Cylindrical secondary battery and method for manufacturing cylindrical secondary battery

Abstract

A cylindrical secondary battery and a method of manufacturing a cylindrical secondary battery are described in which an inner surface of a can is coated to insulate an electrode assembly and the can from each other and improve heat resistance of the can. The cylindrical secondary battery may include: an electrode assembly; a can in which the electrode assembly is accommodated and one end of which is open, the can being configured to be electrically connected to the electrode assembly; a cap plate coupled to the one end of the tank; and a rivet terminal insulated from the can and the cap plate, the cap plate may be configured to seal one end of the can and may be insulated from the can. A first coating may be provided on at least a portion of an interior surface of the can.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to and the benefit of Korean Patent Application No. 10-2023-0090964 filed in the Korean Intellectual Property Office on July 13, 2023, the entire contents of which are incorporated herein by reference. Technical Field

[0003] Embodiments relate to a secondary battery. Background Art

[0004] In general, a cylindrical secondary battery may include a cylindrical electrode assembly, a cylindrical can containing the electrode assembly and an electrolyte, and a cap assembly of the can. The cap assembly may be electrically connected to the electrode assembly to electrically connect an external component to the electrode assembly. The electrode assembly may have a shape in which a negative electrode plate, a positive electrode plate, and a separator between the negative electrode plate and the positive electrode plate are wound into a cylindrical shape.

[0005] The above information provided as background for the present disclosure is only for improving understanding of the background of the present disclosure and therefore may contain information that does not constitute relevant art. Summary of the invention

[0006] Aspects of some embodiments of the present disclosure provide a secondary battery in which an inner surface of a can is coated to insulate an electrode assembly and the can from each other and to improve heat resistance of the can.

[0007] According to some embodiments, a cylindrical secondary battery includes: an electrode assembly; a can accommodating the electrode assembly, wherein one end of the can is open and wherein the can is configured to be electrically connected to the electrode assembly; a cover plate coupled to the one end of the can; and a rivet terminal insulated from the can and the cover plate, wherein the cover plate is configured to seal the one end of the can and be insulated from the can, and wherein a first coating is provided on at least a portion of an inner surface of the can.

[0008] The can may include a top surface portion and a side surface portion extending from an edge of the top surface portion, and the first coating layer may not be provided on a portion of the side surface portion located at the one end of the can.

[0009] A second coating may be provided on a portion of the outer surface of the can.

[0010] The can may include a top surface portion in which a terminal hole is provided, through which the rivet terminal passes, and the can further includes a side surface portion extending from an edge of the top surface portion, and the second coating may be configured to surround the terminal hole.

[0011] The second coating layer may have a size corresponding to a size of the rivet terminal.

[0012] The second coating layer may have a size larger than a size of the rivet terminal.

[0013] The first coating layer may have a thickness of about 0.01 mm to about 0.03 mm.

[0014] The first coating layer may be provided to the side surface portion and may be provided to the top surface portion. A thickness of the first coating layer provided to the side surface portion may be thinner than a thickness of the first coating layer provided to the top surface portion.

[0015] The first coating layer may be provided using an organic / inorganic hybrid coating solution.

[0016] The organic / inorganic hybrid coating solution may be made of resin and nano-ceramic or nano-metal oxide.

[0017] An inwardly concave curled portion may be provided in the side surface portion of the can, and the first coating layer may not be provided in the curled portion.

[0018] The electrode assembly may include a positive electrode plate, a negative electrode plate, and a separator, and the electrode assembly may further include a negative electrode current collecting plate and a positive electrode current collecting plate, wherein the negative electrode current collecting plate contacts the crimping portion to electrically connect the can to the negative electrode plate, and the positive electrode current collecting plate is configured to electrically connect the rivet terminal to the positive electrode plate.

[0019] A crimping portion spaced apart from the crimping portion and bent inwardly may be provided in the one end of the can, and the first coating layer may not be provided from the crimping portion to the crimping portion.

[0020] A first gasket may be interposed between the can and the rivet terminal.

[0021] A second gasket may be interposed between the can and the positive electrode current collecting plate.

[0022] A third gasket may be interposed between the can and the cover plate.

[0023] According to some embodiments, a method for manufacturing a cylindrical secondary battery includes: providing a can for accommodating an electrode assembly, wherein a portion of the can includes an opening, and wherein the can is configured to be electrically connected to the electrode assembly; forming a first coating on at least a portion of an inner surface of the can; inserting the electrode assembly through the opening; connecting a cover plate to the portion of the can; and inserting a rivet terminal into a terminal hole provided in a top surface portion of the can, wherein the rivet terminal is insulated from the can and the cover plate, and wherein the cover plate is configured to seal the portion of the can and be insulated from the can.

[0024] The first coating layer may not be formed on the portion of the can.

[0025] The method may further include forming a second coating on a portion of the outer surface of the can, wherein the second coating is configured to surround the terminal hole.

[0026] The first coating layer may be formed using an organic / inorganic hybrid coating solution. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 A perspective view illustrating a cylindrical secondary battery according to some embodiments;

[0028] Figure 2 Example Figure 1 A cross-sectional view of a cylindrical secondary battery;

[0029] Figure 3 Example Figure 2 An enlarged cross-sectional view of a portion A in a cylindrical secondary battery;

[0030] Figure 4 a bottom perspective view illustrating a configuration in which a negative electrode current collecting plate is coupled to a lower portion of a cylindrical can;

[0031] Figure 5 Example tank from Figure 1 A bottom perspective view of a cylindrical secondary battery in a separated state; and

[0032] Figure 6 A perspective view illustrating a can of a cylindrical secondary battery according to other embodiments. DETAILED DESCRIPTION

[0033] The embodiments of the present disclosure may be implemented in many different forms and should not be construed as being limited to the embodiments set forth herein; rather, these embodiments are provided so that those skilled in the art will have a thorough understanding of the present disclosure. These embodiments are provided so that the present disclosure will be thorough and complete, and fully convey the scope of the present disclosure to those skilled in the art.

[0034] In addition, in the drawings, the thickness or size of each layer is exaggerated for convenience and clarity of description, and the same reference numerals in the drawings designate the same elements.

[0035] As used herein, the term "and / or" includes any and all combinations of one or more associated listed items. In this specification, it will also be understood that if component A is referred to as being connected to component B, component A can be directly connected to component B, or indirectly connected to component B using component C between them.

[0036] The terms used in this specification are only for the exemplary purposes of the present disclosure, and should not be interpreted as limiting the meaning or scope of the present disclosure. As used in this specification, the singular form may include the plural form, unless a particular case is clearly indicated from the perspective of the context. In addition, the expressions "including" and / or "comprising" used in this specification only specify the existence of the shapes, numbers, steps, operations, components, elements and / or combinations thereof mentioned, but do not exclude the existence or addition of one or more other different shapes, numbers, steps, operations, components, elements and / or combinations thereof.

[0037] As used herein, terms such as "first", "second", etc. are used to describe various components, parts, regions, layers and / or parts. However, it is apparent that components, parts, regions, layers and / or parts should not be limited by these terms. These terms do not imply a particular order, top or bottom, or superiority, and are only used to distinguish one component, component, region, layer or part from another component, component, region, layer or part. Therefore, the first component, component, region, layer or part to be described may also be referred to as the second component, component, region, layer or part without departing from the teachings of the present disclosure.

[0038] For ease of description, spatially relative terms such as “below,” “under,” “down,” “above,” “on,” etc. may be used herein to describe the relationship of one element or feature as illustrated in the figures to another element or feature. These spatially relative terms are intended to facilitate understanding of the present technology according to various process states or usage states of the present invention, and therefore, the present disclosure is not limited thereto. For example, if the elements or features shown in the drawings are turned upside down, the elements or features described as “below” or “below” may become “above” or “on.” Therefore, the term “below” may encompass the terms “on” or “below.”

[0039] As described herein, a cylindrical secondary battery may include a cylindrical electrode assembly, a cylindrical can containing the electrode assembly and an electrolyte, and a cap assembly of the sealed can. The cap assembly may be electrically connected to the electrode assembly to electrically connect an external component to the electrode assembly. The electrode assembly may have a shape in which a negative electrode plate, a positive electrode plate, and a separator between the negative electrode plate and the positive electrode plate are wound into a cylindrical shape.

[0040] Here, because insulation is required between the electrode assembly and the inner surface of the can, the outside of the electrode assembly may have to be wrapped with an insulating tape, or an insulator may have to be inserted between the electrode assembly and the can. However, in order to delay the side surface of the can from being melted by heat if an internal event occurs, the thickness of the can must be increased. However, there may be a limitation in that if the thickness of the can increases, the internal space decreases.

[0041] Hereinafter, a cylindrical secondary battery according to an embodiment of the present disclosure will be described in detail with reference to the accompanying drawings.

[0042] Figure 1 A perspective view illustrating a cylindrical secondary battery according to some embodiments. Figure 2 As an example Figure 1 Cross-sectional view of a cylindrical secondary battery. Figure 3 Example Figure 2 An enlarged cross-sectional view of a portion A of a cylindrical secondary battery. Figure 4 A bottom perspective view illustrating a configuration in which a negative electrode current collecting plate is coupled to a lower portion of a cylindrical can. Figure 5 Example tank from Figure 1 A bottom perspective view of a cylindrical secondary battery in a separated state.

[0043] refer to Figure 1 and Figure 2 , the secondary battery 100 according to some embodiments may include a can 110, an electrode assembly 120 accommodated inside the can 110, a positive electrode current collecting plate 130 and a negative electrode current collecting plate 140 electrically connected to the electrode assembly 120, a rivet terminal 150 coupled to a terminal hole provided at one end of the can 110, and a cap plate 160 sealing an opening at the other end of the can 110. A plurality of gaskets 111b, 111c may be provided to insulate the rivet terminal 150 and the can 110 from each other and to insulate the positive electrode current collecting plate 130 and the can 110 from each other. In some embodiments, an additional gasket 170 may be provided to insulate the cap plate 160 and the can 110 from each other.

[0044] The can 110 may be provided in a cylindrical shape, and may include a circular top surface portion 111 and a side surface portion 112 extending downward by a predetermined length from an edge of the top surface portion 111. The top surface portion 111 and the side surface portion 112 of the can 110 may be integrated with each other.

[0045] The circular top surface portion 111 may have a flat circular plate shape and may include a terminal hole 111a passing through a central portion thereof. The rivet terminal 150 may be inserted into and coupled to the terminal hole 111a. A first gasket 111b such as for sealing and electrical insulation may be between the terminal hole 111a and the rivet terminal 150. The first gasket 111b may prevent contact between the rivet terminal 150 and the tank 110 to electrically separate the rivet terminal 150 and the tank 110 from each other. One or more first gaskets 111b may be provided. In some embodiments, the terminal hole 111a of the top surface portion 111 may be sealed by the first gasket 111b. The first gasket 111b may be made of a resin material such as polyethylene (PE), polypropylene (PP), polyethylene terephthalate (PET) or the like.

[0046] In the cylindrical secondary battery 100, the lower portion of the tank 110 may be open during the manufacturing process. In some embodiments, during the process of manufacturing the cylindrical secondary battery 100, the electrode assembly 120 may be inserted through the open lower portion of the tank 110 together with the electrolyte. In some embodiments, the electrolyte and the electrode assembly 120 may be inserted into the tank 110 when the open lower portion faces the upper side. After the electrolyte and the electrode assembly 120 are inserted into the tank 110, the cap plate 160 may be coupled to the open lower end to seal the tank 110. Here, the electrolyte is used to enable lithium ions to move between the positive electrode plate 121 and the negative electrode plate 122 constituting the electrode assembly 120. The electrolyte may be a non-aqueous organic electrolyte that is a mixture of a lithium salt and a high-purity organic solvent. In addition, the electrolyte may be a polymer electrolyte or a solid electrolyte using a polymer, and the type of the electrolyte is not so limited here.

[0047] The can 110 may be made of steel, steel alloy, aluminum, aluminum alloy, or its equivalent, but the material is not limited thereto. In some embodiments, a crimping portion 113 and a crimping portion 114 may be provided on a side surface portion 112 of the can 110. The crimping portion 113 may be provided by recessing a portion of the side surface portion 112 inwardly to prevent the electrode assembly 120 from being separated to the outside. The crimping portion 114 may be provided by bending the end of the side surface portion 112 spaced apart from the crimping portion 113 inwardly. That is, relative to the center of the cover plate 160, the crimping portion 113 may be provided on the upper side, and the crimping portion 114 may be provided on the lower side.

[0048] In the can 110, after the electrode assembly 120 is inserted through the open lower end of the can 110, the crimping portion 113 may be provided to prevent the electrode assembly 120 from being separated from the can 110. That is, the lower edge of the electrode assembly 120 may be placed on the crimping portion 113. In some embodiments, the lower edge of the electrode assembly 120 may be placed on a flat portion of an upper portion of the crimping portion 113.

[0049] The electrode assembly 120 may include a positive electrode plate 121 coated with a positive electrode active material, a negative electrode plate 122 coated with a negative electrode active material, and a separator 123 between the positive electrode plate 121 and the negative electrode plate 122. In the electrode assembly 120, the positive electrode plate 121, the negative electrode plate 122, and the separator 123 may be stacked and then wound into a substantially cylindrical shape. In some embodiments, the positive electrode uncoated portion of the positive electrode plate 121, which is not coated with the positive electrode active material, may protrude toward the upper side of the electrode assembly 120. The negative electrode uncoated portion of the negative electrode plate 122, which is not coated with the negative electrode active material, may protrude toward the lower side of the electrode assembly 120.

[0050] In the positive electrode plate 121, at least one surface of the positive electrode plate, which may be a plate-shaped metal foil made of aluminum (Al), may be coated with a positive electrode active material made of a transition metal oxide. In some embodiments, the positive electrode plate 121 may be provided at its upper end with a positive electrode uncoated portion on which the positive electrode active material is not coated. As described above, the positive electrode uncoated portion may protrude toward the upper side of the electrode assembly 120. That is, the positive electrode uncoated portion of the positive electrode plate 121 may protrude further upward than the negative electrode plate 122 and the separator 123.

[0051] In the negative electrode plate 122, at least one surface of the negative electrode plate, which may be a plate-shaped metal foil made of copper (Cu) or nickel (Ni), may be coated with a negative electrode active material (such as graphite or carbon). In addition, the negative electrode plate 122 may be provided at its lower end with a negative electrode uncoated portion on which the negative electrode active material is not coated. As described above, the negative electrode uncoated portion may protrude toward the lower side of the electrode assembly 120. That is, the negative electrode uncoated portion of the negative electrode plate 122 may protrude further downward than the positive electrode plate 121 and the separator 123.

[0052] The separator 123 may be made of polyethylene (PE) or polypropylene (PP), but the embodiment is not limited thereto. The separator may prevent an electrical short circuit between the positive electrode plate 121 and the negative electrode plate 122 and may allow only lithium ions to move.

[0053] The positive electrode current collecting plate 130 may be a circular metal plate having a shape corresponding to the top surface of the electrode assembly 120. The plane size of the positive electrode current collecting plate 130 may be equal to or smaller than the plane size of the upper portion of the electrode assembly 120. The positive electrode current collecting plate 130 may be made of aluminum (Al). The bottom surface of the positive electrode current collecting plate 130 may be fixed by welding and electrically connected to the positive electrode uncoated portion that may be exposed on the upper side of the electrode assembly 120. The top surface of the positive electrode current collecting plate 130 may be fixed by welding and electrically connected to the rivet terminal 150 so that the top surface of the positive electrode current collecting plate contacts the bottom surface of the rivet terminal 150. The positive electrode current collecting plate 130 may serve as a path for current flow between the positive electrode plate 121 of the electrode assembly 120 and the rivet terminal 150. In some embodiments, the second gasket 111c may be provided between (e.g., between) the positive electrode current collecting plate 130 and the top surface portion 111 of the can 110. The size of the second gasket 111 c may be equal to or greater than that of the positive electrode current collecting plate 130 .

[0054] refer to Figures 2 to 4 , the negative electrode current collecting plate 140 may include a circular plane portion 141 corresponding to the bottom surface of the electrode assembly 120 and an extension portion 142 extending downward from the edge of the plane portion 141. The top surface of the plane portion 141 may be in contact with the bottom surface of the electrode assembly 120. The top surface of the plane portion 141 may be fixed and electrically connected to the negative electrode uncoated portion exposed at the lower side of the electrode assembly 120 by welding to contact the bottom surface of the electrode assembly 120.

[0055] The extension portion 142 may be provided in a plurality of portions spaced apart from each other along the edge of the plane portion 141 . Figure 4 A bottom perspective view illustrating a state in which the negative electrode current collecting plate 140 is placed on the crimping portion 113 after the crimping portion 113 is provided in the can 110. Figure 4 , the extension portion 142 is illustrated as having four portions symmetrical to each other relative to the plane portion 141, but is not limited thereto. The extension portion 142 may be bent downward from the edge of the plane portion 141 to extend. The extension portion 142 may be fixed to the crimping portion 113. In some embodiments, the extension portion 142 may be welded to contact the flat portion of the lower portion of the crimping portion 113, and thus may be fixed and electrically connected to the can 110. The negative electrode current collecting plate 140 may serve as a path for current flow between the negative electrode plate 122 of the electrode assembly 120 and the can 110. In some embodiments, reference Figure 4 , the welding of the extension portion 142 and the crimping portion 113 may be performed before providing the crimping portion 114 of the can 110 .

[0056] The rivet terminal 150 may be inserted into a terminal hole 111a provided in the top surface portion 111 of the can 110, pass through the terminal hole, and be electrically connected to the positive electrode current collecting plate 130. The rivet terminal 150 may be made of a material that is the same as or similar to that of each of the positive electrode current collecting plate 130 and the positive electrode plate 121, such as, but not limited to, aluminum (Al). Each of the diameter of the portion of the rivet terminal 150 exposed to the upper side of the can 110 and the diameter of the portion of the rivet terminal 150 disposed inside the can 110 may be greater than the diameter of the portion of the rivet terminal 150 disposed in the terminal hole 111a. For simplicity, the portion exposed to the upper side of the can 110 will be referred to as the upper end of the rivet terminal 150, and the portion disposed inside the can 110 to face the electrode assembly 120 will be referred to as the lower end of the rivet terminal 150. After the rivet terminal 150 is coupled to the terminal hole 111a from the lower side upward (e.g., from the bottom to the top), the upper end may be compressed and deformed by a processing method such as extrusion or spinning to be in close contact with the top surface portion 111. On the contrary, in some embodiments, the rivet terminal 150 may be inserted into the terminal hole 111a from the outside of the can 110, and then the lower end of the rivet terminal 150 may be compressed and deformed to be in close contact with the inner side of the top surface portion 111. In some embodiments, the first gasket 111b may be interposed between the rivet terminal 150 and the terminal hole 111a to electrically insulate the rivet terminal 150 and the can 110 from each other. The rivet terminal 150 may be electrically connected to the positive electrode plate 121 of the electrode assembly 120 through the positive electrode current collecting plate 130.

[0057] The cover plate 160 may be a circular metal plate and may be coupled to the lower end of the tank 110. The cover plate 160 may be coupled to the lower end of the tank 110 while the third gasket 170 is inserted to prevent the cover plate from being electrically connected to the tank 110. Because the cover plate 160 is not electrically connected to the positive electrode or the negative electrode of the electrode assembly 120 in some embodiments, the cover plate 160 may not have a separate electrical polarity. In some embodiments, a notch 162 may be provided in the cover plate 160 to open at a set pressure. If the internal pressure of the tank 110 exceeds the rupture pressure, the notch 162 may rupture to discharge the internal gas. That is, if an excessive internal pressure is generated inside the tank 110, the notch 162 may rupture, so that the excessive internal pressure can be reduced.

[0058] The cover plate 160 may be fixed by forming a crimping portion 114 at the lower end of the can 110 so that the edge of the cover plate 160 is placed on the lower portion of the crimping portion 113 of the can 110. Here, the cover plate 160 may be placed on the crimping portion 113 in a state where the open lower portion faces the upper side. In some embodiments, the cover plate 160 may be placed on the lower portion of the crimping portion 113 of the can 110 in a state where the third gasket 170 is interposed between the cover plate 160 and the lower portion of the crimping portion 113 of the can 110. Thereafter, the crimping portion 114 of the can 110 may be bent in an inward direction of the cover plate 160 to press the third gasket 170, thereby coupling the cover plate 160 to the can 110.

[0059] The third gasket 170 may be made of a resin material such as polyethylene (PE), polypropylene (PP), polyethylene terephthalate (PET), or the like. The third gasket 170 may compress and seal a gap between the can 110 and the cover plate 160. The third gasket 170 may prevent the cover plate 160 from being separated from the can 110.

[0060] refer to Figure 5 In some embodiments, the first coating 180 may be provided on a portion of the inner surface of the can 110. The first coating 180 may be provided using an organic / inorganic hybrid coating solution. The organic / inorganic hybrid coating solution may be made of a resin and a nano-ceramic or a nano-metal oxide and / or may be provided as a resin and a nano-ceramic or a nano-metal oxide to have chemical resistance (e.g., electrolyte resistance), insulation, adhesion, and heat resistance. For example, the resin may correspond to polyamideimide (PAI, e.g., ), silicone, epoxy resin, PP resin, etc. The first coating layer 180 may be used as an insulating layer inside the can 110 .

[0061] Figure 5 The can 110 is illustrated before the crimping portion 113 and the crimping portion 114 are formed. In some embodiments, the first coating 180 may be provided on some portions of the inner surface of the top surface portion 111 and the inner surface of the side surface portion 112 of the can 110. In some embodiments, the first coating 180 may not be provided on one end of the open side of the side surface portion 112. In other words, the first coating 180 may not be provided on the portion of the side surface portion 112 located at the open end of the can 110. This may be because in some embodiments the can 110 must be electrically connected by contacting the negative electrode current collecting plate 140 through the crimping portion 113.

[0062] As described above, since the negative electrode current collecting plate 140 contacts the crimping portion 113 of the can 110, the first coating layer 180 should not be provided on the crimping portion 113. In some embodiments, the first coating layer 180 may be provided from the upper portion of the side surface portion 112 of the can 110 to the crimping portion 113 (corresponding to the upper portion 112 of the can 110). Figure 5 In some embodiments, from the crimping portion 113 to the crimping portion 114 (corresponding to Figure 5 The first coating layer 180 may not be provided in the portion (b) in the crimping portion 114. Even if the first coating layer 180 is not provided in the crimping portion 114, the cover plate 160 may be insulated from the can 110 because the third liner 170 is interposed between the can 110 and the cover plate 160. However, the embodiment is not limited thereto, and the first coating layer 180 may be provided not only in the crimping portion 113 but also in the crimping portion 114. That is, the third liner 170 may not be provided, or the first coating layer 180 may be provided on the region of the crimping portion 114 for additional insulation purposes.

[0063] Accordingly, the can 110 may be electrically connected to the negative electrode current collecting plate 140, and the first coating layer 180 may be provided on the inner surface facing the electrode assembly 120. In some embodiments, the electrode assembly 120 and the can 110 may be insulated from each other by the first coating layer 180. In some embodiments, components such as insulating tape or an insulator, each of which may generally have a thickness of about 0.3 mm to about 0.8 mm, may be removed and / or not included, and the first coating layer 180 may be provided to have a thinner thickness, so that the internal space of the can 110 may be expanded. The first coating layer 180 may have a thickness of about 0.01 mm to about 0.03 mm.

[0064] In some embodiments, the thickness of the first coating layer 180 coated on the side surface portion 112 of the can 110 may be thinner than the thickness of the first coating layer 180 coated on the top surface portion 111 .

[0065] As described above, a portion of the inner surface of the tank 110 can be coated with an organic / inorganic hybrid coating solution to improve the heat resistance of the tank, and the thickness of the tank can be reduced, so the internal space of the tank can be expanded. As a result, the capacity of the secondary battery can be increased due to the expansion of the internal space of the tank, and if the same capacity is achieved, the cost can be reduced.

[0066] In some embodiments, during the manufacturing process of the can 110, the can 110 may be formed to have a top surface portion 111 and a side surface portion 112, and then may be coated after cleaning. In the coating process, the first coating 180 may be formed by the organic / inorganic hybrid coating solution described herein. Thereafter, the first coating 180 may be cured by high temperature drying or UV curing.

[0067] Next, we will refer to Figure 6 Cylindrical secondary batteries according to other embodiments are described.

[0068] Figure 6A perspective view illustrating a can of a cylindrical secondary battery according to other embodiments.

[0069] In some embodiments, the structure of the cylindrical secondary battery 100 may be the same as described above. Figure 1 However, in addition to the first coating layer 180 provided on a portion of the inner surface of the can 110 , the second coating layer 190 may be additionally provided on a portion of the outer surface of the can 110 .

[0070] Figure 6 The can 110 is shown before the crimping portion 113 and the crimping portion 114 are formed. Figure 6 In some embodiments, the first coating layer 180 may be provided on at least a portion of the inner surface of the top surface portion 111 and the inner surface of the side surface portion 112 of the can 110. In some embodiments, the first coating layer 180 may be provided from the upper side of the side surface portion 112 of the can 110 up to the crimping portion 113, and the first coating layer 180 may not be provided from the crimping portion 113 to the crimping portion 114. However, it is not limited thereto, and the first coating layer 180 may be provided not only in the crimping portion 113 but also in the crimping portion 114 (as an example, from the crimping portion to the crimping portion).

[0071] Accordingly, the can 110 may be electrically connected to the negative electrode current collecting plate 140, and the first coating layer 180 may be provided on the inner surface facing the electrode assembly 120, and thus the electrode assembly 120 and the can 110 may be insulated from each other. In some embodiments, components such as an insulating tape or an insulator may be removed and / or may not be included, each of which may generally have a thickness of about 0.3 mm to about 0.8 mm, and the first coating layer 180 may be provided to have a thinner thickness, and thus the inner space of the can 110 may be expanded. The first coating layer 180 may have a thickness of about 0.01 mm to about 0.03 mm.

[0072] In some embodiments, the thickness of the first coating 180 provided to (eg, applied to) the side surface portion 112 of the can 110 may be thinner than the thickness of the first coating 180 provided to (eg, applied to) the top surface portion 111 .

[0073] The second coating 190 may be provided around the terminal hole 111a formed in the top surface portion 111 of the tank 110. In some embodiments, the second coating 190 may surround the terminal hole 111a and have a circular shape corresponding to the shape of the rivet terminal 150. In some embodiments, the outer surfaces of the rivet terminal 150 and the tank 110 may be insulated from each other. Because the first liner 111b is between the rivet terminal 150 and the tank 110 to act as a seal, the first liner 111b may not be removed. However, because the second coating 190 is provided, the thickness of the first liner 111b may be reduced. The second coating 190 may also have a thickness of about 0.01mm to about 0.03mm. If the thickness of the first liner 111b is reduced, the height of the rivet terminal 150 protruding upward may be reduced. The size of the tank 110 may be increased due to the protruding height of the rivet terminal 150. As a result, the capacity of the secondary battery may be increased due to the expansion of the internal space of the tank.

[0074] To this end, the second coating 190 may have a size corresponding to the size of the rivet terminal 150 (more precisely, the size of the upper end of the rivet terminal 150). In some embodiments, in order to increase reliable insulation, the second coating 190 may have a size larger (e.g., larger) than the size of the rivet terminal 150.

[0075] The first coating layer 180 and the second coating layer 190 may be provided using an organic / inorganic hybrid coating solution. The organic / inorganic hybrid coating solution may be provided as a resin and a nano-ceramic or a nano-metal oxide to have chemical resistance (e.g., electrolyte resistance), insulation, adhesion, and heat resistance. For example, the resin may correspond to polyamide-imide (PAI, e.g. ), silicone, epoxy resin, PP resin, etc.

[0076] As described above, at least a portion of each of the inner and outer surfaces of the tank 110 may be coated with an organic / inorganic hybrid coating solution to improve the heat resistance of the tank, and the thickness of the tank may be reduced, thereby expanding the internal space of the tank. As a result, the capacity of the secondary battery may be increased due to the expansion of the internal space of the tank, and if the same capacity is achieved, the cost may be reduced.

[0077] According to an embodiment, the inner surface of the can may be coated with an organic / inorganic hybrid coating solution to insulate the electrode assembly and the can from each other, and since an insulating tape or an insulator may be removed, the inner space of the can may be expanded.

[0078] In some embodiments, the heat resistance of the can can be improved, and the thickness of the can can be reduced, so that the internal space of the can can be expanded.

[0079] As described above, the capacity of the secondary battery can be increased due to the expansion of the internal space of the can, and if the same capacity is achieved, the cost can be reduced.

[0080] In some embodiments, if necessary, the outer surface around the terminal hole of the tank can be additionally coated to insulate the rivet terminal from the outer surface of the tank. Therefore, the thickness of the gasket used to seal the gap between the rivet terminal and the tank and insulate the rivet terminal from the tank can be reduced.

[0081] According to some embodiments, a method for manufacturing a cylindrical secondary battery is provided, the method including providing a can for accommodating an electrode assembly, wherein a portion of the can includes an opening, and wherein the can is configured to be electrically connected to the electrode assembly; forming a first coating on at least a portion of an inner surface of the can; inserting the electrode assembly through the opening; coupling a cover plate to the portion of the can; and inserting a rivet terminal into a terminal hole provided in a top surface portion of the can, wherein the rivet terminal is insulated from the can and the cover plate, and wherein the cover plate is configured to seal the portion of the can and be insulated from the can.

[0082] According to some embodiments, the first coating layer may not be formed on the portion of the can, and the portion may be a portion of a side surface portion of the can.

[0083] According to some embodiments, the method may include forming a second coating on a portion of the outer surface of the can, wherein the second coating is configured to surround the terminal aperture.

[0084] According to some embodiments, the first coating layer may be formed using an organic / inorganic hybrid coating solution.

[0085] The above-described embodiments are merely example embodiments, and thus the present disclosure is not limited to the foregoing embodiments, and persons of ordinary skill in the art will appreciate that various changes in form and details may be made therein without departing from the spirit and scope of the present disclosure as defined in the claims.

[0086] The term "approximately" may be used in some embodiments to mean within ±20% of a target value, in some embodiments to mean within ±10% of a target value, and in some embodiments to mean within ±5% of a target value. The term "approximately" may be equal to a target value.

Claims

1. A cylindrical secondary battery, comprising: Electrode assembly; a can accommodating the electrode assembly, wherein one end of the can is open, and wherein the can is configured to be electrically connected to the electrode assembly; a cover plate coupled to the one end of the tank; and Rivet terminals, insulated from the tank and the cover, wherein the cover plate is configured to seal the one end of the tank and insulate the tank, and Wherein a first coating is provided on at least a portion of the interior surface of the can.

2. The cylindrical secondary battery according to claim 1, wherein the can includes a top surface portion and a side surface portion extending from an edge of the top surface portion, and wherein the first coating is not provided on a portion of the side surface portion located at the one end of the can. 3 . The cylindrical secondary battery according to claim 1 , wherein a second coating layer is provided on a portion of an outer surface of the can.

4. The cylindrical secondary battery according to claim 3, wherein the can includes a top surface portion, a terminal hole is provided in the top surface portion, the rivet terminal passes through the terminal hole, and wherein the can further includes a side surface portion extending from an edge of the top surface portion, and The second coating is configured to surround the terminal hole. 5 . The cylindrical secondary battery according to claim 4 , wherein the second coating layer has a size corresponding to a size of the rivet terminal. 6 . The cylindrical secondary battery according to claim 4 , wherein the second coating layer has a size larger than a size of the rivet terminal. 7 . The cylindrical secondary battery according to claim 1 , wherein the first coating layer has a thickness of 0.01 mm to 0.03 mm.

8. The cylindrical secondary battery according to claim 2, wherein the first coating layer is provided to the side surface portion and to the top surface portion, and wherein a thickness of the first coating layer provided to the side surface portion is thinner than a thickness of the first coating layer provided to the top surface portion. 9 . The cylindrical secondary battery according to claim 1 , wherein the first coating layer is provided using an organic / inorganic hybrid coating solution. 10 . The cylindrical secondary battery according to claim 9 , wherein the organic / inorganic hybrid coating solution is made of resin and nano-ceramic or nano-metal oxide.

11. The cylindrical secondary battery according to claim 2, wherein an inwardly concave curling portion is provided in the side surface portion of the can, and Wherein the first coating is not provided in the crimping portion.

12. The cylindrical secondary battery according to claim 11, wherein the electrode assembly comprises a positive electrode plate, a negative electrode plate and a separator, and The electrode assembly further includes a negative electrode current collecting plate contacting the crimping portion to electrically connect the can to the negative electrode plate and a positive electrode current collecting plate configured to electrically connect the rivet terminal to the positive electrode plate.

13. The cylindrical secondary battery according to claim 11, wherein a crimping portion spaced apart from the crimping portion and bent inwardly is provided in the one end of the can, and The first coating is not provided from the crimping portion to the crimping portion. 14 . The cylindrical secondary battery according to claim 1 , wherein a first gasket is interposed between the can and the rivet terminal. 15 . The cylindrical secondary battery according to claim 12 , wherein a second gasket is interposed between the can and the positive electrode current collecting plate. 16 . The cylindrical secondary battery according to claim 1 , wherein a third gasket is interposed between the can and the cap plate.

17. A method for manufacturing a cylindrical secondary battery, the method comprising: providing a can to house an electrode assembly, wherein a portion of the can includes an opening, and wherein the can is configured to be electrically connected to the electrode assembly; forming a first coating on at least a portion of the inner surface of the can; inserting the electrode assembly through the opening; coupling a cover plate to the portion of the tank; as well as inserting a rivet terminal into a terminal hole provided in a top surface portion of the can, wherein the rivet terminal is insulated from the can and the cover plate, and The cover plate is configured to seal the portion of the tank and insulate the tank.

18. The method of claim 17, wherein the first coating is not formed on the portion of the can.

19. The method of claim 17, further comprising forming a second coating on a portion of the outer surface of the can, wherein the second coating is configured to surround the terminal hole.

20. The method of claim 17, wherein the first coating layer is formed using an organic / inorganic hybrid coating solution.

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