Secondary battery including cover plate for improving sealing force

Abstract

Disclosed is a secondary battery including a cap plate for improving sealing force. The secondary battery includes: an electrode assembly; a case including an opening into which the electrode assembly is inserted; and the cover plate comprises a joint area welded with the shell, and the cover plate is used for closing the opening. The joining region may include: one or more support surfaces that come into contact with the housing and are supported; and one or more chambers formed by separating a part of the bonding region from the housing by a support surface.

Description

Technical Field

[0001] The present disclosure relates to a secondary battery including a cover plate with improved sealing force. Background Art

[0002] A secondary battery is an energy storage device capable of charging and discharging. Secondary batteries are widely used in various devices powered by electricity. For example, secondary batteries are used as energy storage devices in various devices from small devices such as mobile phones, laptops, and tablets to large devices such as vehicles and aircraft. In particular, in recent years, there has been active exploration of using secondary batteries as the power source for vehicles.

[0003] According to the different electrode materials, secondary batteries can be classified into lead-acid batteries, nickel-cadmium batteries, nickel-metal hydride batteries, lithium-ion batteries, etc. Various types of secondary batteries can be appropriately selected according to the design capacity, use environment, etc. Compared with other types of secondary batteries, lithium-ion batteries can achieve relatively high voltages and capacities. Therefore, lithium-ion batteries are widely used in fields that require high-density energy storage devices such as vehicle battery packs.

[0004] The main components of secondary batteries such as lithium-ion batteries include a positive electrode material, a negative electrode material, a separator, an electrolyte, etc. A separator made of an insulating material is provided between the positive electrode material and the negative electrode material, and charging or discharging can be performed through the movement of ions in the electrolyte.

[0005] An electrode assembly including a positive electrode material, a negative electrode material, a separator, etc. can be accommodated inside a housing. In some types of secondary batteries, the housing can be generally in a cuboid shape. In this case, an opening for inserting the electrode assembly can be formed at the upper end of the housing, and the opening can be closed by a cover plate. Generally, the cover plate can be joined to the housing by welding the edge portion where the cover plate contacts the housing. In the prior art, various welding joining methods between the cover plate and the housing have been proposed. For example, a technique has been proposed to improve the sealing performance by forming a chamfer at the edge of the portion where the cover plate contacts the can (housing).

[0006] The above description is provided to help understand the technical background of the present disclosure and should not be construed as narrowing, limiting, or restricting the technical idea of the present disclosure. In addition, the content described or recited in the above description does not necessarily mean prior art and may also include content that is not prior art. Summary of the Invention

[0007] (I) Technical Problems to be Solved

[0008] According to an embodiment of the present disclosure, a secondary battery capable of improving the bonding structure between the cover plate and the housing can be provided.

[0009] According to an embodiment of the present disclosure, a secondary battery capable of preventing damage to an insulating coating due to welding heat can be provided.

[0010] According to an embodiment of the present disclosure, a secondary battery capable of more effectively maintaining a sealing structure between a cover plate and a case during inflation can be provided.

[0011] However, the technical problems to be solved by the embodiments of the present disclosure are not necessarily limited to the above technical problems. Those of ordinary skill in the technical field to which the present disclosure pertains can clearly understand other technical problems not mentioned from other descriptions in the detailed description and other parts of the specification.

[0012] The secondary battery of the present disclosure can be widely applied to electric vehicles, battery charging stations, and other green technology fields such as solar power generation and wind power generation that use batteries. In addition, the secondary battery of the present disclosure can be used in eco-friendly electric vehicles (EVs), hybrid vehicles, etc. that prevent climate change by suppressing air pollution and greenhouse gas emissions.

[0013] (II) Technical Solution

[0014] The secondary battery according to the present disclosure may include: an electrode assembly; a case including an opening for inserting the electrode assembly; and a cover plate including a bonding area welded to the case, and the cover plate is used to close the opening. The bonding area may include: one or more support surfaces in contact with and supported by the case; and one or more chambers formed by a part of the bonding area being separated from the case through the support surface.

[0015] According to one embodiment, the chamber may be arranged to be connected to a bead formation site for bonding with the case to accommodate by-products generated during welding.

[0016] According to one embodiment, the chamber may include a plurality of chambers, the plurality of chambers may be arranged to be separated by the support surface, and one or more of the plurality of chambers may be connected to a bead formation site for bonding with the case.

[0017] According to one embodiment, an insulating coating may be included on an inner side surface of the case, the cover plate may include a bead for bonding with the case, and the support surface and the chamber may be provided between the bead and the insulating coating.

[0018] According to one embodiment, the support surface may include a plurality of support surfaces, the chamber may include a plurality of chambers, and the plurality of support surfaces and the plurality of chambers may be repeatedly and alternately arranged along the bonding area.

[0019] According to one embodiment, the support surface may include a plurality of support surfaces, and the plurality of support surfaces may be configured such that when the housing is deformed, more than one of the plurality of support surfaces remains in contact with the inner side surface of the housing.

[0020] According to one embodiment, the bonding region may include: a first extending rib formed to extend upward from an edge portion of the cover plate, and at least a portion of the first extending rib is disposed at a distance from the inner side surface of the housing through the support surface; and a second extending rib formed to extend laterally from the first extending rib to form a bead for bonding the housing.

[0021] According to one embodiment, the first extending rib may include one or more support ribs, the support ribs may be formed to extend toward the inner side surface of the housing, and the end portions of the support ribs may be in contact with and supported by the inner side surface of the housing to form the support surface.

[0022] According to one embodiment, the support ribs may include a plurality of support ribs, and the plurality of support ribs may be spaced apart from each other at a predetermined interval along the first extending rib to form the chamber between an adjacent pair of support ribs.

[0023] According to one embodiment, the cover plate may include a chamfer formed at a lower end edge portion corresponding to the bonding region to guide the bonding with the housing.

[0024] The bonding region may include a first extending rib formed to extend upward from an edge portion of the cover plate. The first extending rib may repeatedly bend inward and outward toward the inner side surface of the housing and extend, and according to the bending, a part of the first extending rib may be in contact with the inner side surface of the housing to form the support surface, and another part of the first extending rib may be spaced apart from the inner side surface of the housing to form the chamber.

[0025] According to one embodiment, the housing may include a flange that extends laterally from an upper end of the housing toward the outside of the housing to be bonded to the cover plate. The bonding region may be formed to have a plane corresponding to the cover plate and extend laterally.

[0026] The chamber may be formed in a groove shape recessed from a bottom surface of the bonding region, and a plurality of the chambers may be spaced apart from each other laterally along the bonding region, and more than one of the plurality of chambers may be connected to a bead forming portion for bonding with the housing.

[0027] According to one embodiment, the support surface and the chamber may be disposed between an insulating coating formed on an inner side surface of the housing and a bead for joining the cover plate and the housing to limit heat transfer from welding to the insulating coating.

[0028] (III) Advantageous Effects

[0029] A secondary battery according to an embodiment of the present disclosure may include a cover plate including a joining region and joined to a housing by welding. Additionally, the joining region may include a support surface that contacts and is supported by the housing and a chamber formed between the joining region and the housing. In some embodiments, a plurality of the support surfaces and chambers as described above may be provided respectively, and the plurality of support surfaces and the plurality of chambers may be alternately disposed within the joining region.

[0030] The joining region as described above may accommodate by-products generated during welding and limit heat transfer from welding to an insulating coating inside the housing. Accordingly, inflow of welding by-products or damage to the insulating coating may be prevented during the manufacturing process. Additionally, the joining region as described above may effectively cope with deformation of the housing caused by, for example, gas expansion. That is, even when the housing is deformed, the joining region as described above may maintain a sealed state through a plurality of support surfaces. Additionally, each chamber serves as a buffer space for temporarily accommodating heat, pressure, by-products, etc. inside, thereby assisting in maintaining the above-described sealed state.

[0031] However, the technical effects that can be obtained through embodiments of the present disclosure are not necessarily limited to the above effects. Those of ordinary skill in the technical field to which the present disclosure pertains can clearly understand other technical effects not mentioned from other descriptions in the detailed description and other parts of the specification. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1a is a schematic external perspective view of a secondary battery according to one embodiment.

[0033] Figure 1b is Figure 1a a schematic exploded perspective view of the secondary battery shown.

[0034] Figure 1c is Figure 1a a schematic internal cross-sectional view of the secondary battery shown.

[0035] Figure 2a is a schematic perspective view of a cover plate and a housing according to one embodiment.

[0036] Figure 2b is Figure 2a a schematic partial cross-sectional view of the cover plate and the housing shown.

[0037] Figure 2c is Figure 2aAn operating state diagram of the cover plate and the housing shown.

[0038] Figure 3a It is a schematic perspective view of a cover plate and a housing according to another embodiment.

[0039] Figure 3b Is Figure 3a A schematic partial cross-sectional view of the cover plate and the housing shown.

[0040] Figure 4a It is a schematic perspective view of a cover plate and a housing according to yet another embodiment.

[0041] Figure 4b Is Figure 4a A schematic partial cross-sectional view of the cover plate and the housing shown.

[0042] Figure 5a It is a schematic perspective view of a cover plate and a housing according to yet another embodiment.

[0043] Figure 5b Is Figure 5a A schematic partial cross-sectional view of the cover plate and the housing shown.

[0044] Explanation of reference numerals:

[0045] 100: Secondary battery

[0046] 120: Electrode assembly

[0047] 110, 210, 310, 410, 510: Housing

[0048] 130, 220, 320, 420, 520: Cover plate Detailed implementation manners

[0049] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. For convenience, in the following description, detailed descriptions of configurations that obscure the technical gist of the present disclosure or known configurations will be omitted.

[0050] The following embodiments are provided to more completely describe the present disclosure to ordinary technicians in the technical field to which the present disclosure belongs. The following embodiments are provided to help understand the present disclosure, and the technical idea of the present disclosure is not limited to the specific embodiments described below. The present disclosure should be understood to widely include various equivalents, alternatives, transformants, etc. that implement the technical idea described in the following embodiments.

[0051] The terms used in the following embodiments are provided to more completely describe a specific embodiment from the above viewpoints. Therefore, the terms used in the following embodiments should not be construed as aiming to narrow, limit, or restrict the technical idea of the present disclosure.

[0052] In the following description, unless the context clearly excludes the plural, singular expressions may be interpreted to include the plural. Additionally, in the following description, the expression "comprising" means that the described structures, components, operations, features, steps, numbers, etc. exist, and does not mean excluding the addition of one or more other structures, components, operations, features, steps, numbers, etc.

[0053] In the following description, terms such as "first", "second", etc. may be used to distinguish a specific component from other components. However, the purpose of using such terms is to distinguish a specific component from other components for the sake of clear explanation, and the technical concept of each component should not be interpreted restrictively by such terms.

[0054] The secondary battery described in this specification may include a battery capable of charging and discharging. For example, the secondary battery may include a lead-acid battery, a nickel-cadmium battery, a nickel-metal hydride battery, a lithium-ion battery, etc. In this description, it is assumed that the secondary battery is a lithium-ion battery. Generally, a lithium-ion battery may have advantages such as light weight, high energy density, low self-discharge rate, etc. However, it should be understood that the technical concept described in this specification may also be applicable to other suitable types of batteries other than lithium-ion batteries.

[0055] The secondary battery described in this specification may include a single physical unit cell or a cluster unit composed of a combination of multiple such unit cells. For example, according to the classification criteria commonly used in the current vehicle field, the secondary battery may include a battery cell, a battery module, a battery pack, etc. In this specification, it is assumed that the secondary battery is a single unit cell, i.e., a battery cell. Generally, a battery cell is the basic constituent unit of a battery pack including a positive electrode, a negative electrode, a separator, an electrolyte, etc. However, it should be understood that the technical concept described in this specification may be applicable to other suitable types of cluster units such as battery modules and battery packs as needed.

[0056] The secondary battery described in this specification may include various packaging types. For example, according to the classification criteria commonly used in the relevant field currently, the secondary battery may be packaged into a cylindrical shape, a prismatic shape, a pouch shape, etc. In this description, it is assumed that the secondary battery is packaged into a prismatic shape. The prismatic packaging, such as a prismatic battery, usually has advantages in terms of durability, safety, installation convenience, etc. However, it should be understood that the technical concept described in this specification may be applicable to other suitable packaging types such as cylindrical and pouch shapes as needed.

[0057] The secondary battery described in this specification can be used in various devices that require electrical energy. For example, the secondary battery can be applied to the field of vehicles that use electrical energy as the main power source or auxiliary power source. As another example, the secondary battery can be applied to the field of aircraft such as personal aircraft, drones, and unmanned aerial vehicles, the field of electronic devices such as mobile phones, laptops, and tablet computers, and the field of power tools such as electric drills, electric grinders, and electric hammers. However, it should be understood that the secondary battery described in this specification can be widely applied to various devices that operate based on electrical energy other than the above.

[0058] Figure 1a is a schematic external perspective view of a secondary battery according to an embodiment. Figure 1b is Figure 1a a schematic exploded perspective view of the secondary battery shown. Figure 1c is Figure 1a a schematic internal cross-sectional view of the secondary battery shown. For example, Figure 1c is along Figure 1a a cross-sectional view taken along line 1c-1c' of.

[0059] For ease of explanation, in this embodiment, a single battery cell encapsulated in a prismatic shape is shown.

[0060] Referring to Figures 1a to 1c , the secondary battery 100 according to this embodiment may include a housing 110.

[0061] The housing 110 can provide an internal space capable of accommodating the electrode assembly 120 and the like. In this embodiment, the housing 110 is shown as being generally rectangular parallelepiped in shape.

[0062] The housing 110 may include an opening 111 connected to the internal space. In this embodiment, the opening 111 is shown as being provided at the upper end of the housing 110. However, the position of the opening 111 can be changed according to needs and is not necessarily limited to the example shown. The opening 111 can be used as a passage for inserting the electrode assembly 120 and the like. In addition, the opening 111 can be used as a connection space for electrical connection between the electrode assembly 120 and the electrode terminal. The opening 111 can be appropriately closed by a cover plate 130 to be described later.

[0063] The material of the housing 110 can be appropriately selected considering thermal conductivity and electrical conductivity, rigidity corresponding to the swelling of the electrode assembly 120, workability, manufacturing cost, and the like. For example, the housing 110 can be made of a metal material including aluminum, aluminum alloy, and the like.

[0064] On the other hand, the secondary battery 100 according to this embodiment may include an electrode assembly 120.

[0065] The electrode assembly 120 may be disposed in the inner space of the housing 110. As needed, the electrode assembly 120 may be accommodated in the insulating bag 124 and disposed inside the housing 110.

[0066] The electrode assembly 120 may include a positive electrode 121. The positive electrode 121 may include a positive electrode current collector and a positive electrode active material. In some embodiments, the positive electrode current collector may include aluminum, aluminum alloy, etc., and the positive electrode active material may include lithium cobalt oxide, lithium manganese oxide, lithium nickel oxide, lithium iron phosphate, etc. The positive electrode active material may be coated on the surface of the positive electrode current collector. A part of the positive electrode current collector not coated with the positive electrode active material may be used as the positive electrode terminal 121a. In some embodiments, a plurality of positive electrode terminals 121a may be provided, and some or all of the plurality of positive electrode terminals 121a may be connected to each other.

[0067] The electrode assembly 120 may include a negative electrode 122. The negative electrode 122 may include a negative electrode current collector and a negative electrode active material. In some embodiments, the negative electrode current collector may include copper, copper alloy, nickel, nickel alloy, etc., and the negative electrode active material may include carbon, silicon, etc. The negative electrode active material may be coated on the surface of the negative electrode current collector. A part of the negative electrode current collector not coated with the negative electrode active material may be used as the negative electrode terminal 122a. In some embodiments, a plurality of negative electrode terminals 122a may be provided, and some or all of the plurality of negative electrode terminals 122a may be connected to each other.

[0068] The electrode assembly 120 may include a separator 123. The separator 123 may be disposed between the positive electrode 121 and the negative electrode 122. The separator 123 may function to limit physical contact between the positive electrode 121 and the negative electrode 122 and provide a channel for ion movement. In some embodiments, the separator 123 may be made of a polymer material including polyethylene, polypropylene, etc. Additionally, the separator 123 may include a dry separator and a wet separator. In some embodiments, the separator 123 may include a coating, and the coating includes a ceramic coating, etc.

[0069] The electrode assembly 120 may be formed by arranging the above components in a winding, stacking, etc. manner. For example, the electrode assembly 120 may be formed in a structure where the positive electrode 121, the negative electrode 122, and the separator 123 are wound around a longitudinal axis or a transverse axis. Or, the electrode assembly 120 may be formed in a structure where the above winding structure is compressed in a direction substantially perpendicular to the winding axis. The winding structure may be referred to as a "jelly roll" etc. in the art.

[0070] As another example, the electrode assembly 120 may be formed in a structure in which the positive electrode 121, the negative electrode 122, and the separator 123 are sequentially stacked in the vertical direction (e.g., in the thickness direction or the height direction of the electrode assembly). In some cases, in the stacking structure, the separator 123 may be formed in a structure in which a plurality of unit separators 123 continuous in the length direction are sequentially folded and stacked in accordance with the stacking order of the positive electrode 121 and the negative electrode 122. The stacking structure may be referred to as "stack and folding", "z-folding", etc. in the art. However, in this embodiment, the arrangement of each component of the electrode assembly 120 is not particularly limited. The electrode assembly 120 may have various arrangements other than the above examples.

[0071] In some embodiments, the electrode assembly 120 may be composed of a plurality of unit cells combined. For example, the electrode assembly 120 may include unit cells wound in a jelly roll manner, and two or more of the unit cells may be combined to form the electrode assembly 120. In this embodiment, the electrode assembly 120 is formed by combining two unit cells. As another example, the electrode assembly 120 may include unit cells wound in a stack and fold manner, and two or more of the unit cells may be combined to form the electrode assembly 120.

[0072] The electrode assembly 120 may be accommodated in the internal space of the housing 110 together with the electrolyte. In some embodiments, the electrolyte may be formed of an organic solvent containing a lithium salt. For example, the lithium salt may include liquid or gel-like lithium hexafluorophosphate (LiPF6), lithium tetrafluoroborate (LiBF4), etc., and the organic solvent may include cyclic carbonates such as ethylene carbonate (EC), propylene carbonate (PC), and linear carbonates such as diethyl carbonate (DEC), dimethyl carbonate (DMC), and ethyl methyl carbonate (EMC).

[0073] In some other embodiments, the electrolyte may be omitted or replaced. For example, when an inorganic solid electrolyte is used, the liquid or gel-like electrolyte may be omitted.

[0074] On the other hand, the secondary battery 100 according to this embodiment may include a cover plate 130.

[0075] The cover plate 130 may close the opening 111. In this embodiment, the cover plate 130 is shown in a quadrilateral plate shape corresponding to the opening 111. The cover plate 130 may be coupled to the housing 110 to seal the internal space of the housing 110 in which the electrode assembly 120 is provided. In some embodiments, the cover plate 130 may be joined to the housing 110 by welding such as ultrasonic welding, laser welding, etc.

[0076] The positive terminal 131 and the negative terminal 132 can be provided on the cover plate 130. The positive terminal 131 can be electrically connected to the positive electrode joint 121a of the electrode assembly 120, and the negative terminal 132 can be electrically connected to the negative electrode joint 122a of the electrode assembly 120.

[0077] The cover plate 130 can include an exhaust port (vent) 133. In this embodiment, the exhaust port 133 is provided between the positive terminal 131 and the negative terminal 132. However, the position of the exhaust port 133 can vary in various ways according to needs and is not necessarily limited to the illustrated example. In some other embodiments, the exhaust port 133 can be provided in the housing 100 or added to the housing 110. The exhaust port 133 can be opened according to the internal pressure of the housing 110. The exhaust port 133 can function to discharge the internal pressure to the outside of the housing 110, thereby helping to stabilize the internal components of the housing 110. The exhaust port 133 can include a notch having a predetermined shape. The notch can be induced to break according to the internal pressure, thereby partially opening the internal space of the housing 110.

[0078] The cover plate 130 can include an electrolyte injection port 134. The electrolyte injection port 134 can be used to inject electrolyte into the internal space of the housing 110. In this embodiment, the electrolyte injection port 134 is provided adjacent to the exhaust port 133 in the central region of the cover plate 130. However, the position of the electrolyte injection port 134 can vary in various ways and is not necessarily limited to the illustrated example. The electrolyte injection port 134 can be appropriately sealed after processes such as electrolyte injection and formation. In some embodiments, the electrolyte injection port 134 can be sealed by pressing in a spherical sealing member made of a polymer resin.

[0079] The structure of the electrode assembly 120 shown in the present disclosure is exemplary. In the present disclosure, the electrode assembly 120 is shown as including the positive electrode joint 121a and the negative electrode joint 122a arranged side by side from one side of the electrode assembly 120, but the positions and / or the number of the positive electrode joint 121a and the negative electrode joint 122a are exemplary. For example, in an embodiment not shown, the positive electrode joint 121a and the negative electrode joint 122a can be provided with the electrode assembly 120 (e.g., the positive electrode material 121, the negative electrode material 122, and the separator 123) therebetween. At least a part of the positive electrode joint 121a and the negative electrode joint 122a can be respectively located between the housing 110 and the electrode assembly 120.

[0080] In the present disclosure, a secondary battery 100 including a case 110 and a cover plate 130 is shown. The case 110 includes an opening 111, and the cover plate 130 is located on one side of the case 110, but this is merely exemplary. For example, in an embodiment not shown, a secondary battery 100 including a plurality of cover plates 130 located on both sides of the case 110 may be provided. At least one of the plurality of cover plates 130 may include a bonding area described below.

[0081] A secondary battery 100 according to an embodiment of the present disclosure may include a bonding structure between the cover plate 130 and the case 110 as a technical feature. Therefore, the bonding structure between the cover plate 130 and the case 110 will be described in more detail below. For convenience, hereinafter, new reference numerals will be given to the cover plate and the case according to each embodiment and described.

[0082] Figure 2a is a schematic perspective view of a cover plate and a case according to an embodiment. Figure 2b is Figure 2a a schematic partial cross-sectional view of the shown cover plate and case.

[0083] Referring to Figure 2a and Figure 2b , the case 210 of the present embodiment may be generally in a rectangular parallelepiped shape, and an opening 211 may be formed at the upper end of the case 210. The opening 211 may provide a passage for inserting an electrode assembly (e.g., Figure 1c the electrode assembly 120). The opening 211 may be appropriately closed by a cover plate 220 to be described later. Figure 1a , Figure 1b and / or Figure 1c at least a part of the description of the case 110 and the cover plate 130 of Figure 2a , Figure 2b and / or Figure 2c the case 210 and the cover plate 220.

[0084] The case 210 may include an inner side surface 212 and an outer side surface 213. The inner side surface 212 may be disposed toward the inside of the case 210, and the outer side surface 213 may be disposed correspondingly toward the outside of the case 210. The case 210 may have a predetermined thickness between the inner side surface 212 and the outer side surface 213.

[0085] An insulating coating 212a may be included on the inner side surface 212 of the housing 210. The insulating coating 212a may be formed in a predetermined area of the inner side surface 212. In the present embodiment, the insulating coating 212a may be appropriately omitted in a part of the upper end area 212b of the inner side surface 212. That is, the insulating coating 212a may be appropriately omitted in a part of the upper end area 212b including the joint portion of the cover plate 220 to be described later. This can prevent damage to the insulating coating 212a due to physical contact of the cover plate 220, welding heat, etc.

[0086] On the other hand, the cover plate 220 of the present embodiment may be fastened to the upper end of the housing 210 to close the opening 211. The cover plate 220 may be formed in a plate shape having a predetermined left - right and front - back length to appropriately close the opening 211. In the present embodiment, the cover plate 220 may be joined to the housing 210 by welding the edge portion to the upper end of the housing 210. That is, the cover plate 220 may be welded and joined to the housing 210.

[0087] The cover plate 220 may include a joint area 221 that is welded to the housing 210. In the present embodiment, the joint area 221 extends along the edge portion of the cover plate 220. However, the position, range, etc. of the joint area 221 may vary as needed and are not necessarily limited to the illustrated example. For example, in some embodiments, the joint area 221 may extend limitedly along a part of the edge of the cover plate 220, and for the remaining part of the edge, other alternative joining methods may be considered.

[0088] In the present embodiment, the joint area 221 may include more than one support surface 222. The support surface 222 may contact and be supported by the inner side surface 212 of the housing 210, whereby at least a part of the joint area 221 may be spaced apart from the inner side surface 212 of the housing 210 by a predetermined distance. That is, a chamber 223 to be described later may be formed between the joint area 221 and the inner side surface 212.

[0089] In some embodiments, a plurality of support surfaces 222 may be formed, and the plurality of support surfaces 222 may be arranged at a predetermined interval along the inner side surface 212 of the housing 210. In the present embodiment, three support surfaces 222 are shown, and the three support surfaces 222 are arranged vertically spaced apart along the inner side surface 212 of the housing 210. However, the number, arrangement, etc. of the support surfaces 222 may be changed as needed and are not necessarily limited to the illustrated example. For example, in some embodiments, the support surfaces 222 may be 2 to 5, and the 2 to 5 support surfaces 222 may be arranged spaced apart in a horizontal or inclined direction.

[0090] On the other hand, the bonding region 221 may include more than one chamber 223. The chambers 223 may be provided between a pair of adjacent support surfaces 222. That is, the chambers 223 may be formed between a pair of support surfaces 222 that are spaced apart from each other. The chambers 223 may be formed by separating a predetermined distance between the edge portion of the cover plate 220 and the inner side surface 212 of the housing 210.

[0091] In some embodiments, a plurality of chambers 223 may be formed, and the plurality of chambers 223 may be spaced apart from each other at a predetermined interval along the inner side surface 212 of the housing 210. In this embodiment, three chambers 223 are formed corresponding to the support surfaces 222, and the three chambers 223 are spaced apart vertically along the inner side surface 212 of the housing 210. However, similar to the support surfaces 222, the number, arrangement, etc. of the chambers 223 may be changed as needed and are not necessarily limited to the illustrated examples.

[0092] On the other hand, one or more of the chambers 223 or the plurality of chambers 223 may be arranged to be connected to the bonding line where the cover plate 220 and the housing 210 are bonded. That is, one or more of the chambers 223 or the plurality of chambers 223 may be arranged to be connected to the portion where the solder ball W is formed. In this embodiment, the uppermost chamber 223 among the three chambers 223 is arranged to be connected to the solder ball forming portion. In this case, the uppermost chamber 223 may function to accommodate by-products such as spatter and fume generated during welding to prevent the by-products from flowing into the interior of the housing 210.

[0093] On the other hand, the support surfaces 222 and the chambers 223 as described above may be arranged corresponding to an upper part region 212b of the housing 210. That is, the support surfaces 222 and the chambers 223 may be arranged in an upper part region 212b where the insulating coating 212a is omitted, and may be in contact with or spaced apart from the inner side surface 212 of the housing 210. Therefore, the support surfaces 222 and the chambers 223 may be used as a structure for ensuring the distance between the solder ball W and the insulating coating 212a and restricting the heat transfer during welding.

[0094] On the other hand, in this embodiment, the support surfaces 222 and the chambers 223 as described above may be formed by a first extension rib 224 and a second extension rib 225. The first extension rib 224 may be formed to extend upward from the edge portion of the cover plate 220, and the second extension rib 225 may be formed to extend laterally from the upper end of the first extension rib 224 toward the outer side surface 213 of the housing 210. In this embodiment, the bonding region 221 may be joined to the housing 210 by welding the end portion of the second extension rib 225 to the upper end of the housing 210.

[0095] The first extension rib 224 can extend vertically for a predetermined length to correspond to a part of the upper end region 212b of the omitted insulating coating 212a. Additionally, the first extension rib 224 can be spaced apart from the inner side surface 212 of the housing 210 by a predetermined distance. The spacing between the first extension rib 224 and the inner side surface 212 can be used as the chamber 223 described above.

[0096] In this embodiment, the first extension rib 224 can be provided with a plurality of support ribs 226. The support ribs 226 can be formed to extend laterally from the first extension rib 224 toward the inner side surface 212 of the housing 210. The ends of the support ribs 226 can contact and be supported by the inner side surface 212 of the housing 210 to form a support surface 222. Additionally, a plurality of support ribs 226 can be provided, and the plurality of support ribs 226 can be spaced apart vertically by a predetermined distance along the first extension rib 224 extending vertically. The spaces between the support ribs 226 can be used as the chamber 223 described above. In this embodiment, three support ribs 226 are spaced apart vertically, and three chambers 223 are formed between the second extension rib 225 and the three support ribs 226.

[0097] Although not shown, in some other embodiments, some or all of the plurality of support ribs 226 described above can have different sizes, shapes, arrangements, etc. For example, the plurality of support ribs 226 can be formed with different thicknesses or spacings such that the respective chambers 223 have different volumes. More specifically, the plurality of support ribs 226 can be arranged such that their spacing gradually decreases or increases toward the lower side. Alternatively, the plurality of support ribs 226 can be formed such that their thickness gradually decreases or increases toward the lower side. As another example, the lateral lengths of the plurality of support ribs 226 can be different. More specifically, the plurality of support ribs 226 can be formed such that their lateral lengths gradually decrease or increase toward the lower side. In this case, at least a part of the support surfaces 222 of the respective support ribs 226 can contact the inner side surface 212 of the housing 210 with different pressing forces, and in some cases, a part of the support surfaces 222 can be arranged to be spaced apart from the inner side surface 212 by a predetermined degree.

[0098] Figure 2c is Figure 2a the operating state diagram of the shown cover plate and the housing. For example, Figure 2c the (a) of Figure 2c is a diagram for explaining the bonding process of the cover plate 220 and the housing 210.

[0099] Referring to Figure 2cIn (a) thereof, after the electrode assembly 120 and the like are provided, the cover plate 220 can be fastened to the upper end of the housing 210 to close the opening 211 at the upper end of the housing 210. In this embodiment, the cover plate 220 can be inserted and fastened to the opening 211 at the upper end of the housing 210 by making the engagement area 221 formed at the edge portion of the cover plate 220 contact and slide along the inner side surface 212 of the housing 210. In addition, the second extension rib 225 contacts and is supported by the upper end of the housing 210, so that the up-and-down position of the cover plate 220 can be restricted.

[0100] The cover plate 220 can be inserted into the opening 211 as described above and then welded to the housing 210. Specifically, in this embodiment, the second extension rib 225 of the cover plate 220 and the upper end of the housing 210 can form a weld bead W and be joined. Here, the chamber 223 provided at the uppermost end is connected to the bonding wire and can accommodate by-products such as spatter and fume generated during welding. Therefore, the inflow of welding by-products into the interior of the housing 210 can be appropriately restricted.

[0101] On the other hand, in this embodiment, the bonding wire forming the weld bead W can be spaced upward from the insulating coating 212a by a predetermined distance through the first extension rib 224 extending vertically. In addition, between the bonding wire and the insulating coating 212a, a plurality of chambers 223 are provided vertically, and the plurality of chambers 223 are separated from each other by the support ribs 226. The plurality of chambers 223 and the support ribs 226 as described above can function to restrict the welding heat generated in the bonding wire from being transferred to the insulating coating 212a. As shown in the figure, the structure in which the plurality of chambers 223 and the support ribs 226 are alternately and repeatedly provided can contribute to more effectively restricting the transfer of the welding heat as described above. Therefore, the damage to the insulating coating 212a during welding bonding can be greatly reduced.

[0102] Referring to Figure 2c In (b) thereof, the engagement area 221 as described above can also contribute to maintaining the sealing force of the cover plate 220 during inflation. That is, the plurality of support ribs 226 and the support surface 222 provided with a vertical space therebetween through the chamber 223 can form a kind of multi-layer sealing structure in the area adjacent to the weld bead W, and this multi-layer sealing structure can function to maintain the sealed state when the housing 210 is deformed. For example, according to the deformation form of the housing 210, even if a part of the support ribs 226 and the support surface 222 are spaced apart from the inner side surface 212, other part of the support ribs 226 and the support surface 222 can remain in contact with the inner side surface 212, so that the sealed state can be maintained.

[0103] In addition, as described above, the chamber 223 can also be used as a kind of buffer space for temporarily accommodating heat, pressure, by-products, etc. inside the housing 210. When a plurality of chambers 223 are provided as in this embodiment, the function as a buffer space as described above can be more effectively realized.

[0104] Figure 3a is a schematic perspective view of a cover plate and a housing according to another embodiment. Figure 3b is Figure 3a a schematic partial cross-sectional view of the cover plate and the housing shown. Regarding Figure 2a 、 Figure 2b and / or Figure 2c at least a part of the description of the housing 210 and the cover plate 220 may be applicable to Figure 3a and / or Figure 3b the housing 310 and the cover plate 320.

[0105] For convenience, the following embodiments will focus on the differences from the above embodiments.

[0106] Referring to Figure 3a and Figure 3b in this embodiment, an opening 311 may be formed at the upper end of the housing 310, and the housing 310 may include an inner side surface 312 and an outer side surface 313. In addition, an insulating coating 312a may be formed on the inner side surface 312 of the housing 310. This is generally similar to the above embodiment.

[0107] On the other hand, the cover plate 320 of this embodiment may be fastened to the upper end of the housing 310 to close the opening 311. The cover plate 320 may include a bonding area 321 welded to the housing 310, and the bonding area 321 may extend along the edge portion of the cover plate 320.

[0108] The bonding area 321 may include a first extension rib 324 and a second extension rib 325. The first extension rib 324 may be formed to extend upward from the edge portion of the cover plate 320. The second extension rib 325 may be formed to extend laterally from the upper end of the first extension rib 324 toward the outer side surface 313 of the housing 310.

[0109] The bonding area 321 may include a plurality of chambers 323. In this embodiment, three chambers 323 are shown spaced apart vertically. In this embodiment, a groove may be formed on the outer surface of the first extension rib 324 facing the inner side surface 312 of the housing 310, and such a groove may form the chamber 323. That is, the chamber 323 of this embodiment may have a form of a groove formed by recessing the outer surface of the first extension rib 324 by a predetermined degree.

[0110] In addition, in the present embodiment, the uppermost chamber 323 may be arranged to correspond to the upper edge portion of the housing 310. That is, the uppermost chamber 323 extends to a height that is a predetermined degree higher than the upper end of the housing 310, so that the upper edge portion of the housing 310 can be exposed within the chamber 323. In other words, the uppermost chamber 323 may be provided at a height that includes the bonding wire forming the solder ball W therein. In this case, the by-products generated during welding can be more directly collected into the uppermost chamber 323.

[0111] On the other hand, the bonding region 321 may include a plurality of support surfaces 322. In the present embodiment, the outer surface of the first extension rib 324 between the pair of chambers 323 formed in the form of grooves may be used as the support surface 322. The support surface 322 and the chamber 323 as described above can limit the transfer of welding heat and contribute to maintaining the sealed state when the housing 310 is deformed due to gas expansion or the like. This is generally similar to the above-described embodiment.

[0112] As required, the cover plate 320 of the present embodiment may be provided with a chamfer 327 at the lower end edge corresponding to the bonding region 321. The chamfer 327 may extend downwardly and obliquely toward the inside of the housing 310 to guide the setting for the combination between the cover plate 320 and the housing 310.

[0113] Figure 4a is a schematic perspective view of a cover plate and a housing according to another embodiment. Figure 4b is Figure 4a the schematic partial cross-sectional view of the cover plate and the housing shown.

[0114] Referring to Figures 4a to 4b , the housing 410 of the present embodiment may include an opening 411, an inner side surface 412, and an outer side surface 413, and an insulating coating 412a may be formed on the inner side surface 412. This is generally similar to the above-described embodiment. Regarding Figure 2a , Figure 2b and Figure 2c of the housing 210 and the cover plate 220 and Figure 3a and Figure 3b of the housing 310 and the cover plate 320, at least a part of the description may be applicable to Figure 4a and / or Figure 4b of the housing 410 and the cover plate 420. For example, in an embodiment not shown, Figure 4a and Figure 4b of the cover plate 420 may include Figure 3a or Figure 3b of the chamfer 327.

[0115] The cover plate 420 of this embodiment can be fastened to the upper end of the housing 410 to close the opening 411. The cover plate 420 may include a bonding area 421 welded to the housing 410, and the bonding area 421 may extend along the edge portion of the cover plate 420.

[0116] In addition, the bonding area 421 may include a first extension rib 424 and a second extension rib 425. In this embodiment, the first extension rib 424 may be formed by bending a predetermined amount from the edge portion of the cover plate 420 and extending upward. The second extension rib 425 may extend laterally from the upper end of the first extension rib 424 and be welded to the upper end of the housing 410.

[0117] The bonding area 421 may include a plurality of chambers 423 and a support surface 422. In this embodiment, two chambers 423 and two support surfaces 422 are respectively shown. One or more of the plurality of chambers 423 may be arranged to be connected to a bonding wire forming a solder ball W, and in this embodiment, the uppermost chamber 423 is arranged to be connected to the bonding wire.

[0118] On the other hand, in this embodiment, the plurality of chambers 423 and the support surface 422 may be formed by the bending of the first extension rib 424. The first extension rib 424 may be formed by repeatedly bending inward and outward in a region adjacent to the inner side surface 412 of the housing 410 and extending upward, and a partial region of the first extension rib 424 that contacts and is supported by the inner side surface 412 may be used as the support surface 422. In addition, the spaced-apart space between the first extension rib 424 and the inner side surface 412 may be used as the above-described chamber 423. In this embodiment, the chambers 423 and the support surface 422 are alternately arranged repeatedly according to the bending of the first extension rib 424.

[0119] The functions of the plurality of chambers 423 and the support surface 422 as described above may be similar to the functions of the corresponding structures of the above embodiment. That is, the uppermost chamber 423 may function to accommodate by-products such as spatter and soot generated during welding to prevent the by-products from flowing into the interior of the housing 410, and the plurality of chambers 423 and the support surface 422 that are alternately arranged repeatedly may function to limit the transfer of welding heat to the insulating coating 412a.

[0120] In addition, when the housing 410 is deformed due to gas expansion or the like, the plurality of support surfaces 422 may contribute to effectively maintaining the sealing state with the inner side surface 412. In this embodiment, the plurality of support surfaces 422 may be formed by the bending of the first extension rib 424, and this bent shape may allow a certain amount of elastic deformation of each support surface 422, thereby contributing to improving the sealing force.

[0121] Figure 5a It is a schematic perspective view of a cover plate and a housing according to another embodiment. Figure 5b IsFigure 5a Schematic partial cross-sectional view of the cover plate and the housing shown.

[0122] Referring to Figure 5a and Figure 5b , the difference between this embodiment and the above embodiment is that the bonding region 521 extends laterally to correspond to the main surface of the cover plate 520. Additionally, in this embodiment, the upper end of the housing 510 can be laterally bent and extended by a predetermined degree to correspond to the bonding region 521. Regarding Figure 2a and Figure 4b , at least a part of the description of the housings 210, 310, 410 and the cover plates 220, 320, 420 can be applied to Figure 5a and / or Figure 5b the housing 510 and the cover plate 520.

[0123] Specifically, the housing 510 of this embodiment can include an opening 511, an inner side surface 512, and an outer side surface 513, and an insulating coating 512a can be formed on the inner side surface 512. In this embodiment, the insulating coating 512a can be formed in a predetermined region including the upper end region of the inner side surface 512. That is, in this embodiment, the welding position can be laterally spaced from the insulating coating 512a by a predetermined distance through a flange 514 to be described later. Therefore, different from the above embodiment, the insulating coating 512a can be not omitted in the upper end region of the inner side surface 512.

[0124] On the other hand, the upper end of the housing 510 of this embodiment can include a flange 514. The flange 514 can be formed by laterally extending a predetermined length from the upper end of the housing 510. In this embodiment, considering the insertion of the electrode assembly 120, the flange 514 extends from the upper end of the housing 510 to the outside of the housing 510. The flange 514 can be disposed corresponding to the bonding region 521 of the cover plate 520 to be welded to the bonding region 521.

[0125] On the other hand, the cover plate 520 can be fastened to the upper end of the housing 510 to close the opening 511. The cover plate 520 can include a bonding region 521 for bonding with the housing 510, and the bonding region 521 can extend along the edge portion of the cover plate 520.

[0126] In this embodiment, the bonding region 521 can extend laterally to correspond to the main surface of the cover plate 520. In other words, in this embodiment, the bonding region 521 can generally form a plane corresponding to the cover plate 520 and extend laterally. Or, in this embodiment, the bonding region 521 can be defined as a partial region of the edge of the cover plate 520 that is combined with the flange 514.

[0127] The bonding region 521 may include more than one chamber 523. In the present embodiment, the chamber 523 is formed by a groove recessed in the bottom surface of the bonding region 521 and the upper surface of the flange 514.

[0128] In some embodiments, a plurality of chambers 523 may be formed, and the plurality of chambers 523 may be spaced apart from each other at a predetermined interval in the bonding region 521. In the present embodiment, two chambers 523 are laterally spaced apart across the support surface 522. Additionally, in this case, more than one of the plurality of chambers 523 may be arranged to be connected to a bonding line that joins the flange 514 and the cover plate 520. That is, more than one of the plurality of chambers 523 may be arranged to be connected to the portion where the solder ball W is formed. In the present embodiment, the chamber 523 disposed on the outermost side (the right side in the figure) of the two chambers 523 is arranged to be connected to the solder ball W forming portion. In this case, the outermost chamber 523 may have similar functions and effects to those of the above-described embodiment.

[0129] On the other hand, the bonding region 521 may include more than one support surface 522 that contacts and is supported by the flange 514. When a plurality of chambers 523 are arranged as in the present embodiment, the support surface 522 may include a plurality of support surfaces, and the chambers 523 and the support surfaces 522 may be alternately arranged repeatedly in the lateral direction.

[0130] As described above, a secondary battery according to an embodiment of the present disclosure may include a cover plate that includes a bonding region and is welded to a case. Additionally, the bonding region may include: a support surface that contacts and is supported by the case; and a chamber that is formed between the bonding region and the case. In some embodiments, a plurality of the above-described support surfaces and chambers may be provided respectively, and the plurality of support surfaces and chambers may be alternately arranged repeatedly within the bonding region.

[0131] The bonding region as described above can accommodate by-products generated during welding and limit the transfer of welding heat to the insulation coating inside the case. Therefore, the inflow of welding by-products or damage to the insulation coating can be prevented during the manufacturing process. Additionally, the bonding region as described above can effectively cope with deformation of the case caused by gas expansion or the like. That is, even when the case is deformed, the bonding region as described above can maintain a sealed state through a plurality of support surfaces. Additionally, each chamber serves as a buffer space for temporarily accommodating heat, pressure, by-products, etc. inside, thereby assisting in maintaining the above-described sealed state.

[0132] Although the embodiments of the present disclosure have been described above, those skilled in the art can make various modifications or changes to the present disclosure by adding, changing, deleting, or adding components without departing from the technical idea of the present disclosure described in the claims, and this will also be included within the scope of the claims of the present disclosure.

Claims

1. A secondary battery comprising: Electrode assembly; a housing including an opening for inserting the electrode assembly; as well as a cover plate, comprising a joint area welded to the housing, and the cover plate closes the opening, The joining area includes: One or more supporting surfaces, contacting with and supported by the shell; as well as One or more chambers are formed by a portion of the engagement area being separated from the housing by the support surface.

2. The secondary battery according to claim 1, wherein The chamber is configured to be connected to a weld bead forming portion for joining with the shell to contain byproducts generated during welding.

3. The secondary battery according to claim 1, wherein The chamber includes a plurality of chambers, the plurality of chambers are spaced apart from each other across the support surface, and at least one of the plurality of chambers is connected to a weld bead forming portion for joining with the housing.

4. The secondary battery according to claim 1, wherein The inner side of the housing includes an insulating coating, The cover plate includes a welding bead engaged with the housing, The support surface and the chamber are disposed between the weld bead and the insulating coating.

5. The secondary battery according to claim 1, wherein The support surface includes a plurality of support surfaces, and the chamber includes a plurality of chambers. The plurality of support surfaces and the plurality of chambers are repeatedly and alternately arranged along the joining area.

6. The secondary battery according to claim 1, wherein The support surface includes a plurality of support surfaces, and the plurality of support surfaces are configured such that when the shell is deformed, at least one of the plurality of support surfaces maintains a contact state with an inner side surface of the shell.

7. The secondary battery according to claim 1, wherein The joining area comprises: a first extension rib extending upward from an edge of the cover plate, wherein at least a portion of the first extension rib is separated from an inner side surface of the housing by the support surface; and A second extension rib is formed to extend laterally from the first extension rib to form a welding bead for engaging the housing.

8. The secondary battery according to claim 7, wherein The first extension ribs include more than one supporting ribs, the supporting ribs are extended toward the inner side surface of the shell, and ends of the supporting ribs are in contact with the inner side surface of the shell and supported to form the supporting surface.

9. The secondary battery according to claim 8, wherein The supporting ribs include a plurality of supporting ribs, and the plurality of supporting ribs are spaced apart at predetermined intervals along the first extending rib to form the chamber between a pair of adjacent supporting ribs.

10. The secondary battery according to claim 7, wherein The cover plate includes a chamfer formed at a lower end edge portion corresponding to the joining area to guide the combination with the housing.

11. The secondary battery according to claim 1, wherein The joint area includes a first extension rib, and the first extension rib is formed by extending upward from the edge of the cover plate. The first extension rib repeatedly bends inward and outward and extends toward the inner side surface of the shell, and through the bending, a portion of the first extension rib contacts the inner side surface of the shell to form the supporting surface, and another portion of the first extension rib is separated from the inner side surface of the shell to form the chamber.

12. The secondary battery according to claim 1, wherein The housing includes a flange extending laterally from an upper end of the housing toward an outer side of the housing to engage with the cover plate. The joint area forms a plane corresponding to the cover plate and extends transversely.

13. The secondary battery according to claim 12, wherein: The chamber is formed in the form of a groove recessed from the bottom surface of the joining area, and a plurality of the chambers are arranged laterally spaced apart along the joining area. At least one of the plurality of chambers is connected to a weld bead forming portion for joining with the shell.

14. The secondary battery according to claim 12, wherein The support surface and the cavity are disposed between an insulating coating formed on an inner side surface of the housing and a welding bead for joining the cover plate and the housing to limit welding heat transfer to the insulating coating.

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