Button-type secondary battery and secondary battery module including the same

Abstract

The present invention relates to a coin-type secondary battery in which, when an electrode assembly is installed in a lower can, an upper can is coupled to the lower can, and the coin-type secondary battery includes: the lower can including a first flat portion on which the electrode assembly is disposed, a first side wall portion formed perpendicularly along a circumference of the first flat portion, and a recess portion formed to have a shape recessed from an outer surface of the first side wall portion; and the upper can including a second flat portion capable of covering an opening upper surface of the lower can, a second side wall portion formed perpendicularly along a circumference of the second flat portion, and a convex portion formed to protrude convexly from an inner surface of the second side wall portion, wherein, when the second side wall portion is coupled to be located outside the first side wall portion, the convex portion is fitted into the recess portion.

Description

Technical Field

[0001] This application claims priority to Korean Patent Application No. 10-2020-0121826, filed on September 21, 2020, which is incorporated herein by reference in its entirety.

[0002] The present invention relates to a button-type secondary battery having a shape with a diameter greater than its height, and more specifically, to a button-type secondary battery in which the connecting force between the upper and lower cans is increased to prevent the upper and lower cans from separating from each other, and at the same time the gasket is more firmly fixed to improve the sealing performance between the upper and lower cans, thereby reducing the possibility of electrolyte leakage. Background Technology

[0003] Button batteries are commonly used as coin-shaped batteries, or as thin button-shaped batteries with a diameter greater than their height, and are widely used in various devices such as remote controls, clocks, toys, and computer parts.

[0004] These button-type batteries are primarily manufactured as non-rechargeable primary batteries, but with the development of miniaturized devices, they are also widely manufactured as rechargeable and dischargeable secondary batteries. Furthermore, like button-type secondary batteries or cylindrical or pouch-type secondary batteries, button-type secondary batteries also have a structure in which electrode components and electrolyte are embedded in a casing for repeated charging and discharging.

[0005] Figure 1 It is a cross-sectional view of a button-type secondary battery based on existing technology.

[0006] As shown in the figure, the button-type secondary battery has a structure in which an upper can 2 and a lower can 1 are connected to each other. Here, each of the upper can 2 and the lower can 1 has a flat cylindrical shape whose diameter is greater than its height, and the diameter of the upper can 2 is slightly larger than the diameter of the lower can 1.

[0007] An electrode assembly 4 consisting of a stacked positive electrode, a diaphragm, and a negative electrode, and an electrolyte (not shown) is placed in a lower tank 1. The electrode assembly 4 has a structure in which the diaphragm, negative electrode, and positive electrode are loaded and wound onto a rotating core. Then, a negative electrode connector extending from the negative electrode and a positive electrode connector extending from the positive electrode protrude and are respectively connected to the flat portion 1a of the lower tank 1 and the flat portion 2a of the upper tank 2.

[0008] Furthermore, a non-conductive gasket 3 is connected and positioned at the point where the flat portion 2a and side wall 2b of the upper tank 2 contact the side wall 1b of the lower tank 1, thereby preventing a short circuit when the upper tank 2 and the lower tank 1 are connected to each other. Summary of the Invention

[0009] Technical issues

[0010] However, the above-described connection method has the problem that the upper and lower cans separate when an external impact is applied. Therefore, in order to solve the above problem, the main objective of the present invention is to provide a button-type secondary battery that prevents the upper and lower cans from separating and improves the sealing performance between the lower and upper cans.

[0011] Technical solution

[0012] To achieve the above objectives, the present invention provides a button-type secondary battery in which an upper can is connected to the lower can when an electrode assembly is mounted on a lower can. The button-type secondary battery includes: a lower can comprising a first flat portion and a first sidewall, wherein the electrode assembly is disposed on the first flat portion, and the first sidewall is formed perpendicularly along the periphery of the first flat portion, wherein a recess is formed in the first sidewall to have a recessed shape; and an upper can comprising a second flat portion and a second sidewall, wherein the area of ​​the second flat portion is sufficient to cover the top surface of the opening of the lower can, and the second sidewall is formed perpendicularly along the periphery of the second flat portion, wherein a protrusion is formed on the inner surface of the second sidewall to protrude convexly, wherein when the sidewall is connected to be located outside the first sidewall, the protrusion is fitted into the recess.

[0013] The portions of the concave and convex parts that can contact each other are formed into curved surfaces.

[0014] When the protrusion is assembled to be fixed to the recess, the end of the first sidewall and the second flat portion can be spaced apart from each other.

[0015] When the gasket is attached to the end of the lower tank to surround the end of the first sidewall and the protrusion is assembled to be fixed to the recess, the gasket attached to the end of the first sidewall and the second flat portion can be spaced apart from each other.

[0016] The first sidewall may include: a sidewall body extending from the first flat portion and having a relatively small inner diameter; and an extension extending from the sidewall body and having an inner diameter relatively larger than the inner diameter of the sidewall body.

[0017] An inclined portion with an inclined cross section can be formed between the sidewall body and the extension portion to gradually increase in diameter.

[0018] When the upper can and the lower can are connected to each other, the recess and the convex portion can be configured to be closer to the first flat portion than the second flat portion.

[0019] The protrusion may have a shape that is recessed in the outer surface of the second sidewall.

[0020] The recesses can be provided in multiple ways, the recesses being spaced apart from each other in the first sidewall, and the protrusions can be provided in the second sidewall in the same number as the recesses, such that the protrusions and recesses are paired with each other.

[0021] Furthermore, the present invention can provide a secondary battery module in which multiple button-type secondary batteries, each having the above-described structure, are electrically connected to each other.

[0022] Beneficial effects

[0023] According to the present invention having the above-described structure, when the upper can and the lower can are connected to each other, the connection force between the upper can and the lower can is increased because the protrusion formed on the upper can is inserted into the recess formed on the lower can.

[0024] The parts where the concave and convex parts come into contact with each other can be formed as curved surfaces to minimize the impact and deformation that occur when the upper and lower cans are connected to each other.

[0025] When the lower tank and the upper tank are connected to each other, the first side wall of the lower tank and the second flat part of the upper tank can be spaced apart from each other to block the impact or vibration applied to the gasket, thereby preventing damage to the gasket and also preventing short circuits caused by gasket damage.

[0026] In addition, the gasket can be inserted between the first and second sidewalls and between the recess and the convex portion for a more secure fixation, thereby improving the sealing performance.

[0027] Two recesses can be formed in the first sidewall, and the same number of protrusions can be formed in the second sidewall, so as to increase the connection force between the upper and lower cans more due to the increase in the number of recesses and protrusions. Attached Figure Description

[0028] Figure 1 It is a cross-sectional view of a button-type secondary battery based on existing technology.

[0029] Figure 2 This is a cross-sectional view of a button-type secondary battery according to an embodiment of the present invention.

[0030] Figure 3 This is an example in Figure 2 A cross-sectional view of the gasket connected to the lower tank in the specified state.

[0031] Figure 4 This is an example in Figure 3 A cross-sectional view of the state in which the convex part is inserted into the concave part.

[0032] Figure 5 This is a cross-sectional view illustrating a structure with multiple recesses and protrusions. Detailed Implementation

[0033] In the following description, preferred embodiments of the invention will be detailed with reference to the accompanying drawings in a manner that allows those skilled in the art to readily implement the technical concept to which the invention pertains. However, the invention can be embodied in many different forms and should not be construed as limiting the embodiments set forth herein.

[0034] For the sake of clarity in describing the invention, parts that are not relevant to the description have been omitted, and the same reference numerals are assigned to the same or similar parts throughout the specification.

[0035] Furthermore, the terms or wording used in this specification and claims should not be construed as having a general meaning or dictionary-based meaning, but should be interpreted as meanings and concepts that are within the scope of this invention, based on the principle that the inventor can properly define the concepts of the terms to best describe and interpret his or her invention.

[0036] This invention relates to a button-type secondary battery having a diameter greater than its height. Embodiments of the invention will be described in more detail below with reference to the accompanying drawings.

[0037] First Implementation Method

[0038] Figure 2 This is a cross-sectional view of a button-type secondary battery according to an embodiment of the present invention. Figure 3 This is an example in Figure 2 A cross-sectional view of the gasket connected to the lower tank in its current state, and... Figure 4 This is an example in Figure 3 A cross-sectional view of the state in which the convex part is inserted into the concave part.

[0039] Reference Figures 2 to 4 The button-type secondary battery provided in this embodiment has a structure for injecting electrolyte, and the upper tank 20 is connected to the lower tank 10 when the electrode assembly 40 is installed on the lower tank 10.

[0040] The lower tank 10 has a first flat portion 10a and a first sidewall 10b. The electrode assembly 40 is disposed on the first flat portion 10a, and the first sidewall 10b is formed vertically along the periphery of the first flat portion 10a. The first flat portion 10a is configured as a circular plate shape according to the diameter of the button-shaped electrode assembly 40, and the first sidewall 10b has a structure that is vertically erected along the periphery of the first flat portion 10a.

[0041] Furthermore, a recess 11 is formed in the first sidewall 10b to have a concave shape on its outer surface. As shown, the recess 11 has a concave shape on the outer surface of the first sidewall 10b to protrude inward from its inner surface.

[0042] Furthermore, the upper tank 20 connected to the lower tank 10 also includes a second flat portion 20a and a second sidewall 20b. The second flat portion 20a has an area sufficient to cover the top surface of the opening of the lower tank 10, and is formed in a circular plate shape like the first flat portion 10a. The second sidewall 20b is formed to extend vertically downward along the periphery of the second flat portion 20a.

[0043] Furthermore, a protrusion 21 is formed on the second sidewall 20b to protrude convexly from its inner surface.

[0044] When the second sidewall 20b is attached to the outer side of the first sidewall 10b, the protrusion 21 is fitted into the recess 11. Additionally, the protrusion 21 is formed at a position spaced apart from the end of the first sidewall 10b on the bottom surface of the second flat portion 20a.

[0045] Furthermore, the portion of the recess 11 and the protrusion 21 that comes into contact with each other in this embodiment can also be formed as a curved surface, thereby reducing the impact when the protrusion 21 is assembled into the recess 11.

[0046] like Figure 3 As shown, in this embodiment, the lower can 10 is provided with a gasket 30 connected thereto. That is, when the lower can 10 and the upper can 20 are connected to each other, the upper can 20 is connected to the positive electrode of the electrode assembly 40, while the lower can 10 is connected to the negative electrode of the electrode assembly 40.

[0047] Therefore, the gasket 30 is connected to the lower tank 10 to surround the end of the first sidewall 10b and is disposed between the upper tank 20 and the lower tank 10, so that the upper tank 20 and the lower tank 10 are insulated from each other and the electrolyte is prevented from leaking between the upper tank 20 and the lower tank 10.

[0048] like Figure 3 As shown, the pad 30 has an upper end and a lower end, the upper end being bent to be mounted and secured to the end of the first sidewall 10b, and the lower end extending below the recess 11.

[0049] Furthermore, when the protrusion 21 is fitted into the recess 11, such as Figure 4 As shown, the gasket 30 is fitted between the recess 11 and the protrusion 21 and between the first sidewall 10b and the second sidewall 20b.

[0050] Therefore, since the recess 11 and the protrusion 21 are additionally fixed to each other, the gasket 30 can be more securely fixed between the lower tank 10 and the upper tank 20. Furthermore, the gasket 30 can be spaced apart from the bottom surface of the second flat portion 20a to block direct impacts that may be transmitted from the second flat portion 20a. Thus, impacts or vibrations transmitted to the gasket 30 can be blocked to prevent damage to the gasket, thereby preventing short circuits due to damage to the gasket 30.

[0051] In this embodiment, the first sidewall 10b has the following structure: it includes a sidewall body B and an extension D. The sidewall body B extends from the first flat portion 10a and has a relatively small inner diameter, while the extension D extends from the sidewall body B and has an inner diameter that is relatively larger than that of the sidewall body B. Furthermore, an inclined portion C is formed between the sidewall body B and the extension D, and the cross-section of the inclined portion C is inclined, thus its diameter gradually increases.

[0052] As described above, the first sidewall 10b can have different diameters in the sidewall body B, the inclined portion C, and the extension portion D. Correspondingly, when the second sidewall 20b is joined, the second sidewall 20b can be formed with different diameters, thereby increasing the connection force at the point where the lower can 10 and the upper can 20 engage with each other. For reference, the second sidewall 20b of the upper can 20 can be manufactured to be in close contact with the sidewall body B, the inclined portion C, and the extension portion D to correspond to the shape of the first sidewall 10b, and then joined by press fitting of the upper can 20 and the lower can 10. Then, as shown, after being set into a vertical plate shape, when the upper can 20 covers the lower can 10, the second sidewall 20b can be pressed and molded on the side to be in close contact with the sidewall body B, the inclined portion C, and the extension portion D.

[0053] Furthermore, in this embodiment, when connecting the upper can 20 and the lower can 10 to each other, it is preferable to set the recess 11 and the protrusion 21 to be closer to the first flat portion 10a than the second flat portion.

[0054] The protrusion 21 may have a shape that is recessed from the outer surface of the second sidewall 20b, so that the weight of the protrusion 21 is reduced and it can be slightly elastically deformed when the upper can 20 is connected.

[0055] Second Implementation Method

[0056] Figure 5 This is a cross-sectional view illustrating a structure having multiple recesses 11 and protrusions 21.

[0057] refer to Figure 5 In this embodiment, the lower tank 10 and the upper tank 20 are respectively provided with a plurality of recesses 11 and protrusions 21.

[0058] In other words, two or more recesses 11 spaced apart may also be formed in the first sidewall 10b of the lower can 10. Here, the recesses 11 need not have the same size and shape. For example, when the upper can 20 and the lower can 10 are connected to each other, the recesses 11 located on the upper side may be configured to have a shallower depth to facilitate passage through the second sidewall 20b, and the recesses 11 located on the lower side may be configured to have a greater depth to provide a stronger connection force.

[0059] Furthermore, the same number of protrusions 21 as the recesses 11 are formed in the second sidewall 20b of the upper can 20, so as to mate with the recesses 11 respectively. The protrusions 21 have dimensions and shapes that can be assembled and fixed with the corresponding recesses 11.

[0060] Furthermore, in this embodiment, the gasket 30 can be fixed by fitting it between the respective recesses 11 and the respective protrusions 21 that form a pair. In addition, when the upper can 20 and the lower can 10 are connected to each other, their upper ends are configured to be spaced apart from the bottom surface of the second flat portion 20a.

[0061] Furthermore, even in this embodiment, when the lower tank 10 and the upper tank 20 are connected to each other, the gasket 30 can be spaced apart from the bottom surface of the second flat portion 20a to block direct impacts that may be transmitted from the second flat portion 20a. Therefore, impacts or vibrations transmitted to the gasket 30 can be blocked to prevent damage to the gasket, thereby preventing short circuits due to damage to the gasket 30.

[0062] In the present invention having the above-described structure, when the upper can 20 and the lower can 10 are connected to each other, the connection force between the upper can 20 and the lower can 10 can be increased because the protrusion 21 formed on the upper can 20 is fitted into the recess 11 formed in the lower can 10.

[0063] The portions of the recess 11 and the protrusion 21 that come into contact with each other can be formed as curved surfaces to minimize the impact and deformation that occur when the upper can 20 and the lower can 10 are connected to each other.

[0064] When the lower tank 10 and the upper tank 20 are connected to each other, the first side wall 10b of the lower tank 10 and the second flat portion 20a of the upper tank 20 can be spaced apart from each other to block the impact or vibration applied to the gasket 30, thereby preventing damage to the gasket 30 and also preventing short circuits due to gasket damage.

[0065] Furthermore, the gasket 30 is fitted between the recess 11 and the protrusion 21 and between the first sidewall 10b and the second sidewall 20b, thereby securing it more firmly and improving the sealing performance.

[0066] Since two or more recesses 11 are formed in the first sidewall 10b, and protrusions 21 are formed in the second sidewall 20b in the same number as the recesses 11, the connecting force between the upper can 20 and the lower can 10 can be increased as the number of recesses 11 and protrusions 21 increases.

[0067] In addition, the present invention may provide a secondary battery module in which multiple button-type secondary batteries having the above-mentioned characteristics are electrically connected to each other.

[0068] Although embodiments of the invention have been described with reference to specific examples, it will be apparent to those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention as defined by the claims.

[0069] [Description of reference numerals in the attached figures]

[0070] 10: Lowering the can

[0071] 10a: First flat portion; 10b: First sidewall

[0072] 11: concave part

[0073] 20: Upper jar

[0074] 20a: Second flat portion; 20b: Second sidewall

[0075] 21: convex part

[0076] 30: Padding

Claims

1. A button-type secondary battery, the button-type secondary battery comprising: A lower can, the lower can including a first flat portion and a first sidewall, an electrode assembly disposed on the first flat portion, the first sidewall being formed perpendicularly along the periphery of the first flat portion, wherein a recess is formed in the outer surface of the first sidewall to have a recessed shape; and An upper can is connected to a lower can, and the upper can includes a second flat portion and a second sidewall. The area of ​​the second flat portion is sufficient to cover the top surface of the opening of the lower can. The second sidewall is formed perpendicularly along the periphery of the second flat portion, wherein a protrusion is formed on the inner surface of the second sidewall to project convexly. When the second sidewall is connected to be located outside the first sidewall, the protrusion is fitted into the recess. The first sidewall includes: Sidewall body, the sidewall body extending from the first flat portion; and An extension portion extends from the sidewall body, and the inner diameter of the extension portion is larger than the inner diameter of the sidewall body. In this configuration, an inclined portion with an inclined cross-section is formed between the sidewall body and the extended portion to gradually increase in diameter. Wherein, when the gasket is attached to the end of the lower tank to surround the first sidewall and the protrusion is assembled to be fixed to the recess, the gasket attached to the end of the first sidewall and the second flat portion are spaced apart from each other, and Wherein, when the upper can and the lower can are connected to each other, the recess and the convex portion are configured to be closer to the first flat portion than the second flat portion.

2. The button-type secondary battery according to claim 1, wherein, The portions where the concave and convex parts contact each other are formed as curved surfaces.

3. The button-type secondary battery according to claim 1, wherein, The protrusion has a shape that is recessed in the outer surface of the second sidewall.

4. The button-type secondary battery according to claim 1, wherein, The recess is configured as a plurality of recesses, which are spaced apart from each other in the first sidewall, and The protrusions are provided in the second sidewall in the same number as the recesses, such that the protrusions and the recesses are paired with each other.

5. A secondary battery module, wherein a plurality of button-type secondary batteries according to any one of claims 1 to 4 are electrically connected to each other.

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