JP2009080975A - Battery manufacturing method - Google Patents

Abstract

A battery manufacturing method with improved sealing performance is provided.
A shaft portion of an output terminal is extended from the shaft barrel portion having a diameter larger than that of the shaft through hole of the washer, and is larger than the shaft through hole of the washer. If the diameter of the shaft body 16 is A, the length is La, the diameter of the shaft tip 17 is B, and the length is Lb, the relationship between the dimensions is ( The relationship of 1) and (2) is satisfied. A> B (1), π (A / 2) ² La> π (B / 2) ² Lb (2) Is the battery pressed by pressing the shaft tip 17 of the output terminal 8 perpendicularly to the extension direction? By tightening, the outer diameters of the shaft tip portion 17 and the shaft barrel portion 16 are expanded, and the maximum expanded portion of the shaft barrel portion 16 is set to the side wall portion of the through hole 10 of the lid 5 or the shaft through hole 22 of the insulating plate 6. It is manufactured by being positioned on the side wall.
[Selection] Figure 5

Description

  The present invention relates to a battery manufacturing method.

  In recent years, with the development of electronic devices, lithium secondary batteries have been developed as non-aqueous electrolyte secondary batteries that are small, lightweight, have high energy density, and can be repeatedly charged and discharged. Recently, it is suitable for in-vehicle secondary batteries mounted on hybrid cars and electric cars, and secondary batteries for power storage used for power leveling. Development of a nonaqueous electrolyte secondary battery is desired. As such a secondary battery, for example, as described in Patent Document 1, lithium titanium oxide (lithium titanium composite oxide) having a small particle size (average particle size of primary particles is 1 μm or less) as a negative electrode active material. A non-aqueous electrolyte secondary battery that can be rapidly charged and discharged with high power and has excellent cycle performance has been developed.

  On the other hand, a metal can has been put into practical use as an exterior member that houses the positive electrode, the negative electrode, and the like of the non-aqueous electrolyte secondary battery as described above. In a sealed battery using this metal can, the opening of the metal can is sealed with a lid. The cover body has a through hole for fixing the output terminal, and the output terminal is fixed in a state of vertically penetrating the cover body through a plastic gasket. The gasket also serves as an insulator that avoids direct contact between the output terminal and the lid. In this case, the output terminal has a head part exposed on the outer surface of the gasket and a shaft part fitted into the gasket. By caulking with a press equipped with a punch that presses the output terminal perpendicularly to the direction in which the shaft extends, the shaft is expanded, and the cylindrical shaft of the gasket is pressed against the through-hole side wall of the lid. Fix the output terminal and gasket.

  However, according to the above caulking method, the tip of the shaft portion directly hit by the punch at the time of caulking is most expanded, so that the portion from the intersection of the terminal head and the shaft portion to the tip of the shaft portion is expanded in a tapered shape (for example, Patent Document 2). For this reason, when an impact or vibration is applied in parallel to the shaft, the pressure contact between the gasket's cylindrical shaft and the terminal shaft is displaced and loosely adhered, resulting in poor performance or leakage due to reduced airtightness. The problem was easy to occur.

  By the way, Patent Document 3 relates to a sealed battery in which an insulating member having a through hole is interposed in an opening provided in a battery can, and an electrode lead-out pin conductively connected to the power generation element is caulked and fixed in the through hole. Is. In the battery described in Patent Document 3, the electrode lead-out pin is constituted by a collar portion and a cylindrical portion coupled to the collar portion, and the association between the cylindrical portion and the collar portion is brought into contact with the insulator. What has a part larger in diameter than the part is used.

However, if a portion having a large diameter is provided in advance in the electrode lead-out pin as in Patent Document 3, when the electrode lead-out pin is inserted into the through-hole of the insulating member, the through-hole expands and deforms in the radial direction. A gap is easily formed between the electrode lead-out pin and the electrode lead-out pin, and sufficient sealing performance cannot be obtained.
JP-A-2005-123183 JP-A-2005-56648 JP 2001-185100 A

  The present invention provides a method for manufacturing a battery with improved hermeticity.

A battery manufacturing method according to the present invention includes a battery can,
A lid that closes the opening of the battery can and has a through hole;
An insulating plate having a shaft through-hole disposed on one surface of the lid and provided to communicate with the through-hole of the lid;
A washer disposed on the insulating plate and having a shaft through hole provided to communicate with the shaft through hole of the insulating plate;
The flange is disposed on the other surface of the lid and has an opening in the flange so as to communicate with a flange having a recess, a cylindrical shaft extending from the flange, and a hollow in the cylindrical shaft. An insulating gasket provided with a shaft insertion hole;
A method for manufacturing a battery comprising a head and an output terminal having a shaft portion extending from the head,
The shaft portion of the output terminal has a shaft barrel portion having a larger diameter than the shaft through hole of the washer, and a shaft extending from the shaft barrel portion and having a diameter smaller than that of the shaft through hole of the washer. When the diameter of the shaft body portion is A, the length is La, the diameter of the shaft tip portion is B, and the length is Lb, the relationship between the dimensions is as follows (1) and ( 2) Satisfy the relationship of the formula,
A> B (1)
π (A / 2) ² La> π (B / 2) ² Lb (2)
The head of the output terminal is disposed in the recess of the flange portion of the insulating gasket, and the shaft portion of the output terminal is inserted into the shaft insertion hole and the cylindrical shaft portion of the insulating gasket. Extending the shaft tip from the cylindrical shaft,
Inserting the cylindrical shaft portion of the insulating gasket into the through hole of the lid and extending the shaft tip portion from the through hole;
Inserting the shaft tip extending from the through hole of the lid into the shaft through hole of the insulating plate and the shaft through hole of the washer;
By caulking the shaft tip of the output terminal perpendicularly with respect to the extension direction, the outer diameter of the shaft tip and the shaft barrel is expanded, and the maximum extension of the shaft barrel is increased. And a step of positioning on the side wall portion of the through hole of the lid or the side wall portion of the through hole for the shaft of the insulating plate.

  ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of the battery which improved airtightness can be provided.

  The present invention relates to a method for manufacturing a battery including a metal battery can in which a positive electrode, a negative electrode, an electrolytic solution, and the like are housed, and a lid that closes an opening of the battery can. The lid body has a through hole, and a terminal that outputs the positive electrode side or the negative electrode side is caulked and fixed to the through hole of the lid body via a gasket that insulates the output terminal and the battery can. The output terminal has, for example, a T shape composed of a head portion having a flat portion and a shaft portion. The gasket has a cylindrical shaft portion that fits into the shaft portion of the output terminal. A washer is disposed inside the lid via an insulating plate. A positive or negative conductive tab is electrically connected to the washer. The output terminal is caulked and fixed to the lid, the insulating plate, and the washer, so that the lid, the insulating plate, and the washer are integrated.

  The present invention improves the adhesion of the shaft portion of the output terminal and the cylindrical shaft portion of the gasket by improving the structure of the shaft portion of the output terminal, and prevents leakage when an impact such as dropping or vibration is applied. It has been prevented. That is, the shaft portion of the output terminal has a shaft barrel portion having a diameter larger than that of the washer shaft through hole, and a shaft tip portion extending from the shaft barrel portion and having a diameter smaller than that of the washer shaft through hole. In addition, when the diameter of the shaft body portion is A, the length is La, the diameter of the shaft tip portion is B, and the length is Lb, the relationship between the dimensions is the relationship of the following expressions (1) and (2): By satisfying the above, the maximum extension portion formed in the shaft body portion of the output terminal by caulking can be positioned on the side wall portion of the through hole of the lid or the side wall portion of the shaft through hole of the insulating plate. As a result, the cylindrical shaft portion of the gasket and the output terminal shaft portion are not easily misaligned even when the output terminal is subjected to impact or vibration, and problems such as poor performance and liquid leakage due to a decrease in airtightness can be solved.

A> B (1)
π (A / 2) ² La> π (B / 2) ² Lb (2)
A method for manufacturing a sealed battery according to an embodiment of the present invention will be described with reference to the drawings. First, a sealed battery manufactured by the method according to the present embodiment will be described with reference to FIGS. 1 and 2. FIG. 1 is a perspective view schematically showing a sealed battery manufactured by the method according to the present embodiment, and FIG. 2 is a schematic assembly view of the sealed battery shown in FIG.

  As shown in FIGS. 1 and 2, the battery includes a vertically long rectangular box-shaped battery can 1 having an open top surface, an electrode group 2 and an electrolyte solution (not shown) filled in the battery can 1, a battery A sealing member for closing the opening of the can 1 is provided. The battery can 1 is formed by deep drawing. The electrode group 2 includes a sheet-like positive electrode (not shown) in which a positive electrode active material such as lithium cobaltate is thinly formed on a metal foil, and a sheet-like negative electrode in which a negative electrode active material such as graphite is thinly formed on a metal foil. (Not shown) is wound in an oval shape with a separator (not shown) in between. The positive electrode tab 3 electrically connected to the positive electrode of the electrode group 2 extends upward from the upper end surface of the electrode group 2. The negative electrode tab 4 that is electrically connected to the negative electrode of the electrode group 2 extends upward from the upper end surface of the electrode group 2.

  As shown in FIG. 2, the sealing member is disposed on the lid 5 that closes the upper surface opening of the battery can 1, the plastic insulating plate 6 disposed inside the lid 5, and the lower surface of the insulating plate 6. A washer 7, a lid 5, an insulating plate 6, an output terminal 8 that is caulked and fixed to the washer 7, a gasket 9 that is interposed between the output terminal 8 and the lid 5, and the like.

  As shown in FIG. 2, the cover 5 has a through hole 10 formed on the plate surface for attaching the gasket 9, and a receiving seat 11 for the gasket 9 is formed on the opening periphery of the upper surface side of the through hole 10. A dent is formed. Further, the pressure release valve 12 has a role of breaking and releasing the internal pressure when the case internal pressure exceeds a certain pressure. The electrolyte inlet 13 is closed with a sealing plug 14 after the electrolyte is injected. The sealing plug 14 is welded to the lid 5.

  In FIG. 2, the output terminal 8 is formed of a rectangular head portion 15, a columnar shaft body portion 16 extending from the head portion 15, and a columnar shaft tip portion 17 extending from the shaft body portion 16. The Here, when the diameter of the shaft body portion 16 is A, the length is La, the diameter 17 of the shaft tip portion is B, and the length is Lb, the relationship among the dimensions satisfies the following relationship. During caulking, pressure is applied to the shaft tip 17.

A> B (1)
π (A / 2) ² La> π (B / 2) ² Lb (2)
The gasket 9 is a plastic molded product formed of a rectangular flange portion 18 and a round shaft-shaped cylindrical shaft portion 19 extending from the lower surface of the flange portion 18. The hollow in the cylindrical shaft portion 19 penetrates vertically and communicates with a shaft insertion hole 20 opened in the flange portion 18. A shaft body portion 16 of the output terminal 8 is fitted to the cylindrical shaft portion 19. Further, the cylindrical shaft portion 19 is pressed against the side wall portion of the through hole 10 during caulking. The flange portion 18 is formed with a recess 21 in which the head portion 15 of the output terminal 8 is accommodated.

  The insulating plate 6 is a rectangular insulating resin plate opened in the vicinity of the center so that the shaft through hole 22 for mounting the gasket 9 communicates with the through hole 10 of the lid 5. On the other hand, the washer 7 has an annular shape. The shaft through-hole 23 opened in the center of the washer 7 is smaller than the diameter of the shaft body portion 16 of the output terminal 8 and larger than the diameter of the shaft tip portion 17.

  The material of the battery can 1, the lid 5, the washer 7 and the output terminal 8 is changed according to the type of the active material, and is made of, for example, aluminum, aluminum alloy, iron, nickel or the like.

  The positive electrode tab 3 extending from the electrode group 2 is welded to either the lid 5 or the battery can 1, and the negative electrode tab 4 is welded to the washer 7 or the output terminal 8. Thus, the battery can 1 becomes a positive electrode, and the output terminal 8 functions as a negative electrode terminal. The positive electrode tab 3 and the negative electrode tab 4 described above may be welded in reverse. However, the materials of the battery can 1 and the output terminal 8 are limited depending on the types of the positive electrode active material and the negative electrode active material. Further, another output terminal may be installed on either the lid or the battery can to form two locations, and the positive electrode tab 3 and the negative electrode tab 4 may be welded respectively. In this case, the battery can 1 is neutral.

  A method for assembling the sealing member will be described with reference to FIGS. 1 and 2 and FIGS.

(First step)
As shown in FIG. 3, the head portion 15 of the output terminal 8 is housed in the recess 21 of the flange portion 18 of the gasket 9, and the shaft body portion 16 of the output terminal 8 is inserted into the shaft insertion hole 20 and the cylindrical shaft of the gasket 9. The shaft tip portion 17 of the output terminal 8 is protruded from the cylindrical shaft portion 19 by being inserted into the portion 19.

(Second step)
As shown in FIG. 4, the cylindrical shaft portion 19 of the gasket 9 in which the output terminal 8 is inserted is inserted into the through hole 10 of the lid body 5, and the flange portion 18 of the gasket 9 is arranged in the receiving seat 11 of the lid body 5. At the same time, the shaft tip portion 17 of the output terminal 8 protruding from the cylindrical shaft portion 19 of the gasket 9 is extended to the inside of the lid 5.

(Third step)
As shown in FIG. 5, the insulating plate 6 and the washer 7 are sequentially inserted into the shaft tip portion 17 of the output terminal 8 extending inside the lid 5, and the tip of the shaft tip portion 17 is placed inside the washer 7. Make it protrude.

(Fourth process)
As shown in FIG. 6, the head 15 of the output terminal 8 is placed on the caulking jig 24 with the head 15 facing down. Next, caulking is performed by pressing the shaft tip 17 of the output terminal 8 perpendicularly to the extending direction L with a press equipped with a caulking punch 25, and the outer diameters of the shaft tip 17 and the shaft body 16 are expanded. The cylindrical shaft portion 19 of the gasket 9 is brought into pressure contact with the side wall of the through hole 10 of the lid body 5 to fix the output terminal 8 and the gasket 9 and at the same time fix the washer 7.

  The shaft of the output terminal 8 has a two-stage structure with different diameters. Specifically, the diameter of the shaft tip portion 17 is smaller than the shaft through hole 23 of the washer 7, and the shaft barrel portion 16 has a diameter of the shaft. It is larger than the through-hole 23 for use. Further, when the diameter of the shaft body portion 16 is A, the length is La, the diameter of the shaft tip portion 17 is B, and the length is Lb, the relationship of the respective dimensions is the following formulas (1) and (2) Satisfy the relationship.

A> B (1)
π (A / 2) ² La> π (B / 2) ² Lb (2)
With such a configuration, when crushing the shaft tip portion 17 for caulking, the pressure can be concentrated at the center of the shaft barrel portion 16, so that the intermediate point of the shaft barrel portion 16 can be expanded, Insulate the maximum extension part 26 of the shaft body 16 at a position (shown in FIG. 7) where the maximum extension part 26 of the shaft body part 16 faces the side wall part of the through hole 10 of the lid 5 or as shown in FIG. The plate 6 can be disposed at a position facing the side wall portion of the through hole 22 of the plate 6. As a result, the cylindrical shaft portion 19 of the gasket 9 and the shaft portion of the output terminal 8 are not easily misaligned even when the output terminal 8 receives an impact or vibration, and solves problems such as poor performance and liquid leakage due to a decrease in airtightness. can do.

  Hereinafter, the electrode group and the nonaqueous electrolyte will be described.

1) Electrode group What has a flat shape can be used for an electrode group. The flat electrode group is produced, for example, by winding the positive electrode and the negative electrode in a flat spiral shape via a separator, or alternately laminating the positive electrode and the negative electrode with a separator interposed therebetween.

As the positive electrode active material contained in the positive electrode, various oxides such as manganese dioxide, lithium manganese composite oxide (for example, LiMn ₂ O ₄ , LiMnO ₂ ), lithium-containing nickel oxide, lithium-containing cobalt oxide (for example, LiCoO ₂ ), lithium-containing nickel cobalt oxide (for example, LiNi _0.8 Co _0.2 O ₂ ), lithium-containing iron oxide, vanadium oxide containing lithium, chalcogen compounds such as titanium disulfide and molybdenum disulfide Can do. In addition, the kind of positive electrode active material to be used can be made into 1 type or 2 types or more.

  As the positive electrode current collector carrying the positive electrode active material, a conductive substrate having a porous structure or a nonporous conductive substrate can be used. These conductive substrates can be formed from, for example, aluminum, stainless steel, or nickel.

  As the negative electrode active material included in the negative electrode, lithium ions or a material that absorbs and releases lithium can be used. For example, a graphite material or a carbonaceous material (for example, graphite, coke, carbon fiber, spherical carbon, thermal decomposition) Gas phase carbonaceous material, resin fired body, etc.), chalcogen compound (eg, titanium disulfide, molybdenum disulfide, niobium selenide, etc.), light metal (eg, aluminum, aluminum alloy, magnesium alloy, lithium, lithium alloy, etc.), lithium Examples thereof include titanium oxide (for example, spinel type lithium titanate).

  As the negative electrode current collector carrying the negative electrode active material, a conductive substrate having a porous structure or a non-porous conductive substrate can be used. These conductive substrates can be formed from, for example, copper, aluminum, stainless steel, or nickel.

  As the separator, a microporous film, a woven fabric, a non-woven fabric, a laminate of the same material or different materials among these can be used. Examples of the material for forming the separator include polyethylene, polypropylene, ethylene-propylene copolymer, and ethylene-butene copolymer. As a material for forming the separator, one type or two or more types selected from the types described above can be used.

2) Electrolytic solution The electrolytic solution contains a nonaqueous solvent and an electrolyte (for example, lithium salt) dissolved in the nonaqueous solvent. The form of this non-aqueous electrolyte can be liquid (non-aqueous electrolyte), gel or solid.

  Examples of the non-aqueous solvent include ethylene carbonate (EC), propylene carbonate (PC), butylene carbonate (BC), dimethyl carbonate (DMC), diethyl carbonate (DEC), ethyl methyl carbonate (EMC), γ-butyrolactone (γ -BL), sulfolane, acetonitrile, 1,2-dimethoxyethane, 1,3-dimethoxypropane, dimethyl ether, tetrahydrofuran (THF), 2-methyltetrahydrofuran and the like. Nonaqueous solvents may be used alone or in combination of two or more.

Examples of the electrolyte include lithium perchlorate (LiClO ₄ ), lithium hexafluorophosphate (LiPF ₆ ), lithium tetrafluoroborate (LiBF ₄ ), lithium hexafluoroarsenide (LiAsF ₆ ), and trifluoromethanesulfone. Examples thereof include lithium salts such as lithium acid lithium (LiCF ₃ SO ₃ ). The electrolyte may be used alone or in combination of two or more. The amount of electrolyte dissolved in the non-aqueous solvent is desirably 0.2 mol / L to 3 mol / L.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings described above.

Example 1
<Production of electrode group>
First, 89 parts by weight of LiCoO ₂ powder as an active material, 8 parts by weight of graphite powder as a conductive filler, and 3 parts by weight of polyvinylidene fluoride resin as a binder were mixed with 25 parts by weight of N-methylpyrrolidone to prepare a paste. .

  After applying this paste so that an edge part of 50 mm x 70 mm on one side remains as an uncoated part on both sides of an aluminum foil positive electrode current collector having an outer dimension of 50 mm x 590 mm and a thickness of 0.03 mm as a current collector, and after drying And rolled into a positive electrode mixture layer.

  Next, a positive electrode was prepared by welding an aluminum positive electrode tab 3 having a thickness of 0.1 mm and a width of 4 mm to an uncoated portion.

  Next, after the mesophase pitch-based carbon fiber was pulverized, 100 parts by weight of the heat-treated carbon fiber powder was mixed with an aqueous solution containing 2 parts by weight of crosslinked rubber latex particles of carboxymethyl cellulose and styrene-butadiene to prepare a paste.

  This paste was applied on both sides of a copper foil having an outer dimension of 51.5 mm × 610 mm and a thickness of 0.015 mm as a negative electrode current collector so that an edge portion of one side 51.5 mm × 60 mm remained as an uncoated portion, and dried. Then, it rolled and it was set as the negative mix layer.

  Next, a negative electrode was prepared by welding a nickel-made negative electrode tab 4 having a thickness of 0.1 mm and a width of 4 mm to an uncoated portion so that the extending direction of the negative electrode tab 4 was the same as the extending direction of the positive electrode tab 3. .

  Next, after placing a separator of a polyethylene microporous membrane of 53 mm × 720 mm between the positive electrode and the negative electrode, it was wound in a spiral shape with a winding machine so that the outermost periphery was covered with the negative electrode current collector. A cylindrical object was produced.

Subsequently, the cylindrical object was heated and pressed at room temperature under a pressure of 10 to 30 kg / cm ² to form a flat shape, and then the positive and negative electrode tabs 3 and 4 were identical to one side of the flat electrode group. 100 flat electrode groups 2 having a thickness of about 8 mm shown in FIG. 2 were finally produced.

<Preparation of non-aqueous electrolyte>
LiPF ₆ as an electrolyte is dissolved to a concentration of 1 mol / L in a non-aqueous solvent in which ethylene carbonate (EC) and dimethyl carbonate (DMC) are mixed at a volume ratio of 1: 1 to obtain a non-aqueous electrolyte solution. Prepared.

<Attaching the terminal>
A head 15 having a rectangular shape with an outer diameter of 6 mm × 4 mm and a height of 4 mm; a cylindrical shaft body 16 having an outer diameter of 3 mm and a length of 1.5 mm extending from the head 15; An iron output terminal 8 formed of a cylindrical shaft tip portion 17 extending from the portion 16 and having an outer diameter φ2 mm and a length of 2.5 mm and having a surface plated with nickel was prepared. As shown in FIG. 3, the output terminal 8 has a rectangular flange portion 18 having a thickness of 0.5 mm, an outer diameter of 4 mm extending from the lower surface of the flange portion 18, a thickness of 0.5 mm, and a length of 1 mm. It was inserted into a gasket 9 of a plastic molded product formed from a round shaft-shaped cylindrical shaft portion 19, and the shaft tip portion 17 was extended from the cylindrical shaft portion 19.

  Next, an aluminum plate having a thickness of 1 mm, a through hole 10 having a diameter of 4 mm for fixing the output terminal 8 and the gasket 9, and a receiving member having a depth of 0.5 mm for arranging the gasket 9 around the through hole. A lid 5 including a seat 11, a pressure release valve 12 that breaks when the case internal pressure exceeds a certain pressure and releases the internal pressure, and an electrolyte injection port 13 was prepared. As shown in FIG. 4, the gasket 9 in which the output terminal 8 has been inserted is inserted into the through hole 10 of the lid 5, and the shaft tip portion 17 is extended from the through hole 10.

  Next, as shown in FIG. 5, the shaft tip 17 of the output terminal 8 extending inside the lid 5 has a shaft through hole 22 having a thickness of 0.5 mm and a diameter of 4.5 mm. An insulating plate 6 and a washer 7 made of iron with nickel plating on the surface and having a thickness of 0.5 mm and a shaft through hole 23 with a diameter of 2.1 mm were inserted in order.

  Next, as shown in FIG. 6, the head 15 of the output terminal 8 was placed on the caulking jig 24 with the head 15 facing down. Next, caulking is performed by pressing the shaft tip 17 of the output terminal 8 perpendicularly to the extending direction L with a press equipped with a caulking punch 25, and the outer diameters of the shaft tip 17 and the shaft body 16 are expanded. The output terminal 8 and the gasket 9 were fixed by pressing the cylindrical shaft portion 19 of the gasket 9 against the side wall of the through hole 10 of the lid 5, and the washer 7 was fixed at the same time.

<Production of sealed battery>
As the battery can 1, a square can having an opening inside dimension of 10 mm × 70 mm, a height of 80 mm, and a can wall thickness of 0.5 mm formed by drawing an aluminum plate. First, the positive electrode tab 3 extending from the electrode group 2 is welded to the lid 5, and one negative electrode tab 4 is welded to the washer 7, and then the electrode group 2 is inserted into the battery can 1 to open the battery can. The lid 5 was fitted to the part, and the fitting part was integrated by seam welding.

  The battery semi-finished product thus obtained was placed under reduced pressure, a non-aqueous electrolyte was injected from the electrolyte injection port 13, the injection port was closed with the sealing plug 14, and then the sealing plug 14 100 pieces of sealed batteries having a length of 11 mm, a width of 71 mm, a height of 84 mm and a capacity of 1000 mAh were produced by seam welding the periphery and welding to the lid body 5.

  Further, when the longitudinal section of the lid body 5 attached with the output terminal 8 used in the first embodiment was confirmed at the center portion of the output terminal, the maximum extension portion 26 of the shaft body portion 16 of the output terminal 8 is shown in FIG. It was confirmed that the cylinder body 16 was positioned in the middle of the body 16, the maximum extension portion 26 of the shaft body 16 was positioned on the side wall of the through hole 10, and pressed against the cylindrical shaft 19 of the gasket 9.

(Example 2)
100 sealed batteries having a capacity of 1000 mAh were produced in the same manner as in Example 1 except that the lengths of the shaft body 16 and the shaft tip 17 of the output terminal 8 were set to the values shown in Table 1 below.

  Further, when the longitudinal section of the lid 5 attached with the output terminal 8 used in the second embodiment was confirmed in the center portion of the output terminal, the maximum extension portion 26 of the shaft body portion 16 of the output terminal 8 is shown in FIG. Located in the middle of the body portion 16 and the maximum extension portion 26 of the shaft body portion 16 is located on the side wall portion of the shaft through hole 22 of the insulating plate 6 (opposite the terminal head 15 side through the through hole 10). Position).

(Comparative example)
100 sealed batteries having a capacity of 1000 mAh were produced in the same manner as in Example 1 except that the lengths of the shaft body 16 and the shaft tip 17 of the output terminal 8 were set to the values shown in Table 1 below.

  Further, when the longitudinal section of the lid body 5 attached with the output terminal 8 used in this comparative example was confirmed at the center portion of the output terminal, the maximum extension portion 26 of the shaft barrel portion 16 of the output terminal 8 was as shown in FIG. It was confirmed that the maximum extension part 26 of the shaft body part 16 is located on the terminal head part 15 side with respect to the through hole 10 and is located in the middle of the part 16.

(Conventional example)
100 sealed batteries with a capacity of 1000 mAh were produced in the same manner as in Example 1 except that the shaft tip portion 17 of the output terminal 8 was eliminated and the length of the shaft body portion 16 was changed to the value shown in Table 1 below.

  Further, when the longitudinal section of the lid body 5 attached with the output terminal 8 used in this conventional example was confirmed at the center portion of the output terminal, the maximum extension portion 26 of the shaft barrel portion 16 of the output terminal 8 was found to be the shaft barrel as shown in FIG. It was confirmed that it was at the tip of the portion 16 and was in a position facing the terminal head 15 side through the through hole 10.

100 of each of these batteries were charged, 50 batteries were dropped 10 times from the bottom of the battery can 1 with the head 15 of the output terminal 8 facing upward on the concrete from a height of 50 cm, and the output terminal When the head 15 of 8 is dropped 10 times and when 50 batteries are each subjected to vibration in the three directions X, Y, Z according to the random vibration in JIS Z 2032 Appendix A Table 1 Table 1 shows the number of batteries that leaked from the fixed portion of the output terminal 8 in the lid 5.

From the results shown in Table 1, the shaft body portion having a diameter larger than the shaft through hole of the washer and the shaft tip portion having a diameter smaller than the shaft through hole of the washer and the shaft body portion and the shaft tip portion are described above. An embodiment in which the output terminal satisfying the relationship of the expressions (1) and (2) is used, and the maximum extension part of the shaft body part is located on the side wall part of the through hole of the lid or the side wall part of the shaft through hole of the insulating plate. According to Nos. 1 and 2, it can be seen that there is no number of leaks during the drop test and vibration test. In Example 1, π (A / 2) ² La in the formula (2) was 3.375π and π (B / 2) ² Lb was 2.5π. In Example 2, π (A / 2) ² La in formula (2) was 4.275π and π (B / 2) ² Lb was 2.1π.

On the other hand, the shaft tip portion and the shaft body portion do not satisfy the relationship of the above formula (2) (π (A / 2) ² La is 1.8π, and π (B / 2) ² Lb is 3.2π). ) In the comparative example using the output terminal, since the maximum extension part of the shaft body part was located on the output terminal head side with respect to the through hole of the lid body, the amount of leakage during the drop test and the vibration test increased. When the maximum extension exists on the terminal head side of the cover through-hole, the portion of the cylindrical shaft of the gasket that is in pressure contact with the terminal shaft and the through-hole side wall of the cover is extremely reduced. This is because the lid and the output terminal are not sufficiently fixed. On the other hand, in the conventional example in which the shaft tip portion is not provided, the tip of the shaft barrel portion is most expanded, and the portion from the intersection of the output terminal head and the shaft barrel portion to the tip of the shaft barrel portion is expanded in a tapered shape. In this case, since the maximum extension part of the shaft body part does not hang on the side wall part of the through hole of the lid, the terminal is easily displaced from the outside of the battery when receiving impact or vibration, as shown in the results of Table 1. There were many leaks.

  In the above-described embodiments, the battery using the non-aqueous electrolyte is described as an example, but the present invention is naturally applicable to a battery using a solid electrolyte, a polymer electrolyte, or an aqueous electrolyte instead of the non-aqueous electrolyte. . Furthermore, the positive and negative electrode active materials are not limited to this, and other active materials can be used.

  Note that the present invention is not limited to the above-described embodiment as it is, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. In addition, various inventions can be formed by appropriately combining a plurality of components disclosed in the embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, constituent elements over different embodiments may be appropriately combined.

1 is a perspective view of a sealed battery manufactured by a method according to an embodiment of the present invention. FIG. 2 is a schematic assembly diagram of the sealed battery shown in FIG. 1. Sectional drawing which shows the assembly process of the sealing member of the sealed battery of FIG. Sectional drawing which shows the assembly process of the sealing member of the sealed battery of FIG. Sectional drawing which shows the assembly process of the sealing member of the sealed battery of FIG. Sectional drawing which shows the assembly process of the sealing member of the sealed battery of FIG. FIG. 3 is an enlarged cross-sectional view of a main part in the sealed battery of Example 1. FIG. 4 is an enlarged cross-sectional view of a main part in the sealed battery of Example 2. The principal part expanded sectional view in the sealed battery of a comparative example. The principal part expanded sectional view in the sealed battery of a prior art example.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Battery can, 2 ... Electrode group, 3 ... Positive electrode tab, 4 ... Negative electrode tab, 5 ... Cover body, 6 ... Insulating plate, 7 ... Washer, 8 ... Output terminal, 9 ... Gasket, 10 ... Through-hole, 11 ... Receiving seat, 12 ... Pressure release valve, 13 ... Electrolyte injection port, 14 ... Seal plug, 15 ... Head, 16 ... Shaft body, 17 ... Shaft tip, 18 ... Flange, 19 ... Cylindrical shaft 20 ... Shaft insertion hole, 21 ... Recess, 22, 23 ... Shaft through-hole, 24 ... Caulking jig 24, 25 ... Caulking punch, 26 ... Maximum expansion part.

Claims (1)

A battery can,
A lid that closes the opening of the battery can and has a through hole;
An insulating plate having a shaft through-hole disposed on one surface of the lid and provided to communicate with the through-hole of the lid;
A washer disposed on the insulating plate and having a shaft through hole provided to communicate with the shaft through hole of the insulating plate;
The flange is disposed on the other surface of the lid and has an opening in the flange so as to communicate with a flange having a recess, a cylindrical shaft extending from the flange, and a hollow in the cylindrical shaft. An insulating gasket provided with a shaft insertion hole;
A method for manufacturing a battery comprising a head and an output terminal having a shaft portion extending from the head,
The shaft portion of the output terminal has a shaft barrel portion having a larger diameter than the shaft through hole of the washer, and a shaft extending from the shaft barrel portion and having a diameter smaller than that of the shaft through hole of the washer. When the diameter of the shaft body portion is A, the length is La, the diameter of the shaft tip portion is B, and the length is Lb, the relationship between the dimensions is as follows (1) and ( 2) Satisfy the relationship of the formula,
A> B (1)
π (A / 2) ² La> π (B / 2) ² Lb (2)
The head of the output terminal is disposed in the recess of the flange portion of the insulating gasket, and the shaft portion of the output terminal is inserted into the shaft insertion hole and the cylindrical shaft portion of the insulating gasket. Extending the shaft tip from the cylindrical shaft,
Inserting the cylindrical shaft portion of the insulating gasket into the through hole of the lid and extending the shaft tip portion from the through hole;
Inserting the shaft tip extending from the through hole of the lid into the shaft through hole of the insulating plate and the shaft through hole of the washer;
By caulking the shaft tip of the output terminal perpendicularly with respect to the extension direction, the outer diameter of the shaft tip and the shaft barrel is expanded, and the maximum extension of the shaft barrel is increased. And a step of positioning on the side wall portion of the through hole of the lid body or the side wall portion of the through hole for shaft of the insulating plate.

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