Cylindrical battery

Abstract

The objective of the present disclosure is to provide a cylindrical battery in which it is possible to fix an insulating plate disposed in an upper portion between an electrode body and a sealing plate. A cylindrical battery (10) is provided with: an electrode body (14) in which a positive electrode (11) and a negative electrode (12) are wound with a separator (13) interposed therebetween; an electrolyte; a bottomed cylindrical outer can (20) accommodating the electrode body (14) and the electrolyte; a sealing plate (30) blocking an opening portion (20A) of the outer can (20); a gasket (31) disposed on a peripheral edge portion of the sealing plate (30); and an upper insulating plate (15) disposed between the electrode body (14) and the sealing plate (31). The gasket (31) is compressed in the radial direction between an edge surface of the peripheral edge portion of the sealing plate (30) and the outer can (20), and the outer can (20) includes a locking portion (20D) with which a peripheral edge portion (15B) of the upper insulating plate (15) engages.

Description

Technical Field

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

Background Art

[0002] A cylindrical battery has a bottomed cylindrical outer can and a sealing body that closes the opening of the outer can (for example, Patent Document 1). In the cylindrical battery disclosed in Patent Document 1, the outer can is caulked in the radial direction of the sealing body to compress a gasket interposed between the outer can and the sealing body. In such a horizontally caulked cylindrical battery, it is not necessary to provide a grooved portion between the gasket and the electrode body in the outer can, and the battery can be made high-capacity by increasing the volume for accommodating the electrode body.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the cylindrical battery disclosed in Patent Document 1, there is no disclosure regarding an insulating plate disposed between the electrode body and the sealing body and the fixing of the insulating plate. When the insulating plate is not fixed in the cylindrical battery, if the negative electrode plate extends due to overcharging or the like and the insulating plate is displaced or tilted, there is a risk that the negative electrode plate contacts the positive electrode lead or the negative electrode plate contacts the sealing body, resulting in an internal short circuit.

[0005] An object of the present disclosure is to provide a cylindrical battery capable of fixing an insulating plate disposed between an electrode body and a sealing body.

Means for Solving the Problems

[0006] A cylindrical battery according to one aspect of the present disclosure includes an electrode body in which a positive electrode plate and a negative electrode plate are wound with a separator interposed therebetween, an electrolyte, a bottomed cylindrical outer can that houses the electrode body and the electrolyte, a sealing plate that closes an opening of the outer can, a gasket disposed at a peripheral edge of the sealing plate, and an insulating plate disposed above the electrode body and insulating the electrode body from the sealing plate. The gasket is compressed in the radial direction between an end face of the peripheral edge of the sealing plate and the outer can, and the outer can has a locking portion with which a peripheral edge portion of the insulating plate engages.

Advantages of the Invention

[0007] According to one aspect of the present disclosure, an insulating plate disposed between the electrode body and the sealing body can be fixed. Thereby, the occurrence of an internal short circuit can be prevented.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Embodiments for Carrying Out the Invention

[0009] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. The shapes, materials, and numbers described below are examples and can be appropriately changed according to the specifications of the cylindrical battery. In the following, the same reference numerals will be given to equivalent elements in all the drawings for explanation.

[0010] A cylindrical battery 10 as an example of an embodiment will be described with reference to FIG. 1. FIG. 1 is a cross-sectional view of the cylindrical battery 10.

[0011] As shown in Fig. 1, the cylindrical battery 10 includes an electrode body 14, an electrolyte, an outer can 20 that houses the electrode body 14 and the electrolyte, and a sealing plate 30 that closes the opening 20A of the outer can 20. The electrode body 14 includes a positive electrode plate 11, a negative electrode plate 12, and a separator 13, and has a structure in which the positive electrode plate 11 and the negative electrode plate 12 are wound in a spiral shape with the separator 13 interposed therebetween. Further, the cylindrical battery 10 further includes an upper insulating plate 15 and a lower insulating plate 16 that are respectively disposed above and below the electrode body 14. Hereinafter, for convenience of explanation, the sealing plate 30 side (the opening 20A side of the outer can 20) of the cylindrical battery 10 is defined as the upper side, and the bottom side of the outer can 20 is defined as the lower side.

[0012] The positive electrode plate 11 has a positive electrode core body and a positive electrode mixture layer formed on at least one surface of the core body. For the positive electrode core body, a foil of a metal stable within the potential range of the positive electrode plate 11, such as aluminum or an aluminum alloy, or a film having such a metal disposed on the surface layer can be used. The positive electrode mixture layer includes a positive electrode active material, a conductive agent such as acetylene black, and a binder such as polyvinylidene fluoride, and is preferably formed on both surfaces of the positive electrode core body. For the positive electrode active material, for example, a lithium transition metal composite oxide is used. The positive electrode plate 11 can be manufactured by applying a positive electrode mixture slurry containing a positive electrode active material, a conductive agent, and a binder onto the positive electrode core body, drying the coating film, and then compressing the coating film to form the positive electrode mixture layer on both surfaces of the core body.

[0013] The negative electrode plate 12 has a negative electrode core body and a negative electrode mixture layer formed on at least one surface of the core body. For the negative electrode core body, a foil of a metal stable within the potential range of the negative electrode plate 12, such as copper or a copper alloy, or a film having such a metal disposed on the surface layer can be used. The negative electrode mixture layer includes 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 body. For the negative electrode active material, for example, graphite, a silicon-containing compound, or the like is used. The negative electrode plate 12 can be manufactured by applying a negative electrode mixture slurry containing a negative electrode active material and a binder onto the negative electrode core body, drying the coating film, and then compressing the coating film to form the negative electrode mixture layer on both surfaces of the core body.

[0014] For the electrolyte, for example, a non-aqueous electrolyte is used. The non-aqueous electrolyte includes a non-aqueous solvent and an electrolyte salt dissolved in the non-aqueous solvent. As the non-aqueous solvent, esters, ethers, nitriles, amides, and mixed solvents of two or more of these can be used. The non-aqueous solvent may contain a halogen-substituted product in which at least a part of the hydrogen atoms of these solvents are substituted with halogen atoms such as fluorine. Note that the non-aqueous electrolyte is not limited to a liquid electrolyte and may be a solid electrolyte. For the electrolyte salt, for example, lithium salts such as LiPF 6 are used. The type of the electrolyte is not particularly limited and may be an aqueous electrolyte.

[0015] The upper insulating plate 15 is a member disposed above the electrode body 14 to insulate the electrode body 14 from the sealing plate 30. The upper insulating plate 15 is formed in a disc shape having an opening 15A at the central portion in the radial direction and a through hole into which the positive electrode lead 17 is inserted. The diameter of the upper insulating plate 15 is larger than the inner diameter of the first cylindrical portion 20B of the outer can 20 described later and smaller than the maximum inner diameter of the locking portion 20D described later. The positive electrode lead 17 connected to the positive electrode plate 11 extends toward the sealing plate 30 through the through hole of the upper insulating plate 15. Further, the positive electrode lead 17 is connected to the bottom surface of the central portion of the sealing plate 30 by welding or the like, and the sealing plate 30 serves as a positive electrode external terminal.

[0016] The lower insulating plate 16 is disposed below the electrode body 14 to insulate the electrode body 14 from the outer can 20. The lower insulating plate 16 is formed in a disc shape having an opening formed at the central portion in the radial direction. The negative electrode lead 18 connected to the negative electrode plate 12 extends along the bottom of the outer can 20 through the outside of the lower insulating plate 16. The negative electrode lead 18 is connected to the inner surface of the bottom of the outer can 20 by welding or the like, and the outer can 20 serves as a negative electrode external terminal.

[0017] As described above, the cylindrical battery 10 includes an outer can 20 and a sealing plate 30 that closes the opening 20A of the outer can 20. The outer can 20 is a bottomed cylindrical metal container having a bottom and a cylindrical portion. The bottom is disc-shaped, and the cylindrical portion is formed in a cylindrical shape along the outer peripheral edge of the bottom. The cylindrical portion is formed above the bottom, and includes a first cylindrical portion 20B that houses the electrode body 14, a second cylindrical portion 20C that is thinner than the first cylindrical portion 20B and in which the gasket 31 is compressed and the sealing plate 30 is caulked and fixed, and a locking portion 20D that is formed between the first cylindrical portion 20B and the second cylindrical portion 20C and with which the peripheral edge portion 15B of the upper insulating plate 15 engages.

[0018] The first cylindrical portion 20B is a cylindrical portion that houses the electrode body 14. The height of the first cylindrical portion 20B is substantially the same as the height of the electrode body 14.

[0019] The second cylindrical portion 20C is a cylindrical portion in which the gasket 31 is compressed and the sealing plate 30 is caulked and fixed. The thickness of the second cylindrical portion 20C is preferably about 3 / 5 to 4 / 5 of the first cylindrical portion 20B. The second cylindrical portion 20C is caulked in the radial direction and formed with a reduced diameter compared to the first cylindrical portion 20B. Protrusions may be formed along the circumferential direction on the inner surface of the second cylindrical portion 20C. Thereby, the compressive force on the gasket 31 can be increased.

[0020] The locking portion 20D is a cylindrical portion that is formed between the first cylindrical portion 20B and the second cylindrical portion 20C and with which the peripheral edge portion 15B of the upper insulating plate 15 engages. The locking portion 20D is formed to include an inner portion of the upper end surface 20E of the first cylindrical portion 20B and an inclined portion 20F that connects the second cylindrical portion 20C and the outer portion of the upper end surface 20E of the first cylindrical portion 20B. The inclined portion 20F is formed so as to have a reduced diameter upward. The thickness of the inclined portion 20F is the same as the thickness of the second cylindrical portion 20C.

[0021] The peripheral edge portion 15B of the upper insulating plate 15 engages with the locking portion 20D, and the upper insulating plate 15 is fixed to the outer can 20. More specifically, the peripheral edge portion 15B of the upper insulating plate 15 is sandwiched and fixed between the inner peripheral side of the upper end surface 20E of the first cylindrical portion 20B and the inclined portion 20F.

[0022] According to the fixing portion 20D, the upper insulating plate 15 can be fixed. Thus, for example, when the upper insulating plate 15 is displaced and inclined, and the negative electrode plate 12 extends during repeated charge and discharge cycles, there is no risk of internal short circuit due to contact between the negative electrode plate 12 and the positive electrode lead 17 or between the negative electrode plate 12 and the sealing plate 30 at the opening 15A of the upper insulating plate 15.

[0023] The sealing plate 30 is a metal valve body and can include other members such as a terminal cap disposed on the upper surface. Normally, the central portion 30B on the inner peripheral side of the peripheral edge portion 30A of the sealing plate 30 protrudes toward the electrode body 14 side from the peripheral edge portion 30A. The bottom surface of the central portion 30B and the positive electrode plate 11 are connected via the positive electrode lead 17, and the sealing plate 30 serves as the positive electrode terminal of the cylindrical battery 10. According to the sealing plate 30, since the number of component parts is small, the costs and time required for processing and assembly can be reduced.

[0024] The gasket 31 is interposed between the opening 20A of the outer can 20 and the sealing plate 30 that seals the opening 20A. The gasket 31 is a flexible insulating member, and while insulating the sealing plate 30 which is the positive electrode terminal and the outer can 20 which is the negative electrode terminal, the sealing property inside the cylindrical battery 10 is ensured by being compressed in the radial direction of the sealing plate 30.

[0025] Using FIG. 2, the manufacturing process of the cylindrical battery 10 will be described. FIG. 2 is a schematic diagram showing a part of the manufacturing process.

[0026] In the manufacturing process of the cylindrical battery 10, first, the electrode body 14 and the bottomed cylindrical outer can 20 having the first cylindrical portion 20B and the second cylindrical portion 20C are produced by drawing a steel plate. Next, the electrode body 14 is inserted into the first cylindrical portion 20B of the outer can 20.

[0027] Next, as shown in Fig. 2(A), the upper insulating plate 15 is engaged inside the upper end surface 20E of the first cylindrical portion 20B of the outer can 20. Further, as shown in Fig. 2(B), the electrolytic solution is injected into the outer can 20, and the sealing plate 30 is inserted into the second cylindrical portion 20C of the outer can 20. Then, by caulking the second cylindrical portion 20C of the outer can 20 in the radial direction from the outside of the outer can 20, the opening 20A of the outer can 20 is sealed by the second cylindrical portion 20C via the gasket 31.

[0028] When caulking the second cylindrical portion 20C of the outer can 20 in the radial direction, the lower portion of the second cylindrical portion 20C is formed as an inclined portion 20F, and the peripheral edge portion 15B of the upper insulating plate 15 engaged with the upper end surface 20E of the outer can 20 is engaged with a locking portion 20D formed by the upper end surface 20E and the inclined portion 20F.

[0029] With reference to Fig. 3, a cylindrical battery 10 which is another example of the embodiment will be described. Fig. 3 is a cross-sectional view of the cylindrical battery 10.

[0030] As shown in Fig. 3, the cylindrical battery 10 includes an electrode body 14, an electrolyte, an outer can 40 that houses the electrode body 14 and the electrolyte, and a sealing plate 30 that closes the opening 40A of the outer can 40. Further, the cylindrical battery 10 further includes an upper insulating plate 15 and a lower insulating plate 16 that are respectively disposed above and below the electrode body 14. Since the parts other than the upper insulating plate 15 and the outer can 20 are the same as the cylindrical battery 10 described in Fig. 1, the description thereof will be omitted.

[0031] The upper insulating plate 15 is a member that is disposed above the electrode body 14 and insulates the electrode body 14 and the sealing plate 30. The upper insulating plate 15 is formed in a disc shape having an opening 15A formed in the central portion in the radial direction and a through hole. The diameter of the upper insulating plate 15 is larger than the inner diameter of the housing portion 40B of the outer can 40 described later and smaller than the maximum inner diameter of the locking portion 40D described later.

[0032] The outer can 40 is a bottomed cylindrical metal container having a bottom portion and a cylindrical portion. The bottom portion has a disc shape, and the cylindrical portion is formed cylindrically along the outer peripheral edge of the bottom portion. The cylindrical portion is formed above the bottom portion and includes a housing portion 40B that houses the electrode body 14, a caulking portion 40C where the gasket 31 is compressed and the sealing plate 30 is caulked and fixed, and a locking portion 40D formed between the housing portion 40B and the caulking portion 40C, with which the peripheral edge portion 15B of the upper insulating plate 15 engages. The thicknesses of the housing portion 40B, the locking portion 40D, and the caulking portion 40C are the same.

[0033] The housing portion 40B is a cylindrical portion that houses the electrode body 14. The height of the housing portion 40B is made substantially the same as the height of the electrode body 14.

[0034] The caulking portion 40C is a cylindrical portion where the gasket 31 is compressed and the sealing plate 30 is caulked and fixed. The caulking portion 40C is formed by caulking in the radial direction and having a reduced diameter compared to the locking portion 40D. Protrusions may be formed along the circumferential direction on the inner surface of the caulking portion 40C. Thereby, the compressive force applied to the gasket 31 can be increased.

[0035] The locking portion 40D is a portion formed between the housing portion 40B and the caulking portion 40C, with which the peripheral edge portion 15B of the upper insulating plate 15 engages. The locking portion 40D is formed to include a diameter-expanding portion 40E that expands in diameter upward from the housing portion 40B and a connecting portion 40F that connects the diameter-expanding portion 40E and the caulking portion 40C.

[0036] The peripheral edge portion 15B of the upper insulating plate 15 engages with the locking portion 40D, and the upper insulating plate 15 is fixed to the outer can 40. More specifically, the peripheral edge portion 15B of the upper insulating plate 15 is sandwiched and fixed between the diameter-expanding portion 40E and the connecting portion 40F. According to the locking portion 40D, the upper insulating plate 15 can be fixed.

[0037] The manufacturing process of the cylindrical battery 10 will be described with reference to FIG. 4. FIG. 4 is a schematic diagram showing a part of the manufacturing process.

[0038] In the manufacturing process of the cylindrical battery 10, first, an exterior can 40 having an electrode body 14, a housing portion 40B that houses the electrode body 14 by drawing a steel plate, and a diameter-expanding portion 40G (a portion corresponding to the diameter-expanding portion 40E, the connecting portion 40F, and the caulking portion 40C of the cylindrical battery 10) that expands in diameter upward is produced. Next, the electrode body 14 is inserted into the housing portion 40B of the exterior can 40.

[0039] As shown in FIG. 4(A), next, an upper insulating plate 15 is engaged in the middle of the diameter-expanding portion 40G of the exterior can 40. Further, as shown in FIG. 4(B), an electrolytic solution is injected into the exterior can 40, and a sealing plate 30 is inserted into the diameter-expanding portion 40G of the exterior can 20. Then, by caulking the diameter-expanding portion 40G of the exterior can 40 in the radial direction from the outside of the exterior can 40, the opening 40A of the exterior can 40 is sealed by the caulking portion 40C via a gasket 31.

[0040] When the caulking portion 40C of the exterior can 40 is formed, the lower portion of the caulking portion 40C is formed as the connecting portion 40F, and the peripheral edge portion 15B of the upper insulating plate 15 that was engaged in the middle of the diameter-expanding portion 40G of the exterior can 20 is engaged with a locking portion 40D formed by the diameter-expanding portion 40E and the connecting portion 40F.

[0041] Note that the present invention is not limited to the above-described embodiments and their modified examples, and it goes without saying that various changes and improvements can be made within the scope of the matters described in the claims of the present application.

Explanation of Reference Numerals

[0042] 10 Cylindrical battery, 11 Positive electrode plate, 12 Negative electrode plate, 13 Separator, 14 Electrode body, 15 Upper insulating plate, 15A Opening, 15B Peripheral edge portion, 16 Lower insulating plate, 17 Positive electrode lead, 18 Negative electrode lead, 20 Exterior can, 20A Opening, 20B First cylindrical portion, 20C Second cylindrical portion, 20D Locking portion, 20E Upper end face, 20F Inclined portion, 30 Sealing plate, 30A Peripheral edge portion, 30B Central portion, 31 Gasket, 40 Exterior can, 40A Opening, 40B Housing portion, 40C Caulking portion, 40D Locking portion, 40E Diameter-expanding portion, 40F Connecting portion, 40G Diameter-expanding portion

Claims

Claim 1 A cylindrical battery comprising: an electrode body in which a positive electrode plate and a negative electrode plate are wound with a separator interposed therebetween; an electrolyte; a bottomed cylindrical outer can that houses the electrode body and the electrolyte; a sealing plate that closes an opening of the outer can; a gasket disposed at a peripheral edge of the sealing plate; and an insulating plate disposed between the electrode body and the sealing plate, wherein the gasket is compressed in a radial direction between an end face of a peripheral edge of the sealing plate and the outer can, the outer can has a locking portion with which a peripheral edge of the insulating plate engages, the outer can has a first cylindrical portion that houses the electrode body and a second cylindrical portion that is thinner than the first cylindrical portion that compresses the gasket, the locking portion includes an upper end face of the first cylindrical portion and an inclined portion that connects the first cylindrical portion and the second cylindrical portion and has the same thickness as the second cylindrical portion, a cylindrical battery.

Images