Exhaust plate and secondary battery cell comprising same

Abstract

A secondary cell according to one embodiment of the present disclosure comprises: a case having an internal space formed therein and including an opening on at least one side; an electrode assembly which is provided in the internal space and in which negative electrodes and positive electrodes are alternately stacked with a separator interposed therebetween; the cover plate is arranged to cover the opening part; and an exhaust part which is opened when the internal space reaches a preset pressure range and comprises a base and a notch part formed on the base, and the notch part and the base satisfy the following relational expression 1: 1.2 lt; 100 * b * c / alt; 2.9 (a is the thickness of the base, b is the width of the notch part, and c is the thickness of the notch part).

Description

Technical Field

[0001] This disclosure relates to an exhaust plate and a secondary battery cell including the exhaust plate, and more specifically, to a prismatic secondary battery cell. Background Technology

[0002] Unlike primary batteries, secondary batteries are characterized by their ability to be repeatedly charged and reused, making them suitable as energy sources in various fields such as digital cameras, laptops, mobile devices, electric vehicles, and hybrid vehicles. Among secondary batteries, lithium-ion batteries are the most representative, followed by nickel-cadmium batteries and nickel-metal hydride batteries.

[0003] This type of secondary battery can be manufactured into rigid prismatic or cylindrical cells or flexible pouch-shaped cells for use, and can be used in the form of battery modules or battery packs in applications such as electric vehicles that require high output characteristics. The battery module includes one or more cell stacks in the form of multiple cells stacked together, and the battery pack includes one or more such battery modules.

[0004] On the other hand, due to the characteristics of products using rechargeable batteries, the requirements for safety are becoming increasingly stringent. In particular, in cases such as electric vehicles with multiple battery cells, there is a risk that a fire in one cell can spread to adjacent cells, triggering a chain reaction of fires and potentially leading to thermal runaway.

[0005] To prevent this thermal runaway, venting structures are used on a per-cell or per-module basis. When the internal pressure of a cell or per-module reaches a preset appropriate pressure, the venting structure breaks to release the generated gas to the outside. Summary of the Invention

[0006] (a) Technical problems to be solved

[0007] This disclosure provides a secondary battery cell including an exhaust structure capable of appropriately changing the fracture pressure.

[0008] (II) Technical Solution

[0009] A secondary battery cell according to an embodiment of this disclosure may include: a housing having an internal space and including an opening on at least one side; an electrode assembly disposed in the internal space, with negative and positive electrodes alternately stacked across a diaphragm; a cover plate configured to cover the opening; and an exhaust port that opens when the internal space reaches a preset pressure range, and includes a base and a notch formed on the base, wherein the notch and the base can satisfy the following relationship 1.

[0010] [Relation 1]

[0011] 1.2 < 100 * b * c / a < 2.9

[0012] (a: thickness of the base, b: width of the notch, c: thickness of the notch).

[0013] According to one embodiment of this disclosure, the width b of the notch and the thickness a of the base can satisfy the following relationship 2.

[0014] [Relationship 2]

[0015] 42.8 < 100 * b / a < 57.8.

[0016] According to one embodiment of this disclosure, the thickness c of the notch and the thickness a of the base can satisfy the following relationship 3.

[0017] [Relationship 3]

[0018] 14.2 < 100 * c / a < 26.4.

[0019] According to one embodiment of this disclosure, the width b and the thickness c of the notch can satisfy the following relationship 4.

[0020] [Relationship 4]

[0021] 27.2 < 100 * c / b < 55.5.

[0022] According to one embodiment of the present disclosure, the notch is formed on one side of the base facing the interior space, and may include: a first portion extending along a first direction and passing through the central portion of the base; and a second portion extending from the first portion along a direction different from the first direction.

[0023] According to one embodiment of this disclosure, the first direction may be a direction parallel to the length direction of the exhaust portion.

[0024] According to one embodiment of this disclosure, the notch may further include: a third portion extending from the second portion along the first direction to be parallel to the first portion, wherein the second portion may be perpendicular to the first portion and the third portion.

[0025] According to one embodiment of the present disclosure, the second portion may include: a second portion extending along a second direction; and a second second portion extending along a third direction intersecting the second direction.

[0026] According to one embodiment of the present disclosure, the notch may have a groove shape having a predetermined width in the thickness direction of the notch.

[0027] According to one embodiment of this disclosure, the exhaust section can be opened when the internal space reaches a pressure range of 0.7 MPa to 0.9 MPa.

[0028] According to one embodiment of this disclosure, the exhaust portion may be disposed on the housing or the cover plate.

[0029] According to one embodiment of this disclosure, the exhaust portion may be welded to the housing or the cover plate.

[0030] According to one embodiment of this disclosure, an exhaust plate may include: a base, coupled to the housing or cover plate of a secondary battery cell; and a notch formed on one side of the base, which breaks when the interior of the housing reaches a preset pressure range. The notch may include: a first portion extending along a first direction and passing through the central portion of the base; and a second portion extending from the first portion in a direction different from the first direction. The exhaust plate may satisfy the following relationship 1.

[0031] [Relation 1]

[0032] 1.2 < 100 * b * c / a < 2.9

[0033] (a: thickness of the base, b: width of the notch, c: thickness of the notch).

[0034] According to one embodiment of this disclosure, the notch may be formed on one side of the base facing the interior space.

[0035] According to one embodiment of this disclosure, the notch may further include: a third portion extending from the second portion along the first direction to be parallel to the first portion, wherein the second portion may be perpendicular to the first portion and the third portion.

[0036] (III) Beneficial Effects

[0037] According to one embodiment of the present disclosure, the secondary battery cell has the effect of causing the exhaust structure to break under desired pressure conditions. Attached Figure Description

[0038] Figure 1 This is a perspective view of a secondary battery cell according to an embodiment of the present disclosure.

[0039] Figure 2 yes Figure 1 The cross-sectional view of the secondary battery cell is shown.

[0040] Figure 3 This is a perspective view of a secondary battery cell according to another embodiment of the present disclosure.

[0041] Figure 4 yes Figure 3 The cross-sectional view of the secondary battery cell is shown.

[0042] Figure 5 This is a diagram showing an exhaust section according to an embodiment of the present disclosure.

[0043] Figure 6a It is along Figure 5 A cross-sectional view taken from the I-I' line. Figure 6b It is along Figure 5 A cross-sectional view taken from line II-II'.

[0044] Figure 7 Is with Figure 6a and Figure 6b An enlarged view of the area corresponding to the notch.

[0045] Figure 8 This is a diagram showing an exhaust section according to another embodiment of the present disclosure. Detailed Implementation

[0046] The embodiments of this disclosure will now be described in detail with reference to the accompanying drawings. However, the ideas of this disclosure are not limited to the embodiments described herein. For example, those skilled in the art who understand the ideas of this disclosure may propose other embodiments that are included within the scope of this disclosure by adding, changing, or deleting components, and these should also be included within the scope of this disclosure.

[0047] Furthermore, terms such as "first" and "second," which include ordinal numbers, used in this specification may be used to describe various components, but the components are not limited to those terms. These terms are used only to distinguish one component from another; for example, without departing from the scope of this disclosure, a first component may be named a second component, and similarly, a second component may be named a first component.

[0048] Figure 1 This is a perspective view of a secondary battery cell according to an embodiment of the present disclosure. Figure 2 yes Figure 1 The cross-sectional view of the secondary battery cell is shown below. Figure 3 This is a perspective view of a secondary battery cell according to another embodiment of the present disclosure. Figure 4 yes Figure 3 The cross-sectional view of the secondary battery cell is shown.

[0049] According to embodiments of this disclosure, the secondary battery cells 100 and 200 can be prismatic secondary battery cells packaged in a cuboid shape.

[0050] The housings 110 and 210 of the secondary battery cells 100 and 200 according to embodiments of the present disclosure can be formed in a cuboid shape. The housings 110 and 210 can be made of aluminum, and therefore, the housings 110 and 210 can be designed to have a positive polarity.

[0051] The housings 110 and 210 can form an internal space, and can accommodate the electrode assemblies 120 and 220 and the electrolyte within the internal space.

[0052] Electrode assemblies 120 and 220 may include negative electrodes 121 and 221, positive electrodes 122 and 222, and separators 123 and 223. For example, electrode assemblies 120 and 220 may be in a form where negative electrodes 121 and 221 and positive electrodes 122 and 222 are alternately stacked with separators 123 and 223 in between, or in a form where they are wound in a stacked state.

[0053] Electrode assemblies 120 and 220 may have length along the long side of the cuboid-shaped housings 110 and 210. For example, negative electrodes 121 and 221, positive electrodes 122 and 222, and diaphragms 123 and 223 may have length along the long side of the cuboid-shaped housings 110 and 210.

[0054] Negative electrodes 121 and 221 and positive electrodes 122 and 222 can be formed by coating a current collector in the form of a thin film (or foil) with a thickness of about 10 μm with an electrode active material. For example, negative electrodes 121 and 221 can be formed by coating a current collector such as copper, copper alloy, nickel, or nickel alloy with an electrode active material such as graphite or carbon. Conversely, positive electrodes 122 and 222 can be formed by coating a current collector such as aluminum or aluminum alloy with an electrode active material such as a transition metal oxide. However, the materials of the current collector and electrode active material of negative electrodes 121 and 221 and positive electrodes 122 and 222 are not limited to the materials mentioned above as examples.

[0055] On the other hand, the negative electrodes 121, 221 and the positive electrodes 122, 222 may include uncoated portions 12, 22, which are areas on the current collector where no electrode active material is coated. The uncoated portions 12, 22 may be portions extending along the length of the negative electrodes 121, 221 and the positive electrodes 122, 222. The uncoated portions 12, 22 may be electrically connected to the current collectors 150, 250 (described later), thereby becoming current flow channels between the negative electrodes 121, 221 and the positive electrodes 122, 222 and the outside.

[0056] Separators 123 and 223 can be inserted between negative electrodes 121 and 221 and positive electrodes 122 and 222 to prevent direct contact between them. Simultaneously, separators 123 and 223 can include micro-sized pores on their surface to allow the movement of lithium ions in the electrolyte. For example, separators 123 and 223 can be made of polyethylene (PE) or polypropylene (PP). However, the materials of separators 123 and 223 are not limited to these.

[0057] The internal spaces formed by the housings 110 and 210 can accommodate the electrode assemblies 120 and 220 and the electrolyte. For example, the electrolyte may contain lithium salts such as LiPF6 and LiBF4 in organic solvents such as ethylene carbonate (EC), propylene carbonate (PC), diethyl carbonate (DEC), ethyl methyl carbonate (EMC), and dimethyl carbonate (DMC). Alternatively, the electrolyte may be liquid, solid, or gel-like.

[0058] According to embodiments of this disclosure, housings 110 and 210 may include an opening on at least one side. Covers 130 and 230 may be provided at the openings, and the covers 130 and 230 may be configured to cover the openings to seal the internal space.

[0059] Reference Figure 1 and Figure 2 The housing 110 may include an opening on one side (one-way type). For example, based on the figure, the housing 110 may include an opening on one side in the z-direction. In this embodiment, the opening may have a length along the long side of the housing 110, and the cover plate 130 may be configured to cover the opening.

[0060] On the other hand, refer to Figure 3 and Figure 4 The housing 210 may include openings on both sides (bidirectional type). For example, based on the figure, the housing 210 may include openings on both sides in the x-direction. In this embodiment, the openings may have a length along the height direction of the housing 210, and the cover plate 230 may be configured to cover the openings.

[0061] Refer again Figure 1 and Figure 2 The cover plate 130 can be attached to the housing 110 while being configured to cover the opening. The cover plate 130 can be made of aluminum and can be welded to the housing 110 along the periphery of the opening.

[0062] The cover plate 130 may include electrode terminals (140: 141, 142). For example, the cover plate 130 may include a negative terminal 141 and a positive terminal 142. The negative terminal 141 may be electrically connected to the negative terminal 121 of the electrode assembly 120 to have a negative polarity, and the positive terminal 142 may be electrically connected to the positive terminal 122 of the electrode assembly 120 to have a positive polarity.

[0063] The negative terminal 141 and the positive terminal 142 can be arranged in the form of a plate and can be spaced apart along the length of one side of the cover plate 130. One side of the cover plate 130 can be the side opposite to the side facing the interior space. However, the negative terminal 141 and the positive terminal 142 are not limited to the above embodiment, as long as they are in a form that can be electrically connected to the outside.

[0064] Negative terminal 141 and positive terminal 142 can be electrically connected to current collectors (150: 151, 152). Current collector 150 can be connected to the uncoated portions (12: 12a, 12b) of electrode assembly 120 to have negative or positive polarity. Negative terminal 141 can be electrically connected to the negative current collector 151 with the uncoated portion 12a of negative terminal 121 soldered thereto, and positive terminal 142 can be electrically connected to the positive current collector 152 with the uncoated portion 12b of positive terminal 122 soldered thereto.

[0065] Reference Figure 1 and Figure 2 The negative terminal 141 and the positive terminal 142 can be electrically connected to the current collector 150 via connecting pins (145: 145a, 145b), respectively. For example, through holes can be formed in the cover plate 130 and the electrode terminal 140, and the connecting pin 145 can be configured to pass through the through holes. One side of the connecting pin 145 can be soldered to the current collector 150, and the other side can be soldered to the electrode terminal 140.

[0066] According to embodiments of this disclosure, since the housing 110 and cover plate 130 of the secondary battery cell 100 have positive polarity, an insulating component can be further provided between the component with negative polarity and the cover plate 130.

[0067] For example, first to third insulating components 135, 136, and 137 can be provided on one and the other side of the cover plate 130 and within the through hole of the cover plate 130. For example, the first insulating component 135 provided on one side of the cover plate 130 can be provided between the cover plate 130 and the negative terminal 141 to electrically insulate the cover plate 130 from the negative terminal 141. The second insulating component 136 provided on the other side of the cover plate 130 can be provided between the cover plate 130 and the negative current collector plate 151. In addition, the third insulating component 137 provided within the through hole of the cover plate 130 can electrically insulate the cover plate 130 from the connecting pin 145a provided within the through hole.

[0068] On the other hand, as described above, since the connecting pin 145 is provided in the through holes of the cover plate 130 and the electrode terminal 140, with one end welded to the current collector plate 150 and the electrode terminal 140 respectively, the components provided between the electrode terminal 140 and the current collector plate 150 can all have through holes. For example, the cover plate 130 and the first to third insulating members 135, 136, and 137 provided between the negative terminal 141 and the negative current collector plate 151 can all have through holes, and the negative connecting pin 145a can be provided to pass through the through hole. In particular, the third insulating member 137 can be provided in the through hole of the cover plate 130, and the negative connecting pin 145a can be provided in the through hole of the third insulating member 137. Therefore, the negative connecting pin 145a and the cover plate 130 can be electrically insulated by the third insulating member 137.

[0069] Reference Figure 3 and Figure 4 The housing 210 may include openings on both sides along its length, and cover plates (230: 230a, 230b) may be configured to cover each opening. The cover plates 230 may be made of aluminum and may be welded to the housing 210 along the periphery of the openings.

[0070] The cover plate 230 may include electrode terminals (240: 241, 242). For example, the cover plate 230 may include a negative terminal 241 and a positive terminal 242. Hereinafter, a first cover plate 230a may refer to a cover plate including the negative terminal 241, and a second cover plate 230b may refer to a cover plate including the positive terminal 242.

[0071] As described above, the negative terminal 241 can be electrically connected to the negative terminal 221 of the electrode assembly 220 to have a negative polarity, and the positive terminal 242 can be electrically connected to the positive terminal 222 of the electrode assembly 220 to have a positive polarity.

[0072] The negative terminal 241 and the positive terminal 242 can be provided in the form of a plate and can be provided on one side of the cover plate 230. One side of the cover plate 230 can be the side opposite to the side facing the interior space. However, the negative terminal 241 and the positive terminal 242 are not limited to the above embodiment, as long as they are in a form that can be electrically connected to the outside.

[0073] Negative terminal 241 and positive terminal 242 can be electrically connected to current collector plates (250: 251, 252). Current collector plate 250 can be connected to the uncoated portions (22: 22a, 22b) of electrode assembly 220 to have negative or positive polarity. Negative terminal 241 can be electrically connected to negative current collector plate 251 with uncoated portion 22a having negative terminal 221 soldered to it, and positive terminal 242 can be electrically connected to positive current collector plate 252 with uncoated portion 22b having positive terminal 222 soldered to it.

[0074] Reference Figure 3 and Figure 4 The negative terminal 241 and the positive terminal 242 can be electrically connected to the current collector 250 via connecting pins (245: 245a, 245b), respectively. For example, through holes can be formed in the cover plate 230 and the electrode terminal 240, and the connecting pin 245 can be configured to pass through the through holes. One side of the connecting pin 245 can be soldered to the current collector 250, and the other side can be soldered to the electrode terminal 240.

[0075] According to embodiments of this disclosure, since the housing 210 and cover plate 230 of the secondary battery cell 200 have positive polarity, an insulating component can be further provided between the component with negative polarity and the cover plate 230.

[0076] For example, an insulating component can be further provided between the component with negative polarity and the first cover plate 231. First to third insulating components 235, 236, and 237 can be provided on one and the other side of the first cover plate 231 and in the through-hole of the first cover plate 231. For example, the first insulating component 235 provided on one side of the first cover plate 231 can be provided between the first cover plate 231 and the negative terminal 241 to electrically insulate the first cover plate 231 from the negative terminal 241. The second insulating component 236 provided on the other side of the first cover plate 231 can be provided between the first cover plate 231 and the negative current collector 251. Furthermore, the third insulating component 237 provided in the through-hole of the first cover plate 231 can electrically insulate the first cover plate 231 from the connecting pin 245a provided in the through-hole.

[0077] On the other hand, as described above, since the connecting pin 245 is disposed in the through holes of the cover plate 230 and the electrode terminal 240, with one end welded to the current collector plate 250 and the electrode terminal 240 respectively, the components disposed between the electrode terminal 240 and the current collector plate 250 can all have through holes. For example, the first cover plate 231 and the first to third insulating components 235, 236, and 237 disposed between the negative terminal 241 and the negative current collector plate 251 can all have through holes, and the negative connecting pin 245a can be disposed through the through hole. In particular, the third insulating component 237 can be disposed in the through hole of the first cover plate 231, and the negative connecting pin 245a can be disposed in the through hole of the third insulating component 237. Therefore, the negative connecting pin 245a and the first cover plate 231 can be electrically insulated by the third insulating component 237.

[0078] According to embodiments of this disclosure, secondary battery cells 100 and 200 may include venting sections (or venting plates) 170 and 270. Hereinafter, reference will be made to... Figures 5 to 7 The exhaust sections 170 and 270 according to embodiments of the present disclosure will be described.

[0079] Figure 5 This is a diagram illustrating an exhaust section according to an embodiment of the present disclosure. Figure 6a It is along Figure 5 A cross-sectional view taken from the I-I' line. Figure 6b It is along Figure 5 A cross-sectional view taken from line II-II'. Figure 7 Is with Figure 6a and Figure 6b Enlarged view of the area corresponding to the notch. Figure 8 This is a diagram showing an exhaust section according to another embodiment of the present disclosure.

[0080] The exhaust vents 170 and 270 can be structures used to prevent the secondary battery cells 100 and 200 from exploding. For example, due to repeated charging and discharging of the secondary battery cells 100 and 200, gas may be generated inside the housings 110 and 210, and when the generated gas causes the internal pressure of the housings 110 and 210 to reach a predetermined level, the gas inside the housings 110 and 210 can be discharged to the outside through the exhaust vents 170 and 270.

[0081] As an example, such as Figure 1 and Figure 3 As shown, exhaust sections 170 and 270 can be installed on cover plates 130 and 230.

[0082] The exhaust portions 170 and 270 may include bases 171 and 271 arranged in the form of plates. The bases 171 and 271 may be made of aluminum and may be attached to the cover plates 130 and 230. For example, the cover plates 130 and 230 may include openings that engage with the bases 171 and 271, and the bases 171 and 271 may be welded to the cover plates 130 and 230 along the periphery of the openings.

[0083] On the other hand, as another embodiment, exhaust portions 170 and 270 can also be provided on housings 110 and 210. In this case, housings 110 and 210 may include openings that engage with bases 171 and 271 of exhaust portions 170 and 270, and bases 171 and 271 may be welded to housings 110 and 210 along the periphery of the openings. In this case, exhaust portions 170 and 270 may be provided on a surface different from the surface on which the cover plates 130 and 230 of housings 110 and 210 are provided.

[0084] Notches 172 and 272 may be formed in the bases 171 and 271. Compared to other parts of the bases 171 and 271, the thickness of the notches 172 and 272 may be relatively thin, for example, they may be grooves with a predetermined width and depth (or thickness). The notches 172 and 272 may be formed on one side of the bases 171 and 271 facing the interior space. That is, the notches 172 and 272 may be provided in the form of continuous grooves on one side of the bases 171 and 271. In addition, the notches 172 and 272 may have a groove shape with a predetermined width in the thickness direction of the notches 172 and 272.

[0085] The notches 172 and 272 can have any shape. For example, the notches 172 and 272 can be symmetrical. In addition, the notches 172 and 272 can include first portions 172a and 272a and second portions 172b and 272b extending from the first portions 172a and 272a.

[0086] The first portions 172a and 272a may be portions extending along a first direction and passing through the central portion of the bases 171 and 271. For example, the first direction may be a direction parallel to the length direction of the bases 171 and 271. However, the first direction may also be other directions. On the other hand, the notches 172 and 272 may include multiple first portions 172a and 272a. In this case, the first direction may be applied differently to each first portion 172a and 272a.

[0087] The second portions 172b and 272b may be portions extending from the first portions 172a and 272a in a direction different from the first direction. The second portions 172b and 272b may extend from one end and the other end of the first portions 172a and 272a, respectively. Furthermore, one end and the other end of the first portions 172a and 272a may each include a plurality of second portions 172b and 272b. As one embodiment, a plurality of second portions 172b and 272b may extend from one end and the other end of the first portions 172a and 272a, and the second portions 172b and 272b may extend in directions different from each other. For example, the second portions 172b and 272b may include a second portion extending in a second direction and a second portion extending in a third direction.

[0088] Figure 8 An exhaust section 370 according to another embodiment of the present disclosure is shown. It is identical to the notches 172 and 272 of the exhaust sections 170 and 270 according to the embodiments described above. Figure 8The notch 372 of the exhaust section 370 shown may include a first portion 372a extending along a first direction and passing through the central portion of the base 371, and a second portion 372b extending from the first portion 372a in a direction different from the first direction. Additionally, in Figure 8 In the middle, the notch 372 may further include a third portion 372c extending from the second portion 372b along a first direction and parallel to the first portion 372a. Additionally, the second portion 372b may be perpendicular to the first portion 372a and the third portion 372c.

[0089] According to embodiments of this disclosure, the venting sections 170 and 270 can be designed to break under a pressure of 0.7 MPa or higher and 0.9 MPa or lower within their internal spaces. Specifically, when the internal spaces of the secondary cells 100 and 200 reach the above pressure range, the notches 172 and 272 of the venting sections 170 and 270 break, allowing the gas generated within the internal spaces to be discharged to the outside. The venting sections 170 and 270 according to embodiments of this disclosure can be designed to break under the pressure optimal for improving battery life and ensuring safety.

[0090] On the other hand, the exhaust sections 170 and 270 may deform due to the heat generated when the bases 171 and 271 are welded to the cover plates 130 and 230 or the housings 110 and 210, which may cause the exhaust sections 170 and 270 to break before reaching the preset pressure condition. In addition, without changing the shape of the notches 172 and 272, the exhaust sections 170 and 270 have limitations in adjusting the range of fracture pressure.

[0091] According to embodiments of the present disclosure, the exhaust portions 170 and 270 can be designed such that the bases 171 and 271 and the notches 172 and 272 satisfy at least one of the following relationships, so that even if the above-mentioned problems exist, the exhaust portions 170 and 270 can break under a preset pressure condition.

[0092] Reference Figure 7 When the thickness of the bases 171 and 271 is a, the width of the notches 172 and 272 is b, and the thickness of the notches 172 and 272 is c, the bases 171 and 271 and the notches 172 and 272 can satisfy the following relationship 1.

[0093] [Relation 1]

[0094] 1.2 < 100 * b * c / a < 2.9

[0095] According to embodiments of this disclosure, the time point at which the exhaust portions 170 and 270 break is related to the area of ​​the notches 172 and 272 (i.e., the width b and thickness c of the notches 172 and 272) and the thickness a of the bases 171 and 271, and when the exhaust portions 170 and 270 are designed to satisfy the above relationship 1, they can break under the pressure range described above.

[0096] Furthermore, based on the above relationships, the bases 171 and 271 and the notches 172 and 272 of the exhaust portions 170 and 270 can further satisfy the following relationships 2 to 4.

[0097] [Relationship 2] 42.8 < 100 * b / a < 57.8

[0098] [Relationship 3] 14.2 < 100 * c / a < 26.4

[0099] [Relationship 4] 27.2 < 100 * c / b < 55.5

[0100] According to embodiments of this disclosure, the thickness a of the bases 171 and 271, and the width b and thickness c of the notches 172 and 272, can be constant (with an error range of 0.01 mm). In particular, the bases 171 and 271 can have a thickness a in the range of 0.2 mm (±0.01).

[0101] As described above, the venting portions 170 and 270 of the secondary cells 100 and 200 according to embodiments of the present disclosure can be broken with high reliability under desired pressure conditions by controlling the area and / or thickness of the notches 172 and 272.

[0102] While the structure and features of this disclosure have been described above based on embodiments according to this disclosure, this disclosure is not limited thereto. Furthermore, it will be apparent to those skilled in the art that various changes or modifications can be made to this disclosure within its spirit and scope, and therefore such changes or modifications should fall within the scope of the claims of this disclosure.

Claims

1. A secondary battery cell, comprising: The shell has an internal space and includes an opening on at least one side; An electrode assembly is disposed in the internal space, with negative and positive electrodes stacked alternately across a diaphragm; A cover plate is configured to cover the opening; as well as The exhaust section opens when the internal space reaches a preset pressure range, and includes a base and a notch formed on the base. The notch and the base satisfy the following relationship 1. [Relationship 1] 1.2 < 100 * b * c / a < 2.9, Where a is the thickness of the base, b is the width of the notch, and c is the thickness of the notch.

2. The secondary battery cell according to claim 1, wherein, The width (b) of the notch and the thickness (a) of the base satisfy the following relationship 2. [Relation 2] 42.8 < 100 * b / a < 57.

8.

3. The secondary battery cell according to claim 1, wherein, The thickness (c) of the notch and the thickness (a) of the base satisfy the following relationship 3. [Relationship 3] 14.2 < 100 * c / a < 26.

4.

4. The secondary battery cell according to claim 1, wherein, The width (b) and thickness (c) of the notch satisfy the following relationship 4. [Relation 4] 27.2 < 100 * c / b < 55.

5.

5. The secondary battery cell according to claim 1, wherein, The notch is formed on one side of the base facing the interior space and includes: The first part extends along a first direction and passes through the central portion of the base; and The second part extends from the first part in a direction different from the first direction.

6. The secondary battery cell according to claim 5, wherein, The first direction is a direction parallel to the length direction of the exhaust section.

7. The secondary battery cell according to claim 6, wherein, The notch further includes: The third part extends from the second part along the first direction, so as to be parallel to the first part. The second part is perpendicular to the first part and the third part.

8. The secondary battery cell according to claim 5, wherein, The second part includes: The second part extends along the second direction; and The second part extends along a third direction that intersects the second direction.

9. The secondary battery cell according to claim 1, wherein, The notch has a groove shape with a predetermined width in the thickness direction of the notch.

10. The secondary battery cell according to claim 1, wherein, The exhaust section opens when the internal space reaches a pressure range of 0.7 MPa to 0.9 MPa.

11. The secondary battery cell according to claim 1, wherein, The exhaust section is disposed on the housing or the cover plate.

12. The secondary battery cell according to claim 1, wherein, The exhaust section is welded to the housing or the cover plate.

13. An exhaust plate, comprising: The base is attached to the casing or cover plate of the secondary battery cell; as well as A notch is formed on one side of the base, which breaks when the internal pressure of the housing reaches a preset range. The notch includes: The first part extends along a first direction and passes through the central portion of the base; and The second part extends from the first part in a direction different from the first direction. The exhaust plate satisfies the following relationship 1. [Relationship 1] 1.2 < 100 * b * c / a < 2.9, Where a is the thickness of the base, b is the width of the notch, and c is the thickness of the notch.

14. The exhaust plate according to claim 13, wherein, The notch is formed on one side of the base facing the interior space.

15. The exhaust plate according to claim 13, wherein, The notch further includes: The third part extends from the second part along the first direction, so as to be parallel to the first part. The second part is perpendicular to the first part and the third part.

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