Secondary battery

Abstract

The present disclosure relates to a secondary battery. Such a secondary battery comprises a case having one side open and a receiving space formed inside, an electrode assembly including a positive electrode and a negative electrode and a separator disposed between the positive electrode and the negative electrode, and a cap assembly coupled to the case to seal the receiving space and including a positive terminal electrically connected to the positive electrode and a negative terminal electrically connected to the negative electrode, wherein a vent hole is formed in the case or the cap assembly and a vent that breaks when the pressure in the receiving space exceeds a preset reference pressure is coupled to the vent hole, and the vent may include a notch portion formed by a groove having a first shape on at least a part of one side facing the receiving space or another side opposite to the one side, and a bending prevention portion formed by a recess having a second shape on at least a part of the other side.

Description

Technology Field

[0001] The present disclosure relates to a secondary battery, and more specifically, to a secondary battery having a vent that can be opened to have a required opening area. Background Technology

[0003] Among battery cells, rechargeable secondary batteries are used in small portable electronic devices such as mobile phones or camcorders, or multiple units are connected to serve as a power source for drive motors in hybrid vehicles.

[0004] These secondary batteries are manufactured in various shapes, such as rigid prismatic or cylindrical shapes, or flexible pouch shapes.

[0005] Meanwhile, due to the nature of product categories to which secondary batteries are applied, safety requirements are becoming increasingly high. In particular, in the case of electric vehicles equipped with multiple secondary batteries, there is a need to prevent a fire originating from one secondary battery from spreading to adjacent secondary batteries, causing a chain reaction of fires and resulting in thermal runaway of the secondary batteries.

[0006] To prevent such thermal runaway phenomena, secondary batteries are sometimes equipped with vents. The vent is formed as a plate-shaped component that blocks a hole formed in the battery case; when the internal pressure of the secondary battery rises above a preset pressure, the plate-shaped component ruptures to form an opening, thereby releasing the internal gas to the outside.

[0007] Meanwhile, in order to effectively vent gas inside the secondary battery to the outside, the opening formed by the rupture of the vent must have a required area, but as the plate-shaped member bends during the process of the vent rupture, the opening may have a size smaller than the required size.

[0008] As such, if the opening formed by the rupture of the vent is smaller than the required size, it may not be possible to effectively discharge gas from inside the secondary battery to the outside, and it may not be possible to effectively prevent fire in the secondary battery or thermal runaway of the secondary battery.

[0009] Therefore, it is necessary to develop a secondary battery equipped with a vent that can be broken so that the opening formed when the vent breaks has the required size. The problem to be solved

[0011] One objective of the present disclosure is to provide a secondary battery having a vent that can be broken to form an opening having a required size.

[0012] Another objective of the present disclosure is to provide a secondary battery in which the occurrence of fire can be effectively prevented.

[0013] The secondary battery of the present disclosure can be widely applied in green technology fields utilizing batteries, such as electric vehicles. Furthermore, the secondary battery of the present disclosure can be used in eco-friendly electric vehicles, hybrid vehicles, etc., to prevent climate change by suppressing air pollution and greenhouse gas emissions. means of solving the problem

[0015] As a technical means for solving the above-mentioned technical problem, a secondary battery according to one embodiment of the present disclosure comprises: a case having one side open and a receiving space formed inside; an electrode assembly including a positive electrode, a negative electrode, and a separator disposed between the positive electrode and the negative electrode, which is received in the receiving space; and a cap assembly coupled to the case to seal the receiving space and including a positive terminal electrically connected to the positive electrode and a negative terminal electrically connected to the negative electrode, wherein a vent hole is formed in the case or the cap assembly, and a vent that breaks when the pressure of the receiving space exceeds a preset reference pressure is coupled to the vent hole, and the vent may include a notch portion formed by a groove having a first shape on at least a part of one side facing the receiving space or another side opposite to the one side, and a bending prevention portion formed by a recess having a second shape on at least a part of the other side.

[0016] As a technical means for solving the above-mentioned technical problem, a secondary battery according to another embodiment of the present disclosure comprises: a case having one side and another side open and a receiving space formed inside; an electrode assembly including a positive electrode and a negative electrode and a separator disposed between the positive electrode and the negative electrode, which is received in the receiving space; a first cap assembly including a positive terminal coupled to one side of the case and electrically connected to the positive electrode; and a second cap assembly including a negative terminal coupled to the other side of the case and electrically connected to the negative electrode. A vent hole is formed in the case, the first cap assembly, or the second cap assembly, and a vent that breaks when the pressure of the receiving space becomes greater than a preset reference pressure is coupled to the vent hole. The vent may include a notch portion formed by a groove having a first shape on at least a part of one side facing the receiving space or another side opposite to the one side, and a bending prevention portion formed by a recess having a second shape on at least a part of the other side.

[0017] Additionally, the vent is formed by extending in the longitudinal direction, and the notch portion includes a first groove formed by extending in a direction parallel to the longitudinal direction, and the first groove may be formed to pass through the center of the vent, which is the midpoint between one end in the longitudinal direction and the other end in the longitudinal direction of the vent, and the midpoint between one end in the vertical direction and the other end in the vertical direction of the vent.

[0018] Additionally, the bending prevention member may include a first emboss formed between the first groove and one end of the vertical direction of the vent, and a second emboss formed between the first groove and the other end of the vertical direction of the vent.

[0019] Additionally, the first embossing may include a first inclined surface located adjacent to the first groove, with one side connected to the other side of the vent, and a second inclined surface located further from the first groove than the first inclined surface, with one side connected to the other side of the first inclined surface and the other side connected to the other side of the vent. The second embossing may include a third inclined surface located adjacent to the first groove, with one side connected to the other side of the vent, and a fourth inclined surface located further from the first groove than the third inclined surface, with one side connected to the third inclined surface and the other side connected to the other side of the vent.

[0020] In addition, the distance between one side of the first inclined surface and the other side of the second inclined surface may be different, and the distance between one side of the third inclined surface and the other side of the fourth inclined surface may be different.

[0021] Additionally, the angle formed by the first inclined surface and the plane parallel to the other side of the vent, or the angle formed by the second inclined surface and the plane, may be 90 degrees, and the angle formed by the third inclined surface and the plane, or the angle formed by the fourth inclined surface and the plane, may be 90 degrees.

[0022] In addition, the first emboss and the second emboss may be formed parallel to the first groove.

[0023] Additionally, the first emboss may be formed such that the vertical distance between the first emboss and the center of the vent is the shortest among the vertical distances between the first emboss and the first groove, and the second emboss may be formed such that the vertical distance between the second emboss and the center of the vent is the shortest among the vertical distances between the second emboss and the first groove.

[0024] Additionally, the first embossment may be formed such that the vertical distance between the first embossment and the first groove increases as one end in the longitudinal direction and the other end in the longitudinal direction of the vent from the center of the vent, and the second embossment may be formed such that the vertical distance between the second embossment and the first groove increases as one end in the longitudinal direction and the other end in the longitudinal direction of the vent from the center of the vent.

[0025] Additionally, the notch portion may further include a second groove formed adjacent to the outer circumference of one end in the longitudinal direction of the vent and a third groove formed adjacent to the outer circumference of the other end in the longitudinal direction of the vent.

[0026] Additionally, the second groove may be connected to the first groove and formed parallel to the outer circumference of one end in the longitudinal direction of the vent, and the third groove may be connected to the first groove and formed parallel to the outer circumference of the other end in the longitudinal direction of the vent.

[0027] Additionally, the first emboss is formed such that the shortest distance between the vertical end of the vent and the second groove is equal to the shortest distance between the vertical end of the vent and the longitudinal end of the first emboss, and the shortest distance between the vertical end of the vent and the third groove is equal to the shortest distance between the vertical end of the vent and the other longitudinal end of the first emboss, and the second emboss is formed such that the shortest distance between the vertical end of the vent and the second groove is equal to the shortest distance between the vertical end of the vent and the longitudinal end of the second emboss, and the shortest distance between the vertical end of the vent and the third groove is equal to the distance between the vertical end of the vent and the other longitudinal end of the third emboss It can be formed so that the shortest distance becomes the same.

[0028] In addition, the first emboss and the second emboss may be formed symmetrically with respect to the first groove, and the second groove and the third groove may be formed symmetrically with respect to the center of the vent.

[0029] Specific details of other embodiments for solving the problem are included in the description of the invention and the drawings. Effects of the invention

[0031] According to one embodiment of the present disclosure described above, the secondary battery according to the present disclosure provides the effect that the opening for gas discharge can be formed to have the required size by providing a bending prevention member when the vent is broken to form an opening for gas discharge.

[0032] In addition, it enables the effective discharge of gas, thereby providing the effect of effectively preventing fires. Brief explanation of the drawing

[0034] FIG. 1 is a perspective view of a secondary battery according to one embodiment of the present disclosure. Figure 2 is a cross-sectional view of a secondary battery. Figure 3 is a plan view of the vent. FIG. 4 is a plan view of a vent having a second groove and a third groove formed parallel to the outer circumference of the vent. FIG. 5 is a cross-sectional view of an embossed vent having an inclined surface, viewed along the longitudinal direction. Figure 6 is a graph showing the relative values ​​of the bending moment of the embo according to the length of the inclined plane. FIG. 7 is a cross-sectional view along the longitudinal direction of a vent having an embossed surface formed such that the angle formed with a plane parallel to the other side of the vent is 90 degrees. Figure 8 is a graph showing the relative values ​​of the bending moment of the embo according to the angle formed by the plane parallel to the other side of the vent and the inclined plane. FIG. 9 is a plan view of a vent having an embossed shape formed such that the distance from the first groove increases as it moves away from the center of the vent. FIG. 10 is a perspective view of a secondary battery according to another embodiment of the present disclosure. Specific details for implementing the invention

[0035] Embodiments of the present invention are described below with reference to the attached drawings to enable those skilled in the art to easily implement the invention. However, the present invention may be embodied in various different forms and is not limited to the embodiments described herein. Furthermore, in order to clearly explain the present invention in the drawings, parts unrelated to the explanation have been omitted, and similar parts throughout the specification are denoted by similar reference numerals.

[0036] Throughout this specification, when a part is described as being "connected" to another part, this includes not only cases where they are "directly connected," but also cases where they are "electrically connected" with other elements interposed between them.

[0037] Throughout this specification, when a component is described as being located “on” another component, this includes not only cases where a component is in contact with another component, but also cases where another component exists between the two components.

[0038] Throughout this specification, when a part is described as "comprising" a certain component, this means that, unless specifically stated otherwise, it does not exclude other components but may include additional components. Throughout this specification, terms of degree such as "about," "substantially," etc., are used to mean at or near the stated value when inherent manufacturing and material tolerances are presented in the said meaning, and are used to prevent unscrupulous infringers from unfairly exploiting the disclosure in which precise or absolute values ​​are mentioned to aid in understanding this specification. Throughout this specification, terms of degree such as "step of" or "step of" do not mean "step for."

[0039] Preferred embodiments of the present disclosure will be described in detail below with reference to the attached drawings and the contents described below. However, the present disclosure is not limited to the embodiments described herein and may be embodied in other forms. Throughout the specification, the same reference numerals indicate the same components.

[0040] Hereinafter, a secondary battery according to one embodiment of the present disclosure will be described.

[0041] FIG. 1 is a perspective view of a secondary battery according to one embodiment of the present disclosure.

[0042] Referring to FIG. 1, the secondary battery (1) includes a case (100), a cap assembly (500), and a vent (600).

[0043] Figure 2 is a cross-sectional view of a secondary battery.

[0044] And, referring to FIG. 2, the secondary battery (1) further includes an electrode assembly (200), a positive plate (300), and a negative plate (400).

[0045] First, the case (100) is described.

[0046] Referring to FIG. 2, the case (100) has one side open and can have a receiving space formed inside.

[0047] And, a vent hole can be formed in the case (100).

[0048] Such a case (100) can form the exterior of a secondary battery (1), and depending on its shape, it can be formed in a rectangular shape, a pouch shape, etc., but the configuration of the case (100) is not limited thereto.

[0049] Next, the electrode assembly (200) will be described.

[0050] The electrode assembly (200) is accommodated in a receiving space and may include a positive electrode (210) and a negative electrode (230), and a separator (220) disposed between the positive electrode (210) and the negative electrode (230).

[0051] The positive electrode (210) can be formed by applying a positive electrode active material, such as a transition metal oxide, to a positive electrode current collector formed of a metal foil such as aluminum.

[0052] And, the positive electrode (210) includes a positive electrode-free area, which is an area where the positive electrode active material is not applied, and the positive electrode-free area can serve as a passage for current flow between the positive electrode and the outside and can also form a positive electrode tab.

[0053] The negative electrode (230) can be formed by applying a negative active material, such as graphite or carbon, to a negative current collector formed of a metal foil such as copper or nickel.

[0054] And, the cathode (230) includes a cathode-free area, which is an area where the cathode active material is not applied, and the cathode-free area can serve as a passage for current flow between the cathode (230) and the outside and can also form a cathode tab.

[0055] The separator (220) is positioned between the positive electrode (210) and the negative electrode (230) to prevent short circuits and enable the movement of lithium ions. This separator may be made of polyethylene, polypropylene, or a composite film of polyethylene and polypropylene.

[0056] A plurality of positive electrodes (210) and a plurality of negative electrodes (230) formed in this manner can be alternately stacked with a separator (220) in between to form an electrode assembly (200), and the electrode assembly (200) can be accommodated in the receiving space of the case (100) together with the electrolyte.

[0057] Next, the positive plate (300) will be explained.

[0058] Referring to FIG. 2, the positive plate (300) can be electrically connected to the positive plate (210).

[0059] Specifically, the positive plate (300) can be electrically connected by being combined with the positive non-positive portion or positive tab of the positive (210). At this time, the positive plate (300) may be made of copper or a copper alloy, but the composition of the positive plate (300) is not limited thereto.

[0060] Next, the negative plate (400) will be explained.

[0061] Referring to FIG. 2, the negative plate (400) can be electrically connected to the negative electrode (230).

[0062] Specifically, the cathode plate (400) can be electrically connected by being coupled to the cathode-free portion or cathode tab of the cathode (230). At this time, the cathode plate (400) may be manufactured of aluminum or an aluminum alloy, but the composition of the cathode plate (400) is not limited thereto.

[0063] Next, the cap assembly (500) will be described.

[0064] Referring to FIG. 2, the cap assembly (500) is coupled to the case (100) to seal the receiving space and includes a positive terminal (510) electrically connected to the positive electrode (210) and a negative terminal (520) electrically connected to the negative electrode (230), and a vent hole may be formed.

[0065] At least one vent hole may be formed in the case (100) or the cap assembly (500), but it is preferable that only one vent hole be formed in the secondary battery (1).

[0066] Specifically, if a vent hole is formed in the cap assembly (500), a vent hole may not be formed in the case (100), and if a vent hole is formed in the case (100), a vent hole may not be formed in the cap assembly (500). That is, a vent hole may be formed in the case (100) or the cap assembly (500).

[0067] The positive terminal (510) can be formed of metal and electrically connected to the positive plate (300).

[0068] In this way, by electrically connecting the positive terminal (510) to the positive plate (300), the positive terminal (510) can be electrically connected to the positive (210).

[0069] The negative terminal (520) is formed of metal and can be electrically connected to the negative plate (400).

[0070] In this way, by electrically connecting the negative terminal (520) to the negative plate (400), the negative terminal (520) can be electrically connected to the negative (230).

[0071] The vent hole can be configured as a hole to connect the receiving space with the outside of the receiving space.

[0072] A vent (600), which will be described later, can be coupled to these vent holes to seal the receiving space.

[0073] Meanwhile, the cap assembly (500) may have an injection port (530) formed therein for injecting an electrolyte into the receiving space, and the injection port (530) may be fitted with a stopper or the like to seal the receiving space.

[0074] Next, the vent (600) will be explained.

[0075] Referring to FIG. 2, the vent (600) is a member that blocks a vent hole formed in the case (100) of a secondary battery (1), is coupled to the vent hole, and can be broken when the pressure in the receiving space becomes greater than a preset reference pressure.

[0076] Figure 3 is a plan view of the vent.

[0077] Such a vent (600) may include a notch (610) and a bending prevention part (620), as shown in FIG. 3.

[0078] The notch (610) can perform the function of opening the vent (600) by breaking when pressure is applied from the receiving space to the vent (600).

[0079] Such notch portions (610) may be formed by creating a groove to have a first shape on at least a part of one side of the vent (600) facing the receiving space or on the other side opposite to the one side.

[0080] For example, as illustrated in FIG. 3, the notch portion (610) may include a first groove (611), a second groove (612), and a third groove (613) formed on the other side of the vent (600).

[0081] Specifically, the vent (600) may be formed by extending in the longitudinal direction, and the notch portion (610) may include a first groove (611) formed by extending in a direction parallel to the longitudinal direction.

[0082] The first groove (611) may be composed of a groove in which at least a portion of the surface of the vent (600) is recessed, and may be configured to break when a force of a predetermined size is applied.

[0083] At this time, the first groove (611) can be formed in the vent (600) so that the vent (600) can be broken more effectively when pressure is applied from the receiving space.

[0084] For example, the first groove (611) may be formed to pass through the center of the vent (600), which is the midpoint between one end in the longitudinal direction of the vent (600) and the other end in the longitudinal direction, and the midpoint between one end in the vertical direction of the vent (600) and the other end in the vertical direction.

[0085] That is, the first groove (611) can be formed to pass through the center of the vent (600).

[0086] The second groove (612) may be composed of a groove in which at least a portion of the surface of the vent (600) is recessed, and may be configured to break when a force of a predetermined size is applied.

[0087] This second groove (612) can be broken together with the first groove (611) and can be formed adjacent to the outer circumference of one end in the longitudinal direction of the vent (600) as shown in FIG. 3.

[0088] At this time, the second groove (612) can be formed in the vent (600) so that when the vent (600) receives pressure from the receiving space and the first groove (611) breaks, the second groove (612) can be easily broken together with the first groove (611).

[0089] FIG. 4 is a plan view of a vent having a second groove and a third groove formed parallel to the outer circumference of the vent.

[0090] For example, as illustrated in FIG. 4, the second groove (612) is connected to the first groove (611) and can be formed parallel to the outer circumference of one end of the longitudinal direction of the vent (600).

[0091] The third groove (613) may be composed of a groove in which at least a portion of the surface of the vent (600) is recessed, and may be configured to break when a force of a predetermined size is applied.

[0092] This third groove (613) can be broken together with the first groove (611) and can be formed adjacent to the outer circumference of the other end of the longitudinal direction of the vent (600) as shown in FIG. 3.

[0093] At this time, the third groove (613) can be formed in the vent (600) so that when the vent (600) receives pressure from the receiving space and the first groove (611) breaks, the third groove (613) can be easily broken together with the first groove (611).

[0094] For example, as illustrated in FIG. 4, the third groove (613) is connected to the first groove (611) and can be formed parallel to the outer circumference of the other end of the longitudinal direction of the vent (600).

[0095] The bending prevention part (620) can perform the function of preventing the vent (600) from bending when the notch part (610) is broken and the vent (600) is opened.

[0096] This bending prevention part (620) may be formed by being recessed so that at least a portion of the other side of the vent (600) has a second shape.

[0097] This anti-bending part (620) may include a first emboss (621) and a second emboss (622), as shown in FIG. 3.

[0098] Next, the first embo (621) is described.

[0099] The first emboss (621) can be formed between the first groove (611) and one end of the vertical direction of the vent (600).

[0100] FIG. 5 is a cross-sectional view of an embossed vent having an inclined surface, viewed along the longitudinal direction.

[0101] As illustrated in FIG. 5, the first embo (621) may include a first inclined surface (621-1) which is connected to the other side of the vent (600) and located adjacent to the first groove (611), and a second inclined surface (621-2) which is connected to the other side of the first inclined surface (621-1) and is connected to the other side of the vent (600) and located further from the first groove (611) than the first inclined surface (621-1).

[0102] At this time, the first inclined surface (621-1) and the second inclined surface (621-2) of the first embo (621) can be formed to effectively prevent the first embo (621) from bending, thereby effectively preventing the vent (600) from bending.

[0103] Specifically, the first inclined surface (621-1) and the second inclined surface (621-2) may be formed such that the distance between one side of the first inclined surface (621-1) and the distance between one side of the second inclined surface (621-2) and the other side are different.

[0104] That is, the first embo (621) can be formed such that the two sides are not symmetrical with respect to the groove.

[0105] Figure 6 is a graph showing the relative values ​​of the bending moment of the embo according to the length of the inclined plane.

[0106] The graph in FIG. 6 shows the result of measuring the relative value of the bending moment of the first embo (621) while varying the length of the second inclined surface (621-2) between 0.2 mm and 0.7 mm when the length of the first inclined surface (621-1) is 0.2 mm.

[0107] As shown in the graph of Fig. 6, the bending moment of the first embo (621) increases when the lengths of the first inclined surface (621-1) and the second inclined surface (621-2) are different from when the lengths of the first inclined surface (621-1) and the second inclined surface (621-2) are the same.

[0108] That is, when the lengths of the first inclined surface (621-1) and the second inclined surface (621-2) are different, the bending moment of the first embo (621) increases, and the bend (600) including the first embo (621) can be effectively prevented from bending.

[0109] Additionally, the first inclined surface (621-1) and the second inclined surface (621-2) of the first embo (621) may be formed to more effectively prevent the first embo (621) from bending, thereby more effectively preventing the vent (600) from bending.

[0110] FIG. 7 is a cross-sectional view along the longitudinal direction of a vent having an embossed surface formed such that the angle formed with a plane parallel to the other side of the vent is 90 degrees.

[0111] Specifically, as illustrated in FIG. 7, the first inclined surface (621-1) and the second inclined surface (621-2) may be formed such that the angle formed by the first inclined surface (621-1) and the plane (630) parallel to the other side of the vent (600), or the angle formed by the second inclined surface (621-2) and the plane (630), is 90 degrees.

[0112] That is, the first inclined surface (621-1) and the second inclined surface (621-2) may have different lengths, and can be formed such that the angle formed by either one with the plane (630) is a right angle.

[0113] Figure 8 is a graph showing the relative values ​​of the bending moment of the embo according to the angle formed by the plane parallel to the other side of the vent and the inclined plane.

[0114] The graph in FIG. 8 shows the result of measuring the relative value of the bending moment of the first embo (621) while changing the angle formed by the first inclined surface (621-1) and the plane (630) when the lengths of the first inclined surface (621-1) and the second inclined surface (621-2) are different from each other.

[0115] As shown in the graph of FIG. 8, as the angle formed by the first inclined surface (621-1) and the plane (630) approaches 90 degrees, the bending moment of the first embo (621) increases.

[0116] That is, as the angle formed by the first inclined surface (621-1) and the flat surface (630) approaches 90 degrees, the bending moment of the first embo (621) increases, and the bend (600) including the first embo (621) can be prevented from bending more effectively.

[0117] Likewise, as the angle formed by the second inclined surface (621-2) and the plane (630) approaches 90 degrees, the bending moment of the first embo (621) increases, and the bend (600) containing the first embo (621) may be more effectively prevented from bending.

[0118] Meanwhile, the first embo (621) can be formed to have various shapes formed along the length direction of the vent (600).

[0119] For example, as illustrated in FIG. 3, the first emboss (621) can be formed parallel to the first groove (611).

[0120] FIG. 9 is a plan view of a vent having an embossed shape formed such that the distance from the first groove increases as it moves away from the center of the vent.

[0121] To explain another example, as illustrated in FIG. 9, the first emboss (621) can be formed such that the vertical distance between the first emboss (621) and the center of the vent (600) is the shortest among the vertical distances between the first emboss (621) and the first groove (611).

[0122] And, as shown in FIG. 9, the first emboss (621) can be formed such that the vertical distance between the first emboss (621) and the first groove (611) increases as it goes from the center of the vent (600) to one end in the longitudinal direction and to the other end in the longitudinal direction of the vent (600).

[0123] At this time, the first emboss (621) may be formed in a shape that can more effectively prevent the vent (600) from bending when the second groove (612) and the third groove (613) of the notch portion (610) are broken.

[0124] Specifically, referring to FIG. 9, the first embo (621) can be formed such that the shortest distance (L1) between the vertical end of the vent (600) and the second groove (612) and the shortest distance (L2) between the vertical end of the vent (600) and the longitudinal end of the first embo (621) are equal.

[0125] And, the first embo (621) can be formed such that the shortest distance (L3) between one end of the vertical direction of the vent (600) and the third groove (613) and the shortest distance (L4) between one end of the vertical direction of the vent (600) and the other end of the longitudinal direction of the first embo (621) are equal.

[0126] When the first emboss (621) is formed in such a shape, the bending of the portion adjacent to one end of the vent (600) and located between the first groove (611) and the second groove (612), and the portion located between the first groove (611) and the third groove (613), can be more effectively prevented, so that the bending of the vent (600) can be more effectively prevented when the second groove (612) and the third groove (613) break together with the first groove (611).

[0127] Next, the second embo (622) is explained.

[0128] The second emboss (622) can be formed between the first groove (611) and the other end of the vent (600) in the vertical direction.

[0129] As illustrated in FIG. 5, the second embo (622) may include a third inclined surface (622-1) which is connected to the other side of the vent (600) and located adjacent to the first groove (611), and a fourth inclined surface (622-2) which is connected to the third inclined surface (622-1) and connected to the other side of the vent (600) and located further from the first groove (611) than the third inclined surface (622-1).

[0130] At this time, the third inclined surface (622-1) and the fourth inclined surface (622-2) of the second embo (622) can be formed to effectively prevent the second embo (622) from bending, thereby effectively preventing the vent (600) from bending.

[0131] Specifically, the third slope (622-1) and the fourth slope (622-2) may be formed such that the distance between one side of the third slope (622-1) and the distance between one side of the fourth slope (622-2) and the other side are different.

[0132] That is, the second embo (622) can be formed such that the two sides are not symmetrical with respect to the groove.

[0133] In this way, when the lengths of the third inclined surface (622-1) and the fourth inclined surface (622-2) are different, the bending moment of the second embo (622) increases, just as the bending moment of the first embo (621) increases when the lengths of the aforementioned first inclined surface (621-1) and the second inclined surface (621-2) are different.

[0134] That is, when the lengths of the third inclined surface (622-1) and the fourth inclined surface (622-2) are different, the bending moment of the second embo (622) increases, and the bend (600) including the second embo (622) can be effectively prevented from bending.

[0135] Additionally, the third inclined surface (622-1) and the fourth inclined surface (622-2) of the second embo (622) may be formed to more effectively prevent the second embo (622) from bending, thereby more effectively preventing the vent (600) from bending.

[0136] Specifically, as illustrated in FIG. 7, the third inclined surface (622-1) and the fourth inclined surface (622-2) may be formed such that the angle formed by the third inclined surface (622-1) and the plane (630) parallel to the other side of the vent (600), or the angle formed by the fourth inclined surface (622-2) and the plane (630), is 90 degrees.

[0137] That is, the third inclined surface (622-1) and the fourth inclined surface (622-2) may have different lengths, and can be formed such that the angle formed by either one with the plane (630) is a right angle.

[0138] In this way, when the angle formed by the third inclined surface (622-1) or the fourth inclined surface (622-2) with the plane (630) becomes a right angle, the bending moment of the second embo (622) increases, just as the bending moment of the first embo (621) increases when the angle formed by the aforementioned first inclined surface (621-1) or the second inclined surface (621-2) with the plane (630) becomes a right angle.

[0139] That is, as the angle formed by the third inclined surface (622-1) or the fourth inclined surface (622-2) with the plane (630) approaches 90 degrees, the bending moment of the second embo (622) increases, and the bend (600) containing the second embo (622) can be prevented from bending more effectively.

[0140] Meanwhile, the second embo (622) can be formed to have various shapes formed along the length direction of the vent (600).

[0141] For example, as illustrated in FIG. 3, the second emboss (622) can be formed parallel to the first groove (611).

[0142] To explain another example, as illustrated in FIG. 9, the second emboss (621) can be formed such that the vertical distance between the second emboss (622) and the center of the vent (600) is the shortest among the vertical distances between the second emboss (622) and the first groove (611).

[0143] And, as shown in FIG. 9, the second emboss (622) can be formed such that the vertical distance between the first emboss (621) and the first groove (611) increases as it goes from the center of the vent (600) to one end in the longitudinal direction and to the other end in the longitudinal direction of the vent (600).

[0144] At this time, the second emboss (622) may be formed in a shape that can more effectively prevent the vent (600) from bending when the second groove (612) and the third groove (613) of the notch portion (610) are broken.

[0145] Specifically, referring to FIG. 9, the second embo (622) can be formed such that the shortest distance (L5) between the other end of the vertical direction of the vent (600) and the second groove (612) and the shortest distance (L6) between the other end of the vertical direction of the vent (600) and the one end of the length direction of the second embo (622) are equal.

[0146] And, the second embo (622) can be formed such that the shortest distance (L7) between the other end of the vertical direction of the vent (600) and the third groove (613) and the shortest distance (L8) between the other end of the vertical direction of the vent (600) and the other end of the longitudinal direction of the second embo (622) are equal.

[0147] When the second emboss (622) is formed in such a shape, the bending of the portion located between the first groove (611) and the second groove (612) and the portion located between the first groove (611) and the third groove (613) adjacent to the other end of the vent (600) can be more effectively prevented, so that the bending of the vent (600) can be more effectively prevented when the second groove (612) and the third groove (613) together with the first groove (611) break.

[0148] Meanwhile, the first emboss (621) and the second emboss (622) of the bending prevention part (620) may be formed symmetrically with respect to the first groove (611), and the second groove (612) and the third groove (613) of the notch part (610) may be formed symmetrically with respect to the center of the vent (600).

[0149] Hereinafter, a secondary battery according to another embodiment of the present disclosure will be described.

[0150] FIG. 10 is a perspective view of a secondary battery according to another embodiment of the present disclosure.

[0151] Referring to FIG. 10, the secondary battery (2) includes a case (1000), an electrode assembly (2000), a positive plate, a negative plate, a first cap assembly (5000), a second cap assembly (6000), and a vent (7000).

[0152] As illustrated in FIG. 10, the case (1000) may have one side and the other side open and a receiving space (15) formed inside.

[0153] And, a vent hole can be formed in the case (1000).

[0154] Such a case (1000) can form the exterior of a secondary battery (2), and depending on its shape, it can be formed in a rectangular shape, a pouch shape, etc., but the configuration of the case (1000) is not limited thereto.

[0155] Next, the electrode assembly (2000) will be described.

[0156] The electrode assembly (2000) is accommodated in a receiving space (15) and may include an anode and a cathode and a separator placed between the anode and the cathode.

[0157] Since this electrode assembly (2000) is configured identically to the electrode assembly (200) of the aforementioned secondary battery (1), except that the positive electrode blank portion or positive electrode tab is positioned so as to be exposed to one open side of the case (1000) and the negative electrode blank portion or negative electrode tab is positioned so as to be exposed to the other open side of the case (1000), a detailed description below is omitted.

[0158] Next, the positive plate will be explained.

[0159] The positive plate can be electrically connected to the positive electrode.

[0160] Specifically, the positive plate can be electrically connected by being combined with a positive non-positive portion or a positive tab exposed on one side of the case (1000). At this time, the positive plate may be made of copper or a copper alloy, but the composition of the positive plate (300) is not limited thereto.

[0161] Next, the cathode plate will be explained.

[0162] The cathode plate can be electrically connected to the cathode.

[0163] Specifically, the cathode plate may be electrically connected by being coupled to a cathode-free portion or a cathode tab exposed to the other side of the case (1000). At this time, the cathode plate may be made of aluminum or an aluminum alloy, but the composition of the cathode plate is not limited thereto.

[0164] Next, the first cap assembly (5000) will be described.

[0165] The first cap assembly (5000) is coupled to one side of the case (1000) and may include a positive terminal (5100) electrically connected to a positive electrode, and a vent hole may be formed.

[0166] The positive terminal (5100) can be formed of metal and electrically connected to the positive plate.

[0167] In this way, by electrically connecting the positive terminal (5100) to the positive plate, the positive terminal (5100) can be electrically connected to the positive.

[0168] In addition, a first injection port may be formed in the first cap assembly (5000) for injecting an electrolyte into a receiving space (15), and a stopper or the like may be attached to the first injection port to seal the receiving space (15).

[0169] Next, the second cap assembly (6000) will be described.

[0170] The second cap assembly (6000) is coupled to the other side of the case (1000) and may include a negative terminal (6100) electrically connected to the negative electrode, and a vent hole may be formed.

[0171] Additionally, a second injection port may be formed in the second cap assembly (6000) for injecting an electrolyte into the receiving space (15), and a stopper or the like may be attached to the second injection port to seal the receiving space (15).

[0172] At least one vent hole may be formed in the case (1000), the first cap assembly (5000), or the second cap assembly (6000), but it is preferable that only one vent hole be formed in the secondary battery (2).

[0173] That is, a vent hole may be formed in the case (1000), the first cap assembly (5000), or the second cap assembly (6000).

[0174] The negative terminal (6100) can be formed of metal and electrically connected to the negative plate.

[0175] In this way, by electrically connecting the negative terminal (6100) to the negative plate, the negative terminal (6100) can be electrically connected to the negative electrode.

[0176] The vent hole can be configured as a hole to connect the receiving space (15) and the outside of the receiving space (15).

[0177] A vent (7000) to be described later can be coupled to these vent holes to seal the receiving space (15).

[0178] Next, the vent (7000) is explained.

[0179] Since the configuration of the vent (7000) is the same as the configuration of the vent (600) of the secondary battery (1) described above, a detailed explanation is omitted below.

[0180] Thus, the secondary battery according to the present disclosure provides the effect that the opening for gas discharge can be formed to have the required size, as the bending is prevented by providing a bending prevention member when the vent is broken to form an opening for gas discharge.

[0181] In addition, it enables the effective discharge of gas, thereby providing the effect of effectively preventing fires.

[0182] The foregoing description of the present disclosure is for illustrative purposes only, and those skilled in the art will understand that other specific forms can be easily modified without altering the technical spirit or essential features of the present disclosure. Therefore, the embodiments described above should be understood as illustrative in all respects and not restrictive. For example, each component described as a single unit may be implemented in a distributed manner, and components described as distributed may likewise be implemented in a combined form.

[0183] The scope of the present disclosure is defined by the claims set forth below rather than by the detailed description above, and all modifications or variations derived from the meaning and scope of the claims and equivalents thereof should be interpreted as being included within the scope of the present disclosure. Explanation of the symbols

[0185] 1, 2: Secondary battery 100, 1000: Case 200, 2000: Electrode assembly 300: Positive plate 400: Cathode plate 500: Cap assembly 510: Positive terminal 520: Negative terminal 530: Inlet 600, 7000: Vent 610: Notch 611: 1st Home 612: 2nd Home 613: 3rd Home 620: Anti-bending part 621: 1st Emboss 622: 2nd Emboss

Claims

Claim 1 A secondary battery comprising: a case having one side open and a receiving space formed inside; an electrode assembly including a positive electrode and a negative electrode and a separator disposed between the positive electrode and the negative electrode, the electrode assembly being received in the receiving space; and a cap assembly coupled to the case to seal the receiving space and including a positive terminal electrically connected to the positive electrode and a negative terminal electrically connected to the negative electrode, wherein a vent hole is formed in the case or the cap assembly, and a vent that breaks when the pressure of the receiving space exceeds a preset reference pressure is coupled to the vent hole, wherein the vent comprises: a notch portion formed by grooves having a first shape on at least a portion of one side facing the receiving space or another side opposite to the one side; and a bending prevention portion formed by recessing at least a portion of the other side having a second shape. Claim 2 A secondary battery comprising: a case having one side and the other side open and having a receiving space formed inside; an electrode assembly including a positive electrode and a negative electrode and a separator disposed between the positive electrode and the negative electrode, which is received in the receiving space; a first cap assembly including a positive terminal coupled to one side of the case and electrically connected to the positive electrode; and a second cap assembly including a negative terminal coupled to the other side of the case and electrically connected to the negative electrode, wherein a vent hole is formed in the case, the first cap assembly, or the second cap assembly, and a vent that breaks when the pressure of the receiving space becomes greater than a preset reference pressure is coupled to the vent hole, wherein the vent includes a notch portion formed by grooves having a first shape on at least a part of one side facing the receiving space or another side opposite to the one side; and a bending prevention portion formed by recessing at least a part of the other side having a second shape. Claim 3 A secondary battery according to claim 1 or 2, wherein the vent is formed by extending in the longitudinal direction, and the notch portion includes a first groove formed by extending in a direction parallel to the longitudinal direction, and the first groove is formed to pass through the center of the vent, which is the midpoint between one end in the longitudinal direction and the other end in the longitudinal direction of the vent, and the midpoint between one end in the vertical direction and the other end in the vertical direction of the vent. Claim 4 In paragraph 3, the bending prevention member comprises: a first embossing formed between the first groove and one vertical end of the vent; and a second embossing formed between the first groove and the other vertical end of the vent, a secondary battery. Claim 5 A secondary battery according to claim 4, wherein the first embossing comprises: a first inclined surface having one side connected to the other side of the vent and located adjacent to the first groove; and a second inclined surface having one side connected to the other side of the first inclined surface and the other side connected to the other side of the vent and located further from the first groove than the first inclined surface, and the second embossing comprises: a third inclined surface having one side connected to the other side of the vent and located adjacent to the first groove; and a fourth inclined surface having one side connected to the third inclined surface and the other side connected to the other side of the vent and located further from the first groove than the third inclined surface. Claim 6 A secondary battery according to claim 5, wherein the distance between one side of the first inclined surface and the other side of the second inclined surface is different, and the distance between one side of the third inclined surface and the other side of the fourth inclined surface is different. Claim 7 A secondary battery according to claim 6, wherein the angle formed by the first inclined surface and a plane parallel to the other side of the vent or the angle formed by the second inclined surface and the plane is 90 degrees, and the angle formed by the third inclined surface and the plane or the angle formed by the fourth inclined surface and the plane is 90 degrees. Claim 8 A secondary battery according to claim 7, wherein the first embossing and the second embossing are formed parallel to the first groove. Claim 9 A secondary battery according to claim 8, wherein the first embossing is formed such that the vertical distance between the first embossing and the center of the vent is the shortest among the vertical distances between the first embossing and the first groove, and the second embossing is formed such that the vertical distance between the second embossing and the center of the vent is the shortest among the vertical distances between the second embossing and the first groove. Claim 10 A secondary battery according to claim 9, wherein the first embossing is formed such that the vertical distance between the first embossing and the first groove increases as it moves from the center of the vent to one end in the longitudinal direction and to the other end in the longitudinal direction of the vent, and the second embossing is formed such that the vertical distance between the second embossing and the first groove increases as it moves from the center of the vent to one end in the longitudinal direction and to the other end in the longitudinal direction of the vent. Claim 11 A secondary battery according to claim 8, wherein the notch portion further comprises: a second groove formed adjacent to the outer circumference of one longitudinal end of the vent; and a third groove formed adjacent to the outer circumference of the other longitudinal end of the vent. Claim 12 A secondary battery according to claim 11, wherein the second groove is connected to the first groove and is formed parallel to the outer circumference of one end in the longitudinal direction of the vent, and the third groove is connected to the first groove and is formed parallel to the outer circumference of the other end in the longitudinal direction of the vent. Claim 13 In Clause 12, the first emboss is formed such that the shortest distance between the vertical end of the vent and the second groove is equal to the shortest distance between the vertical end of the vent and the longitudinal end of the first emboss, and the shortest distance between the vertical end of the vent and the third groove is equal to the shortest distance between the vertical end of the vent and the longitudinal other end of the first emboss, and the second emboss is formed such that the shortest distance between the vertical other end of the vent and the second groove is equal to the shortest distance between the vertical other end of the vent and the longitudinal end of the second emboss, and the shortest distance between the vertical other end of the vent and the third groove is equal to the longitudinal other end of the third emboss. A secondary battery formed such that the shortest distance among the distances to the terminals becomes equal. Claim 14 A secondary battery according to claim 13, wherein the first embossing and the second embossing are formed symmetrically with respect to the first groove, and the second groove and the third groove are formed symmetrically with respect to the center of the vent.

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