Electrodeless tab cable type cell with low resistance

Abstract

Due to the linear structure of cable-type cells, when a battery cell is fabricated with electrode tabs on both ends, the increased battery length increases the distance electrons travel from the electrodes to the electrode tabs, resulting in increased battery resistance and a decrease in the electron transfer rate. To solve this problem, the present invention relates to an electrodeless cable-type cell with low resistance, in which the interior member constituting the outermost shell of the cable-type cell is composed solely of a conductive layer, thereby enabling the interior member to function as an electrode tab without the need for electrode tabs on the external electrodes. This provides the shortest path for electrons to pass from the active material layer of the electrode to the electrode tab, thereby confirming low resistance characteristics.

Description

[Technical Field]

[0001] This application claims the benefit of priority based on Korean Patent Application No. 10-2023-0095051, filed July 21, 2023, the entire contents of which are incorporated herein by reference.

[0002] The present invention relates to a low-resistance electrodeless tab cable cell. Specifically, due to the linear structure of a cable cell with electrode tabs formed on both ends, the distance electrons travel from the electrodes to the electrode tabs increases as the battery length increases, resulting in increased battery resistance and a reduced electron transfer rate. To address this issue, the present invention relates to a low-resistance electrodeless tab cable cell in which the interior member constituting the outermost shell of the cable cell is made of a conductive layer, thereby enabling the interior member to function as an electrode tab without the need for separate electrode tabs for the external electrodes. [Background technology]

[0003] 2. Description of the Related Art As the safety and capacity of rechargeable lithium secondary batteries continue to improve and increase, the number of devices using the lithium secondary batteries as an energy source is increasing.

[0004] For example, the lithium secondary battery is widely used as an energy source for wireless mobile devices or wearable devices, which are small, multi-functional products, and is also used as a medium- to large-sized battery pack for use as an energy source or energy storage system (ESS) for electric vehicles and hybrid electric vehicles, which are presented as alternatives to existing gasoline and diesel vehicles that cause air pollution.

[0005] Lithium secondary batteries are classified into cylindrical and prismatic battery cells, in which an electrode assembly is housed in a cylindrical or prismatic metal case, and pouch-type battery cells, in which an electrode assembly is housed in a pouch-type case made of an 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 flexible structure.

[0006] Various wearable computer technologies and applications using such secondary batteries as a power supply have been developed and announced. Furthermore, electronic devices such as mobile phones and notebook computers are designed to have predetermined curved surfaces for ergonomic reasons. Therefore, secondary batteries for operating such electronic devices must also be formed to have various shapes, such as predetermined curved surfaces, depending on the shape of the electronic device.

[0007] In order to match the capacity and voltage according to the specifications of such devices, a pack may be constructed by connecting many pouch batteries in parallel or in series. However, this increases the overall thickness and volume of the pouch battery, reducing the flexibility of the battery itself, and mechanical stress is applied directly to the battery components during mechanical deformation, which may damage the pouch battery and cause performance degradation.

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

[0009] FIG. 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 support 100 and an internal electrode 200 including a first internal current collector 210 and a first internal active material layer 220 wound in sequence around the internal electrode support 100.

[0011] An outer separation layer 300 may be formed on the outer side of the internal electrode 200 .

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

[0013] An interior member 600 including a first interior member layer 610, a second interior member layer 620, a third interior member layer 630, and a fourth interior member layer 640 may be formed on the outside of the external electrode 400.

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

[0015] The second interior member layer 620 may be provided with a metal layer for blocking moisture and / or oxygen.

[0016] An insulating layer for insulation may be formed on the third interior material layer 630 and / or the fourth interior material layer 640.

[0017] The adhesive layer may be formed of one 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 includes an interior member. The interior member is an insulator and is formed on the outer surface of the external current collector to protect the electrode from moisture in the air and external impact. The interior member can be made of a conventional polymer resin containing a moisture barrier layer. The moisture barrier layer can be made of aluminum, liquid crystal polymer, or other materials with excellent moisture barrier properties.

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

[0020] FIG. 2 is a perspective view of the bidirectional electrode tabs 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 the electrode tabs can be connected to external terminals.

[0022] The electrode tab protruding from the lower end of FIG. 2 may be an internal electrode tab 230 of the internal electrode.

[0023] The electrode tab protruding from the upper end of FIG. 2 may be an external electrode tab 430 of the external electrode.

[0024] An internal electrode tab 230 may extend from the internal current collector, and an external electrode tab 430 may extend from the external current collector, thereby forming a unidirectional cable cell in which the internal electrode tab and the external electrode tab protrude from one end of the cable cell.

[0025] A bidirectional cable cell may be formed in which the internal electrode tab 230 and / or the external electrode tab 430 are formed on both ends of the cable cell.

[0026] The interior member is formed in the form of a sheet including an aluminum laminate layer, and has a structure that surrounds the entire internal electrode 200, the external separation layer 300, and the external electrode 400, which are wound in sequence around the internal electrode support body.

[0027] Therefore, the electrode tabs of the internal electrode 200 and the external electrode 400 have a strip shape and are welded to both ends of the cable-type cell separately from the current collectors of the internal electrode 200 and the external electrode 400 .

[0028] Due to the linear structure of such cable-type cells, electrode tabs can only be formed on both ends of the battery. As the length of the battery increases, the distance that electrons travel from the electrode to the electrode tab increases, which increases battery resistance and reduces rate characteristics related to electron mobility.

[0029] Furthermore, in the case of a unidirectional cable type cell, the internal electrode tab and the external electrode tab are formed adjacent to each other, which can cause a short circuit due to contact between the two electrode tabs.

[0030] Therefore, a cable-type cell uses a tabless structure in which an electrically conductive material that acts as a positive electrode tab is applied to the outermost packaging of the cable-type cell, aiming to provide the shortest path for electrons to pass from the active material layer of the electrode to the electrode tab. This minimizes the resistance of the cable-type cell regardless of the length of the linear battery, thereby maintaining a balance between the battery length and the deterioration of electron transport characteristics.

[0031] Korean Patent Publication No. 10-2259381 discloses a flexible secondary battery including an electrode support, a sheet-shaped internal electrode spirally wound around the electrode support, a sheet-shaped first solid electrolyte layer spirally wound around the internal electrode, a sheet-shaped bipolar electrode spirally wound around the first solid electrolyte layer, a sheet-shaped second solid electrolyte layer spirally wound around the bipolar electrode, and a sheet-shaped external electrode spirally wound around the second solid electrolyte layer, wherein the first and second solid electrolyte layers include organic solid electrolytes, and the internal and external electrodes have insulating coating portions at both longitudinal ends of one side surface facing the first and second solid electrolyte layers, respectively, and the bipolar electrode has insulating coating portions at both longitudinal ends of both sides.

[0032] However, the technology of the cable-type cell of the present invention has not been applied to a cable-type cell that uses a structure in which an interior member exposes the external electrodes in order to use the outermost shell of the cable-type cell as an electrode tab of the external electrodes.

[0033] Korean Patent Registration No. 10-2128094 discloses a cable-type secondary battery including a cable-type electrode assembly including an internal electrode, a separation layer formed to surround the outer surface of the internal electrode and prevent short-circuiting of the electrodes, and an external electrode formed to surround the separation layer, and sheet-like packaging wound spirally around the outer surface of the cable-type electrode assembly.

[0034] However, there has been no disclosure of the technology of the cable-type cell of the present invention, in which an interior member that exposes the external electrodes is formed.

[0035] Japanese Patent Application Laid-Open Publication No. 2016-066520 discloses an electricity storage device in which an electricity storage sheet composed of a positive electrode portion, a separator membrane, and a negative electrode portion is spirally wound around a wire structure, gaps are formed between the wound electricity storage sheets, and exposed portions are formed on the positive and / or negative electrode sheets of the electricity storage sheet, which are exposed to the outside of the electricity storage sheet and used as terminals.

[0036] However, there has been no disclosure of the technology of the cable-type cell of the present invention, in which an interior member that exposes the external electrodes is formed.

[0037] Japanese Patent Publication No. 2021-026957 discloses a negative electrode having a fiber bundle of bundled carbon fibers and a metal wire inserted into the fiber bundle along the longitudinal direction of the fiber bundle, and a pin-type secondary battery using the same.

[0038] However, the technology of a cable-type cell using an interior member that is wound up at intervals in order to use the outermost periphery of the cable-type cell of the present invention as an electrode tab of an external electrode has never been applied.

[0039] Therefore, due to the linear structure of cable-type cells, when a battery cell is fabricated using both ends with electrode tabs, the distance that electrons travel from the electrodes to the electrode tabs increases as the battery length increases. To solve the problem of electron transfer speed due to increased battery resistance, there is a need to develop a low-resistance electrodeless cable-type cell that removes the non-conductive material from the interior member that forms the outermost shell of the cable-type cell and forms the outermost shell of the cable-type cell with a conductive layer, thereby enabling the interior member to function as the electrode tab without the need to form electrode tabs on the external electrodes. Summary of the Invention [Problem to be solved by the invention]

[0040] The present invention has been made to solve the above-mentioned problems. When manufacturing a cable-type cell with electrode tabs formed on both ends, the distance that electrons travel from the electrodes to the electrode tabs increases as the battery length increases due to the linear structure of the cable-type cell, which results in an increase in battery resistance and a decrease in electron transfer rate. To solve this problem, the present invention provides an electrodeless cable-type cell with low resistance, in which the non-conductive material of the interior member that forms the outermost shell of the cable-type cell is removed and the outermost shell of the cable-type cell is formed with a conductive layer, thereby allowing the interior member to function as the electrode tab without the need for electrode tabs on the external electrodes.

[0041] In addition, since the pouch-type inner member, which is the outermost packaging of the cable-type cell, is conductive, the cable-type tabless structure, which serves as the electrode tab of the external electrode, is used to provide the shortest path for electrons to move from the active material layer of the electrode to the electrode tab.

[0042] Another object of the present invention is to provide a cable-type cell including a cable-type tabless structure that can extend the length of the battery without any restrictions, in order to solve the problem of the deterioration of electron mobility characteristics as the length of existing cable-type cells increases. [Means for solving the problem]

[0043] To achieve this object, a cable-type cell of an electrodeless tab having low resistance according to the present invention includes an internal electrode support, a cable-type electrode assembly having a structure in which one or more internal electrodes, an external separation layer, and an external electrode are spirally wound around the internal electrode support in that order, and an interior member that houses the cable-type electrode assembly, and the interior member may be made of a conductive material.

[0044] The interior member may be formed of a single layer or two or more laminated conductive layers.

[0045] The interior member may be in contact with the external electrode.

[0046] The interior member can function as an electrode tab for the external electrode.

[0047] The internal electrode may include a first internal electrode, the first internal electrode including a first internal current collector and a first internal active material layer formed on one surface of the first internal current collector, and may have a mono-cell configuration including the first internal electrode, the external separation layer, and the external electrode.

[0048] The 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 have a mono-cell configuration including the first internal electrode, the external separation layer, and the external electrode.

[0049] The internal electrode may include an internal separation layer spirally wound around the first internal electrode and a second internal electrode spirally wound around the internal separation layer, and may have a bi-cell shape including the first internal electrode, the internal separation layer, the second internal electrode, the external separation layer, and the external electrode.

[0050] The second internal electrode may include a second internal current collector, and a second-first internal active material layer and a second-second internal active material layer formed on both surfaces of the second internal current collector, respectively.

[0051] The first internal electrode and the external electrode may have the same polarity, and the second internal electrode may have a polarity different from that of the first internal electrode and the external electrode.

[0052] If the first internal electrode and the external electrode are positive, the second internal electrode may be negative, and if the first internal electrode and the external electrode are negative, the second internal electrode may be positive.

[0053] Each of the inner and outer separation layers may be an electrolyte layer or a separator.

[0054] The interior member may have a shape that surrounds both end surfaces of the cable-type cell.

[0055] When the cable-type cell is a mono-cell, the interior member may be provided to surround the external electrodes exposed at both ends of the cable-type electrode assembly and a portion of the external separator layer.

[0056] When the cable-type cell has the mono-cell configuration, a non-conductive internal electrode sealant layer may be formed from a portion of the external separator where the internal member is not formed to the first internal active material layer.

[0057] 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 interior member and the sealant layer are not formed.

[0058] An internal electrode tab sealant layer may be formed at a connection portion between the internal electrode tab and the first internal current collector.

[0059] When the cable-type cell is a bi-cell, the interior member may be provided to surround the external electrode, the internal electrode, a portion of the external separation layer, and a portion of the internal separation layer exposed at both ends of the cable-type electrode assembly.

[0060] 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 where the internal material is not provided 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 where the internal material is not provided to the 2-2 internal active material layer.

[0061] At least one of both ends of the cable-type electrode assembly may have an internal electrode tab extending from the second internal current collector where the interior member and the internal electrode sealant layer are not formed.

[0062] The internal electrode sealant layer may include one or more selected from the group consisting of polypropylene, polypropylene-acrylic acid copolymer, polyethylene-acrylic acid copolymer, chlorinated polypropylene, polypropylene-butylene-ethylene terpolymer, polyethylene, and ethylene-propylene copolymer.

[0063] The cross section of the cable-type cell may have any one of a circular, elliptical, triangular, quadrangular, square, rectangular, polygonal, and amorphous shape.

[0064] The interior member may house the cable-type electrode assembly in a sealed manner.

[0065] The interior member may include an exterior member formed on an outer surface of the interior member, exposing only a portion of the interior member.

[0066] The exterior member may surround the interior members formed on both ends of the cable-type cell.

[0067] The exterior member may surround both ends of the cable-type cell except for the internal electrode tabs.

[0068] To achieve this object, a cable-type cell of an electrodeless tab having low resistance according to the present invention includes a cable-type electrode assembly having a structure of two or more internal electrodes, an external separation layer formed to surround outer surfaces of the two or more internal electrodes and spirally wound in that order, and an external electrode; and an interior member that houses the cable-type electrode assembly, and the interior member may be conductive.

[0069] The internal electrodes may be arranged such that two or more wire-type internal electrodes are in contact with each other in parallel, or may be arranged such that two or more wire-type internal electrodes are twisted together.

[0070] Furthermore, the present invention can also be provided in the form of various combinations of means for solving the above problems. [Effects of the Invention]

[0071] As described above, the low-resistance electrodeless tab cable cell according to the present invention can realize low-resistance characteristics by providing the shortest path for electrons to pass from the active material layer of the electrode to the electrode tab.

[0072] 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 transport characteristics even when the battery length increases.

[0073] In addition, since the length can be extended without any restriction on the performance of the cable-type cell in response to various length changes required according to the shape requirements of electronic devices, batteries can be manufactured to fit the shapes of various electronic devices. [Brief explanation of the drawings]

[0074] [Figure 1] FIG. 1 is a cross-sectional view of a conventional cable-type cell. [Figure 2] FIG. 1 is a perspective view of a bidirectional electrode tab of a conventional cable-type cell. [Figure 3]1 is a schematic diagram of a cable-type cell to which an interior member that is a conductive metal sheet according to an embodiment of the present invention is applied. [Figure 4] 1 is a schematic diagram of an electrode tab of a cable-type cell to which an interior member, which is a conductive metal sheet that serves as an electrode tab of an external electrode, is applied according to an embodiment of the present invention; [Figure 5] 1 is an end view of a cable-type monocell to which an interior member made of a conductive metal sheet is applied according to one embodiment of the present invention. [Figure 6] 1 is a perspective view of an end portion of a cable-type monocell to which an interior member, which is a conductive metal sheet, according to an embodiment of the present invention is applied. [Figure 7] 1 is a cross-sectional view of a BB line of a cable-type monocell to which an interior member that is a conductive metal sheet according to an embodiment of the present invention is applied. [Figure 8] 1 is a cross-sectional view of a CC line of a cable-type bicell to which an interior member that is a conductive metal sheet according to one embodiment of the present invention is applied. [Figure 9] 1 is a schematic diagram of a cable-type cell having multiple internal electrodes to which an interior member, which is a conductive metal sheet that serves as an electrode tab for an external electrode, is applied according to an embodiment of the present invention. [Figure 10] 10 is a graph showing the resistance between the external electrode and the external electrode tab depending on the length of a conventional cable-type cell and a cable-type cell of the present invention in which the interior member is a metal layer. DETAILED DESCRIPTION OF THE INVENTION

[0075] Hereinafter, with reference to the accompanying drawings, a detailed description will be given of an embodiment of the present invention that will enable a person skilled in the art to easily carry out the present invention. However, in describing the operation principle of the preferred embodiment of the present invention in detail, detailed description of related well-known functions or configurations will be omitted if it is determined that such detailed description may unnecessarily obscure the gist of the present invention.

[0076] Throughout the drawings, the same reference numerals are used for parts having similar functions and actions. Throughout the specification, when a part is said to be connected to another part, this includes not only a direct connection but also an indirect connection via another element therebetween. Furthermore, unless otherwise specified, "including a certain element" does not mean that other elements are excluded, but that other elements may also be included.

[0077] Descriptions that limit or further embody elements are applicable to all inventions unless otherwise limited, and are not limited to descriptions of particular inventions.

[0078] Furthermore, throughout the description of the present invention and the claims, the singular includes the plural unless otherwise specified.

[0079] Throughout the description and claims, "or" includes "and" unless otherwise stated. Thus, "comprising A or B" means the three cases of including A, including B, or including both A and B.

[0080] The invention will now be explained with reference to the drawings and in conjunction with detailed embodiments.

[0081] FIG. 3 is a schematic diagram of a cable-type cell to which a conductive metal sheet-like interior member according to one embodiment of the present invention is applied.

[0082] Referring to FIG. 3, the cable-type cell includes an internal electrode support 100, a cable-type electrode assembly 500 having a structure in which one or more internal electrodes 200, an external separation layer 300, and an external electrode 400 are spirally wound around the internal electrode support 100 in that order, and an internal member 600 that houses the cable-type electrode assembly 500. The internal member 600 may be made of a conductive material.

[0083] Here, the spiral shape is expressed as a spiral or a helix in English, and refers to a shape that is twisted and turned within a certain range, and is similar to the shape of a general spring.

[0084] The internal electrodes, the separation layer, and the external electrodes may have a strip structure extending in one direction.

[0085] The interior member 600 is made of a conductive material, and may be in the form of a metal sheet containing aluminum, nickel, copper, or an alloy thereof, which has excellent electrical conductivity.

[0086] The internal electrode 200 may include a first internal electrode, which may include a first internal current collector 210 and a first internal active material layer 220 formed on the first internal current collector 210 .

[0087] The outer separating layers 300 can each be an electrolyte layer or a separator.

[0088] 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 .

[0089] A polymer layer 440 may be formed on the outer surfaces of the external electrode 400 to the external current collector 410 .

[0090] The polymer layer 440 may be an adhesive layer for bonding the outer surface of the external current collector 410 and the interior member 600 together.

[0091] The polymer layer 440 may be formed of one or more materials selected from the group consisting 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.

[0092] The polymer material of the adhesive layer is not limited as long as it can bond the exterior member and the interior member together.

[0093] The adhesive layer can be replaced with a pressure sensitive adhesive.

[0094] The cable-type electrode assembly 500 may include an interior member 600 provided to contact the opposite surface of the external current collector 410 on which the external active material layer 420 is formed.

[0095] The internal electrode support 100 may have an open structure with a space formed therein.

[0096] The internal electrode support 100 can have the form of one or more spirally wound wires, one or more spirally wound sheets, twisted wire, linear wire, hollow fiber, or mesh-type support.

[0097] The hollow fibers may be made of one or more materials selected from the group consisting of polyethylene, polypropylene, polytetrafluoroethylene, polyvinylidene fluoride, polyacrylonitrile, polyimide, polyethylene terephthalate, polyamideimide, polyesterimide, polyethersulfone, and polysulfone.

[0098] The internal electrode support 100 may include two or more wire-type internal electrode supports wound helically so as to cross each other.

[0099] In the space formed inside the internal electrode support 100, an internal electrode current collector core part, a lithium ion supply core part containing an electrolyte, or a filling core part may be formed.

[0100] The inner electrode current collector core may 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.

[0101] The lithium ion supply core may include a gel-type polymer electrolyte and a support.

[0102] The 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).

[0103] The electrolyte may include an electrolyte selected from solid electrolytes using PEO (polyethylene oxide), PPO (polypropylene oxide), PEI (polyethylene imine), PES (polyethylene sulfide), or PVAc (polyvinyl acetate).

[0104] The electrolyte may further include a lithium salt.

[0105] The lithium salts include LiCl, LiBr, LiI, LiClO4, LiBF4, LiB10 Cl 10 , LiPF6, LiCF3SO3, LiCF3CO2, LiAsF6, LiSbF6, LiAlCl4, CH3SO3Li, CF3SO3Li, (CF3SO2)2NLi, lithium chloroborane, lithium lower aliphatic carboxylate, and lithium tetraphenylborate, or a mixture of two or more thereof.

[0106] The gel-type polymer electrolyte may be polyethylene oxide (PEO), polyvinylidene fluoride (PVdF), polyvinylidene fluoride-co-hexafluoropropylene (PVdF-HFP), polymethymetacrylate (PMMA), polyacrylonitrile (PAN), or polyvinyl acetate (PVAc).

[0107] The first internal electrode includes 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 includes 400, an external current collector 410, and an external active material layer 420 formed on one surface of the external current collector 410.

[0108] The battery may further include a polymer film layer formed on at least one of the other surfaces of the first internal current collector 210 and the external current collector 410. By adding the polymer film layer, the active material layer can be supported by compensating for the thickness of the thin first internal current collector 210 and the external current collector 410. Furthermore, since a flexible polymer film layer is added, compared to increasing the thickness of the first internal current collector 210 and the external current collector 410 themselves, the first internal current collector 210 and the external current collector 410 can easily deform during the spiral winding process.

[0109] The 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 of these.

[0110] A polymer support layer 440 may be further formed on at least one surface of the first inner active material layer 220 and the outer active material layer 420 .

[0111] The polymer support layer 440 may be a porous polymer layer having a pore size of 0.01 μm to 10 μm and a porosity of 5% to 95%.

[0112] The polymer support layer 440 may include a polar linear polymer, an oxide-based linear polymer, or a mixture thereof.

[0113] FIG. 4 is a schematic diagram of an electrode tab of a cable-type cell to which an interior member, which is a conductive metal sheet that plays the role of an electrode tab of an external electrode, is applied according to one embodiment of the present invention.

[0114] 4, the interior member 600 may be formed of a single layer or a laminate type conductive layer of two or more layers. For example, it may be formed of a conductive layer having a single layer structure made of a material having interior conductivity, or it may be formed in a form in which two or more layers made of a material having conductivity are laminated.

[0115] The interior member 600 can be in contact with the external electrode 400 .

[0116] The interior member 600 can function as an electrode tab for the external electrode 400 .

[0117] In FIG. 4, an internal electrode tab welding portion 231 for connecting the internal electrode 200 to the internal electrode tab 230 is formed, and a terminal connecting wire 900 is connected to the internal electrode tab 230 .

[0118] The interior member 600 made of the conductive layer can function as the conventional external electrode tab 430 .

[0119] That is, by forming the interior member 600 that functions as the external electrode tab 430 of the external electrode 400, electrode terminals can be connected to the outer surface of the cable-type cell in the longitudinal direction and both ends of the cable-type cell.

[0120] The internal electrode 200 having the opposite polarity to the external electrode 400 may be connected to an electrode terminal by an internal electrode tab 230 extending from the first internal current collector 210 via an internal electrode tab welding portion 231 .

[0121] FIG. 5 is a cross-sectional view of a cable-type monocell to which an interior member that is a conductive metal sheet according to one embodiment of the present invention is applied, FIG. 6 is a perspective view of an end of a cable-type monocell to which an interior member that is a conductive metal sheet according to one embodiment of the present invention is applied, and FIG. 7 is a cross-sectional view of line BB of a cable-type monocell to which an interior member that is a conductive metal sheet according to one embodiment of the present invention is applied.

[0122] 5 to 7, if the interior member 600, which functions as the external electrode tab of the external electrode 400 and is made of a conductive sheet, 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.

[0123] The internal electrode 200 includes a first internal electrode, which includes 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 may have a mono-cell configuration including the first internal electrode, an external separation layer 300, and an external electrode 400.

[0124] 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 may have a mono-cell configuration including the first internal electrode, the external separation layer 300, and the external electrode 400.

[0125] 5, which is a cross-sectional view of one end of the mono-cell type cable cell, an internal electrode support 100 is located at the center, and from the outside around the internal electrode support 100, there are provided a first internal current collector 210, a first internal active material layer 220, an external separator 300, an external active material layer 420, an external current collector 410, and a conductive interior member 600 formed to contact the external current collector 410.

[0126] Looking at the end face of the monocell, the conductive interior member 600 may be formed to surround the outer current collector 410, the outer active material layer 420, and even a portion of the outer separator layer 300 having a predetermined thickness.

[0127] In order to prevent the interior member 600 and the internal electrode 200 from coming into contact with each other and causing a short circuit, an internal electrode sealant layer 240 may be formed from the portion of the end of the external separation layer 300 where the interior member 600 is not provided to the first internal active material layer 220.

[0128] Since the internal electrode tab 230 is formed by being welded to the first internal current collector 210, an internal electrode tab welding part 231 that connects the end of the first internal current collector 210 and the internal electrode tab 230 may be formed.

[0129] An inner electrode tab sealant layer 232 may be formed to non-conductively seal the inner electrode tab weld 231 .

[0130] In addition, a sealant layer for insulation may be further formed on the end of the interior member 600.

[0131] Referring to FIG. 5, it can be seen that the conductive interior member 600 is provided to surround the outer current collector 410, the outer active material layer 420, and even a portion of the outer separator layer 300 having a predetermined thickness.

[0132] Referring to the circular cross-sectional view perpendicular to the longitudinal direction of the cable-type cell shown in the upper part of FIG. 5, the outermost interior member 600 is shown as the largest diameter, and is provided to surround the outer current collector 410, the outer active material layer 420, and a portion of the outer separator 300 having a predetermined thickness.

[0133] The interior member 600 extends to a portion of the internal electrode tab 230, and considering the thickness of the interior member itself, the area between the first and second circles from the outside and the area between the second and third circles from the outside in the circular cross section represent the interior member 600.

[0134] The member located inside the interior 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 provided from the portion at the end of the external separation layer 300 where the interior member 600 is not provided to the first internal active material layer 220.

[0135] A circular shape of the internal electrode tab sealant layer 232 for non-conductively sealing the internal electrode tab welded portion 231 can be seen inside the internal electrode sealant layer 240 .

[0136] Inside the circle of the internal electrode tab sealant layer 232, the circle of the internal electrode tab 230 formed by welding to the first internal current collector 210 can be seen.

[0137] Finally, the innermost circle represents the internal electrode support 100 .

[0138] FIG. 8 is a cross-sectional view of a CC line of a cable-type bi-cell to which an interior member made of a conductive metal sheet according to one embodiment of the present invention is applied.

[0139] Referring to FIG. 8, the internal electrode 200 of the cable-type cell includes a first internal electrode, an internal separation layer 800 spirally wound around the outside of the first internal electrode, and a second internal electrode 700 spirally wound around the outside of the internal separation layer 800.

[0140] The cable-type cell shown in FIG. 8 is configured in a bi-cell form including the first internal electrode, the internal separation layer 800, the second internal electrode 700, the external separation layer 300 and the external electrode 400.

[0141] Specifically, the cable-type cell shown in FIG. 8 includes an internal electrode support 100, a strip-type first internal electrode 200 spirally wound around the outside of the internal electrode support 100, a strip-type internal separation layer 800 spirally wound around the outside of the first internal electrode 200, a strip-type second internal electrode 700 spirally wound around the outside of the internal separation layer 800, an external separation layer 300 spirally wound around the outside of the second internal electrode 700, an external electrode 400 spirally wound around the outside of the external separation layer 300, and an interior member 600 formed around the outside of the external electrode 400.

[0142] 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.

[0143] The first internal electrode and the external electrode may have the same polarity, and the second internal electrode may have a polarity different from that of the first internal electrode and the external electrode.

[0144] If the first internal electrode and the external electrode are positive, the second internal electrode may be negative, and if the first internal electrode and the external electrode are negative, the second internal electrode may be positive.

[0145] Each of the inner and outer separation layers 800 and 300 can be an electrolyte layer or a separator.

[0146] The interior member 600 may have a shape that surrounds both end surfaces of the cable-type cell.

[0147] When the cable-type cell is the mono-cell type, the interior member 600 may be provided to surround the external electrode 400 and a part of the external separator 300 exposed at both ends of the cable-type electrode assembly.

[0148] When the cable-type cell is a mono-cell, a non-conductive internal electrode sealant layer 240 may be formed from a portion of the external separator 300 where the internal member 600 is not provided to the first internal active material layer 220 .

[0149] At least one of both ends 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 interior member and the sealant layer are not formed.

[0150] An internal electrode tab sealant layer 232 may be formed at a connection portion between the internal electrode tab 230 and the first internal current collector 210 .

[0151] When the cable-type cell is in the bi-cell form, the interior member 600 may be provided to surround 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.

[0152] When the cable-type cell is in the bi-cell form, the non-conductive internal electrode sealant layer 240 may be formed from a portion of the outer separator 300 where the inner material 600 is not provided to the 2-1 inner active material layer 710, and the non-conductive internal electrode sealant layer 240 may be formed from a portion of the inner separator 800 where the inner material 600 is not provided to the 2-2 inner active material layer 730.

[0153] An internal electrode tab 230 may be extended from at least one of both ends of the cable-type electrode assembly to the second internal current collector 720 on which the internal member 600 and the internal electrode sealant layer 240 are not formed.

[0154] The internal electrode sealant layer 240 may include one or more selected from the group consisting of polypropylene, polypropylene-acrylic acid copolymer, polyethylene-acrylic acid copolymer, chlorinated polypropylene, polypropylene-butylene-ethylene terpolymer, polyethylene, and ethylene-propylene copolymer.

[0155] The cross section of the cable-type cell may have any one of a circular, elliptical, triangular, quadrangular, square, rectangular, polygonal, and amorphous shape.

[0156] The interior member may house the cable-type electrode assembly in a sealed manner.

[0157] The exterior member may have a configuration that surrounds the interior member formed on both end surfaces of the cable-type cell and exposes only a portion of the interior member.

[0158] The exterior member may have a shape surrounding both ends of the cable-type cell except for the internal electrode tabs.

[0159] The first internal current collector and the second internal current collector must be separated by the internal separation layer, and the second internal current collector and the external current collector must be separated by the external separation layer. Therefore, the width of the internal separation layer and the external separation layer configured in a strip shape may be greater than the widths of the first internal current collector, the second internal current collector, and the external current collector, and the length of the internal separation layer and the external separation layer may be greater than the lengths of the first internal current collector, the second internal current collector, and the external current collector.

[0160] 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.

[0161] The conductive material may include any 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 of these.

[0162] The binder may be polyvinylidene fluoride (PVDF), polyvinylidene fluoride-co-hexafluoropropylene, polyvinylidene fluoride-co-trichloroethylene, polybutyl acrylate, polymethyl methacrylate, polyacrylonitrile, polyvinylpyrrolidone, polyvinyl acetate, ethylene-co-vinylacetate, polyethylene oxide, polyarylate, cellulose acetate, cellulose acetate butyrate, or cellulose acetate propionate. The polymer may be any one or two or more selected from the group consisting of styrene-butadiene rubber, acrylonitrile-styrene-butadiene copolymer, styrene-butadiene copolymer, styrene-butadiene rubber, styrene-butadiene copolymer, styrene-butadiene copolymer, styrene-butadiene rubber, styrene-butadiene copolymer, styrene-butadiene copolymer, styrene-butadiene copolymer, styrene-butadiene copolymer, styrene-butadiene copolymer, styrene-butadiene copolymer, styrene-butadiene copolymer, styrene-butadiene copolymer, cyanoethyl cellulose ...

[0163] At least one of the first internal current collector, the second internal current collector, and the external current collector may be made of stainless steel; aluminum; nickel; titanium; calcined carbon; copper; stainless steel surface-treated with carbon, nickel, titanium, or silver; an aluminum-cadmium alloy; a non-conductive polymer surface-treated with a conductive material; a conductive polymer; a paste containing powder of Ni, Al, Au, Ag, Pd-Ag, Cr, Ta, Cu, Ba, or ITO (indum tin oxide); or a carbon paste containing carbon powder of graphite, carbon black, or carbon nanotubes.

[0164] The conductive polymer may be any one selected from the group consisting of polyacetylene, polyaniline, polypyrrole, polythiophene, and polysulfonitride, or a mixture of two or more of these.

[0165] When the first internal electrode and external electrode are negative electrodes and the second internal electrode is positive electrodes, the first internal electrode active material and external active material may each independently comprise 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) of Si, Sn, Li, Zn, Mg, Cd, Ce, Ni, or Fe; alloys composed of the metals (Me); oxides (MeOx) of the metals (Me); and composites of the metals (Me) and carbon, or a mixture of two or more of these. When the second internal electrode is positive electrodes, the same as in the case of the first internal electrode and external electrode being positive electrodes described below may be applied.

[0166] When the first internal electrode and the external electrode are positive electrodes and the second internal electrode is negative electrodes, the first internal active material and the external active material are, respectively and independently, LiCoO2, LiNiO2, LiMn2O4, LiCoPO4, LiFePO4, and LiNi 1-x-y-z Co x M1 y M2 zO2 (where M1 and M2 are each independently 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 each independently the atomic fraction of the oxide composition elements, 0 ≦ x < 0.5, 0 ≦ y < 0.5, 0 ≦ z < 0.5, and 0 < x + y + z ≦ 1). It can contain any one kind of active material particles selected from the group consisting of these or a mixture of two or more of them. When the second internal electrode is the negative electrode, it can be applied in the same manner as when the first internal electrode and the external electrode are the negative electrodes.

[0167] Each of the inner separation layer and the outer separation layer can be an electrolyte layer or a separator.

[0168] The separator can be a porous polymer substrate made of a polyolefin-based 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, polyether ether ketone, polyether sulfone, 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.

[0169] FIG. 9 is a schematic diagram of a cable-type cell of a plurality of internal electrodes to which an interior member, which is a conductive metal sheet serving as an electrode tab of an external electrode according to an embodiment of the present invention, is applied.

[0170] Referring to FIG. 9, the cable-type cell includes a cable-type electrode assembly having a structure of two or more internal electrodes 200, an external separation layer 300 formed to surround the outer surfaces of the two or more internal electrodes 200 and wound spirally in order, and an external electrode 400, and an interior member 600 that houses the cable-type electrode assembly, and the interior member 600 may be made of a conductive material.

[0171] The internal electrodes 200 may be arranged such that two or more wire-type internal electrodes are in contact with each other in parallel, or may be arranged such that two or more wire-type internal electrodes are twisted together.

[0172] The twisted configuration is not limited to a specific twisted configuration, but may be a configuration in which multiple electrodes are arranged parallel to each other and then twisted together, or multiple electrodes are offset from each other and twisted like tying hair.

[0173] When there are multiple internal electrodes 200, the internal electrodes 200 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 thinner than a conventional cable-type cell, and therefore can be introduced into smart fabric or wearable applications by connecting a long cable-type cell in series or connecting multiple cells horizontally to form a sheet-like structure.

[0174] As described above, since the internal electrodes are densely packed with each other, the inner diameter of the cable-type cell according to the present invention can be reduced.

[0175] Here, if the internal electrode has a hollow structure, electrolyte can be injected through a needle. However, if the internal electrodes are tightly packed without a hollow, as described above, it is not easy to inject electrolyte using a needle as in the previous method. Therefore, the present inventors have researched a solution to electrolyte injection when the internal electrodes are not hollow, especially when solid internal electrodes are tightly packed. To this end, the inventors have devised a method in which the electrode assembly is passed through an electrolyte bath to absorb the electrolyte into the battery, and after impregnating the electrode assembly in the electrolyte bath, a polymer coating is applied to encapsulate the electrode assembly to prevent the electrolyte from leaking out.

[0176] Here, the polymer electrolyte layer used for encapsulation absorbs an electrolytic solution like a polymer electrolyte and has ion conductivity.

[0177] The cable-type secondary battery manufactured by this method has non-hollow, densely packed internal electrodes, and can easily be filled with an electrolyte.

[0178] (Comparative Example 1) A pristine cable cell was fabricated by using a laminate sheet with a multilayer structure, which is the battery case of a conventional pouch-type battery cell, as an interior member surrounding 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.

[0179] Example 1 According to the present invention, a cable-type cell was fabricated by providing an interior member having a conductive single metal layer structure surrounding 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. In this Example 1, the function of the external electrode tab was performed by the interior member having a single metal layer structure.

[0180] FIG. 10 is a graph showing the resistance between the external electrode and the external electrode tab depending on the length of a conventional cable-type cell and a cable-type cell of the present invention in which the interior member is a metal layer.

[0181] In the graph of FIG. 10, the conventional cable-type cell is represented by a pristine cable cell, and the cable-type cell of the present invention in which the interior member is a metal layer is represented by a tabless cable cell.

[0182] Referring to FIG. 10, in the case of a pristine cable cell including an inner member having a multilayer structure according to Comparative Example 1, it can be seen that as the length of the cable cell increases, the resistance between the positive electrode and the positive electrode tab increases sharply at a length of 300 mm.

[0183] In the case of a cable-type cell including an interior member having a single metal layer structure according to the present invention in Example 1, it can be seen that the resistance between the positive electrode and the positive electrode tab is measured to be 12.5 mOhm or less even in the case of a cable-type cell having a length of 500 mm, as the length of the cable-type cell increases.

[0184] Those skilled in the art will be able to make various applications and modifications within the scope of the present invention based on the above content. [Explanation of symbols]

[0185] 100 Internal electrode support 200 Internal electrode 210 First inner current collector 220 First inner active material layer 230 Internal electrode tab 231 Internal electrode tab weld 232 Internal electrode tab sealant layer 240 Internal electrode sealant layer 300 outer separation layer 400 external electrode 410 External current collector 420 Outer active material layer 430 External electrode tab 440 Polymer layer 500 Cable-type electrode assembly 600 Interior materials 610 1st interior material layer 620 2nd interior material layer 630 3rd interior material layer 640 4th interior material layer 700 2nd internal electrode 710 2nd-1 internal active material layer 720 Second internal current collector 730 2nd-2nd internal active material layer 800 internal separation layer 900 Terminal Connection Wire

Claims

1. a cable-type electrode assembly having an internal electrode support, and one or more internal electrodes, an external separation layer, and an external electrode wound spirally around the internal electrode support in this order; an interior member that houses the cable-type electrode assembly, The interior member is made of a conductive material.

2. 2. The cable-type cell according to claim 1, wherein the interior member is formed of a single layer or two or more laminated conductive layers.

3. The cable-type cell according to claim 1 , wherein the interior member is in contact with the external electrode.

4. The cable-type cell according to any one of claims 1 to 3, wherein the interior member functions as an electrode tab for the external electrode.

5. the internal electrodes include 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; The cable-type cell according to any one of claims 1 to 3, in the form of a mono-cell, comprising the first internal electrode, the external separation layer, and the external electrode.

6. The external electrode includes an external current collector and an external active material layer formed on one surface of the external current collector, 6. The cabled cell of claim 5 in a mono-cell configuration, including the first internal electrode, the external separator layer, and the external electrode.

7. The internal electrode is an internal separation layer formed by being wound spirally around the outside of the first internal electrode; a second internal electrode wound spirally around the outer side of the internal separation layer, The cable-type cell according to claim 5 , in a bi-cell configuration, including the first internal electrode, the internal separation layer, the second internal electrode, the external separation layer, and the external electrode.

8. 8. The cable-type cell of claim 7, wherein the second internal electrode includes a second internal current collector, and a second-1 internal active material layer and a second-2 internal active material layer formed on both surfaces of the second internal current collector, respectively.

9. The cable-type cell according to claim 7 , wherein the first internal electrode and the external electrode have the same polarity, and the second internal electrode has a polarity different from the first internal electrode and the external electrode.

10. When the first internal electrode and the external electrode are positive electrodes, the second internal electrode is negative electrode; 8. The cable-type cell according to claim 7, wherein when the first internal electrode and the external electrode are negative electrodes, the second internal electrode is positive.

11. 8. The cable-type cell according to claim 7, wherein each of the inner and outer separation layers is an electrolyte layer or a separator.

12. The cable-type cell according to any one of claims 1 to 3, wherein the interior member surrounds both end faces of the cable-type cell.

13. The cable-type cell according to claim 12, wherein when the cable-type cell is a mono-cell, the interior member is provided to surround the external electrodes and portions of the external separator layer exposed at both ends of the cable-type electrode assembly.

14. 14. The cable-type cell according to claim 13, wherein, when the cable-type cell is in the mono-cell form, a non-conductive internal electrode sealant layer is formed from a portion of the external separator where the interior member is not formed to the first internal active material layer.

15. 15. The cable-type cell according to claim 14, wherein at least one of both ends of the cable-type electrode assembly has an internal electrode tab formed in a portion of the first internal current collector where the interior member and the sealant layer are not formed.

16. The cable type cell according to claim 15 , wherein an internal electrode tab sealant layer is formed at a connection portion between the internal electrode tab and the first internal current collector.

17. 13. The cable-type cell according to claim 12, wherein when the cable-type cell is a bi-cell, the interior member is provided to surround the external electrode, the internal electrode, a portion of the external separator layer, and a portion of the internal separator layer exposed at both ends of the cable-type electrode assembly.

18. When the cable-type cell is in the bi-cell form, a non-conductive internal electrode sealant layer is formed from a portion of the external separation layer where the internal member is not provided to the second-first internal active material layer, The cable-type cell according to claim 17, wherein a non-conductive internal electrode sealant layer is formed from a portion of the internal separation layer where the interior member is not provided to the second-second internal active material layer.

19. 20. The cable-type cell according to claim 18, wherein at least one of both ends of the cable-type electrode assembly has an internal electrode tab extending from the second internal current collector on which the interior member and the internal electrode sealant layer are not formed.

20. 20. The cable-type cell according to claim 19, wherein the internal electrode sealant layer comprises one or more selected from the group consisting of polypropylene, polypropylene-acrylic acid copolymer, polyethylene-acrylic acid copolymer, chlorinated polypropylene, polypropylene-butylene-ethylene terpolymer, polyethylene, and ethylene-propylene copolymer.

21. The cable-type cell according to any one of claims 1 to 3, wherein the cross section of the cable-type cell has any one of a circular, elliptical, triangular, quadrangular, square, rectangular, polygonal, and amorphous shape.

22. 4. The cable-type cell according to claim 1, wherein the interior member hermetically houses the cable-type electrode assembly.

23. The cable-type cell according to any one of claims 1 to 3, further comprising an exterior member formed on an outer surface of the interior member, exposing only a portion of the interior member.

24. The cable-type cell according to claim 23 , wherein the exterior member surrounds the interior member formed on both ends of the cable-type cell.

25. 25. The cable-type cell according to claim 24, wherein the exterior member surrounds both ends of the cable-type cell except for the internal electrode tabs.

26. a cable-type electrode assembly having a structure of two or more internal electrodes, an external separation layer formed to surround outer surfaces of the two or more internal electrodes and wound spirally in order; and an interior member that houses the cable-type electrode assembly, The cable-type cell, wherein the interior member is electrically conductive.

27. The internal electrodes are two or more wire-type internal electrodes arranged in parallel and in contact with each other, or 27. The cable-type cell of claim 26, wherein two or more wire-type internal electrodes are arranged in a twisted configuration with respect to each other.

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