JP2009087729A - Sealed battery - Google Patents

Abstract

Provided is a sealed battery that is excellent in reliability and does not leak even when a heat cycle is applied.
A through-hole of a plate-shaped sealing lid is inserted through a ring-shaped insulating sealing member 5 into a head 22 having an outer diameter larger than the inner diameter of the through-hole and an outer diameter smaller than the inner diameter of the through-hole. A headed rivet-shaped electrode terminal having a shaft portion 23 is inserted into the sealing lid, the outer diameter of the sealing lid is increased by caulking the electrode terminal, and the insulating sealing member is compressed and sandwiched. In a sealed battery comprising a battery outer case having a stopped outer structure and a positive electrode and a negative electrode housed in the battery outer case, the through hole of the sealing lid is a head from the side facing the end of the electrode terminal. And an inner diameter D1 defining a first narrow portion on the side facing the end of the electrode terminal of the insulating sealing member and a head of the electrode terminal of the insulating sealing member. Inner diameter that defines the second narrow part on the side facing the part 2 and is in a relationship of D1> D2.
[Selection] Figure 1

Description

  The present invention relates to a sealed battery with improved sealing performance.

  A sealed battery typified by a lithium ion battery using a non-aqueous electrolyte is characterized by high energy density and is widely used in small portable devices typified by mobile phones and the like. In addition to the cylindrical battery, some sealed batteries use a rectangular outer case for the purpose of improving volumetric efficiency in accordance with the shape of a small portable device.

  In recent years, not only for portable devices that have been used in the past, but also due to the growing interest in environmental issues, improvement of energy density, input / output characteristics, and cycle characteristics aiming at application to electric cars, hybrid cars, power storage, etc. The demand for is increasing.

  As a battery suitable for such a demand, as described in Patent Document 1, a negative electrode current collector made of an aluminum or aluminum alloy foil having an average crystal particle diameter of 50 μm or less and a particle size distribution having a primary particle diameter of 1 μm or less A non-aqueous electrolyte secondary battery including a negative electrode having a negative electrode active material having a negative electrode active material has been proposed. According to this, since the proposed negative electrode active material has a potential of 0.4 V or more during lithium occlusion and does not form a lithium aluminum alloy, aluminum or an aluminum alloy can be used for the current collector. It is said that. Furthermore, since the strength of the current collector is improved by setting the average crystal grain size of the current collector to 50 μm or less, a powder having a particle size distribution with a primary particle diameter of 1 μm or less may be used as the negative electrode active material. It is also described that the electrode density can be improved and the energy density and input / output characteristics can be improved.

  In addition, in these applications, since the service life of the device becomes long, the long-term reliability related to the sealing property of the battery such as 10 to 15 years with respect to the use period of about 2 to 3 years for the small portable device so far. There is a request. Furthermore, in these large devices, it is necessary to improve the storage capacity per battery as well as to improve the battery input / output characteristics, etc., and there is also a demand for reducing the weight of the battery in applications such as electric vehicles. It is necessary to reduce the weight of battery exterior members other than battery power generation elements.

  As a battery using a rectangular battery outer case for a conventional small portable device, for example, Patent Document 2 discloses that one end of a shaft portion is inserted into a through hole of a lid disposed in an opening portion of the battery case via an insulating packing. Insert a terminal (output terminal) having a head into the top, compress the terminal from above and below, and crimp the end to the opposite end of the head and the outer diameter of the shaft, A sealed battery sealed by compression and sandwiching is disclosed.

That is, by combining the negative electrode described in Patent Document 1 with a positive electrode active material such as lithium manganese composite oxide or lithium cobalt composite oxide, the energy density and input / output characteristics can be improved, and the negative electrode current collecting member and the positive electrode current collector can be improved. Since aluminum or an aluminum alloy can be used for both electrical members, a relatively inexpensive and lightweight battery can be formed by combining with the conventional battery case exterior structure described in Patent Document 2 described above.
JP-A-2005-123183 JP 2003-272574 A

  However, even if the battery case has the above configuration, the following problems occur when the application (use environment) is different.

  As mentioned above, when a battery is enlarged to expand the storage capacity of the battery due to the installation of the sealed battery in a large device such as an electric vehicle, a hybrid vehicle, or a power storage device, the strength of the battery is secured. Therefore, it is necessary to increase the wall thickness of the metal can and the plate-shaped sealing lid constituting the rectangular battery outer case. For example, the thickness of a sealing lid for a conventional small portable device is 0.25 mm or less, whereas the thickness of a sealing lid for a large device is 0.3 mm or more. Thus, the total weight of a battery increases by thickening a member.

  In view of this, all of the metal can, the plate-shaped sealing lid, and the headed rivet-shaped electrode terminal are made of aluminum or an aluminum alloy, thereby reducing the weight of the entire battery outer case. However, if these members are made of aluminum or an aluminum alloy, the outer diameter of the shaft portion near the caulking portion of the rivet-shaped electrode terminal first expands, resulting in significant variation in the compressibility of the ring-shaped insulating sealing member, resulting in leakage. May cause liquid.

  That is, as shown in FIG. 4, in the conventional sealed battery 100, the ring-shaped insulating sealing member 5 is fitted into the through hole 42 of the sealing lid 4, and the insulating plate 6 is inserted into the small diameter portion of the insulating sealing member 5 from the inside. A headed rivet-shaped electrode terminal fitted around and having a head portion 22 having an outer diameter larger than the inner diameter D1 (= D2) of the through hole and a shaft portion 23 having an outer diameter smaller than the inner diameter D1 (= D2) of the through hole. 20 is inserted into the opening of the insulating sealing member 5 from the outside, and the washer 7 is further inserted from the inside into the shaft portion 23 of the electrode terminal, and the electrode terminal 20 is compressed by caulking from above and below. During this caulking, the end portion 28 of the shaft portion 23 is crushed and flattened, and the outer diameter of the shaft portion 23 is enlarged. However, aluminum or an aluminum alloy has a yield stress as compared with other metal materials such as nickel and iron. Since it is low, the shaft portion (inner portion) in the vicinity of the crimping end portion 28 of the rivet-shaped electrode terminal is first buckled and bulged, and the shaft portion (outer portion) in the vicinity of the head portion 22 of the rivet-shaped electrode terminal is plastic. Since it is difficult to deform, the compressibility of the insulating sealing member 5 varies greatly between the first narrow portion 16 near the caulking end portion and the second narrow portion 17 near the rivet head portion. Due to the variation in the compression ratio, in particular, when a heat cycle (for example, −20 ° C. to 70 ° C.) reproducing a normal use environment is applied, the pressing force by the insulating sealing member 5 is reduced due to the expansion and contraction of the member, There is a risk of leakage due to a decrease in sealing performance.

  The present invention has been made in order to solve the above-described problems, and even when a heat cycle is applied over a long period of time, the sealing performance is maintained, and there is no occurrence of liquid leakage and excellent long-term reliability. An object is to provide a sealed battery.

  The sealed battery according to the present invention includes a metal can, a plate-shaped sealing lid through-hole, a ring-shaped insulating sealing member, and a head having an outer diameter larger than the inner diameter of the through-hole and the through-hole. A headed rivet-shaped electrode terminal having an outer diameter smaller than the inner diameter of the sealing lid is inserted from one side of the sealing lid, and the electrode terminal is compressed from above and below and crimped to the other side of the sealing lid. A battery outer case having an outer structure sealed by enlarging the outer diameter of the end portion and the shaft portion of the electrode terminal and compressing and sandwiching the insulating sealing member, and a positive electrode and a negative electrode housed in the battery outer case In the sealed battery having the electrode group, the through hole of the sealing lid is gradually reduced in diameter from the side facing the end of the electrode terminal toward the side facing the head, and the insulating sealing member A first narrow portion on the side facing the end of the electrode terminal is defined. And the inner diameter D2 defining a second narrow portion on the side facing the head of the electrode terminal of the insulating sealing member and an inner diameter D1 which is characterized in that a relationship of D1> D2.

  In the sealed battery of the present invention, since the inner diameter of the through hole of the sealing lid has a relationship of D1> D2, when the rivet electrode terminal is caulked at the time of sealing, the shaft portion of the expanded electrode terminal and the inner diameter D1 The thickness of the first narrow portion on the side facing the rivet end portion of the insulating sealing member defined between the through hole peripheral wall and the shaft portion (substantially initial diameter) of the electrode terminal and the through hole peripheral wall of the inner diameter D2 The thickness of the second narrow portion on the side facing the rivet head of the insulating sealing member defined between them is just the same level with a good balance (see FIG. 1), and the compressibility of the insulating sealing member is made uniform as a whole. Is done. As a result, the creep phenomenon that occurs in the insulating sealing member when subjected to a heat cycle is reduced or suppressed, and a highly reliable sealed battery that does not leak over a long period of time is obtained.

  ADVANTAGE OF THE INVENTION According to this invention, even if it is a case where it receives a heat cycle over a long period of time, the sealing type battery excellent in long-term reliability which maintains desired sealing property and does not generate | occur | produce a liquid leakage is provided. The sealed battery of the present invention can be used safely without causing liquid leakage for a long period of time, and is relatively inexpensive and lightweight. Therefore, the sealed battery particularly mounted on a hybrid vehicle or an electric vehicle or power This is suitable as a secondary battery for power storage used for leveling.

  As a result of intensive studies on the sealing performance of the sealing lid caulking portion of the sealed battery, the inventors have previously determined the shape of the through hole of the sealing lid in advance and the inner diameter D1 of the through hole in the vicinity of the caulking portion of the rivet electrode terminal. And the inner diameter D2 of the through hole in the vicinity of the head portion of the rivet-shaped electrode terminal satisfying D1> D2, so that even when both the sealing lid and the rivet-shaped electrode terminal are made of aluminum or an aluminum alloy, good sealing is achieved. It was found that the battery performance can be maintained over a long period of time, and the battery outer case can be reduced in weight. The present invention has been made based on such findings.

  In the present invention, it is preferable that the inner diameter D2 is 3 mm or more and the ratio D1 / D2 is 1.05 or more. When the sealing lid caulking seal portion is made of aluminum or an aluminum alloy, the diameter of the shaft portion of the rivet-shaped electrode terminal is required to be larger than at least 3 mm in order to compensate the strength for preventing breakage. For this reason, the inner diameter D2 of the through hole needs to be 3 mm or more in the sealing lid. Further, in the sealing lid caulking seal portion where the ratio D1 / D2 is less than 1.05, the leakage occurrence rate is high (Comparative Examples 1 and 2 in Table 1), whereas the ratio D1 / D2 is 1.05 or more. No leakage occurs at the sealing lid caulking seal part (Examples 1 to 4 in Table 1). This is because in the latter case, the variation in the compressibility of the insulating sealing member is reduced.

  In the present invention, the height (axial length) H of the through hole of the sealing lid can be set to 0.3 mm or more. For power supplies for large equipment, it is necessary to make the sealing lid thicker for strength compensation, and it is recommended that the thickness of the sealing lid made of aluminum or aluminum alloy be 0.3 mm or more. For this reason, it is desirable that the height H of the through hole be 0.3 mm or more. By the way, when the height H of the through hole is increased, the compression rate of the insulating sealing member is more likely to vary. However, in the sealing lid of the present invention, the relationship between the inner diameters D1 and D2 of the through hole is D1> D2, and the rivet end Since the compressibility of the insulating sealing member is made uniform between the first narrow portion on the side facing the portion and the second narrow portion on the side facing the rivet head, the heat seal was subjected to a heat cycle over a long period of time. Even in this case, no leakage occurs.

  In the present invention, the negative electrode housed in the battery case is a current collector made of an aluminum or aluminum alloy foil as a negative electrode active material in which the lithium ion occlusion / release potential is more noble than 0.4 V with respect to the potential of metallic lithium. It is desirable to apply to the body. This is because the chemical reaction between the negative electrode active material and aluminum or aluminum alloy can be suppressed.

  Hereinafter, a prismatic lithium ion battery will be described with reference to FIGS. 1 and 2 as a sealed battery according to an embodiment of the present invention.

  As shown in FIGS. 2A and 2B, the sealed battery 1A of the present embodiment includes a metal can 10 whose upper surface is opened in a substantially rectangular shape, an electrode group 11 filled in the metal can 10, and An electrolytic solution, a sealing lid 4A for closing the opening of the metal can 10, a positive electrode tab 9a and a negative electrode tab 9b, a sealing plug 13 for closing the electrolytic solution injection port 12, and a rivet-shaped electrode terminal 20 are provided. The electrolyte injection port 12 is injected with the electrolyte into the metal can 10 which is a battery outer case, sealed with a sealing plug 13, and laser welded to the sealing lid 4A.

  The metal can 10 is manufactured by deep drawing an aluminum plate or an aluminum alloy plate, and also serves as an output terminal on the positive electrode side.

  The electrode group 11 includes a sheet-like positive electrode in which a positive electrode active material is applied to a current collector made of aluminum or an aluminum alloy, and a sheet-like negative electrode in which a negative electrode active material is applied to a current collector made of aluminum or an aluminum alloy. After being wound in a spiral shape through an insulating separator, the cross section is crushed into an oval shape in accordance with the cross sectional shape of the metal can 10. The positive and negative electrode conductive tabs 9a and 9b are led out from the positive electrode sheet and the negative electrode sheet of the electrode group 11, and are electrically connected to the positive electrode terminal 19 and the rivet electrode terminal 20, respectively. In this example, the member 19 is a positive terminal and the member 20 is a negative terminal. However, the wiring connection is reversed, the member 19 is a negative terminal, and the member 20 is a positive terminal. Even in the case, the same effect can be obtained.

  Here, as the positive electrode active material, an oxide, sulfide, polymer, or the like that can occlude and release lithium ions can be used. Preferred examples of the positive electrode active material include lithium manganese composite oxide, lithium nickel composite oxide, lithium cobalt composite oxide, and lithium iron phosphate that can provide a high positive electrode potential.

  As the negative electrode active material, metal oxides, metal sulfides, metal nitrides, alloys, and the like that can occlude and release lithium ions can be used. As a preferable negative electrode active material, a material in which the occlusion / release potential of lithium ions is nobler than 0.4 V with respect to the potential of metallic lithium can be given. Since this can suppress the alloy reaction between aluminum or an aluminum alloy and lithium, aluminum or an aluminum alloy can be used for the negative electrode current collector and the negative electrode related constituent member. For example, examples of the negative electrode active material include titanium oxide, lithium titanium oxide, tungsten oxide, amorphous tin oxide, tin silicon oxide, and silicon oxide. Among these, lithium titanium composite oxide is preferable.

  The sealing member used for the sealed battery 1 </ b> A includes a sealing lid 4 </ b> A, a headed rivet-shaped electrode terminal 20, a ring-shaped insulating sealing member 5, an insulating plate 6, and a washer 7. The sealing lid 4A is formed by press-molding an aluminum plate or an aluminum alloy plate having a thickness of 0.3 mm. The sealing lid 4A is entirely welded to the periphery surrounding the rectangular opening of the metal can 10 to close the upper surface opening of the metal can 10. Yes.

  Two openings are formed in the sealing lid 4A. The electrolyte solution injection port 12 is opened substantially at the center of the sealing lid 4 </ b> A, and after the electrolyte solution is injected into the electrode group 11 in the metal can 10, the electrolyte solution injection port 12 is closed by the sealing plug 13. The sealing plug 13 is laser welded all around the sealing lid 4A. The negative electrode terminal extraction opening 42 </ b> A is a through hole for connecting the end of the negative electrode tab 9 b to the negative electrode terminal (headed rivet-shaped electrode terminal) 20. This through hole 42A is gradually reduced in diameter from the inside to the outside of the sealing lid 4A. The inner peripheral wall of the inner diameter D1 of the through hole 42A defines the first narrow portion 16A of the ring-shaped insulating sealing member 5. The outer peripheral wall of the inner diameter D2 of the through hole 42A defines the second narrow portion 17A of the insulating sealing member 5. As shown in FIG. 1, these inner diameters D1 and D2 have a relationship of D1> D2.

  The headed rivet-shaped electrode terminal 20 has a head portion 22, a shaft portion 23, and a caulking end portion 28. The outer diameter of the head 22 is larger than the inner diameter of the through hole 42A of the sealing lid 4A. The outer diameter of the shaft portion 23 is sufficiently smaller than the inner diameter of the through hole 42 </ b> A and slightly smaller than the ring opening diameter of the insulating sealing member 5. A part of the shaft portion 23 (on the side of the caulking end portion 28) bulges during caulking, and the first narrow portion 16A is formed between the inner peripheral wall of the through hole 42A having the inner diameter D1. A second narrow portion 17A is formed between the other portion of the shaft portion 23 (on the head portion 22 side) and the outer peripheral wall of the through hole 42A having the inner diameter D2. The caulking end portion 28 is flattened during caulking so that the rivet electrode terminal 20 does not fall out of the sealing lid 4A.

  The ring-shaped insulating sealing member 5 includes a flange portion 14 and a pipe-shaped boss portion 15 into which a shaft portion 23 of a headed rivet-shaped electrode terminal is inserted on the lower surface of the flange portion 14. Here, the material of the ring-shaped insulating sealing member 5 and the insulating plate 6 is polypropylene, polyphenylene sulfide, tetrafluoroethylene-perfluoroalkoxyethylene copolymer (PFA), tetrafluoroethylene-hexafluoropropylene copolymer (FEP). A synthetic resin having thermoplasticity and insulating properties such as The sealing lid 4A, the rivet electrode terminal 20, the washer 7 and the sealing plug 13 are made of aluminum or an aluminum alloy.

  The sealing part is assembled by the following procedure.

  The pipe-shaped boss portion 15 of the ring-shaped insulating sealing member 5 is inserted into the through hole 42A of the sealing lid 4A, and the headed rivet-shaped electrode terminal 20 is further inserted into the pipe-shaped boss portion 15. Thereafter, as shown in FIG. 1, the washer 7 is inserted into the shaft portion 23 via the insulating plate 6. In this state, the headed rivet-like electrode terminal 20 is compressed from above and below by a caulking machine, and the caulking end portion 28 of the electrode terminal is crushed. During this caulking, the diameter of the shaft portion 23 is increased, and the ring-shaped insulating sealing member 5 is compressed and sandwiched between the inner wall of the through hole 42A of the sealing lid 4A and the shaft portion 23, thereby sealing. The compression rate at this time is preferably in the range of 20 to 80%. If the compression rate is less than 20%, the ring-shaped insulating sealing member 5 and the inner wall of the through-hole 42A of the sealing lid 4A or the ring-shaped insulating sealing member 5 and the shaft portion 23 of the headed rivet-shaped electrode terminal 20 are not sufficiently compressed. It is lowered and good sealing performance cannot be obtained. If the compression ratio exceeds 80%, excessive compression causes the pipe-shaped boss 15 of the ring-shaped insulating sealing member 5 to crack and break, and further follows the expansion / contraction displacement / deformation caused by the heat cycle. The desired sealing performance cannot be maintained. Here, the “compression ratio” is a value given by the compression ratio PR = T2 / T1, where T1 is the thickness of the pipe-shaped boss portion 15 before caulking, and T2 is the thickness of the boss portion 15 after caulking. It is.

  In the description of this embodiment, the head of the headed rivet-shaped electrode terminal is the outside of the battery outer case, and the caulking end is the inner side of the case. The head may be the inside of the battery outer case, and the caulking end may be the outside of the case. In that case, the same effect can be obtained by setting the inner diameter D1 of the plate-shaped sealing lid to the crimping end side of the headed rivet-shaped electrode terminal and the inner diameter D2 to the head side of the terminal.

  Hereinafter, examples of the present invention will be described with reference to FIGS. 1 to 4 and Table 1 in comparison with comparative examples. It should be noted that the present invention is not limited to the following examples as long as the gist of the present invention is not exceeded.

Example 1
In the through hole 42A of the sealing lid 4A, the height H is 0.5 mm, the inner diameter D1 is 4 mm, the outer diameter D2 is 4.4 mm, and the outer diameter of the shaft portion 23 of the headed rivet-shaped electrode terminal 20 1 mm, the thickness of the pipe-shaped boss portion 15 of the ring-shaped insulating member 5 is 0.5 mm on one side, and the shaft portion 23 of the headed rivet-shaped electrode terminal 20 is caulked to assemble the sealing structure shown in FIG. A nonaqueous electrolyte secondary battery 1A having a width of 70 mm, a height of 100 mm, and a thickness of 15 mm was produced. In Example 1, the compression ratio of the pipe-shaped boss portion 15 (the first narrow portion 16A and the second narrow portion 17A) was set to 50%.

(Example 2)
In Example 2, the non-aqueous electrolyte secondary battery 1A shown in FIG. 1 was manufactured in the same manner as in Example 1 except that the outer diameter D2 of the through hole 42A was changed to 4.2 mm. . Also in Example 2, the compression rate of the pipe-shaped boss 15 (the first narrow portion 16A and the second narrow portion 17A) was set to 50%.

(Example 3)
In Example 3, the non-aqueous electrolyte secondary battery shown in FIG. 1 is the same as in Example 1 except that the caulking dimensions are changed and the compression ratio of the pipe-shaped boss portion 15 is 30%. 1A was produced.

Example 4
In Example 4, the non-aqueous electrolyte secondary battery shown in FIG. 1 is the same as that of Example 1 except that the caulking dimensions are changed and the compression ratio of the pipe-shaped boss portion 15 is set to 70%. 1A was created.

(Comparative Example 1)
In Comparative Example 1, the other configuration is the same as that of Example 1 except that the inner diameter D1 of the through hole 42 is 4.0 mm and the outer diameter D2 is 4.0 mm. A nonaqueous electrolyte secondary battery 100 was produced.

(Comparative Example 2)
In Comparative Example 2, the other configuration is the same as that in Example 1 except that the inner diameter D1 of the through hole 42B is 4.0 mm and the outer diameter D2 is 3.6 mm. A nonaqueous electrolyte secondary battery 1B was prepared.

  Heat cycle tests were performed on the nonaqueous electrolyte secondary battery samples of Examples 1 to 4 and Comparative Examples 1 and 2, respectively. The heat cycle test method is held at a low temperature of −30 ° C. for 2 hours and then at a high temperature of + 80 ° C. for 2 hours. This was defined as one cycle, and after 100 cycles, the leakage of the electrolyte solution in each sample was examined. There are 100 test cells each. Table 1 shows the results.

As is clear from Table 1, in Comparative Examples 1 and 2, the compression ratio varies, and the maximum compression portion is 50%, but the other portions have a low compression ratio, and expansion and contraction due to the temperature cycle. It is probable that liquid leakage occurred without following the displacement and deformation caused by

1 is a cross-sectional view of a main part showing a sealed battery according to an embodiment of the present invention. (A) is a longitudinal cross-sectional view of a sealed battery, (b) is a plan view of the sealed battery. Sectional drawing which shows the principal part which shows the battery of a comparative example. The principal part sectional drawing which shows the conventional battery.

Explanation of symbols

1A, 1B, 100 ... sealed battery,
4 ... sealing lid, 5 ... insulating sealing member, 6 ... insulating plate, 7 ... washer,
9a ... positive electrode tab, 9b ... negative electrode tab,
DESCRIPTION OF SYMBOLS 10 ... Metal can, 11 ... Electrode group, 12 ... Electrolyte injection port, 13 ... Seal plug,
14 ... flange part, 15 ... boss part,
16, 16A, 16B ... 1st narrow part,
17, 17A, 17B ... the second narrow part,
20 ... Rivet electrode terminals,
22 ... head, 23 ... shaft, 28 ... caulking end,
42, 42A, 42B ... through hole (opening for negative electrode terminal extraction).

Claims (6)

A metal can and a plate-shaped sealing lid through a ring-shaped insulating sealing member through a ring-shaped insulating sealing member, a head having an outer diameter larger than the inner diameter of the through-hole and an axis having an outer diameter smaller than the inner diameter of the through-hole. A headed rivet-shaped electrode terminal having a portion is inserted from one side of the sealing lid, and the electrode terminal is compressed and caulked from above and below to crimp the end and shaft of the electrode terminal on the other side of the sealing lid. A battery case having an outer structure in which the outer diameter of the portion is enlarged and the insulating sealing member is compressed and sandwiched and sealed, and an electrode group including a positive electrode and a negative electrode housed in the battery outer case In
The through hole of the sealing lid is gradually reduced in diameter from the side facing the end of the electrode terminal toward the side facing the head, and on the side facing the end of the electrode terminal of the insulating sealing member The inner diameter D1 that defines the first narrow portion and the inner diameter D2 that defines the second narrow portion on the side of the insulating sealing member that faces the head of the electrode terminal have a relationship of D1> D2. Sealed battery. 2. The sealed battery according to claim 1, wherein the sealing lid and the headed rivet-shaped electrode terminal are made of aluminum or an aluminum alloy. 3. The sealed battery according to claim 1, wherein the inner diameter D2 is 3 mm or more and the ratio D1 / D2 is 1.05 or more. The sealed battery according to any one of claims 1 to 3, wherein a height of the through hole of the sealing lid is 0.3 mm or more. The sealed battery according to any one of claims 1 to 4, wherein the sealed battery is a nonaqueous electrolyte secondary battery. The negative electrode housed in the battery case is coated on a current collector made of aluminum or aluminum alloy with a negative electrode active material in which the lithium ion occlusion / release potential is more noble than 0.4 V with respect to the potential of metallic lithium. The sealed battery according to claim 1, wherein the sealed battery is worn.

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