Non-aqueous electrolyte secondary battery

Abstract

This non-aqueous electrolyte secondary battery comprises: an electrode body (14) in which a positive electrode (11) and a negative electrode (12) are wound with a separator (13) interposed therebetween; and a bottomed cylindrical exterior can for accommodating the electrode body (14). The positive electrode (11) has a starting end part (50) on the winding outer side of the negative electrode (12). The negative electrode (12) has a negative electrode lead (21) of which one end is joined to the starting-end-part (70) side of the negative electrode (12) and of which the other end is joined to the exterior can. In the negative electrode (12), an adhesive tape (60) is affixed to the reverse surface of a position A facing the starting end part (50) of the positive electrode (11).

Description

Non-aqueous electrolyte secondary battery 【0001】 The present disclosure relates to a non-aqueous electrolyte secondary battery, and particularly to the structure of the electrodes of a non-aqueous electrolyte secondary battery. 【0002】 Conventionally, a battery has been proposed that includes a wound electrode body in which the negative electrode has a non-opposing portion that does not face the positive electrode on the winding start side. Patent Document 1 discloses a battery in which the non-opposing portion of the negative electrode is wound first, thereby securing an exhaust passage in the inner peripheral portion of the wound electrode body during ignition of the secondary battery. 【0003】 International Application Publication WO2018 / 116876A1 Pamphlet 【0004】 However, in the battery disclosed in Patent Document 1, when charge and discharge are repeated, as a result of stress concentrating on the end portion of the electrode plate due to the expansion and contraction of the electrode, the start end portion of the positive electrode may be pressed, and the negative electrode constituting the inner peripheral portion of the electrode body may be deformed. Since the deformation of the electrode plate leads to a deterioration in battery performance, a wound electrode body having a negative electrode with rigidity against the stress accompanying the expansion and contraction of the electrode is required. 【0005】 The non-aqueous electrolyte secondary battery according to the present disclosure is a non-aqueous electrolyte secondary battery including an electrode body in which a positive electrode and a negative electrode are wound via a separator, and a bottomed cylindrical exterior can for housing the electrode body. The positive electrode has a start end portion on the outer side of the winding of the negative electrode, the negative electrode has a negative electrode lead in which one end is joined to the start end portion side of the negative electrode and the other end is joined to the exterior can, and the negative electrode is characterized in that an adhesive tape is attached to the back surface at a position facing the start end portion of the positive electrode. 【0006】 According to the non-aqueous electrolyte secondary battery according to the present disclosure, it is possible to provide a non-aqueous electrolyte secondary battery in which the negative electrode constituting the inner peripheral portion of the electrode body has rigidity and suppresses deformation of the electrode plate. The non-aqueous electrolyte secondary battery according to the present disclosure is excellent in, for example, charge-discharge cycle characteristics. 【0007】 It is a cross-sectional view in the axial direction of a non-aqueous electrolyte secondary battery which is an example of an embodiment. It is a cross-sectional view in the developed state of an electrode which is an example of an embodiment. It is a cross-sectional view in the radial direction of an electrode which is an example of an embodiment. It is a front view of the start end of the winding of the negative electrode in Examples, Comparative Examples, and Reference Examples used in an experiment conducted to confirm the effects of the embodiment. 【0008】 Hereinafter, embodiments of the non-aqueous electrolyte secondary battery according to this disclosure will be described in detail with reference to the drawings. The non-aqueous electrolyte secondary 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 non-aqueous electrolyte secondary battery (lithium-ion battery) using a non-aqueous electrolyte, namely non-aqueous electrolyte secondary battery 10, will be given as an example, but the non-aqueous electrolyte secondary battery of this disclosure is not limited to this. 【0009】 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, for the sake of explanation, the side of the non-aqueous electrolyte secondary battery 10 with the sealing body 17 in the axial direction (height direction) is referred to as "upper," and the side of the outer casing 16a in the axial direction is referred to as "lower." Furthermore, 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. 【0010】 Figure 1 is an axial cross-sectional view of a non-aqueous electrolyte secondary battery, which is an example of an embodiment. Figure 2 is a cross-sectional view of the electrode in an unfolded state, which is an example of an embodiment. As shown in Figure 1, the non-aqueous electrolyte secondary battery 10 comprises an electrode body 14, a non-aqueous electrolyte (not shown), and a bottomed cylindrical outer container 16 that houses the electrode body 14 and the non-aqueous electrolyte. The electrode body 14 has a positive electrode 11, a negative electrode 12, and a separator 13, and has a structure in which the positive electrode 11 and the negative electrode 12 are wound in a spiral shape via the separator 13. The outer container 16 is a bottomed cylindrical metal container with one side open in the axial direction, and the opening of the outer container 16 is sealed by a sealing body 17. 【0011】Non-aqueous electrolytes may be liquid electrolytes (electrolytes) or solid electrolytes. Liquid electrolytes include 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 solvents (e.g., fluoroethylene carbonate) in which at least some of the hydrogen atoms of these solvents are replaced with halogen atoms such as fluorine. Examples of electrolyte salts include LiPF ６ Lithium salts such as these are used. 【0012】 As the solid electrolyte, for example, a solid or gel-like polymer electrolyte, an inorganic solid electrolyte, etc., can be used. As the inorganic solid electrolyte, materials known for 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. 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. As the matrix polymer, for example, a polymer material that absorbs a non-aqueous solvent and gels is used. Examples of polymer materials include fluororesins, acrylic resins, polyether resins, etc. 【0013】 The positive electrode 11, negative electrode 12, and separator 13 constituting the electrode body 14 are all elongated strips that are wound in a spiral shape and alternately stacked in the radial direction of the electrode body 14. The negative electrode 12 is formed to be slightly larger than the positive electrode 11 in order to prevent lithium deposition. That is, the negative electrode 12 is formed to be longer than the positive electrode 11 in both the length and width (short side) directions. The separator 13 is formed to be at least slightly larger than the positive electrode 11, and two separators are arranged so as to sandwich the positive electrode 11. The non-aqueous electrolyte secondary battery 10 includes insulating plates 18 and 19 arranged above and below the electrode body 14, respectively. 【0014】The electrode body 14 has a positive electrode lead 20 connected to the positive electrode 11 by welding or the like, and a negative electrode lead 21 connected to the negative electrode 12 by welding or the like. In this embodiment, the positive electrode lead 20 is connected to the longitudinal center of the positive electrode 11 and is connected to the lower surface of the internal terminal plate 23, which is the bottom plate of the sealing body 17. One end of the negative electrode lead 21 is joined to the starting end of the winding of the negative electrode 12, and the other end is joined to the outer can 16, electrically connecting the starting end on the winding side to the inner surface of the bottom 16a of the outer can 16. In this embodiment, the sealing body 17 becomes the positive electrode external terminal, and the outer can 16 becomes the negative electrode external terminal. The current collection structure of the positive electrode 11 is not particularly limited, and multiple positive electrode leads 20 may be connected to the positive electrode 11. 【0015】 As shown in Figure 2, the positive electrode 11 has a positive electrode core 30 and a positive electrode mixture layer 31 disposed on the positive electrode core 30. The positive electrode core 30 can be made of a metal foil that is stable in the potential range of the positive electrode 11, such as aluminum, aluminum alloy, stainless steel, or titanium, or a film having a surface layer made of these metals. The thickness of the positive electrode core 30 is preferably 5 μm or more and 25 μm or less, and more preferably 10 μm or more and 20 μm or less. The positive electrode mixture layer 31 contains a positive electrode active material, a conductive agent, and a binder, and is preferably provided on both sides of the positive electrode core 30. The thickness of the positive electrode mixture layer 31 is greater than the thickness of the positive electrode core 30, for example, 60 μm or more and 120 μm or less on one side of the positive electrode core 30. 【0016】 The positive electrode active material is a lithium transition metal composite oxide containing transition metal elements such as Ni, Co, and Mn. Examples of metal elements contained in the lithium transition metal composite oxide include Ni, Co, Mn, Al, Be, B, Na, Mg, Si, K, Ca, Sc, Ti, V, Cr, Fe, Cu, Zn, Ga, Sr, Y, Zr, Nb, Mo, In, Sn, Sb, Ba, Ta, W, Pb, and Bi. Among these, it is preferable to contain at least one of Ni, Co, and Mn. The lithium transition metal composite oxide may be used alone or in combination of multiple types. 【0017】Examples of conductive agents included in the positive electrode mixture layer include carbon black such as acetylene black and Ketjenblack, graphite, carbon nanotubes (CNTs), carbon nanofibers, graphene, metal fibers, metal powders, and conductive whiskers. Examples of binders include fluororesins such as polytetrafluoroethylene (PTFE) and polyvinylidene fluoride (PVDF), olefin resins such as polyethylene, polypropylene, ethylene-propylene-isoprene copolymer and ethylene-propylene-butadiene copolymer, and acrylic resins such as polyacrylonitrile (PAN), polyimide, polyamide, and ethylene-acrylic acid copolymer. In addition, these resins may be used in combination with carboxymethylcellulose (CMC) or its salts, polyethylene oxide (PEO), etc. 【0018】 The positive electrode 11 can be manufactured by applying a positive electrode mixture slurry containing a positive electrode active material, a conductive agent, and a binder onto a positive electrode core 30, drying the coating, and then compressing it to form a positive electrode mixture layer 31 on both sides of the positive electrode core 30. A positive electrode 11 in which the core exposed portion to which the positive electrode lead 20 is connected is provided in the longitudinal center can be manufactured by intermittently applying the positive electrode mixture slurry and pausing the slurry application midway, so that the portion not coated with slurry becomes the core exposed portion. For example, N-methyl-2-pyrrolidone (NMP) can be used as the dispersion medium for the positive electrode mixture slurry. 【0019】 The negative electrode 12 comprises a negative electrode core 40 and a negative electrode mixture layer 41 disposed on the negative electrode core 40. The negative electrode core 40 can be made of a metal foil that is stable in the potential range of the negative electrode 12, such as copper, copper alloy, stainless steel, nickel, or nickel alloy, or a film having a surface layer made of these metals. The negative electrode mixture layer 41 contains a negative electrode active material and a binder, and is preferably provided on both sides of the negative electrode core 40. The negative electrode 12 can be manufactured in the same way as the positive electrode 11 by applying a negative electrode mixture slurry onto the negative electrode core 40, drying the coating, and then compressing it to form the negative electrode mixture layer 41 on both sides of the negative electrode core 40. A negative electrode lead 21 is joined to the starting end of the winding of the negative electrode 12, and protective tape 15 is attached to protect the negative electrode lead 21. 【0020】The thickness of the negative electrode 12 is, for example, 90 μm to 210 μm. In this embodiment, the thickness of the negative electrode 12 is substantially constant, except for the exposed portion of the negative electrode core described later. The thickness of the negative electrode core 40 is, for example, 5 μm to 15 μm. The thickness of the negative electrode mixture layer 41 is, for example, 40 μm to 110 μm on one side of the negative electrode core 40. 【0021】 The negative electrode active material is not particularly limited as long as it can reversibly intercept and release lithium ions, and generally, carbon materials such as graphite are used. Alternatively, elements that alloy with Li, such as Si and Sn, or materials containing these elements may be used as the negative electrode active material. Among these, silicon-containing materials containing Si are preferred. Furthermore, lithium titanate, which has a higher charge-discharge potential than carbon materials, can also be used as the negative electrode active material. The negative electrode active material may be used alone or in combination of multiple types. 【0022】 The binder contained in the negative electrode mixture layer 41 may be a fluororesin, olefin resin, PAN, polyimide, polyamide, acrylic resin, etc., as in the case of the positive electrode 11, but polyvinyl acetate, styrene-butadiene rubber (SBR), etc. may also be used. Among these, the use of SBR is preferred. One type of binder may be used alone, or multiple types may be used in combination. Furthermore, the negative electrode mixture layer 41 preferably contains CMC or a salt thereof, polyacrylic acid (PAA) or a salt thereof, polyvinyl alcohol (PVA), etc. The negative electrode mixture layer 41 may also contain a conductive agent such as CNT. 【0023】 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. Suitable materials for the separator 13 include polyethylene, polyolefins such as polypropylene, and cellulose. The separator 13 may have a single-layer structure or a multi-layer structure. A heat-resistant resin layer, such as aramid resin, may be formed on the surface of the separator 13. A filler layer containing an inorganic filler may be formed at the interface between the separator 13 and at least one of the positive electrode 11 and the negative electrode 12. 【0024】 The outer casing 16 is a bottomed cylindrical metal container with one side open in the axial direction. A gasket 28 is provided between the outer casing 16 and the sealing body 17 to ensure airtightness inside the battery and insulation between the outer casing 16 and the sealing body 17. The outer casing 16 has a grooved portion 22 formed on a part of its side surface that protrudes inward. The grooved portion 22 is preferably formed in an annular shape along the circumferential direction of the outer casing 16, and its upper surface supports the sealing body 17. The sealing body 17 is fixed to the upper part of the outer casing 16 by the grooved portion 22 and the open end of the outer casing 16 which is crimped to the sealing body 17. 【0025】 The sealing body 17 has a structure in which an internal terminal plate 23, a lower valve body 24, an insulating member 25, an upper valve body 26, and a cap 27 are stacked in order from the electrode body 14 side. Each component constituting the sealing body 17 has, for example, a disc shape or a ring shape, and each component except the insulating member 25 is electrically connected to one another. The lower valve body 24 and the upper valve body 26 are connected at their respective centers, with the insulating member 25 interposed between their respective peripheral edges. When a malfunction occurs in the battery and the internal pressure rises, the lower valve body 24 deforms and breaks, pushing the upper valve body 26 upward towards the cap 27, thereby interrupting the current path between the lower valve body 24 and the upper valve body 26. If the internal pressure rises further, the upper valve body 26 breaks, and gas is discharged from the opening of the cap 27. 【0026】 Next, the adhesive tape 60 attached to the electrode body 14 and the negative electrode 12 in the non-aqueous electrolyte secondary battery 10 of this disclosure will be described in detail with reference to Figure 3. Figure 3 is a radial cross-sectional view of an electrode, which is an example of an embodiment. 【0027】As shown in Figure 3, in this embodiment, the electrode body 14 is formed such that the longitudinal length of the negative electrode 12 is longer than that of the positive electrode 11 at the winding start side. In other words, the negative electrode 12 has an unfacing portion that does not face the positive electrode 11. The positive electrode 11 constituting the electrode body 14 has a starting end 50 on the outside of the winding of the negative electrode 12, and the negative electrode 12 and separator 13 are wound before the positive electrode 11. When the electrodes expand and contract due to charging and discharging, the portion of the negative electrode 12 facing the starting end 50 of the positive electrode 11, i.e., the portion A which overlaps in the radial direction, receives localized pressure from the starting end 50 of the positive electrode 11, causing the negative electrode 12 to deform. Deformation of the electrode plate is undesirable because it reduces battery performance. 【0028】 In this embodiment, by attaching adhesive tape 60 to the back surface of position A on the inner surface of the negative electrode 12, which faces the starting end 50 of the positive electrode 11, the rigidity of the negative electrode 12 in the center of the electrode body 14 can be improved and deformation of the negative electrode 12 can be suppressed. The reason why the adhesive tape 60 is attached to the back surface of A is that this position is a part in which the negative electrode 12 does not face the positive electrode 11 via the separator 13 and does not contribute to the electrode reaction, so attaching adhesive tape 60 to this position does not affect the battery performance. 【0029】 The adhesive tape 60 is, for example, an adhesive tape having a base layer and an adhesive layer formed on one surface of the base layer. A heat-resistant layer containing inorganic particles such as metal oxides may be provided between the base layer and the adhesive layer. The base layer can be any insulating resin, such as PPS (polyphenylene sulfide), PEEK (polyether ether ketone), PI (polyimide), PP (polypropylene), PET (polyethylene terephthalate), PBT (polybutylene terephthalate), etc. The thickness of the base layer is, for example, 5 μm to 50 μm, preferably 10 μm to 30 μm. If the base layer has the above thickness, it will have sufficient rigidity as a base layer. 【0030】The adhesive layer is the portion for adhering the adhesive tape 60 to the negative electrode 12. The thickness of the adhesive layer is, for example, 1 μm to 30 μm, preferably 5 μm to 25 μm. The adhesive portion may contain at least one of a rubber-based polymer and an acrylic-based polymer. Since the rubber-based polymer and the acrylic-based polymer are adhesive, they can adhere the adhesive tape 60 to the negative electrode 12. The adhesive layer may further contain, for example, a silicone-based polymer. 【0031】 The adhesive tape 60 is applied to the inner surface of the negative electrode 12 between the starting end 70 of the negative electrode 12 and the position facing the starting end 50 of the positive electrode 11. Specifically, the starting end 60a of the adhesive tape 60 is, for example, located on the inner surface of the negative electrode 12, closer to the end of the winding than the starting end 70 of the negative electrode 12, and closer to the beginning of the winding than position A. The ending end 60b of the adhesive tape 60 is, for example, located closer to the end of the winding than position A, and closer to the beginning of the winding than position B, which faces the starting end 50 of the positive electrode 11, on the inner surface of the negative electrode 12. When the adhesive tape 60 is applied within the above range, deformation of the negative electrode 12 can be suppressed without causing a decrease in battery response. 【0032】 The length of the negative electrode 12 of the adhesive tape 60 in the longitudinal direction is not particularly limited, but for example, it is 5 mm or more. In this case, the rigidity of the portion of the negative electrode 12 that receives pressure from the starting end 50 of the positive electrode 11, that is, the portion corresponding to position A facing the starting end 50 of the positive electrode 11, can be improved, and deformation of the negative electrode 12 can be suppressed. 【0033】 The length of the adhesive tape 60 in the short-side direction of the negative electrode 12 is, for example, 30% or more and less than 100% of the width of the negative electrode 12. It is preferable that the adhesive tape 60 is applied so that the widthwise center of the negative electrode 12 and the widthwise center of the adhesive tape 60 overlap. When the negative electrode 12 is subjected to pressure from the starting end 50 of the positive electrode 11, deformation is caused from the widthwise center of the negative electrode 12. Therefore, by overlapping the widthwise center of the adhesive tape 60 so as to cover the widthwise center of the negative electrode 12, the rigidity of the negative electrode 12 can be further improved. 【0034】 The present disclosure will be further illustrated below with reference to examples, but the present disclosure is not limited to these examples. 【0035】 <Examples> [Preparation of positive electrode slurry] As the positive electrode active material, the composition formula LiNi ０．９ Co ０．０４ Mn ０．０５ Al ０．０１ O ２ A composite oxide represented by [formula] was used. A positive electrode slurry containing the positive electrode active material, conductive agent, and binder was obtained by adding 100 (mass ratio) of positive electrode active material, 0.80 (mass ratio) of AB as a conductive agent, and 0.82 (mass ratio) of polyvinylidene fluoride (PVdF) as a binder to a liquid component (NMP) and kneading the mixture. 【0036】 [Preparation of the positive electrode] The above positive electrode slurry was applied to both sides of a positive electrode core made of aluminum foil. After drying and compressing the coating, the positive electrode core was cut to a predetermined electrode size to obtain a positive electrode in which a positive electrode mixture layer was formed on both sides of the positive electrode core. At this time, a positive electrode core exposed portion was provided at the longitudinal center of the positive electrode, with a length of 20 mm (33% of the electrode plate width) in the width direction from one end of the positive electrode core in the width direction, where the core surface was exposed. The width (electrode plate width) of the positive electrode core (positive electrode) after cutting was 60 mm. 【0037】 [Fabrication of the negative electrode] A mixture of graphite and a Si-containing material in a mass ratio of 95:5 was used as the negative electrode active material. The negative electrode active material, styrene-butadiene rubber (SBR) dispersion, and carboxymethylcellulose sodium salt (CMC-Na) were mixed in a solid content mass ratio of 98:1:1, and a negative electrode slurry was prepared using water as the dispersion medium. Next, the negative electrode slurry was applied to both sides of the negative electrode core, which was made of copper foil at the starting end of the negative electrode, leaving a predetermined exposed area. After drying and compressing the coating, the negative electrode core was cut to a predetermined electrode size to obtain a negative electrode in which a negative electrode mixture layer was formed on both sides of the negative electrode core. 【0038】 [Application of Adhesive Tape] A 30 μm thick adhesive tape with a PP base material as the main component was used in a length of 20 mm. The adhesive tape was applied to the back surface of the negative electrode at the position opposite the starting end of the positive electrode via a separator, specifically at the point where the widthwise center of the negative electrode and the widthwise center of the adhesive tape overlapped. The width of the adhesive tape was 70% of the width of the negative electrode. 【0039】[Preparation of Non-aqueous Electrolyte] Ethylene carbonate and ethyl methyl carbonate were mixed in a volume ratio of 3:7 (25 °C). LiPF ６ was dissolved therein at a concentration of 1.2 mol / L to obtain a non-aqueous electrolyte. 【0040】 [Fabrication of Cylindrical Battery] The above positive electrode with an aluminum tab welded to the exposed part and an insulating tape affixed, and the above negative electrode with a nickel tab welded to the exposed part and an insulating tape affixed were wound in a spiral shape through a separator to fabricate a wound electrode body. This electrode body was housed in a bottomed cylindrical exterior can, and after injecting the above non-aqueous electrolyte, the opening of the exterior can was sealed with a sealing body through a gasket to obtain a cylindrical battery X. 【0041】 <Comparative Example> A cylindrical battery Y was fabricated in the same manner as in the Example, except that an adhesive tape was not affixed to the negative electrode. 【0042】 <Reference Example> A cylindrical battery R was fabricated in the same manner as in the Example, except that the width of the adhesive tape affixed to the negative electrode was 20% of the width of the negative electrode. 【0043】 [Evaluation of Deformation of Negative Electrode] For each fabricated battery, constant current charging at 0.3 C was performed in an environment at 45 °C until it reached 4.2 V, and then constant voltage charging was performed at 4.2 V until the current value reached 0.02 C. Thereafter, discharging was performed at a constant current of 0.5 C until the battery voltage reached 2.85 V. After repeating this charge-discharge cycle 300 times, for each battery, cross-sectional observation was performed on a cross-section orthogonal to the winding axis direction of the electrode body using an X-ray CT device to confirm the presence or absence of deformation of the negative electrode near the starting end of the positive electrode. For batteries in which no deformation of the negative electrode was confirmed, the charge-discharge cycle was repeated 500 times and / or 1000 times, and similarly, the presence or absence of deformation of the negative electrode near the starting end of the positive electrode was confirmed. The confirmation results are shown in Table 1. Figure 4 is a front view of the starting ends of the negative electrode windings of the cylindrical batteries X, Y, and R. 【0044】 【0045】As shown in Figure 4 and Table 1, neither the battery X in the example nor the battery R in the reference example showed any deformation of the negative electrode after 300 cycles. In contrast, the battery Y in the comparative example showed deformation of the negative electrode because adhesive tape was not applied to the negative electrode. 【0046】 In the example, no deformation of the negative electrode was observed in battery X after 500 cycles and even after 1000 cycles. In contrast, in the reference example, battery R showed deformation of the negative electrode after 500 cycles because the width of the adhesive tape attached to the negative electrode was 20% of the width of the negative electrode. 【0047】 From the above results, it can be seen that deformation of the negative electrode can be prevented by attaching adhesive tape of a predetermined width to the back surface of the position opposite the starting end of the positive electrode via a separator, as in the example. 【0048】 The above embodiments can be modified as appropriate without impairing the purpose of this disclosure. In the above embodiments, a case in which a safety valve is provided at the upper end of the sealing body 17 has been described. However, a cap including a projection that protrudes axially upward from the radial center may be provided at the upper end of the sealing body. 【0049】 The non-aqueous electrolyte secondary battery of this disclosure may have the following configurations: Configuration 1: A non-aqueous electrolyte secondary battery comprising an electrode body in which a positive electrode and a negative electrode are wound with a separator between them, and a bottomed cylindrical outer casing that houses the electrode body, wherein the positive electrode has a starting end on the outer side of the winding of the negative electrode, the negative electrode has a negative electrode lead with one end joined to the starting end side of the negative electrode and the other end joined to the outer casing, and the negative electrode has adhesive tape attached to the back surface of the negative electrode at a position opposite to the starting end of the positive electrode. Configuration 2: The non-aqueous electrolyte secondary battery according to Configuration 1, wherein the adhesive tape is attached between the starting end of the negative electrode and the position opposite to the starting end of the positive electrode. Configuration 3: The non-aqueous electrolyte secondary battery according to Configuration 1 or 2, wherein the length of the adhesive tape in the longitudinal direction of the negative electrode is 5 mm or more, and the length of the adhesive tape in the short direction of the negative electrode is 30% or more and less than 100% of the width of the negative electrode. 【0050】10 Non-aqueous electrolyte secondary battery, 11 Positive electrode, 12 Negative electrode, 13 Separator, 14 Electrode body, 16 Outer can, 17 Sealing body, 18, 19 Insulating plate, 20 Positive electrode lead, 21 Negative electrode lead, 22 Grooved section, 23 Internal terminal plate, 24 Lower valve body, 25 Insulating material, 26 Upper valve body, 27 Cap, 28 Gasket, 30 Positive electrode core, 31 Positive electrode mixture layer, 40 Negative electrode core, 41 Negative electrode mixture layer, 60 Adhesive tape

Claims

1. A non-aqueous electrolyte secondary battery comprising an electrode body in which a positive electrode and a negative electrode are wound with a separator in between, and a bottomed cylindrical outer casing for housing the electrode body, wherein the positive electrode has a starting end on the outer side of the winding of the negative electrode, the negative electrode has a negative electrode lead with one end joined to the starting end side of the negative electrode and the other end joined to the outer casing, and adhesive tape is attached to the back surface of the negative electrode at a position opposite to the starting end of the positive electrode.

2. The non-aqueous electrolyte secondary battery according to claim 1, wherein the adhesive tape is affixed between the starting end of the negative electrode and a position opposite the starting end of the positive electrode.

3. The non-aqueous electrolyte secondary battery according to claim 1, wherein the adhesive tape has a length of 5 mm or more in the longitudinal direction of the negative electrode, and its length in the short direction of the negative electrode is 30% or more but less than 100% of the width of the negative electrode.

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