Battery cell, battery pack and vehicle comprising battery pack

Abstract

A battery cell according to one embodiment of the present invention comprises: an electrode assembly comprising a first electrode, a second electrode, and a separator interposed between the first electrode and the second electrode; a battery case accommodating the electrode assembly through an opening formed on one side; an exhaust portion covering the opening and configured to break when an internal pressure of the battery case increases above a predetermined level; and a housing cover spaced apart from the exhaust portion by a predetermined distance in a radial direction and including a deformation inducing portion disposed radially inside the exhaust portion.

Description

Technical Field

[0001] The present disclosure relates to a battery cell, a battery pack, and a vehicle including the battery pack.

[0002] This application claims priority to Korean Patent Application No. 10-2022-0183384 filed on December 23, 2022 and Korean Patent Application No. 10-2023-0064622 filed on May 18, 2023, the disclosures of which are incorporated herein by reference. Background Art

[0003] Secondary batteries, which are easy to apply according to product groups and have electrical characteristics such as high energy density, are generally used in portable devices and electric vehicles (EVs) or hybrid electric vehicles (HEVs) driven by electric drive sources. These secondary batteries are attracting attention as new energy sources for improving eco-friendliness and energy efficiency because they have the main advantages of being able to significantly reduce the use of fossil fuels and not generating byproducts due to energy use.

[0004] Currently widely used secondary batteries include lithium-ion batteries, lithium polymer batteries, nickel-cadmium batteries, nickel-metal hydride batteries, nickel-zinc batteries, etc. The operating voltage of such a unit secondary battery cell (i.e., a unit battery cell) is about 2.5V to 4.5V. Therefore, when an output voltage higher than this voltage is required, a battery pack can be configured by connecting a plurality of battery cells in series. In addition, depending on the required charge / discharge capacity of the battery pack, the battery pack can be configured by connecting a plurality of battery cells in parallel. Therefore, the number of battery cells included in the battery pack can be set in various ways according to the required output voltage or charge / discharge capacity.

[0005] Furthermore, in the BDCR (Brim Roll / Crimp) structure of a cylindrical battery cell, the vent is used to reduce the internal pressure of the battery cell caused by gas by rupturing a notch provided in the vent during an increase in the internal pressure of the battery cell, thereby preventing a fire.

[0006] However, if the pressure inside the battery cell increases, the case cover bends so that a lift occurs between the case cover and the gasket surrounding the case cover, resulting in sliding of the case cover, thereby posing a risk of electrolyte or the like leaking from the battery cell.

[0007] However, if the thickness of the notch is gradually reduced to control the exhaust time, there is a problem of risks associated with processing efficiency and product safety. Summary of the invention

[0008] Technical issues

[0009] The present disclosure has been designed to solve the problems of the background art, and thus the present disclosure aims to minimize deformation of the shape of the case cover by providing a separate deformation inducing portion instead of the vent portion and preferentially inducing deformation of the deformation inducing portion.

[0010] On the other hand, the present disclosure aims to suppress the bending of the flat portion of the case cover by applying the deformation inducing portion, thereby ensuring the flatness of the case cover.

[0011] More specifically, the present disclosure is directed to preventing leakage of electrolyte due to sliding of a case cover by preventing a gap from being generated between the case cover and a gasket surrounding the case cover.

[0012] In another aspect, the present disclosure is directed to controlling the time of rupture of the vent portion by applying a deformation inducing portion.

[0013] However, the technical problems that the present disclosure seeks to solve are not limited to the above-mentioned problems, and other problems not mentioned above will be clearly understood by those skilled in the art from the description of the present invention described below.

[0014] Technical Solution

[0015] According to the present disclosure, a battery cell is provided, which includes: an electrode assembly, the electrode assembly including a first electrode, a second electrode and a separator interposed between the first electrode and the second electrode; a battery case, the battery case is configured to accommodate the electrode assembly through an opening formed on one side; and a vent portion and a case cover, the vent portion covering the opening and configured to break when the internal pressure of the battery case increases to above a predetermined level, the case cover being spaced apart from the vent portion by a predetermined distance in a radial direction and including a deformation inducing portion radially arranged inside the vent portion.

[0016] In one aspect of the present disclosure, the deformation inducing portion may be configured to induce the case cover to be preferentially deformed in a region where the deformation inducing portion is formed if the internal pressure of the battery case increases to a predetermined level or more.

[0017] In another aspect of the present disclosure, the deformation inducing portion may form a circular closed loop.

[0018] In another aspect of the present disclosure, the vent portion and the deformation inducing portion may be provided in a flat portion that is a central flat area of ​​the housing cover.

[0019] Preferably, the deformation inducing portion may be disposed inwardly from the exhaust portion in a radial direction.

[0020] In another aspect of the present disclosure, the deformation inducing portion may be provided in a region between a center point of the housing cover and a point corresponding to 70% of a radius of the housing cover.

[0021] Preferably, the deformation inducing portion may be provided in a region between a point corresponding to 20% of the radius of the housing cover and a point corresponding to 60% of the radius of the housing cover.

[0022] In another aspect of the present disclosure, a radial length between the deformation inducing portion and the exhaust portion may be 10% to 50% of a radial length of the housing cover.

[0023] In another aspect of the present disclosure, the deformation inducing portion may include at least one of an upper deformation inducing portion provided on an upper surface of the housing cover and a lower deformation inducing portion provided on a lower surface of the housing cover.

[0024] Preferably, the deformation inducing portion may include an upper deformation inducing portion provided on an upper surface of the housing cover and a lower deformation inducing portion provided on a lower surface of the housing cover.

[0025] In another aspect of the present disclosure, a thickness of the housing cover in a region where the deformation inducing portion is formed may be configured to be greater than a thickness of the housing cover in a region where the exhaust portion is formed.

[0026] In another aspect of the present disclosure, the upper deformation inducing portion and the lower deformation inducing portion may be disposed in a staggered state.

[0027] Furthermore, the present disclosure provides a battery pack including at least one battery cell according to the above-described embodiments.

[0028] Furthermore, the present disclosure provides a vehicle including at least one battery pack according to the above-described embodiments.

[0029] Beneficial Effects

[0030] According to the present disclosure, deformation of the shape of the case cover can be minimized by providing a separate deformation inducing portion instead of the vent portion and preferentially inducing deformation of the deformation inducing portion.

[0031] On the other hand, according to the present disclosure, the flatness of the case cover can be ensured by applying the deformation inducing portion to suppress the bending of the flat portion of the case cover.

[0032] More specifically, according to the present disclosure, it is possible to prevent leakage of electrolyte due to sliding of the case cover by preventing a gap from being generated between the case cover and a gasket surrounding the case cover.

[0033] On the other hand, according to the present disclosure, the time at which the vent portion is broken can be controlled by applying the deformation inducing portion.

[0034] However, effects obtainable from the present disclosure are not limited to the above-mentioned effects, and other effects not mentioned above will be clearly understood by those skilled in the art from the description of the present invention described below. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The accompanying drawings illustrate preferred embodiments of the present disclosure and, together with the detailed description of the present invention, serve to provide further understanding of the technical concept of the present disclosure, and therefore, the present disclosure is not to be construed as being limited to the accompanying drawings.

[0036] Figure 1 is a diagram illustrating a battery cell according to an embodiment of the present disclosure.

[0037] Figure 2 yes Figure 1 Longitudinal section and stereogram of the .

[0038] Figure 3 yes Figure 1 Longitudinal cross-section of a battery cell.

[0039] Figure 4 2 is a diagram illustrating a housing cover according to an embodiment of the present disclosure.

[0040] Figure 5 is a diagram illustrating a housing cover in a comparative example of the present disclosure.

[0041] Figure 6 is an example Figure 5 A diagram showing the process in which the housing cover receives pressure due to exhaust gas.

[0042] Figure 7 2 is a diagram illustrating a housing cover according to an embodiment of the present disclosure.

[0043] Figure 8 is an example Figure 7 A diagram showing the process in which the housing cover receives pressure due to exhaust gas.

[0044] Fig. 9 2 is a diagram illustrating a specific shape of a housing cover according to an embodiment of the present disclosure.

[0045] Fig.10 is a diagram illustrating a housing cover according to another embodiment of the present disclosure.

[0046] Fig.11 is a diagram illustrating a housing cover according to another embodiment of the present disclosure.

[0047] Fig.12 is a diagram illustrating a housing cover according to another embodiment of the present disclosure.

[0048] Fig.13: is a diagram illustrating the shape of a deformation inducing portion according to one embodiment of the present disclosure.

[0049] Fig.14 2 is a diagram illustrating the shape of a deformation inducing portion according to another embodiment of the present disclosure.

[0050] Fig.15 This is a table explaining the cross section of the 2D model to which the deformation inducing part is applied.

[0051] Fig.16 It is shown that through Fig.15 Table of experimental results of performing 2D static analysis on the model to confirm the deformation pattern of the exhaust section.

[0052] Fig.17 Examples include Figure 1 Diagram of a battery pack with battery cells in it.

[0053] Fig.18 Examples include Fig.17 Diagram of a battery pack in a vehicle. DETAILED DESCRIPTION

[0054] Hereinafter, the preferred embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. Before the description, it should be understood that the terms used in the specification and the appended claims should not be interpreted as limited to the general meaning and dictionary meaning, but are interpreted based on the meaning and concept corresponding to the technical aspects of the present disclosure based on the principle of allowing the inventor to appropriately define the terms for the best interpretation. Therefore, the configurations proposed in the embodiments of this specification and the accompanying drawings only represent the most preferred embodiments of the present disclosure, and do not represent all technical concepts of the present disclosure, so it should be understood that various equivalents and modifications may be made to them when submitting an application.

[0055] In addition, to help understand the present disclosure, the drawings are not drawn to true scale, and the sizes of some elements may be exaggerated. In addition, the same reference numerals may represent the same elements between different embodiments.

[0056] Stating that two objects being compared are the same means that they are "substantially the same". Thus, "substantially the same" can include situations with deviations that are considered low in the art, for example, deviations of less than 5%. In addition, a parameter that is uniform in a certain area can mean that it is uniform from an average point of view.

[0057] Although "first", "second", etc. are used to describe various elements, these elements are not limited to these terms. These terms are only used to distinguish one element from another element, and unless otherwise specified, the first element may also be the second element.

[0058] Throughout the specification, unless otherwise specified, a corresponding element may include a single element or a plurality of elements.

[0059] The configuration in which an element is disposed “on (or below)” or on the “top (or bottom)” of a target element may mean that the element may be disposed in contact with the upper surface (or lower surface) of the target element, or that another element may be interposed between the target element and the element disposed on the top (or bottom) of the target element.

[0060] In addition, the expression “an element is ‘connected’, ‘coupled’, or ‘fastened’ to another element” should be understood that these elements can be directly connected or fastened to each other, other elements can be “interposed” between these elements, or these elements can be “connected”, “coupled” or “fastened” through other elements.

[0061] Throughout the specification, unless otherwise specified, “A and / or B” may mean A or B or A and B, and “C to D” may mean “equal to or greater than C and equal to or less than D” unless otherwise specified.

[0062] For ease of explanation, in this specification, the longitudinal direction of the winding axis of the electrode assembly 10 wound into a winding core shape will be referred to as the "axial direction (Y)". In addition, the direction around the winding axis will be referred to as the "circumferential direction (X)". In addition, the direction approaching or away from the winding axis will be referred to as the "radial direction". Among them, the direction approaching the winding axis is referred to as the "centripetal direction", and the direction away from the winding axis is referred to as the "centrifugal direction".

[0063] Figure 1 is a diagram illustrating a battery cell 1 according to an embodiment of the present disclosure, and Figure 2 yes Figure 1 Longitudinal section and stereogram of the . Figure 3 yes Figure 1 A longitudinal cross-sectional view of a battery cell 1 in FIG.

[0064] Reference Figure 1 , a battery cell 1 according to an embodiment of the present disclosure includes an electrode assembly 10, a battery case 20, and a case cover 30. The battery cell 1 may further include a collector 40. The present disclosure is not limited to a specific type of battery and may be applied to other types of batteries such as square batteries.

[0065] Reference Figure 2 and Figure 3, the electrode assembly 10 includes a first electrode connector 11 and a second electrode connector 12. Specifically, the electrode assembly 10 includes a first electrode, a second electrode, and a separator inserted between the first electrode and the second electrode. The electrode assembly 10 has a structure in which the first electrode and the second electrode are wound around a winding axis while the separator is inserted between the first electrode and the second electrode, thereby defining a core and a peripheral surface. That is, the electrode assembly 10 applied to the present disclosure may be a core-wound electrode assembly 10. In this case, an additional separator may be provided on the peripheral surface of the electrode assembly 10 to insulate it from the battery case 20. The electrode assembly 10 may have a winding structure known in the art without limitation.

[0066] Furthermore, in the present disclosure, any active material known in the art may be used without limitation as the positive electrode active material coated on the positive electrode plate and the negative electrode active material coated on the negative electrode plate.

[0067] Reference Figure 1 and Figure 2 The battery case 20 is a substantially cylindrical container having an opening formed on one side thereof, and is made of a conductive metal material. Typically, the side surface of the battery case 20 and the bottom surface opposite to the opening are formed integrally. That is, the battery case 20 is typically configured so that its top in the height direction is open and the bottom is closed. The bottom surface of the battery case 20 may be configured in a substantially flat shape. The battery case 20 accommodates the electrode assembly 10 through an opening formed on one side in the height direction. The battery case 20 may also accommodate an electrolyte through the opening.

[0068] The battery case 20 may have a curling portion 21 formed at an end portion adjacent to an opening provided at the top of the battery case 20. The battery case 20 may also include a crimping portion 22 formed on the curling portion 21. The curling portion 21 may be configured so that the outer peripheral surface of the battery case 20 is press-fitted to a predetermined depth. More specifically, the curling portion 21 may be configured to be press-fitted inwardly in a region between an opening formed on one side of the battery case 20 and a receiving portion that receives the electrode assembly 10.

[0069] The beading portion 21 is formed above the electrode assembly 10. The inner diameter of the battery case 20 in the region where the beading portion 21 is formed is smaller than the diameter of the electrode assembly 10.

[0070] The curling portion 21 provides a support surface on which the housing cover 30 is placed. In addition, the curling portion 21 can provide a support surface on which at least a portion of the edge of the collector 40 is placed and connected. That is, at least a portion of the edge of the collector 40 of the present disclosure and / or the edge of the housing cover 30 can be placed on the upper surface of the curling portion 21. In order to stably support at least a portion of the edge of the collector 40 and / or the edge of the housing cover 30, the upper surface of the curling portion 21 can be configured to extend in a direction substantially parallel to the bottom surface of the battery housing 20 (i.e., in a direction substantially perpendicular to the side wall of the battery housing 20).

[0071] The beading portion 21 can prevent the electrode assembly 10 (which can have a size substantially corresponding to the inner diameter of the battery case 20) from coming out through the opening formed at the top of the battery case 20 and serve as a support portion on which the case cover 30 is placed. The upper beading portion 21 can serve as a support portion for fixing the collector 40, the sealing gasket G1, etc., and the case cover 30.

[0072] The crimping portion 22 is formed on the top of the beading portion 21. The crimping portion 22 is configured to extend and bend to surround the edge of the housing cover 30 disposed above the beading portion 21. Such a configuration of the crimping portion 22 can fix the housing cover 30 to the beading portion 21.

[0073] Reference Figures 1 to 3 , the housing cover 30 covers the opening formed on one side of the battery housing 20. The housing cover 30 can be fixed by a crimping portion 22 formed on the top of the battery housing 20. In this case, the sealing gasket G1 can be inserted between the battery housing 20 and the housing cover 30 and between the collector 40 and the housing cover 30 to improve the fixing force and airtightness of the battery housing 20. In this case, the contact portion 33a and / or the second contact portion can be inserted between the crimping portion 21 of the battery housing 20 and the sealing gasket G1. The contact portion 33a and / or the second contact portion inserted between the crimping portion 21 and the sealing gasket G1 as described above can be fixed by bending the crimping portion 22 extending upward from the crimping portion 21.

[0074] The housing cover 30 may have a substantially circular plate shape. More specifically, the housing cover 30 may include a flat portion as a central flat area, a flange portion as an area surrounded by a sealing gasket G1 and / or a crimping portion 22, and a connecting portion connecting the flat portion and the flange portion. The flat portion and the flange portion may be configured to be substantially parallel to the bottom surface of the battery housing 20. Here, the central axis direction position of the flat portion may be higher than the central axis direction position of the flange portion. Therefore, the connecting portion may have an inclined shape to connect the flat portion and the flange portion.

[0075] In addition, in the present disclosure, the case cover 30 is not a component that must be used as a current path. Therefore, as long as the battery case 20 and the case cover 30 are firmly fixed by welding or fixing with other parts to ensure the airtightness of the opening of the battery case 20, there is no need to apply the sealing gasket G1.

[0076] Reference Figures 1 to 3 The housing cover 30 includes a vent portion 31 and a deformation inducing portion 32 .

[0077] Reference Figures 1 to 3 , the vent portion 31 may be formed to prevent an increase in internal pressure due to gas generated inside the battery case 20. The vent portion 31 may be configured to break when the internal pressure of the battery case 20 increases to a predetermined level or higher. For example, the vent portion 31 may be formed in a portion of the case cover 30, and may be a region that is structurally more fragile than the surrounding region so as to be easily broken when internal pressure is applied thereto. For example, the vent portion 31 may be a region having a smaller thickness than the surrounding region.

[0078] That is, for some reason, a thermal event may occur inside the battery cell 1 to generate exhaust gas, and the pressure inside the battery case 20 may increase due to the exhaust gas. At this time, the vent portion 31 corresponding to the area that is structurally weaker than the surrounding area so as to be easily broken when the internal pressure of the battery cell 1 increases may be broken when the exhaust gas is generated.

[0079] Reference Figures 1 to 3 The deformation inducing portion 32 may be arranged to be spaced apart from the exhaust portion 31 by a predetermined distance in the radial direction. Figures 1 to 3 As shown, the deformation inducing portion 32 may be disposed radially inward from the vent portion 31. The deformation inducing portion 32 may be configured to deform if the internal pressure of the battery case 20 increases to a predetermined level or more. In particular, the deformation inducing portion 32 may be configured to induce the case cover 30 to deform preferentially in the region where the deformation inducing portion 32 is formed if the internal pressure of the battery case 20 increases to a predetermined level or more.

[0080] According to such a configuration, stress can be applied to deformation inducing portion 32 by exhaust gas generated inside battery cell 1, thereby causing deformation of deformation inducing portion 32. Therefore, shape deformation of exhaust portion 31 can be minimized. Therefore, deformation of the flange portion can be suppressed to prevent leakage of electrolyte and the like to the outside of battery cell 1.

[0081] Figure 4 is a diagram illustrating a housing cover 30 according to an embodiment of the present disclosure.

[0082] Reference Figures 1 to 4, the exhaust portion 31 may be configured to form a substantially circular closed loop. Therefore, if the exhaust gas is ejected from the inside of the battery cell 1 so that the internal pressure is applied to the case cover 30 in an upward direction, the exhaust portion 31 may be broken, and the inner area of ​​the circular closed loop of the case cover 30 may be ruptured. Therefore, exhaust can be effectively performed.

[0083] In addition, refer to Figures 1 to 4 , the deformation inducing portion 32 may be configured to form a substantially circular closed loop. Therefore, if the exhaust gas is ejected from the inside of the battery cell 1 so that the internal pressure is applied to the case cover 30 in an upward direction, the deformation inducing portion 32 may be deformed. At this time, since the deformation inducing portion 32 is configured to form an approximately circular closed loop, the deformation inducing portion 32 may be easily deformed.

[0084] In another aspect of the present disclosure, the vent portion 31 and the deformation inducing portion 32 may be provided in a flat portion that is a central flat area of ​​the housing cover 30 .

[0085] For example, refer to Figures 1 to 4 It can be seen that the deformation inducing portion 32 and the exhaust portion 31 are arranged in the flat portion of the housing cover 30 .

[0086] According to this structure, since the vent portion 31 is broken and the deformation inducing portion 32 is deformed and broken in the flat region, the deformation of the shape of the flange portion or the connection portion can be minimized. In particular, the flange portion can be prevented from being deformed from a shape substantially parallel to the bottom surface of the battery case 20 to an inclined shape. As a result, the deformation of the flange portion can be suppressed to prevent the electrolyte and the like from leaking out of the battery cell 1.

[0087] In another aspect of the present disclosure, the deformation inducing portion 32 may be disposed radially inward from the exhaust portion 31. Figure 5 and Figure 6 , and examples of embodiments of the present disclosure Figure 7 and Figure 8 This is described in detail.

[0088] Figure 5 is a diagram illustrating a housing cover 30 in a comparative example of the present disclosure, and Figure 6 is an example Figure 5 FIG. 3 is a diagram showing a process in which the housing cover 30 receives pressure due to exhaust gas. Figure 7 is a diagram illustrating a housing cover 30 according to an embodiment of the present disclosure, and Figure 8 is an example Figure 7 FIG. 1 is a diagram showing a process in which the housing cover 30 receives pressure due to exhaust gas.

[0089] Reference Figure 5 and Figure 6, the conventional case cover 30 includes only the vent portion 31 and does not include the deformation inducing portion 32. According to this structure, if the internal pressure of the battery cell 1 increases due to the exhaust gas generated inside the battery cell 1, stress is concentrated in the vent portion 31, resulting in fracture. However, in the process of rupture of the vent portion 31, the case cover 30 may bend upward under pressure, and at this time, as shown in FIG. Figure 6 As shown, it may become inclined in two directions based on the vent portion 31. Therefore, the connection portion and the flange portion are also affected, so that the connection portion and the flange portion are deformed to be inclined at a predetermined angle with the bottom surface of the battery case 20. In particular, when the flange portion is deformed to be inclined at a predetermined angle with the bottom surface of the battery case 20, a gap may be generated between the flange portion and the sealing gasket G1, which eventually causes the electrolyte and the like to leak out of the battery cell 1.

[0090] On the other hand, the housing cover 30 of the present disclosure includes a vent portion 31 and a deformation inducing portion 32 positioned to be spaced apart from the vent portion 31 by a predetermined distance in the radial direction. Figure 7 As shown, the deformation inducing portion 32 may be disposed inwardly from the exhaust portion 31 in the radial direction.

[0091] Reference Figure 7 , for example, the deformation inducing portion 32 may be configured to be recessed inward from the surface of the housing cover 30. For example, the deformation inducing portion 32 may be configured in the form of a groove or a notch. In addition, the recessed shape is not limited to a U-shape or a V-shape, and the scope of the present disclosure includes any structure that is recessed inward from the surface of the housing cover 30. In addition, the shape of the deformation inducing portion 32 is not limited to a groove or a notch, and the deformation inducing portion 32 of the present disclosure includes any configuration that is configured to be weaker than the surrounding area and more easily deformed than the surrounding area.

[0092] According to this structure, even if the internal pressure of the battery cell 1 increases, stress is applied not only to the vent portion 31 but also to the deformation inducing portion 32. Therefore, the shape of the deformation inducing portion 32 can be changed. In particular, in the case where the deformation inducing portion 32 is arranged inward from the vent portion 31 in the radial direction, the deformation inducing portion 32 can be mainly deformed. In other words, the configuration in which the deformation inducing portion 32 is arranged inward from the vent portion 31 in the radial direction can maximize the deformation of the deformation inducing portion 32. In other words, according to the present disclosure, since the deformation inducing portion 32 bends instead of the vent portion 31, the bending of the vent portion 31 can be suppressed. Therefore, deformation can be prevented in the surrounding area of ​​the vent portion 31 (especially, the flange portion). As a result, the flange portion is not deformed, thereby reducing the risk of leakage of electrolyte, etc.

[0093] Fig. 9 2 is a diagram illustrating a specific shape of the housing cover 30 according to the embodiment of the present disclosure.

[0094] In another aspect of the present disclosure, the deformation inducing portion 32 may be disposed in a region between a central point of the case cover 30 and a point corresponding to approximately 70% of a radius of the case cover 30 .

[0095] For example, according to the embodiments of the present disclosure Fig. 9 The housing cover 30 shown has a radius of about 21.6 mm, and the vent 31 is provided at a distance of about 14.9 mm from the center of the housing cover 30. The deformation inducing portion 32 is provided in a region between the center of the housing cover 30 and a point located at a distance of about 14.9 mm from the center. Converted into proportion, the vent 31 is provided at a point corresponding to about 70% of the radius of the housing cover 30 from the center of the housing cover 30, and the deformation inducing portion 32 is provided in a region between the center point of the housing cover 30 and a point corresponding to 70% of the radius of the housing cover 30. That is, according to the above configuration, the deformation inducing portion 32 can be provided inwardly from the vent 31 in the radial direction.

[0096] As described above, according to the structure in which the deformation inducing portion 32 is provided in the region between the center point of the housing cover 30 and the point corresponding to 70% of the radius of the housing cover 30, the flatness of the flange portion can be ensured compared to the case in which the deformation inducing portion 32 is provided outside the point corresponding to 70% of the radius of the housing cover 30. If the deformation inducing portion 32 is provided outside the above-mentioned point, the deformation inducing portion 32 is positioned outside the vent portion 31, so that the deformation inducing portion 32 can receive a greater stress than the vent portion 31. That is, since the deformation inducing portion 32 in which the deformation occurs is closer to the flange portion, the deformation of the flange portion may become more severe. In addition, since the stress applied to the deformation inducing portion 32 is greater than the stress applied to the vent portion 31, a fracture may occur in the deformation inducing portion 32 rather than in the vent portion 31. On the other hand, according to the present disclosure, since the deformation inducing portion 32 in which the deformation occurs is away from the flange portion, the deformation of the flange portion can be suppressed.

[0097] Preferably, the deformation inducing portion 32 may be disposed in a region between a point corresponding to about 20% of the radius of the housing cover 30 and a point corresponding to about 60% of the radius of the housing cover 30. That is, a radial length between the deformation inducing portion 32 and the exhaust portion 31 may be about 10% to 50% of the radial length of the housing cover 30.

[0098] For example, referring to the embodiment according to the present disclosure Fig. 9In the case of the housing cover 30 shown, in which the deformation inducing portion 32 is provided in a region between a point corresponding to about 20% of the radius of the housing cover 30 from the center of the housing cover 30 and a point corresponding to about 60% of the radius of the housing cover 30 from the center of the housing cover 30, the lowest exhaust pressure acting on the exhaust portion 31 can be obtained. In this case, the exhaust portion 31 can be provided at a point corresponding to about 70% of the radius of the housing cover 30 from the center of the housing cover 30, so that the radial length between the deformation inducing portion 32 and the exhaust portion 31 can be about 10% to 50% of the radial length of the housing cover 30.

[0099] More preferably, if the deformation inducing portion 32 is disposed in an area between a point corresponding to approximately 23% of the radius of the shell cover 30 from the center of the shell cover 30 and a point corresponding to approximately 46% of the radius of the shell cover 30 from the center of the shell cover 30, the exhaust pressure acting on the exhaust portion 31 can be ensured to be even lower.

[0100] That is, according to the present disclosure, the deformation of the area around the vent portion 31 can be minimized by separately providing the deformation inducing portion 32 instead of the vent portion 31 and inducing the deformation of the deformation inducing portion 32. That is, the leakage of the electrolyte due to the sliding of the flange portion can be suppressed. In addition, according to the present disclosure, the flatness of the housing cover 30 can be ensured by applying the deformation inducing portion 32 and suppressing the bending of the flat portion.

[0101] Furthermore, according to the present disclosure, the time at which the exhaust portion 31 is broken can be controlled using the deformation inducing portion 32. In other words, the exhaust pressure can be expected to be controlled by the dual structure of the exhaust portion 31 and the deformation inducing portion 32.

[0102] For reference, although a specific configuration of the shell cover 30 has been described in this specification by way of example to explain the embodiments of the present disclosure, the scope of the present disclosure is not limited to the specific configuration of the shell cover 30, and certainly includes other configurations of the shell cover 30 in which the exhaust portion 31 and / or the deformation inducing portion 32 are positioned with respect to each other in the same proportions as the above-mentioned embodiments.

[0103] Fig.10 is a diagram illustrating a housing cover 30 according to another embodiment of the present disclosure, and Fig.11 is a diagram illustrating a housing cover 30 according to another embodiment of the present disclosure.

[0104] Since the housing cover 30 according to the present embodiment is similar to the housing cover 30 in the previous embodiment, redundant descriptions of elements substantially the same as or similar to those in the previous embodiment will be omitted, and hereinafter, descriptions will be made based on differences therefrom.

[0105] According to one aspect of the present disclosure, the deformation inducing portion 32 may include at least one of an upper deformation inducing portion N1 disposed on an upper surface of the case cover 30 and a lower deformation inducing portion N2 disposed on a lower surface of the case cover 30 .

[0106] For example, the deformation inducing portion 32 may include only the upper deformation inducing portion N1 disposed on the upper surface of the housing cover 30, as shown in FIG. Fig.10 As another embodiment, the deformation inducing portion 32 may only include a lower deformation inducing portion N2 disposed on the lower surface of the housing cover 30, as shown in FIG. Fig.11 As another embodiment, the deformation inducing portion 32 may include an upper deformation inducing portion N1 disposed on the upper surface of the housing cover 30 and a lower deformation inducing portion N2 disposed on the lower surface of the housing cover 30. Figure 7 shown.

[0107] In the case where the deformation inducing portion 32 is provided on both surfaces of the housing cover 30, the exhaust pressure can be minimized. In addition, in the case where the deformation inducing portion 32 is provided only on the lower surface of the housing cover 30, the exhaust pressure can be maximized. As a result, the exhaust pressure according to the formation position of the deformation inducing portion 32 can be reduced as follows.

[0108] When deformation inducing portion 32 is provided only on the lower surface > When deformation inducing portion 32 is provided only on the upper surface > When deformation inducing portion 32 is provided on both surfaces.

[0109] In addition, if the exhaust pressure is low, gas discharge can be performed immediately after the thermal event occurs, which can be advantageous in terms of safety. In addition, if the gas discharge occurs immediately, the time required for the flange portion to deform is reduced, thereby minimizing the deformation of the flange portion. Therefore, the risk of leakage of electrolyte, etc. can be reduced. As a result, according to the present disclosure, the exhaust pressure can be adjusted by applying the deformation inducing portion 32. In addition, according to the present disclosure, the flatness of the flange portion can be ensured.

[0110] Fig.12 is a diagram illustrating a housing cover 30 according to another embodiment of the present disclosure.

[0111] In one aspect of the present disclosure, the thickness of the housing cover 30 in a region where the deformation inducing portion 32 is formed may be greater than the thickness of the housing cover 30 in a region where the vent portion 31 is formed.

[0112] For example, refer to Fig.12, the thickness of the region where the deformation inducing portion 32 is formed may be greater than the thickness of the region where the vent portion 31 is formed. Generally, the size of the notch (i.e., the thickness between the notches) may be adjusted to control the venting time. If the thickness between the notches is small, the vent portion 31 may break, and if the thickness between the notches is large, the vent portion 31 is less likely to break. Therefore, when the deformation inducing portion 32 is constructed, the rupture time may be controlled by adjusting the thickness between the notches.

[0113] According to the present disclosure, since the thickness of the region where deformation inducing portion 32 is formed is greater than the thickness of the region where vent portion 31 is formed, vent portion 31 may be broken more easily than deformation inducing portion 32. Therefore, even when pressure is generated due to exhaust gas, vent portion 31 is preferentially broken, and deformation inducing portion 32 is not preferentially broken.

[0114] Deformation inducing portion 32 may deform its shape before and after vent portion 31 breaks, thereby playing a role in controlling the breaking time of vent portion 31. For example, when stress acts on deformation inducing portion 32, the surrounding area of ​​deformation inducing portion 32 may be deformed from a flat shape to a curved shape based on deformation inducing portion 32. Therefore, the surrounding area of ​​deformation inducing portion 32 may be inclined in two directions relative to deformation inducing portion 32. That is, since the shape of deformation inducing portion 32 replaces the shape of vent portion 31 to be deformed, vent portion 31 may maintain its own shape, thereby suppressing the lifting of the flange portion. As a result, this can prevent the electrolyte and the like from leaking out of the battery cell 1.

[0115] Fig.13 is a diagram illustrating the shape of the deformation inducing portion 32 according to one embodiment of the present disclosure, and Fig.14 2 is a diagram illustrating the shape of a deformation inducing portion 32 according to another embodiment of the present disclosure.

[0116] Since the housing cover 30 according to the present embodiment is similar to the housing cover 30 in the previous embodiment, redundant descriptions of elements substantially the same as or similar to those in the previous embodiment will be omitted, and hereinafter, descriptions will be made based on differences therefrom.

[0117] Reference Fig.13 The deformation inducing portion 32 may include an upper deformation inducing portion N1 disposed on the upper surface of the housing cover 30 and a lower deformation inducing portion N2 disposed on the lower surface of the housing cover 30. As another embodiment of the present disclosure, Fig.14 As shown, the upper deformation inducing portion N1 and the lower deformation inducing portion N2 may be disposed in a staggered state.

[0118] according to Fig.14In the structure shown in the figure, since the upper deformation inducing portion N1 and the lower deformation inducing portion N2 are arranged in a staggered state, the shear stress may dominate in the area between the upper deformation inducing portion N1 and the lower deformation inducing portion N2. Fig.13 As shown, if the upper deformation inducing portion N1 and the lower deformation inducing portion N2 are arranged on the same line in the housing cover 30, tensile stress may dominate in the area between the upper deformation inducing portion N1 and the lower deformation inducing portion N2. Under the same pressure acting on the area between the upper deformation inducing portion N1 and the lower deformation inducing portion N2, deformation is more likely to occur when shear stress is applied than when tensile stress is applied. Therefore, according to the present disclosure, the deformation inducing portion 32 is easily deformed even if a lower exhaust pressure is applied. Alternatively, since the upper deformation inducing portion N1 and the lower deformation inducing portion N2 are in a staggered state, the same deformation amount can be ensured with a small forming amount. As a result, the reduction in the forming amount can reduce damage to the mold, so that the life of the housing cover 30 can be expected to increase.

[0119] Fig.15 is a table explaining a cross section of a 2D model to which the deformation inducing portion 32 is applied, and Fig.16 It is shown that through Fig.15 Table of experimental results of performing 2D static analysis to confirm the deformation pattern of the vent portion 31 using the model in FIG.

[0120] Fig.15 A cross section from the center of the housing cover 30 to one end thereof is shown in each case. Fig.15 The illustrated housing cover 30 has a radius of approximately 21.6 mm, and the vent 31 is provided at a distance of approximately 14.9 mm from the center of the housing cover 30. The deformation inducing portion 32 is provided in a region between the center of the housing cover 30 and a point located at a distance of approximately 14.9 mm from the center. Converted to proportion, the vent 31 is provided at a point corresponding to approximately 70% of the radius of the housing cover 30 from the center of the housing cover 30, and the deformation inducing portion 32 is provided in a region between the center point of the housing cover 30 and a point corresponding to 70% of the radius of the housing cover 30.

[0121] Reference Fig.15 and Fig.16 It was confirmed that the exhaust pressure was highest in the conventional housing cover 30 without the deformation inducing portion 32, and in the case where the deformation inducing portion 32 was provided in the region toward the center in the radial direction based on the exhaust portion 31, the exhaust pressure was lower.

[0122] That is, it can be seen from the above results that according to the present disclosure in which the deformation inducing portion 32 is applied, the exhaust pressure can be reduced. If the exhaust pressure is low, gas discharge can be performed immediately after the thermal event occurs, which can be advantageous in terms of safety. In addition, if the gas discharge occurs immediately, the time required for the flange portion to deform can be reduced, thereby minimizing the deformation of the flange portion. Therefore, the risk of leakage of electrolyte, etc. can be reduced. As a result, according to the present disclosure, the exhaust pressure can be adjusted by applying the deformation inducing portion 32. In addition, according to the present disclosure, the flatness of the flange portion can be ensured.

[0123] Reference Fig.15 and Fig.16 , more preferably, in the case where the deformation inducing portion 32 is provided between a point located at a distance of about 5 mm from the center of the housing cover 30 (a point corresponding to about 23% of the radius of the housing cover 30 from the center of the housing cover 30) and a point located at a distance of about 13 mm from the center of the housing cover 30 (a point corresponding to about 60% of the radius of the housing cover 30 from the center of the housing cover 30), it was confirmed that the exhaust pressure acting on the exhaust portion 31 was the lowest. In particular, in the case where the deformation inducing portion 32 is provided between a point located at a distance of about 5 mm from the center of the housing cover 30 (a point corresponding to about 23% of the radius of the housing cover 30 from the center of the housing cover 30) and a point located at a distance of about 10 mm from the center of the housing cover 30 (a point corresponding to about 46% of the radius of the housing cover 30 from the center of the housing cover 30), it was confirmed that the exhaust pressure acting on the exhaust portion 31 was even lower.

[0124] However, although the exhaust pressure acting on exhaust portion 31 is lowest in the case where deformation inducing portion 32 is provided at a point located at a distance of about 10 mm from the center of housing cover 30 in both directions (a point corresponding to about 46% of the radius of housing cover 30 from the center of housing cover 30), in this case, the maximum stress acts on deformation inducing portion 32, not on exhaust portion 31. That is, in this case, deformation inducing portion 32 may be broken. Therefore, it is important that exhaust portion 31 is provided at a position where the maximum stress occurs and deformation inducing portion 32 is provided within an appropriate range to reduce the exhaust pressure.

[0125] Reference Figure 1 and Figure 2 The collector 40 according to an embodiment of the present disclosure is accommodated inside the battery case 20, is electrically connected to the electrode assembly 10, and is also electrically connected to the battery case 20. That is, the collector 40 electrically connects the electrode assembly 10 and the battery case 20.

[0126] Fig.17 Examples include Figure 1 FIG. 3 shows a battery pack 3 of a battery cell 1 in FIG.

[0127] Reference Fig.17 The battery pack 3 according to the embodiment of the present disclosure includes a battery assembly in which a plurality of battery cells 1 according to the embodiment of the present disclosure as described above are electrically connected and a battery pack housing 2 accommodating the battery assembly. For ease of illustration, components such as bus bars for electrical connection, cooling units, and power terminals are omitted in the drawings of the present disclosure. That is, the battery pack 3 may also include elements of the battery pack 3 such as a BMS, a battery pack housing, a relay, a current sensor, etc., which are known at the time of filing the present disclosure.

[0128] Fig.18 Examples include Fig.17 FIG. 5 is a diagram of a vehicle 5 having a battery pack 3 in the vehicle.

[0129] Reference Fig.18 The vehicle 5 according to the embodiment of the present disclosure may be, for example, an electric vehicle, a hybrid electric vehicle, or a plug-in hybrid electric vehicle, and includes the battery pack 3 according to the embodiment of the present disclosure. The vehicle 5 includes a four-wheel vehicle and a two-wheel vehicle. The vehicle 5 operates by receiving power from the battery pack 3 according to the embodiment of the present disclosure. In addition to the battery pack 3, the vehicle 5 according to the present disclosure may further include various other elements included in the vehicle 5. For example, in addition to the battery pack 3 according to the present disclosure, the vehicle 5 according to the present disclosure may further include a vehicle body, a motor, a control device such as an electronic control unit (ECU), and the like.

[0130] According to the various embodiments described above, even if gas discharge occurs due to an abnormality in the battery cell 1, the present disclosure can minimize the deformation of the area around the vent portion 31 by applying the deformation inducing portion 32. In other words, electrolyte leakage due to sliding of the flange portion can be suppressed. In addition, according to the present disclosure, the flatness of the housing cover 30 can be ensured by suppressing the bending of the flat portion by applying the deformation inducing portion 32. Furthermore, according to the present disclosure, the deformation inducing portion 32 can be used to control the time when the vent portion 31 is broken. In other words, the exhaust pressure can be expected to be controlled by the double-notch structure of the vent portion 31 and the deformation inducing portion 32.

[0131] Furthermore, although terms indicating directions such as up and down are used in the present specification, it is obvious to those skilled in the art that these terms are merely for convenience of explanation and may vary depending on the position of a target object or the position of an observer.

[0132] As described above, although the present disclosure has been described with reference to limited embodiments and drawings, the present disclosure is not limited thereto, and various modifications and variations are possible within the technical concept of the present disclosure and within the equivalent scope of the appended claims by those skilled in the art to which the present disclosure belongs.

[0133] [Description of Reference Signs]

[0134] 5: Vehicles

[0135] 3: Battery Pack

[0136] 2: Battery pack housing

[0137] 1: Battery Cell

[0138] 10: Electrode assembly

[0139] 11: First uncoated portion

[0140] 12: Second uncoated portion

[0141] H1: Winding hole

[0142] 20: Battery housing

[0143] 21: Curling part

[0144] 22: Crimping part

[0145] 30: Shell cover

[0146] 31: Exhaust

[0147] 32: Deformation induction part

[0148] N1: Upper deformation induction part

[0149] N2: Lower deformation induction part

[0150] G1: Sealing gasket

[0151] 40: Collector

[0152] H2: Collector hole

Claims

1. A battery cell, comprising: an electrode assembly, the electrode assembly comprising a first electrode, a second electrode, and a separator interposed between the first electrode and the second electrode; a battery case configured to accommodate the electrode assembly through an opening formed on one side; as well as A vent portion and a housing cover, wherein the vent portion covers the opening and is configured to break when the internal pressure of the battery housing increases to above a predetermined level, the housing cover is spaced apart from the vent portion by a predetermined distance in a radial direction and includes a deformation inducing portion radially arranged inside the vent portion.

2. The battery cell according to claim 1, in, The deformation inducing portion is configured to induce the case cover to be deformed preferentially in a region where the deformation inducing portion is formed if the internal pressure of the battery case increases to a predetermined level or more.

3. The battery cell according to claim 1, in, The deformation inducing portion forms a circular closed loop.

4. The battery cell according to claim 1, in, The exhaust portion and the deformation inducing portion are provided in a flat portion which is a central flat region of the housing cover.

5. The battery cell according to claim 1, in, The deformation inducing portion is provided in a region between a center point of the housing cover and a point corresponding to 70% of a radius of the housing cover.

6. The battery cell according to claim 1, in, The deformation inducing portion is provided in a region between a point corresponding to 20% of the radius of the housing cover and a point corresponding to 60% of the radius of the housing cover.

7. The battery cell according to claim 1, in, A radial length between the deformation inducing portion and the exhaust portion is 10% to 50% of a radial length of the housing cover.

8. The battery cell according to claim 1, in, The deformation inducing portion includes at least one of an upper deformation inducing portion provided on an upper surface of the housing cover and a lower deformation inducing portion provided on a lower surface of the housing cover.

9. The battery cell according to claim 1, in, The deformation inducing portion includes an upper deformation inducing portion provided on an upper surface of the housing cover and a lower deformation inducing portion provided on a lower surface of the housing cover.

10. The battery cell according to claim 1, in, A thickness of the housing cover in a region where the deformation inducing portion is formed is greater than a thickness of the housing cover in a region where the exhaust portion is formed.

11. The battery cell according to claim 9, in, The upper deformation inducing portion and the lower deformation inducing portion are arranged in a staggered state.

12. A battery pack comprising at least one battery cell according to any one of claims 1 to 11.

13. A vehicle comprising at least one battery pack according to claim 12.

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