Cover assembly and secondary battery including same

Abstract

Disclosed are a cap assembly and a secondary battery including the same. The cover assembly comprises: a cover plate having a first through hole; and the insulating plate is arranged below the cover plate, the insulating plate is provided with a second through hole aligned with the first through hole, and the insulating plate comprises a main body part with the second through hole, a side wall extending upwards along the edge of the main body part and a bent part connecting the main body part and the side wall.

Description

TECHNICAL FIELD

[0001] Embodiments relate to a cover assembly and a secondary battery including the same. BACKGROUND

[0002] Secondary batteries are rechargeable batteries that can be charged and discharged multiple times. These secondary batteries are commonly employed in various applications, including electronic devices (e.g., smartphones, laptops, tablets, etc.), electric vehicles, solar power generation systems, and emergency power supplies. In particular, lithium ion batteries are widely used in various electronic devices and electric vehicles due to their high energy density and excellent charging / discharging efficiency.

[0003] Secondary batteries can be classified into cylindrical secondary batteries, prismatic secondary batteries, and pouch-type secondary batteries according to the shape of their housings. Prismatic secondary batteries have a structure in which an electrode assembly is accommodated in a prismatic metal can. The electrode assembly is inserted into the prismatic metal can and the can is sealed by a welding cover plate.

[0004] The above information disclosed in this Background section is only for enhancing the understanding of the background of the present disclosure, and therefore, it can contain information that does not constitute the related art (or prior art). SUMMARY

[0005] However, the technical problems to be solved by the present disclosure are not limited to the above problems, and the person skilled in the art will clearly understand other problems not mentioned herein and aspects and features of the present disclosure that will solve such problems from the following description of the present disclosure.

[0006] Embodiments include a cover assembly including a cover plate having a first through-hole, and an insulating plate under the cover plate, the insulating plate having a second through-hole aligned with the first through-hole, wherein the insulating plate includes a main body portion having the second through-hole, a side wall extending upward along an edge of the main body portion, and a curved portion connecting the main body portion and the side wall.

[0007] The cover plate can include a groove on a lower surface thereof, and the groove can be between the first through-hole and an edge of the cover plate.

[0008] The groove can include a first groove and a second groove along a longitudinal direction of the first through-hole, the welding portion can extend on the edge of the cover plate in a longitudinal direction of the cover plate, and each of the first groove and the second groove is in an area between the first through-hole and the welding portion.

[0009] In a short side direction of the cover plate, the groove can at least partially overlap the first through-hole.

[0010] A center of the groove and a center of the first through-hole can be aligned on a same straight line in the short side direction of the cover plate.

[0011] The cover assembly can further include a stepped portion at an outer side of the curved portion of the insulation plate.

[0012] The stepped portion can at least partially overlap the second through-hole in a short side direction of the insulation plate.

[0013] A center of the stepped portion and a center of the second through-hole can be aligned on a same line in the short side direction of the insulation plate.

[0014] The curved portion can include a first curved surface on an inner surface of the insulation plate, and a second curved surface offset from the first curved surface by a thickness of the insulation plate, the second curved surface being on the stepped portion.

[0015] The curved portion can further include a third curved surface on an outermost surface of the insulation plate.

[0016] A radius of curvature of the first curved surface can be equal to or greater than 0.5 mm.

[0017] A radius of curvature of each of the second curved surface and the third curved surface can be equal to or greater than 2 mm.

[0018] The insulation plate can further include a rib connecting the main body portion and the sidewall.

[0019] Embodiments include a secondary battery including: an electrode assembly including a first electrode plate, a second electrode plate, and a separator; a case accommodating the electrode assembly, the case having an open end; a cover plate coupled to the open end of the case, the cover plate including a first through-hole; and an insulation plate under the cover plate, the insulation plate including a second through-hole aligned with the first through-hole, wherein the insulation plate includes a main body portion having the second through-hole, a sidewall extending upward along an edge of the main body portion, and a curved portion connecting the main body portion and the sidewall, and wherein the curved portion has a radius of curvature.

[0020] The cover plate can further include a groove on a lower surface of the cover plate, and the groove can be between the first through-hole and an edge of the cover plate.

[0021] The groove can include a first groove and a second groove, the first groove and the second groove can be along a longitudinal direction of the first through-hole, the welding portion can extend on the edge of the cover plate in a longitudinal direction of the cover plate, and each of the first groove and the second groove can be in an area between the first through-hole and the welding portion.

[0022] The stepped portion can be at an outer side of the curved portion of the insulation plate, and the stepped portion can at least partially overlap the second through-hole in a short side direction of the insulation plate.

[0023] The curved portion can include a first curved surface on an inner surface of the insulation plate, a second curved surface offset from the first curved surface by a thickness of the insulation plate, the second curved surface being on the stepped portion, and a third curved surface on an outermost surface of the insulation plate.

[0024] A radius of curvature of the first curved surface can be equal to or greater than 0.5 mm.

[0025] A radius of curvature of each of the second curved surface and the third curved surface can be equal to or greater than 2 mm.

[0026] However, aspects and features of the present disclosure are not limited to the above-described aspects and features, and other aspects and features not mentioned will be clearly understood by those skilled in the art through the detailed description described below. BRIEF DESCRIPTION OF DRAWINGS

[0027] The following accompanying drawings, attached to the specification, illustrate embodiments of the present disclosure and, together with the detailed description below, further describe aspects and features of the present disclosure. Accordingly, the present disclosure should not be construed as being limited to the accompanying drawings:

[0028] Figure 1 is a perspective view illustrating an example of a battery cell according to one or more embodiments of the present disclosure.

[0029] Figure 2 is a perspective view illustrating another example of a battery cell according to one or more embodiments of the present disclosure.

[0030] Figure 3 is an exploded perspective view of an example of a cover assembly according to one or more embodiments of the present disclosure.

[0031] Figure 4A and Figure 4B illustrates an example of a lower surface of a cover plate according to one or more embodiments of the present disclosure.

[0032] Figure 5 is a bottom view illustrating an example of a lower surface of a cover plate of Figure 4B

[0033] Figure 6 is a cross-sectional view taken along line A-A' of Figure 3

[0034] Figure 7 illustrates an example in which a groove causes the cover plate to bend upward according to one or more embodiments of the present disclosure.

[0035] Figure 8A and Figure 8B illustrates an example of an insulation plate according to one or more embodiments of the present disclosure.

[0036] ​​Figure 9 FIG. 11 illustrates an example of a lower surface of an insulation panel according to one or more embodiments of the present disclosure. DETAILED DESCRIPTION

[0037] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. The terms or words used in the present specification and claims should not be interpreted as being generally or dictionary meanings, but should be interpreted based on the idea of the inventor to best describe his / her own invention, based on the principle that an inventor can properly define the concept of the terms to best describe his / her own invention within a range of equivalency of the technical idea. Accordingly, the embodiment described in the present specification and illustrated in the accompanying drawings is merely an example, and the technical idea of the present disclosure should not be interpreted as being limited to only the described embodiment.

[0038] The embodiments described in the present specification and the configurations illustrated in the accompanying drawings are merely some embodiments of the present disclosure, and do not represent all technical spirits, aspects, and features of the present disclosure. Accordingly, it should be understood that there can be various equivalents or modifications of the embodiments described herein at the time of filing the present application.

[0039] It should be understood that when an element or layer is referred to as being "on", "connected to", or "coupled to" another element or layer, it can be directly on, directly connected to, or directly coupled to the other element or layer, or one or more intervening elements or layers can also be present. In contrast, when an element or layer is referred to as being "directly on", "directly connected to", or "directly coupled to" another element or layer, there are no intervening elements or layers present. By the term "and / or" it is meant one or all of the listed terms. For example, when a first element is described as "coupled" or "connected" to a second element, the first element can be directly coupled or connected to the second element, or intervening elements can be present. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0040] In the figures, the dimensions of various elements, layers, etc., may be enlarged for clarity. The same reference numerals label the same elements. As used herein, the term “and / or” includes any and all combinations of one or more of the associated enumerated items. Furthermore, in describing embodiments of this disclosure, the use of “may” refers to “one or more embodiments of this disclosure.” When expressions such as “at least one of…” and “any one of…” precede / follow a list of elements, they modify the entire list of elements and not individual elements within the list. When a list of elements A, B, and C is labeled with phrases such as “at least one of A, B, and C,” “at least one of A, B, or C,” “at least one selected from the group of A, B, and C,” or “at least one selected from A, B, and C,” the phrase may refer to any and all suitable combinations or subsets of A, B, and C, such as A, B, C, A and B, A and C, B and C, or A and B and C. As used herein, the terms “use,” “utilization,” and variations thereof are to be considered synonymous with the terms “exploitation,” and variations thereof, respectively. As used herein, the terms “substantially,” “approximately,” and similar terms are used as approximate terms and not as terms of degree, and are intended to account for the inherent variations in measured or calculated values ​​that will be recognized by those skilled in the art.

[0041] It should be understood that although the terms first, second, third, etc., may be used herein to describe various elements, components, regions, layers, and / or portions, these elements, components, regions, layers, and / or portions should not be limited by these terms. These terms are used to distinguish one element, component, region, layer, or portion from another element, component, region, layer, or portion. Therefore, without departing from the teachings of the exemplary embodiments, the first element, first component, first region, first layer, or first portion discussed below may be referred to as a second element, second component, second region, second layer, or second portion.

[0042] For ease of description, spatial relative terms such as “below,” “under,” “down,” “above,” and “above” are used herein to describe the relationship between one element or feature and another illustrated in the figures. It should be understood that, in addition to the orientation depicted in the figures, the spatial relative terms are intended to also encompass different orientations of the device during use or operation. For example, if the device in the figures is flipped, an element described as “below” or “under” other elements or features will then be oriented “above” or “above” other elements or features. Therefore, the term “below” can encompass both above and below orientations. The device may be oriented in other ways (rotated 90 degrees or oriented in other directions), and the spatial relative descriptors used herein should be interpreted accordingly.

[0043] The terminology used herein is for the purpose of describing embodiments of this disclosure and is not intended to limit this disclosure. As used herein, unless the context clearly indicates otherwise, the singular forms “a” and “an” are intended to also include the plural forms. It should be further understood that when the term “comprising” and variations thereof are used in this specification, it specifies the presence of the described features, numbers, steps, operations, elements, and / or components, but does not exclude the presence or addition of one or more other features, numbers, steps, operations, elements, components, and / or groups thereof.

[0044] Furthermore, any numerical range disclosed and / or referenced herein is intended to include all subranges with the same numerical precision contained within the referenced range. For example, the range “1.0 to 10.0” is intended to include all subranges between (and inclusive of) the stated minimum value of 1.0 and the stated maximum value of 10.0, i.e., a minimum value equal to or greater than 1.0 and a maximum value equal to or less than 10.0, such as 2.4 to 7.6. Any maximum numerical limit set forth herein is intended to include all lower numerical limits contained herein, and all minimum numerical limits set forth herein are intended to include all higher numerical limits contained herein. Accordingly, the applicant reserves the right to amend this specification (including the claims) to expressly define any subranges contained within the range expressly set forth herein.

[0045] Referring to two compared elements, features, etc., as “identical” can mean that they are “substantially identical.” Therefore, the phrase “substantially identical” can include cases with deviations considered low in the art, such as 5% or less. Additionally, when a parameter is described as uniform over a given region, it can mean that it is uniform in terms of average value.

[0046] Throughout the manual, unless otherwise stated, each element may be singular or plural.

[0047] Placing any element "above (or below)" or "above (below)" another element can mean that the arbitrary element can be configured to contact the upper (or lower) surface of the element, and the other element can be located between the element and any element disposed on (or below) the element.

[0048] In addition, it should be understood that when a component is referred to as a “link,” “connect,” or “attached” to another component, these components can be directly “connected,” “linked,” or “attached” to each other, or another component can “intervene” between these components.

[0049] Throughout this specification, unless otherwise stated, when “A and / or B” is mentioned, it means A, B, or A and B. That is, “and / or” includes any or all combinations of the listed items. Unless otherwise stated, when “C-D” is mentioned, it means C and below. The terminology used in this specification is for describing embodiments of this disclosure and is not intended to limit this disclosure.

[0050] Figure 1 This is a perspective view illustrating an example of a battery cell 100 according to one or more embodiments of the present disclosure.

[0051] refer to Figure 1 The battery cell 100 may include: at least one electrode assembly wound or stacked with a separator (which is an insulator) inserted between the positive and negative electrodes; a housing 110 for housing the electrode assembly; and a cover plate 120 connected to the open end of the housing 110. Figure 1 The battery cell 100 shown can be a secondary battery type.

[0052] Each of the positive and negative electrodes may include a current collector made of a thin metal foil having a coated portion thereon coated with an active material and an uncoated portion thereon without the active material. The positive and negative electrodes are wound together after a separator (which is an insulator) is inserted between them. However, this disclosure is not limited thereto, and the electrode assembly may have a structure in which positive and negative electrodes, each made of multiple sheets, are alternately stacked with a separator inserted between them.

[0053] The housing 110 can form the overall appearance of the secondary battery and can be made of a conductive metal such as aluminum, aluminum alloy, or nickel-plated steel. In addition, the housing 110 can provide space therein to house the electrode assembly.

[0054] exist Figure 1 In the illustrated example, the casing 110 is a prismatic casing, and the battery cell 100 is a prismatic battery cell. The battery cell 100 can be any shape, such as prismatic, cylindrical, pouch-shaped, etc.

[0055] Each of the housing 110 and the cover 120 may be made of a conductive material. In one or more embodiments, the upper end of the housing 110 may be open, and the cover 120 may seal (e.g., be attached to) the open upper end of the housing 110.

[0056] The positive electrode terminal 130_1, which is electrically connected to the positive electrode, and the negative electrode terminal 130_2, which is electrically connected to the negative electrode, can be connected to the cover plate 120. For example, the positive electrode terminal 130_1 and the negative electrode terminal 130_2 can be mounted to protrude outward through the cover plate 120.

[0057] In one or more embodiments, the vent 140 may be formed on at least one surface of the battery cell 100. For example, in Figure 1 In the illustrated example, the vent 140 may be formed on the upper surface of the battery cell 100, i.e., on the cover 120. The vent 140 may be configured to open in response to the internal pressure in the battery cell 100 exceeding a predetermined threshold pressure.

[0058] In this case, the threshold pressure can be set differently depending on the battery's application, materials, uses, and other factors. For example, a relatively high threshold pressure can be set for batteries where the internal pressure of the casing 110 remains at a higher average pressure than in other applications due to short charge-discharge cycles during use. In another example, a relatively high threshold pressure can be set for batteries manufactured with materials and / or designs that have relatively high heat resistance and / or pressure resistance. In contrast, a relatively low threshold pressure can be set for batteries manufactured with materials and / or designs that have relatively low heat resistance and / or pressure resistance. Additionally, the vent 140 can be configured to open in response to the internal temperature exceeding a predetermined threshold temperature. With this configuration, the vent 140 can prevent the battery cell 100 from exploding or prevent a chain reaction of exothermic reactions in other battery cells located near the battery cell 100.

[0059] In one or more embodiments, the cover plate 120 may include an electrolyte injection hole 150. For example, the electrolyte injection hole 150 may be a through-hole formed through the cover plate 120 and may be configured such that electrolyte can be injected into the housing 110 after the cover plate 120 is coupled to and sealed to the open end of the housing 110. After the electrolyte is injected, the electrolyte injection hole 150 may be sealed with a sealing member.

[0060] Battery cell 100 can be a lithium (Li) battery cell, a sodium (Na) battery cell, etc. However, battery cell 100 can include any battery cell capable of repeatedly providing power through charging and discharging. In one or more embodiments, when battery cell 100 is a lithium battery cell, it can be used in electric vehicles (EVs) due to its superior lifespan and high-speed capability. For example, battery cell 100 can be used in hybrid electric vehicles such as plug-in hybrid electric vehicles (PHEVs). Additionally, lithium battery cells can be used in applications requiring large amounts of energy storage. For example, battery cell 100 can be used in electric bicycles, power tools, and similar applications.

[0061] Figure 2 This is a perspective view illustrating another example of a battery cell 200 according to one or more embodiments of the present disclosure.

[0062] Figure 2 The illustration shows a single 200mm battery cell. (Reference) Figure 2 The battery cell 200 may include a cover 220 configured to connect with an open end (e.g., an open upper end) of the housing, an insulating plate 260 disposed below the cover 220, and an electrode assembly 280 housed in the housing.

[0063] The cover plate 220 may include a first through hole 240 formed at a location corresponding to the exhaust component. The cover plate 220 may include a groove on its lower surface. The groove formed on the lower surface of the cover plate 220 may be configured to guide the cover plate 220 to bend upwards prior to the rupture of the exhaust component. (See reference...) Figure 4A and Figure 4B The structure of the groove on the lower surface of the cover plate 220 is discussed in detail.

[0064] The dimensions of the insulating plate 260 may correspond to the dimensions of the cover plate 220. In one or more embodiments, the insulating plate 260 may be a flat plate having an overall rectangular shape. The insulating plate 260 may have a second through hole formed at a location corresponding to (e.g., aligned with) the first through hole 240 in the cover plate 220. The insulating plate 260 may be configured to be in close contact with the lower surface of the cover plate 220. The insulating plate 260 may be used to insulate the cover plate 220 from the electrode assembly 280.

[0065] In the event of an impact to the secondary battery, the insulating plate 260 may crack, causing the electrode assembly to also crack. To prevent internal short circuits in the electrode assembly, the insulating plate 260 may include a curved portion formed at the edge of its lower surface. (See reference...) Figure 8A and Figure 8B The detailed structure of the curved portion formed in the insulating plate 260 is described in further detail.

[0066] Electrode assembly 280 can be housed within a housing. Electrode assembly 280 can be provided by winding or stacking a laminate comprising a first electrode plate (not shown), a diaphragm (not shown), and a second electrode plate (not shown), each formed as a sheet or film. In the case of a wound laminate, the winding axis can be parallel to the longitudinal direction of the housing. Alternatively, electrode assembly 280 can be stacked rather than wound, but the shape of electrode assembly 280 disclosed herein is not limited thereto. Additionally, electrode assembly 280 can be a Z-shaped stacked electrode assembly, wherein the positive electrode plate and negative electrode plate are bent into a Z-shape and stacked on opposite sides of the diaphragm. Furthermore, one or more electrode assemblies 280 can be stacked such that their long sides are adjacent to each other for housing within a housing. This disclosure is not intended to limit the number of electrode assemblies 280. In electrode assembly 280, the first electrode plate can act as a positive electrode, and the second electrode plate can act as a negative electrode. The reverse is also possible.

[0067] The first electrode plate can be formed by applying a first electrode active material (such as graphite or carbon) to a first electrode current collector formed of a metal foil such as copper (Cu), a Cu alloy, nickel (Ni), or a Ni alloy, and may include a first electrode tab (or a first uncoated portion), the first electrode tab being the area where the first electrode active material is not applied. The first electrode tab can be a path for current flow between the first electrode plate and the first terminal. In some examples, the first electrode tab can be formed by pre-cutting the first electrode plate such that, during the fabrication of the first electrode plate, the first electrode tab protrudes from a first side, and may protrude further from the first side than the diaphragm without further cutting.

[0068] The second electrode plate is formed by applying a second electrode active material (such as a transition metal oxide) to a second electrode current collector formed of a metal foil, such as Al or an Al alloy, and may include a second electrode tab (or a second uncoated portion), which is a region where the second electrode active material is not applied. The second electrode tab can be a path for current flow between the second electrode plate and the second terminal. In some examples, the second electrode tab can be formed by pre-cutting the second electrode plate such that, in the case of manufacturing the second electrode plate, the second electrode tab protrudes from a second side, and may protrude further from the second side than the diaphragm without further cutting.

[0069] Figure 3 This is an exploded perspective view of an example of a cover assembly according to one or more embodiments of the present disclosure.

[0070] The cover assembly may include a cover plate 320, a vent 340, and an insulating plate 360. The cover assembly may be coupled to a housing. In one or more embodiments, the cover plate 320 may be configured to seal the open end of the housing and may be formed of the same material as the housing (e.g., a conductive material). The cover plate 320 may be coupled to the housing by welding. The cover plate 320 may include a first through-hole 322. The vent 340 may be installed in the first through-hole 322 of the cover plate 320. The vent 340 may include a notch that allows the vent 340 to open under a predetermined pressure.

[0071] The dimensions of the insulating plate 360 ​​may correspond to the dimensions of the cover plate 320. The insulating plate 360 ​​may be located below the cover plate 320. The insulating plate 360 ​​may include a second through hole 362. The second through hole 362 of the insulating plate 360 ​​may be formed at a position corresponding to (e.g., aligned with) the first through hole 322 of the cover plate 320.

[0072] The insulating plate may include a main body portion 364 having a second through hole 362, a sidewall 365 formed to extend upward along the edge of the main body portion 364, and a curved portion connecting the main body portion and the sidewall. (Refer to...) Figure 8A , 8B as well as Figure 9 A more detailed description of the structure of the curved section.

[0073] The stepped portion 366 can be formed on the lower surface of the insulating plate 360. For example, the stepped portion 366 can be formed on the outer side of the curved portion of the insulating plate 360. The stepped portion 366 can be formed along the longitudinal direction of the second through hole 362.

[0074] The stepped portion 366 can be formed to at least partially overlap with the second through hole 362 in the short-side direction of the insulating plate 360. In the short-side direction of the insulating plate 360, the center of the stepped portion 366 and the center of the second through hole 362 may not be aligned on the same straight line. For example, the stepped portion 366 may be formed on the outer side of the curved portion of the insulating plate 360 ​​at a position away from the center of the second through hole 362 and closer to one end of the second through hole 362. In this case, the stepped portion 366 can be formed to at least partially overlap with the second through hole 362 in the short-side direction of the insulating plate 360. In other embodiments, such as... Figure 3 As illustrated, the stepped portion 366 can be formed such that the center of the second through hole 362 and the center of the stepped portion 366 are aligned on the same straight line (e.g., line B-B') in the direction of the short side of the insulating plate 360.

[0075] The center of the stepped portion 366 can be aligned in a straight line with the center of the grooves 442 and 444 (grooves 442 and 444 are formed as recesses) on the lower surface of the cover plate 320 in the direction of the short side of the insulating plate 360 ​​(see...). Figure 4A and Figure 4B By forming the stepped portion 366 and the grooves 442 and 444 in this way, further damage to the secondary battery can be prevented during the rupture of the venting component.

[0076] The insulating plate 360 ​​may include ribs 368 connecting the main body portion 364 and the side wall 365. The ribs 368 may be formed to prevent the insulating plate 360 ​​from bending and to enhance the rigidity of the insulating plate 360. Furthermore, multiple ribs 368 may be provided.

[0077] Figure 4A and Figure 4B The illustration shows an example of the lower surface of a cover plate according to one or more embodiments of the present disclosure.

[0078] Grooves 442 and 444 may be formed on the lower surface of cover plate 320. Grooves 442 and 444 may be formed on the lower surface of cover plate 320 to guide (cause) bending of cover plate 320 at grooves 442 and 444 during the rupture of the exhaust element. Upon rupture of the exhaust element, grooves 442 and 444 may cause the cover plate 320 to bend upwards. This upward bending of cover plate 320 may prevent damage to the diaphragm of the electrode assembly.

[0079] Figure 4A The illustration shows an example of each of the recesses 442 and 444 formed near the first through hole 322 according to one or more embodiments of the present disclosure. The recesses 442 and 444 may be formed as recesses on the lower surface of the cover plate 320.

[0080] Recesses 442 and 444 may include a first recess 442 and a second recess 444. Each of the first recess 442 and the second recess 444 may be formed between the first through-hole 322 and the housing weld portion 460 (e.g., formed at the edge of the first through-hole 322). The housing weld portion 460 may be formed along the long side direction (longitudinal direction) of the cover plate 320. The housing weld portion 460 may be used to connect the cover plate 320 and the housing, and may correspond to the thickness surface or side surface of the cover plate 320. Hereinafter, the housing weld portion 460 may be referred to as the "welded portion".

[0081] Each of the first groove 442 and the second groove 444 can be formed along the longitudinal direction of the first through hole 322 or the longitudinal direction of the cover plate 320. In the short-side direction of the cover plate 320, each of the first groove 442 and the second groove 444 can be formed at a position that at least partially overlaps with the first through hole 322. In the short-side direction of the cover plate 320, the centers of the first groove 442 and the second groove 444 may not be aligned with the center of the first through hole 322. For example, each of the first groove 442 and the second groove 444 can be formed at a position away from the center of the first through hole 322 and closer to one end of the first through hole 322. In this case, each of the first groove 442 and the second groove 444 can be formed in the short-side direction of the cover plate 320 at a position overlapping with the first through hole 322. In other embodiments, such as Figure 4A As shown in the figure, in the short side direction of the cover plate 320, the centers of the first groove 442 and the second groove 444 can be aligned with the center of the first through hole 322 on the same straight line.

[0082] Each of the first groove 442 and the second groove 444 can be formed to have a depth less than the thickness of the cover plate 320. Figure 4AIn the illustrated example, each of grooves 442 and 444 has a rectangular shape, but it could also be other shapes.

[0083] Figure 4B The illustration shows an example of each of the grooves 442 and 444, according to another embodiment of the present disclosure, being spaced apart from the first through hole 322. The grooves 442 and 444 may be formed as recesses on the lower surface of the cover plate 320.

[0084] Grooves 442 and 444 can be disposed between the first through hole 322 and the edge of the cover plate 320. Grooves 442 and 444 can include a first groove 442 and a second groove 444. Each of the first groove 442 and the second groove 444 can be formed between the first through hole 322 and the housing welding portion 460. The housing welding portion 460 can be formed along the longitudinal direction of the cover plate 320. The housing welding portion 460 can be used to connect the cover plate 320 and the housing, and can correspond to the thickness surface or side surface of the cover plate 320.

[0085] Each of the first groove 442 and the second groove 444 may be formed along the longitudinal direction of the first through hole 322 or the longitudinal direction of the cover plate 320. In the short-side direction of the cover plate 320, each of the first groove 442 and the second groove 444 may be formed at a position that at least partially overlaps with the first through hole 322. In one or more embodiments, in the short-side direction of the cover plate 320, the centers of the first groove 442 and the second groove 444 may not be aligned with the center of the first through hole 322 on the same straight line. For example, each of the first groove 442 and the second groove 444 may be formed at a position away from the center of the first through hole 322 and closer to one end of the first through hole 322. In this case, each of the first groove 442 and the second groove 444 may be formed in the short-side direction of the cover plate 320 at a position overlapping with the first through hole 322. In other embodiments, in the short-side direction of the cover plate 320, such as... Figure 4B As shown in the figure, the centers of the first groove 442 and the second groove 444 can be aligned with the center of the first through hole 322 on the same straight line.

[0086] Figure 5 It is a diagram. Figure 4B A bottom view of an example of the lower surface of cover plate 320.

[0087] like Figure 5 As shown, grooves 442 and 444 can be formed on the lower surface of cover plate 320.

[0088] The grooves 442 and 444 may include a first groove 442 and a second groove 444. Each of the first groove 442 and the second groove 444 may be spaced apart from the first through hole 322, which is located between the first groove 442 and the second groove 440. Each of the first groove 442 and the second groove 444 may be disposed between the first through hole 322 and the housing welded portion 460. The first groove 442 and the second groove 444 may be positioned such that the centers of the first groove 442 and the second groove 444 are aligned on the same straight line with the center of the first through hole 322 in the short side direction of the cover plate 320.

[0089] Figure 6 It is along Figure 3 A cross-sectional view taken from line A-A'.

[0090] The cover plate 320 may include recesses 442 and 444 located on the opposite side of the first through hole 322. Recesses 442 and 444 may include a first recess 442 and a second recess 444. Recesses 442 and 444 may be formed as recesses on the lower surface of the cover plate. Each of the first recess 442 and the second recess 444 may be formed with a depth less than the thickness of the cover plate 320. Each of the first recess 442 and the second recess 444 may be located between the first through hole 322 and the housing weld portion 460. The housing weld portion 460 may be a portion welded to connect the housing to the cover plate 320. Therefore, recesses 442 and 444 may be arranged not to overlap with the housing weld portion 460.

[0091] Figure 7 The illustration shows an example of a cover plate bending upwards due to a groove according to one or more embodiments of the present disclosure.

[0092] For example, if an external impact is applied to the secondary battery in the y-axis direction, the vent may break. Due to the external impact, the cover 710 may bend. The bending of the cover 710 can be guided in the upward (or x-axis) direction 750 by a groove formed on the lower surface of the cover 710. In one or more embodiments, Figure 7 The dashed line shown indicates that the cover plate 710 is in an upwardly bent position. When the cover plate 710 is bent in the upward direction 750, the cover plate 710 does not apply pressure to the insulating plate, which prevents the insulating plate 720 from compressing the electrode assembly 730. By preventing the insulating plate 720 from compressing the electrode assembly 730, the risk of damage to the diaphragm caused by the cover plate 710 can be avoided.

[0093] Figure 8A and Figure 8B The illustration shows an example of an insulating plate 360 ​​according to one or more embodiments of the present disclosure.

[0094] Figure 8A Show along Figure 3 A perspective cross-sectional view taken along line B-B'. The second through-hole 362 of the insulating plate 360 ​​can be formed at a position corresponding to the first through-hole 322 of the cover plate 320. The main body portion 364 can have an integral plate shape. The second through-hole 362 can be formed in the main body portion 364. The sidewall 365 can be formed to extend upward along the edge of the main body portion 364. The main body portion 364 and the sidewall 365 can be connected by a curved portion. A stepped portion 366 can be formed at the curved portion of the insulating plate 360.

[0095] The curved portion may include a first curved surface 832, a second curved surface 834, and a third curved surface 836. The first curved surface 832 may be formed on the inner surface of the insulating plate 360. The first curved surface 832 may be formed by structurally connecting the main body portion 364 and the sidewall 820 on the inner side of the insulating plate 360. The first curved surface 832 may have a radius of curvature of 0.5 mm or more.

[0096] The second curved surface 834 can be formed offset from the thickness of the insulating plate 360 ​​from the first curved surface 832. The second curved surface 834 can be formed on the outer surface of the insulating plate 360. For example, the second curved surface 834 can be formed on the stepped portion 366 (i.e., the second curved surface 834 can form a part of the stepped portion 366), and the second curved surface 834 can form a part of the outer surface of the insulating plate 360. The second curved surface 834 can have a radius of curvature of 2 mm or more. The third curved surface 836 can be formed on the outermost surface of the insulating plate 360. The third curved surface 836 can have a radius of curvature of 2 mm or more.

[0097] The insulating plate 360 ​​may include ribs 368. Ribs 368 may structurally connect the main body portion 364 and the sidewall 820. Ribs 368 may be formed to prevent bending and enhance the strength of the insulating plate 360. The insulating plate 360 ​​may include multiple ribs 368.

[0098] Figure 8B It is along Figure 3 The cross-sectional view is taken along line B-B'. A first curved surface 832 may be formed on the inner surface of the insulating plate 360. A second curved surface 834 may be formed offset from the thickness of the insulating plate 360 ​​from the first curved surface 832, and may be formed on the outer surface of the insulating plate 360. The second curved surface 834 may have a radius of curvature of 2 mm or more. A third curved surface 836 may be formed on the outermost surface of the insulating plate 360. The third curved surface 836 may have a radius of curvature of 2 mm or more.

[0099] Figure 9The illustration shows an example of the lower surface of an insulating plate according to one or more embodiments of the present disclosure.

[0100] The second through hole 362 of the insulating plate 360 ​​may be formed at a position corresponding to (e.g., aligned with) the first through hole 322 of the cover plate 320. A stepped portion 366 may be formed on the lower surface of the insulating plate 360. The stepped portion 366 may contact the second through hole 362.

[0101] In the short side direction of the insulating plate 360, the center of the stepped portion 366 and the center of the second through hole 362 can be aligned on the same straight line. At the edge of the lower surface of the insulating plate 360, a second curved surface 834 and a third curved surface 836 can be formed.

[0102] According to various embodiments of this disclosure, a groove is formed on the lower surface of the cover plate. Therefore, when an impact is applied to the secondary battery, the cover plate can bend upward, thereby preventing damage to the separator of the electrode assembly.

[0103] According to various embodiments of this disclosure, the bent portion is formed on the lower surface of the insulating plate. Therefore, when an impact is applied to the secondary battery, the risk of impact can be reduced, thereby reducing the load and sharpness applied to the electrode assembly.

[0104] Although this disclosure has been described with reference to the accompanying drawings illustrating embodiments and various aspects thereof, this disclosure is not limited thereto. Various modifications and variations can be made by those skilled in the art within the scope of this disclosure and the following claims and their equivalents.

[0105] Exemplary embodiments have been disclosed herein, and although specific terminology has been used, it is used and interpreted in a general and descriptive sense only and not for limiting purposes. In some instances, as will be apparent to those skilled in the art at the time of filing this application, unless otherwise specifically indicated, features, characteristics, and / or elements described in connection with particular embodiments may be used alone or in combination with features, characteristics, and / or elements described in connection with other embodiments. Accordingly, those skilled in the art will understand that various changes in form and detail may be made without departing from the spirit and scope of the invention as set forth in the following claims.

Claims

1. A cover assembly, comprising: A cover plate having a first through hole; and An insulating plate, located beneath the cover plate, has a second through hole aligned with the first through hole. The insulating plate includes a main body portion having the second through hole, a sidewall extending upward along the edge of the main body portion, and a curved portion connecting the main body portion and the sidewall.

2. The cover assembly according to claim 1, wherein: The cover plate includes a groove on its lower surface, and The groove is located between the first through hole and the edge of the cover plate.

3. The cover assembly according to claim 2, wherein: The groove includes a first groove and a second groove. The first groove and the second groove are along the longitudinal direction of the first through hole. The welded portion extends along the edge of the cover plate in the longitudinal direction, and Each of the first groove and the second groove is located in the region between the first through hole and the welded portion.

4. The cover assembly according to claim 2, wherein, In the direction of the short side of the cover plate, the groove at least partially overlaps with the first through hole.

5. The cover assembly according to claim 4, wherein, The center of the groove and the center of the first through hole are aligned on the same straight line along the short side of the cover plate.

6. The cover assembly according to any one of claims 1 to 5, further comprising a stepped portion on the outer side of the curved portion of the insulating plate.

7. The cover assembly according to claim 6, wherein, In the direction of the short side of the insulating plate, the stepped portion at least partially overlaps with the second through hole.

8. The cover assembly according to claim 7, wherein, The center of the stepped portion and the center of the second through hole are aligned on the same straight line in the direction of the short side of the insulating plate.

9. The cover assembly according to claim 6, wherein, The curved portion includes: The first curved surface on the inner surface of the insulating plate, and A second curved surface offset from the thickness of the insulating plate from the first curved surface, the second curved surface being on the stepped portion.

10. The cover assembly according to claim 9, wherein, The curved portion further includes a third curved surface on the outermost surface of the insulating plate.

11. The cover assembly according to claim 10, wherein, The radius of curvature of the first curved surface is equal to or greater than 0.5 mm.

12. The cover assembly according to claim 11, wherein, The radius of curvature of each of the second and third curved surfaces is equal to or greater than 2 mm.

13. The cover assembly according to any one of claims 1 to 5, wherein, The insulating plate further includes ribs connecting the main body portion and the sidewall.

14. A secondary battery, comprising: The electrode assembly includes a first electrode plate, a second electrode plate, and a diaphragm; A housing that accommodates the electrode assembly, the housing having an open end; A cover plate, connected to the open end of the housing, the cover plate including a first through hole; and An insulating plate, located beneath the cover plate, includes a second through hole aligned with the first through hole. The insulating plate includes a main body portion having the second through hole, a sidewall extending upward along the edge of the main body portion, and a curved portion connecting the main body portion and the sidewall. The curved portion has a radius of curvature.

15. The secondary battery according to claim 14, wherein: The cover plate further includes a groove on the lower surface of the cover plate, and The groove is located between the first through hole and the edge of the cover plate.

16. The secondary battery according to claim 15, wherein: The groove includes a first groove and a second groove. The first groove and the second groove are along the longitudinal direction of the first through hole. The welded portion extends along the edge of the cover plate in the longitudinal direction, and Each of the first groove and the second groove is located in the region between the first through hole and the welded portion.

17. The secondary battery according to any one of claims 14 to 16, wherein: The stepped portion is located on the outside of the curved portion of the insulating plate, and The stepped portion at least partially overlaps with the second through hole in the direction of the short side of the insulating plate.

18. The secondary battery according to claim 17, wherein, The curved portion includes: The first curved surface on the inner surface of the insulating plate, and A second curved surface offset from the thickness of the insulating plate from the first curved surface, the second curved surface being on the stepped portion, and The third curved surface on the outermost surface of the insulating plate.

19. The secondary battery according to claim 18, wherein, The radius of curvature of the first curved surface is equal to or greater than 0.5 mm.

20. The secondary battery according to claim 18, wherein, The radius of curvature of each of the second and third curved surfaces is equal to or greater than 2 mm.

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