Cylindrical battery

Abstract

A sealing body (17) includes: a lamination part (50) in which a terminal cap (27) and a terminal plate (40) are laminated on an annular flange part; and a circumferential extension chamber (55) that extends in the circumferential direction between the terminal cap (27) and the terminal plate (40). A coil spring (60) is housed in the circumferential extension chamber (55) in a contracted state in the circumferential direction. In the coil spring (60), the first end (60a) on the first side in the circumferential direction makes contact with only the terminal cap (27), and the second end (60b) on the second side in the circumferential direction makes contact with only the terminal plate (40). The lamination part (50) has an inclined contact part (70) in which two inclined surfaces (70a, 70b) inclined toward the electrode body side toward the second side in the circumferential direction come into contact with each other.

Description

Cylindrical battery

[0001] The present disclosure relates to cylindrical batteries.

[0002] A conventional cylindrical battery is described in Patent Document 1. This cylindrical battery includes an electrode assembly in which a positive electrode and a negative electrode are wound with a separator interposed therebetween, a bottomed cylindrical outer can that houses the electrode assembly, and a sealing body that is crimped and fixed to the opening of the outer can via a gasket. The positive electrode and the inner surface of the sealing body are electrically connected via a positive electrode lead, and the negative electrode and the inner bottom surface of the outer can are electrically connected via a negative electrode lead.

[0003] JP 2013-016328 A

[0004] If the sealing member and the outer can can be short-circuited when the battery abnormally heats up, the battery's energy will be reduced by the discharge caused by the short-circuit, making the battery highly safe. Therefore, an object of the present disclosure is to provide a cylindrical battery that can effectively short-circuit the sealing member and the outer can when the battery abnormally heats up.

[0005] In order to solve the above problems, the cylindrical battery according to the present disclosure comprises an electrode assembly in which a positive electrode and a negative electrode are wound with a separator interposed therebetween, a bottomed cylindrical outer can that houses the electrode assembly, and a sealing body that is crimped and fixed to the opening of the outer can via a gasket and includes a terminal cap and a terminal plate to which an electrode lead is joined, wherein the sealing body has a stacked portion in which the terminal cap and the terminal plate are stacked in the axial direction on an annular flange that forms the outer peripheral edge, and a circumferentially extending chamber that extends circumferentially between the terminal cap and the terminal plate, an elastic body is housed in the circumferentially extending chamber in a circumferentially contracted state, and the elastic body has a first end on a first circumferential side that contacts only the terminal cap and a second end on a second circumferential side that contacts only the terminal plate, and the stacked portion has an inclined abutment portion where the inclined surfaces of the terminal cap and the terminal plate, which are inclined toward the electrode assembly as they approach the second circumferential side, abut against each other.

[0006] The cylindrical battery according to the present disclosure can effectively short-circuit the sealing body and the outer can in the event of abnormal heat generation.

[0007] 1 is an axial cross-sectional view of a cylindrical battery according to an embodiment of the present disclosure; FIG. 2 is an enlarged cross-sectional view of the periphery of the stacking portion in FIG. 1; FIG. 3 is a plan view of the sealing body as seen from the terminal cap side, with the left half showing a state in which the terminal cap is present and the right half showing a state in which the terminal cap has been removed; FIG. 4 is a schematic cross-sectional view of the annular flange portion of the sealing body of an initial (before use) battery, cut in the axial direction along the circumferential direction passing through the central axis of the coil spring; FIG. 5 is a schematic cross-sectional view of the annular flange portion of the sealing body in a state in which the gasket is melted, cut in the axial cross section along the circumferential direction passing through the central axis of the coil spring; FIG. 6(a) is a diagram illustrating the configuration of a sealing body whose thickness increases when the terminal cap rotates clockwise relative to the terminal plate; and FIG. 6(b) is a diagram illustrating the configuration of a sealing body whose thickness increases when the terminal cap rotates counterclockwise relative to the terminal plate.

[0008] Hereinafter, an embodiment of a cylindrical battery according to the present disclosure will be described in detail with reference to the drawings. The cylindrical battery according to the present disclosure may be a primary battery or a secondary battery. It may also be a battery using an aqueous electrolyte or a battery using a non-aqueous electrolyte. Hereinafter, a non-aqueous electrolyte secondary battery (lithium ion battery) using a non-aqueous electrolyte will be exemplified as a cylindrical battery 10 according to one embodiment, but the cylindrical battery according to the present disclosure is not limited thereto.

[0009] When multiple embodiments and variations are included below, it is anticipated from the beginning that new embodiments can be constructed by appropriately combining their characteristic features. In the following embodiments, the same components are designated by the same reference numerals in the drawings, and redundant explanations are omitted. Furthermore, multiple drawings include schematic diagrams, and the dimensional ratios of the length, width, height, etc. of each component between different drawings do not necessarily match. In this specification, the side of the sealing body 17 in the axial direction (height direction) of the battery 10 is referred to as "upper," and the side of the bottom 68 of the outer can 16 in the axial direction is referred to as "lower." Furthermore, among the components described below, components not recited in the independent claims representing the highest concepts are optional components and not essential components.

[0010] Fig. 1 is an axial cross-sectional view of a cylindrical battery 10 according to one embodiment of the present disclosure. As shown in Fig. 1, the cylindrical battery 10 includes a wound electrode assembly 14, a non-aqueous electrolyte (not shown), an outer can 16 that houses the electrode assembly 14 and the non-aqueous electrolyte, and a sealing body 17. The electrode assembly 14 includes a positive electrode 11, a negative electrode 12, and two separators 13 interposed between the positive electrode 11 and the negative electrode 12, and has a wound structure in which the positive electrode 11 and the negative electrode 12 are wound with the two separators 13 interposed therebetween.

[0011] The non-aqueous electrolyte has ion conductivity (e.g., lithium ion conductivity). The non-aqueous electrolyte may be a liquid electrolyte (electrolytic solution) or a solid electrolyte. The liquid electrolyte (electrolytic solution) includes a non-aqueous solvent and an electrolyte salt dissolved in the non-aqueous solvent. Examples of the non-aqueous solvent include esters, ethers, nitriles, amides, and mixed solvents of two or more of these. Examples of the non-aqueous solvent include ethylene carbonate (EC), ethyl methyl carbonate (EMC), dimethyl carbonate (DMC), diethyl carbonate (DEC), and mixed solvents of these. The non-aqueous solvent may contain a halogen-substituted compound (e.g., fluoroethylene carbonate) in which at least a portion of the hydrogen atoms of these solvents are substituted with halogen atoms such as fluorine. The electrolyte salt may include, for example, LiPF ６ Lithium salts such as

[0012] Examples of the solid electrolyte include solid or gel polymer electrolytes and inorganic solid electrolytes. The polymer electrolyte includes, for example, a lithium salt and a matrix polymer, or a non-aqueous solvent, a lithium salt, and a matrix polymer. Examples of the matrix polymer include a polymer material that absorbs the non-aqueous solvent and gels. Examples of the polymer material include fluororesin, acrylic resin, and polyether resin. Examples of the inorganic solid electrolyte include materials known in all-solid-state lithium ion secondary batteries (e.g., oxide-based solid electrolytes, sulfide-based solid electrolytes, halide-based solid electrolytes, etc.).

[0013] Three positive electrode leads 20 are joined to the positive electrode 11, and a first negative electrode lead 21a and a second negative electrode lead 21b are joined to the negative electrode 12. The three positive electrode leads 20 are preferably joined at approximately equal intervals along the longitudinal direction of the strip-shaped positive electrode 11, since this shortens the longitudinal current path of the positive electrode and reduces the internal resistance of the cylindrical battery 10. The first negative electrode lead 21a is joined to the end of the negative electrode 12 at the start of winding, and the second negative electrode lead 21b is joined to the end of the negative electrode 12 at the end of winding. Only one positive electrode lead may be joined to the positive electrode, or two or four or more positive electrode leads may be joined. Furthermore, only one negative electrode lead may be joined to the negative electrode, or three or more negative electrode leads may be joined. The negative electrode 12 is formed to be slightly larger than the positive electrode 11 and longer in the longitudinal and width directions (short sides) than the positive electrode 11 to suppress lithium precipitation. The two separators 13 are formed to have dimensions at least one size larger than the positive electrode 11 and are arranged to sandwich the positive electrode 11 therebetween.

[0014] The positive electrode 11 has a positive electrode current collector and a positive electrode mixture layer formed on both sides of the positive electrode current collector. The positive electrode current collector can be a metal foil, such as aluminum or an aluminum alloy, that is stable within the potential range of the positive electrode 11, or a film with such a metal disposed on the surface layer. The positive electrode mixture layer contains a positive electrode active material, a conductive agent, and a binder. The positive electrode 11 can be produced, for example, by applying a positive electrode mixture slurry containing a positive electrode active material, a conductive agent, a binder, etc., onto the positive electrode current collector, drying the coating, and then compressing it to form a positive electrode mixture layer on both sides of the positive electrode current collector.

[0015] The positive electrode active material is mainly composed of a lithium-containing metal composite oxide. Examples of metal elements contained in the lithium-containing metal composite oxide include Ni, Co, Mn, Al, B, Mg, Ti, V, Cr, Fe, Cu, Zn, Ga, Sr, Zr, Nb, In, Sn, Ta, and W. An example of a preferred lithium-containing metal composite oxide is a composite oxide containing at least one of Ni, Co, Mn, and Al.

[0016] Examples of conductive agents contained in the positive electrode mixture layer include carbon materials such as carbon black, acetylene black, ketjen black, and graphite. Examples of binders contained in the positive electrode mixture layer include fluororesins such as polytetrafluoroethylene (PTFE) and polyvinylidene fluoride (PVdF), polyacrylonitrile (PAN), polyimide resins, acrylic resins, and polyolefin resins. These resins may be used in combination with cellulose derivatives such as carboxymethyl cellulose (CMC) or its salts, polyethylene oxide (PEO), and the like.

[0017] The negative electrode 12 has a negative electrode current collector and a negative electrode mixture layer formed on both sides of the negative electrode current collector. The negative electrode current collector can be a metal foil, such as copper or a copper alloy, that is stable within the potential range of the negative electrode 12, or a film with such a metal disposed on the surface layer. The negative electrode mixture layer contains a negative electrode active material and a binder. The negative electrode 12 can be produced, for example, by applying a negative electrode mixture slurry containing the negative electrode active material and the binder onto the negative electrode current collector, drying the coating, and then compressing it to form a negative electrode mixture layer on both sides of the current collector.

[0018] The negative electrode active material generally uses a carbon material that reversibly absorbs and releases lithium ions. Preferred carbon materials are graphites such as natural graphite, such as flake graphite, lump graphite, and amorphous graphite, and artificial graphite, such as lump artificial graphite and graphitized mesophase carbon microbeads. The negative electrode mixture layer may contain a silicon (Si) material as the negative electrode active material. In addition, the negative electrode active material may be a metal other than Si that alloys with lithium, an alloy containing such a metal, or a compound containing such a metal.

[0019] As in the case of the positive electrode 11, fluororesin, PAN, polyimide resin, acrylic resin, polyolefin resin, or the like may be used as the binder contained in the negative electrode mixture layer, but styrene-butadiene rubber (SBR) or a modified product thereof is preferably used. In addition to SBR or the like, the negative electrode mixture layer may also contain, for example, CMC or a salt thereof, polyacrylic acid (PAA) or a salt thereof, polyvinyl alcohol, or the like.

[0020] The separator 13 is a porous sheet having ion permeability and insulating properties. Specific examples of the porous sheet include a microporous thin film, a woven fabric, and a nonwoven fabric. Preferred materials for the separator 13 include polyolefin resins such as polyethylene and polypropylene, and cellulose. The separator 13 may have either a single-layer structure or a laminated structure. A heat-resistant layer or the like may be formed on the surface of the separator 13. The negative electrode 12 may form the winding start end of the electrode assembly 14, but typically the separator 13 extends beyond the winding start end of the negative electrode 12, and the winding start end of the separator 13 becomes the winding start end of the electrode assembly 14.

[0021] The cylindrical battery 10 includes an insulating plate 18 disposed above the electrode assembly 14. A positive electrode lead 20 attached to the positive electrode 11 passes through a through-hole in the insulating plate 18 and extends toward the sealing body 17. The sealing body 17 includes a terminal plate 40 and a terminal cap 27. The terminal plate 40 is an annular metal plate member with a through-hole 40a in its radial center. The terminal cap 27 is a metal plate member without a through-hole, and closes the opening of the outer can 16. The sealing body 17 further includes a metal plate 41. The metal plate 41 is an annular metal member with a through-hole 41a.

[0022] Each positive electrode lead 20 is bent from the positive electrode 11 through the through hole 40a of the terminal plate 40 so as to fit along the upper surface of the terminal plate 40. The tip of each positive electrode lead 20 is sandwiched between the upper surface of the terminal plate 40 and the lower surface of the metal plate 41. Each positive electrode lead 20 is bonded to the upper surface of the terminal plate 40. The terminal plate 40 and the metal plate 41 are also bonded, and each positive electrode lead 20 and the metal plate 41 are also bonded. These bonds can be achieved, for example, by laser welding the tip of the positive electrode lead 20 sandwiched between the terminal plate 40 and the metal plate 41 from the side opposite the terminal plate 40 in the thickness direction of the metal plate 41. Note that the metal plate 41 does not necessarily have to be present. Alternatively, the positive electrode lead 20 may be bonded to the lower surface of the terminal plate 40.

[0023] The sealing body 17 has an annular flange portion 33 constituting the outer peripheral edge portion, a stacked portion 50 in which the terminal cap 27 and the terminal plate 40 are stacked, and a circumferentially extending chamber 55 extending circumferentially between the terminal cap 27 and the terminal plate 40. The terminal cap 27 and the terminal plate 40 abut in the stacked portion 50 so as to be relatively movable. The annular upper surface of the terminal plate 40 has an annular recess 45 radially inward from the stacked portion 50. Because the upper surface of the terminal plate 40 has the recess 45 recessed downward, a space is provided between the terminal cap 27 and the recess 45 of the terminal plate 40. Each positive electrode lead 20 is joined to the terminal plate 40 within the recess 45.

[0024] The cylindrical battery 10 has a ring-shaped insulating plate 19 disposed below the electrode body 14. A first negative electrode lead 21a joined to the end of the negative electrode 12 at the winding start side passes through a through-hole 19a in the insulating plate 19 and is then bent radially inward. A second negative electrode lead 21b joined to the end of the negative electrode 12 at the winding end side passes outside the insulating plate 19 and is then bent radially inward to overlap the first negative electrode lead 21a. For example, the overlapping portion of the first negative electrode lead 21a and the second negative electrode lead 21b is resistance-welded using a welding rod inserted into the hollow portion 14a of the electrode body 14 and joined to the inner surface of the bottom 68 of the outer can 16.

[0025] The outer can 16 has a cylindrical portion 39 and a bottom 68. The cylindrical portion 39 includes an annular grooved portion 35 and an annular shoulder portion 29. The grooved portion 35 is formed by spinning a portion of the cylindrical portion 39 to recess it radially inward. The sealing body 17 is placed on the grooved portion 35 and is fixed to the opening of the outer can 16 by crimping via a resin gasket 28. The shoulder portion 29 is formed when the upper end of the cylindrical portion 39 is bent radially inward and crimped to the flange portion 33 of the sealing body 17, and extends radially inward at the upper end of the cylindrical portion 39.

[0026] The gap between the outer can 16 and the sealing body 17 is sealed with an annular gasket 28, thereby sealing the internal space of the battery 10. The gasket 28 is sandwiched between the outer can 16 and the sealing body 17, and insulates the sealing body 17 from the outer can 16. The gasket 28 serves as a sealing material to maintain airtightness inside the battery and as an insulating material to insulate the outer can 16 and the sealing body 17.

[0027] In the cylindrical battery 10, the terminal cap 27 electrically connected to the positive electrode lead 20 serves as the positive electrode terminal, and the outer can 16 electrically connected to the negative electrode leads 21a, 21b serves as the negative electrode terminal. The cylindrical battery 10 has a thin, easily breakable portion 68a on the bottom 68 of the outer can 16. The easily breakable portion 68a is formed, for example, by stamping a circle or C-shape on the bottom 68. If the easily breakable portion 68a is provided on the bottom 68, when the cylindrical battery 10 abnormally heats up, the easily breakable portion 68a breaks, allowing high-temperature gas inside the battery to be discharged to the outside, thereby improving the safety of the battery 10. The thin, easily breakable portion may also be provided on the terminal cap.

[0028] FIG. 2 is an enlarged cross-sectional view of the laminated portion 50 and its surroundings in FIG. 1 . FIG. 3 is a plan view of the sealing body 17 from the terminal cap 27 side, with the left half showing the state with the terminal cap 27 present and the right half showing the state with the terminal cap 27 removed. As shown in FIGS. 2 and 3 , the terminal cap 27 has a first recess 27a extending circumferentially on its lower surface, and the terminal plate 40 has a second recess 40b extending circumferentially on its upper surface. The first recess 27a and the second recess 40b are axially opposed to each other to define a circumferentially extending chamber 55 extending circumferentially between the terminal cap 27 and the terminal plate 40. The circumferentially extending chamber 55 houses a coil spring 60 that is circumferentially compressed when the battery 10 is not generating abnormal heat. The coil spring 60 is an example of an elastic body.

[0029] Figure 4 is a schematic cross-sectional view of the annular flange portion 33 of the initial (before use) sealing body 17, cut axially along the circumferential direction passing through the central axis of the coil spring 60. The dotted line in Figure 4 coincides with the circumferential direction of the battery 10. In the example shown in Figure 4, the battery 10 includes two coil springs 60 spaced equally apart in the circumferential direction, but the battery may include one or three or more coil springs. A first end 60a on a first circumferential side of the coil spring 60 abuts only against the terminal cap 27, and a second end 60b on a second circumferential side of the coil spring 60 abuts only against the terminal plate 40.

[0030] At circumferential position S1 where coil spring 60 abuts against terminal cap 27, the thickness of terminal cap 27 is greater than the thickness of terminal plate 40, and at circumferential position S2 where coil spring 60 abuts against terminal plate 40, the thickness of terminal plate 40 is greater than the thickness of terminal cap 27. In the initial (before use) battery 10, stacked portion 50 has a horizontal abutment portion 65 where horizontal surfaces 65a, 65b of terminal cap 27 and terminal plate 40, which extend approximately parallel to the radial direction (orthogonal to the axial direction), abut against each other, and an inclined abutment portion 70 where inclined surfaces 70a, 70b of terminal cap 27 and terminal plate 40, which incline toward electrode body 14 (axially downward) toward the second circumferential side, abut against each other. The two inclined surfaces 70a, 70b are flat surfaces.

[0031] The laminated portion 50 has a stopper 75 at a position adjacent to the end of the inclined abutment portion 70 on the second circumferential side, which limits the relative rotation of the terminal cap 27 in the second circumferential direction with respect to the terminal board 40. The stopper 75 is formed by a protruding portion 80 that protrudes upward from a position adjacent to the lower end of the inclined surface 70b of the terminal board 40 that constitutes the inclined abutment portion 70. On the other hand, the relative rotation of the terminal cap 27 in the first circumferential direction with respect to the terminal board 40 is permitted.

[0032] When assembling the sealing body 17, with the coil spring 60 housed in the circumferentially extending chamber 55, the terminal cap 27 is rotated relative to the terminal plate 40 toward the second circumferential side until the lower end of the inclined surface 70a of the terminal cap 27 contacts the protrusion 80. This causes the coil spring 60 to be compressed in the circumferential direction. While maintaining this state, the upper end of the tubular portion 39 is bent radially inward to be crimped. This crimping clamps the laminated portion 50 between the shoulder portion 29 and the grooved portion 35 via the gasket 28, applies an axial load to the laminated portion 50, and the horizontal surfaces 65a, 65b of the terminal cap 27 and the terminal plate 40 abut against each other in the axial direction.

[0033] When the battery 10 generates abnormal heat and the resin gasket 28 melts, the axial load applied to the laminated portion 50 disappears, and the restoring force of the coil spring 60 causes the terminal cap 27 to rotate relative to the terminal plate 40 toward the first circumferential side. As shown in FIG. 5 , the inclined surface 70 a of the terminal cap 27 moves toward the first circumferential side relative to the inclined surface 70 b of the terminal plate 40, increasing the thickness of the sealing body 17. When the coil spring 60 is released from circumferential compression, the thickness of the sealing body 17 exceeds the axial length t (see FIG. 2 ) between the lower surface of the shoulder portion 29 and the upper surface of the grooved portion 35. Thus, when the battery 10 generates abnormal heat and the resin gasket 28 melts, the sealing body 17 effectively contacts the outer can 16, effectively short-circuiting the positive electrode 11 to the negative electrode 12. Therefore, when the battery 10 generates abnormal heat, the energy of the battery 10 is reduced by discharge associated with the short circuit, ensuring high safety of the battery 10.

[0034] The inclined abutment portion 70 may be provided at only one location on the stacked portion 50. However, in order to smoothly increase the thickness of the sealing body 17 when the battery 10 generates abnormal heat, it is preferable that the inclined abutment portion 70 be provided at multiple locations that are different from each other in the circumferential direction, and it is more preferable that the multiple inclined abutment portions 70 are substantially identical and are provided at substantially equal intervals in the circumferential direction.

[0035] The inclined abutment portion 70 may be provided radially over the entire area of ​​the stacked portion 50, or may be provided radially over only a portion of the stacked portion 50. In order to smoothly increase the thickness of the sealing body 17 when abnormal heat generation occurs in the battery 10, the inclined abutment portion 70 is preferably provided radially over the entire area of ​​the stacked portion 50.

[0036] As shown in Figure 4, in the initial (before use) battery 10, it is preferable that there be an axial gap between the terminal cap 27 and the terminal plate 40 at circumferential positions S1 and S2 (see Figure 4). In this case, the static frictional force and dynamic frictional force generated between the terminal cap 27 and the terminal plate 40 are small, so that when the axial load applied to the stacked portion 50 disappears, the terminal cap 27 can smoothly rotate relative to the terminal plate 40.

[0037] The present disclosure is not limited to the above-described embodiment and its variations, and various improvements and modifications are possible within the scope of the claims of the present application and their equivalents. Although the laminated portion 50 has been described as having a stopper 75, the laminated portion does not need to have a stopper. Furthermore, the positive electrode lead 20 is joined to the terminal plate 40 of the sealing body 17, and the negative electrode leads 21a, 21b are joined to the outer can 16. However, the negative electrode lead may be joined to the terminal plate of the sealing body, and the positive electrode lead may be joined to the outer can.

[0038] In the above embodiment, the elastic body is the coil spring 60. However, the elastic body may be any elastic member that is stretchable in the circumferential direction and is made of a material that has better heat resistance than the gasket 28. The elastic body may be made of, for example, a metal plate member that is folded in a zigzag sawtooth pattern and has elasticity that extends in the circumferential direction.

[0039] The present disclosure may be configured such that the thickness of the sealing body increases when the terminal cap rotates clockwise relative to the terminal plate, or may be configured such that the thickness of the sealing body increases when the terminal cap rotates counterclockwise relative to the terminal plate. In either case, the inclination direction of the inclined abutment portion is determined so that when the terminal cap rotates relative to the terminal plate, the terminal cap moves upward and the terminal plate moves downward. The rotation direction of the terminal cap is assigned either clockwise or counterclockwise based on the rotation direction of the sealing body as viewed from the terminal cap side. For example, in FIG. 6 , if the direction from right to left on the page is defined as the clockwise direction, as shown in FIG. 6( a), to increase the thickness of the sealing body when the terminal cap rotates clockwise relative to the terminal plate, the left end of the coil spring may contact only the terminal cap and the right end of the coil spring may contact only the terminal plate. In this case, if a stopper is provided, the stopper may be provided on the right side (second circumferential side) of the inclined abutment portion.

[0040] 6(b), if the thickness of the sealing body is to be increased when the terminal cap rotates counterclockwise relative to the terminal plate, the right end of the coil spring should contact only the terminal cap, and the left end of the coil spring should contact only the terminal plate. In this case, if a stopper is provided, the stopper should be provided on the left side (second circumferential side) of the inclined abutment portion. From the above, it can be seen that in both the cases of FIG. 6(a) and FIG. 6(b), the stopper should be provided on the second side of the inclined abutment portion.

[0041] The cylindrical battery of the present disclosure may also have the following configuration: Configuration 1: A cylindrical battery comprising: an electrode assembly in which a positive electrode and a negative electrode are wound with a separator interposed therebetween; a bottomed, tubular outer can that houses the electrode assembly; and a sealing body that is fixed to an opening of the outer can by crimping via a gasket and includes a terminal cap and a terminal plate to which an electrode lead is joined, wherein the sealing body has an annular flange that forms an outer peripheral edge, and a stacking portion in which the terminal cap and the terminal plate are stacked in the axial direction, and a circumferentially extending chamber that extends circumferentially between the terminal cap and the terminal plate, an elastic body is housed in the circumferentially extending chamber while being compressed in the circumferential direction, a first end of the elastic body on a first circumferential side contacts only the terminal cap and a second end of the elastic body on a second circumferential side contacts only the terminal plate, and the stacking portion has an inclined abutment portion where inclined surfaces of the terminal cap and the terminal plate abut against each other, the inclined surfaces being inclined toward the electrode assembly as they approach the second circumferential side. Configuration 2: The cylindrical battery according to Configuration 1, wherein the stacking portion has a stopper adjacent to an end of the inclined abutment portion on the second side in the circumferential direction, the stopper limiting relative rotation of the terminal cap toward the second side in the circumferential direction with respect to the terminal plate.Configuration 3: The cylindrical battery according to Configuration 1 or 2, wherein the inclined abutment portion is provided at a plurality of locations that are different from one another in the circumferential direction.Configuration 4: The cylindrical battery according to Configuration 3, wherein the plurality of inclined abutment portions are substantially identical and are provided at substantially equal intervals in the circumferential direction.Configuration 5: The cylindrical battery according to any one of Configurations 1 to 4, wherein the elastic body is a coil spring.Configuration 6: The cylindrical battery according to any one of Configurations 1 to 5, wherein a thin, easily breakable portion is provided at the bottom of the outer can.

[0042] REFERENCE SIGNS LIST 10 battery, 11 positive electrode, 12 negative electrode, 13 separator, 14 electrode body, 14a hollow portion, 16 outer can, 17 sealing body, 18, 19 insulating plate, 19a through hole, 20 positive electrode lead, 21a first negative electrode lead, 21b second negative electrode lead, 27 terminal cap, 28 gasket, 29 shoulder portion, 33 flange portion, 35 grooved portion, 39 cylindrical portion, 40 terminal plate, 40a through hole, 41 metal plate, 41a through hole, 50 stacked portion, 55 circumferentially extending chamber, 60 coil spring, 60a first end portion, 60b second end portion, 65 horizontal abutment portion, 65a, 65b horizontal surface, 68 bottom portion, 68a: Easy-to-break portion; 70: Inclined abutment portion; 70a, 70b: Inclined surface; 75: Stopper; 80: Protrusion.

Claims

1. A cylindrical battery comprising: an electrode assembly in which a positive electrode and a negative electrode are wound with a separator interposed therebetween; a bottomed, cylindrical outer can that contains the electrode assembly; and a sealing body that is crimped to an opening of the outer can via a gasket and includes a terminal cap and a terminal plate to which an electrode lead is joined, wherein the sealing body has an annular flange that constitutes an outer peripheral edge, a laminated portion in which the terminal cap and the terminal plate are laminated in the axial direction, and a circumferentially extending chamber that extends in the circumferential direction between the terminal cap and the terminal plate, an elastic body is contained in the circumferentially extending chamber while being compressed in the circumferential direction, and a first end portion of the elastic body on a first circumferential side contacts only the terminal cap and a second end portion of the elastic body on a second circumferential side contacts only the terminal plate, and the laminated portion has an inclined abutment portion where inclined surfaces of the terminal cap and the terminal plate that incline toward the electrode assembly as they approach the second circumferential side abut against each other.

2. The cylindrical battery according to claim 1, wherein the stacking portion has a stopper located adjacent to the end of the inclined abutment portion on the second circumferential side, which limits relative rotation of the terminal cap toward the second circumferential side with respect to the terminal plate.

3. A cylindrical battery as set forth in claim 1 or 2, wherein the inclined contact portions are provided at a plurality of locations that are mutually different in position in the circumferential direction.

4. The cylindrical battery according to claim 3, wherein the plurality of inclined contact portions are substantially identical and are provided at substantially equal intervals in the circumferential direction.

5. The cylindrical battery according to claim 1 or 2, wherein the elastic body is a coil spring.

6. The cylindrical battery according to claim 1 or 2, wherein a thin, easily breakable portion is provided at the bottom of the outer can.

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