Cylindrical battery

Abstract

Provided is a cylindrical battery (10) having a wound electrode body (14) in which a positive electrode (11) and a negative electrode (12) including a negative electrode core (40) and a negative electrode mixture layer (41) are wound in a spiral shape with a separator (13) therebetween. The negative electrode (12) has an adhesive tape (50) bonded to the winding inner surface so as to straddle, in the winding direction, a first facing position (12A) facing the winding inner side of the winding start-side end (11A) of the positive electrode (11).

Description

Technical Field

[0001] The present application relates to a cylindrical battery. Background Art

[0002] Cylindrical batteries have a spirally wound electrode assembly consisting of a positive electrode and a negative electrode with a separator interposed therebetween. Repeated charge and discharge cycles in cylindrical batteries cause the positive and negative electrodes to expand and contract, sometimes leading to plate deformation, where at least one of the positive and negative electrodes is partially deformed.

[0003] For example, Patent Document 1 discloses a cylindrical battery having a wound electrode assembly having an insulating tape attached to the negative electrode so as to straddle the surface of the negative electrode lead in the winding direction in order to suppress deformation of the joint portion of the negative electrode lead.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: International Publication No. 2018 / 180748 Summary of the Invention

[0007] However, in cylindrical batteries, the positive electrode's winding start end forms a step along the winding direction. Consequently, the negative electrode portion facing the inner side of the winding start end of the positive electrode may deform during charge and discharge cycles. This deformation of the negative electrode causes the distance between the positive and negative electrodes to vary, leading to uneven charge and discharge reactions and potentially deteriorating cycle characteristics.

[0008] The insulating tape of Patent Document 1 may not be able to adequately suppress deformation of the negative electrode portion facing the inner side of the winding start end of the positive electrode where the step is formed. Furthermore, in Patent Document 1, there is concern that the capacity of the cylindrical battery may be reduced due to the insulating tape being applied to the negative electrode.

[0009] Therefore, an object of the present application is to provide a cylindrical battery capable of suppressing deformation of the negative electrode portion facing the winding start side end of the positive electrode during charge and discharge cycles.

[0010] The cylindrical battery of the present application is characterized in that it has an electrode body formed by winding a positive electrode and a negative electrode comprising a core body and a mixture layer into a spiral shape with a separator therebetween, and the negative electrode has a tape adhered to the inner surface of the winding in a manner that spans a first opposing position opposite to the inner side of the winding at the side end where the winding starts, along the winding direction.

[0011] According to the cylindrical battery of the present application, deformation of the negative electrode portion facing the winding start side end of the positive electrode during charge and discharge cycles can be suppressed. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 This is an axial cross-sectional view of a cylindrical battery as an example of an embodiment.

[0013] Figure 2 It is a schematic diagram showing a radial cross section of the electrode assembly at the winding start side.

[0014] Figure 3 This is a schematic diagram showing the electrode assembly unfolded from the winding start side.

[0015] Figure 4 Yes Figure 3 Schematic diagram of the radial cross section. DETAILED DESCRIPTION

[0016] In the following description, specific shapes, materials, directions, numerical values, etc. are illustrative for facilitating understanding of the present application and may be appropriately changed according to application, purpose, specifications, etc.

[0017] Cylindrical battery

[0018] use Figure 1 A cylindrical battery 10 as an example of an embodiment will be described.

[0019] The cylindrical battery 10 includes a positive electrode 11, a negative electrode 12, and a separator 13, and has an electrode body 14 formed by winding the positive electrode 11 and the negative electrode 12 with the separator 13 interposed therebetween. In addition, the cylindrical battery 10 includes a bottomed cylindrical outer can 16 that accommodates the electrode body 14, and a sealing body 17 that closes the opening of the outer can 16. The outer can 16 accommodates an electrolyte together with the electrode body 14. The outer can 16 has a groove 22 formed in the side wall, and the sealing body 17 is supported by the groove 22 to close the opening of the outer can 16. In the following, for the convenience of description, the sealing body 17 side of the cylindrical battery 10 is set as the upper side, and the bottom side of the outer can 16 is set as the lower side.

[0020] Although details will be described later, the negative electrode 12 includes a negative electrode core 40 and a negative electrode mixture layer 41, and has a tape 50 attached to the inner surface of the winding so as to span a first facing position 12A facing the winding start end 11A of the positive electrode 11 in the winding direction. The tape 50 can suppress deformation of the portion of the negative electrode 12 facing the inner side of the winding at the winding start end of the positive electrode 11 during charge and discharge cycles.

[0021] The electrolyte can be an aqueous electrolyte, but in this embodiment, a non-aqueous electrolyte is used. The non-aqueous electrolyte has lithium ion conductivity. The non-aqueous electrolyte can be a liquid electrolyte (electrolyte) or a solid electrolyte. The cylindrical battery 10 is, for example, a non-aqueous electrolyte secondary battery, preferably a lithium ion battery.

[0022] The liquid electrolyte (electrolyte) contains 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 thereof. Examples of non-aqueous solvents include ethylene carbonate (EC), ethyl methyl carbonate (EMC), dimethyl carbonate (DMC), diethyl carbonate (DEC), and mixed solvents thereof. The non-aqueous solvent may contain a halogen-substituted product (e.g., fluoroethylene carbonate) in which at least a portion of the hydrogen atoms in these solvents are replaced with halogen atoms such as fluorine. Examples of the electrolyte salt include lithium salts such as LiPF6.

[0023] As a solid electrolyte, for example, a solid or gel-like polymer electrolyte, an inorganic solid electrolyte, etc. can be used. As an inorganic solid electrolyte, materials known in all-solid-state lithium-ion secondary batteries, etc. (for example, oxide-based solid electrolytes, sulfide-based solid electrolytes, halogen-based solid electrolytes, etc.) can be used. A polymer electrolyte, for example, comprises a lithium salt and a matrix polymer, or comprises a non-aqueous solvent, a lithium salt, and a matrix polymer. As the matrix polymer, for example, a polymer material that gels after absorbing a non-aqueous solvent can be used. Examples of polymer materials include fluororesins, acrylic resins, and polyether resins.

[0024] As described above, the electrode body 14 has a wound structure in which the positive electrode 11 and the negative electrode 12 are wound into a spiral shape with the separator 13 interposed therebetween. The positive electrode 11, the negative electrode 12, and the separator 13 are all long strips in the form of strips, which are wound into a spiral shape and are thus alternately stacked along the radial direction of the electrode body 14. In order to prevent the precipitation of lithium, the negative electrode 12 is formed to be one circle larger than the positive electrode 11. That is, the negative electrode 12 is formed to be longer in the length direction and the width direction than the positive electrode 11. The separator 13 is formed to be at least one circle larger than the positive electrode 11, for example, two pieces are arranged in a manner to sandwich the positive electrode 11.

[0025] The electrode body 14 has a positive electrode lead 20 connected to the positive electrode 11 and a negative electrode lead 21 connected to the negative electrode 12. In this embodiment, the positive electrode lead 20 is provided at the longitudinal center of the positive electrode 11 and at a position away from the winding start side and the winding end side of the electrode body 14. On the other hand, the negative electrode lead 21 is provided at one longitudinal end of the negative electrode 12 located on the winding start side of the electrode body 14. The negative electrode 12 has a first core exposed portion 43 (see Figures 2 to 4 The negative electrode lead 21 is joined to the core exposed portion 43 .

[0026] The positive electrode 11 includes a positive electrode core 30 and a positive electrode mixture layer 31 formed on at least one surface of the core. The positive electrode core 30 can be made of a foil of a metal such as aluminum or an aluminum alloy that is stable in the potential range of the positive electrode 11, or a film having the metal disposed on the surface. The positive electrode mixture layer 31 contains a positive electrode active material, a conductive agent such as acetylene black, and a binder such as polyvinylidene fluoride (PVdF), and is preferably formed on both surfaces of the positive electrode core 30. The thickness of the positive electrode mixture layer 31 is, for example, not less than 40 μm and not more than 100 μm. The positive electrode active material uses, for example, a lithium transition metal composite oxide containing Ni, Co, Mn, Al, etc. It should be noted that the positive electrode lead 20 is preferably directly bonded to the positive electrode core 30 by ultrasonic welding or the like.

[0027] The negative electrode 12 includes a negative electrode core 40 and a negative electrode mixture layer 41 formed on at least one surface of the core. The negative electrode core 40 can be made of a foil of a metal such as copper or a copper alloy that is stable within the potential range of the negative electrode 12, or a film having the metal disposed on the surface. The negative electrode mixture layer 41 contains a negative electrode active material and a binder such as styrene-butadiene rubber (SBR), and is preferably formed on both surfaces of the negative electrode core 40. The thickness of the negative electrode mixture layer 41 is, for example, not less than 40 μm and not more than 100 μm. For example, graphite or a Si-containing material is used as the negative electrode active material. The negative electrode lead 21 is preferably directly bonded to the negative electrode core 40 by ultrasonic welding or the like.

[0028] The cylindrical battery 10 includes an upper insulating plate 18 positioned between the sealing member 17 and the electrode assembly, and having an opening through which the positive electrode lead 20 is passed. In this specification, the electrode assembly refers to the portion of the electrode assembly 14 consisting of the positive electrode 11, the negative electrode 12, and the separator 13, excluding the positive electrode lead 20 and the negative electrode lead 21. Furthermore, the cylindrical battery 10 includes a lower insulating plate 19 positioned between the bottom of the outer can 16 and the electrode assembly, and having an opening through which the negative electrode lead 21 is passed.

[0029] Figure 1 In the example shown, the positive electrode lead 20 extends through the opening of the upper insulating plate 18 toward the sealing body 17, while the negative electrode lead 21 extends through the opening of the lower insulating plate 19 toward the bottom of the outer can 16. The positive electrode lead 20 is connected to the lower surface of the bottom plate 23 of the sealing body 17 by welding or other means, with the sealing body 17 serving as the positive electrode terminal. The negative electrode lead 21 is connected to the inner bottom surface of the outer can 16 by welding or other means, with the outer can 16 serving as the negative electrode terminal.

[0030] The negative electrode 12 is arranged on the outermost peripheral surface of the electrode body 14, and a second core exposure portion 44 is provided to expose the surface of the negative electrode core 40. In addition, the core exposure portion 44 is in contact with the inner peripheral surface of the outer packaging can 16. By making the core exposure portion 44 abut against the inner peripheral surface of the outer packaging can 16 serving as the negative terminal, the two end portions in the longitudinal direction of the negative electrode 12 can be electrically connected to the outer packaging can 16, thereby ensuring good current collection. Although the core exposure portion 44 can also be provided on a part of the outermost peripheral surface of the electrode body 14, it is preferably provided on the entire area of ​​the outermost peripheral surface. For example, a portion where the negative electrode mixture layer 41 is not present is provided on both sides of the negative electrode core 40 with a length of more than one week of the electrode body 14 from the winding end of the negative electrode 12.

[0031] The outer can 16 is a cylindrical metal container with a bottom. A gasket 28 is placed between the outer can 16 and the sealing body 17, hermetically sealing the interior of the battery. The outer can 16 has a groove 22 formed, for example, by pressing the side surface from the outside. The groove 22 is preferably formed in an annular shape along the circumference of the outer can 16, with its upper surface supporting the sealing body 17. Furthermore, the upper end of the outer can 16 is bent inward and fastened to the peripheral edge of the sealing body 17.

[0032] The sealing body 17 has a structure in which a bottom plate 23, a lower valve body 24, an insulating member 25, an upper valve body 26 and a cover 27 are stacked in sequence from the electrode body 14 side. The various components constituting the sealing body 17 have, for example, a disc shape or a ring shape, and the components except the insulating member 25 are electrically connected to each other. The lower valve body 24 and the upper valve body 26 are connected to each other at their respective central portions, and an insulating member 25 is sandwiched between their respective peripheral portions. When the internal pressure of the battery rises, the lower valve body 24 is deformed and broken in a manner that pushes the upper valve body 26 toward the cover 27 side, thereby blocking the current path between the lower valve body 24 and the upper valve body 26. When the internal pressure rises further, the upper valve body 26 breaks, and gas is discharged from the opening of the cover 27.

[0033] [adhesive tape]

[0034] use Figures 2 to 4 The adhesive tape 50 will be described. Figure 2 It is a cross-sectional view perpendicular to the winding axis direction on the winding start side of the electrode body 14 (a cross-sectional view along the stacking direction of the electrode body 14 ). Figure 3 It is a schematic diagram showing the electrode assembly 14 unfolded from the winding start side. Figure 4 Yes Figure 3 Schematic diagram of the radial cross section. Figures 2 to 4 In order to make the drawing clear, the illustration of the spacer 13 is omitted.

[0035] The tape 50 is attached to the inner surface of the negative electrode 12 at the winding start side. More specifically, the tape 50 is attached so as to span the portion of the inner surface of the negative electrode 12 that faces the inner side of the winding start end 11A of the positive electrode 11. That is, the winding start end 50A of the tape 50 is located closer to the winding start side than the first facing position 12A, and the winding end end 50B of the tape 50 is located closer to the winding end side than the first facing position 12A. It should be noted that, as described above, the positive electrode mixture layer 31 is formed on the positive electrode core 30 at the winding start end 11A of the positive electrode 11.

[0036] In the cylindrical battery 10, the positive electrode 11 has a height difference along the winding direction at its winding start end 11A. Therefore, when repeated charge and discharge cycles are performed, the portion of the negative electrode 12 facing the inner side of the winding start end of the positive electrode may deform. This partial deformation of the negative electrode 12 causes the distance between the positive and negative electrodes to vary, leading to uneven charge and discharge reactions and potentially deteriorating cycle characteristics.

[0037] The tape 50 reinforces the portion of the negative electrode 12 facing the inner side of the winding start end 11A of the positive electrode 11 where the step is formed, thereby suppressing deformation of the portion of the negative electrode 12. This suppresses variations in the distance between the positive and negative electrodes, preventing uneven charge and discharge reactions and deterioration in cycle characteristics.

[0038] Furthermore, since the tape 50 is attached to the inner surface of the negative electrode 12 at the winding start side that does not participate in the electrolytic reaction, the electrolytic reaction is not hindered by the tape 50 , thereby preventing a decrease in the battery capacity of the cylindrical battery 10 .

[0039] Here, the position of the winding end end 50B of the tape 50 will be described in detail. The winding end end 50B of the tape 50 is located at least 2 mm further to the winding end side than the first facing position 12A. This ensures that the portion of the negative electrode 12 that faces the winding start end 11A of the positive electrode 11, which forms the step, can be reliably reinforced.

[0040] Furthermore, the winding end 50B of the tape 50 is located closer to the winding start side than the second facing position 12B. That is, the tape 50 is attached to the negative electrode 12 so as to face the positive electrode 11 without the separator 13 interposed therebetween. This prevents the electrolytic reaction from being hindered by the tape 50, and prevents a decrease in the battery capacity of the cylindrical battery 10.

[0041] The position of the winding start end 50A of the tape 50 will be described in detail below. The winding start end 50A of the tape 50 is located closer to the winding start side than the winding start end 41A of the negative electrode mixture layer 41 on the inner surface of the wound negative electrode 12. More specifically, the winding start end 50A is preferably located at least 2 mm further to the winding start side than the winding start end 41A of the negative electrode mixture layer 41. This ensures that the portion of the negative electrode 12 facing the winding start end 11A of the positive electrode 11 can be more reliably reinforced.

[0042] The winding start end 50A of the tape 50 is preferably located on the winding end side relative to the negative electrode lead 21. In other words, the winding start end 50A of the tape 50 preferably does not straddle the negative electrode lead 21. This prevents the tape 50 from being unnecessarily lengthened.

[0043] The length (width) of the tape 50 in the winding axis direction will be described in detail. The length of the tape 50 in the winding axis direction is preferably at least 60% of the length of the negative electrode 12 in the winding axis direction, and more preferably at least 80%. Furthermore, the center position of the tape 50 in the winding axis direction is preferably substantially aligned with the center position of the negative electrode 12 in the winding axis direction. This allows for more reliable reinforcement of the portion of the negative electrode 12 that faces the winding start end 11A of the positive electrode 11.

[0044] The tape 50 preferably has insulating properties. However, when the tape 50 is attached to the area of ​​the negative electrode 12 that faces the positive electrode 12 without the separator 13 interposed therebetween, it is not necessary to specifically have insulating properties. The tape 50 includes, for example, a tape base material and an adhesive layer formed on one side of the base material, and is attached to the inner surface of the wound negative electrode 12 via the adhesive layer.

[0045] Examples of the resin constituting the tape base include polyesters such as polyethylene terephthalate (PET), polypropylene (PP), polyimide (PI), polyphenylene sulfide (PPS), polyetherimide (PEI), and polyamide. The adhesive constituting the adhesive layer preferably exhibits adhesive strength at room temperature. Examples of adhesives include acrylic adhesives and synthetic rubber adhesives. It should be noted that the tape 50 may contain an insulating inorganic filler.

[0046] It should be noted that the present application is not limited to the above-mentioned embodiments and their modifications, and various changes and improvements can be made within the scope of the matters described in the technical claims of the present application.

[0047] The present application is further described below using experimental examples, but the present application is not limited to these experimental examples.

[0048] <Experimental Example 1>

[0049] [Production of positive electrode]

[0050] Lithium nickel oxide (LiNi 0.88 Co 0.09 Al 0.03 O2) as the positive electrode active material. The positive electrode active material, acetylene black, and polyvinylidene fluoride were mixed at a solid content mass ratio of 98:1:1, and N-methylpyrrolidone (NMP) was used as the dispersion medium to prepare a positive electrode mixture slurry. The slurry was applied to both sides of a positive electrode core made of a long strip of aluminum foil with a thickness of 15μm. The coating was dried and compressed to obtain a positive electrode (width 58.0mm, length 850mm, thickness 110μm) with a positive electrode mixture layer formed on both sides of the positive electrode core. It should be noted that an exposed core portion without a positive electrode mixture layer was provided in the center of the longitudinal direction of the positive electrode. An aluminum positive electrode lead was ultrasonically welded to this exposed portion, and PI tape was affixed to both sides to protect the exposed portion of the current collector.

[0051] [Production of negative electrode]

[0052] A mixture of graphite powder and a Si-containing material at a mass ratio of 95:5 was used as the negative electrode active material. A negative electrode mixture slurry was prepared by mixing the negative electrode active material, a dispersion of styrene-butadiene rubber, and sodium carboxymethylcellulose at a solids mass ratio of 98:1:1, using water as the dispersion medium. This slurry was applied to both sides of a negative electrode core made of an 8μm-thick strip of copper foil. The coating was dried and compressed to produce a negative electrode (59.3mm wide, 955mm long, 114μm thick) with a negative electrode mixture layer formed on both sides of the negative electrode core. It should be noted that first and second exposed core sections, without any negative electrode mixture layer, were provided within a specified length from both ends of the negative electrode in the longitudinal direction. A nickel negative electrode lead was ultrasonically welded to the first exposed core section.

[0053] [Electrode body production]

[0054] The positive electrode, negative electrode, and polyethylene separator are spirally wound using a cylindrical core member to form a wound electrode assembly. The negative electrode is positioned so that the exposed first core portion of the negative electrode, to which the negative electrode lead is attached, is located at the start of winding of the electrode assembly. In other words, the exposed second core portion of the negative electrode is located at the end of winding of the electrode assembly. After the electrode assembly is wound, the core member is removed, resulting in a wound electrode assembly with a cavity formed in the core portion.

[0055] In Experimental Example 1, tape was applied to the inner surface of the negative electrode lead, starting from the winding end of the negative electrode lead, so as to straddle the negative electrode mixture layer. The tape was positioned so that the winding end of the tape was closer to the winding start than the first facing position on the negative electrode, which serves as the inner facing position of the positive electrode winding start. The tape was made of polypropylene and had a thickness of 0.03 mm. The tape's length along the winding axis was 50 mm.

[0056] [Preparation of non-aqueous electrolyte]

[0057] To 100 parts by mass of a mixed solvent of ethylene carbonate (EC) and dimethyl carbonate (DMC) at a volume ratio of 1:3 (25° C.) was added 5 parts by mass of vinylene carbonate (VC), and LiPF6 was dissolved at 1.3 mol / L to prepare a non-aqueous electrolyte.

[0058] [Production of Cylindrical Batteries]

[0059] After placing insulating plates above and below the electrode assembly, the negative electrode lead is welded to the inner bottom surface of a cylindrical outer can. The positive electrode lead is welded to the terminal plate inside the sealing member. The electrode assembly is then housed within the outer can. A non-aqueous electrolyte is then injected into the outer can under reduced pressure. The opening of the outer can is sealed with the sealing member via a gasket, thereby completing a cylindrical battery. The exposed portion of the negative electrode's second core forms the outermost surface of the electrode assembly and contacts the inner circumference of the outer can.

[0060] <Experimental Example 2>

[0061] A cylindrical battery was produced in the same manner as in Example 1 except that the winding end side end of the tape was positioned 2 mm further to the winding end side than the first facing position.

[0062] <Experimental Example 3>

[0063] A cylindrical battery was produced in the same manner as in Experimental Example 2 except that the length of the tape in the winding axis direction was set to 30 mm.

[0064] [Evaluation of electrode plate deformation (presence of buckling)]

[0065] The batteries of each experimental example were subjected to 200 or fewer charge and discharge cycles. A cross-section of the central portion of the battery was then observed using an X-ray CT scanner to confirm deformation of the negative electrode portion facing the inner side of the winding start end of the positive electrode.

[0066] Charging: 3000mA (1C) -4.20V 100mA cut-off pause 30 minutes

[0067] Discharge: 15000mA (5C) -2.50V cut-off pause 60 minutes

[0068] [Table 1]

[0069]

[0070] As shown in Table 1, the batteries of Experimental Examples 1 and 3 exhibited buckling deformation, with the negative electrode portion facing the inner side of the positive electrode at the winding start end bending inward. In the battery of Experimental Example 2, no buckling deformation was observed in the negative electrode portion.

[0071] In addition, the present application is further described by the following embodiments.

[0072] Configuration 1: A cylindrical battery comprising an electrode body formed by spirally winding a positive electrode and a negative electrode comprising a core and a mixture layer with a separator interposed therebetween, wherein the negative electrode has a tape adhered to the inner surface of the winding in a manner spanning a first opposing position opposite to the inner side of the winding at the winding start side end of the positive electrode in the winding direction.

[0073] Configuration 2: The cylindrical battery according to Configuration 1, wherein the end of the tape at the winding end side is located at a position 2 mm or more closer to the winding end side than the first facing position.

[0074] Configuration 3: The cylindrical battery according to Configuration 1 or 2, wherein the end portion of the tape on the winding start side is located on the winding start side relative to the end portion of the mixture layer on the winding inner surface.

[0075] Configuration 4: The cylindrical battery according to any one of Configurations 1 to 3, wherein the length of the tape in the winding axis direction is 60% or more of the length of the negative electrode in the winding axis direction.

[0076] Configuration 5: The cylindrical battery according to any one of Configurations 1 to 4, wherein the winding end of the tape is located closer to the winding start side than a second facing position of the negative electrode facing the outer side of the winding start end of the positive electrode.

[0077] Description of Reference Numerals

[0078] 10 Cylindrical battery, 11 Positive electrode, 11A Winding start end (positive electrode), 12 Negative electrode, 12A 1st opposing position, 12B 2nd opposing position, 13 Separator, 14 Electrode body, 16 Outer can, 17 Sealing body, 18 Upper insulating plate, 19 Lower insulating plate, 20 Positive electrode lead, 21 Negative electrode lead, 22 Grooved portion, 23 Bottom plate, 24 Lower valve body, 25 Insulating member, 26 Upper valve body, 27 Lid, 28 Gasket, 30 Positive electrode core, 31 Positive electrode mixture layer, 40 Negative electrode core, 41 Negative electrode mixture layer, 41A Winding start end (negative electrode mixture layer), 43 Core exposed portion (1st), 44 Core exposed portion (2nd), 50 Tape, 50A Winding start end (tape), 50B End of winding (tape).

Claims

1. A cylindrical battery comprising an electrode body in which a positive electrode and a negative electrode including a core and a mixture layer are wound in a spiral shape with a separator interposed therebetween. The negative electrode has a tape attached to the inner surface of the winding so as to span a first facing position facing the inner side of the winding at the winding start side end of the positive electrode in the winding direction.

2. The cylindrical battery according to claim 1, wherein The winding end side end of the adhesive tape is located at a position 2 mm or more closer to the winding end side than the first facing position.

3. The cylindrical battery according to claim 2, wherein: The winding start side end of the adhesive tape is located on the winding start side relative to the winding start side end of the mixture layer on the winding inner surface.

4. The cylindrical battery according to claim 3, wherein The length of the tape in the winding axis direction is 60% or more of the length of the negative electrode in the winding axis direction.

5. The cylindrical battery according to any one of claims 1 to 4, wherein The winding end side end of the tape is located on the winding start side with respect to a second facing position of the negative electrode that faces the winding outer side of the winding start side end of the positive electrode.

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