Cylindrical battery

Abstract

A cylindrical battery (10) is provided with: an outer can (16); an electrode body (14) accommodated in the outer can (16); and a sealing body (17) for sealing the opening of the outer can (16). The outer tank (16) is provided with: a bottom plate section (68); a cylindrical section (43) that extends in the axial direction and that is connected to the bottom plate section (68) via an annular ridge section (42) positioned on the outside in the radial direction; and a rewinding section (45) connected to an end of the cylindrical section (43) on the opposite side from the axial ridge section (42) side. The sealing body (17) has a rewinding section (31) in which an end section on the outside in the radial direction is fixed to the rewinding section (45).

Description

Technical Field

[0001] The present disclosure relates to cylindrical batteries. Background Art

[0002] In the past, as a cylindrical battery, there is a cylindrical battery described in Figure 3 of Patent Document 1. The cylindrical battery includes an outer can, an electrode body contained in the outer can, and a sealing body that blocks the opening of the outer can. The sealing body is riveted and fixed to the opening of the outer can via a gasket. The outer can has a shoulder, a groove, a cylindrical portion, and a bottom plate. The groove is formed by annularly recessing a portion of the side of the outer can toward the radial inside. Due to the formation of the groove, the sealing body receives an axial force on the opening side from the annular protrusion protruding toward the radial inside through the gasket. When the sealing body is riveted and fixed to the outer can, the upper end of the outer can is bent inward toward the peripheral edge of the sealing body, thereby forming a shoulder.

[0003] Prior Art Literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2000-48825 Summary of the invention

[0006] In the above cylindrical battery, since the outer can has a groove, the housing of the electrode body in the outer can is limited to a position closer to the bottom plate side of the outer can than the groove in the height direction (axial direction) of the cylindrical battery. Therefore, it is difficult to increase the housing of the electrode body and the battery capacity. To this end, the purpose of the present disclosure is to provide a cylindrical battery that can increase the housing of the electrode body and increase the battery capacity.

[0007] In order to solve the above-mentioned problems, the cylindrical battery involved in the present disclosure comprises: an outer can; an electrode body, which is accommodated in the outer can; and a sealing body, which seals the opening of the outer can, wherein the outer can has: a bottom plate portion; a cylindrical portion, which is connected to the bottom plate portion via an annular ridge portion located on the radially outer side and extends in the axial direction; and a first rewinding portion, which is connected to the end of the cylindrical portion on the axial side opposite to the ridge portion side, and the sealing body has: a second rewinding portion, whose radially outer end is fixed to the first rewinding portion.

[0008] According to the cylindrical battery according to the present disclosure, the housing portion of the electrode body can be enlarged, and the battery capacity can be increased. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 This is a cross-sectional view in the axial direction of a cylindrical battery according to one embodiment of the present disclosure.

[0010] Figure 2 It is a perspective view of an electrode body of a cylindrical battery.

[0011] Figure 3A This is a schematic cross-sectional view of a portion of a cylindrical battery of a comparative example for explaining a method for forming a shoulder portion in the cylindrical battery of the comparative example.

[0012] Figure 3B This is a schematic cross-sectional view of a portion of a cylindrical battery of a comparative example for explaining a method for forming a shoulder portion in the cylindrical battery of the comparative example.

[0013] Figure 4A This is a schematic cross-sectional view of a portion of a cylindrical battery according to an embodiment for explaining the rewinding caulking of the cylindrical battery according to the embodiment.

[0014] Figure 4B This is a schematic cross-sectional view of a portion of a cylindrical battery according to an embodiment for explaining the rewinding caulking of the cylindrical battery according to the embodiment.

[0015] Figure 4C A cylindrical battery of a modified example Figure 4B Corresponding schematic cross-sectional view.

[0016] Figure 5A It is a diagram showing the details of the battery height at various locations in the battery of the example.

[0017] Figure 5B It is a diagram showing the details of the battery height at various locations in the battery of the comparative example.

[0018] Figure 6 It is an enlarged cross-sectional view of the periphery of the shoulder of a cylindrical battery of a reference example.

[0019] Figure 7 The cylindrical battery of the embodiment Figure 6 Corresponding enlarged cross-sectional view. DETAILED DESCRIPTION

[0020] Hereinafter, the embodiment of the cylindrical battery involved in the present disclosure will be described in detail with reference to the accompanying drawings. In addition, the cylindrical battery of the present disclosure may be either a primary battery or a secondary battery. In addition, it may be either a battery using an aqueous electrolyte or a battery using a non-aqueous electrolyte. Hereinafter, as a cylindrical battery 10 of one embodiment, a non-aqueous electrolyte secondary battery (lithium ion battery) using a non-aqueous electrolyte is exemplified, but the cylindrical battery of the present disclosure is not limited thereto.

[0021] It was envisaged from the beginning that the characteristic parts of the embodiments and variants described below would be appropriately combined to construct new embodiments. In the following embodiments, the same symbols are given to the same structures in the drawings, and repeated descriptions are omitted. In addition, schematic diagrams are included in multiple drawings, and the dimension ratios of the vertical, horizontal, and height of each component may not be consistent between different drawings. In this specification, the axial (height direction) side of the sealing body 17 of the cylindrical battery 10 is set to "upper", and the axial side of the bottom plate 68 of the outer can 16 is set to "lower". In addition, among the structural elements described below, the structural elements that are not recorded in the independent claims representing the highest concept are arbitrary structural elements and are not necessary structural elements. In addition, the present disclosure is not limited to the following embodiments and their variants, and various improvements and changes can be made within the scope of the matters recorded in the claims of this application and their equivalents.

[0022] Figure 1 is a cross-sectional view in the axial direction of a cylindrical battery 10 according to one embodiment of the present disclosure. Figure 2 FIG. 1 is a perspective view of the electrode body 14 of the cylindrical battery 10. Figure 1 As shown, the cylindrical battery 10 includes a wound electrode body 14, a non-aqueous electrolyte (not shown), a bottomed cylindrical metal outer can 16 that accommodates the electrode body 14 and the non-aqueous electrolyte, and a sealing body 17 that seals the opening of the outer can 16. Figure 2 As shown, the electrode body 14 has a wound structure in which a long positive electrode 11 and a long negative electrode 12 are wound with two long separators 13 interposed therebetween.

[0023] In order to prevent the precipitation of lithium, the negative electrode 12 is formed to be one size larger than the positive electrode 11. That is, the negative electrode 12 is formed to be longer than the positive electrode 11 in the long side direction and the width direction (short side direction). In addition, the two separators 13 are formed to be at least one size larger than the positive electrode 11, for example, arranged to sandwich the positive electrode 11. The negative electrode 12 may also constitute the winding start end of the electrode body 14. However, generally, the separator 13 extends beyond the winding start side end of the negative electrode 12, and the winding start side end of the separator 13 becomes the winding start end of the electrode body 14.

[0024] The non-aqueous electrolyte includes a non-aqueous solvent and an electrolyte salt dissolved in the non-aqueous solvent. For the non-aqueous solvent, for example, esters, ethers, nitriles, amides, and mixed solvents of two or more thereof may be used. The non-aqueous solvent may also contain a halogen substituted body in which at least a portion of the hydrogen atoms of these solvents are replaced with halogen atoms such as fluorine. In addition, the non-aqueous electrolyte is not limited to a liquid electrolyte, and may also be a solid electrolyte using a gel-like polymer or the like. For the electrolyte salt, a lithium salt such as LiPF6 may be used.

[0025] The positive electrode 11 has a positive electrode collector and a positive electrode composite layer formed on both sides of the positive electrode collector. For the positive electrode collector, a metal foil such as aluminum or aluminum alloy that is stable within the potential range of the positive electrode 11, a thin film that arranges the metal on the surface, etc. can be used. The positive electrode composite layer contains a positive electrode active material, a conductive agent, and a binder. For example, a positive electrode composite slurry containing a positive electrode active material, a conductive agent, and a binder is applied to the positive electrode collector, and the coating is compressed after drying, and the positive electrode composite layer is formed on both sides of the collector, thereby making the positive electrode 11.

[0026] The positive electrode active material is composed of a lithium-containing metal composite oxide as a main component. As the metal elements contained in the lithium-containing metal composite oxide, Ni, Co, Mn, Al, B, Mg, Ti, V, Cr, Fe, Cu, Zn, Ga, Sr, Zr, Nb, In, Sn, Ta, W, etc. can be listed. An example of a preferred lithium-containing metal composite oxide is a composite oxide containing at least one of Ni, Co, Mn, and Al.

[0027] As the conductive agent included in the positive electrode composite layer, carbon materials such as carbon black, acetylene black, Ketjen black, and graphite can be exemplified. As the binder included in the positive electrode composite layer, fluororesins such as polytetrafluoroethylene (PTFE) and polyvinylidene fluoride (PVdF), polyacrylonitrile (PAN), polyimide resin, acrylic resin, polyolefin resin, etc. can be exemplified. These resins can be used in combination with cellulose derivatives such as carboxymethyl cellulose (CMC) or its salt, polyethylene oxide (PEO), etc.

[0028] The negative electrode 12 has a negative electrode collector and a negative electrode composite layer formed on both sides of the negative electrode collector. For the negative electrode collector, a metal foil such as copper or copper alloy that is stable within the potential range of the negative electrode 12, a film that arranges the metal on the surface, etc. can be used. The negative electrode composite layer contains a negative electrode active material and a binder. For example, a negative electrode composite slurry containing a negative electrode active material and a binder is applied to the negative electrode collector, and after the coating is dried, it is compressed to form the negative electrode composite layer on both sides of the collector, thereby making it possible to produce the negative electrode 12.

[0029] For the negative electrode active material, generally, a carbon material that can reversibly absorb and release lithium ions is used. Preferred carbon materials are graphites such as natural graphites such as flaky graphite, blocky graphite, and earthy graphite, blocky artificial graphite, and artificial graphites such as graphitized mesophase carbon microbeads. For the negative electrode composite layer, as the negative electrode active material, a Si material containing silicon (Si) may also be included. In addition, for the negative electrode active material, metals other than Si that are alloyed with lithium, alloys containing the metal, compounds containing the metal, etc. may also be used.

[0030] As for the binder contained in the negative electrode composite layer, fluororesin, PAN, polyimide resin, acrylic resin, polyolefin resin, etc. may be used as in the case of the positive electrode 11, but styrene-butadiene rubber (SBR) or its modified form is preferably used. For example, in addition to SBR, the negative electrode composite layer may also contain CMC or its salt, polyacrylic acid (PAA) or its salt, polyvinyl alcohol, etc.

[0031] For the separator 13, a porous sheet having ion permeability and insulation can be used. Specific examples of the porous sheet include microporous films, woven fabrics, non-woven fabrics, etc. The material of the separator 13 is preferably a polyolefin resin such as polyethylene and polypropylene, cellulose, etc. The separator 13 can be either a single-layer structure or a laminated structure. A heat-resistant layer, etc., can also be formed on the surface of the separator 13.

[0032] like Figure 1 As shown, a positive electrode lead 20 is joined to the positive electrode 11, and a negative electrode lead 21 is joined to the end of the winding end side of the negative electrode 12 in the long side direction. The cylindrical battery 10 has an upper insulating plate 18 above the electrode body 14 and a lower insulating plate 19 below the electrode body 14. The positive electrode lead 20 extends to the sealing body 17 side through the through hole of the upper insulating plate 18, and the negative electrode lead 21 extends to the bottom plate 68 side of the outer can 16 through the outer side of the lower insulating plate 19. The positive electrode lead 20 is connected to the lower surface of the terminal cover 27 of the sealing body 17 by welding or the like, and the terminal cover 27 serves as a positive terminal. In addition, the negative electrode lead 21 is connected to the inner surface of the bottom plate 68 of the metal outer can 16 by welding or the like, and the outer can 16 serves as a negative terminal.

[0033] exist Figure 1 as well as Figure 2 In the example shown, the positive electrode lead 20 is electrically connected to an intermediate portion such as the center portion in the winding direction of the positive electrode collector, and the negative electrode lead 21 is electrically connected to the end portion of the winding end side of the winding direction of the negative electrode collector. However, the negative electrode lead may be electrically connected to the end portion of the winding start side of the winding direction of the negative electrode collector. Alternatively, the electrode body may have two negative electrode leads, one negative electrode lead is electrically connected to the end portion of the winding start side of the winding direction of the negative electrode collector, and the other negative electrode lead is electrically connected to the end portion of the winding end side of the winding direction of the negative electrode collector. Alternatively, the negative electrode and the outer can may be electrically connected by bringing the end portion of the winding end side of the winding direction of the negative electrode collector into contact with the inner surface of the outer can. Alternatively, the negative electrode lead may be electrically connected to the end portion of the winding start side of the winding direction of the negative electrode collector, and the end portion of the winding end side of the winding direction of the negative electrode collector may be brought into contact with the inner surface of the outer can.

[0034] The outer can 16 has a bottom plate 68, an annular ridge 42 connected to the radially outer end of the bottom plate 68 and bent axially upward, a cylindrical cylindrical portion 43 extending axially upward from the side of the ridge 42 opposite to the bottom plate 68, and a reel 45 connected to the axially upper end of the cylindrical portion 43. In addition, the sealing body 17 has a gasket 23 constituting an annular first metal member, an annular packing 28 having insulating properties, and a terminal cover 27. The packing 28 constitutes an insulating member, and the terminal cover 27 constitutes a second metal member. The gasket 23 has a reel 31 at the radially outer end, and has an annular groove 32 opened radially inward at the radially inner end. The reel 31 of the gasket 23 is fixed to the reel 45 of the outer can 16.

[0035] Specifically, the roll-back fixing structure 80 of the roll-back portion 45 of the outer can 16 and the roll-back portion 31 of the gasket 23 is formed by roll-back caulking, and the roll-back portion 45 of the outer can 16 and the roll-back portion 31 of the gasket 23 are formed simultaneously by roll-back caulking. Figure 3A as well as Figure 3B 2 is a schematic cross-sectional view of a portion of a cylindrical battery 210 for explaining a method for forming a shoulder portion 238 in a cylindrical battery 210 of a comparative example. Figure 4A as well as Figure 4B 1 is a schematic cross-sectional view of a portion of the cylindrical battery 10 for explaining the rewinding and caulking of the cylindrical battery 10 .

[0036] like Figure 3A as well as Figure 3B As shown, the cylindrical battery 210 has a groove 234 that is annularly recessed toward the radial inner side in the outer can 216, and thus, an annular protrusion 236 that protrudes toward the radial inner side is provided in the cylindrical battery 210. The shoulder 238 of the cylindrical battery 210 (see Figure 3B ) is formed as follows. First, Figure 3A As shown in FIG. 1 , a stacked structure of a terminal cover 227 and a break plate 225 constituting the peripheral edge of the sealing body 217 is arranged on the axial upper side of the annular protrusion 236 in the outer can 216 via a gasket 228. Then, the upper end 216a of the outer can 216 is riveted and bent inward toward the peripheral edge 245 of the sealing body 217 as indicated by the arrow A. In this way, as shown in FIG. Figure 3B As shown, the shoulder 238 of the cylindrical battery 210 is formed, and the peripheral edge 245 of the sealing body 217 is sandwiched by the shoulder 238 and the annular protrusion 236 via the gasket 228 to seal the opening of the outer can 216.

[0037] On the other hand, in the cylindrical battery 10, the winding and fixing structure 80 is formed as follows. First, Figure 4AAs shown in FIG. 1 , the radially outer end of the gasket 23 that has expanded in the radial direction is folded back toward the axial upper side, and a cylindrical portion 51 is formed on the radially outer side of the gasket 23. Next, the cylindrical portion 51 is inserted into the cylindrical portion 43 of the outer can 16 by press-fitting, etc., so that the cylindrical outer circumference of the cylindrical portion 51 abuts against the cylindrical inner circumference of the cylindrical portion 43 of the outer can 16. Thereafter, the cylindrical portion that has been double-overlapped in the radial direction is rolled back more than 360 degrees toward the radial inner side in the direction indicated by the arrow B, thereby forming a cylindrical portion 51. Figure 4B A rewind securement configuration 80 is shown.

[0038] In addition, in the present embodiment, the rewinding fixing structure 80 is formed by rewinding the cylindrical portion double-overlapped in the radial direction more than 360 degrees inward in the radial direction, but the cylindrical portion double-overlapped in the radial direction may not be rewinded more than 360 degrees. Figure 4C That is, the cylindrical battery 110 of the modified example Figure 4B As shown in the corresponding schematic cross-sectional view, the radially inner side of the double-overlapped cylindrical portion can be rolled back in a state where the cross section of the rolled portion 145 of the outer can 116 is approximately U-shaped, and the cross section of the rolled portion 131 of the gasket 123 is approximately U-shaped. In this way, the outer can 116 and the gasket 123 can be sealed and fixed using a double roll seal used in can sealing, etc.

[0039] Refer again Figure 1 The rewinding portion 45 of the outer can 16 has a first planar portion 83 extending in an orthogonal direction substantially orthogonal to the axial direction at the front end in the axial direction. In addition, the terminal cover 27 has a second planar portion 85 extending in an orthogonal direction substantially orthogonal to the axial direction at the front end in the axial direction. The axial position of the first planar portion 83 is substantially the same as the axial position of the second planar portion 85. The gasket 28 is an annular member. The gasket 28 includes an accommodating portion 28a accommodated in the annular groove 32 of the gasket 23. The gasket 28 has an annular groove 39 opening radially inward. The radially outer outer edge portion of the terminal cover 27 is accommodated in the annular groove 39.

[0040] The gasket 28 is sandwiched between the gasket 23 and the terminal cover 27, and insulates the terminal cover 27 from the gasket 23. The gasket 28 has the function of a sealing material for maintaining the airtightness inside the battery, and a function of an insulating material for insulating the terminal cover 27 from the gasket 23. When the cylindrical battery 10 is manufactured, the terminal cover 27, the gasket 28, and the gasket 23 are integrated and combined, and then the gasket 28 is used. Figure 4A as well as Figure 4B The opening of the outer can 16 is sealed by the aforementioned rewinding and caulking.

[0041] A circular thin-walled portion 71 centered on the radial center of the bottom plate portion 68 is provided on the bottom surface 68a of the outer can 16. The thin-walled portion 71 constitutes an easily broken portion. The portion of the bottom plate portion 68 surrounded by the circular thin-walled portion 71 constitutes a safety valve 72. It is formed so that when the cylindrical battery 10 is abnormally heated, the thin-walled portion 71 is broken. In this way, an opening is formed at the location where the safety valve 72 exists, and the high-temperature gas in the battery is discharged to the outside. In addition, in this embodiment, the case where the easily broken portion is constituted by the circular thin-walled portion 71 is described, but for example, the easily broken portion can also be constituted by providing a C-shaped thin-walled portion on the bottom side of the bottom plate portion. The easily broken portion is not limited to a circular or C-shaped portion as long as an opening can be formed at the location where the safety valve 72 exists.

[0042] <Example>

[0043] Produced Figure 1 The cylindrical battery shown. A gasket is installed on the terminal cover, and the gasket is riveted and crimped onto the gasket, thereby producing a sealing body. The positive electrode, negative electrode, separator, positive electrode lead, and negative electrode lead are used to produce an electrode body, and the electrode body is inserted into the outer can. The outer can is not grooved. The electrolyte is injected into the outer can. Thereafter, the outer edge of the outer can and the sealing body are wound and riveted, and the opening of the outer can is sealed by the sealing body, thereby producing a cylindrical lithium-ion battery.

[0044] <Comparative Example>

[0045] Produced Figure 5B The cylindrical battery shown. The electrode body 214 is made using a positive electrode, a negative electrode, a separator, a positive electrode lead, and a negative electrode lead, and the electrode body 214 is inserted into an outer can 216. The bottom plate portion of the outer can 216 and the negative electrode lead are welded to form a groove portion 234. The gasket 228 is inserted, and the positive electrode lead and the sealing body 217 are welded, and then the electrolyte is injected into the outer can 216. Next, the upper end of the outer can 216 is bent radially inward by riveting to form a shoulder 238, thereby sealing the opening of the outer can 216 by the sealing body 217 to produce a cylindrical lithium-ion battery. The sealing body 217 is made by welding the terminal cover 227, the break plate 225 and the terminal plate 229.

[0046] [Battery height details]

[0047] [Table 1]

[0048]

[0049] Table 1 shows the ratio of each structure to the total length of the battery in the cylindrical battery 10 of the embodiment and the cylindrical battery 210 of the comparative example. Figure 5AThe height of each part of the cylindrical battery 10 of the embodiment is shown in detail. Figure 5B The height of each part of the cylindrical battery 210 of the comparative example is shown in detail. Figure 5A , Figure 5B As shown in Table 1, in the cylindrical battery 10 of the embodiment, the structure of the sealing body 17 is simpler than that of the sealing body 217 of the cylindrical battery 210 of the comparative example, and the thickness of the sealing body 17 can be reduced by 1.0% of the total length of the battery compared with the sealing body 217 of the comparative example. Furthermore, in the cylindrical battery 10 of the embodiment, unlike the cylindrical battery 210 of the comparative example, since there is no groove 234, a space of 2.4% of the total length of the battery can be further used to accommodate the electrode body 14. Accordingly, compared with the electrode body 214 of the comparative example, the axial height of the electrode body 14 can be increased by 3.4% of the total length of the battery, and as a result, the battery capacity can be significantly increased.

[0050] [Advantages when making battery packs]

[0051] Sometimes, multiple cylindrical batteries are electrically connected to make a battery pack with a large output and capacity. When making a battery pack, lead tabs are welded to the positive and negative electrodes of the battery, but from the perspective of ease of welding, lead tabs are usually welded to the top surface of the sealing body (positive electrode) and the bottom of the can (negative electrode) for current collection. However, from the perspective of improving productivity, it is preferred if the lead tabs can be welded to the top surface of the sealing body (positive electrode) and the shoulder of the battery (negative electrode) for current collection.

[0052] However, if Figure 6 That is, as shown in the enlarged cross-sectional view of the periphery of the shoulder 238 of the cylindrical battery 210 of the reference example, in the cylindrical battery 210, there is a gasket 228 near the shoulder 238. Therefore, if the lead tab 290 for connecting the negative electrode is to be laser welded at the shoulder 238, the gasket 228 will melt due to the heat effect, and there is a possibility that good sealing cannot be maintained. In addition, the top surface 217a of the sealing body 217 and the upper surface 238a of the shoulder 238 are at different axial height positions, making it difficult to perform laser welding of the lead tab 290 and the lead tab 291 for connecting the positive electrode.

[0053] In contrast, Figure 7 That is, the cylindrical battery 10 of the embodiment Figure 6As shown in the corresponding enlarged cross-sectional view, in the cylindrical battery 10, the outer can 16 and the sealing body 17 are sealed and fixed by rewinding and riveting, and there is no gasket near the end portion of the cylindrical battery 10 on the axial upper side and radially outer side. Therefore, even if heat is applied near the end portion, it will not affect the sealing. Therefore, the lead tab 290 for negative electrode connection can be welded near the end portion. Furthermore, in the cylindrical battery 10, the axial position of the first flat portion 83 located at the front end of the rewinding portion 45 of the outer can 16 is approximately the same as the axial position of the second flat portion 85 located at the front end of the terminal cover 27. Therefore, it is easy to perform laser welding of a pair of lead tabs 290 for negative electrode connection and lead tabs 291 for positive electrode connection, which can greatly improve the productivity of the battery pack.

[0054] The inventors actually used 10 samples Figure 6 as well as Figure 7 The laser welding of the lead tab 290 and the lead tab 291 for positive electrode connection was performed, and the heat effect after welding was visually confirmed. In detail, the cylindrical battery 210 of the comparative example was subjected to a destruction inspection after welding, and the presence or absence of melting of the gasket 228 was visually confirmed. The results are shown in Table 2.

[0055] [Table 2]

[0056]

[0057] In the cylindrical battery 210 of the comparative example, the melting of the gasket was confirmed in all 10 samples, and it was confirmed that when the shoulder was laser welded, there might be problems with the sealing and insulation. On the other hand, in the cylindrical battery 10 of the embodiment, no problems were confirmed in the sealing in all samples. Therefore, if the cylindrical battery of the present disclosure is manufactured, both the lead tab 290 for connecting the negative electrode and the lead tab 291 for connecting the positive electrode can be laser welded to the axial upper side of the battery, which can greatly improve the productivity of the battery pack.

[0058] -Explanation of symbols-

[0059] 10, 110: cylindrical battery; 11: positive electrode; 12: negative electrode; 13: separator; 14: electrode body; 16, 116: outer can; 17: sealing body; 18: upper insulating plate; 19: lower insulating plate; 20: positive electrode lead; 21: negative electrode lead; 23, 123: gasket (first metal member); 27: terminal cover (second metal member); 28: liner (insulating member); 28 a: accommodating portion; 31, 131: rewinding portion of the gasket (second rewinding portion); 32: annular groove of the gasket; 39: annular groove of the liner; 42: ridge portion; 43: cylindrical portion; 45, 145: rewinding portion of the outer can (first rewinding portion); 68: bottom plate portion; 68a: bottom surface; 71: thin-walled portion; 72: safety valve; 80: rewinding fixing structure; 83: first plane portion; 85: second plane portion.

Claims

1. A cylindrical battery comprising: External cans; an electrode body housed in the outer can; and a sealing body for sealing the opening of the outer can, The outer can has: Bottom plate; a cylindrical portion connected to the bottom plate portion via an annular ridge portion located on the outer side in the radial direction and extending in the axial direction; and The first winding portion is connected to the end of the cylindrical portion on the side opposite to the edge portion in the axial direction. The sealing body includes a second winding portion, and the radially outer end portion is fixed to the first winding portion.

2. The cylindrical battery according to claim 1, wherein: The sealing body has: a first annular metal member having the second rewinding portion and a first annular groove, wherein the first annular groove is located at the radially inner end of the first metal member and opens toward the radially inner side; an annular insulating member having a second annular groove, the second annular groove being received in the first annular groove and opening toward the inner side in the radial direction; and The second metal member has an edge portion accommodated in the radially outer side of the second annular groove.

3. The cylindrical battery according to claim 2, wherein: The first winding portion has a first flat portion extending in a direction substantially perpendicular to the axial direction at a front end in the axial direction. The second metal member has a second flat surface portion extending in the orthogonal direction at the front end in the axial direction. The axial position of the first planar portion is substantially the same as the axial position of the second planar portion.

Images