Nonaqueous electrolyte secondary battery and method for manufacturing the same

Abstract

A non-aqueous electrolyte secondary battery in which an opening of a battery case is sealed by a sealing plate, the battery comprising a blind rivet which is inserted into an opening hole formed in the sealing plate with a gas permeable membrane therebetween and which is fixed to the sealing plate, wherein: the gas permeable membrane includes a cylindrical part and a flange; the blind rivet comprises a sleeve body which includes a sleeve and a flange, and a mandrel which includes a shaft and a head inserted into a hollow part of the sleeve; in the blind rivet, the sleeve is crimped and fixed to the sealing plate in a state where the sleeve and the head are covered with the cylindrical part; and a space contiguous to the outside of the battery case is formed between the gas permeable membrane and the blind rivet.

Description

[Technical field]

[0001] The present disclosure relates to a nonaqueous electrolyte battery having an internal pressure adjusting mechanism and a method for manufacturing a nonaqueous electrolyte secondary battery. [Background technology]

[0002] Since non-aqueous electrolyte secondary batteries such as lithium ion secondary batteries contain an organic solvent as an electrolyte, gas is generated due to decomposition of the electrolyte during charging and discharging, storage at high temperatures, etc. Therefore, if the battery is used for a long period of time, the pressure inside the battery increases, and the battery case may expand.

[0003] In order to solve such problems, a secondary battery has been proposed that is provided with a mechanism for regulating the pressure within the battery by discharging gas generated within the battery to the outside.

[0004] As such a pressure adjustment mechanism, Patent Document 1 discloses a structure in which a through hole is provided in a lid 201 of a battery case 200, and a holder 202 holding a gas permeable sheet 204 is detachably attached to the through hole with a screw or the like, as shown in Fig. 11. Gas communication holes 203 are formed in the holder 202, and gas generated within the battery permeates the gas permeable sheet 204 and passes through the gas communication holes 203 to be discharged to the outside. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2015-167907 A Summary of the Invention

[0006] There is a demand for higher output from batteries, especially for in-vehicle applications. For example, in the case of lithium-ion secondary batteries, the means for increasing output include increasing the area of ​​the plate and increasing the amount of Ni contained in the positive electrode active material. Increasing the area of ​​the plate reduces the remaining space in the battery case. In addition, an increase in the amount of Ni leads to a decrease in cycle characteristics, so adding an additive to suppress this causes an increase in the amount of gas. As a result, the rate at which the pressure rises inside the battery increases, so it is necessary to increase the rate at which the gas generated inside the battery is discharged accordingly.

[0007] In the pressure adjustment mechanism disclosed in Patent Document 1, the gas discharge rate is determined by the gas permeability of the gas permeable sheet. Therefore, in order to increase the gas discharge rate, it is necessary to increase the area of ​​the gas permeable sheet or to make it thinner.

[0008] However, since the gas permeable sheet 204 disclosed in Patent Document 1 is attached to the open end of the gas communication hole 203, the area of ​​the gas permeable sheet 204 cannot be made larger than the opening area of ​​the gas communication hole 203. On the other hand, if the opening area of ​​the gas communication hole 203 is increased, the through hole for inserting the holder 202 also becomes larger, which leads to a decrease in the strength of the lid 201 and a decrease in the pressure resistance to the internal pressure of the battery. Therefore, in the pressure adjustment mechanism disclosed in Patent Document 1, there is a limit to enlarging the opening area of ​​the gas communication hole 203 by enlarging the through hole in order to increase the gas discharge speed.

[0009] In addition, when the gas permeable sheet is made thin, the variation in the film formation of the gas permeable sheet becomes significant, which increases the variation in the permeation rate, leading to a deterioration in the quality of the pressure adjustment mechanism. In addition, when the gas permeable sheet is made thin, it becomes difficult to hold the gas permeable sheet in the through hole by mechanical means using the elasticity of the sheet, such as crimping. In addition, it is possible to hold a thin gas permeable sheet in the through hole by adhesion using an adhesive such as double-sided tape, but since the adhesive is exposed to the organic electrolyte, it is not suitable for long-term retention. In addition, a method of welding the gas permeable sheet to the edge of the through hole with heat or ultrasound is also possible, but since it is a dissimilar material joint, it is difficult to guarantee the strength, and it is not suitable for long-term retention.

[0010] Thus, in order to achieve higher output, the rate at which the internal pressure rises is increased in a battery, and in the conventional technology, there is a problem that the pressure adjustment mechanism does not function adequately.

[0011] The nonaqueous electrolyte secondary battery according to the present disclosure is a nonaqueous electrolyte battery in which the opening of a battery case is sealed with a sealing plate, and includes a blind rivet that is inserted through a gas permeable membrane into an opening provided in the sealing plate and fixed to the sealing plate. The gas permeable membrane includes a bottomed cylindrical portion and an annular flange portion formed at an end of the cylindrical portion, and the blind rivet is composed of a sleeve body including a hollow cylindrical sleeve portion and an annular flange portion formed at an end of the sleeve portion, a shaft portion inserted into the hollow portion of the sleeve portion, and a mandrel including a head portion formed at the end of the shaft portion and having an outer diameter larger than the inner diameter of the hollow portion.

[0012] The blind rivet, with its sleeve portion and head covered by the tubular portion of the gas permeable membrane, is inserted into the opening, and the sleeve portion is crimped and fixed to the sealing plate. With the blind rivet fixed to the sealing plate, a space communicating with the outside of the battery case is formed between the gas permeable membrane and the blind rivet.

[0013] A method for manufacturing a nonaqueous electrolyte secondary battery according to the present disclosure is a method for manufacturing a nonaqueous electrolyte secondary battery in which an opening of a battery case is sealed with a sealing plate, and includes the steps of: (A) inserting a blind rivet into an opening provided in the sealing plate via a gas permeable membrane; and (B) crimping the blind rivet to fix the blind rivet to the sealing plate.

[0014] The blind rivet is composed of a sleeve body including a hollow tubular sleeve portion and an annular flange portion formed at the end of the sleeve portion, a shank portion inserted into the hollow portion of the sleeve portion, and a mandrel including a head portion formed at the end of the shank portion and having an outer diameter larger than the inner diameter of the hollow portion. The gas permeable membrane includes a bottomed tubular portion and an annular flange portion formed at the end of the tubular portion.

[0015] In step (A), the blind rivet is inserted into the opening with its sleeve portion and head covered by the tubular portion of the gas permeable membrane. Step (B) is performed by pulling the mandrel up from the sleeve portion while pressing the flange portion against the sealing plate. This causes the outer diameter of the sleeve portion to expand beyond the inner diameter of the opening, thereby fixing the blind rivet to the sealing plate. In step (B), with the blind rivet fixed to the sealing plate, a space communicating with the outside of the battery case is formed between the gas permeable membrane and the blind rivet.

[0016] According to the present disclosure, it is possible to provide a nonaqueous electrolyte secondary battery having a pressure adjustment mechanism with high gas exhaust capacity with a simple configuration, and a method for manufacturing a nonaqueous electrolyte secondary battery. [Brief description of the drawings]

[0017] [Figure 1] FIG. 1 is a perspective view illustrating a schematic diagram of a nonaqueous electrolyte secondary battery according to a first embodiment of the present disclosure. [Diagram 2] FIG. 2 is a cross-sectional view showing a schematic configuration of the blind rivet used in the first embodiment. [Diagram 3] FIG. 3 is a cross-sectional view showing a schematic configuration of the gas permeable membrane used in the first embodiment. [Figure 4] 4(A) to 4(D) are cross-sectional views illustrating a method for manufacturing the nonaqueous electrolyte secondary battery according to the first embodiment. [Diagram 5] FIG. 5 is an enlarged view showing the state in which the blind rivet is fixed to the sealing plate. [Figure 6] FIG. 6 is a diagram showing the configuration of another ventilation path for discharging the gas that has entered the space S1 to the outside. [Figure 7] FIG. 7 is a diagram showing the configuration of another ventilation path for discharging the gas that has entered the space S1 to the outside. [Figure 8] FIG. 8 is a cross-sectional view showing a schematic configuration of a blind rivet in the second embodiment of the present disclosure. [Figure 9] 9(A) to 9(D) are cross-sectional views illustrating a method for manufacturing a nonaqueous electrolyte secondary battery according to the second embodiment. [Figure 10] FIG. 10 is an enlarged view showing the state in which the blind rivet is fixed to the sealing plate. [Figure 11] FIG. 11 is a cross-sectional view showing the configuration of a conventional pressure adjustment mechanism. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. Note that the present invention is not limited to the following embodiment. In addition, appropriate modifications are possible without departing from the scope of the effects of the present invention.

[0019] (First embodiment) 1 is a perspective view showing a non-aqueous electrolyte secondary battery according to a first embodiment of the present disclosure. The non-aqueous electrolyte secondary battery according to this embodiment is a battery using a "non-aqueous system" such as an organic electrolyte or an organic solvent as an electrolyte, and the type is not particularly limited. A representative example of a non-aqueous electrolyte secondary battery is a lithium ion secondary battery.

[0020] 1, in a nonaqueous electrolyte secondary battery 100, an electrode body is housed in a battery case 1, and the opening of the battery case 1 is sealed with a sealing plate 2. The electrode body has a structure in which a positive electrode and a negative electrode are wound or stacked with a separator interposed therebetween. The positive electrode, negative electrode, and separator may be any known material.

[0021] A positive electrode external terminal 3, a negative electrode external terminal 4, an explosion-proof valve 5, and a blind rivet 10 are fixed to the sealing plate 2. The positive electrode external terminal 3 and the negative electrode external terminal 4 are connected to the positive electrode and the negative electrode of the electrode body, respectively. The explosion-proof valve 5 releases gas within the battery when the pressure within the battery case rises to or exceeds a predetermined value. The blind rivet 10 is inserted into a liquid injection hole (opening) provided in the sealing plate 2 and fixed thereto.

[0022] FIG. 2 is a cross-sectional view showing a schematic configuration of a blind rivet 10 used in this embodiment.

[0023] As shown in Fig. 2, the blind rivet 10 is composed of a sleeve body 11 and a mandrel 12. The sleeve body 11 includes a hollow cylindrical sleeve portion 11a and an annular flange portion 11b formed at the end of the sleeve portion 11a. The mandrel 12 includes a shank portion 12a inserted into the hollow portion of the sleeve portion 11a, and a head portion 12b formed at the end of the shank portion 12a and having an outer diameter larger than the inner diameter of the hollow portion of the sleeve portion 11a. The mandrel 12 has a through hole 12c penetrating in the axial direction, and a notch 12d is formed on the outer periphery of the shank portion 12a.

[0024] FIG. 3 is a cross-sectional view that illustrates a schematic configuration of the gas permeable membrane 20 used in this embodiment.

[0025] As shown in Fig. 3, the gas permeable membrane 20 includes a bottomed cylindrical portion 20a and an annular flange portion 20b formed at the end of the cylindrical portion 20a. The gas permeable membrane 20 is a selectively permeable membrane that selectively allows gas generated in the battery case 1 to pass therethrough. For example, in the case of a lithium ion secondary battery, examples of the gas generated in the battery case 1 include hydrogen, carbon dioxide, oxygen, and the like. In the case of a lithium ion secondary battery, it is preferable to use a gas permeable membrane 20 that does not allow moisture to pass therethrough.

[0026] The material of the gas permeable membrane 20 is not particularly limited, but for example, fluororesins such as polytetrafluoroethylene (PTFE) are preferred as materials for the gas permeable membrane 20 of lithium ion secondary batteries because they have high heat resistance, chemical resistance, gas permeability, and moisture permeation inhibition. In addition, perfluoroalkoxy fluororesin (PFA) and tetrafluoroethylene-hexafluoropropylene copolymer (FEP) can be formed by injection molding, so that the gas permeable membrane 20 can be obtained with a stable shape.

[0027] 4(A) to 4(D) are cross-sectional views illustrating a method for manufacturing a nonaqueous electrolyte secondary battery in this embodiment.

[0028] First, after the electrode body is accommodated in the battery case 1, the opening of the battery case 1 is sealed with a sealing plate 2. A positive electrode external terminal 3 and a negative electrode external terminal 4 are fixed in advance to the sealing plate 2. Then, an electrolyte is injected into the battery case 1 through an injection hole provided in the sealing plate 2.

[0029] 4(A), the blind rivet 10 shown in Fig. 2 is inserted into the liquid inlet (opening) 6 provided in the sealing plate 2 via the gas permeable membrane 20 shown in Fig. 3. Specifically, the blind rivet 10 is inserted into the liquid inlet 6 with the sleeve portion 11a of the sleeve body 11 and the head 12b of the mandrel 12 covered by the tubular portion 20a of the gas permeable membrane 20.

[0030] 4(B) shows a state in which the blind rivet 10 has been inserted into the liquid injection hole 6. The flange portion 11b of the sleeve body 11 abuts against the upper surface of the sealing plate 2 via the flange portion 20b of the gas permeable membrane 20.

[0031] 4(C), the blind rivet 10 is crimped to fix the blind rivet 10 to the sealing plate 2. Specifically, the blind rivet 10 is crimped by pulling the mandrel 12 up from the sleeve portion 11a while pressing the flange portion 11b against the sealing plate 2.

[0032] At this time, head 12b of mandrel 12 is pulled up while deforming sleeve portion 11a. This causes the outer diameter of sleeve portion 11a to expand beyond the inner diameter of injection hole 6, and expanded portion 11c is pressed against sealing plate 2. As a result, blind rivet 10 is fixed to sealing plate 2.

[0033] Furthermore, the expansion of the outer diameter of the sleeve portion 11a also expands the outer diameter of the tubular portion 20a of the gas permeable membrane 20. As a result, the gas permeable membrane 20 is fixed to the sealing plate 2 in a state where it is sandwiched between the expansion portion 11c of the sleeve portion 11a and the sealing plate 2.

[0034] Furthermore, when the mandrel 12 is pulled up, as shown in FIG. 4(D), the shaft portion 12a is broken at the location where the notch 12d is formed, and the remaining portion remains inside the sleeve portion 11a.

[0035] FIG. 5 is an enlarged view showing the blind rivet 10 fixed to the sealing plate 2. As shown in FIG.

[0036] 5, with the blind rivet 10 fixed to the sealing plate 2, a space S1 is formed between the gas permeable membrane 20 and the blind rivet 10. The space S1 communicates with the outside of the battery case 1 via a through hole 12c provided in the mandrel 12. As a result, gas generated inside the battery case 1 permeates the gas permeable membrane 20 and enters the space S1, and is then discharged to the outside of the battery case 1 through the through hole 12c.

[0037] In this embodiment, the outer diameter of the cylindrical portion 20a of the gas permeable membrane 20 is expanded, so that the area of ​​the gas permeable membrane 20 facing the space S1 is increased. This increases the discharge speed of the gas that passes through the gas permeable membrane 20 and is discharged to the outside of the battery case 1. As a result, a nonaqueous electrolyte secondary battery equipped with a pressure adjustment mechanism with high gas exhaust capacity can be realized. In particular, the pressure adjustment mechanism can function sufficiently even for a battery in which the internal pressure rise speed is increased due to an attempt to increase the output.

[0038] The pressure adjustment mechanism in this embodiment can be formed simply by inserting blind rivet 10 covered with gas permeable membrane 20 into injection hole 6, and then crimping blind rivet 10 to fix it to sealing plate 2. Therefore, a pressure adjustment mechanism with high gas exhaust capacity can be realized with a simple configuration.

[0039] Even though the through hole 12c provided in the mandrel 12 has a very small diameter (for example, a diameter of 0.1 mm or less), it has sufficient gas exhaust capacity for gas generated inside the battery case 1. Therefore, there is no need to increase the diameter of the through hole 12c, and therefore no need to increase the outer diameter of the blind rivet 10. As a result, there is no need to increase the diameter of the liquid injection hole 6 through which the blind rivet 10 is inserted, and so the strength of the sealing plate 2 is not reduced.

[0040] Furthermore, in this embodiment, the blind rivet 10 is fixed to the sealing plate 2 by crimping, so that when the blind rivet 10 is inserted into the liquid filling hole 6, foreign matter generated by friction or the like does not enter the battery case.

[0041] As described above, the nonaqueous electrolyte secondary battery 100 in this embodiment is a nonaqueous electrolyte battery in which the opening of the battery case 1 is sealed with the sealing plate 2, and is provided with the blind rivet 10 that is inserted through the gas permeable membrane 20 into the liquid injection hole (opening) 6 provided in the sealing plate 2 and fixed to the sealing plate 2.

[0042] The gas permeable membrane 20 includes a cylindrical portion 20a having a bottom and an annular flange portion 20b formed at the end of the cylindrical portion 20a. The blind rivet 10 is composed of a sleeve body 11 including a hollow cylindrical sleeve portion 11a and an annular flange portion 11b formed at the end of the sleeve portion 11a, and a mandrel 12 including a shank portion 12a inserted into the hollow portion of the sleeve portion 11a, and a head portion 12b formed at the end of the shank portion 12a and having an outer diameter larger than the inner diameter of the hollow portion.

[0043] The blind rivet 10 is inserted into the liquid injection hole (opening) 6 with the sleeve portion 11a and head portion 12b covered by the tubular portion 20a of the gas permeable membrane 20, and the sleeve portion 11a is crimped and fixed to the sealing plate 2. With the blind rivet 10 fixed to the sealing plate 2, a space S1 communicating with the outside of the battery case 1 is formed between the gas permeable membrane 20 and the blind rivet 10.

[0044] Furthermore, the manufacturing method for the nonaqueous electrolyte secondary battery in this embodiment includes a step (A) of inserting blind rivet 10 through gas permeable membrane 20 into injection hole (opening) 6 provided in sealing plate 2, and a step (B) of crimping blind rivet 10 to fix blind rivet 10 to sealing plate 2.

[0045] In step (A), the blind rivet 10 is inserted into the liquid injection hole (opening) 6 with the sleeve portion 11a and head portion 12b covered with the tubular portion 20a of the gas permeable membrane 20.

[0046] Step (B) is performed by pulling the mandrel 12 up from the sleeve portion 11a while pressing the flange portion 11b against the sealing plate 2, thereby expanding the outer diameter of the sleeve portion 11a beyond the inner diameter of the liquid injection hole (opening portion) 6, thereby fixing the blind rivet 10 to the sealing plate 2.

[0047] In step (B), with the blind rivet 10 fixed to the sealing plate 2, a space S1 that communicates with the outside of the battery case 1 is formed between the gas permeable membrane 20 and the blind rivet 10.

[0048] (Modification) In the above embodiment, as shown in FIG. 5, the gas that has entered the space S1 formed between the gas permeable membrane 20 and the blind rivet 10 is discharged to the outside through the through hole 12c provided in the mandrel 12.

[0049] FIG. 6 is a diagram showing the configuration of another ventilation path for discharging the gas that has entered the space S1 to the outside, without providing the through-hole 12c.

[0050] As shown in Fig. 6, in this modification, a vertical groove 11d is formed on the outer periphery at the tip of the sleeve portion 11a. Meanwhile, a space S2 that is open to the outside is formed between the sleeve portion 11a and the shaft portion 12a of the mandrel 12. Therefore, the space S1 can be communicated with the space S2 via the vertical groove 11d. As a result, gas that has entered the space S1 can be discharged to the outside via the vertical groove 11d and the space S2 as a ventilation path.

[0051] 7, a lateral groove 12e may be formed on the upper surface of the head 12b of the mandrel 12. In this case, the space S1 can be connected to the space S2 via the lateral groove 12e. This allows gas that has entered the space S1 to be discharged to the outside through the lateral groove 12e and the space S2 as a ventilation path.

[0052] Second embodiment FIG. 8 is a cross-sectional view showing a schematic configuration of a blind rivet in the second embodiment of the present disclosure.

[0053] As shown in Fig. 8, the blind rivet 10 in this embodiment is composed of a sleeve body 11 and a mandrel 12. The sleeve body 11 includes a hollow cylindrical sleeve portion 11a and an annular flange portion 11b formed at the end of the sleeve portion 11a. The mandrel 12 includes a shank portion 12a inserted into the hollow portion of the sleeve portion 11a, and a head portion 12b formed at the end of the shank portion 12a and having an outer diameter larger than the inner diameter of the hollow portion of the sleeve portion 11a. The mandrel 12 also has a through hole 12c that passes through in the axial direction. A notch 12d is formed on the outer periphery of the shank portion 12a.

[0054] This embodiment differs from the structure shown in the first embodiment (FIG. 5) in that the head 12b has an inclined surface 12f on the end side of the sleeve portion 11a.

[0055] 9(A) to 9(D) are cross-sectional views illustrating a method for manufacturing a nonaqueous electrolyte secondary battery in this embodiment.

[0056] 9(A), the blind rivet 10 shown in Fig. 8 is inserted into the liquid inlet (opening) 6 provided in the sealing plate 2 via the gas permeable membrane 20 shown in Fig. 3. Specifically, the blind rivet 10 is inserted into the liquid inlet 6 with the sleeve portion 11a of the sleeve body 11 and the head 12b of the mandrel 12 covered by the tubular portion 20a of the gas permeable membrane 20.

[0057] 9(B) shows a state in which the blind rivet 10 has been inserted into the liquid injection hole 6. The flange portion 11b of the sleeve body 11 abuts against the upper surface of the sealing plate 2 via the flange portion 20b of the gas permeable membrane 20.

[0058] 9(C), the blind rivet 10 is crimped to fix the blind rivet 10 to the sealing plate 2. Specifically, the blind rivet 10 is crimped by pulling the mandrel 12 up from the sleeve portion 11a while pressing the flange portion 11b against the sealing plate 2.

[0059] At this time, head 12b of mandrel 12 is pulled up while deforming sleeve portion 11a. This causes the outer diameter of sleeve portion 11a to expand beyond the inner diameter of injection hole 6, and the expanded portion is pressed against sealing plate 2. As a result, blind rivet 10 is fixed to sealing plate 2.

[0060] As shown in FIG. 4(C), in the first embodiment, the sleeve portion 11a is expanded while being folded, but in this embodiment, the sleeve portion 11a is expanded while being deformed into an arc shape.

[0061] The expansion of the outer diameter of the sleeve portion 11a also expands the outer diameter of the tubular portion 20a of the gas permeable membrane 20. As a result, the gas permeable membrane 20 is fixed to the sealing plate 2 in a state where it is sandwiched between the expansion portion 11c of the sleeve portion 11a and the sealing plate 2.

[0062] Furthermore, when the mandrel 12 is pulled up, as shown in FIG. 9(D), the shaft portion 12a is broken at the location where the notch 12d is formed, and the remaining portion remains inside the sleeve portion 11a.

[0063] FIG. 10 is an enlarged view showing the blind rivet 10 fixed to the sealing plate 2. As shown in FIG.

[0064] 10, with the blind rivet 10 fixed to the sealing plate 2, a space S1 is formed between the gas permeable membrane 20 and the blind rivet 10. The space S1 communicates with the outside of the battery case 1 via a through hole 12c provided in the mandrel 12. As a result, gas generated inside the battery case 1 permeates the gas permeable membrane 20 and enters the space S1, and is then discharged to the outside of the battery case 1 through the through hole 12c.

[0065] In this embodiment, the outer diameter of the cylindrical portion 20a of the gas permeable membrane 20 is expanded, so that the area of ​​the gas permeable membrane 20 facing the space S1 is increased. This increases the discharge rate of the gas that permeates the gas permeable membrane 20 and is discharged to the outside of the battery case 1. As a result, a nonaqueous electrolyte secondary battery having a pressure adjustment mechanism with high gas exhaust capacity can be provided. In particular, the pressure adjustment mechanism can function sufficiently for a battery with high output and an increased internal pressure rise rate.

[0066] Furthermore, in this embodiment, since the sleeve portion 11a is not folded, the length of the sleeve portion 11a before crimping can be made shorter than that in the first embodiment.

[0067] In this embodiment, instead of providing a through hole 12c in the mandrel 12, a groove can be formed on the inner circumference of the sleeve portion 11a or on the inclined surface 12f of the head 12b of the mandrel 12, as shown in Figure 6 or Figure 7, so that gas that has entered the space S1 can be discharged to the outside.

[0068] Although the present invention has been described above with reference to the preferred embodiments, such description is not limiting and, of course, various modifications are possible.

[0069] For example, in the above embodiment, the deformation of the sleeve portion 11a when the mandrel 12 is pulled up from the sleeve portion 11a is exemplified by folding (Figure 4(C)) or deforming into an arc shape (Figure 9(C)). However, this is not limited to these, and the sleeve portion 11a may be deformed into any shape as long as the outer diameter of the sleeve portion 11a is expanded larger than the inner diameter of the liquid injection hole 6.

[0070] In addition, in the above embodiment, the blind rivet is inserted into the liquid injection hole 6 and fixed to the sealing plate 2, but it may also be inserted into an opening provided in the sealing plate 2 separately from the liquid injection hole 6 and fixed to the sealing plate 2.

[0071] Furthermore, in the above embodiment, as shown in FIG. 4(A), the blind rivet 10 was inserted into the liquid inlet 6 while covered with the gas permeable membrane 20, but the blind rivet 10 may be inserted into the tubular portion 20a of the gas permeable membrane 20 after the gas permeable membrane 20 is inserted into the liquid inlet 6.

[0072] Furthermore, in the above embodiment, the materials of the sleeve body 11 and mandrel 12 that constitute the blind rivet 10 are not particularly limited. [Explanation of symbols]

[0073] 1 Battery case 2 Sealing plate 3 Positive external terminal 4 Negative external terminal 5 Explosion-proof valve 6 Liquid injection hole (opening part) 10 Blind Rivet 11 Sleeve body 11a Sleeve section 11b Flange part 11c Extension 11d vertical groove 12 Mandrel 12a Shaft 12b Head 12c through hole 12d notch 12e Yokomizo 12f slope 20 Gas permeable membrane 20a Cylindrical part 20b Tsubabe 100 Nonaqueous electrolyte secondary battery S1, S2 space

Claims

1. A nonaqueous electrolyte battery in which an opening of a battery case is sealed with a sealing plate, a blind rivet that is inserted into an opening in the sealing plate through a gas permeable membrane and fixed to the sealing plate; The gas permeable membrane includes a bottomed cylindrical portion and an annular flange portion formed at an end of the cylindrical portion, The blind rivet is a sleeve body including a hollow cylindrical sleeve portion and an annular flange portion formed at an end of the sleeve portion; a mandrel including a shaft portion to be inserted into the hollow portion of the sleeve portion, and a head portion formed at an end of the shaft portion and having an outer diameter larger than an inner diameter of the hollow portion; It is composed of the blind rivet is inserted into the opening with the sleeve portion and the head portion covered by the tubular portion of the gas permeable membrane, and the sleeve portion is crimped and fixed to the sealing plate, a space communicating with the outside of the battery case is formed between the gas permeable membrane and the blind rivet when the blind rivet is fixed to the sealing plate.

2. The mandrel has a through hole extending therethrough in an axial direction, 2 . The nonaqueous electrolyte secondary battery according to claim 1 , wherein a space formed between the gas permeable membrane and the blind rivet communicates with the outside of the battery case via the through hole.

3. 2 . The nonaqueous electrolyte secondary battery according to claim 1 , wherein the tubular portion of the gas permeable membrane is fixed to the sealing plate in a state where it is sandwiched between the expansion portion of the sleeve portion and the sealing plate.

4. 2. The nonaqueous electrolyte secondary battery according to claim 1, wherein the gas permeable membrane is a selectively permeable membrane that selectively allows the passage of gas generated within the battery case.

5. 2. The nonaqueous electrolyte secondary battery according to claim 1, wherein the opening comprises an injection hole for injecting an electrolyte.

6. A method for manufacturing a nonaqueous electrolyte secondary battery in which an opening of a battery case is sealed with a sealing plate, comprising the steps of: A step (A) of inserting a blind rivet into an opening provided in the sealing plate via a gas permeable membrane; (B) a step of crimping the blind rivet to fix the blind rivet to the sealing plate; Equipped with The blind rivet is a sleeve body including a hollow cylindrical sleeve portion and an annular flange portion formed at an end of the sleeve portion; a mandrel including a shaft portion to be inserted into the hollow portion of the sleeve portion, and a head portion formed at an end of the shaft portion and having an outer diameter larger than an inner diameter of the hollow portion; It is composed of The gas permeable membrane includes a bottomed cylindrical portion and an annular flange portion formed at an end of the cylindrical portion, In the step (A), the blind rivet is inserted into the opening with the sleeve portion and the head portion covered with the tubular portion of the gas permeable membrane, the step (B) is carried out by pulling up the mandrel from the sleeve portion while pressing the flange portion against the sealing plate, whereby the outer diameter of the sleeve portion is expanded to be larger than the inner diameter of the opening portion, thereby fixing the blind rivet to the sealing plate; in the step (B), with the blind rivet fixed to the sealing plate, a space communicating with the outside of the battery case is formed between the gas permeable membrane and the blind rivet.

7. The mandrel has a through hole extending therethrough in an axial direction, 7. The method for producing a nonaqueous electrolyte secondary battery according to claim 6, wherein in the step (B), a space formed between the gas permeable membrane and the blind rivet communicates with the outside of the battery case via the through hole.

8. 7. The method for producing a nonaqueous electrolyte secondary battery according to claim 6, wherein in the step (B), the tubular portion of the gas permeable membrane is fixed to the sealing plate in a state where it is sandwiched between the expansion portion of the sleeve portion and the sealing plate.

9. 7. The method for producing a nonaqueous electrolyte secondary battery according to claim 6, wherein the gas permeable membrane is a selectively permeable membrane that selectively allows the gas generated in the battery case to pass therethrough.

10. The method for producing a nonaqueous electrolyte secondary battery according to claim 9 , wherein the gas permeable membrane is made of a fluororesin formed by injection molding.

11. the opening provided in the sealing plate is an injection hole for injecting an electrolyte, The method for producing a nonaqueous electrolyte secondary battery according to claim 6 , wherein the step (A) is performed after an electrolyte is injected into the battery case through the injection hole.

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