Secondary battery

Abstract

Wound positive-electrode core body exposed parts are bundled and connected to a positive-electrode collector body. A tape is affixed straddling a separator positioned on the outermost surface of a winding electrode body, and the outermost surface of the wound positive-electrode core body exposed parts. The tape has a porous base material and an adhesive layer provided on the base material. The tape has a region in which the adhesive layer b is not provided on the base material a between the connection part between the tape and the separator positioned on the outermost surface of the winding electrode body, and the connection part between the tape and the outermost surface of the wound positive-electrode core body exposed parts.

Description

[Technical field]

[0001] The present disclosure relates to secondary batteries. [Background technology]

[0002] 2. Description of the Related Art Secondary batteries, such as alkaline secondary batteries and non-aqueous electrolyte secondary batteries, are used in stationary storage battery systems, etc., for purposes such as power sources for driving electric vehicles (EVs) and hybrid electric vehicles (HEVs, PHEVs), for suppressing output fluctuations in solar power generation, wind power generation, etc., and for peak shifting of grid power by storing electricity at night for use during the day.

[0003] The secondary battery may be contaminated with foreign matter during assembly, and may cause an internal short circuit, especially if the contaminated foreign matter is a conductive foreign matter such as a metallic foreign matter. For example, when a metallic foreign matter adheres to the positive electrode plate, the metallic foreign matter dissolves as metal ions in the electrolyte due to the high potential of the positive electrode plate, and when the metal ions reach the negative electrode plate, they precipitate as metal. Then, the metal precipitates so as to grow toward the positive electrode plate, and when the metal breaks through the separator and comes into contact with the positive electrode plate, an internal short circuit occurs. It is also possible that the contaminated metallic foreign matter breaks through the separator directly, causing an internal short circuit.

[0004] Patent Document 1 proposes a secondary battery in which an insulating member covers the positive electrode exposed portion or the negative electrode exposed portion as well as the end of the separator adjacent to the outer periphery of the positive electrode exposed portion or the negative electrode exposed portion, with the aim of preventing an internal short circuit caused by the inclusion of foreign matter. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2012-49073 A Summary of the Invention

[0006] A secondary battery according to an embodiment of the present disclosure includes: A first electrode plate having a first electrode active material layer formed on a first electrode core; a second electrode plate having a second electrode active material layer formed on a second electrode core; A secondary battery having a flat wound electrode body in which the first electrode plate and the second electrode plate are wound with a separator interposed therebetween, the wound electrode body has a first electrode core exposed portion wound around one end in a direction in which a winding axis of the wound electrode body extends, and a second electrode core exposed portion wound around the other end in the direction in which the winding axis extends, the wound first electrode core exposed portion is bundled and connected to a first electrode current collector, A separator is disposed on the outermost surface of the wound electrode body, a tape is affixed across a separator disposed on the outermost surface of the wound electrode body and an outermost surface of the wound first electrode core exposed portion; The tape has a porous substrate and an adhesive layer provided on the substrate, The tape has an area where the adhesive layer is not provided on the substrate between the adhesive portion between the tape and a separator arranged on the outermost surface of the wound electrode body and the adhesive portion between the tape and the outermost surface of the wound first electrode core exposed portion.

[0007] According to the configuration of the secondary battery of the embodiment of the present disclosure, the tape is attached across the separator arranged on the outermost surface of the wound electrode body and the outermost surface of the wound first electrode core exposed portion, so that it is possible to suppress the intrusion of foreign matter into the wound electrode body from between the separator located on the outermost surface of the wound electrode body and the wound first electrode core exposed portion. In addition, the base material of the tape is porous, and a region where no adhesive layer is provided on the base material is formed between the adhesive portion between the tape and the separator arranged on the outermost surface of the wound electrode body and the adhesive portion between the tape and the outermost surface of the wound first electrode core exposed portion, so that the intrusion of the electrolyte into the wound electrode body is not hindered. Therefore, it is possible to suppress the occurrence of a portion where the electrolyte is insufficient in the wound electrode body. Note that if a portion where the electrolyte is insufficient occurs in the wound electrode body, problems such as a decrease in battery characteristics or lithium precipitation may occur.

[0008] The porous substrate is preferably a nonwoven fabric.

[0009] The weight of the nonwoven fabric is 40 to 100 g / m 2 and The average fiber diameter of the fibers constituting the nonwoven fabric is preferably 8 to 60 μm.

[0010] It is preferable that the first electrode plate is a positive electrode plate and the second electrode plate is a negative electrode plate.

[0011] According to one embodiment of the present disclosure, the intrusion of an electrolyte into the wound electrode body is not hindered, and the intrusion of metallic foreign matter into the wound electrode body is suppressed. [Brief description of the drawings]

[0012] [Figure 1] FIG. 1 is a front view showing the inside of a secondary battery according to an embodiment, with the front portion of a battery case and the front portion of an insulating sheet removed. [Diagram 2] FIG. 2 is a top view of the secondary battery according to the embodiment. [Figure 3A] FIG. 3A is a plan view of a positive electrode plate according to an embodiment. [Figure 3B] FIG. 3B is a plan view of the negative electrode plate according to the embodiment. [Figure 4] FIG. 4 is a diagram showing a method for clamping the wound positive electrode substrate exposed portion and positive electrode current collector with a horn and an anvil when performing ultrasonic bonding in the manufacturing process of the secondary battery according to the embodiment. [Diagram 5] FIG. 5 is a cross-sectional view of the vicinity of the outermost periphery of the wound positive electrode core exposed portion of the wound electrode body according to the embodiment, and is a cross-sectional view in a direction along the winding axis of the wound electrode body. [Figure 6] FIG. 6 is a plan view of the tape according to the embodiment. [Figure 7A] FIG. 7A is a plan view of a flat wound electrode body according to an embodiment. [Figure 7B] FIG. 7B is a side view of a flat wound electrode body according to the embodiment. [Figure 8] FIG. 8 is a cross-sectional view of the vicinity of the outermost periphery of a wound positive electrode core exposed portion of a wound electrode body according to another embodiment, and is a cross-sectional view in a direction along the winding axis of the wound electrode body. [Figure 9] FIG. 9 is a cross-sectional view of the vicinity of the outermost periphery of the wound positive electrode core exposed portion of the wound electrode body with no tape attached, and is a cross-sectional view in a direction along the winding axis of the wound electrode body. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] A secondary battery according to an embodiment of the present disclosure will be described with reference to the drawings. Note that the scope of the present invention is not limited to the following embodiment, and can be arbitrarily modified within the scope of the technical concept of the present invention.

[0014] First, the configuration of a prismatic secondary battery as a secondary battery according to one embodiment will be described.

[0015] As shown in FIG. 1 and FIG. 2, a prismatic secondary battery 100 includes a prismatic exterior body 1 having an opening at the top, and a sealing plate 2 that seals the opening. The prismatic exterior body 1 and the sealing plate 2 form a battery case 200. The prismatic exterior body 1 and the sealing plate 2 are each made of metal, and can be made of aluminum or an aluminum alloy, for example. A flat wound electrode body 3 in which a strip-shaped positive electrode plate and a strip-shaped negative electrode plate are wound with a strip-shaped separator sandwiched therebetween is accommodated in the prismatic exterior body 1 together with a non-aqueous electrolyte. The positive electrode plate is a positive electrode active material layer containing a positive electrode active material formed on a metal positive electrode core. The positive electrode plate has a positive electrode core exposed portion where the positive electrode core is exposed along the longitudinal direction. The negative electrode plate is a negative electrode active material layer containing a negative electrode active material formed on a metal negative electrode core. The negative electrode plate has a negative electrode core exposed portion where the negative electrode core is exposed along the longitudinal direction. The positive electrode core may be made of, for example, aluminum or an aluminum alloy, and the negative electrode core may be made of, for example, copper or a copper alloy.

[0016] In the wound electrode body 3, a positive electrode core exposed portion 4c, which is a positive electrode core on which no positive electrode active material layer is formed, is arranged in a wound state at one end side in the direction in which the winding axis of the wound electrode body 3 extends. The positive electrode core exposed portion 4c is wound without a separator or a negative electrode plate interposed therebetween, thereby resulting in a laminated state. A positive electrode current collector 6 is connected to the wound positive electrode core exposed portion 4c. The positive electrode current collector 6 can be made of, for example, aluminum or an aluminum alloy.

[0017] In the wound electrode body 3, a negative electrode core exposed portion 5c, which is a negative electrode core on which no negative electrode active material layer is formed, is arranged in a wound state on the other end side in the direction in which the winding axis of the wound electrode body 3 extends. The negative electrode core exposed portion 5c is wound without a separator or a positive electrode plate interposed therebetween, thereby resulting in a laminated state. A negative electrode current collector 8 is connected to the wound negative electrode core exposed portion 5c. The negative electrode current collector 8 can be made of, for example, copper or a copper alloy.

[0018] A tape 30 is attached across the separator 20 located on the outermost surface of the wound electrode body 3 and the outermost surface of the wound positive electrode core exposed portion 4c.

[0019] The positive electrode terminal 7 has a flange portion 7a arranged on the outer side of the sealing plate 2 facing the battery, and an insertion portion inserted into a through hole provided in the sealing plate 2. The positive electrode terminal 7 is made of metal, and can be made of, for example, aluminum or an aluminum alloy. The negative electrode terminal 9 has a flange portion 9a arranged on the outer side of the sealing plate 2 facing the battery, and an insertion portion inserted into a through hole provided in the sealing plate 2. The negative electrode terminal 9 is made of metal, and can be made of, for example, copper or a copper alloy. The negative electrode terminal 9 may have a part made of aluminum or an aluminum alloy and a part made of copper or a copper alloy. In this case, it is preferable that the part made of aluminum or an aluminum alloy protrudes outward from the sealing plate 2, and the part made of copper or a copper alloy is connected to the negative electrode current collector 8.

[0020] The positive electrode current collector 6 is fixed to the sealing plate 2 with a resin inner insulating member 10 sandwiched therebetween, and the positive electrode terminal 7 is fixed to the sealing plate 2 with a resin outer insulating member 11 sandwiched therebetween. The negative electrode current collector 8 is fixed to the sealing plate 2 with a resin inner insulating member 12 sandwiched therebetween, and the negative electrode terminal 9 is fixed to the sealing plate 2 with a resin outer insulating member 13 sandwiched therebetween.

[0021] The wound electrode body 3 is contained within the rectangular exterior body 1 while being covered with an insulating sheet 14. The sealing plate 2 is welded to the edge of the opening of the rectangular exterior body 1 by laser welding or the like. The sealing plate 2 has an electrolyte injection hole 16, which is sealed with a sealing plug 17 after the electrolyte is injected into the rectangular exterior body 1. The sealing plate 2 is formed with a gas exhaust valve 15 for exhausting gas when the pressure inside the battery case 200 reaches or exceeds a predetermined value.

[0022] The details of each component will be described below.

[0023] [Positive plate] First, a method for manufacturing the positive electrode plate will be described.

[0024] [Preparation of positive electrode active material layer slurry] A lithium nickel cobalt manganese composite oxide as a positive electrode active material, polyvinylidene fluoride (PVdF) as a binder, a carbon material as a conductive material, and N-methyl-2-pyrrolidone (NMP) as a dispersion medium are mixed and kneaded so that the mass ratio of lithium nickel cobalt manganese composite oxide:PVdF:carbon material is 97.5:1:1.5 to prepare a positive electrode active material layer slurry.

[0025] [Formation of positive electrode active material layer] The positive electrode active material layer slurry prepared by the above method is applied to both sides of an aluminum foil having a thickness of 15 μm as a positive electrode core by a die coater. The positive electrode core to which the positive electrode active material layer slurry is applied is dried to remove the NMP in the slurry. This forms a positive electrode active material layer. Then, the positive electrode active material layer is compressed by a pair of press rollers to form a positive electrode original plate. This positive electrode original plate is cut to a predetermined size.

[0026] 3A is a plan view of the positive electrode plate 4. Positive electrode active material layers 4b are formed on both sides of the positive electrode core 4a. A positive electrode core exposed portion 4c where the positive electrode core 4a is exposed along the longitudinal direction of the positive electrode plate 4 is provided at one end in the width direction of the positive electrode plate 4.

[0027] [Negative plate] Next, a method for manufacturing the negative electrode plate will be described.

[0028] [Preparation of negative electrode active material layer slurry] Graphite as the negative electrode active material, styrene butadiene rubber (SBR) and carboxymethyl cellulose (CMC) as binders, and water as a dispersion medium are kneaded together so that the mass ratio of graphite:SBR:CMC is 98:1:1 to prepare a negative electrode active material layer slurry.

[0029] [Formation of negative electrode active material layer] The negative electrode active material layer slurry prepared by the above method is applied to both sides of a copper foil having a thickness of 8 μm as a negative electrode core by a die coater. The negative electrode core to which the negative electrode active material layer slurry is applied is dried to remove water in the slurry. This forms a negative electrode active material layer. Then, the negative electrode active material layer is compressed by a pair of press rollers to form a negative electrode original plate. This negative electrode original plate is cut to a predetermined size.

[0030] 3B is a plan view of the negative electrode plate 5. Negative electrode active material layers 5b are formed on both sides of the negative electrode core 5a. A negative electrode core exposed portion 5c where the negative electrode core 5a is exposed along the longitudinal direction of the negative electrode plate 5 is provided at one end in the width direction of the negative electrode plate 5.

[0031] [Preparation of wound electrode body] The positive electrode plate 4 and the negative electrode plate 5 obtained by the above-mentioned method are wound with a separator 20 made of, for example, polyethylene interposed therebetween, and formed into a flat shape. This results in a flat wound electrode body 3 having a wound positive electrode core exposed portion 4c at one end and a wound negative electrode core exposed portion 5c at the other end.

[0032] [Installing parts on the sealing plate] Hereinafter, a method for attaching the positive electrode current collector 6, the positive electrode terminal 7, the negative electrode current collector 8, and the negative electrode terminal 9 to the sealing plate 2 will be described.

[0033] First, the external insulating member 11 is disposed on the battery external side of the sealing plate 2, and the internal insulating member 10 and the positive electrode current collector 6 are disposed on the battery internal side of the sealing plate 2. Next, the insertion portion of the positive electrode terminal 7 is inserted from the battery external side into the through holes provided in the external insulating member 11, the sealing plate 2, the internal insulating member 10, and the positive electrode current collector 6, respectively, and the tip side of the insertion portion of the positive electrode terminal 7 is crimped onto the positive electrode current collector 6. As a result, the positive electrode terminal 7, the external insulating member 11, the sealing plate 2, the internal insulating member 10, and the positive electrode current collector 6 are fixed integrally. It is preferable to weld the crimped portion of the tip of the insertion portion of the positive electrode terminal 7 to the positive electrode current collector 6.

[0034] Similarly, the external insulating member 13 is disposed on the battery external side of the sealing plate 2, and the internal insulating member 12 and the negative electrode current collector 8 are disposed on the battery internal side of the sealing plate 2. Next, the insertion portion of the negative electrode terminal 9 is inserted from the battery external side into the through holes provided in the external insulating member 13, the sealing plate 2, the internal insulating member 12, and the negative electrode current collector 8, respectively, and the tip side of the insertion portion of the negative electrode terminal 9 is crimped onto the negative electrode current collector 8. As a result, the negative electrode terminal 9, the external insulating member 13, the sealing plate 2, the internal insulating member 12, and the negative electrode current collector 8 are fixed integrally. It is preferable to weld the crimped portion of the tip of the insertion portion of the negative electrode terminal 9 to the negative electrode current collector 8.

[0035] [Attaching the current collector to the wound electrode body] A positive electrode current collector 6 is placed on the outer surface of the positive electrode core exposed portion 4c that has been laminated by winding. As shown in FIG. 4, the laminated positive electrode core exposed portion 4c and the positive electrode current collector 6 are sandwiched between a horn 90 and an anvil 91 of an ultrasonic bonding device and ultrasonic bonding is performed. This connects the wound positive electrode core exposed portion 4c and the positive electrode current collector 6. The negative electrode core exposed portion 5c and the negative electrode current collector 8 that have been laminated by winding can also be connected in a similar manner. The connection method is not limited to ultrasonic bonding, and resistance welding or laser welding may also be used.

[0036] [Structure of wound electrode body] Fig. 9 is a cross-sectional view of the vicinity of the outermost surface of the wound positive electrode core exposed portion 4c of the wound electrode body 3. Fig. 9 is also a cross-sectional view in a direction along the winding axis of the wound electrode body 3. Fig. 9 is a view showing a state in which the tape 30 is not attached to the wound electrode body 3. A separator 20 is disposed on the outermost periphery of the wound electrode body 3. In the wound electrode body 3, the layer located on the outermost side of the negative electrode plate 5 is located on the outermost side of the layer located on the outermost side of the positive electrode plate 4.

[0037] 9, the positive electrode core exposed portions 4c that have been stacked by winding are bundled and connected to the positive electrode current collector 6. In a secondary battery including the wound electrode body 3, when an electrolyte is poured into the battery case 200, foreign matter 80 may get in between the positive electrode plate 4 and the separator 20 or between the negative electrode plate 5 and the separator 20 together with the electrolyte, as shown in FIG.

[0038] Furthermore, if tape is applied from the separator 20 located at the outermost periphery of the wound electrode body 3 to the outermost surface of the positive electrode substrate exposed portion 4c in order to prevent such an internal short circuit, it is possible to prevent foreign matter from entering the wound electrode body 3. However, this makes it difficult for the electrolyte to enter the wound electrode body 3. This may result in portions of the wound electrode body 3 lacking electrolyte, which may cause uneven charge / discharge reactions or precipitation of lithium metal.

[0039] [Painting the tape] 5, tape 30 is applied from separator 20 located on the outermost surface of flat wound electrode body 3 to the outermost surface of wound positive electrode core exposed portion 4c. Tape 30 has porous base material 30a and adhesive layer 30b provided on one surface of base material 30a.

[0040] 6, two adhesive layers 30b are provided on one surface of the base material 30a along the longitudinal direction of the tape 30. The two adhesive layers 30b are provided in the width direction of the tape 30 and spaced apart from each other.

[0041] 5, a separator 20 is disposed on the outermost surface of the wound electrode body 3. In the wound electrode body 3, the layer of the negative electrode plate 5 located closest to the outermost periphery of the wound electrode body 3 is located closer to the outermost periphery of the wound electrode body 3 than the layer of the positive electrode plate 4 located closest to the outermost periphery of the wound electrode body 3.

[0042] The substrate 30a of the tape 30 is connected to the separator 20 located at the outermost periphery of the wound electrode body 3 by the adhesive layer 30b. The substrate 30a of the tape 30 is connected to the outermost surface of the wound positive electrode core exposed portion 4c by the adhesive layer 30b. Between the portion of the tape 30 connected to the separator 20 and the portion of the tape 30 connected to the positive electrode core exposed portion 4c, an area in which the adhesive layer 30b is not formed is provided on the substrate 30a. The substrate 30a is a porous member through which the electrolyte can permeate. With this configuration, the electrolyte is not inhibited from penetrating into the wound electrode body 3, and foreign matter is prevented from penetrating into the wound electrode body 3.

[0043] A nonwoven fabric is particularly preferable as the porous substrate 30a. When the substrate 30a is a nonwoven fabric, foreign matter can be effectively captured. The nonwoven fabric is preferably made of fibers made of resin such as polyester, polyolefin, polyamide, polyurethane, or polystyrene, glass fiber, ceramic fiber, or cellulose fiber.

[0044] The weight of the nonwoven fabric is 40 to 100 g / m 2 The weight of the nonwoven fabric is preferably 40 g / m 2 By setting the weight per unit area of ​​the nonwoven fabric at 100 g / m or more, it is possible to more effectively prevent foreign matter from entering the wound electrode body 3. 2 By setting the following, it is possible to provide a configuration in which the electrolyte can easily enter the wound electrode body 3.

[0045] The average fiber diameter of the fibers constituting the nonwoven fabric is preferably 8 to 60 μm. By setting the average fiber diameter of the fibers to 8 μm or more, it is possible to more effectively prevent foreign matter from entering the wound electrode body 3. Furthermore, by setting the average fiber diameter of the fibers to 60 μm or less, it is possible to achieve a configuration in which the electrolyte can easily enter the wound electrode body 3. The average fiber diameter of the fibers is the average value of the diameters at 10 arbitrary points selected on an image by SEM measurement.

[0046] If a foreign object with a diameter of 20 μm or more enters the wound electrode body 3, an internal short circuit is likely to occur. 2 By setting the average fiber diameter of the fibers constituting the nonwoven fabric to 8 μm or more, it is possible to more effectively prevent foreign matter having a diameter of 20 μm or more from entering the wound electrode body 3. Furthermore, by setting the average fiber diameter of the fibers constituting the nonwoven fabric to 8 μm or more, it is possible to more effectively prevent foreign matter having a diameter of 20 μm or more from entering the wound electrode body 3.

[0047] As the porous substrate 30a, in addition to nonwoven fabric, a porous polymer film made of polyolefin resin, fluorine resin, or the like can be used.

[0048] The adhesive layer 30b is preferably made of a material selected from the group consisting of rubber-based adhesives, acrylic-based adhesives, polyethylene-based adhesives, and the like, or a mixture thereof, but is not limited to these.

[0049] 7A and 7B, the flat wound electrode body 3 has a flat portion 3a with a substantially uniform thickness and curved portions 3b formed on both ends of the flat portion 3a. The outer surface of the curved portion 3b is curved.

[0050] The length of the flat portion 3a in the direction perpendicular to the winding axis of the wound electrode body 3 (the vertical length in Figs. 7A and 7B) is defined as length L1. In this case, the length L2 of the area of ​​the wound electrode body 3 to which the tape 30 is attached is preferably 0.5 x L1 or more, and more preferably 0.8 x L1 or more.

[0051] The tape 30 is preferably attached to both outer surfaces of the flat portion 3a of the wound electrode body 3. In this case, one tape 30 can be attached to one outer surface of the flat portion 3a, and another tape 30 can be attached to the other outer surface of the flat portion 3a. Alternatively, one tape 30 can be attached across one outer surface of the flat portion 3a, the curved portion 3b, and the other outer surface of the flat portion 3a.

[0052] In the above, an example has been described in which the positive electrode current collector 6 is connected to the positive electrode core exposed portion 4c and then the tape 30 is attached to the wound electrode body 3, but the positive electrode current collector 6 may be connected to the positive electrode core exposed portion 4c after the tape 30 is attached to the wound electrode body 3.

[0053] As shown in Fig. 5, in the direction in which the winding axis of the wound electrode body 3 extends, the central end of the tape 30 is preferably disposed outside the outer end of the negative electrode plate 5. That is, when the wound electrode body 3 is viewed along the stacking direction of the positive electrode plate 4, the separator 20, and the negative electrode plate 5 in the flat portion 3a, it is preferable that the negative electrode plate 5 and the tape 30 are disposed so as not to overlap. This makes it possible to prevent the separator 20 from bending toward the center in the stacking direction (to the lower side in Fig. 5) and causing a partially thick portion to be generated in the flat portion 3a of the wound electrode body 3. The tape 30 may be disposed so as to overlap the negative electrode plate 5.

[0054] Moreover, it is preferable that one end side of the tape 30 in the width direction is connected to the inclined region in the positive electrode substrate exposed portion 4c by the adhesive layer 30b.

[0055] The width of the base material 30a may be, for example, about 5 mm to 30 mm. However, this is not limited to this. The width of the adhesive layer 30b may be, for example, about 2 mm to 10 mm. However, this is not limited to this. The width of the region of the base material 30a where no adhesive layer 30b is formed, which is provided between two adhesive layers 30b, may be, for example, about 1 mm to 25 mm. However, this is not limited to this.

[0056] The tape 30 may be placed on the outer surface of the wound positive electrode core exposed portion 4c on the side where the positive electrode current collector 6 is not placed. For example, the tape 30 can be attached to a portion of the outer surface of the wound positive electrode core exposed portion 4c that comes into contact with an anvil or a horn for ultrasonic bonding before ultrasonic bonding. Also, the tape 30 can be attached to a portion of the outer surface of the wound positive electrode core exposed portion 4c that comes into contact with an anvil or a horn for ultrasonic bonding after ultrasonic bonding.

[0057] <Other embodiments> 8, a part of the tape 30 may be attached onto the positive electrode current collector 6. With such a configuration, foreign matter attached to the positive electrode current collector 6 or burrs formed on the positive electrode current collector 6 can be held on the positive electrode current collector 6 by the tape 30.

[0058] It should be noted that the positive electrode current collector 6 may be connected to the positive electrode core exposed portion 4c after the tape 30 is attached to the separator 20 and the positive electrode core exposed portion 4c.

[0059] <Other> Known materials can be used for the positive electrode plate, the negative electrode plate, the separator, the electrolyte, and the like. [Explanation of symbols]

[0060] 100 Prismatic secondary battery 200 Battery Case 1. Rectangular exterior body 2 Sealing plate 3 Wound electrode body 3a Flat area 3b Curved part 4 Positive plate 4a Positive electrode core 4b Positive electrode active material layer 4c Positive electrode core exposed part 5 Negative plate 5a Negative electrode core 5b Negative electrode active material layer 5c Negative electrode core exposed part 6 Positive electrode current collector 7 Positive terminal 7a Tsubabe 8 Negative electrode current collector 9 Negative terminal 9a Tsubabe 10 Inner insulating member 11 External insulating member 12 Inner insulating member 13 External insulating member 14 Insulation sheet 15 Gas exhaust valve 16 Electrolyte injection hole 17 Sealing plug 20 Separator 30 Tape 30a base material 30b Adhesive layer 80 Foreign matter 90 Horn 91 Anvil

Claims

1. a first electrode plate having a first electrode active material layer formed on a first electrode core; a second electrode plate having a second electrode active material layer formed on a second electrode core; A secondary battery having a flat wound electrode body in which the first electrode plate and the second electrode plate are wound with a separator interposed therebetween, the wound electrode body has a first electrode core exposed portion wound around one end in a direction in which a winding axis of the wound electrode body extends, and a second electrode core exposed portion wound around the other end in the direction in which the winding axis extends, the wound first electrode core exposed portion is bundled and connected to a first electrode current collector, A separator is disposed on the outermost surface of the wound electrode body, a tape is affixed across a separator disposed on the outermost surface of the wound electrode body and an outermost surface of the wound first electrode core exposed portion; The tape has a porous substrate and an adhesive layer provided on the substrate, The tape is a secondary battery having an area where the adhesive layer is not provided on the substrate between an adhesive portion between the tape and a separator arranged on the outermost surface of the wound electrode body and an adhesive portion between the tape and the outermost surface of the wound first electrode core exposed portion.

2. 2. The secondary battery according to claim 1, wherein the porous substrate is a nonwoven fabric.

3. The weight of the nonwoven fabric is 40 to 100 g / m ２ and 3. The secondary battery according to claim 2, wherein the average fiber diameter of the fibers constituting the nonwoven fabric is 8 to 60 μm.

4. 4. The secondary battery according to claim 1, wherein the first electrode plate is a positive electrode plate, and the second electrode plate is a negative electrode plate.

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