Secondary battery

Abstract

Embodiments of the present application relate to a cylindrical secondary battery having an improved current collecting structure. According to the present application, an elastic portion is integrally or detachably provided with a current collecting plate, so that it can absorb an impact from external vibration. Thus, a problem that a substrate of an electrode assembly is crushed or compacted can be minimized.

Description

Technical Field

[0001] Embodiments of the present invention relate to a cylindrical secondary battery having an improved current collection structure. Background Technology

[0002] Typically, a cylindrical secondary battery includes a cylindrical electrode assembly, a cylindrical can containing the electrode assembly and electrolyte, and a cover assembly attached to the top opening of the can to seal the can and allow current generated in the electrode assembly to flow to an external device.

[0003] Typically, to reduce the resistance of electrode assemblies, the current collector structure of the electrode assembly mainly uses a method of gathering multiple substrates protruding from the electrode plate and connecting the substrates with wires. However, unlike the areas coated with active material, such a current collector structure results in a large number of empty spaces in the areas where the substrates of the electrode plate protrude. Therefore, when vibration occurs, the protruding substrates may bend or compact. Consequently, due to the increased movement of the electrode assembly, the stress transmitted to the solder joints between the substrates and the current collector increases, making the current collector itself more susceptible to vibration.

[0004] As a technology to address the above problems, there is a method for collecting multiple substrates, connecting lead terminals to the substrates, and directly soldering the terminals of the can to the current collector. However, this structure restricts design freedom due to the narrow gap between the electrode assembly and the current collector, and the addition of lead terminals leads to additional material costs and processes, increased component resistance, etc.

[0005] The information disclosed in this background section is only intended to enhance the understanding of the background of the present invention, and therefore may contain information that does not constitute prior art. Summary of the Invention

[0006] Technical issues

[0007] This invention provides a cylindrical secondary battery with improved vibration resistance and an enhanced current collection structure.

[0008] Technical solution

[0009] A secondary battery according to an embodiment of the present invention includes: a can having a cylindrical shape open at one end; an electrode assembly housed in the can, wherein a first electrode plate, a separator, and a second electrode plate are stacked and wound into a cylindrical shape in the electrode assembly, wherein a first electrode uncoated portion of the first electrode plate protrudes at one end of the electrode assembly in the longitudinal direction, and a second electrode uncoated portion of the second electrode plate protrudes at the other end of the electrode assembly in the longitudinal direction; a cover assembly configured to close the open end of the can when the electrode assembly is housed in the can; and a first electrode current collector inserted into one end of the electrode assembly in the longitudinal direction. The electrode assembly includes a can connecting portion, an elastic portion, and multiple substrate current collectors. The multiple substrate current collectors protrude from the plate surface and are electrically connected to the uncoated portion of the first electrode. The can connecting portion is spaced apart from the substrate current collectors and electrically connected to the can. The elastic portion elastically deforms in the longitudinal direction of the electrode assembly. The electrode assembly also includes a second electrode current collector plate, which is inserted into the other end of the electrode assembly in the longitudinal direction. The second electrode current collector plate also includes a can connecting portion, an elastic portion, and multiple substrate current collectors. The multiple substrate current collectors protrude from the plate surface and are electrically connected to the uncoated portion of the second electrode. The can connecting portion is spaced apart from the substrate current collectors and electrically connected to the cover assembly. The elastic portion elastically deforms in the longitudinal direction of the electrode assembly.

[0010] The first electrode current collector and the second electrode current collector have the same shape and are arranged symmetrically to each other.

[0011] The elastic part is integrally formed with the corresponding plate surfaces of the first electrode current collector and the second electrode current collector.

[0012] The elastic portion is formed separately and is bonded to the corresponding plate surfaces of the first electrode current collector and the second electrode current collector.

[0013] The first electrode current collector and the second electrode current collector have a disk shape, and multiple substrate current collectors are formed and protrude in the radial direction.

[0014] The elastic part has a concave-convex shape formed by a portion of the surface of the cutting plate and is spaced apart from the current collection part of the substrate.

[0015] The elastic part is formed by cutting a portion of one of the multiple substrate current collectors arranged in a straight line and bending the portion multiple times, and the cut end of the elastic part is used as a can connection part.

[0016] The elastic part has a concave-convex shape formed by cutting a portion of the substrate current collection part arranged in a straight line among a plurality of substrate current collection parts, and the cut end of the elastic part serves as a can connection part.

[0017] Each of the multiple substrate current collectors has a width greater than the width of the elastic portion.

[0018] The elastic part includes a disc-shaped leaf spring with a diameter equal to or smaller than the diameter of the first electrode current collector and the second electrode current collector.

[0019] One end of the elastic part is physically and electrically connected to the first electrode current collector or the second electrode current collector, and the other end of the elastic part is physically and electrically connected to the can or lid assembly.

[0020] The elastic part includes a conductive material.

[0021] The protruding direction of the current collecting portion of the substrate of the first electrode current collector is oriented toward the uncoated portion of the first electrode, and the protruding direction of the current collecting portion of the substrate of the second electrode current collector is oriented toward the uncoated portion of the second electrode.

[0022] Each of the plurality of substrate current collection portions of the first electrode current collector includes a welding surface that is welded to an uncoated portion of the first electrode, and each of the plurality of substrate current collection portions of the second electrode current collector includes a welding surface that is welded to an uncoated portion of the second electrode.

[0023] Beneficial effects

[0024] According to the present invention, the elastic portion is provided integrally with or detachably from the current collector, thus absorbing the impact from external vibrations. Therefore, the problem of the electrode assembly substrate being flattened or compacted can be minimized. Attached Figure Description

[0025] Figure 1 This is a vertical sectional view showing a cylindrical secondary battery according to an embodiment of the present invention.

[0026] Figure 2 This is a perspective view showing a manifold according to a first embodiment of the present invention.

[0027] Figure 3 yes Figure 2 A partial perspective view of the manifold.

[0028] Figure 4 It is shown Figure 2 A perspective view of the manifold and manifold structure.

[0029] Figure 5 This is a perspective view showing a manifold according to a second embodiment of the present invention.

[0030] Figure 6 yes Figure 5 A partial perspective view of the manifold.

[0031] Figure 7 This is a perspective view showing a manifold according to a third embodiment of the present invention.

[0032] Figure 8 It is shown Figure 7A perspective view of the manifold and manifold structure.

[0033] Figure 9 This is an exploded perspective view showing a manifold according to a fourth embodiment of the present invention.

[0034] Figure 10 It is shown Figure 9 A side sectional view of the manifold. Detailed Implementation

[0035] Embodiments of the invention are provided to more fully describe the invention to those skilled in the art. The following embodiments can be modified in many different ways, and the scope of the invention is not limited to the following embodiments. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of the invention to those skilled in the art.

[0036] Furthermore, in the accompanying drawings, for ease of explanation and clarity, the thickness and dimensions of each layer are exaggerated, and the same reference numerals always refer to the same elements. As used in this specification, the term "and / or" includes any and all combinations of one or more of the associated listed items. Additionally, it will be understood in this specification that when component A is referred to as being "connected to" component B, component A may be directly connected to component B, or component C may be placed between component A and component B such that component A is indirectly connected to component B.

[0037] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the invention. As used herein, the singular form may include the plural form unless the context clearly indicates otherwise. Furthermore, it will be understood that when the terms “comprising or including” and / or variations thereof are used herein, it indicates the presence of the stated features, quantities, steps, operations, components, elements, and / or groups thereof, but does not preclude the presence or addition of one or more other features, quantities, steps, operations, components, elements, and / or groups thereof.

[0038] In this specification, while the terms first, second, etc., may be used to describe various components, assemblies, regions, layers, and / or portions, it is apparent that these components, assemblies, regions, layers, and / or portions should not be limited by these terms. These terms are used only to distinguish one component, assembly, region, layer, or portion from another. Therefore, without departing from the teachings of this invention, the first component, first assembly, first region, first layer, or first portion described below may also refer to a second component, second assembly, second region, second layer, or second portion.

[0039] To facilitate understanding of one element or feature and another (other) element or feature as shown in the accompanying drawings, spatial relative terms such as "below," "under," "lower," "above," and "upper" are used herein. These spatial relative terms are intended to facilitate understanding of the invention in various states of manufacture or use according to the invention, and therefore, the invention is not limited thereto. For example, when the elements or features in the drawings are flipped, elements and features described as "below" or "under" are changed to "above" or "upper." Thus, the term "below" can encompass both "above" and "lower."

[0040] In the following, a secondary battery according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

[0041] Figure 1 This is a vertical sectional view showing a cylindrical secondary battery according to an embodiment of the present invention.

[0042] like Figure 1 As shown, the cylindrical secondary battery 10 according to an embodiment of the present invention may include a cylindrical can 110, an electrode assembly 130 inserted into the can 110, a cover assembly 150 coupled to one end of the can 110, and a first electrode current collector 170 and a second electrode current collector 190 connecting the electrode assembly 130 to the can 110 and the cover assembly 150.

[0043] The can 110 includes a circular bottom 112 and a side 114 extending upward from the bottom 112, and has a cylindrical shape with the upper end of the side 114 open (hereinafter referred to as the opening). In the manufacturing process of the secondary battery 10, the electrode assembly 130 is inserted into the can 110 along with the electrolyte via the opening of the can 110. The electrode assembly 130 is electrically connected to the can 110 and the cover assembly 150 via a first electrode plate 132 and a second electrode plate 134. The can 110 may be made of steel, steel alloy, nickel-plated steel, nickel-plated steel alloy, aluminum, aluminum alloy, or equivalents thereof, but the material of the can is not limited thereto. With the electrode assembly 130 housed inside the can 110, the cover assembly 150 is inserted into the opening to close it.

[0044] Electrode assembly 130 includes a first electrode plate 132, a second electrode plate 134, and a separator 136. The first electrode plate 132 is a negative electrode plate coated with a negative electrode active material (e.g., graphite, carbon, etc.), and the second electrode plate 134 is a positive electrode plate coated with a positive electrode active material (e.g., transition metal oxides (LiCoO2, LiNiO2, LiMn2O4, etc.)). The separator 136 is disposed between the first electrode plate 132 and the second electrode plate 134 to prevent short circuits and to allow only lithium ion movement. The first electrode plate 132, the second electrode plate 134, and the separator 136 may be wound into a generally cylindrical shape and housed inside a can 110. The first electrode plate 132 may include copper (Cu) foil or nickel (Ni) foil, the second electrode plate 134 may include aluminum (Al) foil, and the separator 136 may include polyethylene (PE) or polypropylene (PP). However, in this invention, their materials are not limited to these materials.

[0045] Uncoated portions, untouched by any active material, can be formed in the first electrode plate 132 and the second electrode plate 134. For example, the first electrode plate 132, used as a negative electrode plate, may have a first electrode uncoated portion 132a at its lower end, untouched by any negative electrode active material, and the second electrode plate 134, used as a positive electrode plate, may have a second electrode uncoated portion 134a at its upper end, untouched by any positive electrode active material. The first electrode current collector 170 and the second electrode current collector 190, which will be described later, are respectively connected to the first electrode uncoated portion 132a and the second electrode uncoated portion 134a, thus the can 110 and the cap assembly 150 are electrically connected to the electrode assembly 130.

[0046] The cap assembly 150 is attached to the upper opening of the can 110 and is used to seal the can 110. The cap assembly 150 may include an upper cap 151 located in the outermost region, a safety vent 152 attached to the lower part of the upper cap 151, a lower cap 153 attached to the lower part of the safety vent 152, an insulator 154 inserted between the safety vent 152 and the lower cap 153, and an insulating gasket 156 inserted between the cap assembly 150 and the can 110. The upper cap 151 has upwardly projecting terminals and is electrically connected to the outside of the secondary battery 10. When gas is generated inside the secondary battery 10 due to overcharging or abnormality, the safety vent 152 ruptures when the gas pressure exceeds a certain pressure and releases the gas to prevent damage to the secondary battery 10. The lower cap 153 supports the safety vent 152 from below, and a through hole is formed in the center of the lower cap 153, such that a portion of the safety vent 152 protrudes through the through hole and is electrically connected to the lower cap 153. Insulator 154 insulates the safety vent 152 from the lower cover 153. This is merely an exemplary configuration, and the configuration of the cover assembly 150 is not limited to the above configuration.

[0047] The current collection structure for electrically connecting electrode assembly 130 to tank 110 will be described in detail below. Various embodiments have structures that can be applied to both the first electrode current collector and the second electrode current collector. For convenience, the detailed structure will be described based on the first electrode current collector.

[0048] Figure 2 This is a perspective view showing a manifold according to a first embodiment of the present invention. Figure 3 yes Figure 2 A partial perspective view of the manifold. Figure 4 It is shown Figure 2 A perspective view of the manifold and manifold structure.

[0049] like Figures 2 to 4 As shown, the manifold according to the first embodiment of the present invention includes a first electrode manifold 170 to which a first electrode plate 132, serving as a negative electrode plate, is electrically connected to the bottom surface of the tank 110. Therefore, the first electrode manifold 170 can be referred to as a negative electrode manifold. The second electrode manifold 190 includes a substrate manifold portion 192 with a welding surface, a tank connection portion 194, and an elastic portion 196, and may have the same structure as the first electrode manifold 170. Figure 4 As shown, the second electrode current collector 190 is symmetrically mounted facing the first electrode current collector 170.

[0050] The first electrode current collector 170 has an approximately disk-like shape and is welded to the uncoated portion 132a of the first electrode 132 and the bottom surface of the can 110. Therefore, the first electrode 132 is electrically connected to the bottom surface of the can 110. For this purpose, a substrate current collector 172 welded to the uncoated portion 132a and a can connection portion 174 welded to the can 110 can be formed on the first electrode current collector 170. Furthermore, an elastic portion 176 can be provided between the substrate current collector 172 and the can connection portion 174 to reduce the impact applied to the substrate current collector 172.

[0051] The substrate current collector 172 has a certain length in the radial direction of the electrode assembly 130 (the radial direction of the first electrode current collector plate). The substrate current collector 172 is formed radially in the remaining area except for a local area of ​​the central portion of the first electrode current collector plate 170 and protrudes from it. The protruding direction of the substrate current collector 172 is oriented toward the bottom surface of the can 110 on the side opposite to the cover assembly 150. For example, four substrate current collectors 172 can be formed and protrude simultaneously at 90-degree intervals in the radial direction of the electrode assembly 130. For example, the width of the substrate current collector 172 can be the same as or similar to the width of the elastic portion 176. Furthermore, for example, the radial length of the substrate current collector 172 can be obtained by subtracting the radius of the can connection portion 174 from the radius of the first electrode current collector plate 170. For example, the substrate current collector 172 can protrude in the form of a quadrilateral or circular cross-section. The uncoated portion 132a of the first electrode is welded to the upper surface of the protruding surface of the current collector 172 on the substrate, and this upper surface is defined as the welding surface 172a.

[0052] The can connection portion 174 includes a region welded to the bottom surface of the can 110 and may include a specific region of the central portion of the first electrode current collector 170. The can connection portion 174 includes a region where the substrate current collector 172 or the elastic portion 176 is not formed. The can connection portion 174 is welded to the bottom of the can 110, and the substrate current collector 172 is welded to the first electrode uncoated portion 132a of the first electrode plate 132. Therefore, the first electrode plate 132 and the bottom of the can 110 can be electrically connected to each other. For this purpose, the region of the can connection portion 174 has a height lower than the height of the protruding portion of the substrate current collector 172 or the elastic portion 176, which will be described later. Preferably, the region of the can connection portion 174 may have the same height as the plate surface of the first electrode current collector 170 where the substrate current collector 172 or the elastic portion 176 is not formed. When the structure of the first electrode current collector 170 is similarly applied to the second electrode current collector, the can connection portion 194 can be welded and electrically connected to the cover assembly 150. The elastic portion 176 is formed in the area other than the area where the substrate current collection portion 172 and the can connection portion 174 are formed.

[0053] The elastic portion 176 has a certain length in the radial direction of the electrode assembly 130 (the radial direction of the first electrode current collector plate) and is integrally formed with the first electrode current collector plate 170. Furthermore, the elastic portion 176 is formed radially in the remaining area except for a localized region of the central portion of the first electrode current collector plate 170, and is provided in areas where the substrate current collector 172 is not formed. In other words, the elastic portion 176 is provided on the current flow path between the substrate current collector 172 and the can connection portion 174, thus increasing the length of the path. The elastic portion 176 is formed by cutting a portion of the plate surface, connecting both ends in the longitudinal direction (length direction) to the plate surface, and processing it into a specific shape in the longitudinal direction. The elastic portion 176 may have an uneven shape, in which a portion protruding from the bottom surface on the side opposite to the cap assembly 150 facing the can 110 and a portion recessed in the opposite direction are alternately repeated. The alternating protrusions and recesses give the elastic portion 176 elasticity and flexibility. Therefore, the elastic portion 176 can absorb the impact caused by external vibration. For example, four elastic portions 176 can be formed at 90-degree intervals in the radial direction of the electrode assembly 130. For example, the width of the elastic portion 176 can be the same as or similar to the width of the substrate current collector 172. Furthermore, for example, the length of the elastic portion 176 in the radial direction can be less than the length of the substrate current collector 172. For example, the elastic portion 176 can protrude in the form of a quadrilateral or circular cross-section. The size and shape of the elastic portion 176 can vary depending on the size and shape of the substrate current collector 172.

[0054] The uncoated portion 132a of the first electrode of the first electrode plate 132 and the uncoated portion 134a of the second electrode of the second electrode plate 134 protrude in the lower and upper directions of the electrode assembly 130. Therefore, when individual lead tabs are provided, the capacity of the secondary battery 10 is reduced due to the space required to bend the lead tabs. Without lead tabs, when the uncoated portions are aggregated and connected by individual wires, a large amount of empty space is created, and the uncoated portions (substrate) are flattened or compacted when external vibrations are generated and transmitted. Therefore, the amount of movement of the electrode assembly increases, and the stress transmitted to the solder joint between the uncoated portions and the current collector increases.

[0055] However, in this invention, no separate lead terminals are provided, thus minimizing the reduction in the capacity of the secondary battery 10. Furthermore, in this invention, the uncoated portion is directly soldered to the substrate current collector 172, and an elastic portion 176, serving as a vibration-resistant buffer, is provided between the area soldered to the substrate (substrate current collector) and the area soldered to the can 110, which serves as a terminal (can connection). Therefore, when external vibrations are generated and transmitted, the stress applied to the substrate soldering area can be dispersed. This prevents the substrate from being pressed, compacted, or torn, and prevents the solder joints from detaching. Additionally, due to the provision of the elastic portion 176, even if the distance between solder points increases due to the movement of the electrode assembly 130, the tension applied to the substrate current collector 172 can be reduced due to the extensibility and elasticity of the elastic portion 176.

[0056] The elastic part with the above structure can be changed to various forms (detailed descriptions of the same structure, function and effect as in the foregoing embodiments will be omitted).

[0057] Figure 5 This is a perspective view showing a manifold according to a second embodiment of the present invention. Figure 6 yes Figure 5 A partial perspective view of the manifold.

[0058] like Figure 5 and Figure 6 As shown, according to the second embodiment of the present invention, four substrate current collectors 272 having a certain width can be formed at 90-degree intervals and protrude from the disk of the first electrode current collector 270. Here, each of the substrate current collectors 272 is formed along the radial direction of the first electrode current collector 270 and can have a width larger than the width of the substrate current collector 172 formed in the first electrode current collector 170 according to the first embodiment. For example, when the width of the substrate current collector 172 according to the first embodiment is x, the substrate current collector 272 according to the second embodiment can have a width of 3x. Furthermore, the length of the substrate current collector 272 can be equal to, greater than or less than the length of the substrate current collector 172 according to the first embodiment. The cross-section of the substrate current collector 272 can have the same shape as the cross-section of the substrate current collector 172 according to the first embodiment. For example, when four substrate current collectors 272 are formed, the can connection portion 274 and the elastic portion 276 can be integrally formed on two substrate current collectors 272 forming a straight line.

[0059] The can connection portion 274 and the elastic portion 276 can be formed by cutting the upper surface of the substrate current collector 272, which forms a straight line in the longitudinal direction, and bending one side of it. When the cut sheet is like Figure 5When folded multiple times as shown, the bent portion serves as an elastic portion 276, and the end located on the same plate surface as or parallel to the plate surface of the first electrode current collector 270 serves as a can connection portion 274. The can connection portion 274 is a portion cut from a substrate current collector 272, and therefore connects to the substrate current collector 272 connected to the elastic portion 276. However, the can connection portion 274 has a free end that is not connected to the substrate current collector 272 facing the same substrate current collector 272 connected to the elastic portion 276. The free end of the can connection portion 274 is welded and fixed to the bottom surface of the can 110. For example, the elastic portion 276 can be bent once at an acute angle from the upper surface of a substrate current collector 272, and then bent again. Here, the later-bent portion can form an acute angle with the can connection portion 274.

[0060] Figure 7 This is a perspective view showing a manifold according to a third embodiment of the present invention. Figure 8 It is shown Figure 7 A perspective view of the manifold and manifold structure.

[0061] like Figure 7 and Figure 8 As shown, according to the third embodiment of the present invention, four substrate current collectors 372 having a certain width can be formed at 90-degree intervals and protrude from the disk of the first electrode current collector 370. Here, each of the substrate current collectors 372 is formed along the radial direction of the first electrode current collector 370 and can have a width greater than the width of the substrate current collector 172 formed in the first electrode current collector 170 according to the first embodiment. For example, when the width of the substrate current collector 172 according to the first embodiment is x, the substrate current collector 372 according to the third embodiment can have a width of 3x. Furthermore, a pair of substrate current collectors 372 arranged in a straight line can have a width of 3x, and another pair of substrate current collectors 372 can have different widths. In addition, the length of the substrate current collector 372 can be equal to, greater than or less than the length of the substrate current collector 172 according to the first embodiment. The cross-section of the substrate current collector 372 can have the same shape as the cross-section of the substrate current collector 172 according to the first embodiment. For example, when four substrate current collection sections 372 are formed, the can connection section 374 and the elastic section 376 can be integrally formed on two substrate current collection sections 372 forming a straight line.

[0062] The can connection portion 374 and the elastic portion 376 can be formed by cutting the upper surface of the substrate current collector 372, which is formed into a straight line in the longitudinal direction, and bending one side into a concave-convex shape. When the cut sheet is processed into such a shape... Figure 7In the case of the uneven shape shown, the uneven portion serves as the elastic part 376, and the end located on the same plate surface as the plate surface of the first electrode current collector 370 or parallel to the plate surface of the first electrode current collector 370 serves as the can connection part 374. The can connection part 374 is a portion cut from a substrate current collector 372, and therefore connected to the substrate current collector 372 connected to the elastic part 376. However, the can connection part 374 has a free end that is not connected to the substrate current collector 372 facing the same substrate current collector 372 connected to the elastic part 376. The free end of the can connection part 374 is connected and fixed to the bottom surface of the can 110 by welding.

[0063] In addition, the elastic part may not be formed on the manifold, but may be formed separately and combined with the manifold.

[0064] Figure 9 This is an exploded perspective view showing a manifold according to a fourth embodiment of the present invention. Figure 10 It is shown Figure 9 A side sectional view of the manifold.

[0065] like Figure 9 As shown in Figure 10, according to the fourth embodiment of the present invention, four substrate current collectors 472 having a certain width can be formed at 90-degree intervals and protrude from the disk-shaped region of the first electrode current collector 470. For example, the substrate current collectors 472 can have the same shape and size as the first electrode current collector 170 according to the first embodiment. However, unlike the above embodiments, the elastic portion 476 may not be integrally formed on the first electrode current collector 470, but may be formed separately and attached to the first electrode current collector 470.

[0066] The elastic portion 476 may include a disc-shaped leaf spring with a diameter equal to or slightly smaller than the diameter of the first electrode current collector 470. The elastic portion 476 is formed such that its elastic deformation direction is the same as the longitudinal direction of the electrode assembly 130, and may include a conductive material. The edge of the elastic portion 476 may be attached to or welded to the plate surface of the first electrode current collector 470 in its peripheral direction. The first electrode current collector 470 is not welded to the can 110, but is physically and electrically connected to the elastic portion 476, and one end of the elastic portion 476 is physically and electrically connected to the bottom surface of the can 110. Therefore, the first electrode current collector 470 and the can 110 can be electrically connected to each other.

[0067] According to the present invention as described above, the elastic portion is integrally or detachably provided with the current collector, thus absorbing the impact from external vibrations. Therefore, the problem of the electrode assembly substrate being flattened or compacted can be minimized.

[0068] The above embodiments are merely examples for carrying out the present invention. The present invention is not limited to the embodiments. Without departing from the subject matter of the invention as set forth in the appended claims, the technical spirit of the present invention includes all the scope of techniques that can be modified in various ways by those skilled in the art to which the present invention pertains.

[0069] Industrial practicality

[0070] This invention can be used in the field of secondary batteries.

Claims

1. A secondary battery, the secondary battery comprising: The can has a cylindrical shape with one end open; An electrode assembly is housed in the can, wherein a first electrode plate, a diaphragm, and a second electrode plate are stacked and wound into a cylindrical shape in the electrode assembly, wherein a first electrode uncoated portion of the first electrode plate protrudes at one end of the electrode assembly in the longitudinal direction, and a second electrode uncoated portion of the second electrode plate protrudes at the other end of the electrode assembly in the longitudinal direction. A cap assembly is configured to close the open end of the can while the electrode assembly is housed within the can; A first electrode current collector plate is inserted into one end of the electrode assembly in the longitudinal direction and includes: a plurality of substrate current collectors protruding from the plate surface and electrically connected to the uncoated portion of the first electrode; a can connection portion spaced apart from the substrate current collectors and electrically connected to the can; an elastic portion that elastically deforms in the longitudinal direction of the electrode assembly; and The second electrode current collector is inserted into the other end of the electrode assembly in the longitudinal direction and includes: a plurality of substrate current collectors protruding from the plate surface and electrically connected to the uncoated portion of the second electrode; a can connection portion spaced apart from the substrate current collectors and electrically connected to the cover assembly; and an elastic portion that elastically deforms in the longitudinal direction of the electrode assembly. The tank connection portion has a height corresponding to the corresponding plate surfaces of the first electrode current collector and the second electrode current collector, and is formed at the center of the corresponding plate surfaces of the first electrode current collector and the second electrode current collector. The first electrode current collector and the second electrode current collector have a disk shape, and the current collection portion of the substrate is formed and protrudes in the radial direction.

2. The secondary battery according to claim 1, wherein, The first electrode current collector and the second electrode current collector have the same shape and are arranged symmetrically to each other.

3. The secondary battery according to claim 1, wherein, The elastic portion is integrally formed with the corresponding plate surfaces of the first electrode current collector and the second electrode current collector.

4. The secondary battery according to claim 1, wherein, The elastic portion is formed separately and is attached to the respective plate surfaces of the first electrode current collector and the second electrode current collector.

5. The secondary battery according to claim 3, wherein, The elastic portion has an uneven shape formed by cutting a portion of the plate surface and is spaced apart from the substrate current collection portion.

6. The secondary battery according to claim 3, wherein, The elastic portion is formed by cutting a portion of one of the multiple substrate current collectors arranged in a straight line and bending the portion multiple times, and the cut end of the elastic portion serves as the can connection portion.

7. The secondary battery according to claim 3, wherein, The elastic portion has an uneven shape formed by cutting a portion of one of the multiple substrate current collectors arranged in a straight line, and the cut end of the elastic portion serves as the can connection portion.

8. The secondary battery according to claim 6 or 7, wherein, Each substrate current collector has a width greater than the width of the elastic portion.

9. The secondary battery according to claim 4, wherein, The elastic part includes a disc-shaped leaf spring with a diameter equal to or smaller than the diameters of the first electrode current collector and the second electrode current collector.

10. The secondary battery according to claim 9, wherein, One end of the elastic portion is physically and electrically connected to the first electrode current collector or the second electrode current collector, and the other end of the elastic portion is physically and electrically connected to the can or the lid assembly.

11. The secondary battery according to claim 10, wherein, The elastic part includes a conductive material.

12. The secondary battery according to claim 1, wherein, The protruding direction of the plurality of substrate current collection portions of the first electrode current collector is oriented toward the uncoated portion of the first electrode, and the protruding direction of the plurality of substrate current collection portions of the second electrode current collector is oriented toward the uncoated portion of the second electrode.

13. The secondary battery according to claim 12, wherein, Each of the plurality of substrate current collection portions of the first electrode current collector includes a welding surface that is welded to the uncoated portion of the first electrode, and each of the plurality of substrate current collection portions of the second electrode current collector includes a welding surface that is welded to the uncoated portion of the second electrode.

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