Curved secondary battery including electrode support, and manufacturing method thereof

Abstract

The present invention relates to a curved secondary battery including an electrode support capable of operating without shape deformation and capable of operating in a device requiring energy without damaging to a curved cell, and a manufacturing method thereof, the support being formed inside an electrode assembly in order to prevent shape deformation of the curved cell, wherein a curved cell manufactured in a curved cell production jig is produced with a rounded shape having a specific curvature, and when charging and discharging are repeated in a device where the curved cell is mounted, shape deformation may occur. The present invention has an effect of maintaining the shape of the curved secondary battery even after charging and discharging are repeated.

Description

Curved secondary battery including electrode support and manufacturing method thereof

[0001] This application claims the benefit of priority to Korean Patent Application No. 2023-0125427, filed September 20, 2023, the entire contents of which are incorporated herein by reference.

[0002] The present invention relates to a curved secondary battery including an electrode support and a method for manufacturing the same. Specifically, a curved cell manufactured in a curved cell production jig is produced in a round shape having a specific curvature, and as charging and discharging are repeated in a device in which the curved cell is mounted, the shape of the curved cell is deformed. Therefore, in order to prevent such deformation of the curved cell, a support is formed inside an electrode assembly, and the present invention relates to a curved secondary battery including an electrode support capable of operating without shape deformation and capable of operating in a device requiring energy without damage to the curved cell, and a method for manufacturing the same.

[0003]

[0004] 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.

[0005] 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).

[0006] 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 structural deformability.

[0007] Various wearable computer technologies and applications utilizing these secondary batteries as a power source are being developed and announced. Furthermore, electronic devices such as mobile phones and laptops are being designed with curved surfaces for ergonomic design. Accordingly, the secondary batteries that power these electronic devices also need to be shaped with a curved surface that matches the shape of the electronic devices.

[0008] Curved cells, formed with such a curved surface, are often subject to deformation during repeated charging and discharging when installed in energy-intensive devices. Curved cells and their manufacturing methods are required to prevent this deformation and maintain the exact thickness and curvature required for the product's specifications.

[0009] Korean Patent Publication No. 10-2015-0092669 discloses a configuration comprising a curved electrode assembly, an outer covering for sealing the electrode assembly, a reinforcing layer which is a curved plate positioned on the outer covering, an adhesive layer bonding the reinforcing layer, and a bending strength of the reinforcing layer which is greater than the volume expansion force of a curved secondary battery.

[0010] However, there is a difference from the technology of the present invention in that an internal support is applied to prevent curvature deformation by being formed on a specific surface of the electrode assembly inside the pouch.

[0011] Korean Patent Publication No. 10-2013-0119664 discloses a technology for a curved electrode assembly, a pouch for sealing the electrode assembly, a reinforcing portion formed continuously on the side of the body of the pouch, and the area, width, and constant curvature characteristics of the reinforcing portion.

[0012] However, there is a difference from the technology of applying an internal support to prevent curvature deformation by forming an electrode active material of an electrode assembly on a current collector surface inside the pouch of the present invention.

[0013] Korean Patent Publication No. 10-2003-0096718 discloses an electrode assembly comprising a positive electrode plate, a negative electrode plate, and a separator interposed between the positive and negative electrode plates, the electrode assembly comprising a pouch in which at least a portion of electrode leads connected to the positive and negative electrode plates are stored in a state in which the electrode leads are exposed to the outside; and at least one reinforcing member attached to all or part of the surface of the pouch; wherein the reinforcing member is a metal member technology.

[0014] However, there is a difference from the technology in which an internal support having elastic restoring force at high temperatures due to repeated charging and discharging of the curved cell is applied to prevent curvature deformation by being formed on a specific surface of the electrode assembly inside a pouch accommodating the curved cell of the present invention.

[0015] Japanese Patent Laid-Open No. 2002-251855 discloses a non-aqueous secondary battery having a battery element and an outer film encapsulating the battery element and having a moisture-proof layer and a synthetic resin layer, characterized in that the outer film is laminated in four or more layers by folding the outer film so that the joint portions of the outer film overlap and are pressed together, wherein the outer film is laminated in such a way that the edges of the outer film overlap and are joined together.

[0016] However, there is a difference from the technology of the present invention in that an internal support made of a thermosetting material is applied to prevent curvature deformation by being formed on a specific surface of the electrode assembly inside the pouch.

[0017] Therefore, in order to prevent curvature deformation, shape deformation, asymmetry, uneven thickness, and damage to the pouch and / or lead of the curved cell that may occur during the charge / discharge process of the curved cell, a curved secondary battery including an electrode support that can be operated without shape deformation and a manufacturing method thereof without damage to the curved cell by forming a support inside the electrode assembly is required.

[0018] (Prior art literature)

[0019] (Patent Document 1) Korean Patent Publication No. 10-2015-0092669

[0020] (Patent Document 2) Korean Patent Publication No. 10-2013-0119664

[0021] (Patent Document 3) Korean Patent Publication No. 10-2003-0096718

[0022] (Patent Document 4) Japanese Patent Publication No. 2002-251855

[0023]

[0024] The present invention is intended to solve the above-mentioned problem, and a curved cell manufactured in a curved cell production jig is produced in a round shape having a specific curvature. However, as charging and discharging are repeated in a device equipped with the curved cell, a shape deformation of the curved cell occurs. In order to prevent such shape deformation of the curved cell, a support is formed inside an electrode assembly, and an object of the present invention is to provide a curved secondary battery including an electrode support capable of operating without shape deformation and capable of operating in a device requiring energy without damage to the curved cell, and a method for manufacturing the same.

[0025]

[0026] To achieve this purpose, a curved secondary battery according to the present invention may be a curved secondary battery including an electrode assembly (100) having a curved positive electrode / separator / negative electrode stacked structure; a cell case (200) accommodating the electrode assembly therein; and an internal support (300) having a curved shape formed on at least one surface of the electrode assembly.

[0027] In addition, the electrode assembly may be a stack / folding electrode assembly in which stacked monocells, bicells, or full cells are sequentially wound as unit cells by the separator sheet.

[0028] In addition, the internal support may be formed on the collector surface (110, 120) on which the active material layer is not formed among the collectors forming the electrode.

[0029] In addition, the internal support may be formed on one or more longitudinal (y-direction) current collector side surfaces (130, 140) of the laminated electrode assembly.

[0030] In addition, the material of the internal support may be selected from one or two or more of metal, ceramic, or polymer compounds.

[0031] Additionally, the polymer compound may be a thermosetting polymer compound.

[0032] In addition, the thermosetting polymer compound may be selected from one or two or more of polyamide (PA), polyarylene ether (PPE), polyether ether ketone (PEEK), polyamideimide (PI), and polytetrafluoroethylene (PTFE).

[0033] Additionally, the internal support may be formed on a part or the entire surface of the collector or a side surface of the collector.

[0034] Additionally, the thickness of the inner support may decrease from the center of the contact member toward the side.

[0035] In addition, the internal support may have one or more support bars having elastic restoring force formed therein in the width and length directions.

[0036] The present invention can also be provided in a form in which various means for solving the above problem are combined.

[0037]

[0038] As described above, the curved secondary battery according to the present invention can maintain its shape even when charging and discharging are repeated.

[0039] In addition, the internal support having elastic restoring force can maintain the shape of the curved secondary battery even in a high-temperature environment due to charging and discharging within the electrode assembly.

[0040] Therefore, it has the effect of preventing curvature deformation by reinforcing the vulnerable parts that occur when manufacturing curved cells.

[0041]

[0042] Figure 1 is a conceptual diagram of a curved secondary battery with an existing reinforced layer formed thereon.

[0043] Figure 2 is a perspective view of a curved secondary battery having an existing reinforcement layer formed thereon.

[0044] Figure 3 is a graph showing the curvature strain rate and thickness change according to the number of charge / discharge cycles of a curved secondary battery and a curved secondary battery with a conventional reinforced layer formed thereon.

[0045] Figure 4 is a drawing showing the shape deformation of a curved secondary battery with an existing reinforced layer formed on a device.

[0046] Figure 5 is a cross-sectional view of an electrode assembly in which an internal support body is formed on a collector surface according to one embodiment of the present invention.

[0047] Figure 6 is a cross-sectional view of an electrode assembly in which an internal support body is formed on the side of a current collector according to one embodiment of the present invention.

[0048] Figure 7 is a cross-sectional view of a curved secondary battery in which an internal support body is formed on a collector surface according to one embodiment of the present invention.

[0049] Figure 8 is a cross-sectional view before disassembly of a curved secondary battery in which an internal support body is formed on a collector surface according to one embodiment of the present invention.

[0050] FIG. 9 is a cross-sectional view after disassembly of a curved secondary battery in which an internal support body is formed on a collector surface according to an embodiment of the present invention.

[0051] Figure 10 is a cross-sectional view before and after disassembly of a curved secondary battery having an internal support and an adhesive layer formed on the surface of a current collector according to an embodiment of the present invention.

[0052] FIG. 11 is a drawing of an electrode assembly including an internal support having a thickness variation according to one embodiment of the present invention.

[0053] FIG. 12 is a perspective view of an electrode assembly including an internal support including a support bar according to one embodiment of the present invention.

[0054] FIG. 13 is a cross-sectional view taken along line A-A' of an electrode assembly including an internal support including a support bar according to an embodiment of the present invention.

[0055] FIG. 14 is a cross-sectional view taken along line B-B' of an electrode assembly including an internal support including a support bar according to an embodiment of the present invention.

[0056]

[0057] 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.

[0058] 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.

[0059] 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.

[0060] Additionally, throughout the description and claims of the invention herein, the singular includes the plural unless otherwise stated.

[0061] 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.

[0062] The present invention is described in detail with examples according to the drawings.

[0063] The electrode assembly can be manufactured, for example, by stacking a positive electrode plate coated with a positive active material, a negative electrode plate coated with a negative active material, and a separator interposed between the positive electrode plate and the negative electrode plate multiple times.

[0064] The electrode assembly is a laminated body made up of a positive electrode plate, a separator, and a negative electrode plate.

[0065] It can also be manufactured by winding it into a reel shape.

[0066] The positive electrode plate may include a positive electrode active material portion coated with a positive electrode active material and a positive electrode non-conductive portion not coated with a positive electrode active material. The positive electrode active material may be a lithium-containing transition metal oxide such as LiCoO2, LiNiO2, LiMnO2, or LiMnO4, or a lithium chalcogenide compound.

[0067] The positive electrode active material portion is formed, for example, by applying the positive electrode active material to at least a portion of one side of an aluminum plate, and the remaining portion of the aluminum plate on which the positive electrode active material is not applied may become the positive electrode non-conductive portion.

[0068] The negative electrode plate may include a negative electrode active material portion coated with a negative electrode active material and a negative electrode non-coated portion not coated with a negative electrode active material. The negative electrode active material may be a carbon material such as crystalline carbon, amorphous carbon, a carbon composite, carbon fiber, lithium metal, or a lithium alloy.

[0069] The negative electrode active material portion is formed, for example, by applying a negative electrode active material to at least a portion of one side of a copper plate, and the remaining portion of the copper plate on which the negative electrode active material is not applied may become a negative electrode non-conductive portion.

[0070] The separator can be manufactured by coating a polyvinylidene fluoride-hexafluoropropylene copolymer (PVDF-HFP co-polymer) on any one substrate selected from the group consisting of, for example, polyethylene (PE), polystyrene (PS), polypropylene (PP), and copolymers of polyethylene (PE) and polypropylene (PP).

[0071] The electrode assembly is provided with a first electrode tab and a second electrode tab. Specifically, a first electrode tab and a second electrode tab (134) are provided with a first electrode tab and a second electrode tab (134) respectively, and the first electrode tab and the second electrode tab can be extended to the outside by penetrating the pouch.

[0072] The pouch seals the electrode assembly and contains an electrolyte together with the electrode assembly within. The pouch may, for example, be composed of a three-layer structure comprising an insulating layer, a metal layer, and an insulating layer. For example, the metal layer may be formed of aluminum, steel, stainless steel, or the like, and the insulating layer may be formed of, but is not limited to, modified polypropylene (CPP), polyethylene terephthalate (PET), nylon, or the like.

[0073] The pouch may include a pair of wings formed by fusion bonding. The pouch may include a receiving portion forming a first surface and a cover portion forming a second surface. A receiving space capable of accommodating an electrode assembly is formed in the receiving portion, and when the electrode assembly is received in the receiving space, the receiving portion and the cover portion, which are formed continuously on one side, are folded onto the receiving portion, and then the receiving portion and the cover portion are fusion bonded at an edge of the receiving space. Thereby, the electrode assembly can be sealed, and the edges where the receiving portion and the cover portion are joined form a pair of wings. The pair of wings can be bent parallel to a side surface of the curved secondary battery.

[0074] The curved cell has a curved shape with a constant radius of curvature (R) through a molding process. That is, the curved cell can have a constant curved surface depending on the shape of the electronic device to which it is mounted, thereby eliminating the gap between the electronic device and the curved cell, enabling efficient use of the internal space of the electronic device, and preventing damage to the curved cell due to movement within the electronic device (not shown).

[0075] Meanwhile, the smaller the radius of curvature (R) of the curved cell, the more pressure must be applied to the curved cell during the forming process. If the pressure increases in this way, a region where stress is concentrated may be formed in the curved cell being pressed, and deformation such as warping may occur in the curved cell. However, the present invention can minimize the stress generated in the curved cell by applying a minimum amount of pressure through two forming processes, and can manufacture a curved cell having a small radius of curvature (R) of 50R or less.

[0076] (Comparative example)

[0077] Figure 1 is a conceptual diagram of a curved secondary battery with an existing reinforced layer formed thereon.

[0078] Figure 2 is a perspective view of a curved secondary battery having an existing reinforcement layer formed thereon.

[0079] A curved secondary battery may have a curved shape with a constant radius of curvature (R). That is, the curved secondary battery has a constant curved surface depending on the shape of the electronic device into which it is mounted, thereby eliminating the space between the electronic device and the curved secondary battery, thereby enabling efficient use of the internal space of the electronic device.

[0080] The curved secondary battery of FIGS. 1 and 2 may include a pouch having an electrode assembly, a first outer covering material sealing the electrode assembly, and a second outer covering material, and a reinforcing layer attached to the first outer covering material.

[0081] Figure 3 is a graph showing the curvature strain rate and thickness change according to the number of charge / discharge cycles of a curved secondary battery and a curved secondary battery with a conventional reinforced layer formed thereon.

[0082] The change in curvature and thickness according to the number of charge / discharge cycles of a curved secondary battery with a reinforcing layer formed on the outside of an existing pouch and a curved secondary battery without any auxiliary member were measured.

[0083] Looking at Figure 3, it can be seen that in the first 100 cycles, the curvature change rate of the curved battery with the reinforcement layer formed and the curved secondary battery without the auxiliary member increase by up to 7% with almost no difference.

[0084] From 100 cycles onwards, it can be seen that the curvature change rate of the curved secondary battery with the reinforcement layer formed slightly increases by up to 10% compared to the curved secondary battery without the auxiliary member.

[0085] Therefore, it can be confirmed that the effect of reducing the curvature change rate of the curved secondary battery with the reinforcement layer formed is almost non-existent.

[0086] Looking at Figure 3, it can be seen that the change in thickness increases by up to 5% with almost no difference in the curvature change rate between the curved battery with the reinforcement layer formed and the curved secondary battery without the auxiliary member up to the first 100 cycles.

[0087] From 100 cycles onwards, it can be seen that the thickness change of the curved secondary battery with the reinforced layer formed increases slightly by up to 6% compared to the thickness change of the curved secondary battery without auxiliary members.

[0088] Therefore, it can be confirmed that the effect of reducing thickness change of the curved secondary battery with the reinforcement layer formed is almost non-existent.

[0089] Figure 4 is a drawing showing the shape deformation of a curved secondary battery with an existing reinforced layer formed on a device.

[0090] When assembling an existing curved secondary battery with a reinforced layer formed on the outside of the pouch into a device requiring energy, it can be confirmed that the curved secondary battery with the reinforced layer formed is lifted after charging and discharging.

[0091] Figure 5 is a cross-sectional view of an electrode assembly in which an internal support body is formed on a collector surface according to one embodiment of the present invention.

[0092] A curved secondary battery may be a curved secondary battery including an electrode assembly (100) having a curved positive electrode / separator / negative electrode stacked structure; a cell case (200) that accommodates the electrode assembly therein; and an internal support (300) having a curved shape formed on at least one surface of the electrode assembly.

[0093] The above electrode assembly may include a separator between the positive electrode active material forming the positive electrode and the negative electrode and the electrode plate on which the negative electrode active material is formed, preferably a current collector.

[0094] For example, the electrode assembly may be formed by sequentially stacking a positive electrode plate, a separator, and a negative electrode plate.

[0095] Alternatively, the electrode assembly may be wound together around a winding axis to have a jelly-roll structure.

[0096] Additionally, the electrode assembly may be bent in a direction perpendicular to the longitudinal direction, so that the central axis of the stack may have a curved shape. Accordingly, the electrode assembly may include a concavely curved first surface (S1) and a convexly curved second surface (S2) opposite to the first surface (S1).

[0097] In addition, the electrode assembly may be a stack / folding electrode assembly in which stacked monocells, bicells, or full cells are sequentially wound as unit cells by the separator sheet.

[0098] The basic units of electrochemical cells were monocells, full cells, or bicells.

[0099] A monocell can be configured as a double-sided electrode plate structure in which electrode active materials are applied to both sides of a current collector. Since it is a double-sided electrode plate itself, rather than a laminated structure of the monocell separator and electrode plate, it is easy to handle during the process.

[0100] As an advanced structure electrode assembly that is a hybrid of a jelly-roll type and a stack type, there may be a stack / folding type electrode assembly having a structure in which a full cell of a positive electrode / separator / cathode structure of a certain unit size or a bicell of a positive electrode (negative electrode) / separator / negative electrode (anode) / separator / anode (cathode) structure is folded using a long continuous separation film.

[0101] The characteristics of a full cell or bicell are largely determined by the electrodes, electrolyte, and other materials used. The content of active material in the electrode is ultimately related to the maximum number of lithium ions that can be combined. Therefore, higher active material content leads to higher-capacity batteries. Therefore, if the binder's adhesive strength is superior, allowing for a reduced amount of binder, electrodes with higher active material content can be manufactured. Therefore, there is a pressing need for a binder with superior adhesive strength.

[0102] Figure 6 is a cross-sectional view of an electrode assembly in which an internal support body is formed on the side of a current collector according to one embodiment of the present invention.

[0103] In addition, the internal support may be formed on the collector surface (110, 120) on which the active material layer is not formed among the collectors forming the electrode.

[0104] The above-mentioned collector surface may be the outermost electrode of an electrode assembly that is laminated in multiple layers.

[0105] The above electrode may be a cathode and / or an anode.

[0106] In addition, the internal support may be formed on one or more longitudinal (y-direction) current collector side surfaces (130, 140) of the laminated electrode assembly.

[0107] Therefore, the inner support can be in contact with the side surfaces of the plurality of stacked electrodes and separators.

[0108] The above inner support can be formed in a shape that surrounds the side surfaces of the plurality of stacked electrodes and separators.

[0109] The above internal support may be in a form that surrounds the entirety of the electrode current collector side surface and a part of the electrode current collector surface.

[0110] The above internal support may be in the shape of a “ㄷ”.

[0111] Figure 7 is a cross-sectional view of a curved secondary battery in which an internal support body is formed on a collector surface according to one embodiment of the present invention.

[0112] Figure 8 is a cross-sectional view before disassembly of a curved secondary battery in which an internal support body is formed on a collector surface according to one embodiment of the present invention.

[0113] In addition, the material of the internal support may be selected from one or two or more of metal, ceramic, or polymer compounds.

[0114] Additionally, the polymer compound may be a thermosetting polymer compound.

[0115] In addition, the thermosetting polymer compound may be selected from one or two or more of polyamide (PA), polyarylene ether (PPE), polyether ether ketone (PEEK), polyamideimide (PI), and polytetrafluoroethylene (PTFE).

[0116] Figure 9 is an exploded cross-sectional view of a curved secondary battery having an internal support formed on a current collector surface according to an embodiment of the present invention. In addition, an adhesive layer may be formed between the internal support and the current collector surface or the side surface of the current collector.

[0117] In addition, the adhesive layer may be selected from one or two or more of epoxy, silicone, polyurethane, polyamide, Teflon, and ceramic adhesives.

[0118] Figure 10 is a cross-sectional view before and after disassembly of a curved secondary battery having an internal support and an adhesive layer formed on the surface of a current collector according to an embodiment of the present invention.

[0119] Additionally, the internal support may be formed on a part or the entire surface of the collector or a side surface of the collector.

[0120] FIG. 11 is a drawing of an electrode assembly including an internal support having a thickness variation according to one embodiment of the present invention.

[0121] Additionally, the thickness of the inner support may decrease from the center of the contact member toward the side.

[0122] FIG. 12 is a drawing of an electrode assembly including an internal support including a support bar according to one embodiment of the present invention.

[0123] In addition, the internal support may have one or more support bars having elastic restoring force formed therein in the width and length directions.

[0124] It is possible to prevent damage to a curved secondary battery due to movement of the curved secondary battery inside an electronic device.

[0125] FIG. 13 is a cross-sectional view taken along line A-A' of an electrode assembly including an internal support including a support bar according to an embodiment of the present invention.

[0126] FIG. 14 is a cross-sectional view taken along line B-B' of an electrode assembly including an internal support including a support bar according to an embodiment of the present invention.

[0127] The above support bar may have a cross-sectional shape of any one of a circle, triangle, square, and “ㄱ” shape.

[0128] The above support bar may be formed one or more times inside the internal support body in contact with the surface of the current collector or the side surface of the current collector.

[0129] The above internal support may be formed with one or more support bars having different lengths and having elastic restoring force inside.

[0130] The above internal support may have one or more support bars having different thicknesses and having elastic restoring force formed therein.

[0131] The material of the above support bar may be at least one of metal, polymer, and ceramic.

[0132] The elastic restoring force of the above support bar may be greater than or equal to that of the internal support body, and the above support bar and the internal support body may be formed of the same material.

[0133] 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.

[0134] (Explanation of symbols)

[0135] 100: Curved secondary battery

[0136] 110: Electrode assembly

[0137] 120, 220: Pouch

[0138] 122: Pouch cup

[0139] 124: Pouch cover

[0140] 132: Electrode tab

[0141] 140: Reinforcement layer

[0142] 200: Device

[0143] 210: Excitation

[0144] 300: Internal support

[0145] 310: Support bar

[0146] 400: Adhesive layer

Claims

1. Electrode assembly having a curved shape of anode / separator / cathode laminated structure; A cell case that houses the electrode assembly therein; and A curved secondary battery comprising an internal support having a curved shape formed on at least one surface of the electrode assembly.

2. In paragraph 1, The above electrode assembly is a curved secondary battery that is a stack / folding electrode assembly in which stacked monocells, bicells, or full cells are sequentially wound by the separator sheet as unit cells.

3. In paragraph 1, A curved secondary battery in which the internal support is formed on the surface of the current collector forming the electrode, on which the active material layer is not formed.

4. In paragraph 1, A curved secondary battery in which the internal support is formed on at least one longitudinal (y-direction) current collector side of the stacked electrode assembly.

5. In paragraph 3, A curved secondary battery in which the material of the internal support is one or more of metal, ceramic, or polymer compound.

6. In paragraph 5, The above polymer compound is a curved secondary battery that is a thermosetting polymer compound.

7. In paragraph 6, A curved secondary battery in which the thermosetting polymer compound is selected from one or more of polyamide (PA), polyarylene ether (PPE), polyether ether ketone (PEEK), polyamideimide (PI), and polytetrafluoroethylene (PTFE).

8. In paragraph 3 or 4, A curved secondary battery in which an adhesive layer is formed between the internal support and the current collector surface or the current collector side surface.

9. In paragraph 8, A curved secondary battery in which the adhesive layer is selected from one or more of epoxy, silicone, polyurethane, polyamide, Teflon, and ceramic adhesives.

10. In paragraph 3 or 4, A curved secondary battery in which the internal support is formed on a part or the entire surface of the current collector or a side surface of the current collector.

11. In paragraph 3 or 4, A curved secondary battery in which the thickness of the inner support body decreases from the center of the contact member toward the side.

12. In paragraph 3 or 4, The above internal support is a curved secondary battery in which one or more support bars having elastic restoring force are formed in the width and length directions.

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