Cylindrical secondary battery, battery pack, and mobile unit

Abstract

The present specification provides a cylindrical secondary battery, a battery pack, and a mobile unit, the cylindrical secondary battery including: an electrode assembly including a first electrode, a second electrode, and a separator interposed therebetween, the electrode assembly having a structure in which the first electrode, the second electrode, and the separator are sequentially stacked and coiled, the first electrode including an uncoated portion, which is free of an active material, on one side of a current collector, the uncoated portion including a first electrode tab bent toward a center of the coiling or an outer contour from an end portion of the electrode assembly; a battery can receiving the electrode assembly through an open portion formed on one side; a current collector plate including three or more tab junctions electrically connected to the first electrode tab and a can junction having a continuous outer circumferential surface extending from an end portion of the tab junctions toward the open portion of the battery can and electrically connected to an inner surface of the battery can; and a top cover covering the open portion of the battery can.

Description

[0001] This application is a divisional application of the invention patent application with application number 202210203117.4 (application date March 2, 2022, invention title "Cylindrical Secondary Battery, Battery Pack and Mobile Unit"). Technical Field

[0002] This application claims the benefit of Korean Patent Application No. 10-2021-0030315, filed with the Korean Patent Office on March 8, 2021, all of which is disclosed in the documents of that Korean Patent Application and is included in this specification.

[0003] This invention relates to a cylindrical secondary battery, a battery pack including the same, and a mobile unit. Background Technology

[0004] Conventional cylindrical secondary batteries typically have a structure in which tabs connecting the gel roll and external terminals are soldered to the foil of the gel roll for connection. In the case of cylindrical secondary batteries with such a structure, the current path is limited, and the resistance of the gel roll itself must be very high.

[0005] Therefore, attempts were made to reduce resistance by increasing the number of tabs connecting the gel roll and the external terminals. However, simply increasing the number of tabs in this way can reduce the resistance to the desired level and adequately ensure that the current path is limited.

[0006] Currently, there is a need to develop gel roll structures and current collector structures to reduce the resistance of the gel roll itself. This is especially true in devices like electric vehicles that require high-power / high-capacity battery packs.

[0007] In addition, there is a need to develop a cylindrical secondary battery with a structure that maintains and enhances the bonding force between the current collector and the battery canister, as well as a current collector structure suitable for such a cylindrical secondary battery. Summary of the Invention

[0008] The problem that the invention aims to solve

[0009] The present invention was developed in view of the above-mentioned problems, and the purpose of the present invention is to provide a cylindrical secondary battery, a battery pack including the same, and a mobile unit.

[0010] In addition, the present invention aims to provide a cylindrical secondary battery, which includes a current collector plate having a structure that improves the bonding force at the joint with the battery canister and increases the energy density.

[0011] However, the problems to be solved by the present invention are not limited to those described above. Those skilled in the art can clearly understand other problems not mentioned in this specification from the following description of the invention.

[0012] Methods for solving problems

[0013] To achieve the above objectives, the present invention provides a cylindrical secondary battery with the following side, a battery pack including the secondary battery, and a moving unit.

[0014] According to one aspect of the present invention, a cylindrical secondary battery is provided, comprising: an electrode assembly having a structure in which a first electrode, a second electrode and a separator therebetween are sequentially stacked and wound up, wherein the first electrode includes an uncoated portion of uncoated active material on the current collector side, and the uncoated portion includes a first electrode tab bent from the end of the electrode assembly toward the winding center or the outer contour direction. A battery can housing the aforementioned electrode assembly through an opening formed on one side; A current collector includes: three or more tab joints electrically connected to the first electrode tab; and a can joint extending from the end of the tab joint toward the open portion of the battery can and electrically connected to the inner surface of the battery can, and having a continuous outer peripheral surface; and The top cover covers the open portion of the aforementioned battery canister.

[0015] According to one aspect of the present invention, a battery pack comprising a cylindrical secondary battery according to the above-described aspect is provided.

[0016] According to one aspect of the present invention, a movable unit comprising a battery pack according to the above-described aspect is provided.

[0017] Invention Effects

[0018] According to one aspect of the invention, the welding process between the cathode current collector and the battery canister is omitted, thereby simplifying the manufacturing process of the cylindrical secondary battery and improving productivity.

[0019] In addition, the current collector does not extend to the crimping part, thus preventing the possibility of leakage due to the partial gap created by the insertion of the current collector.

[0020] However, the effects obtained by the present invention are not limited to those described above, and those skilled in the art can clearly understand other technical effects not mentioned in this specification from the following description of the invention. Attached Figure Description

[0021] Figure 1 This shows a previous type of collector board.

[0022] Figure 2 It is applicable Figure 1 The diagram shows a cross-sectional view of a conventional current collector-type cylindrical secondary battery.

[0023] Figure 3 A current collector board according to an embodiment of the present invention is shown.

[0024] Figure 4 Show applicable Figure 3 The diagram shows a side cross-section of a cylindrical secondary battery with a current collector plate.

[0025] Figure 5 A battery pack including a cylindrical secondary battery according to one embodiment is shown.

[0026] Figure 6 A mobile unit including a battery pack according to one embodiment is shown.

[0027] (Symbol Explanation)

[0028] 1: Cylindrical secondary battery

[0029] 2: Assembly of the outer shell

[0030] 3: Battery pack

[0031] 5: Moving Unit

[0032] 10: Electrode assembly

[0033] 11: First electrode tab

[0034] 20: Battery can

[0035] 21: Rolled edge

[0036] 22: Crimping section

[0037] 30: Current collector

[0038] 31: Central Section

[0039] 32: Electrode junction

[0040] 33: Tank joint

[0041] 40: Top Cover

[0042] G1: Sealing gasket Detailed Implementation

[0043] This invention is subject to various modifications and may include various embodiments, but specific embodiments are illustrated in the accompanying drawings, and detailed description is based on these drawings. However, this is not intended to limit the invention to a specific embodiment; the invention includes all modifications, equivalents, or substitutions that fall within the technical concept and scope of the invention.

[0044] In this specification, terms such as first, second, A, and B are used to describe various constituent elements, but the constituent elements are not limited to these terms. These terms are only used to distinguish one constituent element from others. For example, without departing from the scope of this invention, a first constituent element may be named a second constituent element, and similarly, a second constituent element may be named a first constituent element.

[0045] In this specification, terms such as "and / or" include a combination of multiple related items or a portion of multiple related items.

[0046] In this specification, when a constituent element is described as singular, it includes multiple instances unless otherwise defined in this specification.

[0047] In this specification, the terms "including" and "possessing" are used to indicate the presence of features, numbers, steps, actions, processes, constituent elements, components, or combinations thereof as described in this specification, unless otherwise expressly stated in this specification, and do not exclude other features, numbers, etc.

[0048] In this manual, "secondary battery" refers to a battery that can be used repeatedly for extended periods through recharging. Secondary batteries are classified according to the active electrode materials, such as nickel-cadmium batteries and lithium-ion batteries. They are also classified according to their shape, such as pouch batteries, square batteries, and cylindrical batteries.

[0049] In this specification, the aforementioned secondary battery includes a battery can housing the electrode assembly. The battery can is cylindrical.

[0050] A cylindrical secondary battery is, for example, a cylindrical secondary battery whose shape factor ratio (defined as the ratio of the diameter of the cylindrical secondary battery to its height, i.e., the ratio of diameter (Φ) to height (H)) is approximately greater than 0.4.

[0051] Here, the shape factor refers to the value representing the diameter and height of a cylindrical secondary battery.

[0052] In this specification, the term "cylindrical secondary battery" refers to a secondary battery with a cylindrical or similar shape. Cylindrical secondary batteries, due to their high energy density per volume, are often used in high-capacity electronic and electronic devices, where multiple batteries are combined to form a battery pack.

[0053] Additionally, the term "cylindrical secondary battery" refers to a structure in which, for example, a rivet inserted through and onto the bottom surface (opposite side) opposite the opening of the cylindrical secondary battery is used as the cathode, and the battery can itself is used as the anode.

[0054] In this specification, the term "cylindrical secondary battery" is used, for example, as 46110 unit, 48750 unit, 48110 unit, 48800 unit, and 46800 unit. In the shape factor values, the first two digits represent the diameter of the unit, the next two digits represent the height of the unit, and the final digit 0 indicates that the unit's cross-section is circular. When the unit height is 100mm or more, a three-digit number is needed to represent the unit height, therefore the final digit 0 can be omitted.

[0055] In addition, the term "first electrode" refers to the anode, and the term "second electrode" refers to the cathode, but it can also be the other way around.

[0056] Furthermore, the battery can, being a generally cylindrical housing with an opening on one side, is made of a conductive metal. The side of the battery can and the opposite side of the opening are typically formed as one piece. That is, the battery can generally has a shape where, based on its height direction, the upper end is open, and the lower end, except for the central portion, is closed. The lower surface of the battery can is generally flat. The battery can houses the electrode assembly through the opening formed on one side in its height direction. The battery can also houses the electrolyte through the opening.

[0057] Unless otherwise defined, all terms used in this specification, including technical or scientific terms, have the same meaning as would be understood by one of ordinary skill in the art in general.

[0058] Hereinafter, with reference to the accompanying drawings, preferred embodiments of the prior art and the present invention will be described in detail.

[0059] Figure 1 This shows a previous type of current collector. Figure 1 (a) is a side view of the current collector. Figure 1 (b) is a top view of the current collector 30. The current collector 30 includes a tab connection portion 32 extending from the center portion 31 to the can connection portion 33 and engaging with the first electrode tab 11; for example, four tab connection portions 32 are shown. The can connection portion 33 of the current collector 30 has a discontinuous outer peripheral surface.

[0060] Figure 2 It is applicable. Figure 1 The illustrated side cross-sectional view of a conventional cylindrical secondary battery with a current collector plate shows that the can joint 33 of the current collector plate 30 extends not only to the rolled edge 21 but also to the crimping portion 22. In this case, a gap is created between the current collector plate 30 and the injection molded material, weakening the sealing structure of the battery can and potentially causing leakage. In other words, with the can joint 33 extending to the crimping portion 22, the airtightness achieved at the crimping portion by the sealing gasket G1 between the top cover 40 and the battery can 20 is weakened.

[0061] According to one embodiment of the present invention, a cylindrical secondary battery is provided, comprising: An electrode assembly has a structure in which a first electrode, a second electrode, and a spacer between them are stacked and wound in sequence. The first electrode has an uncoated portion with no active material on the side of the current collector. The uncoated portion includes a first electrode tab bent from the end of the electrode assembly toward the winding center or the outer contour direction. A battery can housing the aforementioned electrode assembly through an opening formed on one side; A current collector includes three or more tab joints electrically connected to the first electrode tabs, and a can joint having a continuous outer peripheral surface extending from the end of the tab joints toward the opening of the battery can and electrically connected to the inner surface of the battery can; and The top cover covers the open portion of the aforementioned battery canister.

[0062] Regarding the above examples, please refer to... Figure 3 and Figure 4 The first electrode tab 11 is coupled to the tab coupling portion 32 of the current collector plate 30, and the can coupling portion 33 has a continuous outer peripheral surface shape. The current collector plate 30 includes three or more tab coupling portions 32 coupled to the first electrode tab 11 and a can coupling portion 33 having a continuous outer peripheral surface that extends upward from the end of the tab coupling portion 32 and is electrically coupled to the inner surface of the battery can.

[0063] According to the above example, the current collector has a continuous outer peripheral surface, so the connection between the current collector and the battery can is stable.

[0064] According to an additional embodiment of the present invention, a cylindrical secondary battery is provided, wherein the tab joint extends from the center of the current collector plate to the can joint and contacts the first electrode tab respectively.

[0065] Regarding the above examples, please refer to... Figure 3 and Figure 4 The current collector 30 includes a central portion 31 in its core region. The central portion 31 is generally circular in shape. The tab connection portion 32 of the current collector 30 extends from the central portion 31 to the can connection portion 33 in the outer contour direction, and thus connects with the first electrode tab 11.

[0066] The cylindrical secondary battery exemplified above achieves an effective connection between the electrode tabs and the tab junction.

[0067] According to an additional embodiment of the present invention, a cylindrical secondary battery is provided, wherein the angle formed by the aforementioned tab joint and the adjacent other tab joint is 40° or more and 140° or less.

[0068] Regarding the above examples, please refer to... Figure 3 The angle formed by any one of the aforementioned electrode tab joints 32 and the adjacent electrode tab joint is the same or different from each other, and independently forms an angle of 40° or more, 50° or more, 60° or more, 70° or more, 80° or more, or 90° or more. On the other hand, referring to... Figure 3 The angle formed by any one of the aforementioned electrode tab joints 32 and the adjacent electrode tab joint is the same or different from each other, and independently constitutes 140° or less, 130° or less, 120° or less, 110° or less, or 100° or less. On the other hand, referring to... Figure 3 The angle formed by any one of the aforementioned electrode joints 32 and the adjacent electrode joint is 90°.

[0069] The cylindrical secondary battery exemplified above achieves an effective connection between the electrode tabs and the tab junction.

[0070] According to an additional embodiment of the invention, a cylindrical secondary battery is provided, comprising: a rolled edge portion formed at the side end of the battery can adjacent to the aforementioned open portion and pressed inward.

[0071] Based on the above examples, refer to Figure 3 and Figure 4 The battery can 20 includes a rolled edge portion 21 in its open portion (not shown). This rolled edge portion 21 is adjacent to the open portion at the upper end of the battery can 20 and has a shape that is pressed inward. The rolled edge portion 21 is formed on the upper part of the electrode assembly 10. The inner diameter of the battery can 20 in the region where the rolled edge portion 21 is formed is smaller than the diameter of the electrode assembly 10.

[0072] The aforementioned rolled edge 21 refers to the area having a groove bent inwards towards the battery for mounting the sealing gasket G1 on the upper part of the battery can 20. This rolled edge 21 serves to provide a support surface for mounting the sealing gasket G1 and the top cover 40. Additionally, the rolled edge 21 provides a support surface for mounting and engaging at least a portion of the periphery of the current collector 30 (described later). That is, at least a portion of the periphery of the current collector 30 of the present invention and / or the periphery of the top cover 40 of the present invention are mounted on the upper surface of the rolled edge 21.

[0073] For example, in order to stably support at least a portion of the area around the edge of the current collector 30 and / or the area around the edge of the top cover 40, the upper surface of the rolled edge 21 has a shape in which at least a portion extends along a direction substantially parallel to the lower surface of the battery can 20, that is, along a direction substantially perpendicular to the side wall of the battery can 20.

[0074] In the above-described cylindrical secondary battery, the can joint is pressurized by the formation of the rolled edge, thus the current collector is stably fixed inside the battery can.

[0075] According to an additional example, a cylindrical secondary battery is provided, wherein the can joint portion of the current collector is connected to the rolled edge portion and has a structure that presses inward.

[0076] In the above example, the can joint of the current collector plate and the side end of the battery can are pressed in together. Furthermore, this pressing in includes the edge-rolling process.

[0077] Specifically, refer to Figure 3 and Figure 4 The can joint 33 of the current collector plate 30 and the side end of the battery can 20 are pressed inward together. In this way, through the edge rolling process, the current collector plate 30 and the battery can 20 deform together and come into contact. Thus, the battery can 20 comes into contact with the current collector plate 30 without a welding process.

[0078] According to an additional embodiment, a cylindrical secondary battery is provided, which includes: a crimping portion formed between the open portion and the rolled edge portion, extending and bending toward the open portion.

[0079] Regarding the above examples, please refer to... Figure 3 and Figure 4 In the battery can 20 described above, the crimping portion 22 is formed at an upper position than the rolled edge portion 21. That is, the crimping portion 22 is formed at the upper end of the rolled edge.

[0080] The aforementioned crimping portion 22 refers to the area that extends and bends (bending or folding) by applying pressure to the upper part of the rolled edge portion 21, which includes a safety device such as a sealing gasket G1, to surround the edge of the top cover 40 disposed on the upper part of the rolled edge portion 21. With such a shape of crimping portion 22, the top cover 40 is fixed to the rolled edge portion 21.

[0081] On another side, in the radial direction, the innermost portion of the rolled edge 21 is positioned closer to the inside than the end portion of the crimping portion 22. For example, in the radial direction, the end portion of the crimping portion 22 is positioned closer to the outside than the innermost portion of the rolled edge 21. With this structure, the rolled edge 21 can remain flat even after the precision pressing process. If, for example, the innermost portion of the rolled edge 21 is positioned closer to the outside than the end portion of the crimping portion 22 in the radial direction, the upper surface of the crimping portion 22 is longer in the radial direction than the rolled edge 21. In this case, the area subjected to pressure during the precision pressing process, i.e., the area of ​​the upper surface of the crimping portion 22, becomes wider, and thus the rolled edge 21 will not be flat after the precision pressing process. Therefore, preferably, in the present invention, the innermost portion of the rolled edge 21 is positioned closer to the inside than the end portion of the crimping portion 22 in the radial direction.

[0082] The cylindrical secondary battery described above demonstrates a safe seal.

[0083] According to an additional example, a cylindrical secondary battery is provided, wherein the aforementioned can joint is press-fitted and fixed by the aforementioned rolled edge portion.

[0084] Regarding the above examples, please refer to... Figure 3 and Figure 4 When forming the rolled edge portion 21 located on the upper opening side of the battery can, pressure is also applied to the can joint portion 33, so that the current collector 30 is pressed and fixed inside the battery can 20, thereby realizing the electrical connection between the battery can 20 and the current collector 30.

[0085] The cylindrical secondary battery in the above example is fixed by pressing the current collector plate to the battery canister, thus eliminating the welding process and simplifying the manufacturing process of the cylindrical secondary battery.

[0086] According to an additional embodiment, a cylindrical secondary battery is provided, wherein the outer peripheral surface of the can joint extends from the lower end of the rolled edge portion to the lower end of the crimping portion. In other words, the can joint extends to the rolled edge portion but does not extend to the crimping portion.

[0087] Regarding the above examples, please refer to... Figure 4 In the cylindrical secondary battery exemplified above, the current collector 30 extends only to the rolled edge 21 and is not inserted into the crimping part 22.

[0088] In the cylindrical secondary battery exemplified above, there is no gap between the current collector 30 and the injection molded material, thus maintaining the sealed structure of the battery can 20 and preventing the possibility of leakage. In particular, the can joint 33 has a length that does not extend to the crimping portion 22, and is fixed to the crimped portion 21 by crimping pressure.

[0089] According to the additional example, a cylindrical secondary battery is provided, wherein the outer shape of the aforementioned can joint is circular.

[0090] Regarding this, please refer to Figure 3 and Figure 4 The can joint 33 has a circular shape.

[0091] The cylindrical secondary battery exemplified above achieves a stable connection between the current collector plate and the rolled edge portion 21 of the battery canister 20 through the outward repulsion force of the current collector and the bending forming force achieved by the rolled edge of the battery canister 20.

[0092] According to an additional example, a cylindrical secondary battery is provided, wherein the second electrode includes an uncoated portion without active material on the current collector side. The aforementioned uncoated portion includes a second electrode tab bent at the end of the aforementioned electrode assembly toward the winding center or outward profile. On the opposite side of the open portion of the aforementioned battery can, there is a second electrode terminal that is electrically connected to the second electrode tab.

[0093] The cylindrical secondary battery exemplified above can reduce the resistance of the gel roll electrode assembly.

[0094] According to one embodiment of the present invention, a battery pack comprising one of the aforementioned cylindrical secondary batteries is provided.

[0095] Regarding the above examples, Figure 5 The illustration shows a battery pack 3 including a cylindrical secondary battery 1 in the housing 2.

[0096] The battery pack described above has high power / high capacity.

[0097] According to one embodiment of the present invention, a mobile unit comprising the above-described battery pack is provided.

[0098] Regarding the above examples, Figure 6 The illustration shows a movable unit 5 including a battery pack 3.

[0099] The mobile unit described above uses a battery pack with high power and high capacity, thus exhibiting excellent stability and safety.

[0100] In the above-described embodiments, any active material known in the art can be used for the anodic active material coated onto the anode plate and the cathode active material coated onto the cathode plate.

[0101] In one example, the anolyte may include a material with the general chemical formula A[A] x M y ]O 2+zThe represented alkaline metal compound (A includes at least one element selected from Li, Na, and K; M includes at least one element selected from Ni, Co, Mn, Ca, Mg, Al, Ti, Si, Fe, Mo, V, Zr, Zn, Cu, Al, Mo, Sc, Zr, Ru, and Cr; x≥0, 1≤x + y≤2, 0.1≤z≤2; the stoichiometric coefficients x, y, and z are selected in such a way that the compound maintains electrical neutrality).

[0102] In another example, the anode active material can be an alkaline metal compound xLiM disclosed in US6,677,082, US6,680,143, etc. 1 O2(1 - x)Li2M 2 O3(M 1 includes at least one element with an average oxidation state of 3; M 2 includes at least one element with an average oxidation state of 4; 0≤x≤1).

[0103] In yet another example, the anode active material can be of the general chemical formula LiaM 1 x Fe 1x M 2 yP 1y M 3 zO 4z (M 1 includes at least one element selected from Ti, Si, Mn, Co, Fe, V, Cr, Mo, Ni, Nd, Al, Mg, and Al; M 2 includes at least one element selected from Ti, Si, Mn, Co, Fe, V, Cr, Mo, Ni, Nd, Al, Mg, Al, As, Sb, Si, Ge, V, and S; M 3 includes halogen elements that selectively include F; 0 < a≤2, 0≤x≤1, 0≤y < 1, 0≤z < 1; the stoichiometric coefficients a, x, y, and z are selected in such a way that the compound maintains electrical neutrality) or lithium metal phosphate represented by Li3M2(PO4)3 [M includes at least one element selected from Ti, Si, Mn, Fe, Co, V, Cr, Mo, Ni, Al, Mg, and Al].

[0104] Preferably, the anode active material can include primary particles and / or secondary particles aggregated from primary particles.

[0105] In one example, the cathode active material can be carbon, lithium metal or lithium metal compounds, silicon or silicon compounds, tin or tin compounds, etc. Metal oxides such as TiO2 and SnO2 with a potential less than 2V can also be used as cathode active materials. Low-crystallinity carbon and high-crystallinity carbon can be used as carbon materials.

[0106] The interlayer can be a porous polymer film, such as a porous polymer film made of polyolefin polymers such as ethylene monomer polymers, propylene monomer polymers, ethylene / butene copolymers, ethylene / hexene copolymers, and ethylene / methacrylate copolymers, used alone or in layers. Alternatively, the interlayer can be a conventional porous nonwoven fabric, such as a nonwoven fabric made of high-melting-point glass fiber or polyethylene terephthalate fiber.

[0107] At least one surface of the interlayer may include a coating of inorganic particles. Furthermore, the interlayer itself may be composed of a coating of inorganic particles. The particles constituting the coating may have a structure bonded to an adhesive, resulting in interstitial volume between adjacent particles.

[0108] Inorganic particles can be composed of inorganic materials with a dielectric constant of 5 or higher. As a non-limiting example, the aforementioned inorganic particles may include those selected from Pb(Zr,Ti)O3 (PZT), Pb... 1x La x Zr 1y Ti y O3 (PLZT), PB (Mg3Nb) 2 / 3 At least one substance in the group consisting of O3PbTiO3 (PMNPT), BaTiO3, hafnia (HfO2), SrTiO3, TiO2, Al2O3, ZrO2, SnO2, CeO2, MgO, CaO, ZnO and Y2O3.

[0109] In the above example, the cylindrical secondary battery includes an electrolyte. The electrolyte may be a electrolyte having A... + B - Salts with similar structures. Among them, A... + Including Li + Na + K + Ions consisting of basic metal cations or combinations thereof. Additionally, B... - Including the choice of F - Cl - ,Br - I - NO3 - N(CN)2 - BF4- ClO4 - AlO4 - AlCl4 - PF6 - SbF6 - AsF6 - BF2C2O4 - BC4O8 - (CF3)2PF4 - (CF3)3PF3 - (CF3)4PF2 - (CF3) 5PF - (CF3) 6P - CF3SO3 - C4F9SO3, CF3CF2SO3 - (CF3SO2)2N - (FSO2)2N - CF3CF2(CF3)2CO - (CF3SO2)2CH - (SF5) 3C - (CF3SO2)3C - CF3(CF2)7SO3 - CF3CO2 - CH3CO2, SCN - and (CF3CF2SO2)2N - Any one or more anions that constitute a group.

[0110] Electrolytes can also be used in organic solvents. Suitable organic solvents include propylene carbonate (PC), ethylene carbonate (EC), diethyl carbonate (DEC), dimethyl carbonate (DMC), dipropyl carbonate (DPC), dimethyl sulfoxide, acetonitrile, dimethoxyethane, diethoxyethane, tetrahydrofuran, N-methyl-pyrrolidone (NMP), ethyl methyl carbonate (EMC), γ-butyrolactone, or mixtures thereof.

[0111] The preferred embodiments of the present invention have been described above, but the present invention is not limited thereto. Various modifications can be made within the scope of the claims and the detailed description of the invention, which also fall within the scope of the invention.

Claims

1. A cylindrical secondary battery, the cylindrical secondary battery comprising: An electrode assembly having a structure in which a first electrode, a second electrode, and a spacer between the first electrode and the second electrode are sequentially stacked and wound up, wherein the first electrode includes an uncoated portion on one side of the current collector that is not coated with active material, and the uncoated portion includes a first electrode tab bent from the end of the electrode assembly toward the winding center or the outer contour direction. A battery canister configured to house the electrode assembly via an opening formed on one side of the battery canister; A current collector includes three or more tab connections electrically connected to the first electrode tabs. The tab connections are disposed on the side of the open portion of the battery can opposite to the electrode assembly. The current collector also includes a can connection connected to the ends of the three or more tab connections. The can connection extends from the ends of the tab connections toward the open portion of the battery can and is electrically connected to the inner surface of the battery can. The can connection has a continuous outer peripheral surface. A top cover, configured to cover the opening of the battery canister.

2. The cylindrical secondary battery according to claim 1, wherein, The electrode tab connection extends from the center of the current collector plate to the can connection and contacts the first electrode tab.

3. The cylindrical secondary battery according to claim 1, wherein, The angle between adjacent tab joints is greater than 40° and less than 140°.

4. The cylindrical secondary battery according to claim 1, wherein the cylindrical secondary battery comprises: A rolled edge portion, the rolled edge portion having a structure that is pressed inward and formed at the side end of the battery can adjacent to the open portion.

5. The cylindrical secondary battery according to claim 4, wherein, The can joint portion of the current collector plate has a structure that presses inward and is connected to the rolled edge portion.

6. The cylindrical secondary battery according to claim 5, wherein, The cylindrical secondary battery includes: A crimping portion is formed between the open portion and the rolled edge portion and extends toward and bends toward the open portion.

7. The cylindrical secondary battery according to claim 6, wherein, The can joint is pressed and fixed by the rolled edge portion.

8. The cylindrical secondary battery according to claim 6, wherein, The outer peripheral surface of the can joint extends from the lower end of the rolled edge portion to the lower end of the crimped portion.

9. The cylindrical secondary battery according to claim 1, wherein, The outer diameter portion of the tank joint has a circular shape.

10. The cylindrical secondary battery according to claim 1, wherein, The second electrode includes: The uncoated portion on one side of the current collector, where no active material is applied, includes a second electrode tab bent along a direction from the end of the electrode assembly to the winding center or outer contour; and A second electrode terminal is provided on the side opposite to the opening of the battery can and is electrically connected to the second electrode tab.

11. A battery pack comprising a cylindrical secondary battery according to any one of claims 1 to 10.

12. A mobile unit comprising the battery pack according to claim 11.

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