Low-resistance cable-type cell without electrode tab

Abstract

The present invention relates to a low-resistance cable-type cell without an electrode tab, wherein an internal member that forms the outermost layer of the cable-type cell can function as an electrode tab without the need to form an electrode tab for an external electrode, by configuring the internal member only with a conductive layer so as to solve a problem of slowing down the electron transfer speed due to a battery resistance increase caused by the increase of the length of a battery according to the characteristics of a linear structure of a cable-type cell when a battery cell is manufactured to have electrode tabs formed at both ends thereof. The cable-type cell provides a shortest path through which electrons can pass from an active material layer of an electrode to an electrode tab, thereby confirming low resistance characteristics.

Description

Cable-type cell without low-resistance electrode tabs

[0001] This application claims the benefit of priority to Korean Patent Application No. 2023-0095051, filed July 21, 2023, the entire contents of which are incorporated herein by reference.

[0002] The present invention relates to a cable-type cell without low-resistance electrode tabs. Specifically, due to the linear structure characteristic of a cable-type cell in which electrode tabs are formed at both ends, as the length of the cell increases, the distance electrons travel from the electrodes to the electrode tabs increases, which causes problems such as increased resistance of the cell and decreased electron movement speed. In order to solve such problems, the present invention relates to a cable-type cell without low-resistance electrode tabs, in which an internal member constituting the outermost part of the cable-type cell is formed of a conductive layer, thereby enabling the internal member to function as an electrode tab without the need for separate formation of electrode tabs of an external electrode.

[0003] As the safety of rechargeable lithium secondary batteries is rapidly improving and their capacity is increasing, the types of devices that use the lithium secondary batteries as an energy source are increasing.

[0004] For example, the lithium secondary battery is not only widely used as an energy source for small, multi-functional products such as wireless mobile devices or wearable devices worn on the body, but is also used as an energy source for electric vehicles and hybrid electric vehicles, which are presented as alternatives to existing gasoline and diesel vehicles that cause air pollution, or as a medium- to large-sized battery pack for use as an energy storage system (ESS).

[0005] The above lithium secondary batteries are classified into cylindrical and prismatic battery cells, in which the electrode assembly is built into a cylindrical or prismatic metal can, and pouch-type battery cells, in which the electrode assembly is built into a pouch-type case made of aluminum laminate sheet, depending on the shape of the battery case. Among these, pouch-type battery cells have the advantages of relatively large capacity and the ability to be structurally modified.

[0006] Various wearable computer technologies and applications utilizing these secondary batteries as a power source are being developed and announced. Furthermore, electronic devices such as cell phones and laptops are being designed with curved surfaces for ergonomics. Accordingly, the secondary batteries that power these electronic devices also need to be formed with various shapes, such as curved surfaces, to accommodate the specific configurations of the devices.

[0007] To match the capacity and voltage specifications of these devices, multiple pouch cells can be connected in parallel or in series to form packs. However, this increases the thickness and volume of the entire pouch cell, reducing its flexibility. Furthermore, mechanical deformation can directly apply mechanical stress to the battery components, potentially damaging the pouch cell and degrading its performance.

[0008] In response to this, the concept of a linear cell, which is a cell with a very large ratio of length to cross-sectional diameter, was proposed.

[0009] Figure 1 is a cross-sectional view of a conventional cable-type cell.

[0010] Referring to FIG. 1, the cable-type cell may include an internal electrode (200) including an internal electrode support (100), a first internal current collector (210) formed by being sequentially wound around the internal electrode support (100), and a first internal active material layer (220).

[0011] An external separation layer (300) can be formed outside the inner electrode (200).

[0012] An external electrode (400) including an external active material layer (420) and an external current collector (410) can be formed outside the external separation layer (300).

[0013] An internal member (600) including a first internal member layer (610), a second internal member layer (620), a third internal member layer (630), and a fourth internal member layer (640) can be formed outside the external electrode (400).

[0014] The first internal member layer (610) may be an adhesive layer for bonding the external current collector (410) and the internal member (600).

[0015] The second internal member layer (620) may be formed with a metal layer for moisture and / or oxygen blocking.

[0016] The third internal member layer (630) and / or the fourth internal member layer (640) may be formed as an insulating layer for insulation.

[0017] The above adhesive layer may be formed of one or two or more of polypropylene, polycarbonate, polyethylene, styrene butadiene rubber, sodium carboxymethyl cellulose, polyvinylidene fluoride, polyvinylidene fluoride copolymer, polytetrafluoroethylene, polystyrene, polyacrylonitrile, polyimide, polyacrylic acid, sodium polyacrylate, polyvinyl alcohol, sodium alginate, polymethacrylic acid, and carboxymethyl chitosan.

[0018] The present invention comprises an internal member, which is an insulator formed on the outer surface of the external current collector to protect the electrode from moisture in the air and external impact. The internal member may be a conventional polymer resin including a moisture barrier layer. In this case, aluminum or a liquid crystal polymer with excellent moisture barrier performance may be used as the moisture barrier layer.

[0019] The polymer resin may include one or two or more selected from the group consisting of PET (polyethylene terephthalate), PVC (polyvinyl chloride), HDPE (high density polyethylene), and epoxy resin.

[0020] Figure 2 is a perspective view of a bidirectional electrode tab of a conventional cable-type cell.

[0021] Referring to Fig. 2, electrode tabs are formed on both end surfaces of a conventional cable-type cell and can be connected to an external terminal.

[0022] The electrode tab protruding at the lower part of Fig. 2 may be an internal electrode tab (230) of the internal electrode.

[0023] The electrode tab protruding at the upper part of Fig. 2 may be an external electrode tab (430) of the external electrode.

[0024] The inner electrode tab (230) may be formed to extend from the inner current collector. The outer electrode tab (430) may be formed to extend from the outer current collector. Accordingly, a unidirectional cable-type cell may be formed in which the inner electrode tab and the outer electrode tab protrude from one end of the cable-type cell.

[0025] A bidirectional cable-type cell can be formed in which internal electrode tabs (230) and / or external electrode tabs (430) are formed at both ends of the cable-type cell.

[0026] A bidirectional cable-type cell can be formed in which internal electrode tabs (230) and / or external electrode tabs (430) are formed at both ends of the cable-type cell.

[0027] The internal member is configured in the form of a sheet including an aluminum laminate layer, and the internal member has a structure that wraps around the entire internal electrode (200), external separation layer (300), and external electrode (400) that are sequentially wound around the internal electrode support.

[0028] Accordingly, the electrode tabs of the inner electrode (200) and the outer electrode (400) are formed in a strip shape by welding separately from the current collectors of the inner electrode (200) and the outer electrode (400) to protrude at both ends of the cable-type cell.

[0029] Due to the linear structure of these cable-type cells, the electrode tabs of the electrodes can only be formed at both ends of the battery. As the length of the battery increases, the distance that electrons travel from the electrodes to the electrode tabs increases, which causes a problem in that the rate characteristics related to electron mobility deteriorate due to an increase in battery resistance.

[0030] In addition, in the case of a unidirectional cable-type cell, since the inner electrode tab and the outer electrode tab are formed adjacently, there is a problem of short circuit due to contact between the two electrode tabs.

[0031] Therefore, by using a tabless structure in which an electrically conductive material that acts as a positive electrode tab is applied to the outermost packaging of a cable-type cell, the shortest path for electrons to flow from the active material layer of the electrode to the electrode tab is provided, and the resistance of the cable-type cell is minimized regardless of the length of the linear battery, thereby balancing the length of the battery and the degradation of electron transport characteristics.

[0032] Korean Patent Publication No. 2259381 discloses a flexible secondary battery comprising: an electrode support; a sheet-shaped inner electrode spirally wound around the outside of the electrode support; a sheet-shaped first solid electrolyte layer spirally wound around the outside of the inner electrode; a sheet-shaped bipolar electrode spirally wound around the outside of the first solid electrolyte layer; a sheet-shaped second solid electrolyte layer spirally wound around the outside of the bipolar electrode; and a sheet-shaped outer electrode spirally wound around the outside of the second solid electrolyte layer, wherein the first solid electrolyte layer and the second solid electrolyte layer include an organic solid electrolyte, and wherein the inner electrode and the outer electrode have insulating coating portions at both longitudinal ends of one side facing the first solid electrolyte layer and the second solid electrolyte layer, respectively, and the bipolar electrode has insulating coating portions at both longitudinal ends of both side surfaces.

[0033] However, there has never been a cable-type cell technology applied in which the inner member for applying the outermost part of the cable-type cell of the present invention as an electrode tab of an external electrode has a structure that exposes the external electrode.

[0034] Korean Patent Publication No. 2128094 discloses a cable-type secondary battery including a cable-type electrode assembly including an inner electrode, a separation layer formed to surround the outer surface of the inner electrode and prevent short-circuiting of the electrode, and an outer electrode formed to surround the separation layer; and a sheet-shaped packaging formed by being spirally wound to surround the outer surface of the cable-type electrode assembly.

[0035] However, there has been no disclosure regarding a cable-type cell technology in which an internal member exposing the external electrode of the present invention is formed.

[0036] Japanese Patent Application Publication No. 2016-066520 discloses a storage device having a structure in which a storage sheet composed of a positive electrode / separator / negative electrode is spirally wound around a wire structure, a structure in which a gap is formed between the wound storage sheets, and an exposed portion is formed on the positive and / or negative electrode sheets of the storage sheets and is used as a terminal by being exposed to the outside of the storage sheets.

[0037] However, there has been no disclosure regarding a cable-type cell technology in which an internal member exposing the external electrode of the present invention is formed.

[0038] Japanese Patent Application Publication No. 2021-026957 discloses a cathode having a bundle of carbon fibers and a metal wire inserted into the bundle along the longitudinal direction of the bundle, and a pin-type secondary battery including the same.

[0039] However, a cable-type cell technology that applies an internal member that is partially wound with a gap in order to apply the outermost part of the cable-type cell of the present invention as an electrode tab of an external electrode has never been applied.

[0040] Therefore, when manufacturing a battery cell using both ends where electrode tabs are formed due to the linear structure characteristic of a cable-type cell, the distance that electrons move from the electrodes to the electrode tabs increases as the length of the battery increases. Therefore, in order to solve the problem of electron movement speed due to increased battery resistance, development of a cable-type cell without electrode tabs with low resistance is required, in which the non-conductive material of the internal member forming the outermost part of the cable-type cell is removed and the outermost part of the cable-type cell is formed with a conductive layer, so that the internal member can function as an electrode tab without the need to form an electrode tab of an external electrode.

[0041] The present invention is intended to solve the above problems, and when manufacturing a cable-type cell in which electrode tabs are formed at both ends, the resistance of the cell increases and the electron movement speed decreases because the distance of movement of electrons from the electrodes to the electrode tabs increases as the length of the cell increases due to the linear structure characteristic of the cable-type cell. In order to solve this problem, the present invention provides a cable-type cell without electrode tabs having low resistance, in which the internal member can function as an electrode tab without the need to form an electrode tab of an external electrode by removing a non-conductive material of an internal member constituting the outermost part of the cable-type cell and forming the outermost part of the cable-type cell with a conductive layer.

[0042] In addition, since the pouch-type inner material, which is the outermost packaging of the cable-type cell, is conductive, the purpose is to provide the shortest path for electrons to move from the active material layer of the electrode to the electrode tab by using a cable-type tabless structure that acts as an electrode tab of the external electrode.

[0043] In addition, in order to solve the problem of deterioration of electron movement characteristics as the length of the existing cable-type cell increases, the present invention aims to provide a cable-type cell including a cable-type tabless structure that can increase the length of the battery without restriction.

[0044] To achieve this purpose, a cable-type cell without a low-resistance electrode tab according to the present invention comprises an internal electrode support, one or more internal electrodes sequentially spirally wound around the internal electrode support, a cable-type electrode assembly having an external separation layer and an external electrode structure, and an internal member accommodating the cable-type electrode assembly, wherein the internal member may be composed of a conductive material.

[0045] The above-mentioned built-in member may be formed of a single layer or two or more laminated conductive layers.

[0046] The above-mentioned internal member can be in contact with the above-mentioned external electrode.

[0047] The above-mentioned internal member can function as an electrode tab of the above-mentioned external electrode.

[0048] The inner electrode includes a first inner electrode, and the first inner electrode includes a first inner current collector and a first inner active material layer formed on one surface of the first inner current collector, and may be in the form of a monocell including the first inner electrode, the outer separation layer, and the outer electrode.

[0049] The above external electrode may include an external current collector and an external active material layer formed on one surface of the external current collector, and may be in the form of a monocell including the first internal electrode, the external separation layer, and the external electrode.

[0050] The inner electrode may include an inner separation layer formed by spirally winding on the outside of the first inner electrode and a second inner electrode formed by spirally winding on the outside of the inner separation layer, and may be in the form of a bi-cell including the first inner electrode, the inner separation layer, the second inner electrode, the outer separation layer, and the outer electrode.

[0051] The second internal electrode may include a second internal current collector and a second-first internal active material layer formed on both sides of the second internal current collector, and a second-second internal active material layer.

[0052] The first internal electrode and the external electrode may have the same pole, and the second internal electrode may have a different pole from the first internal electrode and the external electrode.

[0053] If the first internal electrode and the external electrode are positive electrodes, the second internal electrode may be negative electrodes, and if the first internal electrode and the external electrode are negative electrodes, the second internal electrode may be positive electrodes.

[0054] The inner separation layer and the outer separation layer may each be an electrolyte layer or a separator.

[0055] The above-mentioned internal member may be in a form that wraps around both end surfaces of the cable-type cell.

[0056] When the cable-type cell is in the form of a monocell, the internal member may be added to cover the external electrodes and a portion of the external separation layer exposed at both ends of the cable-type electrode assembly.

[0057] When the cable-type cell is in the monocell form, a non-conductive internal electrode sealant layer may be formed from a portion of the external separation layer where the internal member is not formed to the first internal active material layer.

[0058] At least one of both ends of the cable-type electrode assembly may have an internal electrode tab formed in a portion of the first internal current collector where the built-in member and the sealant layer are not formed.

[0059] An internal electrode tab sealant layer may be formed at the connection portion between the internal electrode tab and the first internal current collector.

[0060] When the cable-type cell is in the form of a bi-cell, the built-in member may be added to cover the outer electrode, the inner electrode, a portion of the outer separation layer, and a portion of the inner separation layer exposed at both ends of the cable-type electrode assembly.

[0061] When the cable-type cell is in the bi-cell form, a non-conductive internal electrode sealant layer may be formed from a portion of the external separation layer to which the built-in member is not added to the 2-1 internal active material layer, and a non-conductive sealant layer may be formed from a portion of the internal separation layer to which the built-in member is not added to the 2-2 internal active material layer.

[0062] At one or more ends of the cable-type electrode assembly, an internal electrode tab may be formed extending from the second internal current collector on which the internal member and the internal electrode sealant layer are not formed.

[0063] The above internal electrode sealant layer may include one or two or more selected from the group consisting of polypropylene, polypropylene-acrylic acid copolymer, polyethylene-acrylic acid copolymer, chlorinated polypropylene, polypropylene-butylene-ethylene terpolymer, polyethylene, polyethylene, and ethylene-propylene copolymer.

[0064] The cross-section of the above cable-shaped cell may be any one of circular, elliptical, triangular, rectangular, square, rectangular, polygonal, and amorphous shapes.

[0065] The above-mentioned built-in member can accommodate the cable-type electrode assembly in a bag-like form.

[0066] It may include an exterior member formed on the outer surface of the above-mentioned internal member and exposing only a portion of the above-mentioned internal member.

[0067] The above outer member can wrap the inner member formed at both ends of the cable-type cell.

[0068] The above outer member can wrap around both ends of the cable-type cell, excluding the internal electrode tab.

[0069] To achieve this purpose, a cable-type cell without electrode tabs of low resistance according to the present invention comprises a cable-type electrode assembly having a structure of two or more inner electrodes, an outer separation layer and an outer electrode that are formed to surround the outer surfaces of the two or more inner electrodes and are sequentially spirally wound, and an internal member that accommodates the cable-type electrode assembly, wherein the internal member may be conductive.

[0070] The above internal electrodes may be arranged such that two or more wire-shaped internal electrodes are in contact with each other in parallel, or two or more wire-shaped internal electrodes may be arranged in a twisted form.

[0071] The present invention can also be provided in a form in which various means for solving the above problem are combined.

[0072] As described above, the cable-type cell without a low-resistance electrode tab according to the present invention can implement low-resistance characteristics by providing the shortest path through which electrons can pass from the active material layer of the electrode to the electrode tab.

[0073] In addition, the resistance of the battery can be minimized regardless of the length of the cable-type cell, thereby minimizing the deterioration of electron transfer characteristics even when the length of the battery increases.

[0074] In addition, since the length can be increased without any performance restrictions on the cable-type cell in response to various length change requests according to the morphological requirements of electronic devices, customized battery production is possible to fit the shape of various electronic devices.

[0075] Figure 1 is a cross-sectional view of a conventional cable-type cell.

[0076] Figure 2 is a perspective view of a bidirectional electrode tab of a conventional cable-type cell.

[0077] Figure 3 is a schematic diagram of a cable-type cell in which an internal member, which is a conductive metal sheet, is reflected according to one embodiment of the present invention.

[0078] FIG. 4 is a schematic diagram of an electrode tab of a cable-type cell in which an internal member, which is a conductive metal sheet that serves as an electrode tab of an external electrode according to one embodiment of the present invention, is reflected.

[0079] FIG. 5 is a cross-sectional view of an end of a cable-type monocell reflecting an internal member which is a conductive metal sheet according to one embodiment of the present invention.

[0080] Fig. 6 is an end perspective view of a cable-type monocell reflecting an internal member which is a conductive metal sheet according to one embodiment of the present invention.

[0081] Fig. 7 is a BB cross-sectional view of a cable-type monocell reflecting an internal member which is a conductive metal sheet according to one embodiment of the present invention.

[0082] Fig. 8 is a CC cross-sectional view of a cable-type bicell reflecting an internal member which is a conductive metal sheet according to one embodiment of the present invention.

[0083] FIG. 9 is a schematic diagram of a cable-type cell of a plurality of internal electrodes, each of which reflects an internal member, which is a conductive metal sheet that serves as an electrode tab of an external electrode, according to one embodiment of the present invention.

[0084] Figure 10 is a graph showing the resistance between the external electrode and the external electrode tab according to the length of a conventional cable-type cell and a cable-type cell in which the internal member of the present invention is a metal layer.

[0085] Hereinafter, with reference to the attached drawings, embodiments of the present invention will be described in detail, so that those with ordinary skill in the art can easily implement the present invention. However, when describing the operating principles of preferred embodiments of the present invention in detail, if a detailed description of a related known function or configuration is judged to unnecessarily obscure the gist of the present invention, such detailed description will be omitted.

[0086] Additionally, the same drawing reference numerals are used for parts with similar functions and actions throughout the drawings. Throughout the specification, when a part is said to be connected to another part, this includes not only direct connections but also indirect connections with other elements intervening. Furthermore, inclusion of a component does not exclude other components unless specifically stated otherwise, but rather implies the inclusion of additional components.

[0087] Additionally, the description that concretizes or adds components may be applied to all inventions unless there are special limitations, and is not limited to the description of a specific invention.

[0088] Additionally, throughout the description and claims of the invention herein, the singular includes the plural unless otherwise stated.

[0089] Additionally, throughout the description and claims of the present invention, the term "or" includes "and" unless otherwise stated. Therefore, "comprising A or B" means all three cases of including A, including B, or including A and B.

[0090] The present invention is described in detail with examples according to the drawings.

[0091] Figure 3 is a schematic diagram of a cable-type cell reflecting a conductive metal sheet-type internal member according to one embodiment of the present invention.

[0092] Referring to FIG. 3, the cable-type cell includes an internal electrode support (100), one or more internal electrodes (200) sequentially spirally wound around the internal electrode support (100), an external separation layer (300), a cable-type electrode assembly (500) having an external electrode (400) structure, and an internal member (600) that accommodates the cable-type electrode assembly (500), and the internal member (600) may be composed of a conductive material.

[0093] Here, the above-mentioned spiral is expressed as spiral or helix in English, and is a general term for a shape similar to the shape of a general spring, with a shape that is twisted and turned over a certain range.

[0094] The above inner electrode, separation layer and outer electrode may have a strip structure extending in one direction.

[0095] The internal member (600) is composed of a conductive material, and may be composed of, for example, a metal sheet including aluminum, nickel, copper, and alloys thereof, which have excellent electrical conductivity.

[0096] The internal electrode (200) includes a first internal electrode, and the first internal electrode may include a first internal current collector (210) and a first internal active material layer (220) formed on the first internal current collector (210).

[0097] Each outer separation layer (300) may be an electrolyte layer or a separator.

[0098] The external electrode (400) may include an external current collector (410) and an external active material layer (420) formed on the external current collector (410).

[0099] A polymer layer (440) can be formed on the outer surface of the external current collector (410) in the external electrode (400).

[0100] The polymer layer (440) may be an adhesive layer for bonding the outer surface of the external collector (410) and the internal member (600).

[0101] The polymer layer (440) may be formed of one or two or more selected from the group consisting of polypropylene, polycarbonate, polyethylene, styrene butadiene rubber, sodium carboxymethylcellulose, polyvinylidene fluoride, polyvinylidene fluoride copolymer, polytetrafluoroethylene, polystyrene, polyacrylonitrile, polyimide, polyacrylic acid, sodium polyacrylate, polyvinyl alcohol, sodium alginate, polymethacrylic acid, and carboxymethyl chitosan.

[0102] The polymer material of the adhesive layer is not limited as long as it can combine the outer member and the inner member.

[0103] The above adhesive layer can be replaced with an adhesive.

[0104] The cable-type electrode assembly (500) may include an internal member (600) added to contact the opposite surface on which the external active material layer (420) is formed on the external current collector (410).

[0105] The internal electrode support (100) may be configured as an open structure with a space formed inside.

[0106] The internal electrode support (100) may be configured in the form of one or more spirally wound wires, one or more spirally wound sheets, twisted wires, linear wires, hollow fibers, or mesh-shaped support.

[0107] The above hollow fiber may be at least one selected from the group consisting of polyethylene, polypropylene, polytetrafluoroethylene, polyvinylidene fluoride, polyacrylonitrile, polyimide, polyethylene terephthalate, polyamide imide, polyester imide, polyether sulfone, and polysulfone.

[0108] The internal electrode support (100) may include two or more wire-shaped internal electrode supports wound in a spiral manner so as to intersect each other.

[0109] An internal electrode current collector core part, a lithium ion supply core part including an electrolyte, or a filling core part can be formed in a space formed inside the internal electrode support (100).

[0110] The above internal electrode current collector core part can be made of carbon nanotubes, stainless steel, aluminum, nickel, titanium, sintered carbon or copper; stainless steel surface-treated with carbon, nickel, titanium or silver; aluminum-cadmium alloy; non-conductive polymer surface-treated with a conductive material; or conductive polymer.

[0111] The above lithium ion supply core part may include a gel-type polymer electrolyte and a support.

[0112] The above electrolyte may be a non-aqueous electrolyte using ethylene carbonate (EC), propylene carbonate (PC), butylene carbonate (BC), vinylene carbonate (VC), diethyl carbonate (DEC), dimethyl carbonate (DMC), ethyl methyl carbonate (EMC), methyl formate (MF), gamma-butyrolactone (γ-BL), sulfolane, methyl acetate (MA), or methyl propionate (MP).

[0113] The above electrolyte may include an electrolyte selected from among solid electrolytes using PEO (polyethyleneoxide), PPO (polypropylene oxide), PEI (polyethylene imine), PES (polyethylene sulphide), or PVAc (polyvinyl acetate).

[0114] The above electrolyte may further include a lithium salt.

[0115] The above lithium salts are LiCl, LiBr, LiI, LiClO4, LiBF4, LiB 10 Cl 10 , LiPF6, LiCF3SO3, LiCF3CO2, LiAsF6, LiSbF6, LiAlCl4, CH3SO3Li, CF3SO3Li, (CF3SO2)2NLi, lithium chloroborane, lithium lower aliphatic carboxylic acid, and lithium tetraphenylborate, or a mixture of two or more thereof.

[0116] The above gel-type polymer electrolyte may use PEO (polyethyleneoxide), PVdF (polyvinylidene fluoride), PVdF-HFP (poly vinylidene fluoride-co-hexafluoropropylene), PMMA (polymethymetacrylate), PAN (polyacrylonitrile), or PVAc (polyvinyl acetate).

[0117] The first internal electrode may include a first internal current collector (210) and a first internal active material layer (220) formed on one surface of the first internal current collector (210), and the external electrode may include (400), an external current collector (410) and an external active material layer (420) formed on one surface of the external current collector (410).

[0118] A polymer film layer formed on at least one of the other surfaces of the first inner current collector (210) and the other surfaces of the outer current collector (410) may be further included. By adding the polymer film layer, the thickness of the thin first inner current collector (210) and the outer current collector (410) can be supplemented to support the active material layer. In addition, rather than increasing the thickness of the first inner current collector (210) and the outer current collector (410) themselves, since a flexible polymer film layer is added, the first inner current collector (210) and the outer current collector (410) can be easily deformed during the spiral winding process.

[0119] The above polymer film layer may be formed of one selected from the group consisting of polyolefin, polyester, polyimide, and polyamide, or a mixture of two or more thereof.

[0120] A polymer support layer (440) may be further formed on the surface of at least one of the first internal active material layer (220) and the external active material layer (420).

[0121] The above polymer support layer may be a porous polymer layer having a pore size of 0.01 μm to 10 μm and a porosity of 5 to 95%.

[0122] The polymer support layer may include a polar linear polymer, an oxide-based linear polymer, or a mixture thereof.

[0123] FIG. 4 is a schematic diagram of an electrode tab of a cable-type cell in which an internal member, which is a conductive metal sheet that serves as an electrode tab of an external electrode according to one embodiment of the present invention, is reflected.

[0124] Referring to FIG. 4, the built-in member (600) may be formed of a single layer or two or more laminated conductive layers. For example, the built-in member may be formed of a conductive layer having a single layer structure made of a conductive material, or may be formed of two or more laminated layers made of a conductive material.

[0125] The internal member (600) can come into contact with the external electrode (400).

[0126] The internal member (600) can function as an electrode tab of the external electrode (400).

[0127] In the above drawing 4, an internal electrode tab welding portion (231) is formed for connection with the internal electrode tab (230) of the internal electrode (200), and a terminal connection line (900) is connected to the internal electrode tab (230).

[0128] The above-mentioned internal member (600) made of the above-mentioned conductive layer can perform the role of a conventional external electrode tab (430).

[0129] That is, by forming an internal member (600) that performs the function of an external electrode tab (430) of an external electrode (400), electrode terminal connection is possible at the outer surface along the length direction of the cable-type cell and at both ends of the cable-type cell.

[0130] The internal electrode (200) forming the opposite pole to the external electrode (400) can be connected to the electrode terminal by the internal electrode tab (230) extended from the internal electrode current collector (210) through the internal electrode tab welding portion (231).

[0131] FIG. 5 is a cross-sectional view of an end of a cable-type monocell reflecting an internal member which is a conductive metal sheet according to an embodiment of the present invention, FIG. 6 is a perspective view of an end of a cable-type monocell reflecting an internal member which is a conductive metal sheet according to an embodiment of the present invention, and FIG. 7 is a BB cross-sectional view of a cable-type monocell reflecting an internal member which is a conductive metal sheet according to an embodiment of the present invention.

[0132] Referring to FIGS. 5 to 7, if the internal member (600) formed of a conductive sheet and performing the function of the external electrode tab of the external electrode (400) comes into contact with the internal electrode tab (230) of the internal electrode (200) at both ends of the cable-type cell, a short circuit may occur. To prevent this, an internal electrode sealant layer (240) is formed.

[0133] The inner electrode (200) includes a first inner electrode, and the first inner electrode includes a first inner current collector (210) and a first inner active material layer (220) formed on one surface of the first inner current collector (210), and a monocell shape including the first inner electrode, an outer separation layer (300), and an outer electrode (400) can be configured.

[0134] The external electrode (400) includes an external current collector (410) and an external active material layer (420) formed on one surface of the external current collector (410), and can form a monocell shape including the first internal electrode, the external separation layer (300), and the external electrode (400).

[0135] In Fig. 5, looking at a cross-sectional view of one end of the cable-type cell in the form of a monocell, an internal electrode support (100) is positioned at the very center, and in order from the center of the internal electrode support (100) outward, a first internal current collector (210), a first internal active material layer (220), an external separation layer (300), an external active material layer (420), an external current collector (410), and a conductive internal member (600) formed by contacting the external current collector (410) are added.

[0136] Looking at the end surface of the above monocell, the conductive internal member (600) can be formed by wrapping around the external current collector (410), the external active material layer (420), and a portion of the external separation layer (300) of a predetermined thickness.

[0137] In order to prevent a short circuit from occurring due to contact between the internal member (600) and the internal electrode (200), an internal electrode sealant layer (240) may be formed from the end of the external separation layer (300) where the internal member (600) is not added to the first internal active material layer (220).

[0138] The internal electrode tab (230) is formed by welding to the first internal current collector (210), and an internal electrode tab welding portion (231) connecting the end of the first internal current collector (210) and the internal electrode tab (230) can be formed.

[0139] An internal electrode tab sealant layer (232) may be formed to seal the internal electrode tab weld (231) in a non-conductive manner.

[0140] Additionally, a sealant layer for insulation may be additionally formed at the end of the inner support (600).

[0141] Referring to FIG. 5, it can be seen that the conductive internal member (600) is added while covering the external current collector (410), the external active material layer (420), and a portion of the external separation layer (300) of a predetermined thickness.

[0142] Referring to the circular cross-section perpendicular to the longitudinal direction of the cable-type cell illustrated in the upper part of Fig. 5, the inner member (600) located at the outermost portion while being added while wrapping around the outer current collector (410), the outer active material layer (420), and a portion of the outer separation layer (300) of a predetermined thickness is illustrated as having the largest diameter.

[0143] The built-in member (600) extends to a part of the internal electrode tab (230), and considering the thickness of the built-in member itself, the area between the first and second circles on the outside in the circular cross-section, and between the second and third circles on the outside, refers to the built-in member (600).

[0144] The material located on the inside of the internal member (600) and between the third and fourth circles from the outside is the internal electrode sealant layer (240). The internal electrode sealant layer (240) is added from the end of the external separation layer (300) where the internal member (600) is not added to the first internal active material layer (220).

[0145] The circular shape of the internal electrode tab weld sealant layer (232) for non-conductively sealing the internal electrode tab weld (231) on the inner side of the internal electrode sealant layer (240) can be confirmed.

[0146] The circular shape of the internal electrode tab (230) formed by welding with the first internal current collector (210) can be confirmed inside the circular shape of the internal electrode tab welding sealant layer (232).

[0147] Finally, the innermost circle represents the internal electrode support (100).

[0148] Fig. 8 is a CC cross-sectional view of a cable-type bicell reflecting an internal member which is a conductive metal sheet according to one embodiment of the present invention.

[0149] Referring to FIG. 8, the cable-type cell includes an inner electrode (200) including a first inner electrode, an inner separation layer (800) formed spirally wound on the outside of the first inner electrode, and a second inner electrode (700) formed spirally wound on the outside of the inner separation layer (800).

[0150] The cable-type cell illustrated in FIG. 8 is configured in a bi-cell form including the first inner electrode, the inner separation layer (800), the second inner electrode (700), the outer separation layer (300), and the outer electrode (400).

[0151] Specifically, the cable-type cell illustrated in FIG. 8 may include an inner electrode support (100), a strip-shaped first inner electrode (200) formed by being spirally wound on the outside of the inner electrode support (100), a strip-shaped inner separation layer (800) formed by being spirally wound on the outside of the first inner electrode (200), a strip-shaped second inner electrode (700) formed by being spirally wound on the outside of the inner separation layer (800), an outer separation layer (300) formed by being spirally wound on the outside of the second inner electrode (700), an outer electrode (400) formed by being spirally wound on the outside of the outer separation layer (300), and an internal member (600) formed on the outside of the outer electrode (400).

[0152] The second internal electrode (700) may include a second internal current collector (720) and a second-first internal active material layer (710) and a second-second internal active material layer (730) formed on both sides of the second internal current collector (720), respectively.

[0153] The first internal electrode and the external electrode may have the same pole, and the second internal electrode may have a different pole from the first internal electrode and the external electrode.

[0154] If the first internal electrode and the external electrode are positive electrodes, the second internal electrode may be negative electrodes, and if the first internal electrode and the external electrode are negative electrodes, the second internal electrode may be positive electrodes.

[0155] The inner separation layer (800) and the outer separation layer (300) may each be an electrolyte layer or a separator.

[0156] The built-in member (600) may be in a form that wraps around both end surfaces of the cable-type cell.

[0157] When the cable-type cell is in the form of a monocell, the internal member (600) may be added to cover the external electrode (400) and a portion of the external separation layer (300) exposed at both ends of the cable-type electrode assembly.

[0158] When the above cable-type cell is in the form of the above monocell, a non-conductive internal electrode sealant layer (240) can be formed from the portion of the external separation layer (300) to which the internal member (600) is not added to the first internal active material layer (220).

[0159] At least one of the ends of both sides of the cable-type electrode assembly may have an internal electrode tab (230) formed in a portion of the first internal current collector where the built-in member and the sealant layer are not formed.

[0160] An internal electrode tab sealant layer (232) may be formed at the connection between the internal electrode tab (230) and the first internal current collector (210).

[0161] When the cable-type cell is in the bi-cell form, the internal member (600) may be added to cover the external electrode (400), the internal electrode (200), a portion of the external separation layer (300), and a portion of the internal separation layer (800) exposed at both ends of the cable-type electrode assembly.

[0162] When the cable-type cell is in the bi-cell form, a non-conductive internal electrode sealant layer (240) may be formed from a portion of the external separation layer (300) where the internal member (600) is not added to the 2-1 internal active material layer (710), and a non-conductive internal electrode sealant layer (240) may be formed from a portion of the internal separation layer (800) where the internal member (600) is not added to the 2-2 internal active material layer (730).

[0163] An internal electrode tab (230) may be formed extending from at least one end of the cable-type electrode assembly to a second internal current collector (720) on which the internal member (600) and internal electrode sealant layer (240) are not formed.

[0164] The internal electrode sealant layer (240) may include one or two or more selected from the group consisting of polypropylene, polypropylene-acrylic acid copolymer, polyethylene-acrylic acid copolymer, chlorinated polypropylene, polypropylene-butylene-ethylene terpolymer, polyethylene, polyethylene, and ethylene-propylene copolymer.

[0165] The cross-section of the above cable-shaped cell may be any one of circular, elliptical, triangular, rectangular, square, rectangular, polygonal, and amorphous shapes.

[0166] The above-mentioned built-in member can accommodate the cable-type electrode assembly in a bag-like form.

[0167] The above outer member may be formed to surround the inner member formed on both end surfaces of the cable-type cell, but may be formed to expose only a portion of the inner member.

[0168] The above outer member may be in a form that wraps around both ends of the cable-type cell, excluding the internal electrode tab.

[0169] The first inner current collector and the second inner current collector should be isolated by the inner separation layer, and the second inner current collector and the outer current collector should be isolated by the outer separation layer. The width of the inner separation layer and the outer separation layer configured in a strip shape may be larger than the width of the first inner current collector, the second inner current collector, and the outer current collector, and the length of the inner separation layer and the outer separation layer may be formed to be longer than the length of the first inner current collector, the second inner current collector, and the outer current collector.

[0170] At least one of the first inner current collector, the second inner current collector, and the outer current collector may further include a primer coating layer composed of a conductive material and a binder.

[0171] The above-mentioned conductive material may include one selected from the group consisting of carbon black, acetylene black, Ketjen black, carbon fiber, carbon nanotube, and graphene, or a mixture of two or more thereof.

[0172] The above binder is polyvinylidene fluoride (PVDF), polyvinylidene fluoride-co-hexafluoro propylene, polyvinylidene fluoride-co-trichloroethylene, polybutyl acrylate, polymethyl methacrylate, polyacrylonitrile, polyvinylpyrrolidone, polyvinylacetate, polyethylene-co-vinyl acetate, polyethylene oxide, polyarylate, cellulose acetate, cellulose acetate butyrate, cellulose acetate propionate propionate), cyanoethylpullulan, cyanoethylpolyvinylalcohol, cyanoethylcellulose, cyanoethylsucrose, pullulan, carboxyl methyl cellulose, styrene-butadiene rubber, acrylonitrile-styrene-butadiene copolymer, and polyimide. It may be any one selected from the group consisting of, or two or more of these.

[0173] At least one of the first inner current collector, the second inner current collector, and the outer current collector may be manufactured from stainless steel; aluminum; nickel; titanium; sintered carbon; copper; stainless steel surface-treated with carbon, nickel, titanium, or silver; aluminum-cadmium alloy; non-conductive polymer surface-treated with a conductive material; conductive polymer; paste including powder of Ni, Al, Au, Ag, Pd-Ag, Cr, Ta, Cu, Ba, or ITO (Indium Tin Oxide); or carbon paste including carbon powder of graphite, carbon black, or carbon nanotube.

[0174] The conductive polymer may be one selected from the group consisting of polyacetylene, polyaniline, polypyrrole, polythiophene, and polysulfonitride, or a mixture of two or more thereof.

[0175] When the first inner electrode and the outer electrode are cathodes and the second inner electrode is a cathode, the first inner active material and the outer active material may each independently include any one active material particle selected from the group consisting of natural graphite, artificial graphite, or carbonaceous material; lithium-containing titanium composite oxide (LTO); metals (Me) such as Si, Sn, Li, Zn, Mg, Cd, Ce, Ni, or Fe; alloys composed of the metals (Me); oxides (MeOx) of the metals (Me); and complexes of the metals (Me) and carbon, or mixtures of two or more thereof. When the second inner electrode is a cathode, the same as when the first inner electrode and the outer electrode are anodes can be applied.

[0176] When the first internal electrode and the external electrode are positive electrodes and the second internal electrode is negative electrodes, the first internal electrode active material and the external active material are each independently LiCoO2, LiNiO2, LiMn2O4, LiCoPO4, LiFePO4, and LiNi 1-x-y-z Co x M1 y M2 zIt may include any one active material particle selected from the group consisting of O2 (M1 and M2 are independently any one selected from the group consisting of Al, Ni, Co, Fe, Mn, V, Cr, Ti, W, Ta, Mg, and Mo, and x, y, and z are independently atomic fractions of oxide composition elements, 0 ≤ x < 0.5, 0 ≤ y < 0.5, 0 ≤ z < 0.5, 0 < x+y+z ≤ 1) or a mixture of two or more thereof. When the second internal electrode is a cathode, the same can be applied as when the first internal electrode and the external electrode are cathodes.

[0177] The inner and outer separation layers may each be an electrolyte layer or a separator.

[0178] The above separator may include a porous polymer substrate made of a polyolefin polymer selected from the group consisting of ethylene homopolymer, propylene homopolymer, ethylene-butene copolymer, ethylene-hexene copolymer, and ethylene-methacrylate copolymer; a porous polymer substrate made of a polymer selected from the group consisting of polyester, polyacetal, polyamide, polycarbonate, polyimide, polyetheretherketone, polyethersulfone, polyphenylene oxide, polyphenylene sulfide, and polyethylene naphthalate; a porous substrate formed of a mixture of inorganic particles and a binder polymer; or a porous coating layer formed of a mixture of inorganic particles and a binder polymer on at least one surface of the porous polymer substrate.

[0179] FIG. 9 is a schematic diagram of a cable-type cell of a plurality of internal electrodes, each of which reflects an internal member, which is a conductive metal sheet that serves as an electrode tab of an external electrode, according to one embodiment of the present invention.

[0180] Referring to FIG. 9, a cable-type cell includes a cable-type electrode assembly having a structure of two or more inner electrodes (200), an outer separation layer (300) and an outer electrode (400) that are formed to surround the outer surface of the inner electrode (200) and are sequentially spirally wound, and an internal member (600) that accommodates the cable-type electrode assembly. The internal member (600) may be made of a conductive material.

[0181] The internal electrode (200) may be arranged such that two or more wire-shaped internal electrodes are in contact with each other in parallel, or two or more wire-shaped internal electrodes may be arranged in a twisted form.

[0182] The above-mentioned twisted form is not limited to a specific twisted form, but can be twisted by placing multiple electrode strands side by side so that they are parallel to each other, or by twisting multiple electrode strands one by one like braiding long hair.

[0183] When there are multiple internal electrodes (200), they are densely packed together, thereby reducing the diameter of the cable-type cell according to the present invention. Such a cable-type cell can be made thinner than conventional cable-type cells, and thus can be introduced into smart fabrics or wearable applications by connecting cable-type cells in series or forming a sheet-type structure by connecting multiple cells horizontally.

[0184] By having a form in which the internal electrodes are densely packed together as described above, the internal diameter of the cable-type cell according to the present invention can be made small.

[0185] However, if the internal electrode has a hollow structure, the electrolyte can be injected through a needle, but if the internal electrode has a densely packed structure without a hollow structure as described above, it is not easy to inject the electrolyte using a needle as in the above method. Therefore, the present invention studied a method for solving the electrolyte injection problem when the internal electrode is not hollow, especially when non-hollow internal electrodes are densely packed together. To this end, the inventors devised a method of encapsulating the electrode assembly by passing the electrode assembly through an electrolyte bath so that the electrolyte is absorbed into the inside of the battery, and then performing a polymer coating to prevent the electrolyte from escaping to the outside after impregnation in the electrolyte bath.

[0186] At this time, the polymer electrolyte layer used for encapsulation absorbs electrolyte like a polymer electrolyte and has ionic conductivity.

[0187] A cable-type secondary battery manufactured through this method can facilitate electrolyte injection in a cable-type secondary battery having a densely packed, non-hollow internal electrode.

[0188] (Comparative Example 1)

[0189] A cable-type cell (Pristine cable cell) was manufactured by applying a laminate sheet having a multilayer structure as a battery case of a conventional pouch-type battery cell as an internal member covering the outer surface of a cable-type electrode assembly. The resistance between the external electrode and the external electrode tab of the cable-type cell was measured. In the experiment, the external electrode constituted the positive electrode.

[0190] (Example 1)

[0191] According to the present invention, a cable-type cell (Tabless cable cell) was manufactured by adding an internal member made of a conductive metal single-layer structure to surround the outer surface of a cable-type electrode assembly. The resistance between the external electrode and the external electrode tab of the cable-type cell was measured. In the experiment, the external electrode constituted the anode. In this Example 1, the external electrode tab functions as an internal member made of a metal single-layer structure.

[0192] Figure 10 is a graph showing the resistance between the external electrode and the external electrode tab according to the length of a conventional cable-type cell and a cable-type cell of the present invention in which the internal member is a metal layer.

[0193] In the graph of Fig. 10, the conventional cable-type cell is indicated as a Pristine cable cell, and the cable-type cell in which the internal member of the present invention is a metal layer is indicated as a Tabless cable cell.

[0194] Looking at Figure 10, in the case of a cable-type cell (Pristine cable cell) including an internal member formed of a multilayer structure of Comparative Example 1, it can be confirmed that the resistance between the positive electrode and the positive electrode tab increases rapidly at 300 mm as the length of the cable-type cell increases.

[0195] In the case of a cable-type cell (Tabless cable cell) including an internal member made of a metal single-layer structure of the present invention of Example 1, it can be confirmed that the resistance between the positive electrode and the positive electrode tab is measured to be 12.5 mOhm or less even when the length of the cable-type cell is 500 mm as the length of the cable-type cell increases.

[0196] Anyone with ordinary knowledge in the field to which the present invention pertains will be able to perform various applications and modifications within the scope of the present invention based on the above contents.

[0197] (Explanation of symbols)

[0198] 100: Internal electrode support

[0199] 200: Internal electrode

[0200] 210: First internal collector

[0201] 220: First internal activation material layer

[0202] 230: Internal electrode tab

[0203] 231: Internal electrode tab welding part

[0204] 232: Internal electrode tab sealant layer

[0205] 240: Internal electrode sealant layer

[0206] 300: External separation layer

[0207] 400: External electrode

[0208] 410: External collector

[0209] 420: External active material layer

[0210] 430: External electrode tab

[0211] 440: Polymer support layer

[0212] 500: Cable-type electrode assembly

[0213] 600: Internal parts

[0214] 610: First interior member layer

[0215] 620: Second internal member layer

[0216] 630: Third internal member layer

[0217] 640: 4th internal member layer

[0218] 700: Second internal electrode

[0219] 710: 2-1 Internal activation material layer

[0220] 720: Second inner collector

[0221] 730: 2nd-2nd internal activation material layer

[0222] 800: Inner separation layer

[0223] 900: Terminal connection line

Claims

1. A cable-type electrode assembly having an internal electrode support, one or more internal electrodes sequentially spirally wound around the internal electrode support, an external separation layer, and an external electrode structure, and Including an internal member that accommodates the above cable-type electrode assembly, The above-mentioned internal member is a cable-type cell composed of a conductive material.

2. In paragraph 1, The above-mentioned built-in member is a cable-type cell formed of a single layer or two or more laminated conductive layers.

3. In paragraph 1, The above-mentioned internal member is a cable-type cell that comes into contact with the external electrode.

4. In paragraph 1, The above-mentioned internal member is a cable-type cell that functions as an electrode tab of the above-mentioned external electrode.

5. In paragraph 1, The above internal electrode includes a first internal electrode, The first internal electrode includes a first internal current collector and a first internal active material layer formed on one surface of the first internal current collector, A cable-type cell in the form of a monocell comprising the first inner electrode, the outer separation layer, and the outer electrode.

6. In paragraph 5, The above external electrode includes an external current collector and an external active material layer formed on one surface of the external current collector, A cable-type cell in the form of a monocell comprising the first inner electrode, the outer separation layer, and the outer electrode.

7. In paragraph 5, The inner electrode includes an inner separation layer formed spirally wound on the outside of the first inner electrode and a second inner electrode formed spirally wound on the outside of the inner separation layer. A cable-type cell in the form of a bi-cell comprising the first inner electrode, the inner separation layer, the second inner electrode, the outer separation layer, and the outer electrode.

8. In paragraph 7, The above second internal electrode is a cable-type cell including a second internal current collector and a second-first internal active material layer formed on both sides of the second internal current collector, and a second-second internal active material layer.

9. In paragraph 7, A cable-type cell in which the first internal electrode and the external electrode have the same polarity, and the second internal electrode has a different polarity from the first internal electrode and the external electrode.

10. In paragraph 7, If the first internal electrode and the external electrode are positive electrodes, the second internal electrode is negative electrode, A cable-type cell in which the first internal electrode and the external electrode are cathodes and the second internal electrode is an anode.

11. In paragraph 7, A cable-type cell in which the inner separation layer and the outer separation layer are each an electrolyte layer or a separator.

12. In paragraph 1, The above-mentioned internal member is a cable-type cell that wraps around both end surfaces of the cable-type cell.

13. In paragraph 12, When the cable-type cell is in the form of a monocell, the internal member is a cable-type cell added so as to surround the external electrodes exposed at both ends of the cable-type electrode assembly and a portion of the external separation layer.

14. In paragraph 13, A cable-type cell in which a non-conductive internal electrode sealant layer is formed from a portion of the external separation layer where the internal member is not formed to the first internal active material layer, when the cable-type cell is in the monocell form.

15. In paragraph 14, A cable-type cell in which at least one of the ends of the cable-type electrode assembly has an internal electrode tab formed in a portion of the first internal current collector where the internal member and the sealant layer are not formed.

16. In paragraph 15, A cable-type cell in which an internal electrode tab sealant layer is formed at the connection portion of the internal electrode tab and the first internal current collector.

17. In paragraph 12, In the case where the cable-type cell is in the form of a bi-cell, the built-in member is a cable-type cell added to cover the external electrode, the internal electrode, a part of the external separation layer, and a part of the internal separation layer exposed at both ends of the cable-type electrode assembly.

18. In paragraph 17, When the cable-type cell is in the bi-cell form, a non-conductive internal electrode sealant layer is formed from the portion of the external separation layer to which the internal member is not added to the second-first internal active material layer. A cable-type cell in which a non-conductive internal electrode sealant layer is formed from a portion of the internal separation layer to which the built-in member is not added to the second-second internal active material layer.

19. In paragraph 18, A cable-type cell in which an internal electrode tab is formed extending from at least one end of the cable-type electrode assembly to the second internal current collector on which the internal member and the internal electrode sealant layer are not formed.

20. In paragraph 19, A cable-type cell in which the internal electrode sealant layer comprises one or two or more selected from the group consisting of polypropylene, polypropylene-acrylic acid copolymer, polyethylene-acrylic acid copolymer, chlorinated polypropylene, polypropylene-butylene-ethylene terpolymer, polyethylene, polyethylene, and ethylene-propylene copolymer.

21. In paragraph 1, The cable-shaped cell has a cross-section in any one of a circular, oval, triangular, rectangular, square, rectangular, polygonal, and amorphous shape.

22. In paragraph 1, The above-mentioned internal member is a cable-type cell that accommodates the cable-type electrode assembly in a bag-type form.

23. In paragraph 1, A cable-type cell including an outer member formed on the outer surface of the inner member and exposing only a portion of the inner member.

24. In paragraph 23, The above outer member is a cable-shaped cell that surrounds the inner member formed at both ends of the cable-shaped cell.

25. In paragraph 24, The above outer member is a cable-type cell that wraps around both ends of the cable-type cell, excluding the internal electrode tab. 26.2 or more inner electrodes, an outer separation layer formed to surround the outer surfaces of the two or more inner electrodes and wound in a spiral shape in sequence, and a cable-type electrode assembly having an outer electrode structure, and A cable-type cell comprising an internal member that accommodates the above cable-type electrode assembly, wherein the internal member is conductive.

27. In paragraph 26, The above internal electrodes are arranged such that two or more wire-shaped internal electrodes are in contact with each other in parallel, or A cable-type cell in which two or more wire-type internal electrodes are arranged in a twisted manner.

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