the organic solvent, thereby preparing a dried electrode plate. The dried electrode plate was rolled using a roll press and cut to produce a positive electrode plate.

<Production of negative electrode>
A negative electrode active material made of artificial graphite, a binder made of styrene butadiene rubber, and a thickener made of carboxymethylcellulose are weighed in a mass ratio of 98: 1: 1 and mixed with an appropriate amount of water. A negative electrode active material slurry was prepared.

  Next, using a die coater or a doctor blade, this negative electrode active material slurry was applied to both surfaces of a negative electrode core made of copper foil (thickness: 15 μm) with a uniform thickness.

  The electrode plate was passed through a dryer to remove moisture, and a dried electrode plate was produced. Then, this dry electrode plate was rolled with a roll press and cut to prepare a negative electrode plate.

<Production of electrode body>
The positive electrode, the negative electrode, and a separator made of a polyethylene microporous film were wound with a winder, and an insulating anti-winding tape was provided to complete a wound electrode body.

<Production of sealing body>
First, the terminal cap 5 was produced. The central portion of the nickel-plated 0.5 mm thick iron plate was pressed using a pressing device to form the external terminal portion 5a (convex portion). Next, the flange portion 5b (outer peripheral portion of the convex portion) was formed. An arch-shaped punch hole was made using a jig. Next, press the hole from above with a pressing tool, and further punch the hole again using an arcuate jig that is one size larger. The edge of the hole was tapered. Thereafter, a terminal cap 5 having a counterbore hole having a tapered portion was obtained by punching into a disk shape having a diameter of 16.5 mm.

  Next, the safety valve 3 was produced. The center part of the aluminum plate having a thickness of 0.4 mm was pressed using a pressing device to form an energizing contact part (concave part 3a). Subsequently, the peripheral portion 3b (outer peripheral portion of the convex portion) was pressed from the lower surface using a press instrument, and a projection 3c having a arch shape in plan view was formed as the projection of the present invention (width 1.2 mm × length 5. 0mm x height 0.55mm). Thereafter, the safety valve 3 was obtained by punching into a disk shape having a diameter of 16.5 mm.

  The terminal cap 5 is disposed on the upper surface of the safety valve 3 produced as described above, and the protrusion 3c of the safety valve 3 is fitted into the counterbore hole 5c of the terminal cap 5 (see FIG. 5A). Next, the rivet fixing tools 51a and 51b are used to press from above and below (see FIG. 5 (b)), and the tip of the projection 3c is crushed to form a rivet fixing portion and fix the rivet (FIG. 5 (c)). reference).

  Further, the wall surface of the counterbore hole of the terminal cap near the rivet fixing portion was irradiated with laser (see FIG. 7A), and the rivet fixing portion was welded (see FIG. 7B).

  Finally, an aluminum terminal plate 1 was welded to the lower surface of the safety valve 3 via a polypropylene insulating plate 2 to produce a sealing body 10.

<Preparation of electrolyte>
An electrolyte salt is added to a nonaqueous solvent in which ethylene carbonate (EC), propylene carbonate (PC), and diethyl carbonate (DEC) are mixed at a volume ratio of 1: 1: 8 (when converted to 1 atm and 25 ° C.). The electrolyte solution was obtained by dissolving LiPF ₆ at a rate of 1.0 M (mol / liter).

<Battery assembly>
Weld the negative electrode current collector of the electrode body and the bottom of the cylindrical outer can, inject the electrolyte into the outer can, and connect the terminal plate of the sealing body and the positive electrode current collector through the electrode tab. Electrically connected. Next, the opening of the outer can was caulked using a sealing body 10 via a gasket and sealed, and a cylindrical battery (diameter 18 mm × height 65 mm) according to this embodiment was assembled.

Example 1
A battery according to Example 1 was fabricated according to the above embodiment.

(Example 2)
A battery according to Example 2 was fabricated in the same manner as in the above embodiment except that the rivet fixing part was not irradiated with laser (up to rivet fixing).

(Example 3)
Example 3 is similar to the above embodiment except that the rivet fixing part is not irradiated with laser (the rivet fixing is performed) and the tapered part is not provided in the counterbore hole of the terminal cap. A battery was produced.

(Comparative Example 1)
A battery according to Comparative Example 1 was fabricated in the same manner as in the above embodiment except that the arch-shaped protrusion of the safety valve was changed to a pin-shaped protrusion (φ0.95).

(Comparative Example 2)
A battery according to Comparative Example 2 in the same manner as in the above embodiment except that the arch-shaped protrusion of the safety valve is a pin-shaped protrusion and the rivet fixing portion is not irradiated with laser (the rivet fixing is performed). Was made.

(Comparative Example 3)
Except that the arch-shaped protrusion of the safety valve is a pin-shaped protrusion, the rivet fixing part was not irradiated with laser (the rivet fixing was performed), and the counterbore hole of the terminal cap was not provided with a taper part. A battery according to Comparative Example 4 was produced in the same manner as in the above embodiment.

Table 1 shows the condition settings for each of the above examples and comparative examples.

(Measurement of resistance)
Thirty pieces of each battery produced in the above examples and comparative examples were produced. At this time, after fixing the rivet, after laser welding, and finally sealing the opening of the battery can (hereinafter referred to as “after battery caulking”), the sealing body and the constant current in each process step The battery is charged at 1250 mA (1 It) until the voltage reaches 4.2 V, and then charged at a constant voltage of 4.2 V until the current reaches 62.5 mA (0.05 It). The electrical resistance of the battery seal after storage for a day was measured. The results are shown in Table 2 below. The resistance values shown are the average and variation of the resistance values of 30 batteries, respectively.

（＊）一番左の欄にある記号は、以下を表す。
A：アーチ形状突起 P:ピン形状突起 T：ザグリ穴のテーパ L：レーザ溶接

(*) The symbols in the leftmost column represent the following.
A: Arch shaped protrusion P: Pin shaped protrusion T: Counterbore taper L: Laser welding

  The example and the comparative example were compared and the following consideration was obtained.

<Comparison between Example 1 and Comparative Example 1>
Both counterbored holes had a tapered portion, and laser welding was performed after rivet fixation. The resistance value increased in Comparative Example 1 having pin-shaped protrusions. In particular, at the time of fixing only with rivet caulking before laser welding, Comparative Example 1 was more than three times the resistance value of Example 1, and there was a large variation in resistance value. Moreover, the resistance value was higher in Comparative Example 1 even after laser welding. From these facts, it was found that the terminal cap and the safety valve are sufficiently fixed from the point of fixing the rivet caulking by having the arch-shaped protrusion.

<Comparison between Example 2 and Comparative Example 2>
In both cases, the counterbore holes are tapered, but laser welding was not performed. In Example 2 having arch-shaped protrusions, no increase in resistance value was observed even after battery caulking and after storage. On the other hand, in the comparative example 2 of the pin-shaped protrusion, the resistance increased as it became after rivet caulking, after battery caulking, and after storage. This is considered to be that when the arch-shaped protrusion is not used and laser welding is not performed, the fixing becomes insufficient with time and the resistance value is increased.

<Comparison between Example 3 and Comparative Example 3>
In both cases, the counterbored holes were not tapered and laser welding was not performed. Also in this comparison, it was confirmed that Example 3 having the arch-shaped protrusion had a lower resistance value.

<Comparison between Example 1 and Example 2>
Both the safety valve with the arch-shaped protrusion and the counterbore taper showed a low resistance value with or without laser welding. However, it was found that the laser welded Example 1 was preferable because the resistance value was slightly lower.

In summary, when the other conditions are the same, the resistance value of the example including the arch-shaped protrusion is lower than that of the comparative example including the pin-shaped protrusion. This demonstrates that fixing the terminal cap and the safety valve is improved by changing the protrusion of the safety valve from the pin shape to the arch shape. It has also been found that this fixing can be further improved by laser welding after rivet fixing of the rivet caulking.
(extra content)

As the positive electrode active material used in the nonaqueous electrolyte secondary battery of the present invention, for example, lithium nickelate (LiNiO ₂ ), lithium manganate (LiMn ₂ O ₄ ) phosphate other than lithium cobaltate used in Examples the lithium iron (LiFePO _4), lithium manganese nickel cobalt oxide _{(LiMn x Ni y Co z O} 2, x + y + z = 1), or oxide obtained by replacing part of the transition metal contained in these oxides with other elements such as These lithium-containing transition metal composite oxides can be used alone or in admixture of two or more.

  Examples of the negative electrode material used in the nonaqueous electrolyte secondary battery of the present invention include carbonaceous materials such as natural graphite, artificial graphite, carbon black, coke, glassy carbon, carbon fiber, or a fired body thereof, or the carbonaceous material. And one or more materials selected from the group consisting of lithium, lithium alloys, and metal oxides capable of inserting and extracting lithium can be used.

  The non-aqueous solvent used in the non-aqueous electrolyte secondary battery of the present invention is not limited to the combination of the examples. For example, the solubility of lithium salts such as ethylene carbonate, propylene carbonate, butylene carbonate, and γ-butyrolactone is limited. High dielectric constant solvent, diethyl carbonate, dimethyl carbonate, ethyl methyl carbonate, 1,2-dimethoxyethane, tetrahydrofuran, anisole, 1,4-dioxane, 4-methyl-2-pentanone, cyclohexanone, acetonitrile, propionitrile, It can be used by mixing with a low viscosity solvent such as dimethylformamide, sulfolane, methyl formate, ethyl formate, methyl acetate, ethyl acetate, propyl acetate, ethyl propionate. Furthermore, the high dielectric constant solvent or the low viscosity solvent may be a mixed solvent of two or more.

Examples of the electrolyte salt used in the nonaqueous electrolyte secondary battery of the present invention include LiN (C ₂ F ₅ SO ₂ ) ₂ , LiN (CF ₃ SO ₂ ) ₂ , LiClO, in addition to the LiPF ₆ used in the examples. ₄ or LiBF ₄ or the like may be used alone, or in combination of two or more.

  As described above, according to the present invention, a sealing body with a safety valve excellent in conductivity can be realized, and the current extraction efficiency of a sealed battery equipped with the same can be improved. Therefore, the industrial significance is great.

DESCRIPTION OF SYMBOLS 1 Terminal board 2 Insulation board 3 Safety valve 3a Current supply contact part 3b Peripheral part 3c Protrusion (arch-shaped protrusion)
DESCRIPTION OF SYMBOLS 5 Terminal cap 5a External terminal part 5b Flange part 5c Counterbore hole 5d Counterbore hole taper part 7 Weld part 8 Electrode tab 9 Melting | solidification area 10 Sealing body 20 Exterior can 30 Insulating gasket 40 Electrode body 51 Rivet fixing tool

Claims (10)

In the manufacturing method of the sealed battery in which the sealing body (10) is caulked and sealed in the opening of the bottomed cylindrical outer can (20), the following steps (a) to (c) are provided. Manufacturing method of sealed battery:
(A) an external terminal portion (5a) protruding outward from the battery;
A flange portion (5b) located at the periphery of the external terminal portion (5a);
A counterbore hole (5c) provided in the flange portion (5b) and having a large diameter portion on the battery outer surface side and a small diameter portion on the battery inner surface side;
Preparing a terminal cap (5) having a terminal cap preparation step;
(B) an energizing contact portion (3a) protruding inward of the battery;
A peripheral portion (3b) located at the periphery of the energization contact portion (3a);
An arch-shaped protrusion (3c) provided in the peripheral portion (3b) in plan view;
A safety valve preparation step for preparing a safety valve (3) having: and (c) fitting the protrusion (3c) of the safety valve into the counterbore hole (5c) of the terminal cap, and crushing the tip of the protrusion (3c), A rivet fixing step of rivet fixing the protrusion (3c) and the counterbore hole (5c). In the manufacturing method of the sealed battery according to claim 1,
The small-diameter portion of the counterbored hole has a taper portion where the opening area is wide on the battery inner surface side and the opening area becomes narrower toward the outside of the battery.
A method for producing a sealed battery, comprising: In the manufacturing method of the sealed battery according to claim 1 or 2,
A plurality of the protrusions and counterbore holes are provided,
A method for producing a sealed battery, comprising: In the manufacturing method of the sealed battery according to claim 3,
Each of the protrusions is located on the same circumference;
A method for producing a sealed battery, comprising: In the manufacturing method of the sealed battery according to any one of claims 1 to 4,
After the rivet fixing step, a welding step of irradiating the terminal cap in the vicinity of the rivet fixing portion with high energy rays and welding the terminal cap and the safety valve is added,
A method for producing a sealed battery, comprising: In the manufacturing method of the sealed battery according to claim 5,
The high energy beam is a laser;
A method for producing a sealed battery, comprising: In the sealed battery in which the sealing body (10) is caulked and sealed in the opening of the bottomed cylindrical outer can (20),
The sealing body (10)
An external terminal portion (5a) protruding outward from the battery;
A flange portion (5b) located at the periphery of the external terminal portion (5a);
A counterbore hole (5c) provided in the flange portion (5b) having a large diameter portion on the battery outer surface side and a small diameter portion on the battery inner surface side;
A terminal cap (5) having:
An energizing contact portion (3a) protruding inward of the battery;
A peripheral portion (3b) located at the periphery of the energization contact portion (3a);
An arch-shaped protrusion (3c) provided in the peripheral portion (3b) in plan view;
A safety valve (3) having
With
The protrusion (3c) of the safety valve is fitted in the counterbore hole (5c) of the terminal cap, and the tip of the protrusion (3c) is crushed so that the protrusion (3c) and the counterbore hole (5c) Rivet fixed,
A sealed battery characterized by that. The sealed battery according to claim 7,
The small-diameter portion of the counterbored hole has a taper portion where the opening area is wide on the battery inner surface side and the opening area becomes narrower toward the outside of the battery.
A sealed battery characterized by that. The sealed battery according to claim 7 or 8,
A plurality of the protrusions and counterbore holes are provided,
A sealed battery characterized by that. The sealed battery according to claim 9, wherein
Each of the protrusions is located on the same circumference;
A sealed battery characterized by that.

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