Electrode assembly and secondary battery including same

Abstract

The present invention provides an electrode assembly and a secondary battery including same. The electrode assembly includes: a first electrode including a first base layer and first mixture layers coated on both surfaces of the first base layer; a second electrode including a second base layer and a third base layer, an insulating layer disposed between the second base layer and the third base layer, a second mixture layer coated on the second base layer, and a third mixture layer coated on the third base layer; and a separator disposed between the first electrode and the second electrode, wherein the insulating layer may extend from one side surface of each of the second base layer and the third base layer to be exposed.

Description

Electrode assembly and secondary battery including the same

[0001] The present invention relates to an electrode assembly and a secondary battery including the same.

[0002] The recent rapid proliferation of battery-powered electronic devices, such as mobile phones, laptops, and electric vehicles, has led to a rapid increase in demand for high-energy-density, high-capacity secondary batteries. Lithium secondary batteries, among others, comprise positive and negative electrodes containing active materials capable of lithium ion intercalation and deintercalation, as well as an electrolyte. They generate electrical energy through oxidation and reduction reactions that occur when lithium ions intercalate and deintercalate at the positive and negative electrodes.

[0003] Typically, lithium secondary batteries are manufactured by inserting a wound or laminated electrode assembly into a case, with a separator positioned between the positive and negative electrodes. If the electrode assembly deforms during use, the positive and negative electrodes may come into contact with each other, resulting in a short circuit.

[0004] The above-described information disclosed in the background technology of this invention is only intended to improve understanding of the background of the present invention, and therefore may include information that does not constitute prior art.

[0005] The problem to be solved by the present invention is to provide an electrode assembly and a secondary battery including the same for solving the above-mentioned problems.

[0006] However, the technical problems to be solved by the present invention are not limited to the problems described above, and other problems not mentioned can be clearly understood by those skilled in the art from the description of the invention described below.

[0007] According to some embodiments of the present invention for solving the above technical problem, an electrode assembly includes a first electrode including a first substrate layer and a first mixture layer coated on both sides of the first substrate layer, a second substrate layer and a third substrate layer, an insulating layer disposed between the second substrate layer and the third substrate layer, a second electrode including a second mixture layer coated on the second substrate layer and a third mixture layer coated on the third substrate layer, and a separator disposed between the first electrode and the second electrode, wherein the insulating layer can be extended and exposed from one side of the second substrate layer and the third substrate layer.

[0008] According to some embodiments of the present invention, the insulating layer may include polyethylene terephthalate (PET).

[0009] According to some embodiments of the present invention, at least a portion of the second substrate layer may include a plain portion on which the second composite layer is not coated, and at least a portion of the third substrate layer may include a plain portion on which the third composite layer is not coated.

[0010] According to some embodiments of the present invention, a first electrode, a separator disposed on the first electrode, and a second electrode disposed on the separator are formed by being wound around a core portion, and a length of an imaginary curve extending from a first end positioned close to the core portion of the second substrate layer and a third substrate layer to a position parallel to a second end positioned close to the core portion of the first substrate layer in the same shape as the second electrode is wound may be longer than the shortest distance from the core portion to the first electrode.

[0011] According to some embodiments of the present invention, a first electrode, a separator disposed on the first electrode, and a second electrode disposed on the separator are formed by being wound around a core portion, the first substrate layer includes a first upper plain portion exposed to the outside of the first composite layer in the axial direction of the core portion, and the first upper plain portion may include a plurality of first segments formed by notching at least a portion of the first upper plain portion.

[0012] According to some embodiments of the present invention, a first electrode, a separator disposed on the first electrode, and a second electrode disposed on the separator are formed by being wound around a core portion, the second substrate layer includes a second upper plain portion exposed to the outside of the second composite layer in the axial direction of the core portion, the third substrate layer includes a third upper plain portion combined with the second upper plain portion and exposed to the outside of the third composite layer in the axial direction of the core portion, and the second upper plain portion and the third upper plain portion may include a plurality of second segments formed by at least a portion being notched while combined.

[0013] According to some embodiments of the present invention, the area of ​​the insulating layer may be larger than the area of ​​the second substrate layer.

[0014] According to some embodiments of the present invention, the electrode assembly is formed by winding a first electrode, a separator, and a second electrode, and the width of the insulating layer in the exposed section of the insulating layer may be greater than or equal to the width of the second substrate layer and the width of the third substrate layer.

[0015] According to some embodiments of the present invention, the insulating layer may include a first exposed portion exposed in one width direction of the second substrate layer and the third substrate layer in the exposed section.

[0016] According to some embodiments of the present invention, the exposure section may be located at the core-side end of the electrode assembly.

[0017] According to some embodiments of the present invention, the second electrode includes a second uncoated portion on which the second composite layer is not applied on the multilayer substrate, and the second uncoated portion can be positioned in an opposite direction to the first exposed portion.

[0018] According to some embodiments of the present invention, a second substrate tab may be formed on at least a portion of the second non-conductive portion.

[0019] According to some embodiments of the present invention, the first electrode includes a first uncoated portion on which the first composite layer is not applied, and a first substrate tab may be formed on at least a portion of the first uncoated portion.

[0020] According to some embodiments of the present invention, the first substrate tab can be bent toward the winding direction of the electrode assembly.

[0021] According to some embodiments of the present invention for solving the above technical problem, a secondary battery includes an electrode assembly according to the embodiments described above, a current collector plate disposed on one surface of the electrode assembly, a case housing the electrode assembly, and an insulating tape disposed between the electrode assembly and the current collector plate, wherein the insulating tape may include a body portion that insulates between a core portion of the electrode assembly and the current collector plate, and a leg portion that extends from the body portion and is interposed between an outer surface of the electrode assembly and the case.

[0022] According to some embodiments of the present invention, at least a portion of the first non-conductive portion is bent along the radial direction of the electrode assembly to form a substrate tab, the substrate tab includes a welding portion for welding with a current collector, and the body of the insulating tape can be disposed in an area of ​​the substrate tab excluding the welding portion.

[0023] According to some embodiments of the present invention, the body of the insulating tape may be a ring shape having an outer diameter of 5 mm to 20 mm centered around the central hole.

[0024] According to some embodiments of the present invention, the core portion of the electrode assembly includes a through hole, and the central hole of the body portion can be positioned at a position corresponding to the through hole.

[0025] According to some embodiments of the present invention, the body portion of the insulating tape may be positioned to cover the notch of the current collector plate.

[0026] According to some embodiments of the present invention, the bridge portion may include two or more rods, and two of the two or more rods may be formed to face each other.

[0027] According to some embodiments of the present invention for solving the above technical problem, an electrode assembly includes a first electrode including a first substrate layer and a first mixture layer coated on both sides of the first substrate layer, a second substrate layer and a third substrate layer, an insulating layer disposed between the second substrate layer and the third substrate layer, a second electrode including a second mixture layer coated on the second substrate layer and a third mixture layer coated on the third substrate layer, and a separator disposed between the first electrode and the second electrode, wherein the insulating layer can be extended and exposed from one side of the second substrate layer and the third substrate layer.

[0028] According to some embodiments of the present invention, the insulating layer may include polyethylene terephthalate (PET).

[0029] According to some embodiments of the present invention, the thickness of the insulating layer may be greater than the thickness of each of the second substrate layer and the third substrate layer.

[0030] According to some embodiments of the present invention, at least a portion of the second substrate layer may include a plain portion on which the second composite layer is not coated, and at least a portion of the third substrate layer may include a plain portion on which the third composite layer is not coated.

[0031] According to some embodiments of the present invention, a first electrode, a separator disposed on the first electrode, and a second electrode disposed on the separator may be formed by winding around a core.

[0032] According to some embodiments of the present invention, the length of an imaginary curve extending from a first tip positioned close to the core of the second substrate layer and the third substrate layer to a position parallel to the second tip positioned close to the core of the first substrate layer in a shape similar to the shape in which the second electrode is wound may be longer than the shortest distance from the core to the first electrode.

[0033] According to some embodiments of the present invention, the area of ​​the insulating layer may be larger than the area of ​​the second substrate layer.

[0034] According to some embodiments of the present invention, a first electrode, a separator disposed on the first electrode, and a second electrode disposed on the separator are formed by being wound around a core portion, the first substrate layer includes a first upper plain portion exposed to the outside of the first composite layer in the axial direction of the core portion, and the first upper plain portion may include a plurality of first segments formed by notching at least a portion of the first upper plain portion.

[0035] According to some embodiments of the present invention, a first electrode, a separator disposed on the first electrode, and a second electrode disposed on the separator are formed by being wound around a core portion, the second substrate layer includes a second upper plain portion exposed to the outside of the second composite layer in the axial direction of the core portion, the third substrate layer includes a third upper plain portion combined with the second upper plain portion and exposed to the outside of the third composite layer in the axial direction of the core portion, and the second upper plain portion and the third upper plain portion may include a plurality of second segments formed by being notched in a combined state.

[0036] According to some embodiments of the present invention, the first electrode may be a cathode and the second electrode may be an anode.

[0037] According to some embodiments of the present invention for solving the above technical problem, a secondary battery includes an electrode assembly including a first electrode, a second electrode, and a separator disposed between the first electrode and the second electrode, a case including a bottom portion electrically connected to the first electrode, a side wall portion connected to the bottom portion, and an opening facing the bottom portion, the case accommodating the electrode assembly through the top opening, and a cap assembly sealing the top opening of the case, wherein the first electrode includes a first substrate layer and a first mixture layer coated on both sides of the first substrate layer, and the second electrode includes a second substrate layer and a third substrate layer, an insulating layer disposed between the second substrate layer and the third substrate layer, a second mixture layer coated on the second substrate layer, and a third mixture layer coated on the third substrate layer, wherein the insulating layer can be extended and exposed from one side of the second substrate layer and the third substrate layer.

[0038] According to one embodiment of the present invention for solving the above technical problem, an electrode assembly is formed by winding a first electrode, a separator, and a second electrode, wherein the first electrode includes a first multilayer substrate in which a first substrate layer, a first insulating layer, and a second substrate layer are laminated, and a width of the first insulating layer in an exposed section of the first insulating layer may be greater than or equal to the width of the first substrate layer and the width of the second substrate layer.

[0039] According to one embodiment of the present disclosure, the first insulating layer may include a first exposed portion exposed in one width direction of the first substrate layer and the second substrate layer in the exposed section.

[0040] According to one embodiment of the present disclosure, the height of the first exposed portion may be from 1.5 mm to 2.5 mm.

[0041] According to one embodiment of the present disclosure, the height of the first exposed portion may be 2% to 5% of the width length of the first multilayer substrate.

[0042] According to one embodiment of the present disclosure, the exposure section may be located at the core-side end of the electrode assembly.

[0043] According to one embodiment of the present disclosure, the length of the exposure section may be 1% to 1.5% of the length of the multilayer substrate.

[0044] According to one embodiment of the present disclosure, the first electrode includes a first uncoated portion on which a first composite layer is not applied on a multilayer substrate, and the first uncoated portion can be positioned in an opposite direction to the first exposed portion.

[0045] According to one embodiment of the present disclosure, a first substrate tab may be formed on at least a portion of the first non-conductive portion.

[0046] According to one embodiment of the present disclosure, the second electrode includes a second non-coated portion on which the second composite layer is not applied, and a second substrate tab may be formed on at least a portion of the second non-coated portion.

[0047] According to one embodiment of the present disclosure, the second substrate tab can be bent toward the core direction of the electrode assembly.

[0048] According to one embodiment of the present disclosure, the thickness of the first substrate layer or the second substrate layer may be 1 mm to 2 mm.

[0049] According to one embodiment of the present disclosure, the thickness of the first insulating layer may be from 4 mm to 8 mm.

[0050] According to one embodiment of the present disclosure, the length of the first insulating layer may be greater than or equal to the length of the first substrate layer or the second substrate layer.

[0051] A method for manufacturing an electrode assembly according to one embodiment of the present invention for solving a technical problem includes a step of manufacturing a first multilayer substrate by laminating a first substrate layer, a first insulating layer, and a second substrate layer, and a step of winding a first electrode, a separator, and a second electrode including the first multilayer substrate, wherein the width of the first insulating layer in an exposed section of the first insulating layer of the first electrode may be greater than or equal to the width of the first substrate layer or the width of the second substrate layer.

[0052] A method for manufacturing an electrode assembly according to one embodiment of the present disclosure may further include a step of manufacturing a first electrode by applying a first composite layer on a multilayer substrate.

[0053] According to one embodiment of the present disclosure, the second electrode includes a second uncoated portion on which a second composite layer is not applied, and the method for manufacturing the electrode assembly may further include a step of forming a second substrate tab on the second uncoated portion before the step of winding the first electrode, separator, and second electrode including the multilayer substrate.

[0054] According to one embodiment of the present disclosure, the step of forming a substrate tab on the second non-woven portion may include the step of welding and attaching a metal substrate to the second non-woven portion and the step of notching the metal substrate.

[0055] A method for manufacturing an electrode assembly according to one embodiment of the present disclosure may further include a step of bending a substrate tab.

[0056] A secondary battery according to one embodiment of the present invention for solving a technical problem may include an electrode assembly according to one embodiment of the present invention, a case housing the electrode assembly, and a vent plate sealing one side opening of the case.

[0057] According to one embodiment of the present invention for solving the above technical problem, a secondary battery includes an electrode assembly formed by stacking and winding a first electrode, a separator, and a second electrode, a current collector plate disposed on one surface of the electrode assembly, a case housing the electrode assembly, and an insulating tape disposed between the electrode assembly and the current collector plate, wherein the insulating tape may include a body portion that insulates between a core portion of the electrode assembly and the current collector plate, and a leg portion that extends from the body portion and is interposed between an outer surface of the electrode assembly and the case.

[0058] According to one embodiment of the present disclosure, a first electrode includes a first active material portion coated with a first active material along a winding direction and a first non-coated portion not coated with the first active material, the first non-coated portion includes a plurality of independently bendable segments, and the plurality of segments can be bent along a radial direction of the electrode assembly to form an electrode tab.

[0059] According to one embodiment of the present disclosure, the electrode tab includes a welding portion for welding with a current collector, and the body of the insulating tape can be placed in an area of ​​the electrode tab excluding the welding portion.

[0060] According to one embodiment of the present disclosure, the segments of the electrode assembly can be formed around the core portion.

[0061] According to one embodiment of the present disclosure, the body of the insulating tape may have a ring shape having an outer diameter of 5 mm to 20 mm centered on the central hole.

[0062] According to one embodiment of the present disclosure, the core portion of the electrode assembly includes a through hole, and the central hole of the body portion can be positioned at a position corresponding to the through hole.

[0063] According to one embodiment of the present disclosure, the body portion of the insulating tape may be positioned to cover the notch of the current collector plate.

[0064] According to one embodiment of the present disclosure, the bridge portion includes two or more rods, and two of the two or more rods may be formed to face each other.

[0065] According to one embodiment of the present disclosure, the width of each of the two or more rods may be from 1 mm to 10 mm.

[0066] According to one embodiment of the present disclosure, the length of each of the two or more rods may be from 1 mm to 115 mm.

[0067] A secondary battery according to one embodiment of the present disclosure may further include an insulating member disposed on one side of the electrode assembly opposite to the other side on which the insulating tape is disposed.

[0068] According to one embodiment of the present disclosure, one side of the body portion facing the collector plate may be coated with an adhesive layer.

[0069] According to one embodiment of the present disclosure, the diameter of the case may be 40 mm to 50 mm.

[0070] A method for manufacturing a secondary battery according to an embodiment of the present invention for solving a technical problem includes the steps of forming an electrode assembly by stacking and then winding a first electrode, a separator, and a second electrode, the step of arranging an insulating tape on one side of the electrode assembly, the step of arranging a current collector on the insulating tape, and the step of inserting the electrode assembly, the insulating tape, and the current collector through an opening on one side of the case and embedding them in the case, wherein the insulating tape may include a body portion that insulates between a core portion of the electrode assembly and the current collector, and a leg portion that extends from the body portion and is interposed between an outer peripheral surface of the electrode assembly and the case.

[0071] According to one embodiment of the present disclosure, the step of placing the collector plate may include the step of welding the collector plate and the electrode assembly.

[0072] According to one embodiment of the present disclosure, the first electrode includes a first active material portion coated with a first active material along a winding direction and a first non-coated portion not coated with the first active material, the first non-coated portion includes a plurality of independently bendable segments, and the step of forming the electrode assembly may include a step of bending the plurality of segments along a radial direction of the electrode assembly to form an electrode tab.

[0073] According to one embodiment of the present disclosure, the electrode tab includes a welding portion for welding with a current collector, and the body of the insulating tape can be placed in an area of ​​the electrode tab excluding the welding portion.

[0074] According to one embodiment of the present disclosure, the body of the insulating tape has a ring shape with an outer diameter of 5 mm to 20 mm centered on a central hole, the core of the electrode assembly includes a through hole, and the step of placing the insulating tape may include a step of placing the central hole of the body at a position corresponding to the through hole.

[0075] According to one embodiment of the present disclosure, the step of placing the collector plate may include the step of placing the collector plate such that the body portion of the insulating tape covers the notch of the collector plate.

[0076] A method for manufacturing a secondary battery according to one embodiment of the present disclosure may further include a step of inserting a welding rod through a through hole included in a core portion of an electrode assembly and a central hole included in a body portion of an insulating tape.

[0077] According to some embodiments of the present invention, by arranging an insulating layer between the substrate layers constituting the electrode assembly of a secondary battery, the weight and amount of metal used are reduced compared to when a single substrate layer is used, thereby reducing the manufacturing cost of the secondary battery and improving the energy density per unit weight. Furthermore, even if damage occurs, such as penetration of a portion of the case or electrode assembly of the secondary battery by the insulating layer, the occurrence of a short circuit is effectively controlled, thereby improving the stability and lifespan characteristics of the secondary battery.

[0078] According to some embodiments of the present invention, the insulating layer of the electrode is exposed by extending from the substrate layer, thereby preventing contact between the electrodes even if deformation of the electrode assembly occurs, thereby preventing short circuits.

[0079] According to some embodiments of the present invention, the overlapping amount of the substrate layer of the electrode in the electrode assembly can be increased, thereby improving the welding conditions of the current collector plate connected to the electrode.

[0080] According to some embodiments of the present disclosure, even if expansion of the positive or negative electrode occurs due to charging and discharging of the electrode assembly, the multilayer substrate can prevent the occurrence of a short circuit by preventing contact between the positive and negative electrodes through an insulating layer in the exposed section.

[0081] According to some embodiments of the present disclosure, an electrode assembly including a multilayer substrate has improved energy density per weight and can store the same energy while having an insulating layer between two substrate layers that is less expensive to manufacture than a metal substrate, thereby improving material cost.

[0082] An electrode assembly comprising a multilayer substrate according to some embodiments of the present disclosure has a low possibility of ignition due to short circuits in penetration or collision of cells, and can advantageously secure welding conditions of a current collector due to increased overlapping of the substrate layers.

[0083] According to some embodiments of the present disclosure, by placing an insulating tape between the electrode assembly and the current collector plate, a short circuit that may occur as the tip of the electrode assembly expands as the secondary battery is charged and discharged can be prevented.

[0084] According to some embodiments of the present disclosure, the stability and lifespan of a secondary battery can be increased by providing an insulating tape designed to be fixed at a location where a short circuit may occur.

[0085] According to some embodiments of the present disclosure, at least a portion of the insulating tape is positioned to cover a notch formed in the current collector plate to protect the electrode assembly from the external environment and prevent corrosion of the notch, thereby preventing failure of the secondary battery.

[0086] However, the effects that can be obtained through the present invention are not limited to the effects described above, and other technical effects that are not mentioned can be clearly understood by those skilled in the art from the description of the invention described below.

[0087] The following drawings attached to this specification illustrate preferred embodiments of the present invention, and together with the detailed description of the invention described below, serve to further understand the technical idea of ​​the present invention, and therefore, the present invention should not be interpreted as being limited to matters described in such drawings.

[0088] FIG. 1 is a drawing showing an electrode assembly according to one embodiment of the present invention.

[0089] FIG. 2 is a drawing showing a cross-section of a second electrode according to one embodiment of the present invention.

[0090] FIG. 3 is a drawing showing an electrode assembly according to one embodiment of the present invention.

[0091] FIG. 4 is a drawing showing an electrode assembly according to one embodiment of the present invention.

[0092] FIG. 5 is a drawing showing a first electrode and a second electrode according to one embodiment of the present invention.

[0093] Figure 6 is a drawing showing a secondary battery according to one embodiment of the present invention.

[0094] FIG. 7 is a schematic drawing of an electrode assembly according to one embodiment of the present disclosure.

[0095] FIG. 8 is a plan view showing a cross-section of a portion of an electrode assembly according to one embodiment of the present disclosure.

[0096] FIG. 9 is a plan view showing a cross-section of an electrode assembly before and after expansion according to one embodiment of the present disclosure.

[0097] FIG. 10 is a drawing illustrating one end of an electrode assembly according to one embodiment of the present disclosure.

[0098] FIG. 11 is a drawing illustrating one end of an electrode assembly according to one embodiment of the present disclosure.

[0099] FIG. 12 is a drawing illustrating a part of a second electrode according to one embodiment of the present disclosure.

[0100] FIG. 13 is a drawing showing a cross-section of a second electrode according to one embodiment of the present disclosure.

[0101] FIG. 14 is a schematic diagram illustrating an appearance of a pre-coiling electrode assembly according to one embodiment of the present disclosure.

[0102] FIG. 15 is a plan view illustrating a cross-section of an electrode assembly after winding according to one embodiment of the present disclosure.

[0103] Figure 16 is a flowchart showing an example of a method for manufacturing a secondary battery according to the present disclosure.

[0104] Figure 17 is a flowchart illustrating a method for manufacturing an electrode assembly according to one embodiment of the present invention.

[0105] FIGS. 18 to 23 are drawings showing a method for manufacturing an electrode assembly according to one embodiment of the present invention.

[0106] FIG. 24 and FIG. 25 are schematic diagrams showing examples of secondary batteries according to one embodiment of the present disclosure.

[0107] FIG. 26 is a cross-sectional view showing a portion of an electrode assembly according to one embodiment of the present disclosure.

[0108] FIG. 27 is a plan view showing one side of an electrode assembly according to one embodiment of the present disclosure.

[0109] Fig. 28 is a perspective view showing an insulating tape and a collector plate according to one embodiment of the present disclosure.

[0110] FIG. 29 is a plan view showing an insulating tape and a current collector plate according to one embodiment of the present disclosure.

[0111] FIG. 30 is a cross-sectional view showing an example of a secondary battery according to one embodiment of the present disclosure.

[0112] Figure 31 is a flowchart showing an example of a method for manufacturing a secondary battery according to the present disclosure.

[0113] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. Prior to this, terms or words used in this specification and claims should not be interpreted as limited to their typical or dictionary meanings, and should be interpreted with meanings and concepts that conform to the technical spirit of the present invention based on the principle that the inventor can appropriately define the concept of a term to best explain his or her own invention. Therefore, the embodiments described in this specification and the configurations illustrated in the drawings are only some of the most preferred embodiments of the present invention and do not represent all of the technical spirit of the present invention. Therefore, it should be understood that various equivalents and modified examples may exist as substitutes for them at the time of filing this application.

[0114] Additionally, when used herein, the terms "comprise", "include" and / or "comprising", "including" specify the presence of stated features, numbers, steps, operations, elements, elements and / or groups thereof, but do not preclude the presence or addition of one or more other features, numbers, operations, elements, elements and / or groups thereof.

[0115] Additionally, to facilitate understanding of the invention, the attached drawings are not drawn to scale and some components may be exaggerated in size. Furthermore, identical components may be assigned the same reference numbers in different embodiments.

[0116] The statement that two compared objects are "identical" means "substantially identical." Therefore, "substantially identical" may include deviations considered low in the art, such as deviations of less than 5%. Furthermore, uniformity of a parameter over a given region may imply uniformity on average.

[0117] Although terms like "first" and "second" are used to describe various components, these components are not limited by these terms. These terms are used merely to distinguish one component from another, and unless otherwise specified, a "first" component may also be a "second" component.

[0118] Throughout the specification, unless otherwise specifically stated, each element may be singular or plural.

[0119] Any configuration being placed "on (or under)" or "above (or below)" a component may mean not only that any configuration is placed in contact with the upper surface (or lower surface) of said component, but also that other configurations may intervene between said component and any configuration placed on (or below) said component.

[0120] Additionally, when it is described that a component is "connected," "coupled," or "connected" to another component, it should be understood that the components may be directly connected or connected to one another, but that other components may also be "interposed" between the components, or that each component may be "connected," "coupled," or "connected" through another component. Furthermore, when it is said that a part is electrically coupled to another part, this includes not only cases where they are directly connected, but also cases where they are connected with another element in between.

[0121] When reference is made throughout the specification to "A and / or B," this means A, B, or A and B, unless otherwise stated. In other words, "and / or" includes all or any combination of the listed items. When reference is made to "C through D," this means C or more and D or less, unless otherwise stated.

[0122] The terminology used herein is for the purpose of describing embodiments of the invention and is not intended to limit the invention.

[0123] In the present invention, the sizes and relative sizes of layers and regions depicted in the drawings may be exaggerated for clarity of explanation. In other words, the sizes depicted in the drawings are for convenience of understanding and are not limited thereto. Furthermore, the same reference numerals designate the same components throughout the specification.

[0124] FIG. 1 is a drawing showing an electrode assembly (100) according to one embodiment of the present invention. Referring to FIG. 1, the electrode assembly (100) may include a first electrode (110), a second electrode (120), and a separator (130) disposed between the first electrode (110) and the second electrode (120). Here, the first electrode (110) may include a first substrate layer (112) and a first composite layer (114) coated on both sides of the first substrate layer (112). In addition, the second electrode (120) may include a second substrate layer (121) and a third substrate layer (122), an insulating layer (123) disposed between the second substrate layer (121) and the third substrate layer (122), a second composite layer (124) coated on the second substrate layer (121), and a third composite layer (125) coated on the third substrate layer (122). The first electrode (110) of the electrode assembly (100) may serve as a cathode, and the second electrode (120) may serve as an anode. Of course, the opposite is also possible.

[0125] In one embodiment, the first substrate layer (112) of the first electrode (110) may be formed of a metal foil such as copper, a copper alloy, nickel, or a nickel alloy. The first composite layer (114) may be formed of graphite, carbon, or the like. The first electrode (110) may include a non-coated region, which is an area where the first composite layer (114) is not applied.

[0126] In one embodiment, the second substrate layer (121) and the third substrate layer (122) of the second electrode (120) may be formed of a metal foil such as aluminum or an aluminum alloy. The second composite layer (124) and the third composite layer (125) may be formed of a transition metal oxide, etc. The second electrode (120) may include a non-coated region, which is a region where the second composite layer (124) and the third composite layer (125) are not applied. The insulating layer (123) is disposed between the second substrate layer (121) and the third substrate layer (122), and may be formed of an insulating material or polymer such as polyethylene terephthalate (PET), polypropylene (PP), polyethylene (PE), polystyrene (PS), polyimide (PI), and polyurethane (PU). The insulating layer (123) can be exposed by extending from one side of the second substrate layer (121) and the third substrate layer (122). Even if deformation of the electrode assembly (100) occurs due to the exposure of the insulating layer (123), contact between the first electrode (110) and the second electrode (120) is prevented, thereby preventing a short circuit.

[0127] In one embodiment, the electrode assembly (100) may be formed by winding a first electrode (110), a separator (130) disposed on the first electrode (110), and a second electrode (120) disposed on the separator (130) around a core. Here, a length (L) of an imaginary curve extending from a first tip (P1) positioned close to the core of the second substrate layer (121) and the third substrate layer (122) to a position parallel to a second tip (P2) positioned close to the core of the first substrate layer (112) in the same shape as the second electrode (120) is wound may be longer than the shortest distance (R) from the core to the first electrode (110). Since the first terminal (P1) and the second terminal (P2) are spaced apart by a certain distance or more, even if deformation of the electrode assembly (100) occurs or the first electrode (110) expands, contact between the first electrode (110) and the second electrode (120) is prevented, thereby preventing a short circuit.

[0128] FIG. 2 is a drawing showing a cross-section of a second electrode according to one embodiment of the present invention. Referring to FIG. 2, the second electrode (120) may include a so-called multilayer substrate or composite substrate, which includes a second substrate layer (121) and a third substrate layer (122) formed of a conductive metal material, and an insulating layer (123) disposed between the second substrate layer (121) and the third substrate layer (122). The "multilayer substrate" or "composite substrate" disclosed in the present invention may refer to a substrate of an electrode for a secondary battery having a structure in which a non-metallic layer or an insulating layer is included between two substrate layers or metal layers, as described above, or in which a plurality of layers or thin films having different materials or properties are laminated. The second electrode (120) may further include a second mixture layer (124) coated on the second substrate layer (121) and a third mixture layer (125) coated on the third substrate layer (122).

[0129] According to some embodiments of the present invention, the second electrode (120) may be an anode. At this time, the conductive metal material forming the second substrate layer (121) and the third substrate layer (122) may include a foil made of a conductive metal material such as aluminum or an aluminum alloy. The insulating layer (123) may be formed of an insulating material or polymer such as polyethylene terephthalate (PET), polypropylene (PP), polyethylene (PE), polystyrene (PS), polyimide (PI), and polyurethane (PU).

[0130] According to some embodiments of the present invention, when the second electrode (120) functions as an anode, the mass of the insulating layer (123) may be greater than the mass of the conductive metal material, such as aluminum, forming the second substrate layer (121) and the third substrate layer (122). Alternatively or additionally, the thickness (T1) of the insulating layer (123) may be greater than the thickness (T2) of the conductive metal material, such as aluminum, forming the second substrate layer (121) and the thickness (T3) of the conductive metal material, such as aluminum, forming the third substrate layer (122).

[0131] According to some embodiments of the present invention, the second mixture layer (124) may be applied on the second substrate layer (121), and the third mixture layer (125) may be applied on the third substrate layer (122). The second mixture layer (124) and the third mixture layer (125) may form a coating portion of the second electrode (120). The second mixture layer (124) and the third mixture layer (125) may include a transition metal oxide, etc.

[0132] According to some embodiments of the present invention, the second electrode (120) may further include a non-coated portion on which no composite layer is applied on both the second substrate layer (121) and the third substrate layer (122) at any position or area along the longitudinal direction of the second electrode (120).

[0133] FIG. 3 and FIG. 4 are drawings showing an electrode assembly (101, 102, 103, 104) according to one embodiment of the present invention.

[0134] Referring to the first example (300a) of FIG. 3, the electrode assembly (101) may include a first electrode (110), a second electrode (120), and a separator (130) disposed between the first electrode (110) and the second electrode (120). The first electrode (110) may include a first substrate layer (112) and a first composite layer (114) coated on both sides of the first substrate layer (112). The second electrode (120) may include a second substrate layer (121) and a third substrate layer (122), an insulating layer (123) disposed between the second substrate layer (121) and the third substrate layer (122), a second composite layer (124) coated on the second substrate layer (121), and a third composite layer (125) coated on the third substrate layer (122). The first electrode (110) of the electrode assembly (101) can serve as a cathode, and the second electrode (120) can serve as an anode.

[0135] At least a portion of the first substrate layer (112) of the first electrode (110) may include a non-coated portion (116) on which the first composite layer (114) is not coated. At least a portion of the second substrate layer (121) of the second electrode (120) may include a non-coated portion (126) on which the second composite layer (124) is not coated, and at least a portion of the third substrate layer (122) of the second electrode (120) may include a non-coated portion (127) on which the third composite layer (125) is not coated. Here, the insulating layer (123) may be exposed by extending from one side of the non-coated portion (126) and the non-coated portion (127). Even if deformation of the electrode assembly (101) occurs due to the exposed insulating layer (123), contact between the electrodes is prevented, thereby preventing a short circuit. The electrode assembly (101) can be formed by winding a first electrode (110), a separator (130) placed on the first electrode (110), and a second electrode (120) placed on the separator (130) around a core.

[0136] Referring to the second example (300b) of FIG. 3, the electrode assembly (102) may include a first electrode (110) including a first substrate layer (112) and a first composite layer (114) coated on both sides of the first substrate layer (112), a second substrate layer (121) and a third substrate layer (122), an insulating layer (123) disposed between the second substrate layer (121) and the third substrate layer (122), a second electrode (120) including a second composite layer (124) coated on the second substrate layer (121) and a third composite layer (125) coated on the third substrate layer (122), and a separator (130) disposed between the first electrode (110) and the second electrode (120). The first electrode (110) of the electrode assembly (102) can serve as a cathode, and the second electrode (120) can serve as an anode.

[0137] At least a portion of the first substrate layer (112) of the first electrode (110) may include a non-coated portion (116) on which the first composite layer (114) is not coated. The insulating layer (123) of the second electrode (120) may be exposed by extending from one side of the second substrate layer (121) and the third substrate layer (122). Even if deformation of the electrode assembly (102) occurs due to the exposed insulating layer (123), contact between the electrodes is prevented, thereby preventing a short circuit. The electrode assembly (102) may be formed by winding the first electrode (110), the separator (130) disposed on the first electrode (110), and the second electrode (120) disposed on the separator (130) around the core portion.

[0138] Referring to the third example (400a) of FIG. 4, the electrode assembly (103) may include a first electrode (110) including a first substrate layer (112) and a first composite layer (114) coated on both sides of the first substrate layer (112), a second substrate layer (121) and a third substrate layer (122), an insulating layer (123) disposed between the second substrate layer (121) and the third substrate layer (122), a second electrode (120) including a second composite layer (124) coated on the second substrate layer (121) and a third composite layer (125) coated on the third substrate layer (122), and a separator (130) disposed between the first electrode (110) and the second electrode (120). The first electrode (110) of the electrode assembly (103) can serve as a cathode, and the second electrode (120) can serve as an anode.

[0139] At least a portion of the second substrate layer (121) of the second electrode (120) may include a non-coated portion (126) on which the second composite layer (124) is not coated, and at least a portion of the third substrate layer (122) of the second electrode (120) may include a non-coated portion (127) on which the third composite layer (125) is not coated. Here, the insulating layer (123) may be exposed by extending from one side of the non-coated portion (126) and the non-coated portion (127). Even if deformation of the electrode assembly (103) occurs due to the exposed insulating layer (123), contact between the electrodes is prevented, thereby preventing a short circuit. The electrode assembly (103) may be formed by winding a first electrode (110), a separator (130) disposed on the first electrode (110), and a second electrode (120) disposed on the separator (130) around a core portion.

[0140] Referring to the fourth example (400b) of FIG. 4, the electrode assembly (104) may include a first electrode (110) including a first substrate layer (112) and a first composite layer (114) coated on both sides of the first substrate layer (112), a second substrate layer (121) and a third substrate layer (122), an insulating layer (123) disposed between the second substrate layer (121) and the third substrate layer (122), a second electrode (120) including a second composite layer (124) coated on the second substrate layer (121) and a third composite layer (125) coated on the third substrate layer (122), and a separator (130) disposed between the first electrode (110) and the second electrode (120). The first electrode (110) of the electrode assembly (104) can serve as a cathode, and the second electrode (120) can serve as an anode.

[0141] The insulating layer (123) of the second electrode (120) may be exposed by extending from one side of the second substrate layer (121) and the third substrate layer (122). Even if deformation of the electrode assembly (104) occurs due to the exposed insulating layer (123), contact between the electrodes is prevented, thereby preventing a short circuit. The electrode assembly (104) may be formed by winding a first electrode (110), a separator (130) disposed on the first electrode (110), and a second electrode (120) disposed on the separator (130) around a core portion.

[0142] The electrode assemblies (101, 102, 103, 104) disclosed in FIGS. 3 and 4 disclosed above may be various modified examples of the electrode assembly (100) disclosed in FIG. 1.

[0143] Fig. 5 is a drawing showing a first electrode (110) and a second electrode (120) according to one embodiment of the present invention. Among the configurations shown in Fig. 5, configurations described or duplicated in Figs. 1 to 4 are omitted.

[0144] Referring to the first example (500a) of FIG. 5, the first electrode (110) viewed in the first direction (D3) may include a first substrate layer (112) and a first composite layer (114) coated on both sides of the first substrate layer (112). In one embodiment, the first electrode (110) may be wound around the core with the first direction (D3) as the axial direction of the core. Here, the first substrate layer (112) includes a first upper uncoated portion (510) that is exposed to the outside of the first composite layer (114) in the axial direction of the core (i.e., the first direction (D3)), and the first upper uncoated portion (510) may include a plurality of first segmented portions (512) formed by notching at least a portion of the first upper uncoated portion (510). A first electrode (110) having such a structure may be defined as a so-called tab-less structure.

[0145] Referring to the second example (500b) of FIG. 5, the second electrode (120) viewed in the first direction (D3) may include a second substrate layer (121) and a third substrate layer (122), an insulating layer (123) disposed between the second substrate layer (121) and the third substrate layer (122), a second composite layer (124) coated on the second substrate layer (121), and a third composite layer (125) coated on the third substrate layer (122). In one embodiment, the second electrode (120) may be wound around the core with the first direction (D3) as the axial direction of the core. Here, the second base layer (121) includes a second upper plain portion (520) that is exposed to the outside of the second composite layer (124) in the axial direction of the core (i.e., the first direction (D3)), the third base layer (122) includes a third upper plain portion (530) that is exposed to the outside of the third composite layer (125) in the axial direction of the core (i.e., the first direction (D3)), and the second upper plain portion (520) and the third upper plain portion (530) may include a plurality of second segmented portions (540) that are formed by at least a portion being notched while being combined. A second electrode (120) having such a structure may be defined as a so-called tab-less structure.

[0146] In one embodiment, the area of ​​the insulating layer (123) of the second electrode (120) may be larger than the areas of each of the second substrate layer (121) and the third substrate layer (122). That is, the area of ​​the insulating layer (123) may be larger than the area of ​​the second substrate layer (121) and larger than the area of ​​the third substrate layer (122). Specifically, the length of the insulating layer (123) in the MD (machine direction) direction (D1) of the second electrode (120) may be set to be larger than the lengths of each of the second substrate layer (121) and the third substrate layer (122). In addition, the height of the insulating layer (123) in the TD (traverse direction) direction (D3) may be formed to be equal to the heights of each of the second substrate layer (121) and the third substrate layer (122), and smaller than the heights of the plurality of second segments (540). In this configuration, the insulating layer (123) can completely insulate the second substrate layer (121) and the third substrate layer (122) while extending and being exposed from one side of the second substrate layer (121) and the third substrate layer (122). Accordingly, even if deformation of the electrode assembly occurs, short circuits due to contact between electrodes can be effectively prevented.

[0147] In one embodiment, the area of ​​the insulating layer (123) of the second electrode (120) may be smaller than the areas of the second substrate layer (121) and the third substrate layer (122). Specifically, although not shown in FIG. 5, the length of the insulating layer (123) in the MD (machine direction) direction (D1) of the second electrode (120) may be set to be larger than the lengths of each of the second substrate layer (121) and the third substrate layer (122). On the other hand, the height of the insulating layer (123) in the TD (traverse direction) direction (D3) may be set to be smaller than the heights of each of the second substrate layer (121) and the third substrate layer (122). In such a configuration, the second electrode (120) may include a gap portion corresponding to an area where the insulating layer (123) does not exist between one edge of the second substrate layer (121) and one edge of the third substrate layer (122). In this way, by configuring the area of ​​the insulating layer (123) to be smaller than the areas of the second substrate layer (121) and the third substrate layer (122), the cost in the manufacturing process can be reduced.

[0148] FIG. 6 is a drawing showing a secondary battery (600) according to one embodiment of the present invention. Referring to FIG. 6, the secondary battery (600) according to one embodiment of the present disclosure includes an electrode assembly (610) that performs charging and discharging, a case (620) housing the electrode assembly (610), a first current collector plate (630) connected to the electrode assembly (610), a second current collector plate (650), an electrode terminal (641), a vent cap plate (642), and a gasket (660). In FIG. 6, the vent cap plate (642) is illustrated as being disposed on the upper portion of the secondary battery (600), and the electrode terminal (641) is illustrated as being disposed on the lower portion of the secondary battery (600), but is not limited thereto. Depending on the usage environment or requirements of the secondary battery (600), the vent cap plate (642) and the electrode terminal (641) may be changed to be positioned at the bottom and top of the secondary battery (600), respectively.

[0149] The electrode assembly (610) is formed by winding the first electrode (611a, 611b), the separator (613), and the second electrode (612a, 612b) into a cylindrical jelly roll state with an empty core. The first electrode (611a, 611b) and the second electrode (612a, 612b) may include a coated portion (611a, 612a) in which an active material is applied to both sides of a substrate each formed of a thin metal plate, and a non-coated portion (611b, 612b) in which the substrate is exposed because the active material is not applied.

[0150] Here, the electrode assembly (610) may have the same or similar configuration as the electrode assembly described with reference to other drawings.

[0151] In one embodiment, the first electrode (611a, 611b) may have the same or similar configuration as the first electrode (110) disclosed in FIGS. 1 to 5. For example, the coating portion (611a) of the first electrode (611a, 611b) may correspond to the first substrate layer (112) and the first composite layer (114) of the first electrode (110) disclosed in FIGS. 1 to 5, and the uncoated portion (611b) of the first electrode (611a, 611b) may correspond to the first upper uncoated portion (510) and the first segment portion (512) of the first electrode (110) disclosed in FIG. 5.

[0152] In one embodiment, the second electrode (612a, 612b) may have the same or similar configuration as the second electrode (120) disclosed in FIGS. 1 to 5. For example, the coating portion (612a) of the second electrode (612a, 612b) may correspond to the second substrate layer (121), the third substrate layer (122), the insulating layer (123), the second composite layer (124), and the third composite layer (125) of the second electrode (120) disclosed in FIGS. 1 to 5, and the uncoated portion (612b) of the second electrode (612a, 612b) may correspond to the second upper uncoated portion (520), the third upper uncoated portion (530), and the second segment portion (540) of the second electrode (120) disclosed in FIG. 5.

[0153] The first electrode (611a, 611b) may be an electrode corresponding to a positive or negative electrode in the secondary battery (600). The second electrode (612a, 612b) may be an electrode corresponding to a pole opposite to the first electrode (611a, 611b). For example, if the first electrode (611a, 611b) is a positive electrode, the second electrode (612a, 612b) may be a negative electrode. Conversely, if the first electrode (611a, 611b) is a negative electrode, the second electrode (612a, 612b) may be a positive electrode.

[0154] The uncoated portion (611b) of the first electrode and the uncoated portion (612b) of the second electrode are respectively provided at opposite ends of the winding axis of the electrode assembly (610), but electrode terminals (641) and a case (620) having different polarities in the same direction may be provided together. A vent cap plate (642) may be positioned on the opposite side of the electrode terminal (641).

[0155] The electrode assembly (610) including the first electrode (611a, 611b) and the second electrode (612a, 612b) disclosed above may have the same or similar configuration as the electrode assembly (100, 101, 102, 103, 104) described with reference to FIGS. 1 to 5.

[0156] The case (620) is formed in a cylindrical shape to house the electrode assembly (610), and the electrode terminal (641) and the vent cap plate (642) are provided at opposite axial ends of the case (620) so as to face each other. In one embodiment, the diameter of the case (620) may be 40 mm to 50 mm.

[0157] The electrode terminal (641) is connected to the first electrode (611a, 611b) through the first collector plate (630) via a rivet (643), and the case (620) is connected to the second electrode (612a, 612b) through the second collector plate (650). At this time, the vent cap plate (642) may be electrically separated from the second collector plate (650) and the case (620) and may not have polarity.

[0158] An electrode terminal (641) connected to a first electrode (611a, 611b) of an electrode assembly (610) inserted into a case (620) from the outside may be installed on one side of the case. The case (620) may have a partially open through hole (621) on one side.

[0159] In one embodiment, the electrode terminal (641) may be installed in a rivet structure in the through hole (621) of the case (620). For this purpose, the electrode terminal (641) may be connected to a rivet (643). One end of the rivet (643) may be welded to the first collector plate (630) and may be arranged to penetrate the through hole (621). The electrode terminal (641) may be connected to the rivet (643) and arranged on the outside of the case (620). The electrode terminal (641) may be formed to protrude beyond the outer surface of the case (620) around the through hole (621) and may be used as a positive electrode terminal. At this time, the first collector plate (630) may be a positive electrode collector plate. At this time, the first collector plate (630) can be electrically connected to the non-conductive portion (611b) of the first electrode (611a, 611b) through the rivet (643) and can be electrically and mechanically connected to the electrode terminal (641). The first collector plate (630) can be electrically connected to the electrode terminal (641) in a structure that reduces resistance by contacting most of the non-conductive portion (611b) of the first electrode (611a, 611b). The rivet (643) included in the electrode terminal (641) can be installed in an electrically insulated state from the case (620) while forming a sealing structure with respect to the electrolyte by arranging an insulator (623) in the through hole (621).

[0160] Here, the insulator (623) may be made of a polymer including ethylene propylene rubber (EPDM), polypropylene (PP), polyimide (PI), polyethylene terephthalate (PET), polycarbonate (PC), or a combination thereof.

[0161] As another example, the insulator (623) may be made of a ceramic material including epoxy resin, alumina (Al2O3), zirconia (ZrO2), aramid fiber, Nomex, or a combination thereof. However, the material of the insulator (923) is not limited to the materials listed above, and may include various materials with excellent plasticity and insulation properties depending on the selection.

[0162] In one embodiment, the first collector plate (630) may include a metal plate (631) including at least one bridge (632). For example, the first collector plate (630) may be formed of a conductive metal, specifically, a conductive metal such as nickel, aluminum, copper, silver, zinc, tin, stainless steel (e.g., SUS), nickel-plated steel, or a combination (alloy) thereof. In addition, the metal plate (631) and the bridge (632) constituting the first collector plate (630) may be made of the same material to form an integral body.

[0163] Here, the bridge (632) of the first collector plate (630) may be configured to be ruptured when a current exceeding a set value flows. For example, the bridge (632) normally operates as a part of a circuit through which current flows, but when an excessive amount of current flows, it may function as a fuse that melts due to the generated heat and blocks the circuit.

[0164] An insulating sheet (645) may be attached to one side of the first collector plate (630). The insulating sheet (645) may be placed between the first collector plate (630) and the case (620) or between the non-conductive portion (611b) of the first electrode (611a, 611b) and the case (620), and may perform a function of electrically insulating each component. In one embodiment, the central portion of the insulating sheet (645) may include a perforation (646) corresponding to the shape of the rivet (643) so that the rivet (643) may come into contact with the first collector plate (630). In addition, the insulating sheet (645) may include a side wall (647) so as to surround a portion of the electrode assembly (610).

[0165] Additionally, the case (620) may include a fully open opening (622) to allow the electrode assembly (610) to be inserted into the other side. The vent cap plate (642) may seal the opening (622) after the electrode assembly (610) is inserted into the case (620) and may be electrically isolated from the case (620).

[0166] At this time, the second collector plate (650) may be electrically connected to the non-conductive portion (612b) of the second electrode (612a, 612b) and may be electrically connected to the case (620). The second collector plate (650) may be connected to the case (620) in a structure that reduces resistance by contacting most of the non-conductive portion (612b) of the second electrode (612a, 612b).

[0167] The second collector plate (650) may include a bottom portion (651) welded to the non-coated portion (612b) of the second electrode (612a, 612b) and wing portions (652) formed adjacent to the bottom portion (651) and welded to the beading portion (629). The second collector plate (650) is formed by cutting and bending a circular plate, and may include a plurality of bottom portions (651) and wing portions (652), which may be arranged alternately along the circumferential direction. In one embodiment, the wing portions (652) may be repeatedly formed by bending the axial direction (upward) and radial direction (outer) of the electrode assembly (610).

[0168] In one embodiment, when the non-coated portion (612b) of the second electrode (612a, 612b) and the bottom portion (651) of the second collector plate (650) are welded, the bottom portion (651) can form a welding line in the diameter direction of the second collector plate (650). Accordingly, the bottom portion (651) can be evenly connected along the circumferential direction in the region of the non-coated portion (612b) of the second electrode (612a, 612b), and the wing portion (652) can be evenly connected along the circumferential direction in the region of the beaded portion (629). This can enable a uniform current flow along the circumferential direction in the entire region of the beaded portion (629) of the case (620) in the non-coated portion (612b) of the second electrode (612a, 612b).

[0169] In addition, since the second collector plate (650) has a hole (653) in the center, it can absorb and alleviate deformation caused by welding of the non-conductive portion (612b) of the bottom portion (651) and the second electrode (612a, 612b), as well as vibration and shock that may be transmitted between the wing portion (652) and the bottom portion (651). The hole (653) can have a size that can absorb vibration and shock without increasing current resistance between the wing portion (652) and the bottom portion (651).

[0170] The vent cap plate (642) may be electrically isolated from the second collector plate (650) and installed in the opening (622) of the case (620) by a crimping process. Alternatively, the vent cap plate (642) may be installed in the opening (622) of the case (620) by a welding process. Due to the connection of the second collector plate (650), the case (620) may be used as a negative terminal. In this case, the second collector plate (650) may be a negative collector plate.

[0171] The vent cap plate (642) may form a notch (644) on its inner surface. The notch (644) may be cut open to release internal pressure of the secondary battery to the outside when an abnormal event occurs in the secondary battery, thereby preventing a secondary explosion. Specifically, the notch (644) may be easily cut open by receiving concentrated internal pressure in the event of an abnormal event. The notch (644) may be formed over the entire circumferential area of ​​the vent plate (642), or may be formed in multiple pieces spaced apart at set intervals.

[0172] The gasket (660) can be interposed between the second collector plate (650) and the vent cap plate (642) and between the second collector plate (630) and the case (620) to provide a sealing effect through a beading portion (629) or a clamping process. In addition, the gasket (660) can form a gas-tight structure with respect to the electrolyte between the second collector plate (630) and the opening (622) of the case (620).

[0173] For example, the gasket (660) may include a polymer material or ceramic such as polyvinyl chloride (PVC), polytetrafluoroethylene (PTFE or Teflon), polyethylene (PE), epoxy resin, silicone, polyvinylidene fluoride (PVDF), polypropylene (PP), polyacrylonitrile (PAN), or polyethylene oxide (PEO), but is not limited thereto, and may correspond to any one of the appropriate compounds used as an insulating material in the art.

[0174] The finishing tape (690) may be attached so as to wrap the outer surface of the jelly roll of the electrode assembly (610) at least once. In addition, the electrode assembly (610) may be inserted into the case (620) with the finishing tape (690) attached, and the finishing tape (690) may be positioned between the electrode assembly (610) and the case (620). Therefore, in the secondary battery after assembly, the electrode assembly (610) does not move in the up-and-down or front-and-back direction inside the case (620), thereby preventing separation of the terminal or damage to the element, and even in a state where the electrode assembly (610) expands due to charging and discharging, cracks in the case (620) or the electrode assembly (610) due to excessive expansion of the electrode assembly (610) may be suppressed.

[0175] The secondary battery (600) may be a lithium secondary battery, a sodium secondary battery, etc. However, the scope of the present invention is not limited thereto, and the secondary battery (600) includes all batteries that can repeatedly provide electricity by charging and discharging.

[0176] A secondary battery according to one embodiment of the present invention can be applied to automobiles, mobile phones, and / or various types of electrical devices, but the present invention is not limited thereto.

[0177] FIG. 7 is a schematic drawing of an electrode assembly (3100) according to one embodiment of the present disclosure.

[0178] Referring to FIG. 7, an electrode assembly (3100) according to one embodiment of the present invention may be formed by winding a second electrode (3110), a separator (3130), and a first electrode (3120). In addition, the second electrode (3110), the first electrode (3120), and the separator (3130) may be impregnated with an electrolyte (not shown).

[0179] Specifically, the electrode assembly (3100) can be formed into a jelly roll state by sequentially winding the second electrode (3110), the separator (3130), and the first electrode (3120). A cavity can be formed inside the jelly roll (the core portion) where the second electrode (3110), the separator (3130), and the first electrode (3120) do not exist.

[0180] The second electrode (3110) may be an electrode corresponding to the positive or negative pole in the electrode assembly (3100). The first electrode (3120) may be an electrode corresponding to the opposite pole to the second electrode (3110). For example, if the second electrode (3110) is the positive pole, the first electrode (3120) may be the negative pole. Conversely, if the second electrode (3110) is the negative pole, the first electrode (3120) may be the positive pole.

[0181] The second electrode (3110) may include a first multilayer substrate (3140) in which a second substrate layer (3141), an insulating layer (3144), and a third substrate layer (3142) are laminated.

[0182] In one embodiment, when the second electrode (3110) is an anode, the second substrate layer (3141) or the third substrate layer (3142) may be formed of a metal foil such as aluminum or an aluminum alloy. In another embodiment, when the second electrode (3110) is a cathode, the second substrate layer (3141) or the third substrate layer (3142) may be formed of a metal foil such as copper, a copper alloy, nickel, or a nickel alloy. The materials of the second substrate layer (3141) and the third substrate layer (3142) are not limited to the materials listed above and may correspond to any one of the conductive metal materials used in the art. In addition, in one embodiment, the second substrate layer (3141) and the third substrate layer (3142) may be composed of different materials.

[0183] According to one embodiment of the present disclosure, the thickness of the second substrate layer (3141) or the third substrate layer (3142) may be 1 mm to 2 mm.

[0184] The insulating layer (3144) may be made of a polymer including, but not limited to, polyethylene terephthalate (PET), polyimide (PI), polyethylene (PE), polypropylene (PP), polycarbonate (PC), polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), ethylene propylene rubber (EPDM), or a combination thereof, and may correspond to any one of suitable compounds used as an insulating material in the art.

[0185] According to one embodiment of the present disclosure, the thickness of the insulating layer (3144) may be 4 mm to 8 mm.

[0186] According to one embodiment, the width of the insulating layer (3144) in the exposed section (3112) of the insulating layer (3144) may be greater than or equal to the width of the second substrate layer (3141) and the width of the third substrate layer (3142). Specifically, the insulating layer (3144) may include a first exposed portion (3146) exposed in one width direction of the second substrate layer (3141) and the third substrate layer (3142) in the exposed section (3112).

[0187] According to some embodiments of the present disclosure, even if expansion of the second electrode (3110) occurs due to charging and discharging of the electrode assembly (3100), the first multilayer substrate (3140) can prevent the occurrence of a short circuit by preventing contact between the substrate tab (3122) of the first electrode (3120) and the second electrode (3110) through the first exposed portion (3146) where the insulating layer (3144) is exposed in the exposed section (3112).

[0188] Here, the exposure section (3112) may be located at the core-side end of the electrode assembly (3100). The location of the exposure section (3112) is described later in FIG. 14.

[0189] According to some embodiments of the present disclosure, an electrode assembly (3100) including a first multilayer substrate (3140) has improved energy density per weight and can store the same energy as a substrate made of a single material while having an insulating layer (3144) interposed between the second substrate layer (3141) and the third substrate layer (3142), thereby improving material cost.

[0190] FIG. 8 is a plan view showing a cross-section of a portion of an electrode assembly according to one embodiment of the present disclosure.

[0191] Referring to FIG. 8, the second electrode (3210) can be formed by coating a second composite layer (3214) on a first multilayer substrate (3240). Here, the first multilayer substrate (3240) can be formed by laminating a second substrate layer (3241), an insulating layer (3244), and a third substrate layer (3242). The second composite layer (3214) can be formed by applying an active material and a binder to one side of the second substrate layer (3241) and the third substrate layer (3242), which are each formed of a thin metal plate.

[0192] Also, although not shown, the second electrode (3210) may include a second uncoated region (not shown), which is an area where a portion of the second substrate layer (3241) or the third substrate layer (3242) of the first multilayer substrate (3240) is exposed because the second composite layer (3214) is not coated. The second uncoated region will be described later in FIG. 10.

[0193] Likewise, the first electrode (3220) may also include a region where a first composite layer (3224) is coated on both sides of a second substrate, each formed of a thin metal plate, and a first uncoated portion (3226), which is a region where the first composite layer (3224) is not coated and the second substrate is exposed. A substrate tab (3222) may be formed at one end of the first uncoated portion (3226). According to one embodiment, the substrate tab (3222) may be bent in the centripetal direction of the electrode assembly. This will be described later with reference to FIG. 15.

[0194] According to one embodiment, the insulating layer (3244) may include a first exposed portion (3246) exposed in one width direction of the second substrate layer (3241) and the third substrate layer (3242) in the exposed section. Here, the height (3h2) of the first exposed portion (3246) may be 1.5 mm to 2.5 mm.

[0195] A separator (3230) is interposed between the second electrode (3210) and the first electrode (3220), and the height of the separator (3230) may be greater than or equal to the height of the second electrode (3210) or the height of the first electrode (3220) in order to insulate the second electrode (3210) and the first electrode (3220). Specifically, the height difference (h1) between the second composite layer (3214) and the separator (3230) may be greater than or equal to the height (h2) of the first exposed portion (3246).

[0196] In addition, the description of the configuration is the same as the description described above with reference to Fig. 7.

[0197] FIG. 9 is a plan view showing a cross-section of an electrode assembly before and after expansion according to one embodiment of the present disclosure.

[0198] Referring to FIG. 9, during the charging and discharging process of the electrode assembly, the volume of the second electrode (3310) of the electrode assembly may expand or contract due to changes in chemical energy while ions move inside the battery and transfer electrical energy.

[0199] Specifically, when comparing the appearance of the electrode assembly (3301) before expansion and the electrode assembly (3302) after expansion, in the electrode assembly (3301) before expansion, the length of the first multilayer substrate (3340) constituting the second electrode (3310) is short, so that the second substrate layer (3341), the insulating layer (3344), and the third substrate layer (3342) may not all touch the substrate tab of the first electrode (3320). In particular, it is preferable that the first exposed portion (3346) does not touch the substrate tab of the first electrode (3320).

[0200] On the other hand, in the electrode assembly (3302) after expansion, the lengths of the second substrate layer (3341), the insulating layer (3344), and the third substrate layer (3342) constituting the multilayer substrate (3340) all increase so that they can be arranged around the substrate tab of the first electrode (3320). However, the first exposed portion (3347) where the insulating layer (3344) is exposed may first contact the substrate tab of the first electrode (3320) to prevent further length expansion of the multilayer substrate (3340), or may be interposed between the second substrate layer (3341) and the first electrode (3320) or between the third substrate layer (3342) and the first electrode (3320) to prevent the occurrence of a short circuit.

[0201] FIG. 10 is a drawing illustrating one end of an electrode assembly according to one embodiment of the present disclosure.

[0202] Referring to FIG. 10, the first multilayer substrate (3440) may be formed by sequentially stacking a second substrate layer (3441), an insulating layer (3444), and a third substrate layer (3442). Here, the insulating layer (3444) may include a first exposed portion (3446) exposed in one width direction of the second substrate layer (3441) and the third substrate layer (3442) in the exposed section (3412). In one embodiment, the height (h2) of the first exposed portion may be 2% to 5% of the width length (h3) of the first multilayer substrate.

[0203] The exposed section (3412) may be located at one end of the electrode assembly. Specifically, the exposed section (3412) may refer to a section having a specific length located at the end of the core portion of the electrode assembly. In one embodiment, the length of the exposed section (3412) may be 1% to 1.5% of the length of the first multilayer substrate (3440).

[0204] Additionally, according to one embodiment, the second electrode may include a second non-coated portion (3416) on which the second composite layer (3414) is not applied on the first multilayer substrate (3440). The second composite layer (3414) may be formed by applying an active material and a binder to one side of the second substrate layer (3441) and the third substrate layer (3442), which are each formed of a thin metal plate. Here, the second non-coated portion (3416) may be positioned in an opposite direction to the first exposed portion (3446).

[0205] FIG. 11 is a drawing illustrating one end of an electrode assembly according to one embodiment of the present disclosure.

[0206] Referring to Fig. 11, the first multilayer substrate (3540) may be formed by sequentially stacking a second substrate layer (3541), an insulating layer (3544), and a third substrate layer (3542). Here, the insulating layer (3544) may include a first exposed portion (3546) exposed in one width direction of the second substrate layer (3541) and the third substrate layer (3542) in the exposed section (3512).

[0207] According to one embodiment, the length of the insulating layer (3544) may be greater than or equal to the length of the second substrate layer (3541) or the third substrate layer (3542). Through this, the insulating layer (3544) may form a first exposed portion (3546) that is exposed not only in one width direction (up-down direction in FIG. 11) of the second substrate layer (3541) and the third substrate layer (3542), but also in one length direction (left-right direction in FIG. 11) of the second substrate layer (3541) and the third substrate layer (3542).

[0208] Specifically, the first exposed portion (3546) is exposed to a length greater than the exposed section (3512) located at one end of the electrode assembly, so that when the electrode assembly is wound, the first exposed portion (3546) can be located at the core of the electrode assembly.

[0209] FIG. 12 is a drawing illustrating a portion of a second electrode (3601) according to one embodiment of the present disclosure. FIG. 13 is a drawing illustrating a cross-section (3602) of a second electrode according to one embodiment of the present disclosure.

[0210] Referring to FIGS. 12 and 13, a second substrate tab (3618) may be formed on at least a portion of the second non-conductive portion (3616) of the second electrode (3601). Through the second substrate tab (3618), the second electrode (3601) may be electrically connected to other components of the secondary battery (e.g., a current collector).

[0211] The second substrate tab (3618) may be attached by welding a metal substrate onto the second non-coated portion (3616) after the second composite layer (3614) is applied. Specifically, some of the metal substrates may be welded to the upper portion of the second substrate layer (3641) and the upper portion of the third substrate layer (3642) in the second non-coated portion (3616), and the remaining portions of the metal substrates may be welded to each other to form a shape that surrounds the second non-coated portion (3616).

[0212] Here, the metal substrate may be made of the same material as the material constituting the second substrate layer (3641) or the third substrate layer (3642) of the first multilayer substrate (3640).

[0213] The second non-coated portion (3616) of the second electrode (3601) can be welded to the second substrate tab (3618) using any one of ultrasonic welding, laser welding, resistance welding, TIG welding (Tungsten Inert Gas Welding), or a combination thereof. The welding method is not limited to the types of welding listed above, and various methods generally used for welding two materials can be used according to the choice of a person skilled in the art.

[0214] Here, the second non-coated portion (3616) may be positioned in the opposite direction to the first exposed portion (3646) located in the exposed section (3612) of the insulating layer (3644). Accordingly, the second substrate tab (3618) formed on the second non-coated portion (3616) may also be positioned in the opposite direction to the first exposed portion (3646).

[0215] The length of the second substrate tab (3618) may correspond to the length of the exposed section (3612) of the insulating layer (3644). For example, the length of the second substrate tab (3618) may correspond to the length of the second non-woven portion (3616) minus the length of the exposed section (3612) of the insulating layer (3644). When the length of the exposed section (3612) of the insulating layer (3644) is 10% of the length of the second non-woven portion (3616), the length of the second substrate tab (3618) may be 90% of the length of the second non-woven portion (3616).

[0216] In addition, the description of the configuration is the same as the description described above with reference to Fig. 7.

[0217] FIG. 14 is a schematic diagram illustrating an appearance of a pre-coiling electrode assembly according to one embodiment of the present disclosure.

[0218] Referring to FIG. 14, an electrode assembly according to one embodiment of the present disclosure may include a second electrode (3810) and a first electrode (3820).

[0219] The second electrode (3810) may have the same or similar configuration as the second electrodes (3110, 3210, 3310, 3601, 3602) described with reference to FIGS. 7 to 13. In one embodiment, the second electrode (3810) may include a second uncoated portion (3816), which is an area where the second composite layer (3814) is not coated, and a second substrate tab (3818) may be formed on at least a portion of the second uncoated portion (3816).

[0220] The first electrode (3820) may include a first uncoated portion (3826), which is an area where the first composite layer (3824) is not applied, and a first substrate tab (3828) may be formed on at least a portion of the first uncoated portion (3826). The first substrate tab (3828) may be formed in the same manner as the second substrate tab (3618) described with reference to FIGS. 12 and 13 . For example, the first substrate tab (3828) may be formed in a shape that surrounds the first uncoated portion (3826).

[0221] Although not shown, the second substrate tab (3818) and the first substrate tab (3828) may include a plurality of metal segments formed by notching. The second substrate tab (3818) and the first substrate tab (3828) including the plurality of metal segments may be bent toward the winding direction after winding the electrode assembly.

[0222] According to one embodiment of the present disclosure, the first uncoated portion (3826) may be positioned in an opposite direction to the second uncoated portion (3816). In FIG. 14, the first uncoated portion (3826) is illustrated as being positioned at the bottom of the electrode assembly, and the second uncoated portion (3816) is illustrated as being positioned at the top of the electrode assembly, but this is not limited thereto.

[0223] Here, the exposed section (3812) and the first exposed portion (3846) of the second electrode (3810) may be located at the end of the core side (C) of the electrode assembly. In contrast, the second exposed portion (3856) of the first electrode (3820) may be located at the end of the outer side (D) of the electrode assembly.

[0224] According to one embodiment, in the second electrode (3810), a portion of the second uncoated portion (3816) on the core side (C) may be absent from the core side configuration (e.g., a collector plate). In addition, a portion of the second uncoated portion (3816) on the outer side (D) may be absent from the case. Similarly, in the first electrode (3820), a portion of the first uncoated portion (3826) on the core side (C) and a portion of the first uncoated portion (3826) on the outer side (D) may be absent.

[0225] Although not shown in FIG. 14, according to one embodiment, the length of the second uncoated portion (3816) may become shorter as it moves from the center of the second electrode toward the core side (C) of the electrode assembly. Further, according to one embodiment, the length of the second uncoated portion (3816) may become shorter as it moves from the center of the second electrode toward the outer side (D) of the electrode assembly. Alternatively or additionally, in one embodiment, the length of the first uncoated portion (3826) may become shorter as it moves from the center of the first electrode toward the core side (C) of the electrode assembly. Further, the length of the first uncoated portion (3826) may become shorter as it moves from the center of the first electrode toward the outer side (D) of the electrode assembly.

[0226] Through this, the length of the second substrate tab (3818) or the first substrate tab (3828) that is absent can be minimized to secure a cavity located in the core of the electrode assembly. In addition, the length of the second substrate tab (3818) or the first substrate tab (3828) that is absent can be minimized to secure a safety clearance from the case on the outer side.

[0227] In addition, the description of the configuration is the same as the description described above with reference to Fig. 7.

[0228] FIG. 15 is a plan view illustrating a cross-section of an electrode assembly (3900) after winding according to one embodiment of the present disclosure.

[0229] Referring to FIG. 15, an electrode assembly (3900) according to one embodiment of the present disclosure may include a second electrode (3910), a first electrode (3920), and a separator (3930) interposed between the second electrode (3910) and the first electrode (3920).

[0230] In one embodiment, the second electrode (3910) may include a first multilayer substrate (3940). The first multilayer substrate (3940) may have the same or similar configuration as the first multilayer substrates (3140, 3240, 3340, 3440, 3540, 3640) described with reference to FIGS. 7 to 13. For example, the first multilayer substrate (3940) may be formed by sequentially stacking a second substrate layer (3941), an insulating layer (3944), and a third substrate layer (3942), and may include a first exposed portion (3946) in which a portion of the insulating layer (3944) is exposed.

[0231] In one embodiment, the first electrode (3920) may include a second multilayer substrate (3950) having a similar configuration to the first multilayer substrate (3940) included in the second electrode (3910). For example, the second multilayer substrate (3950) may be formed by sequentially stacking a third substrate layer (3951), an insulating layer (3954), and a fourth substrate layer (3952), and may include a second exposed portion (3956) in which a portion of the insulating layer (3954) is exposed.

[0232] In an electrode assembly (3900) according to one embodiment, the second electrode (3910) may include a plurality of second uncoated portions (3916) that are not coated with a second composite layer (3914). The plurality of second uncoated portions (3916) of the second electrode (3910) may all be disposed on one side of the electrode assembly (3900) in the same direction. In contrast, the plurality of first uncoated portions (3926) of the first electrode (3920) according to one embodiment of the present disclosure that are not coated with a first composite layer (3924) may be disposed in an opposite direction to the plurality of second uncoated portions (3916) of the second electrode (3910).

[0233] Specifically, the first multilayer substrate (3940) included in the second electrode (3910) and the second multilayer substrate (3950) included in the first electrode (3920) may be arranged in opposite directions. In FIG. 15, the first non-coated portion (3926) is illustrated as being arranged on the upper portion of the electrode assembly (3900) and the second non-coated portion (3916) is illustrated as being arranged on the lower portion of the electrode assembly (3900), but the present invention is not limited thereto.

[0234] According to one embodiment, the second substrate tab (3918) and the first substrate tab (3928) can be bent toward the winding direction of the electrode assembly (3900). Even when the volume of the electrode assembly (3900) according to the present invention expands during a charge / discharge process, the first exposed portion (3946) of the second electrode (3910) can first contact the first substrate tab (3928) of the first electrode (3920) to prevent a short circuit, and the second exposed portion (3956) of the first electrode (3920) can first contact the second substrate tab (3918) of the second electrode (3910) to prevent a short circuit.

[0235] Figure 16 is a flowchart showing an example of a method for manufacturing a secondary battery according to the present disclosure.

[0236] A method for manufacturing an electrode assembly according to one embodiment of the present invention (4100) may begin by stacking a second substrate layer, an insulating layer, and a third substrate layer to produce a first multilayer substrate (S4110). Here, the thickness of the second substrate layer or the third substrate layer may be 1 mm to 2 mm. The thickness of the insulating layer may be 4 mm to 8 mm. According to one embodiment, the length of the insulating layer may be greater than or equal to the length of the second substrate layer or the third substrate layer.

[0237] Additionally, the method for manufacturing an electrode assembly according to one embodiment (4100) may further include a step of manufacturing a second electrode by applying a second composite layer on a multilayer substrate.

[0238] Thereafter, the second electrode including the first multilayer substrate, the separator, and the first electrode can be wound (S4120). At this time, the width of the insulating layer in the exposed section of the insulating layer of the second electrode may be greater than or equal to the width of the second substrate layer or the width of the third substrate layer. Specifically, the insulating layer may include a first exposed portion exposed in one width direction of the second substrate layer and the third substrate layer in the exposed section. Here, the height of the first exposed portion may be 0.5 mm to 2 mm. In another embodiment, the height of the first exposed portion may be 2% to 5% of the width length of the first multilayer substrate. Here, the exposed section may be located at the end of the core side of the electrode assembly, and the length of the exposed section may be 1% to 1.5% of the length of the multilayer substrate.

[0239] Additionally, the second electrode may include a second uncoated portion to which the second composite layer is not applied, and the first electrode may include a first uncoated portion to which the first composite layer is not applied. Here, the second uncoated portion may be positioned in an opposite direction to the first exposed portion. Additionally, in one embodiment, the first uncoated portion may be positioned in an opposite direction to the second exposed portion.

[0240] A method for manufacturing an electrode assembly (4100) according to one embodiment may further include a step of forming a first substrate tab on at least a portion of a first non-coated portion before the step (S4120) of winding the second electrode, separator, and first electrode including a multilayer substrate. In one embodiment, the method for manufacturing an electrode assembly (4100) may further include a step of forming a second substrate tab on the second non-coated portion.

[0241] According to one embodiment of the present disclosure, the step of forming a substrate tab on the first non-woven portion may include the step of welding and attaching a metal substrate to the first non-woven portion and the step of notching the metal substrate.

[0242] A method (4100) for manufacturing an electrode assembly according to one embodiment may further include a step of bending a substrate tab. According to one embodiment, the second substrate tab or the first substrate tab may be bent toward the winding direction of the electrode assembly. Specifically, the second substrate tab or the first substrate tab may be formed by a compaction process toward the winding direction of the electrode assembly.

[0243] An electrode assembly comprising a multilayer substrate according to some embodiments of the present disclosure has a low possibility of ignition due to short circuits in penetration or collision of cells, and can advantageously secure welding conditions of a current collector due to increased overlapping of the substrate layers.

[0244] Fig. 17 is a flowchart (700) illustrating a method for manufacturing an electrode assembly (100) according to one embodiment of the present invention. Figs. 18 to 23 are drawings illustrating a method for manufacturing the electrode assembly (100) according to Fig. 17. Referring to Figs. 17 and 18, a step (S710) of mixing a slurry (820) containing an active material, a binder, and a conductive material in a mixing device (810) may be performed. Referring to Figs. 1 to 5, the slurry (820) may correspond to a material or substance included in any one of the first mixture layer (114), the second mixture layer (124), and the third mixture layer (125).

[0245] Referring to FIGS. 17 and 19, a step (S720) of coating a mixed slurry (820) on a plate (920) through a coating facility (910) may be performed. Referring to FIG. 1, the plate (920) may correspond to a first electrode (110) or a second electrode (120). In one embodiment, when manufacturing a first electrode (110), a plate (920) composed of a first substrate layer (112) may be prepared first. In one embodiment, when manufacturing a second electrode (120), a plate (920) may be prepared in which a second substrate layer (121) and a third substrate layer (122) are deposited (e.g., by vapor deposition, etc.) or plated (e.g., by electroless plating or electroplating, etc.) on an insulating layer (123).

[0246] In one embodiment, the horizontal / vertical length of the insulating layer (123) may be different from the horizontal / vertical lengths of the second substrate layer (121) and the third substrate layer (122). In this way, the insulating layer (123) in the second electrode (120) may be exposed by extending from one side of the second substrate layer (121) and the third substrate layer (122).

[0247] In one embodiment, the gap portion of the second electrode (120) may be formed by slitting the area of ​​the insulating layer (123) so that it is smaller than the areas of the second substrate layer (121) and the third substrate layer (122). In one embodiment, the coating equipment (910) may be a stripe coating machine. Although a stripe coating method is disclosed in FIG. 19, it is not limited thereto and various coating processes such as pattern coating may be performed.

[0248] Continuing with reference to FIGS. 1 to 5, a first composite layer (114) may be coated on a first substrate layer (112) of a first electrode (110). In addition, a second composite layer (124) may be coated on a second substrate layer (121) of a second electrode (120), and a third composite layer (125) may be coated on a third substrate layer (122). In one embodiment, the first electrode (110) may include a non-coated portion on the first substrate layer (112) where the first composite layer (114) is not coated. In one embodiment, the second electrode (120) may include a non-coated portion on the second substrate layer (121) and the third substrate layer (122) where the second composite layer (124) and the third composite layer (125) are not coated.

[0249] Referring to FIGS. 17 and 20, a step (S730) of pressing a coated plate (920) through a pressing device (1010) may be performed. In one embodiment, the pressing device (1010) may be a roll pressing machine. Although FIG. 20 discloses a pressing device (1010) corresponding to a roll pressing machine, the present invention is not limited thereto and the plate (920) may be pressed using various pressing devices.

[0250] Referring to FIGS. 17 and 21, a step (S740) of slitting a pressed electrode plate (920) through a slitting device (1110) may be performed. The slitting device (1010) may be a press device or a laser device. Referring to FIG. 5, the electrode plate (920) may correspond to the first electrode (110) or the second electrode (120).

[0251] Referring to FIGS. 17 and 22, a step (S750) of welding a general substrate (1210) to a plate (920) may be performed. Referring to FIG. 5, the plate (920) may correspond to a first electrode (110) or a second electrode (120). The step performed in FIG. 22 is performed only when manufacturing the second electrode (120), and may be omitted when manufacturing the first electrode (110). Referring to FIGS. 1 and 5, the plate (920) corresponds to the second electrode (120), and the welded non-coated portion (922) and the general substrate (1210) may correspond to a second upper non-coated portion (520) or a third upper non-coated portion (530). That is, by welding the general substrate (1210) to the plain portion (922), the second upper plain portion (520) of the second substrate layer (121) and the third upper plain portion (530) of the third substrate layer (122) can be formed. Here, the second upper plain portion (520) and the third upper plain portion (530) can include a plurality of second segmented portions (540) formed by at least a portion being notched in a combined state. Specifically, the welded plain portion (922) and the general substrate (1210) corresponding to the second upper plain portion (520) and the welded plain portion (922) and the general substrate (1210) corresponding to the third upper plain portion (530) can be joined to each other, and at least a portion of them can be notched to form a plurality of second segmented portions (540). In one embodiment, the welding can include laser welding.

[0252] Referring to FIGS. 17 and 23, a step (S760) of winding the electrode plate (920) manufactured through the manufacturing method disclosed in FIGS. 17 to 21 may be performed. A plurality of electrode plates (920) may be manufactured. Here, referring to FIG. 1, one electrode plate (920) may correspond to the first electrode (110), and another electrode plate (920) may correspond to the second electrode (120). Referring to FIG. 5, before winding the first electrode (110), a plurality of first segmented portions (512) may be formed by notching or cutting at least a portion of the first upper uncoated portion (510) of the first electrode (110). Referring to FIG. 5, before winding the second electrode (120), a plurality of second segments (540) can be formed by joining the second upper uncoated portion (520) and the third upper uncoated portion (530) of the second electrode (120) together and notching or cutting some of them.

[0253] Continuing with reference to FIG. 1, an electrode assembly (100) can be formed by winding a separator (130) between a first electrode (110) and a second electrode (120) around a core portion. Here, the detailed configuration of the first electrode (110) or the second electrode (120) can correspond to the detailed configuration of the first electrode (110) and the second electrode (120) disclosed in FIGS. 1 to 5, respectively. The electrode assembly (100) can have various modified examples such as electrode assemblies (101, 102, 103, 104) disclosed in FIGS. 3 and 4.

[0254] FIG. 24 and FIG. 25 are schematic diagrams showing examples of secondary batteries according to one embodiment of the present disclosure.

[0255] Referring to FIGS. 24 and 25, a secondary battery according to an embodiment of the present invention may include an electrode assembly (5110) formed by stacking and then winding a first electrode, a separator, and a second electrode, a current collector (5130) disposed on one surface of the electrode assembly (5110), an insulating tape (5120) disposed between the electrode assembly (5110) and the current collector (5130), and a case (5140) housing the electrode assembly (5110). Specifically, FIG. 24 is a drawing illustrating a process of forming an assembly of the electrode assembly (5110), the insulating tape (5120), and the current collector (5130).

[0256] The first electrode of the electrode assembly (5110) may be an electrode corresponding to a positive or negative electrode in a secondary battery. The second electrode may be an electrode corresponding to a polarity opposite to the first electrode. For example, if the first electrode is a positive electrode, the second electrode may be a negative electrode. Conversely, if the first electrode is a negative electrode, the second electrode may be a positive electrode.

[0257] In one embodiment, the electrode assembly (5110) is formed into a jelly roll state by sequentially winding a first electrode, a separator, and a second electrode. According to this configuration, the electrode assembly (5110) may include a through hole (5112) in the core portion.

[0258] The first electrode and the second electrode may include a coated portion, where an active material is applied to both sides of a substrate formed from a thin metal plate, and a non-coated portion, where the substrate is exposed because the active material is not applied. For example, the first electrode may form a positive electrode by coating a positive active material on an aluminum (Al) substrate, and the second electrode may form a negative electrode by coating a negative active material on a copper (Cu) substrate. The first electrode, the second electrode, and the separator may be impregnated with an electrolyte (not shown).

[0259] The outer surface of the electrode assembly (5110) may include a separator or a substrate layer constituting the electrode. Specifically, the outer surface of the electrode assembly (5110) may be configured in a form in which one end of a separator extended long from the separator wraps around the separator to prevent the active material constituting the first electrode or the second electrode from being exposed to the outside. In another example, the outer surface of the electrode assembly (5110) may be configured in a form in which one end of a substrate layer formed by extending a non-coated portion of a substrate layer on which the active material constituting the first electrode or the second electrode is not coated wraps around the substrate layer.

[0260] In one embodiment, the collector plate (5130) may be disposed on one surface of the electrode assembly (5110) and electrically connected to the first electrode or the second electrode. Specifically, the collector plate (5130) may be electrically connected to the electrode assembly (5110) through the non-conductive portion of the first electrode or the second electrode.

[0261] For example, the uncoated portion of the first electrode or the uncoated portion of the second electrode may be welded and joined to the current collector plate (5130). A portion of the current collector plate (5130) may protrude toward the electrode assembly (5110) to be welded to the uncoated portion of the first electrode or the uncoated portion of the second electrode.

[0262] Specifically, the current collector (5130) can be welded to the uncoated portion of the first electrode or the uncoated portion of the second electrode using any one of ultrasonic welding, laser welding, resistance welding, TIG welding (Tungsten Inert Gas Welding), or a combination thereof. The welding method is not limited to the types of welding listed above, and various methods generally used for welding two materials can be used according to the selection of a person skilled in the art.

[0263] In one embodiment, the insulating tape (5120) may include a body portion (5122) that insulates between the core portion of the electrode assembly (5110) and the collector plate (5130) and a leg portion (5124) extending from the body portion (5122).

[0264] Here, the body portion (5122) of the insulating tape (5120) may include a central hole (5126). Specifically, the body portion (5122) of the insulating tape (5120) may have a ring shape with an outer diameter of 5 mm to 20 mm centered on the central hole (5126).

[0265] In one embodiment, the central hole (5126) of the body portion (5122) may be positioned corresponding to the through hole (5112) of the electrode assembly (5110). For example, a welding rod inserted through the through hole (5112) of the electrode assembly (5110) may be exposed through the central hole (5126) without the intervening insulating tape (5120) and reach the current collector (5130). The welding rod inserted through the through hole (5112) may be used to weld the terminals of the electrode assembly (5110) and the secondary battery to each other.

[0266] According to one embodiment, the leg portion (5124) of the insulating tape (5120) may include two or more rods. Specifically, the leg portion (5124) of the insulating tape (5120) may be formed by radially arranging two or more rods centered on the body portion (5122). Here, two of the two or more rods may be formed to face each other.

[0267] Referring to FIG. 25, the leg portion (5124) of the insulating tape (5120) may be interposed between the outer surface (5114) of the electrode assembly (5110) and the case (5140). Specifically, the leg portion (5124) of the insulating tape (5120) may be bent along the outer surface (5114) of the electrode assembly (5110) so as to surround the electrode assembly (5110) during the process of inserting the assembly of the electrode assembly (5110), the insulating tape (5120), and the collector plate (5130) through the opening (5142) on one side of the case (5140).

[0268] In one embodiment, the leg portion (5124) and the body portion (5122) of the insulating tape (5120) may be formed as a single body with the same composition. Alternatively, the leg portion (5124) and the body portion (5122) of the insulating tape (5120) may be integrally joined. In this way, when the leg portion (5124) of the insulating tape (5120) is interposed between the outer surface (5114) of the electrode assembly (5110) and the case (5140), the entire insulating tape (5120) may be fixed to the same position by friction between the outer surface (5114) of the electrode assembly (5110) and the leg portion (5124) and friction between the case (5140) and the leg portion (5124). Here, the location where the insulating tape (5120) is fixed may be between the core (5112) of the electrode assembly (5110) and the current collector (5130). This will be described later in FIG. 26.

[0269] In one embodiment, the case (5140) forms the overall appearance of the secondary battery and may provide a space in which the electrode assembly (5110) is accommodated. For example, if the secondary battery is a cylindrical secondary battery, the case (5140) may have a cylindrical shape.

[0270] For the purpose of explaining the invention, the secondary battery is illustrated as a cylindrical secondary battery in FIGS. 24 to 30 below, but the scope of the present disclosure is not limited thereto. The secondary battery (5100) of the present invention is not limited to a cylindrical secondary battery, and includes secondary batteries of any shape, such as a square secondary battery, a pouch secondary battery, and a coin secondary battery.

[0271] In one embodiment, the insulating tape (5120) may be made of a polymer including ethylene propylene rubber (EPDM), polypropylene (PP), polyimide (PI), polyethylene terephthalate (PET), polycarbonate (PC), or a combination thereof.

[0272] As another example, the insulating tape (5120) may be made of a ceramic material including epoxy resin, alumina (Al2O3), zirconia (ZrO2), aramid fiber, Nomex, or a combination thereof. However, the material of the insulating tape (5120) is not limited to the materials listed above, and may include various materials with excellent plasticity and insulating properties depending on the selection.

[0273] According to some embodiments of the present disclosure, the stability and lifespan of a secondary battery can be increased by providing an insulating tape designed to be fixed at a location where a short circuit may occur, such as between a specific electrode of an electrode assembly and a current collector plate.

[0274] FIG. 26 is a cross-sectional view showing a portion of an electrode assembly according to one embodiment of the present disclosure.

[0275] Referring to FIG. 26, an electrode assembly (5302) according to one embodiment of the present invention can be formed by stacking a first electrode (5310), a separator (5313), and a second electrode (5320) and then winding them.

[0276] According to one embodiment, the first electrode (5310) may be formed by applying a first active material (5312) to both surfaces of a first substrate (5314), each formed of a thin metal plate. Similarly, the second electrode (5320) may be formed by applying a second active material (5322) to both surfaces of a second substrate (5324), each formed of a thin metal plate. The first electrode (5310) may be an electrode corresponding to a positive electrode or a negative electrode in a secondary battery. The second electrode (5320) may be an electrode corresponding to an opposite pole to the first electrode (5310). For example, when the first electrode (5310) is a positive electrode, the second electrode (5320) may be a negative electrode. Conversely, when the first electrode (5310) is a negative electrode, the second electrode (5320) may be a positive electrode.

[0277] As an example, the first electrode (5310) may form a positive electrode by coating a positive electrode active material on an aluminum (Al) substrate, and the second electrode (5320) may form a negative electrode by coating a negative electrode active material on a copper (Cu) substrate.

[0278] Specifically, the first electrode (5310) includes a first active material portion (5315) coated with a first active material (5312) along the winding direction of the electrode assembly (5302) and a first non-coated portion (5316) not coated with the first active material (5312), and the first non-coated portion (5316) may include a plurality of independently bendable segments (5318). According to one embodiment, the segments (5318) of the electrode assembly (5302) may be formed around the core portion (5304). However, one end of the first non-coated portion (5316) located in the core portion (5304) may be cut so as to be spaced apart from the current collector (5340).

[0279] A plurality of segments (5318) may be bent along the radial direction of the electrode assembly (5302) to form a substrate tab (5308). For example, as illustrated in FIG. 26, segments (5318) of the first non-conductive portion (5316) may be bent in the centripetal or radial direction of the electrode assembly (5302).

[0280] According to one embodiment of the present disclosure, the substrate tab (5308) may include a welding portion (5306) for welding with the current collector plate (5340). As described above with reference to FIG. 24, the current collector plate (5340) may be welded to the substrate tab (5308) of the first electrode (5310) at the welding portion (5306) using any one of ultrasonic welding, laser welding, resistance welding, TIG welding, or a combination thereof. The welding method is not limited to the types of welding listed above, and various methods generally used for welding two materials may be used according to the selection of a person skilled in the art.

[0281] Here, the body part (5350) of the insulating tape can be placed in an area of ​​the substrate tab (5308) excluding the welded portion (5306). For example, as illustrated in FIG. 26, the body part (5350) of the insulating tape can be placed between the current collector (5340) and the electrode assembly (5302) so as to correspond to the core part (5304) of the electrode assembly (5302) where the substrate tab (5308) does not exist.

[0282] In addition, the description of the configuration is the same as the description described above with reference to FIGS. 24 and 25.

[0283] According to some embodiments of the present disclosure, by placing an insulating tape between the electrode assembly and the current collector plate, a short circuit that may occur as the tip of the electrode assembly expands as the secondary battery is charged and discharged can be prevented.

[0284] Fig. 27 is a plan view illustrating one side of an electrode assembly according to one embodiment of the present disclosure. Specifically, Fig. 27 is a plan view illustrating the electrode assembly as viewed in a direction parallel to the winding axis of the electrode assembly.

[0285] Referring to Fig. 27, an electrode tab (5406) ​​may not be formed in the core portion (5404) centered on the through hole (5410) of the electrode assembly (5400), but may be formed around the core portion (5404). In addition, in order to prevent short circuits, an electrode tab (5406) ​​may not be formed around the outer peripheral surface (5408) of the electrode assembly (5400).

[0286] In addition, the description of the configuration is the same as the description described above with reference to Fig. 26.

[0287] Fig. 28 is a perspective view showing an insulating tape and a collector plate according to one embodiment of the present disclosure.

[0288] Referring to FIG. 28, a leg portion of an insulating tape according to one embodiment of the present disclosure may include two or more rods (5524). Here, at least two of the two or more rods (5524) may be formed to face each other.

[0289] According to one embodiment of the present disclosure, the width (B) of each of the two or more rods (5524) may be from 1 mm to 10 mm.

[0290] According to one embodiment of the present disclosure, the length (A) of each of two or more rods (5524) may be from 1 mm to 115 mm. Specifically, the length (A) of each rod (5524) may be set to be greater than the radius of the collector plate (5530), so that when an insulating tape is attached to the collector plate (5530), the rod (5524) may be exposed to the outside of the collector plate.

[0291] According to one embodiment of the present disclosure, one side of the body portion (5522) of the insulating tape, which faces the collector plate (5530), may be coated with an adhesive layer (5528). The insulating tape may be attached to the collector plate (5530) and fixed in position through the coated adhesive layer (5528) of the body portion (5522). The adhesive layer (5528) may correspond to the shape of the body portion (5522) of the insulating tape. Specifically, the adhesive layer (5528) may include a central hole (5526) at the center.

[0292] The adhesive layer (5528) may extend from the body portion (5522) of the insulating tape and may also be coated on some of the legs or rods (5524) of the insulating tape. For example, the adhesive layer (5528) may be coated on some surface of the legs or rods (5524) of the insulating tape that comes into contact with the collector plate (5530). Through this, the legs or rods (5524) of the insulating tape may be attached to the collector plate (5530) through the coated adhesive layer (5528), and the position of the insulating tape may be fixed.

[0293] In one embodiment, the adhesive layer (5528) may be coated on a portion of the surface of the legs or rods (5524) of the insulating tape that comes into contact with the electrode assembly. Specifically, a portion of the legs or rods (5524) of the insulating tape may come into contact with the outer surface of the electrode assembly (for example, the outer surface (5114) of FIGS. 24 and 25), and the adhesive layer (5528) may be coated on that surface. As a result, the legs or rods (5524) of the insulating tape may be attached to the electrode assembly through the coated adhesive layer (5528), and the position of the insulating tape may be fixed.

[0294] In one embodiment, the adhesive layer (5528) may include, but is not limited to, an acrylic adhesive such as polymethyl methacrylate (PMMA) or polybutyl methacrylate (PBMA), an epoxy adhesive, a polyurethane adhesive including thermoplastic polyurethane (TPU), a silicone adhesive, or a polyimide adhesive, and may correspond to any suitable compound used as an adhesive material in the art.

[0295] In addition, the description of the configuration is the same as the description described above with reference to FIGS. 24 to 27.

[0296] FIG. 29 is a plan view showing an insulating tape and a current collector plate according to one embodiment of the present disclosure.

[0297] Referring to FIG. 29, according to one embodiment of the present disclosure, the body portion (5622) of the insulating tape may be positioned to cover the notch (5632) of the collector plate (5630). The leg portion (5624) of the insulating tape may be spaced apart from the notch (5632) and have a length greater than the diameter of the collector plate (5630).

[0298] Here, the notch (5632) may be configured to be cut open to release internal pressure of the secondary battery to the outside when an abnormal event occurs in the secondary battery, thereby preventing a secondary explosion. Specifically, the notch (5632) may be configured to be easily cut open by intensively receiving internal pressure in the event of an abnormal event.

[0299] The location or shape of the notch (5632) may vary. In one embodiment, the notch (5632) may be formed over the entire area along the circumference centered on the central hole of the current collector plate (5630), or may be formed in multiple pieces spaced apart at set intervals.

[0300] According to some embodiments of the present disclosure, at least a portion of the insulating tape is positioned to cover a notch (5632) formed in the current collector (5630) to protect the electrode assembly from the external environment and prevent corrosion of the notch (5632), thereby preventing defects caused by corrosion in the secondary battery.

[0301] In addition, the description of the configuration is the same as the description described above with reference to Fig. 28.

[0302] FIG. 30 is a cross-sectional view showing an example of a secondary battery according to one embodiment of the present disclosure.

[0303] Referring to FIG. 30, a secondary battery according to an embodiment of the present disclosure includes an electrode assembly (5710) that performs charging and discharging, a case (5720) housing the electrode assembly (5710), a first collector plate (5730) connected to the electrode assembly (5710), a second collector plate (5750), an electrode terminal (5741), a vent plate (5742), and an insulating tape (5780). Here, the insulating tape (5780) may correspond to the insulating tape (5120) described above with reference to FIGS. 24 to 29. For example, the insulating tape (5780) may include a body portion (5782) having a ring shape centered on a central hole, and a leg portion (5784) composed of two or more rods arranged radially.

[0304] The body of the insulating tape (5780) may include a body (5782) that insulates between the core of the electrode assembly (5710) and the first collector plate (5730), and a leg (5784) extending from the body (5782). In one embodiment, the central hole of the body (5782) may be positioned corresponding to an empty core of the electrode assembly (5710). The leg (5784) of the insulating tape (5780) may be formed by radially arranging two or more rods centered on the body (5782). Here, at least two of the two or more rods may be formed to face each other.

[0305] In Fig. 30, the vent plate (5742) is shown as being positioned on the upper side of the secondary battery and the electrode terminal (5741) is shown as being positioned on the lower side of the secondary battery, but this is not limited thereto. Depending on the usage environment or requirements of the secondary battery, the vent plate (5742) and the electrode terminal (5741) may be changed to be positioned on the lower side and upper side of the secondary battery, respectively.

[0306] An electrode assembly (5710) is formed by winding a first electrode (5711a, 5711b), a separator (5713), and a second electrode (5712a, 5712b) into a cylindrical jelly roll state with an empty core. The first electrode (5711a, 5711b) and the second electrode (5712a, 5712b) include a coated portion (5711a, 5712a) in which an active material is applied to both sides of a substrate each formed of a thin metal plate, and a non-coated portion (5711b, 5712b) in which the substrate is exposed because the active material is not applied.

[0307] The first electrode (5711a, 5711b) may be an electrode corresponding to a positive or negative electrode in a secondary battery. The second electrode (5712a, 5712b) may be an electrode corresponding to a pole opposite to the first electrode (5711a, 5711b). For example, if the first electrode (5711a, 5711b) is a positive electrode, the second electrode (5712a, 5712b) may be a negative electrode. Conversely, if the first electrode (5711a, 5711b) is a negative electrode, the second electrode (5712a, 5712b) may be a positive electrode.

[0308] For example, the first electrode (5711a, 5711b) may form a positive electrode by coating a positive electrode active material on an aluminum (Al) substrate, and the second electrode (5712a, 5712b) may form a negative electrode by coating a negative electrode active material on a copper (Cu) substrate. The non-coated portion (5711b) of the first electrode and the non-coated portion (5712b) of the second electrode are respectively provided at opposite ends of the electrode assembly (5710) in the winding axis direction, but electrode terminals (5741) and a case (5720) having different polarities in the same direction are provided together. A vent plate (5742) is positioned on the opposite side of the electrode terminal (5741).

[0309] The case (5720) is formed in a cylindrical shape to house the electrode assembly (5710), and the electrode terminal (5741) and the vent plate (5742) are provided at each of the axial ends of the case (5720) so as to face each other.

[0310] According to one embodiment of the present disclosure, the diameter of the case (5720) may be 40 mm to 50 mm.

[0311] The electrode terminal (5741) is connected to the first electrode (5711a, 5711b) through the first collector plate (5730) via a rivet (5743), and the case (5720) is connected to the second electrode (5712a, 5712b) through the second collector plate (5750). At this time, the vent plate (5742) is electrically separated from the second collector plate (5750) and the case (5720) and has no polarity.

[0312] An electrode terminal (5741) connected to a first electrode (5711a, 5711b) of an electrode assembly (5710) inserted into a case (5720) from the outside is installed on one side of the case. The case (5720) has a partially open through hole (5721) on one side.

[0313] For example, the electrode terminal (5741) may be installed in a rivet structure in a through-hole (5721) of the case (5720). For this purpose, the electrode terminal (5741) may be connected to a rivet (5743). One end of the rivet (5743) is welded to the first collector plate (5730) and is positioned to penetrate the through-hole (5721). The electrode terminal (5741) is connected to the rivet (5743) and is positioned on the outside of the case (5720). The electrode terminal (5741) may be formed to protrude beyond the outer surface of the case (5720) around the through-hole (5721) and may be used as a positive electrode terminal. At this time, the first collector plate (5730) becomes a positive electrode collector plate.

[0314] At this time, the first collector plate (5730) is electrically connected to the uncoated portion (5711b) of the first electrode through a rivet (5743) and is electrically and mechanically connected to the electrode terminal (5741). The first collector plate (5730) is electrically connected to the electrode terminal (5741) in a structure that reduces resistance by contacting most of the uncoated portion (5711b) of the first electrode. The rivet (5743) included in the electrode terminal (5741) is installed in a state of electrical insulation from the case (5720) while forming a gas-tight structure with respect to the electrolyte by interposing an insulator (5723) in the through hole (5721).

[0315] Here, the insulator (5723) may be made of a polymer including ethylene propylene rubber (EPDM), polypropylene (PP), polyimide (PI), polyethylene terephthalate (PET), polycarbonate (PC), or a combination thereof.

[0316] As another example, the insulator (5723) may be made of a ceramic material including epoxy resin, alumina (Al2O3), zirconia (ZrO2), aramid fiber, Nomex, or a combination thereof. However, the material of the insulator (5723) is not limited to the materials listed above, and may include various materials with excellent plasticity and insulating properties, depending on the selection.

[0317] In one embodiment, the first collector plate (5730) may include a metal plate (5731) including at least one bridge (5732). For example, the first collector plate (5730) may be formed of a conductive metal, specifically, a conductive metal such as nickel, aluminum, copper, silver, zinc, tin, stainless steel (e.g., SUS), nickel-plated steel, or a combination (alloy) thereof. In addition, the metal plate (5731) and the bridge (5732) constituting the first collector plate (5730) may be made of the same material and form an integral body.

[0318] Here, the bridge (5732) of the first collector plate (5730) may be configured to be ruptured when a current exceeding a set value flows. For example, the bridge (5732) normally operates as a part of a circuit in which current flows, but when an excessive amount of current flows, it may function as a fuse that melts due to the generated heat and blocks the circuit.

[0319] An insulating member (5745) may be attached to one side of the first collector plate (5730). Specifically, a secondary battery according to one embodiment of the present disclosure may further include an insulating member (5745) disposed on the other side opposite to one side of the electrode assembly (5710) on which the insulating tape (5780) is disposed.

[0320] An insulating member (5745) may be interposed between the first collector plate (5730) and the case (5720) or between the non-conductive portion (5711b) of the first electrode and the case (5720) to electrically insulate each component. In one embodiment, a central portion of the insulating member (5745) may include a perforation (5746) corresponding to the shape of the rivet (5743) so that the rivet (5743) may come into contact with the first collector plate (5730). In addition, the insulating member (5745) may include a side wall (57457) so as to surround a portion of the electrode assembly (5710).

[0321] Additionally, the case (5720) has a fully open opening (5722) to allow the electrode assembly (5710) to be inserted into the other side. The vent plate (5742) seals the opening (5722) after the electrode assembly (5710) is inserted into the case (5720) and is electrically isolated from the case (5720).

[0322] At this time, the second collector plate (5750) is electrically connected to the non-conductive portion (5712b) of the second electrode and is electrically connected to the case (5720). The second collector plate (5750) is connected to the case (5720) in a structure that reduces resistance by contacting most of the non-conductive portion (5712b) of the second electrode.

[0323] The second collector plate (5750) includes a bottom portion (5751) welded to the non-coated portion (5712b) of the second electrode, and wing portions (5752) formed adjacent to the bottom portion (5751) and welded to the beading portion (5729). The second collector plate (5750) is formed by cutting and bending a circular plate, and each of the bottom portions (5751) and wing portions (5752) is provided in multiple numbers and arranged alternately along the circumferential direction. In one embodiment, the wing portions (5752) can be repeatedly formed by bending the axial direction (upward) and radial direction (outer) of the electrode assembly (5710).

[0324] In one embodiment, when the non-coated portion (5712b) of the second electrode and the bottom portion (5751) of the second collector plate (5750) are welded, the bottom portion (5751) can form a welding line in the diametrical direction of the second collector plate (5750). Accordingly, the bottom portion (5751) can be evenly connected along the circumferential direction in the area of ​​the non-coated portion (5712b) of the second electrode, and the wing portion (5752) can be evenly connected along the circumferential direction in the area of ​​the beaded portion (5729). This can enable a uniform current flow along the circumferential direction in the entire area of ​​the beaded portion (5729) of the case (5720) in the non-coated portion (5712b) of the second electrode.

[0325] In addition, the second collector plate (5750) has a hole (5753) in the center, so that deformation caused by welding of the bottom portion (5751) and the non-conductive portion (5712b) of the second electrode, and vibration and shock that may be transmitted between the wing portion (5752) and the bottom portion (5751) can be absorbed and mitigated. The hole (5753) may have a size that can absorb vibration and shock without increasing current resistance between the wing portion (5752) and the bottom portion (5751).

[0326] The vent plate (5742) is electrically isolated from the second collector plate (5750) and is installed in the opening (5722) of the case (5720) through a crimping process. Alternatively, the vent plate (5742) is installed in the opening (5722) of the case (5720) through a welding process. Due to the connection of the second collector plate (5750), the case (5720) can be used as a negative terminal. In this case, the second collector plate (5750) becomes a negative collector plate.

[0327] The vent plate (5742) may form a notch (5744) on its inner surface. The notch (5744) may be cut open to release internal pressure of the secondary battery to the outside when an abnormal event occurs in the secondary battery, thereby preventing a secondary explosion. Specifically, the notch (5744) may be formed to receive concentrated internal pressure in the event of an abnormal event, thereby enabling easy cutting. The notch (5744) may be formed over the entire circumferential area of ​​the vent plate (5742), or may be formed in multiple pieces spaced apart at set intervals.

[0328] A gasket (5760) is interposed between the second collector plate (5750) and the vent plate (5742) and between the second collector plate (5730) and the case (5720) to provide a sealing effect through a beading portion (5729) or a clamping process. In addition, the gasket (5760) can form a gastight structure for the electrolyte between the second collector plate (5730) and the opening (5722) of the case (5720).

[0329] For example, the gasket (5760) may include, but is not limited to, a polymer material or ceramic such as polyvinyl chloride (PVC), polytetrafluoroethylene (PTFE or Teflon), polyethylene (PE), epoxy resin, silicone, polyvinylidene fluoride (PVDF), polypropylene (PP), polyacrylonitrile (PAN), or polyethylene oxide (PEO), and may correspond to any one of suitable compounds used as an insulating material in the art.

[0330] The finishing tape (5790) may be attached to wrap the outer surface of the jelly roll of the electrode assembly (5710) at least 24 times. In addition, the electrode assembly (5710) may be inserted into the case (5720) with the finishing tape (5790) attached, and the finishing tape (5790) may be positioned between the electrode assembly (5710) and the case (5720). Accordingly, in the secondary battery after assembly, the electrode assembly (5710) does not move in the up-and-down or front-back direction inside the case (5720), thereby preventing separation of the terminal or damage to the element, and even in a state where the electrode assembly (5710) expands due to charging and discharging, cracks in the case (5720) or the electrode assembly (5710) due to excessive expansion of the electrode assembly (5710) may be suppressed.

[0331] A secondary battery according to one embodiment of the present invention can be applied to automobiles, mobile phones, and / or various types of electrical devices, but the present invention is not limited thereto.

[0332] In addition, the description of the configuration is the same as the description described above with reference to FIGS. 24 to 29.

[0333] Figure 31 is a flowchart showing an example of a method for manufacturing a secondary battery according to the present disclosure.

[0334] A method for manufacturing a secondary battery according to one embodiment of the present invention (5800) may be disclosed by forming an electrode assembly by stacking a first electrode, a separator, and a second electrode and then winding them (S5810). According to one embodiment of the present disclosure, the first electrode includes a first active material portion coated with a mixture layer along the winding direction and a first non-coated portion not coated with the mixture layer, and the first non-coated portion may include a plurality of independently bendable segments. According to one embodiment, the plurality of segments of the electrode assembly may be formed around the core portion.

[0335] The step of forming an electrode assembly (S5810) may include a step of forming a substrate tab by bending a plurality of segments along the radial direction of the electrode assembly. According to one embodiment of the present disclosure, the substrate tab includes a welding portion for welding with a current collector, and the body of the insulating tape may be placed in an area of ​​the substrate tab excluding the welding portion.

[0336] Thereafter, an insulating tape may be placed on one side of the electrode assembly (S5820). Here, the insulating tape may include a body portion that insulates between the core portion of the electrode assembly and the collector plate, and a leg portion that extends from the body portion and is interposed between the outer surface of the electrode assembly and the case.

[0337] According to one embodiment, the body of the insulating tape may be a ring shape having an outer diameter of 5 mm to 20 mm centered around a central hole. The core of the electrode assembly may include a through hole, and the step of placing the insulating tape (S5820) may include a step of placing the central hole of the body at a position corresponding to the through hole. In addition, the step of placing the insulating tape (S5820) may include a step of placing the insulating tape such that the body of the insulating tape covers a notch of the current collector. In addition, according to one embodiment, one of the two sides of the body portion facing the current collector may be coated with an adhesive layer.

[0338] According to one embodiment, the leg portion of the insulating tape may include two or more rods, two of which may be formed to face each other. The width of each of the two or more rods may be from 1 mm to 10 mm. The length of each of the two or more rods may be from 1 mm to 115 mm.

[0339] Thereafter, a current collector plate may be placed on the insulating tape (S5830). In one embodiment, the step of placing the current collector plate (S5830) may include a step of welding the current collector plate and the electrode assembly. In addition, in one embodiment, the step of placing the current collector plate (S5830) may include a step of placing the current collector plate such that the body of the insulating tape covers the notch of the current collector plate.

[0340] Thereafter, the electrode assembly, insulating tape, and collector plate may be inserted into the case through an opening on one side of the case and built into the case (S5840). In one embodiment, the diameter of the case may be 40 mm to 50 mm.

[0341] A method for manufacturing a secondary battery (5800) according to one embodiment of the present disclosure may further include a step of placing an insulating member on one side of an electrode assembly opposite to the other side on which an insulating tape is placed.

[0342] A method for manufacturing a secondary battery (5800) according to one embodiment of the present disclosure may further include a step of inserting a welding rod through a through-hole included in a core portion of an electrode assembly and a central hole included in a body portion of an insulating tape. Thereafter, the inserted welding rod may weld the electrode assembly and the electrode terminal of the secondary battery to each other. The welding method using the welding rod is not limited, and various welding methods capable of joining the electrode terminal and the electrode assembly may be used. For example, welding may be performed by not only laser welding but also ultrasonic welding, brazing, laser brazing, welding, soldering, etc.

[0343] Although the present invention has been described above with reference to limited embodiments and drawings, the present invention is not limited thereto, and it is obvious that various modifications and variations are possible within the scope of the technical idea of ​​the present invention and the equivalent scope of the patent claims to be described below by a person having ordinary skill in the art to which the present invention pertains.

Claims

1. A first electrode including a first substrate layer and a first composite layer coated on both sides of the first substrate layer; A second electrode comprising a second substrate layer and a third substrate layer, an insulating layer disposed between the second substrate layer and the third substrate layer, a second composite layer coated on the second substrate layer, and a third composite layer coated on the third substrate layer; and A separator disposed between the first electrode and the second electrode Including, The above insulating layer is, An electrode assembly that extends and is exposed from one side of the second substrate layer and the third substrate layer.

2. In paragraph 1, An electrode assembly, wherein the insulating layer comprises polyethylene terephthalate (PET).

3. In paragraph 1, At least a portion of the second substrate layer includes a non-coated portion on which the second composite layer is not coated, An electrode assembly, wherein at least a portion of the third substrate layer includes a non-coated portion on which the third composite layer is not coated.

4. In paragraph 1, The first electrode, the separator disposed on the first electrode, and the second electrode disposed on the separator are formed by winding around the core, An electrode assembly, wherein the length of an imaginary curve extending from a first tip positioned close to the core of the second substrate layer and the third substrate layer to a position parallel to the second tip positioned close to the core of the first substrate layer in a shape similar to the shape in which the second electrode is wound is longer than the shortest distance from the core to the first electrode.

5. In paragraph 1, The first electrode, the separator disposed on the first electrode, and the second electrode disposed on the separator are formed by winding around the core, The above first substrate layer is, Including a first upper plain portion exposed to the outside of the first composite layer in the axial direction of the core portion, An electrode assembly, wherein the first upper portion includes a plurality of first segments formed by notching at least a portion of the first upper portion.

6. In paragraph 1, The first electrode, the separator disposed on the first electrode, and the second electrode disposed on the separator are formed by winding around the core, The above second substrate layer is, Including a second upper plain portion exposed to the outside of the second composite layer in the axial direction of the core portion, The third substrate layer is: It includes a third upper plain portion that is combined with the second upper plain portion and is exposed to the outside of the third composite layer in the axial direction of the core portion, An electrode assembly comprising a plurality of second segments formed by at least a portion of the second upper non-conductive portion and the third upper non-conductive portion being notched while being joined.

7. In paragraph 1, An electrode assembly wherein the area of ​​the insulating layer is larger than the area of ​​the second substrate layer.

8. In paragraph 1, The above electrode assembly is formed by winding a first electrode, a separator, and a second electrode, An electrode assembly, wherein the width of the insulating layer in the exposed section of the insulating layer is greater than or equal to the width of the second substrate layer and the width of the third substrate layer.

9. In paragraph 8, An electrode assembly, wherein the insulating layer includes a first exposed portion exposed in one width direction of the second substrate layer and the third substrate layer in the exposed section.

10. In paragraph 8, An electrode assembly, wherein the above-mentioned exposure section is located at the terminal end of the core side of the electrode assembly.

11. In paragraph 9, The second electrode includes a second non-coated portion on which a second composite layer is not applied on the multilayer substrate, An electrode assembly wherein the second exposed portion is positioned in an opposite direction to the first exposed portion.

12. In paragraph 11, An electrode assembly, wherein a second substrate tab is formed on at least a portion of the second non-conductive portion.

13. In paragraph 8, The first electrode includes a first non-coated portion to which the first composite layer is not applied, An electrode assembly, wherein a first substrate tab is formed on at least a portion of the first non-conductive portion.

14. In paragraph 13, An electrode assembly, wherein the first substrate tab is bent toward the core direction of the electrode assembly.

15. Electrode assembly of paragraph 1; A current collector plate arranged on one side of the electrode assembly; a case containing the electrode assembly; and Including an insulating tape placed between the electrode assembly and the current collector, The above insulating tape, A body part that insulates between the core part of the electrode assembly and the collector plate; and A secondary battery including a leg portion extending from the body portion and interposed between the outer surface of the electrode assembly and the case.

16. In paragraph 15, At least a portion of the first non-conductive portion is bent along the radial direction of the electrode assembly to form a substrate tab, The above-mentioned substrate tab includes a welding portion for welding with the above-mentioned current collector plate, A secondary battery, wherein the body of the above insulating tape is placed in an area of ​​the above substrate tab excluding the welding area.

17. In paragraph 15, A secondary battery, wherein the body portion of the insulating tape is a ring-shaped body having an outer diameter of 5 mm to 20 mm centered on a central hole.

18. In paragraph 15, The core of the above electrode assembly includes a through hole, A secondary battery in which the central hole of the above body part is positioned corresponding to the through hole.

19. In paragraph 15, A secondary battery, wherein the body of the insulating tape is arranged to cover the notch of the current collector plate.

20. In paragraph 15, The above leg portion includes two or more rods, Two of the above two or more loads are formed to face each other, Secondary battery.

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