Cylindrical battery

Abstract

A battery (10) comprises: an electrode body; an exterior can (20) that houses the electrode body; and a sealing body that closes an opening of the exterior can (20) via a gasket (24). The sealing body has: a sealing plate (22); a terminal plate (21) to which a positive electrode lead extending from the electrode body is joined and to which the sealing plate (22) is joined on the center side in the radial direction; and an annular insulating plate (23) having insulating properties and including a hold part held between the sealing plate (22) and the terminal plate (21). The sealing plate (22) includes a protrusion (70) protruding toward the electrode body side in the axial direction. At least a portion of the protrusion (70) is disposed at a location overlapping the terminal plate (21) in the axial direction.

Description

Cylindrical battery

[0001] The present disclosure relates to a cylindrical battery.

[0002] Conventionally, there is a cylindrical battery described in Patent Document 1. This cylindrical battery includes an electrode body, a bottomed cylindrical outer can that houses the electrode body, and a sealing body that closes the opening of the outer can via a gasket. The cylindrical portion of the outer can has a grooved portion and an annular shoulder portion. The grooved portion is formed by recessing a part of the cylindrical portion inward in the radial direction. The shoulder portion is formed when the end portion on the opening side of the cylindrical portion is bent inward and caulked to the peripheral edge portion of the sealing body, and extends inward in the radial direction.

[0003] Japanese Patent Laid-Open No. 9-320562

[0004] The sealing body of the cylindrical battery includes a sealing plate, a terminal plate to which an electrode lead extending from the electrode body is joined and the sealing plate is joined to the central side in the radial direction, and an annular insulating plate that includes a sandwiched portion sandwiched between the sealing plate and the terminal plate and has insulating properties. When the internal pressure of the battery rises above a predetermined value, the joint between the sealing plate and the terminal plate breaks and the current path is interrupted, ensuring safety.

[0005] In recent years, assuming various worst-case scenarios, it has been required to further improve the safety performance as described above. For example, due to aging deterioration or manufacturing variations, the sealing plate may be deformed so as to be displaced outward in the axial direction, and along with this deformation, the terminal plate may be shaped such that it bulges toward the sealing plate side in the axial direction. As a result, even if the breakage of the joint between the sealing plate and the terminal plate is near the assumed breaking pressure, it may be difficult to occur. Therefore, an object of the present disclosure is to provide a cylindrical battery in which the current interruption mechanism can be appropriately operated easily even when the sealing plate is displaced outward in the axial direction.

[0006] To solve the above problems, the cylindrical battery according to the present disclosure comprises an electrode body, an outer casing for housing the electrode body, and a sealing body that closes the opening of the outer casing via a gasket, wherein the sealing body includes a sealing plate, a terminal plate to which electrode leads extending from the electrode body are joined and to which the sealing plate is joined on the radially central side, and an annular insulating plate that includes a clamping portion sandwiched between the sealing plate and the terminal plate and is insulating, wherein the sealing plate includes a projection that protrudes toward the electrode body in the axial direction, and at least a part of the projection is positioned to overlap with the terminal plate in the axial direction.

[0007] According to the cylindrical battery described herein, the current interruption mechanism can be easily operated properly even if the sealing plate is displaced axially outward.

[0008] This is an axial cross-sectional view of a cylindrical battery according to one embodiment of the present disclosure. This is an enlarged cross-sectional view of the area around the shoulder portion in Figure 1. This is an enlarged cross-sectional view corresponding to Figure 2 of a cylindrical battery of a reference example. This is a diagram illustrating the normal operation of the current interruption mechanism of the cylindrical battery of a reference example. This is a diagram illustrating potential problems that may occur in the cylindrical battery of a reference example. This is a diagram illustrating the normal operation of the current interruption mechanism of the cylindrical battery of the above embodiment. This is a diagram illustrating why the above problems are less likely to occur in the cylindrical battery of the above embodiment. This is an enlarged cross-sectional view corresponding to Figure 2 of a cylindrical battery of a first modified example. This is an enlarged cross-sectional view corresponding to Figure 2 of a cylindrical battery of a second modified example.

[0009] Hereinafter, embodiments of the cylindrical battery according to this disclosure will be described in detail with reference to the drawings. The cylindrical battery of this 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. In the following, a lithium-ion secondary battery is given as an example of a cylindrical battery 10 in one embodiment, but the cylindrical battery of this disclosure is not limited to this.

[0010] It is intended from the outset that new embodiments can be constructed by appropriately combining the characteristic features of the embodiments and modifications described below. In the following embodiments, the same reference numerals are used for the same components in the drawings, and redundant explanations are omitted. In addition, multiple drawings include schematic diagrams, and the dimensional ratios such as length, width, and height of each component do not necessarily match between different drawings. In this specification, the axial (height direction) sealing body 19 side of the cylindrical battery 10 is referred to as "top," and the axial bottom 20A side of the outer casing 20 is referred to as "bottom." Among the components described below, components that are not described in the independent claim indicating the highest-level concept are optional components and are not essential components.

[0011] Figure 1 is an axial cross-sectional view of a cylindrical battery 10 according to one embodiment of the present disclosure. As shown in Figure 1, the cylindrical battery (hereinafter simply referred to as "battery") 10 comprises an electrode body 14, a non-aqueous electrolyte, a bottomed cylindrical outer casing 20 housing the electrode body 14 and the non-aqueous electrolyte, and a sealing body 19 that closes the opening of the outer casing 20 via an annular gasket 24. In the example shown in Figure 1, the outer casing 20 has a bottomed cylindrical shape, but the outer casing may have openings at both the upper and lower ends, and each opening may be closed by one or more members.

[0012] The electrode body 14 includes a long positive electrode 11, a long negative electrode 12, and two long 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 around the separators 13. The negative electrode 12 is formed to be slightly larger in dimensions than the positive electrode 11 in order to prevent lithium deposition. The negative electrode 12 is formed to be longer than the positive electrode 11 in the winding direction and in the axial direction. The two separators 13 are formed to be slightly larger in dimensions than the positive electrode 11 and are arranged to sandwich the positive electrode 11. The separators 13 protrude above and below the positive electrode 11 and the negative electrode 12.

[0013] Non-aqueous electrolytes are ionic conductive (e.g., lithium ion conductive). Non-aqueous electrolytes may be liquid electrolytes (electrolytes) or solid electrolytes. Liquid electrolytes (electrolytes) contain a non-aqueous solvent and an electrolyte salt dissolved in the non-aqueous solvent. Examples of non-aqueous solvents include esters, ethers, nitriles, amides, and mixtures of two or more of these. Examples of non-aqueous solvents include ethylene carbonate (EC), ethyl methyl carbonate (EMC), dimethyl carbonate (DMC), diethyl carbonate (DEC), and mixtures thereof. Non-aqueous solvents may contain halogen-substituted compounds (e.g., fluoroethylene carbonate) in which at least some of the hydrogen atoms in these solvents are replaced with halogen atoms such as fluorine. Examples of electrolyte salts include LiPF4. ６ Lithium salts such as these are used.

[0014] As solid electrolytes, for example, solid or gel-like polymer electrolytes, inorganic solid electrolytes, etc., are used. Polymer electrolytes include, for example, a lithium salt and a matrix polymer, or a non-aqueous solvent, a lithium salt and a matrix polymer. As matrix polymers, for example, polymer materials that absorb non-aqueous solvents and gel are used. As polymer materials, for example, fluororesins, acrylic resins, polyether resins, etc., are used. As inorganic solid electrolytes, for example, materials known for all-solid-state lithium-ion secondary batteries, etc. (for example, oxide-based solid electrolytes, sulfide-based solid electrolytes, halide-based solid electrolytes, etc.) are used.

[0015] The positive electrode 11 has a positive electrode core and a positive electrode mixture layer formed on both sides of the positive electrode core. The positive electrode core can be made of a metal foil that is stable within the potential range of the positive electrode 11, such as aluminum or an aluminum alloy, or a film with the metal arranged on its surface. The positive electrode mixture layer contains a positive electrode active material, a conductive agent, and a binder. The positive electrode is manufactured, for example, by applying a positive electrode mixture slurry containing a positive electrode active material, a conductive agent, and a binder onto the positive electrode core, drying the coating, and then compressing it to form the positive electrode mixture layer on both sides of the positive electrode core.

[0016] 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. A preferred example of a lithium-containing metal composite oxide is a composite oxide containing at least one of Ni, Co, Mn, and Al.

[0017] Examples of conductive agents included in the positive electrode mixture layer include carbon black such as acetylene black and Ketjen black, and carbon materials such as graphite. Examples of binders included 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 carboxymethylcellulose (CMC) or its salts, polyethylene oxide (PEO), etc.

[0018] The negative electrode 12 comprises a negative electrode core and negative electrode mixture layers formed on both sides of the negative electrode core. The negative electrode core can be made of a metal foil that is stable within the potential range of the negative electrode 12, such as copper or a copper alloy, or a film with the metal arranged on its surface. The negative electrode mixture layers contain a negative electrode active material and a binder. The negative electrode 12 is manufactured, for example, by applying a negative electrode mixture slurry containing the negative electrode active material and binder onto the negative electrode core, drying the coating, and then compressing it to form the negative electrode mixture layers on both sides of the negative electrode core.

[0019] Generally, carbon materials that reversibly intercept and release lithium ions are used as the negative electrode active material. Preferred carbon materials are graphite such as natural graphite such as flake graphite, lump graphite, and clay graphite, and artificial graphite such as lump graphite and graphitized mesophase carbon microbeads. The negative electrode mixture layer may contain silicon (Si) material as the negative electrode active material. In addition, metals that alloy with lithium other than Si, alloys containing such metals, compounds containing such metals, etc., may be used as the negative electrode active material.

[0020] The binder included in the negative electrode mixture layer may be fluororesin, PAN, polyimide resin, acrylic resin, polyolefin resin, etc., as in the case of the positive electrode 11, but preferably styrene-butadiene rubber (SBR) or a modified version thereof is used. In addition to SBR, the negative electrode mixture layer may also contain, for example, CMC or a salt thereof, polyacrylic acid (PAA) or a salt thereof, polyvinyl alcohol, etc.

[0021] A porous sheet having ion permeability and insulating properties is used for the separator 13. Specific examples of porous sheets include microporous thin films, woven fabrics, and nonwoven fabrics. The material of the separator 13 is preferably polyethylene, polyolefin resins such as polypropylene, or 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.

[0022] An upper insulating plate 15 is positioned above the electrode body 14, and a lower insulating plate 16 is positioned below the electrode body 14. In the example shown in Figure 1, the positive electrode lead 17 attached to the positive electrode 11 extends through a through-hole in the upper insulating plate 15 towards the sealing body 19 and is connected to the lower surface of the sealing body 19 by welding or the like. On the other hand, the negative electrode lead 18 attached to the negative electrode 12 extends outside the lower insulating plate 16 towards the bottom 20A of the outer can 20 and is connected to the inner surface of the bottom 20A by welding or the like. The sealing body 19 to which the positive electrode lead 17 is connected becomes the positive electrode terminal, and the outer can 20 to which the negative electrode lead 18 is connected becomes the negative electrode terminal. The positive electrode lead 17 is an example of an electrode lead that is electrically connected to the sealing body 19.

[0023] The case described above has been one in which the battery 10 has a single negative electrode lead 18 extending from the radial end of the electrode body 14 toward the bottom 20A. However, the battery may also have a plurality of negative electrode leads that electrically connect the negative electrode of the electrode body to the bottom of the outer casing, and one end of each of the plurality of negative electrode leads may be joined to the negative electrode at intervals in the longitudinal direction of the negative electrode. Alternatively, one axial end of the electrode body may be a strip-shaped negative electrode core exposed portion, and this negative electrode core exposed portion may be joined to the bottom of the outer casing via a negative electrode current collector plate for electrical connection.

[0024] Furthermore, at least a portion of the outermost surface of the electrode body may be composed of an exposed negative electrode core, and this exposed negative electrode core may be in contact with the inner surface of the outer can. In this case, the end of the negative electrode of the electrode body on the winding start side may be electrically connected to the bottom of the outer can via a negative electrode lead passing through a through hole in the lower insulating plate. This effectively shortens the current path on the negative electrode side and effectively reduces electrical resistance. Even if the exposed negative electrode core is not in contact with the inner surface of the outer can, the end of the negative electrode of the electrode body on the winding start side may be electrically connected to the bottom of the outer can via a negative electrode lead passing through a through hole in the lower insulating plate.

[0025] A gasket 24 is provided between the outer casing 20 and the sealing body 19 to ensure airtightness inside the battery and insulation between the outer casing 20 and the sealing body 19. The outer casing 20 has a cylindrical portion 20B and a bottom portion 20A, and the cylindrical portion 20B includes an annular grooved portion 28 and an annular shoulder portion 29. The grooved portion 28 is formed by spinning a part of the cylindrical portion 20B to create a recess radially inward. On the other hand, the shoulder portion 29 is formed when the upper end of the cylindrical portion 20B is bent radially inward and crimped to the peripheral edge portion 31 of the sealing body 19, and extends radially inward. The sealing body 19 is fixed to the outer casing 20 by being sandwiched between the shoulder portion 29 and the grooved portion 28 via the gasket 24 through crimping. More specifically, the outer peripheral edge of the sealing plate 22 of the sealing body 19 (the annular portion outside the thickened portion 35, which will be described later) is sandwiched between the shoulder portion 29 and the grooved portion 28 via a gasket 24 and fixed to the outer can 20.

[0026] The sealing body 19 has a structure in which a metal terminal plate 21, an annular insulating plate 23, and a metal sealing plate 22 are stacked in order from the electrode body 14 side. The sealing plate 22 constitutes a rupture plate (valve body) and is positioned opposite the terminal plate 21 with the insulating plate 23 in between. The insulating plate 23 has an opening 23A formed in the radial center and a ventilation hole 23B provided in the part that overlaps with the ventilation hole 21C of the terminal plate 21. The sealing plate 22 has a valve portion 22A on the radial center side that ruptures as the internal pressure of the battery rises. The terminal plate 21 has an annular portion 21A and a central portion 21B that is connected to the radially inward end of the annular portion 21A and is located in the radial center. The central portion 21B has a disc shape and is thinner than the annular portion 21A.

[0027] The valve portion 22A is joined to the central portion 21B of the terminal plate 21 by welding or the like through an opening 23A in the insulating plate 23. The valve portion 22A includes a projection 33 located in the radial center and projecting downward, and a thin-walled portion 34 located radially outside the projection 33. The thickness of the thin-walled portion 34 decreases as it extends radially outward. Because the thickness of the thin-walled portion 34 decreases as it extends radially outward, an annular space 39 is provided below the thin-walled portion 34. The insulating plate 23 is positioned radially outside the projection 33 so as to surround the projection 33 around its entire circumference. The majority of the insulating plate 23 is located between the sealing plate 22 and the terminal plate 21.

[0028] The sealing plate 22 holds the insulating plate 23, and the insulating plate 23 holds the terminal plate 21. Specifically, the sealing plate 22 includes an annular thickened portion 35 connected to the radially outward end of the thinned portion 34, and the thickened portion 35 has an annular projection 37 that protrudes downward. The outer circumferential surface of the insulating plate 23 is fitted and fixed to the inner circumferential surface of the annular projection 37. The insulating plate 23 also has an annular projection 38 that protrudes downward on the outer circumferential side, and the inner circumferential surface of the annular projection 38 is fitted and fixed to the outer circumferential surface of the terminal plate 21. The insulating plate 23 includes a clamping portion 43 that is sandwiched radially between the annular projection 37 and the terminal plate 21. The ventilation hole 21C is provided in the annular portion 21A. The positive lead 17 is joined to the lower surface of the annular portion 21A. The terminal board 21 to which the positive lead 17 is connected and the sealing plate 22 are electrically connected, thereby forming a current path from the electrode body 14 to the sealing plate 22.

[0029] Figure 2 is an enlarged cross-sectional view of the area around the shoulder portion 29 in Figure 1. As shown in Figure 2, the insulating plate 23 has a recess in its standalone state, and accordingly, the battery 10 has an annular recess 65 on the axially upper side of the insulating plate 23. The sealing plate 22 has an annular projection 70 that protrudes axially toward the electrode body 14 side (axially downward). At least the lower end of the annular projection 70 is housed in the recess 65 and contacts the insulating plate 23, pressing the insulating plate 23 axially downward. At least a portion of the annular projection 70 is positioned to overlap with the terminal plate 21 in the axial direction.

[0030] Next, the effects of the battery 10 of this disclosure will be explained. Figure 3 is an enlarged cross-sectional view of the battery 310 of the reference example, corresponding to Figure 2. The battery 310 of the reference example differs from the battery 10 in that the insulating plate 323 does not have a recess and the sealing plate 322 does not have a protrusion. In the battery 10 of the reference example, when the internal pressure of the battery 310 approaches the expected rupture pressure due to abnormal heat generation, the valve portion 322A inverts so that it becomes convex in the axial direction upward, as shown in Figure 4. Simultaneously with this inversion, the central portion 21B is separated from the annular portion 21A, or, as shown in Figure 4, detaches from the valve portion 322A. Since the valve portion 322A is insulated from the annular portion 21A by the insulating plate 323, the current path is interrupted by this inversion. Therefore, further temperature rise is suppressed, and high safety can be achieved.

[0031] However, considering various worst-case scenarios, as shown in Figure 5, if, for example, the internal pressure of the battery gradually increases over a long period of time, the gasket 24 may deteriorate over time, causing the sealing plate 322 to deform and be displaced axially outward. Furthermore, as a last resort, the terminal plate 21 may deform in a way that it protrudes axially towards the sealing plate 322 as a result of the above deformation of the sealing plate 322. Consequently, the joint between the sealing plate 322 and the terminal plate 21 may become less prone to fracture even when the pressure is close to the expected fracture pressure.

[0032] In contrast, with the battery 10 of this embodiment, as shown in Figure 6, in most cases, similar to the battery 310 of the reference example, if the battery 10 overheats abnormally and the internal pressure rises to near the expected rupture pressure, the valve portion 22A inverts so that it becomes convex axially upward, using the radially outward annular end 22B, which has low rigidity in the thin-walled portion 34, as a fulcrum. Simultaneously with this inversion, the central portion 21B is separated from the annular portion 21A or detaches from the valve portion 22A. Since the valve portion 22A is insulated from the annular portion 21A by the insulating plate 23, the current path is interrupted by this inversion. This interruption suppresses the overheating of the battery 10. If the internal pressure of the battery rises further, the annular end 22B of the thin-walled portion 34 ruptures, forming a gas outlet. As a result, high-temperature gas and molten material are discharged to the outside of the battery 10, and the battery 10 becomes safe.

[0033] Furthermore, in the battery 10 of this embodiment, the annular projection 70 presses the terminal plate 21 downward in the axial direction via the insulating plate 23. As shown in Figure 7, even if the sealing plate 22 deforms to be displaced outward in the axial direction, the deformation of the terminal plate 21 to become convex towards the sealing plate 22 in the axial direction is suppressed. Therefore, even if the sealing plate 22 deforms to be displaced outward in the axial direction, the rupture of the joint between the sealing plate 22 and the terminal plate 21 is more likely to occur near the expected rupture pressure, thus ensuring complete safety.

[0034] It is preferable that the depth of the recess 65 is 10% or more of the maximum axial thickness of the portion 80 (see Figure 2) of the insulating plate 23 that is positioned between the sealing plate 22 and the terminal plate 21 in the axial direction, as this effectively suppresses deformation of the terminal plate 21 so that deformation becomes convex toward the sealing plate 22 in the axial direction, and effectively suppresses the phenomenon that fracture of the joint between the sealing plate 22 and the terminal plate 21 does not occur near the expected fracture pressure.

[0035] In the battery 10 of this embodiment, since the insulating plate 23 has a recess 65, it is possible to suppress the excessive pressing force of the annular projection 70 against the insulating plate 23, and effectively suppress damage to the insulating plate 23. Also, since the projection is an annular projection 70, the terminal plate 21 is pressed downward in the axial direction along its entire circumference. Therefore, it is possible to effectively suppress deformation of the terminal plate 21 so that it protrudes towards the sealing plate 22 in the axial direction, and effectively suppress the phenomenon in which the joint between the sealing plate 22 and the terminal plate 21 does not break near the expected breaking pressure.

[0036] It is preferable that the annular projection 70 is positioned so that the entire annular projection 70 overlaps the terminal plate 21 in the axial direction, as this allows a large force to be applied from the annular projection 70 to the terminal plate 21, effectively suppressing deformation of the terminal plate 21 so that it protrudes towards the sealing plate 22 in the axial direction. Furthermore, it is preferable that a portion 35b of the inner circumferential surface 35a (see Figure 2) on the space 39 side of the thickened portion 35 is included in the annular projection 70, as this allows the annular projection 70 to be provided on the radially inward side, effectively suppressing deformation of the terminal plate 21 so that it protrudes towards the sealing plate 22 in the axial direction.

[0037] The case in which the sealing plate 22 has an annular projection 70 has been described. However, the sealing plate may have one or more projections that are not annular. In that case, it is preferable that the projections have an arc shape in a plan view when viewed from the axial direction, and in order to effectively suppress deformation of the terminal plate, it is preferable that the circumferential range in which one or more projections are provided is 120 degrees or more. Furthermore, if the sealing plate has multiple projections arranged at intervals, it is preferable that the multiple projections are substantially identical and have an arc shape in a plan view, and that they are arranged at substantially equal intervals in the circumferential direction.

[0038] This disclosure is not limited to the above embodiments and their modifications, and various improvements and modifications are possible within the scope of the claims of this application and their equivalents. Figure 8 is an enlarged cross-sectional view corresponding to Figure 2 of the battery 110 of the first modification. As shown in Figure 8, the insulating plate 123 does not have to have a recess when it is an insulating plate alone. Even in this case, the annular projection 70 of the sealing plate 22 presses the upper end face 129 of the insulating plate 123 downward, making it easy for a shallow recess to form on the upper end face 129. Furthermore, an axial gap 168 is easily formed between the sealing plate 22 and the insulating plate 123 radially outward from the annular projection 70. In the battery 110 as well, a downward force from the annular projection 70 can be applied to the terminal plate 21 via the insulating plate 123, so that the terminal plate 21 does not deform to become convex toward the sealing plate 22 in the axial direction.Therefore, the phenomenon in which the rupture of the joint between the sealing plate 22 and the terminal plate 21 does not occur near the expected rupture pressure can be effectively suppressed.

[0039] Figure 9 is an enlarged cross-sectional view corresponding to Figure 2 of a second modified battery 210. As shown in Figure 9, the sealing plate 222 may have a main body portion 290, a separate portion 291, and a joining portion 292 that joins the main body portion 290 and the separate portion 291, and the projection 270 may include the separate portion 291. The joining portion 292 between the main body portion 290 and the separate portion 291 is composed of, for example, an adhesive layer, a welded portion, or a solder layer.

[0040] With the battery 210, the hardness of the separate part 291 can be set independently of the hardness of the main body 290, and the force with which the projection 270 presses the terminal plate 21 downwards via the insulating plate 23 can be easily adjusted. For example, in the battery 210, if the hardness of the separate part 291 is made higher than the hardness of the main body 290, the force with which the projection 270 presses the terminal plate 21 downwards via the insulating plate 23 can be increased compared to when the main body and projection are integrally manufactured from the same material using machining or die casting.

[0041] The case described above is one in which the positive electrode lead 17 is an electrode lead electrically connected to the terminal board 21, the positive electrode 11 is electrically connected to the sealing body 19, and the negative electrode 12 is electrically connected to the outer can 20. However, the negative electrode lead may also be an electrode lead electrically connected to the terminal board, and the negative electrode may be electrically connected to the sealing body and the positive electrode may be electrically connected to the outer can.

[0042] Furthermore, the cylindrical battery of this disclosure may have the following configurations: Configuration 1: A cylindrical battery comprising an electrode body, an outer casing housing the electrode body, and a sealing body that closes the opening of the outer casing via a gasket, wherein the sealing body has a sealing plate, a terminal plate to which electrode leads extending from the electrode body are joined and to which the sealing plate is joined on the radially central side, and an annular insulating plate that includes a clamping portion sandwiched between the sealing plate and the terminal plate and is insulating, wherein the sealing plate includes a projection that protrudes toward the electrode body in the axial direction, and at least a part of the projection is positioned to overlap with the terminal plate in the axial direction. Configuration 2: The cylindrical battery according to Configuration 1, wherein the insulating plate has a recess that accommodates at least a part of the projection. Configuration 3: The cylindrical battery according to Configuration 2, wherein the depth of the recess is 10% to 75% of the maximum axial thickness of the portion of the insulating plate positioned between the sealing plate and the terminal plate in the axial direction. Configuration 4: The cylindrical battery according to Configuration 1, wherein an axial gap is created between the sealing plate and the insulating plate radially outward from the projection. Configuration 5: The cylindrical battery according to any one of Configurations 1 to 4, wherein the projection is an annular projection. Configuration 6: The cylindrical battery according to any one of Configurations 1 to 5, wherein the sealing plate has a main body, a separate body, and a joint that connects the main body and the separate body, and the projection includes the separate body. Configuration 7: The cylindrical battery according to Configuration 6, wherein the hardness of the separate body is higher than the hardness of the main body.

[0043] 10, 110, 210 Battery, 11 Positive electrode, 12 Negative electrode, 13 Separator, 14 Electrode body, 15 Upper insulating plate, 16 Lower insulating plate, 17 Positive lead, 18 Negative lead, 19 Sealing body, 20 Outer can, 20A Bottom, 20B Cylindrical part, 21 Terminal plate (rupture plate), 21A Annular part, 21B Center part, 21C Ventilation hole, 22, 222 Sealing plate, 22A Valve part, 22B Annular end, 23, 123 Insulating plate, 23A Opening, 23B Ventilation hole, 24 Gasket, 28 Grooved part, 29 Shoulder part, 31 Peripheral part, 33 Protruding part, 34 Thin-walled part, 35 Thickened portion, 35a inner circumferential surface, 35b part of the inner circumferential surface, 37, 38 annular projection, 39 space, 43 clamping portion, 65 recess, 70 annular projection, 80 portion of the insulating plate positioned between the sealing plate and the terminal plate in the axial direction, 129 upper end face of the insulator, 168 gap, 270 projection, 290 main body portion, 291 separate portion, 292 joint portion.

Claims

Electrode body and An outer container housing the electrode body, The outer can is equipped with a sealing body that closes the opening via a gasket, The sealing body comprises a sealing plate, a terminal plate to which electrode leads extending from the electrode body are joined and to which the sealing plate is joined on the radially central side, and an annular insulating plate that includes a clamping portion sandwiched between the sealing plate and the terminal plate and is insulating, The sealing plate includes a projection that protrudes axially toward the electrode body, A cylindrical battery in which at least a portion of the projection is positioned to overlap the terminal plate in the axial direction. 　 The cylindrical battery according to claim 1, wherein the insulating plate has a recess that accommodates at least a portion of the projection. 　 The cylindrical battery according to claim 2, wherein the depth of the recess is 10% to 75% of the maximum axial thickness of the portion of the insulating plate that is positioned between the sealing plate and the terminal plate in the axial direction. 　 The cylindrical battery according to claim 1, wherein an axial gap is formed between the sealing plate and the insulating plate on a radially outward side of the projection. 　 The cylindrical battery according to any one of claims 1 to 4, wherein the projection is an annular projection. 　 The sealing plate has a main body, a separate body, and a joining portion that connects the main body and the separate body. The cylindrical battery according to any one of claims 1 to 4, wherein the projection includes the separate body portion. 　 The cylindrical battery according to claim 6, wherein the hardness of the separate part is higher than the hardness of the main body.

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