Cover plate, battery cell, battery pack including battery cell, and vehicle

Abstract

Disclosed are a cover plate, a battery cell, a battery pack including the battery cell, and a vehicle. The cover plate according to one embodiment of the present invention is a cover plate coupled to a battery can, the cover plate including: a main body portion for sealing the battery can; a vent cut portion formed in the main body portion and ruptured when a pressure inside the battery can exceeds a threshold value; and a rupture induction portion spaced apart from the vent cut portion and formed in the main body portion such that the vent cut portion can be ruptured at a predetermined position.

Description

Technical Field

[0001] This application is based on and claims priority to Korean Patent Application No. 10-2024-0184960, filed with the Korean Intellectual Property Office on December 12, 2024, the disclosure of which is incorporated herein by reference in its entirety.

[0002] This disclosure relates to a cover, a battery cell, and a battery pack and vehicle including the battery cell, and more specifically, to a cover, a battery cell, and a battery pack and vehicle including the battery cell that are prone to cracking during a thermal event. Background Technology

[0003] Secondary batteries, which are easy to apply to various product types and have high energy density as an electrical characteristic, are widely used not only in portable devices, but also in electric vehicles (EVs) and hybrid electric vehicles (HEVs) powered by power sources.

[0004] Secondary batteries offer the significant advantage of reducing fossil fuel consumption, and they do not produce byproducts during energy use. Therefore, secondary batteries are attracting attention as a new energy source for enhancing environmental sustainability and energy efficiency.

[0005] Currently, widely used rechargeable battery types include lithium-ion batteries, lithium polymer batteries, nickel-cadmium batteries, nickel-metal hydride batteries, and nickel-zinc batteries. These rechargeable cells have an operating voltage of approximately 2.5V to 4.5V.

[0006] Therefore, when a higher output voltage is required, multiple battery cells are connected in series to form a battery module or battery pack. Furthermore, depending on the required charging and discharging capacity, multiple battery cells can be connected in parallel to form a battery module or battery pack. Thus, the number of battery cells included in a battery module or battery pack and their electrical connection type can be variously configured based on at least one of the required output voltage and the required charging and discharging capacity.

[0007] Meanwhile, cylindrical, prismatic, and pouch-type battery cells are known as types of secondary battery cells. In the case of cylindrical battery cells, a separator, which serves as an insulator, is inserted between the positive and negative electrode plates and wound together to form a wound-core electrode assembly. Then, the electrode assembly and electrolyte are inserted together into a battery can to manufacture a battery.

[0008] Figure 1 This is a perspective view of a standard cover plate. The cover plate is attached to the battery canister containing the cylindrical battery cells.

[0009] refer to Figure 1 An exhaust vent 2 is formed in the cover plate 1, and it is configured to rupture when the pressure inside the battery tank exceeds a threshold. Figure 1The illustration of the battery can is omitted, and only the cover plate 1 is shown.

[0010] Because the exhaust vent 2 of the cover plate 1 is very thin, it may easily crack in the event of a thermal event. However, there are limitations to making the exhaust vent 2 thinner through processing.

[0011] In addition, when the thickness of the exhaust cut 2 is reduced to a certain level or smaller, the following problems may occur: leakage of electrolyte, gas, etc. may occur due to cracks generated during the activation process of the battery cell. Summary of the Invention

[0012] Technical issues

[0013] This disclosure provides a cover plate, a battery cell, a battery pack including the battery cell, and a vehicle, the cover plate having a structure in which the exhaust cut-out portion can be easily broken by a fracture induction portion, even if the exhaust cut-out portion is formed to have a thickness greater than a certain level.

[0014] In addition, this disclosure provides a cover plate, a battery cell, a battery pack including the battery cell, and a vehicle, the cover plate having a structure capable of specifying the location in the exhaust cutout where rupture and exhaust may occur.

[0015] Furthermore, this disclosure provides a cover plate, battery cell, battery pack including battery cell, and vehicle that can improve mass production and facilitate management.

[0016] The purposes intended to be achieved by this disclosure are not limited to those described above, and other purposes not described herein may be clearly understood by those skilled in the art from the following description of the invention.

[0017] Technical solution

[0018] One aspect of this disclosure provides a cover plate connected to a battery can. The cover plate includes: a body portion that seals the battery can; a venting cutout portion formed in the body portion and rupturing when the pressure inside the battery can exceeds a threshold; and a rupture induction portion formed in the body portion while being spaced apart from the venting cutout portion and inducing the venting cutout portion to rupture at a predetermined location.

[0019] In one embodiment, at least one rigid reinforcement portion may be formed in the main body portion, and the fracture inducing portion may be formed between multiple rigid reinforcement portions.

[0020] In one embodiment, the rigidity reinforcement may be configured to form a recessed groove in the main body portion at the inner side of the exhaust cut-out portion.

[0021] In one embodiment, three grooves may be formed, and a fracture induction section may be formed between two of the three grooves.

[0022] In one embodiment, three fracture induction portions may be formed, and a central portion may be formed at the intersection of the three fracture induction portions to be linearly connected to each of the three fracture induction portions.

[0023] In one embodiment, the three fracture induction sections can be spaced apart from each other at an angle of 120°.

[0024] In one embodiment, the rigidity reinforcement may include: a first portion formed inside the exhaust cut-out portion; a second portion extending from one side of the first portion toward the inside of the main body portion; a third portion extending from the opposite side of the first portion toward the inside of the main body portion; and a fourth portion connecting the second portion and the third portion.

[0025] In one embodiment, the exhaust cut may include a curve, and the first portion may include a curve parallel to a portion of the curve of the exhaust cut.

[0026] In an implementation, the second part and the third part may be formed in a linear shape.

[0027] In an implementation, the virtual extension lines of the second part and the virtual extension lines of the third part can be formed to intersect each other.

[0028] In an implementation, the fourth portion may include a curve parallel to a portion of the curve of the first portion.

[0029] According to another aspect of this disclosure, a battery cell includes: an electrode assembly including a positive electrode plate, a negative electrode plate, and a separator inserted between the positive electrode plate and the negative electrode plate; a battery can containing the electrode assembly therein and including an opening and a closing portion; and a cover plate sealing the opening of the battery can.

[0030] In one embodiment, the battery cell may further include: a sealing gasket inserted between the edge of the cover and the opening of the battery can, and the battery can may include: a rolled edge formed by pressing the outer peripheral surface of the battery can inward; and a crimping portion extending and bending toward the inside of the battery can, such that the crimping portion and the sealing gasket together wrap around and secure the edge of the cover.

[0031] Another aspect of this disclosure may provide a battery pack including at least one of the above-described battery cells, and a vehicle including at least one of the above-described battery packs.

[0032] Beneficial effects

[0033] According to embodiments of this disclosure, even if the exhaust cut portion is formed to have a thickness greater than a certain level, the exhaust cut portion can be easily broken by the breakage induction portion.

[0034] In addition, the location in the exhaust cut that may crack and release gas can be specified.

[0035] In addition, it can improve mass production capabilities and facilitate management.

[0036] The effects that can be achieved through this disclosure are not limited to those described above, and those skilled in the art will clearly understand from the following description of the invention other technical effects not described herein. Attached Figure Description

[0037] The accompanying drawings are for illustrative purposes only and, together with the description herein, are intended to further facilitate understanding of the technical concepts of this disclosure. Therefore, this disclosure should not be construed as limited to the contents shown in the drawings.

[0038] Figure 1 This is a perspective view of a standard cover plate.

[0039] Figure 2 This is a perspective view of the cover plate according to an embodiment of the present disclosure.

[0040] Figure 3 It shows along Figure 2 A perspective view of the cross section cut by line A-A' in the diagram.

[0041] Figure 4 It is along Figure 2 The cross-sectional view when observing line A-A' in the middle.

[0042] Figure 5 It shows along Figure 2 A perspective view of the cross section cut by line B-B' in the diagram.

[0043] Figure 6 It is along Figure 2 The cross-sectional view when observing line B-B' in the middle.

[0044] Figure 7 This is a cross-sectional view showing the state in which the cover plate according to an embodiment of the present disclosure is connected to the battery cell according to an embodiment of the present disclosure.

[0045] Figure 8 This is a view showing the battery canister in a battery cell according to an embodiment of the present disclosure.

[0046] Figure 9 This is a graph showing the correlation between the exhaust pressure in the cover plate according to an embodiment of the present disclosure and the thickness of the exhaust cut portion.

[0047] Figure 10 This is a graph showing the correlation between the venting pressure and the thickness of the venting cut in a battery cell including a cover plate according to an embodiment of the present disclosure.

[0048] Figure 11 It is a graph showing the change in the center of the cover plate when exhaust pressure is applied to the cover plate according to an embodiment of the present disclosure.

[0049] Figure 12 It is a graph showing the change in the outer diameter of the cover plate when exhaust pressure is applied to the cover plate according to an embodiment of the present disclosure.

[0050] Figure 13 This is a schematic view illustrating the configuration of a battery pack including battery cells according to various embodiments of the present disclosure.

[0051] Figure 14 It shows including Figure 13 A view of the vehicle with its battery pack. Detailed Implementation

[0052] Preferred embodiments of this disclosure will be described in detail below with reference to the accompanying drawings. The words and terms used in the detailed description and claims should not be construed as limited to their ordinary or dictionary meanings, but rather as having meanings and concepts corresponding to the technical concept of this disclosure, in accordance with the principle that the inventor can appropriately define terms and concepts to best describe this disclosure. Therefore, it is understood that the embodiments described herein and the configurations shown in the drawings are merely the most preferred embodiments of this disclosure and do not fully represent the technical concept of this disclosure; various equivalents and modifications can be made to replace this disclosure upon filing this application.

[0053] In the accompanying drawings, for ease of description and clarity, each component or specific part thereof is exaggerated, omitted, or shown schematically. Therefore, the dimensions of each component may not accurately reflect its actual dimensions. Detailed descriptions of related known functions or configurations may be omitted if determining that such determinations might obscure the main points of this disclosure.

[0054] As used herein, the terms “connection” and “link” refer not only to a situation where one component is directly connected to or linked to another component, but also to a situation where one component is indirectly connected to or linked to another component via a connecting component.

[0055] Figure 2 This is a perspective view of the cover plate according to an embodiment of the present disclosure. Figure 3 It shows along Figure 2 A perspective view of the cross-section taken by line A-A' in the diagram. Figure 4 It is along Figure 2 A cross-sectional view when observing line A-A' in the middle. Figure 5 It shows along Figure 2 A perspective view of the cross-section taken by line B-B' in the diagram, and Figure 6 It is along Figure 2 The cross-sectional view when observing line B-B' in the middle.

[0056] refer to Figure 2 According to the present disclosure, the cover plate 10 is connected to the battery tank 210 and includes a main body 100, an exhaust vent 110 and a rupture induction part 120.

[0057] The main body 100 is connected to the battery canister 210 of the battery cell 20 and the battery canister 210 is sealed. (Reference) Figure 7 and Figure 8 When the battery canister 210 of the battery cell 20 includes an opening 211 and a closing portion 212, the main body 100 is configured to seal the opening 211 of the battery canister 210.

[0058] The sealing gasket 220 can be attached to the edge of the main body 100 to ensure the airtightness of the battery canister 210.

[0059] An exhaust vent 110 is formed in the main body 100 to rupture in the event of a thermal event, thereby releasing gas from inside the battery canister 210. Here, the exhaust vent 110 is formed as a region with a thickness thinner than the peripheral region of the main body 100, and is configured to rupture when the pressure inside the battery canister 210 exceeds a threshold.

[0060] Because the vent cutout 110 is thinner than the surrounding area, the vent cutout 110 can rupture more easily, and when the pressure inside the battery canister 210 increases to a certain level or higher, the vent cutout 110 ruptures, and the gas generated inside the battery canister 210 can be released. For example, the vent cutout 110 can be formed by slotting.

[0061] The exhaust cutout 110 can have various shapes. For example, the exhaust cutout can be formed in the surface of the cover plate 10 as at least one of a continuous circular pattern, a discontinuous circular pattern, and a linear pattern. In addition, the exhaust cutout can be formed in various other patterns.

[0062] Here, the exhaust cutout 110 can be formed in various shapes, including curves, for example, it can be formed as follows: Figure 2The shape of the exhaust cutout 110 is circular, but it is not limited to this. For ease of description, the exhaust cutout 110 will be described assuming it is circular in the following text.

[0063] The fracture induction portion 120 is formed to be spaced apart from the exhaust cut portion 110. The fracture induction portion 120 can be formed in various locations, for example, it can be formed inside the exhaust cut portion 110, but is not limited thereto. For ease of description, the following description will assume that the fracture induction portion 120 is formed inside the exhaust cut portion 110.

[0064] Here, the inner and outer sides are defined based on the radial direction of the cover plate 10. That is, in the radial direction, the side whose diameter increases from the center of the cover plate 10 will be called the outer side, while the side whose diameter decreases from the center of the cover plate 10 will be called the inner side.

[0065] A fracture induction portion 120 is formed in the main body portion 100, so that the exhaust cut portion 110 can easily fracture at a predetermined position.

[0066] When the exhaust cut is formed into a circular shape with uniform thickness, such as Figure 1 Conventional venting covers have the following problem: when a thermal event causes an increase in internal pressure in the battery tank, it is difficult to predict which part of the venting opening will rupture. That is, since any part of the venting opening can rupture, it is difficult to accurately predict which part will rupture, which may reduce gas emission efficiency.

[0067] To address the aforementioned conventional problems, a rupture induction portion 120 is formed in the cover plate 10 according to an embodiment of this disclosure. That is, when the pressure inside the battery canister 210 increases, the vent cut portion 110 can easily rupture at the location where the rupture induction portion 120 is formed. Therefore, the cover plate 10 can be designed such that the vent cut portion 110 ruptures at a predetermined location.

[0068] Furthermore, references will be described later. Figure 9 and Figure 10 To prevent the cover plate 10 from cracking, an exhaust cutout 110 with a greater thickness for the same exhaust pressure can be formed in the cover plate 10.

[0069] refer to Figures 2 to 4 At least one rigid reinforcement portion 101 may be formed in the main body portion 100. The rigid reinforcement portion 101 may be formed in various shapes, and for example, it may be configured as a groove 102 formed in a recessed shape in the main body portion 100 at the inner side of the exhaust cutout portion 110.

[0070] When a groove 102 is formed in the main body 100, the bending stiffness (bending rigidity) in the region of the groove 102 increases.

[0071] When the groove 102 is formed in the main body 100, the second moment of section changes due to the change in cross-sectional shape. That is, when the groove 102 is formed, the material is redistributed to a region farther from the neutral axis, resulting in an increase in the second moment of section. Since bending stiffness is proportional to the second moment of section, both the second moment of section and bending stiffness increase when the groove 102 is formed in the main body 100.

[0072] The portion of the main body 100 in which the groove 102 is formed has enhanced bending stiffness compared to the portion in which the groove 102 is not formed, and therefore can be used as a rigidity reinforcement portion 101.

[0073] refer to Figure 2 , Figure 3 and Figure 5 The groove 102 may include a first part 103, a second part 104, a third part 105, and a fourth part 106.

[0074] The first portion 103 is formed inside the exhaust cut-out portion 110. The first portion 103 can be formed in various shapes. For example, as described above, when the exhaust cut-out portion 110 is formed in a circular shape among various shapes including curves, the first portion 103 may include a curve parallel to a portion of the curve of the exhaust cut-out portion 110. However, the shape of the first portion 103 is not limited to this.

[0075] The description that a portion of the curve of the exhaust cutout 110 is parallel to the curve of the first portion 103 indicates that both the portion of the exhaust cutout 110 and the first portion 103 are curved but do not intersect each other. This configuration is merely an example, and the portion of the curve of the exhaust cutout 110 and the curve of the first portion 103 do not necessarily have to be parallel to each other.

[0076] The second part 104 extends from one side of the first part 103 toward the inside of the main body 100. Here, the second part 104 can be formed in a linear shape.

[0077] The third part 105 extends from the opposite side of the first part 103 toward the inside of the main body 100. The third part 105 may be formed in a linear shape.

[0078] The second part 104 and the third part 105 can be configured such that their virtual extensions intersect each other. That is, this configuration means that the second part 104 and the third part 105 are not parallel to each other.

[0079] The fourth part 106 is configured to connect the second part 104 and the third part 105. The fourth part 106 may have various shapes and, for example, may include a curve parallel to a portion of the curve of the first part 103, but is not limited thereto.

[0080] refer to Figure 2 The fracture inducing portion 120 may be formed between multiple rigid reinforcement portions 101 (e.g., between multiple grooves 102). The fracture inducing portion 120 itself does not fracture, but induces fracture in the exhaust cut portion 110 located near the portion where the fracture inducing portion 120 is formed.

[0081] As described above, when the groove 102 is formed in the main body 100, the bending stiffness in the groove 102 increases compared to the fracture induction portion 120 where the groove 102 is not formed. Therefore, the vent cutout portion 110 located near the portion where the groove 102 is formed is less likely to fracture.

[0082] That is, even if the entire exhaust cut 110 has a uniform thickness and the same pressure is applied to the exhaust cut 110, cracking hardly occurs in the exhaust cut 110 that is positioned adjacent to the groove 102 which has enhanced bending stiffness and is therefore not easily deformed, while cracking is relatively easy to occur in the exhaust cut 110 that is positioned adjacent to the crack induction portion 120 formed between the grooves 102.

[0083] As a result, even if the exhaust cut portion 110 is formed to have a thickness greater than a certain level, the exhaust cut portion 110 can be easily broken by the fracture induction portion 120.

[0084] The rupture induction section 120 induces rupture in the exhaust cut section 110 located adjacent to it, thereby allowing the location in the exhaust cut section 110 where exhaust may occur to be specified.

[0085] When the exhaust position in the exhaust port is specified, gases can be discharged in a specific direction, which is advantageous when designing battery cell 20, improving mass production capability and facilitating management.

[0086] refer to Figure 2 It is possible to form three grooves 102. However, the number of grooves 102 can vary, and the case of forming three grooves 102 is merely an example. For ease of description, the following description will assume the case of forming three grooves 102.

[0087] In addition, a fracture induction section 120 may be formed between two of the three grooves 102.

[0088] refer to Figure 2 It is possible to form three fracture induction sections 120. However, the number of the three fracture induction sections 120 can vary, and forming three fracture induction sections 120 is merely one embodiment. However, for ease of explanation, the following description will focus on the case where three fracture induction sections 120 are present.

[0089] refer to Figure 2 According to an embodiment, a central portion 130 may be formed at the intersection of the three fracture-inducing portions 120. (See reference...) Figure 5 and Figure 6 Each fracture inducing portion 120 and the center portion 130 can be connected by a straight line. That is, the fracture inducing portion 120 and the center portion 130 are located on the same straight line, and the groove 102 is formed to be recessed below the fracture inducing portion 120 and the center portion 130. Here, the groove 102 can be formed, for example, by stamping.

[0090] In addition, return to reference Figure 2 The three fracture induction sections 120 may be spaced apart from each other by about 120°. However, this disclosure is not limited thereto.

[0091] Figure 7 This is a cross-sectional view showing the state in which the cover plate according to an embodiment of the present disclosure is connected to the battery cell according to an embodiment of the present disclosure, and Figure 8 This is a view showing the battery can of a battery cell according to an embodiment of the present disclosure.

[0092] refer to Figure 7 According to the embodiments of the present disclosure, the battery cell 20 includes an electrode assembly 200, a battery canister 210, and a cover plate 10.

[0093] The electrode assembly 200 includes a positive electrode plate, a negative electrode plate, and a separator inserted between the positive and negative electrode plates, and may have a structure in which the positive electrode plate, negative electrode plate, and separator are wound in one direction. A central hole 201 is formed at the center of the electrode assembly 200, and the electrode assembly 200 may be formed in a wound core shape.

[0094] For example, the electrode assembly 200 can be manufactured by winding a stacked structure in which the negative electrode plate, the separator, the positive electrode plate, and the separator are stacked at least once in this order. Here, the positive electrode plate and the negative electrode plate can be formed in sheet form.

[0095] That is, the electrode assembly 200 used in this embodiment can be a wound electrode assembly 200. In this case, an additional diaphragm can be provided on the outer peripheral surface of the electrode assembly 200 to ensure insulation from the battery canister 210. That is, the electrode assembly 200 can have any wound structure known in the art without limitation.

[0096] The positive electrode active material is coated on one or both surfaces of the positive electrode plate, and a first uncoated portion without the positive electrode active material can be formed at the end of the positive electrode plate. By forming multiple winding turns around the center of the electrode assembly 200, the first uncoated portion can be exposed outside the separator and can therefore be used as an electrode tab. However, the positive electrode plate may not include the first uncoated portion.

[0097] The negative electrode active material is coated on one or both surfaces of the negative electrode plate, and a second uncoated portion without the negative electrode active material can be formed at the end of the negative electrode plate. By forming multiple windings around the center of the electrode assembly 200, the second uncoated portion can be exposed outside the separator and thus can be used as an electrode tab. However, the negative electrode plate may not include the second uncoated portion.

[0098] Here, when the positive electrode plate and the negative electrode plate each include an uncoated portion, the first uncoated portion and the second uncoated portion can be configured to face opposite directions.

[0099] There are no particular limitations on the positive electrode active material coated on the positive electrode plate and the negative electrode active material coated on the negative electrode plate, and they can be any active material known in the art.

[0100] The membrane can be manufactured using a porous polymer membrane formed from a polyolefin polymer, such as ethylene homopolymer, propylene homopolymer, ethylene / butene copolymer, ethylene / hexene copolymer, or ethylene / methacrylate copolymer, which can be used alone or in laminated form.

[0101] As another example, the diaphragm can be made using conventional porous nonwoven fabrics, such as nonwoven fabrics formed from glass fibers or polyethylene terephthalate fibers, for example, those with high melting points.

[0102] At least one surface of the diaphragm may include a coating of inorganic particles. The diaphragm itself may be formed from the coating of inorganic particles. The particles of the coating may be bonded together with an adhesive to form interstitial volumes between adjacent particles.

[0103] Furthermore, the center hole 201 of the electrode assembly 200 can also be used to weld the cell terminal 240 (positive electrode terminal) and the positive current collector plate 230. That is, a laser can be irradiated through the center hole 201 of the electrode assembly 200 to weld the cell terminal 240 and the positive current collector plate 230.

[0104] The electrode assembly 200 is housed within the battery canister 210. For example, the battery canister 210 may be cylindrical, and the electrode assembly 200 may be housed within the battery canister 210 such that the battery canister 210 is electrically connected to the negative electrode plate of the electrode assembly 200. Therefore, the battery canister 210 may have the same polarity as the negative electrode plate, i.e., negative polarity.

[0105] refer to Figure 8 The battery canister 210 may include a closed portion 212 and an opening portion 211 positioned relative to each other.

[0106] For example, such as Figure 8As shown, the opening 211 can be formed on the top of the battery can 210. The electrode assembly 200 can be accommodated in the battery can 210 through the opening 211 formed on the top of the battery can 210, and the electrolyte can also be injected through the opening 211 formed on the top of the battery can 210. However, the opening 211 can also be formed on the bottom of the battery can 210.

[0107] That is, the battery can 210 can be a generally cylindrical container with an opening 211 formed at the top, and is made of a conductive material such as metal. The material of the battery can 210 can be a conductive metal, such as aluminum, steel or stainless steel, but is not limited thereto. A Ni plating layer can be formed on the surface of the battery can 210.

[0108] In addition, such as Figure 8 As shown, a closure 212 can be formed at the bottom of the battery canister 210. A through-hole 215 is formed in the closure 212, and as shown... Figure 7 As shown, the cell terminal 240 can be connected to the through hole 215.

[0109] The diameter of the battery canister 210 is larger than the diameter of the electrode assembly 200. A gap of a predetermined size is formed between the battery canister 210 and the positive current collector 230, and an insulator 250 can be disposed in this gap.

[0110] When the size of the electrode assembly 200 is increased while the size of the battery can 210 is fixed according to the specifications, the total capacity of the battery cell 20 increases, but the gap between the battery can 210 and the electrode assembly 200 decreases.

[0111] That is, when the size of the electrode assembly 200 is increased to improve the total capacity of the battery cell 20, the gap between the battery can 210 and the electrode assembly 200 is reduced. Therefore, in order to improve the total capacity of the battery cell 20, the thickness of the insulator 250 can be as thin as possible, so that the insulator 250 can be disposed in the reduced gap between the battery can 210 and the electrode assembly 200.

[0112] The battery canister 210 may be a generally cylindrical container and may be formed of a conductive material such as metal. The material of the battery canister 210 may be a conductive metal, such as aluminum, steel or stainless steel, but is not limited thereto.

[0113] The cover plate 10 includes a fracture induction section 120 according to the above embodiments, and has the same configuration as described above.

[0114] The cover 10 is attached to the battery canister 210 and is configured to seal the opening 211 formed in the battery canister 210. The cover 10 may be made of, for example, a metallic material to ensure rigidity.

[0115] Furthermore, the cover plate 10 can be configured to be non-polar by being separated from the electrode assembly 200. That is, even if the cover plate 10 is formed of a conductive metal material, the cover plate 10 can be non-polar.

[0116] The description of cover 10 as having no polarity indicates that cover 10 is electrically insulated from battery canister 210 and cell terminals 240. Thus, cover 10 can be non-polarized, and its material does not necessarily have to be a conductive metal.

[0117] The cover plate 10 can be mounted and supported on the rolled edge 213 formed in the battery can 210. Furthermore, the cover plate 10 can be secured by a crimping portion 214. A sealing gasket 220 can be inserted between the cover plate 10 and the crimping portion 214 of the battery can 210 to ensure the airtightness of the battery can 210. For example, the sealing gasket 220 can be disposed between the edge of the cover plate 10 and the opening 211 of the battery can 210.

[0118] Furthermore, an exhaust vent 110 may be formed in the cover plate 10 to rupture due to the pressure inside the battery canister 210, as described above.

[0119] In the battery canister 210, a rolled edge portion 213 and a crimped portion 214 may be formed.

[0120] The rolled edge 213 is formed by pressing the outer peripheral surface of the battery can 210 inward. The rolled edge 213 supports the electrode assembly 200, which has a size substantially corresponding to the width of the battery can 210, to prevent the electrode assembly 200 from exiting the battery can 210, and can also serve as a support for the cover 10 on which it is mounted. In addition, the rolled edge 213 can support the outer peripheral surface of the sealing gasket 220.

[0121] The crimping portion 214 extends and bends toward the inside of the battery canister 210, such that the crimping portion 214 and the sealing gasket 220 together wrap around and secure the edge of the cover plate 10. Figure 7 As shown, the crimping part 214 can be Figure 7 In the view, it is formed above the crimped portion 213. This configuration is merely an example, and the positions of the crimped portion 214 and the crimped portion 213 are not limited to this.

[0122] In the crimping part 214 Figure 7 In the view, when formed above the rolled edge portion 213, the crimping portion 214 has a shape that extends and bends to wrap around the periphery of the cover plate 10 provided on the upper side of the rolled edge portion 213. By means of the bending shape of the crimping portion 214, the cover plate 10 can be fixed to the rolled edge portion 213.

[0123] The positive current collector 230 is electrically connected to the positive electrode plate of the electrode assembly 200. For example, the positive current collector 230 may be made of a conductive metal material and is electrically connected to a first uncoated portion of the positive electrode plate.

[0124] The cell terminal 240 is made of a conductive metal material and is electrically connected to the positive current collector plate 230. The cell terminal 240 is electrically connected to the positive electrode plate of the electrode assembly 200 via the positive current collector plate 230, and therefore has positive polarity.

[0125] That is, the cell terminal 240 can be used as a positive electrode terminal. At the same time, the battery canister 210 is electrically connected to the negative electrode plate of the electrode assembly 200 as described above, and therefore can have negative polarity.

[0126] The negative current collector 260 is electrically connected to the negative electrode plate of the electrode assembly 200. For example, the negative current collector 260 may be made of a conductive metal material, such as aluminum, steel, copper or nickel, and may be electrically connected to a second uncoated portion of the negative electrode plate.

[0127] At least a portion of the edge of the negative current collector plate 260 can be inserted between the inner surface of the battery canister 210 and the sealing gasket 220 and fixed therein.

[0128] Figure 9 This is a graph showing the correlation between the exhaust pressure in the cover plate according to an embodiment of the present disclosure and the thickness of the exhaust cut portion, and Figure 10 This is a graph showing the correlation between the venting pressure and the thickness of the venting cut in a battery cell including a cover plate according to an embodiment of the present disclosure.

[0129] Figure 9 This is a graph obtained by measuring the exhaust pressure of the cover plate 10, where the exhaust cutout 110 is formed. Here, a comparative example is shown. Figure 1 The conventional cover plate 10 shown is illustrated, and embodiments of this disclosure represent embodiments according to this disclosure. Figure 2 Cover plate 10.

[0130] also, Figure 10 This graph was obtained by measuring the venting pressure of the battery cell 20 connected to the battery canister 210 via a cover plate 10 having a venting cutout 110. Here, a comparative example is shown where the battery cell 20 is connected to the battery canister 210. Figure 1 The conventional cover plate 10 houses the battery cell 20, and embodiments of this disclosure indicate connection to the battery cell 20 according to embodiments of this disclosure. Figure 2 The cover plate 10 and the battery cell 20.

[0131] Right now, Figure 9 It shows according to Figure 1 The thickness of the cover plate 10 and Figure 2 A graph showing the change in exhaust pressure in relation to the thickness of the exhaust cutout 110 in the cover plate 10, and... Figure 10 It shows the connection to Figure 1The thickness of the battery cell 20 in the cover plate 10, and the connection to Figure 2 A graph showing the change in vent pressure of the thickness of the vent cutout 110 of each cover plate 10 in the battery cell 20 of the cover plate 10.

[0132] Also refer to Figure 9 and Figure 10 It can be seen that when the same exhaust pressure is applied, the thickness of the exhaust cut portion 110 in the present disclosure embodiment is greater than the thickness of the exhaust cut portion 110 in the comparative example.

[0133] For example, in Figure 9 In the comparative example, when the exhaust pressure is 30 kgf / cm², the thickness of the exhaust cut-out portion 110 is approximately 87.5 μm, while the thickness of the exhaust cut-out portion 110 in the present disclosure embodiment is approximately 102 μm. Furthermore, in Figure 10 In the comparative example, when the exhaust pressure is 30 kgf / cm², the thickness of the exhaust cut portion 110 is about 84 μm, while the thickness of the exhaust cut portion 110 in the present invention is about 102 μm.

[0134] As described in the background section, when the thickness of the vent cut 110 is reduced to a certain level or smaller, the following problem may occur: due to cracks generated during the activation process of the battery cell, leakage of electrolyte, gas, etc. may occur.

[0135] However, reference Figure 9 and Figure 10 In embodiments of this disclosure, an exhaust cutout 110 with a greater thickness under the same exhaust pressure can be formed in the cover plate 10, thereby preventing the cover plate 10 from cracking.

[0136] Furthermore, since the embodiments of this disclosure are not very sensitive to the thickness of the exhaust cut portion 110, it is easy to ensure the thickness variation tolerance of the exhaust cut portion 110, and even if the thickness of the exhaust cut portion 110 is uneven due to, for example, processing errors, it is easy to break at a predetermined position of the exhaust cut portion 110.

[0137] Figure 11 A graph showing the change in the center of the cover plate according to an embodiment of the present disclosure when exhaust pressure is applied to the cover plate.

[0138] Here, the comparative example is shown. Figure 1 The conventional cover plate 10, and the embodiments of the present disclosure represent the cover plate 10 according to the embodiments of the present disclosure.

[0139] refer to Figure 11When exhaust pressure is applied to cover plate 10, the change in the center portion 130 of cover plate 10 according to the present disclosure embodiment is less than the change in the center portion of cover plate 1 of comparative example.

[0140] That is, since the change in the center 130 of the cover plate 10 is relatively small, the deformation of the battery cell 20 in the height direction can be suppressed even if the pressure inside the battery tank 210 exceeds the threshold during a thermal event.

[0141] Figure 12 It is a graph showing the change in the outer diameter of the cover plate when exhaust pressure is applied to the cover plate according to an embodiment of the present disclosure.

[0142] exist Figure 12 In the graph, the change in the outer diameter of the cover plate 10 is represented by the value obtained by subtracting the initial outer diameter from the changed outer diameter. Since the outer diameter of the cover plate 10 decreases when exhaust pressure is applied, the change is represented as a negative (minus) value.

[0143] refer to Figure 12 The change in the outer diameter of the cover plate 10 according to the present disclosure is less than the change in the outer diameter of the comparative example.

[0144] As described above, when the cover plate 10 is fixed by the crimping part 214, if the outer diameter of the cover plate 10 shrinks, a gap may be formed between the cover plate 10 and the crimping part 214. As a result, gas may be discharged through the crimping part 214, which may reduce the safety of the battery cell 20.

[0145] However, reference Figure 12 Since the outer diameter change of the cover plate 10 according to the present disclosure embodiment is less than the outer diameter change of the cover plate 10 in the comparative example, the gas discharged through the gap between the cover plate 10 and the crimping portion 214 when a thermal event occurs in the battery cell 20 can be minimized.

[0146] Figure 13 This is a schematic view illustrating the configuration of a battery pack including battery cells according to various embodiments of the present disclosure.

[0147] refer to Figure 13 The battery pack 30 according to embodiments of the present disclosure may include one or more battery cells 20 according to the various embodiments of the present disclosure described above. Here, the battery cell 20 according to the various embodiments of the present disclosure includes a cover plate 10 according to the various embodiments of the present disclosure.

[0148] In addition, the battery pack 30 may also include a battery pack housing 31 for housing the battery cells 20, and various devices (e.g., BMS (Battery Management System), current sensors and fuses) for controlling the charging and discharging of the battery cells 20.

[0149] Figure 14 It shows including Figure 13 A view of the vehicle with its battery pack.

[0150] refer to Figure 14 The vehicle 40 according to embodiments of this disclosure may include one or more battery cells 20 or battery packs 30 according to the various embodiments of this disclosure described above. Here, vehicle 40 includes, for example, various types of vehicles that use electricity, such as electric vehicles and hybrid vehicles.

[0151] In the description herein, terms indicating direction, such as “up,” “down,” “left,” and “right,” are used for convenience of description only, and those skilled in the art will understand that these terms may vary depending on, for example, the position of an object or an observer.

[0152] While this disclosure has been described with reference to limited embodiments and accompanying drawings, it is not limited thereto, and various modifications and alterations can be made by those skilled in the art within the scope of the technical concept of this disclosure and the equivalents of the appended claims. Therefore, the above embodiments should be considered from a descriptive rather than restrictive perspective. That is, the basic scope of the technical concept of this disclosure can be found in the appended claims, and any differences falling within the scope of equivalents of this disclosure should be interpreted as including within this disclosure.

[0153] Industrial applicability

[0154] This disclosure relates to a cover plate, a battery cell, and a battery pack and vehicle including the battery cell, and is particularly applicable to industries related to secondary batteries.

Claims

1. A cover plate connected to a battery canister, the cover plate comprising: The main body seals the battery canister; An exhaust vent is formed in the main body and ruptures when the pressure inside the battery can exceeds a threshold. as well as A rupture induction section is formed in the main body while being spaced apart from the exhaust cut section, so that the exhaust cut section ruptures at a predetermined position.

2. The cover plate according to claim 1, wherein, At least one rigid reinforcement is formed in the main body, and The fracture-inducing portion is formed between multiple rigid reinforcement portions.

3. The cover plate according to claim 2, wherein, The rigidity reinforcement is configured to form a recessed groove in the main body portion on the inner side of the exhaust cut-out portion.

4. The cover plate according to claim 3, wherein, It has three grooves, and A fracture induction section is formed between two of the three grooves.

5. The cover plate according to claim 4, wherein, It forms three fracture-inducing regions, and A central portion is formed at the intersection of the three fracture induction portions to be linearly connected to each of the three fracture induction portions.

6. The cover plate according to claim 5, wherein, Each of the three fracture induction sections is spaced apart from the other at an angle of 120°.

7. The cover plate according to claim 3, wherein, The groove includes: The first part is formed inside the exhaust cut-out portion; The second part extends from one side of the first part toward the inside of the main body; The third part extends from the opposite side of the first part toward the inner side of the main body; and The fourth part connects the second part and the third part.

8. The cover plate according to claim 7, wherein, The exhaust cut includes a curve, and The first portion has a curve parallel to a portion of the curve of the exhaust cut portion.

9. The cover plate according to claim 7, wherein, The second part and the third part are formed in a linear shape.

10. The cover plate according to claim 9, wherein, The virtual extension lines of the second part and the virtual extension lines of the third part are formed to intersect each other.

11. The cover plate according to claim 7, wherein, The fourth part has a curve that is parallel to a portion of the curve of the first part.

12. A battery cell, the battery cell comprising: An electrode assembly, the electrode assembly including a positive electrode plate, a negative electrode plate and a diaphragm inserted between the positive electrode plate and the negative electrode plate; A battery can, the battery can being configured to house the electrode assembly within the battery can, and including an opening and a closing portion; as well as The cover plate according to any one of claims 1 to 10 is configured to seal the opening of the battery can.

13. The battery cell according to claim 12, further comprising: A sealing gasket, the sealing gasket being inserted between the edge of the cover plate and the opening of the battery can. The battery can includes: A rolled edge portion, formed by pressing the outer peripheral surface of the battery can inward; and A crimping portion extends and bends toward the inside of the battery can, such that the crimping portion and the sealing gasket are wrapped together to secure the edge of the cover.

14. A battery pack comprising at least one battery cell according to claim 12.

15. A vehicle comprising at least one battery cell according to claim 12.

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