Secondary battery and method of manufacturing the same

Abstract

The present disclosure relates to a secondary battery and a method of manufacturing the same. A secondary battery includes: a case in which an electrode assembly is accommodated; a cap plate coupled to the housing; and a degassing device on one of the housing and the cover plate, the degassing device including: an exhaust plate exposed to an outside of the housing; a coupling portion around the exhaust plate and coupled to one of the housing and the cover plate; a notch portion in the exhaust plate, the notch portion including a notch and defining an outer cutting line of an opening portion of the exhaust plate, and the opening portion partially opening when an event occurs; and a non-notched portion in the exhaust plate, the non-notched portion not including a notch and connecting the opening portion when partially opened to the exhaust plate.

Description

Technical Field

[0001] This disclosure relates to a degassing device installed in a secondary battery, a secondary battery including the degassing device, and a method for manufacturing the secondary battery. Background Technology

[0002] Unlike primary batteries, which cannot be recharged, secondary batteries are batteries that can be charged and discharged. A secondary battery mainly consists of an electrode assembly, a housing (or canister) that contains the electrode assembly, and a cover assembly. The electrode assembly includes a positive electrode plate, a separator, and a negative electrode plate. The cover assembly includes external terminals that allow the electrode assembly to be connected to an external power source or load.

[0003] One of the main causes of fires and explosions in secondary batteries is the presence of flammable gases, and the risk of thermal runaway increases when multiple batteries are tightly packed together. Secondary batteries include venting devices, or degassing mechanisms, for releasing gases generated inside the casing. In these degassing mechanisms, notches can rupture due to the pressure of gases generated by overcharging or abnormal operation of the battery, allowing the gases to escape to the outside and thus preventing secondary battery explosions.

[0004] The degassing device can be installed in the cover assembly or the housing. In cylindrical batteries, the degassing device can be located as part of the cover assembly between the top cover and the sub-plate, and in prismatic batteries, the degassing device can be integrated into a hole formed in the cover plate, or in some cases, into a hole formed in the battery housing.

[0005] The information disclosed in this background section is intended to enhance the understanding of the background art of this disclosure, and therefore may contain information that does not constitute related (or prior art). Summary of the Invention

[0006] According to one aspect of this disclosure, a secondary battery is provided, comprising: a housing in which an electrode assembly is housed; a cover plate coupled to the housing; and a degassing device mounted on one of the housing and the cover plate. The degassing device may include: a vent plate exposed to the outside of the housing; a coupling portion coupled to one of the housing and the cover plate; a notch portion in the vent plate, the notch portion including a notch and defining an outer cutting line of an opening portion of the vent plate, the opening portion being partially openable in the event of an event; and a non-notch portion in the vent plate, the non-notch portion not including a notch and connecting the opening portion to the vent plate when the opening portion is partially open.

[0007] According to another aspect of this disclosure, a method for manufacturing a secondary battery is provided, the method comprising: forming a gas vent hole in one of a housing and a cover plate; manufacturing a degassing device configured to vent gas inside the housing in the event of an event; and incorporating the degassing device into the gas vent hole, wherein manufacturing the degassing device comprises: forming a vent plate such that the vent plate is exposed to the outside of the housing through the gas vent hole, and forming an engagement portion around the vent plate; providing a notch portion defining an outer cut line of an opening portion, the vent plate being partially opened through the opening portion in the event of an event; and providing a non-notch portion such that the opening portion, which is cut and opened along the outer cut line in the event of an event, does not separate from the vent plate. Attached Figure Description

[0008] Features will become apparent to those skilled in the art from the detailed description of exemplary embodiments with reference to the accompanying drawings, wherein:

[0009] Figure 1 This is a cross-sectional view of a cylindrical secondary battery according to some embodiments of the present disclosure;

[0010] Figure 2 This is a top perspective view of a prism-shaped secondary battery according to some embodiments of the present disclosure;

[0011] Figure 3 It is along Figure 2 A cross-sectional view of line I-I' in the diagram;

[0012] Figure 4 This is an exploded perspective view of a prismatic secondary battery according to another embodiment;

[0013] Figure 5 This is a schematic diagram of a degassing apparatus according to some embodiments of the present disclosure.

[0014] Figure 6 This is a plan view of a degassing apparatus according to some embodiments of the present disclosure;

[0015] Figure 7 It is along Figure 6 A cross-sectional view of line Y-Y' in the diagram;

[0016] Figure 8 This illustrates the state where the notch is cut by the gas pressure inside the battery and the opening is open.

[0017] Figures 9A to 9C Examples of various shapes and areas of the opening;

[0018] Figure 10A and Figure 10B An example is shown where the notched portion is formed asymmetrically relative to the non-notched portion to change the degassing direction;

[0019] Figure 11A and Figure 11B An example showing a notch formed solely by straight lines;

[0020] Figures 12A to 12D Examples of degassing devices with circular outlines are shown;

[0021] Figure 13 and Figure 14 Example Figure 7 Modified implementation examples;

[0022] Figure 15 This is a view of a secondary battery module including a secondary battery manufactured according to embodiments of the present disclosure;

[0023] Figure 16 It includes Figure 15 Example diagram of the secondary battery pack in the secondary battery module; and

[0024] Figure 17 Examples have Figure 16 Vehicles equipped with secondary battery packs. Detailed Implementation

[0025] Exemplary embodiments will now be described more fully with reference to the accompanying drawings; however, they may be implemented in different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey exemplary implementation to those skilled in the art. Furthermore, the terms or words used in this specification and claims should not be interpreted narrowly according to their general or dictionary meaning, but should be interpreted as having meanings and concepts consistent with the technical spirit of this disclosure.

[0026] In the accompanying drawings, the dimensions of layers and regions may be enlarged for clarity of illustration. It will also be understood that when a layer or element is referred to as being "on" another layer or substrate, it may be directly on that layer or substrate, or there may be intermediate layers. Furthermore, it will be understood that when a layer is referred to as being "between" two layers, it may be the only layer between the two layers, or there may be one or more intermediate layers. The same reference numerals always indicate the same elements.

[0027] The embodiments described in this specification and the configurations shown in the accompanying drawings are only some of the embodiments of this disclosure and do not represent all aspects of this disclosure, features, and embodiments. Therefore, it should be understood that various equivalents and modifications that can replace or modify one or more embodiments or features described herein may exist at the time of filing this application.

[0028] It will be understood that when a component or layer is described as "linked to," "connected to," or "attached to" another component or layer, it can be directly linked to, connected to, or attached to the other component or layer, or there may be one or more intermediate components or layers. When a component or layer is described as "directly linked to," "directly connected to," or "directly attached to" another component or layer, there are no intermediate components or layers. For example, if a first component is described as "linked" or "connected to" a second component, the first component can be directly linked to or connected to the second component, or the first component can be indirectly linked to or connected to the second component via one or more intermediate components.

[0029] The same reference numerals indicate the same elements. As used herein, the term “and / or” includes any and all combinations of one or more of the associated listed items. Furthermore, the use of “may” in describing embodiments of this disclosure refers to “one or more embodiments of this disclosure.” Expressions such as “at least one of…” and “any one of…” preceding / following the list of elements modify the entire list of elements, not individual elements in the list. When phrases such as “at least one of A, B, and C,” “at least one of A, B, or C,” “at least one selected from the group of A, B, and C,” or “at least one selected from A, B, and C” are used to specify a list of elements A, B, and C, the phrase may refer to any and all suitable combinations or subsets of A, B, and C, such as A, B, C, A and B, A and C, B and C, or A and B and C. As used herein, the term “use” may be considered synonymous with the term “utilize.” As used herein, the terms “generally,” “approximately,” and similar terms are used as approximate terms rather than terms of degree and are intended to account for inherent variations in measurements or calculations that are perceptible to those skilled in the art.

[0030] It will be understood that while the terms first, second, third, etc., may be used to describe various elements, components, regions, layers, and / or segments, these elements, components, regions, layers, and / or segments should not be limited by these terms. These terms are used to distinguish one element, component, region, layer, or segment from another element, component, region, layer, or segment. Therefore, without departing from the teachings of the exemplary embodiments, the first element, component, region, layer, or segment discussed below may be referred to as the second element, component, region, layer, or segment.

[0031] For ease of description, this document uses spatial relative terms such as “below,” “under,” “down,” “above,” and “up” to describe the relationship between one element or feature and another element or feature as shown in the figures. It should be understood that spatial relative terms are intended to encompass different orientations of the device in use or operation, in addition to the orientation depicted in the figures. For example, if the device in the figures is flipped, an element described as “below” or “under” other elements or features can be oriented as “above” or “upon” other elements or features. Therefore, the term “below” can encompass both above and below orientations. The device can be positioned in other ways (rotated 90 degrees or in other orientations), and the spatial relative descriptors used herein should be interpreted accordingly.

[0032] The terminology used herein is for the purpose of describing embodiments of this disclosure and is not intended to be limiting of this disclosure. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. It should be further understood that when used in this specification, the terms “comprising” and / or “including” specify the presence of the stated features, integers, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

[0033] Furthermore, any numerical ranges disclosed and / or enumerated herein are intended to include all subranges with the same numerical precision contained within the enumerated ranges. For example, the range “1.0 to 10.0” is intended to include all subranges between the enumerated minimum value of 1.0 and the enumerated maximum value of 10.0 (and including both the enumerated minimum value of 1.0 and the enumerated maximum value of 10.0), i.e., a minimum value equal to or greater than 1.0 and a maximum value equal to or less than 10.0, such as 2.4 to 7.6. Any maximum numerical limit enumerated herein is intended to include all lower numerical limits contained therein, and any minimum numerical limit enumerated in this specification is intended to include all higher numerical limits contained therein. Therefore, the applicant reserves the right to amend this specification, including the claims, to expressly enumerate any subranges contained within the scope expressly enumerated herein. All such ranges are intended to be inherently described in this specification such that any modifications made to expressly enumerate any such subranges will comply with patent regulations.

[0034] Referring to two compared elements, features, etc., as “identical” may mean that they are “substantially identical.” Therefore, the phrase “substantially identical” can include cases with deviations considered low in the art, such as 5% or less. Furthermore, if a parameter is described as consistent within a given region, this may mean that it is consistent in terms of its mean.

[0035] Throughout this specification, unless otherwise stated, each element may be singular or plural.

[0036] Placing any element "above (or below)" or "above (or below)" another element may mean that the arbitrary element can contact the upper (or lower) surface of the element, and other elements may also be located between the element and any element placed on (or below) the element.

[0037] Throughout this specification, unless otherwise stated, if "A and / or B" is stated, it means A, B, or A and B. In other words, "and / or" includes any or all combinations of the listed items. Unless otherwise indicated, when "C to D" is stated, it means C or more and D or fewer.

[0038] The terminology used herein is for the purpose of describing embodiments of this disclosure and is not intended to limit this disclosure.

[0039] Figure 1 Examples of cylindrical secondary batteries according to some embodiments of the present disclosure.

[0040] refer to Figure 1 The secondary battery may include an electrode assembly 30, a housing 140 containing the electrode assembly 30 and an electrolyte, a cover assembly 50 connected to an opening in the housing 140 to seal the housing 140, and an insulating plate 37 located inside the housing 140 between the electrode assembly 30 and the cover assembly 50.

[0041] The electrode assembly 30 may include a diaphragm 30b between the first electrode 30c and the second electrode 30a, and may be wound into an electrode core shape.

[0042] The first electrode 30c may include a first substrate and a first active material layer on the first substrate. A first lead tab 35 may extend outward from a first uncoated portion of the first active material layer that is not positioned on the first substrate, and the first lead tab 35 may be electrically connected to the cover assembly 50.

[0043] The second electrode 30a may include a second substrate and a second active material layer on the second substrate. A second lead tab 34 may extend outward from a second uncoated portion of the second active material layer not positioned on the second substrate, and the second lead tab 34 may be electrically connected to the housing 140. The first lead tab 35 and the second lead tab 34 may extend in opposite directions.

[0044] The first electrode 30c can be used as a positive electrode. In this embodiment, for example, the first substrate can be made of aluminum foil, and the first active material layer can include, for example, a transition metal oxide. The second electrode 30a can be used as a negative electrode. In this embodiment, for example, the second substrate can be made of copper foil or nickel foil, and the second active material layer can include, for example, graphite.

[0045] The separator 30b prevents short circuits between the first and second electrodes while allowing lithium ions to move between them. For example, the separator 30b can be made of polyethylene membrane, polypropylene membrane, polyethylene-polypropylene membrane, etc.

[0046] The housing 140 can accommodate the electrode assembly 30 and, together with the cover assembly 50, form the appearance of a secondary battery. The housing 140 can have a generally cylindrical body portion 140b and a bottom portion 140a connected to one side (e.g., one end) of the body portion 140b. An inwardly deformed rolled edge portion 31 (e.g., a rolled edge) can be formed in the body portion 140b, and an inwardly bent crimp portion 33 (e.g., a crimping member) can be formed at the open end of the body portion 140a.

[0047] The rolled edge 31 reduces or prevents movement of the electrode assembly 30 within the housing 140 and facilitates placement of the gasket 32 ​​and the cover assembly 50. The crimping portion 33 securely holds the cover assembly 50 in place by pressing the edge of the housing 140 against the gasket 32. For example, the housing 140 may be formed of nickel-plated steel.

[0048] The cover assembly 50 can be secured to the interior of the crimp portion 33 via the gasket 32 ​​to seal the housing 140. The cover assembly 50 may include an upper cover 51, a safety vent 52, a lower cover 53, an insulating member, and a sub-plate 54, but may be modified in various ways.

[0049] The top cover 51 may be located at the uppermost part of the cover assembly 50. The top cover 51 may include an upwardly protruding terminal portion that is connected to an external circuit, and an outlet for venting gas may be arranged around the terminal portion.

[0050] A safety vent 52 may be located below the top cover 51. The safety vent 52 may include a downwardly projecting protrusion that connects to the sub-plate 54, and at least one recess may be formed in the safety vent 52 around the protrusion. When gas is generated due to overcharging or abnormal operation of the secondary battery, the protrusion deforms upward under pressure and separates from the sub-plate 54, while the safety vent 52 is cut (e.g., burst or tear) along the recess. The cut safety vent 52 prevents the secondary battery from exploding by allowing gas to escape to the outside.

[0051] The lower cover 53 may be located below the safety vent 52. The lower cover 53 may have a first opening for exposing the protrusion of the safety vent 52 and a second opening for gas venting. An insulating member may be located between the safety vent 52 and the lower cover 53 to insulate the safety vent 52 from the lower cover 53.

[0052] Subplate 54 can be located below lower cover 53. Subplate 54 can be fixed to the lower surface of lower cover 53 to block the first opening of lower cover 53, and the protrusion of safety vent 52 can be fixed to subplate 54. First lead connector 35 extending from electrode assembly 30 can be fixed to subplate 54. Accordingly, upper cover 51, safety vent 52, lower cover 53 and subplate 54 can be electrically connected to the first electrode 30c of electrode assembly 30.

[0053] The insulating plate 37 can be positioned below the rolled edge 13 to contact the electrode assembly 30. The insulating plate 37 may have a tab opening through which a first lead tab 35 is led out. The cover assembly 50, electrically connected to the first electrode 30c via the first lead tab 35, can face the electrode assembly 30 with the insulating plate 37 between it and the electrode assembly 30, and can be kept insulated (e.g., electrically insulated) from the electrode assembly 30 by the insulating plate 37. Additionally, another insulating plate 36 may be included for insulation between the electrode assembly 30 and the bottom portion 140a of the housing 140.

[0054] Figure 2 This is a top perspective view of a prismatic secondary battery according to some embodiments of the present disclosure.

[0055] refer to Figure 2 The housing 59 defines the overall appearance of the prismatic secondary battery and can be made of a conductive metal such as aluminum, aluminum alloy, or nickel-plated steel. Furthermore, the housing 59 provides space for housing the electrode assembly therein.

[0056] The cover assembly 60 may include a cover plate 61 that covers the opening of the housing 59. In some examples, the housing 59 and the cover plate 61 may be made of a conductive material. Here, the first terminal 62 and the second terminal 63 may be electrically connected to corresponding positive and negative electrodes (or negative and positive electrodes) inside the housing 59 and may be mounted to protrude outward through the cover plate 61.

[0057] The cover plate 61 may be equipped with an electrolyte inlet 64 formed to accommodate a sealing plug (or sealing pin), and a venting device (e.g., a degassing device 66) may be formed in the gas vent 65. The venting device can release gases generated inside the secondary battery.

[0058] Figure 3 It is according to some embodiments of this disclosure along Figure 2 The cross-sectional view taken from line I-I'. (Reference) Figure 3 The internal structure of the prismatic secondary battery and its connection structure with the cover assembly 60 will be further described.

[0059] refer to Figure 3The prismatic secondary battery may include an electrode assembly 40, a first current collector 41, a first terminal 62, a second current collector 42, a second terminal 63, a housing 59, and a cover assembly 60.

[0060] Electrode assembly 40 can be formed by winding or stacking a first electrode plate, a diaphragm, and a second electrode plate. For example, when electrode assembly 40 is a wound stack, the winding axis can be parallel to the longitudinal direction of housing 59. In another example, electrode assembly 40 can be a stack type instead of a wound type. Furthermore, electrode assembly 40 can be a Z-stack electrode assembly, in which positive and negative electrode plates are inserted into both sides of the diaphragm, and then the Z-stack electrode assembly is bent into a Z-stack. Additionally, one or more electrode assemblies can be stacked such that the long sides of the electrode assemblies are adjacent to each other and housed within the housing. The first electrode plate of the electrode assembly can be used as a negative electrode, and the second electrode plate can be used as a positive electrode, or vice versa.

[0061] The first electrode plate can be formed by coating a first electrode active material such as graphite or carbon onto a first electrode current collector formed of a metal foil such as copper, copper alloy, nickel, or nickel alloy. The first electrode plate may include a first electrode tab 43 (e.g., a first uncoated portion), which is the area where the first electrode active material is not coated. The first electrode tab 43 can serve as a current flow path between the first electrode plate and the first current collector 41. In some embodiments, when manufacturing the first electrode plate, the first electrode tab 43 is formed by pre-cutting it to protrude to one side of the electrode assembly 40, or the first electrode tab 43 protrudes further (e.g., further or beyond) than the diaphragm to one side of the electrode assembly 40 without separate cutting.

[0062] The second electrode plate can be formed by coating a second electrode active material, such as a transition metal oxide, onto a second electrode current collector formed of a metal foil such as aluminum or an aluminum alloy. The second electrode plate may include a second electrode tab 44 (e.g., a second uncoated portion), which is the area where the second electrode active material is not coated. The second electrode tab 44 can serve as a current flow path between the second electrode plate and the second current collector 42. In some embodiments, during the manufacture of the second electrode plate, the second electrode tab 44 can be formed by pre-cutting it to protrude to the other side (e.g., the opposite side) of the electrode assembly 40, or the second electrode plate can protrude further (e.g., farther or beyond) than the diaphragm to the other side of the electrode assembly 40 without separate cutting.

[0063] The separator prevents or greatly reduces short circuits between the first and second electrode plates while allowing lithium ions to move between them. For example, the separator can be made of polyethylene membrane, polypropylene membrane, polyethylene-polypropylene membrane, etc.

[0064] In some embodiments, the electrode assembly 40 is housed together with the electrolyte in a housing 59.

[0065] In the electrode assembly 40, the first current collector 41 and the second current collector 42 can be welded and connected to the first electrode terminal block 43 extending from the first electrode plate and the second electrode terminal block 44 extending from the second electrode plate, respectively. As described above, in some embodiments where the first electrode terminal block 43 and the second electrode terminal block 44 are located on both sides of the electrode assembly 40, the first current collector 41 and the second current collector 42 are located on both sides of the electrode assembly 40.

[0066] like Figure 3 As shown, the first current collector 41 and the second current collector 42 can be connected to the first terminal 62 and the second terminal 63 respectively via connecting members 67. For example, the connecting members 67 may each have a threaded outer peripheral surface and can be fastened to the first terminal 62 and the second terminal 63 by threaded connection. In another example, the connecting members 67 can also be connected to the first terminal 62 and the second terminal 63 by riveting or welding.

[0067] therefore, Figure 3 The secondary battery shown may have a side-connection tab structure, in which the electrode assembly 40 is arranged such that the first electrode tab 43 and the second electrode tab 44 are located on the right and left sides of the secondary battery. Furthermore, since the first terminal 62 and the second terminal 63 are located on the upper part of the housing 59, they fall within the scope of the top terminal structure. That is, the first electrode tab 43 and the second electrode tab 44 of the electrode assembly 40 are located on the right and left sides of the electrode assembly 40 within the housing 59, and the first current collector 41 and the second current collector 42 are respectively connected to the first electrode tab 43 and the second electrode tab 44, and the first terminal 62 and the second terminal 63, respectively connected to the first current collector 41 and the second current collector 42, are mounted on the outside of the cover plate 61.

[0068] The above references Figures 1 to 3 In the cylindrical and prismatic secondary batteries of the described type, a degassing device for venting gas is shown mounted on cover assembly 50 or 60. However, in some other embodiments, the degassing device may be mounted on another cover assembly or housing located opposite cover assembly 50 or 60. The degassing device mounted as described above in a location opposite cover assembly 50 or 60 will be referred to... Figure 4 describe.

[0069] Figure 4 An exploded perspective view of a prismatic secondary battery according to another embodiment is shown, wherein the degassing device is located on the surface opposite to the cover assembly (e.g., with). Figures 1 to 3 compared to).

[0070] refer to Figure 4 The electrode assembly 74, either core-type or stacked, can be embedded inside the housing 72, and the cover assembly 76 can be located in the upper opening of the housing 72. The cover assembly 76 may include a first cover plate 78, a first terminal 80a, and a second terminal 80b.

[0071] For example, such as Figure 4 As shown, the first electrode tab 82a and the second electrode tab 82b can be located on the upper surface of the electrode assembly 74 inside the housing 72. In another example, the secondary battery may include a side tab structure (e.g., a so-called side tab structure) in which the electrode tabs are located on two side surfaces.

[0072] like Figure 4 As shown, the second cover plate 84 can be installed in the opening at the bottom of the housing 72 (i.e., at the position opposite to the cover assembly 76 or the first cover plate 78). An exhaust port for venting gas, i.e., a gas vent 86, can be formed in the second cover plate 84, and an exhaust element 88 (e.g., a degassing device) formed to rupture due to gas inside the housing 72 can be attached to the gas vent 86 by welding or the like. In another embodiment, the second cover plate 84 may be omitted, the gas vent may be formed directly in the lower surface of the housing 72, and the exhaust element 88 may be attached to the gas vent.

[0073] Figure 5 This illustrates some embodiments according to the present disclosure. Figures 2 to 3 A schematic exploded view of the configuration of the degassing device 66.

[0074] refer to Figure 5 A gas vent 65 may be formed in the cover plate 61 (or in the battery casing or can according to an embodiment), and a degassing device 66 may be incorporated into the gas vent 65. For example, see reference to Figure 5The degassing device 66 can be coupled to the gas vent 65 from bottom to top (e.g., the degassing device 66 can be inserted into the gas vent 65 in a direction oriented from the inside of the housing 59 toward the cover plate 61). The degassing device 66 may include an exhaust plate 90 exposed to the outside of the battery (e.g., facing the outside of the housing 59) through the gas vent 65 and a coupling portion 92 around the exhaust plate 90. In the event of a fire, explosion, or the like in the battery, a portion of the exhaust plate 90 can be opened by gas pressure, thereby serving as a venting element. The coupling portion 92 can be coupled to the outer peripheral edge of the gas vent 65 of the cover plate 61 by welding.

[0075] For example, such as Figure 5 As shown, the vent plate 90 can have a flat plate shape. In another example, the vent plate 90 can have a convex or concave shape facing outwards from the battery (e.g., a shape that protrudes into or from the housing 59). For example, as Figure 5 As shown, the overall shape of the degassing device 66 can be elliptical or approximately elliptical. For example, the same material as the housing 59 or cover 61 can be used as the material of the degassing device 66. In another example, the overall shape of the degassing device 66 can be any suitable shape, and the material of the degassing device 66 can be different from the material of the housing 59 or cover 61.

[0076] Figure 6 This is a detailed plan view of a degassing apparatus 66 according to some embodiments of the present disclosure. Figure 7 It is along Figure 6 A cross-sectional view of line Y-Y' in the diagram.

[0077] refer to Figures 5 to 7 The degassing device 66 of this embodiment may include an exhaust plate 90 and a connecting portion 92 formed on the outer periphery of the exhaust plate 90. For example, the exhaust plate 90 may have an elliptical or approximately elliptical shape. For example, refer to... Figure 6 The mating portion 92 may have an elliptical or approximately elliptical shape and may surround the entire periphery of the exhaust plate 90, as shown in the top view. The mating boundary line 94, indicating the boundary between the exhaust plate 90 and the mating portion 92, may be a virtual line or an actual marking line between the exhaust plate 90 and the mating portion 92. For example, the mating boundary line 94 may correspond to the gas vent 65 of the cover plate 61 (see...). Figure 5 The outline of the gas vent 65 in the cover plate 61 is approximately the same (for example, the boundary line 94 may vertically overlap with the outline of the gas vent 65 in the cover plate 61 and have the same shape and size as the outline of the gas vent 65 in the cover plate 61).

[0078] A notch 100 may be present in the vent plate 90. The notch 100 may include a notch 100a, and the notch 100 may be formed as an outer cutting line defining a portion of the vent plate 90 (i.e., the opening portion 102). The region defined by the outer cutting line of the notch 100 is the opening portion 102, which is the region that is cut from the vent plate 90 and opened (e.g., partially opened) during a battery event. That is, the notch 100a of the notch 100 may be formed as a linear shape thinner than the vent plate 90, so that during an event inside the secondary battery casing (e.g., ...), ... Figure 1 The interior of the 140 shell Figure 2 The interior of the casing 59 or Figure 4 When the gas pressure generated inside the casing 72 exceeds a certain pressure, it ruptures. For example, refer to... Figure 6 The notch 100 can be along Figure 6 The dashed lines in the middle extend to define the corresponding lines. Figure 6 The dotted line in the middle is the outer cutting line, and it can break in response to the pressure inside the secondary battery casing exceeding a predetermined threshold because its notch 100a is thin.

[0079] The opening 102 defined by the notch 100 is not fully open. That is, the degassing device 66 according to some embodiments of this disclosure may include a non-notch 98 that holds one side of the opening 102 so that the opening 102 does not separate from the connecting portion 92 even when the notch 100 is cut (e.g., not fully separated) (e.g., compared to a comparative venting structure that ruptures and fully opens when the gas pressure inside the battery exceeds a certain pressure). For example, refer to... Figure 6 The opening portion 102 can be separated from the vent plate 90 along the notch portion 100, while the non-notch portion 98 can remain attached to the connecting portion 92. The non-notch portion 98 can be within the vent plate 90, excluding the notch 100a, and can be connected to the vent plate 90 when the opening portion 102 is partially open, such that the opening portion 102, which is cut and partially opened along the outer cutting line during an event, does not separate from the vent plate 90. Accordingly, the opening portion 102 can be opened by rotation about the non-notch portion 98 (e.g., it can be opened by rotation about the non-notch portion 98). In this way, by using a rotational opening system for the opening portion 102 within the region of the vent plate 90, internal gases can be released when a battery event occurs, while eliminating or completely minimizing the entry of external foreign objects into the battery housing (e.g., compared to a completely ruptured vent).

[0080] Furthermore, the opening 102 can be formed to have various areas and profiles within the area of ​​the exhaust plate 90, thereby ensuring design freedom for exhaust components suitable for various battery characteristics. That is, as... Figure 6 As shown, the outer cutting line of the opening portion 102 defined by the notch portion 100 can be variably defined by the notch portion 100 to have various areas and profiles within the region of the exhaust plate 90. Figure 6 In this case, the opening portion 102 is defined to have a length L3, which is less than the length L2 of the exhaust plate 90 (for example, the length L2 may be the length of the elliptical or approximately elliptical exhaust plate 90 along its long axis).

[0081] like Figure 6 As shown, the non-notched portion 98 can connect one side of the opening portion 102 to the mating boundary line 94, which is the connection between the exhaust plate 90 and the mating portion 92. For this purpose, one side of the non-notched portion 98 can be located on or adjacent to the mating boundary line 94, and the notched portion 100 can extend from the other side of the non-notched portion 98, spaced a certain distance from that side, to form the opening portion 102. This is in... Figure 7 It is shown in detail in the text.

[0082] refer to Figure 6 and Figure 7 First, the non-notched portion 98 will be described. The non-notched portion 98 may include a first boundary line 99 and a second boundary line 104. The first boundary line 99 is connected to the mating portion 92 via a mating boundary line 94, and the second boundary line 104 is located on the side of the non-notched portion 98 opposite to the mating portion 92, spaced apart from the first boundary line 99 by a predetermined distance. Figure 6 As shown, the notch portion 100 can be connected to the second boundary line 104 of the non-notch portion 98. For example, the first boundary line 99 and the second boundary line 104 can also be connected due to... Figure 6 The projections are designated as points and referred to as the first point and the second point, respectively. The distance between the first boundary line 99 and the second boundary line 104 of the non-notched portion 98, i.e., the width w of the non-notched portion 98, can be within a distance corresponding to 10% of the width L1 of the exhaust plate 90 (see...). Figure 6 and Figure 7 Therefore, the distance between the starting point of the notch portion 100 that defines the outer cutting line of the opening portion 102 and the connecting portion 92 can also be within 10% of the width L1 of the exhaust plate 90 (for example, the width L1 can be the length of the elliptical or approximately elliptical exhaust plate 90 along its short axis).

[0083] In this way, since the starting point of the notch 100 is located on or adjacent to the bonding boundary line 94, which is the outermost part of the exhaust plate 90, the area of ​​the opening 102 can be maximized to be close to the area of ​​the exhaust plate 90. (On the other hand, in the case of a comparative rupture-type opening exhaust port, the entire area of ​​the exhaust plate is not opened, and only the area in which the rupture line is formed is torn and partially opened.) Therefore, the opening 102 can be designed differently for large-capacity batteries and small-capacity batteries, thereby giving gas emission performance optimized for battery characteristics.

[0084] like Figure 7 As shown, a groove 98a can be formed in the surface of the vent plate 90 between the first boundary line 99 and the second boundary line 104 of the non-notched portion 98. The groove 98a allows the non-notched portion 98 to serve as a rotational axis when the opening portion 102 is opened due to gas inside the battery (see...). Figure 8 (and related descriptions). Preferably, the depth of the groove 98a is less than the depth of the notch in the recessed portion 100 (or the depth of the notch 100a). This is because the groove 98a should not rupture due to gas inside the battery. For example, refer to... Figure 7 The groove 98a and the recess 100a may be formed in the lower surface of the exhaust plate 90 (e.g., in the surface of the exhaust plate 90 facing the electrode assembly). In another example, the groove and the recess may also be formed in the upper surface of the exhaust plate 90.

[0085] For example, refer to Figure 7 The notch 100a of the recessed portion 100 and the groove 98a of the non-recessed portion 98 can be formed in the same surface of the exhaust plate 90. In another example, the notch of the recessed portion 100 and the groove of the non-recessed portion 98 can be formed on opposite surfaces of the exhaust plate 90.

[0086] like Figure 7 As shown, the non-notch portion 98 of the degassing device 66 according to some other embodiments of the present disclosure may additionally include a protrusion 98b formed on the surface of the exhaust plate 90 opposite to the surface forming the groove 98a. For example, refer to Figure 7 The protrusion 98b and the groove 98a can have the same shape and can overlap each other vertically. When the non-notched portion 98 includes both the groove 98a and the protrusion 98b, the role of the non-notched portion 98 as the axis of rotation of the opening portion 102 becomes more pronounced. Furthermore, as... Figure 7 As shown, the distance between the bottom of the groove 98a and the peak of the protrusion 98b, that is, the thickness t2 of the non-recessed portion 98, can be approximately the same as the thickness t1 of the exhaust plate 90.

[0087] exist Figure 6 and Figure 7In the accompanying drawings, reference numeral 96 indicates the outer contour of the connecting portion 92 of the degassing device 66. For example, referring to... Figure 6 and Figure 7 The shape of the mating portion 92 can be elliptical or approximately elliptical. For example, the outline of the exhaust plate 90, i.e., the mating boundary line 94, can have an elliptical or approximately elliptical shape. The shape of the exhaust plate 90 can depend on the gas discharge port 65 formed in the counterpart (cover or housing) (see...). Figure 5 The shape of the degassing device 66 is attached to the corresponding object.

[0088] Figure 8 This example illustrates a state where the notch portion 100 is cut due to the gas pressure inside the battery and the opening portion 102 is open.

[0089] refer to Figure 8 As described above, the opening 102 can be opened like a door using the groove (and protrusion) between the first boundary line 99 and the second boundary line 104 of the non-notch portion 98 as an axis of rotation. Therefore, gas inside the battery can be released when an event occurs. Unlike comparative rupture-type venting devices, the opening 102 can function as a cover to eliminate the possibility of unpredictable side effects caused by external foreign objects entering the battery.

[0090] Figures 9A to 9C Examples of various shapes and areas of the opening portion 102 are shown.

[0091] For example, refer to Figure 9A The opening 102 can have a relatively small area, and the dimensions of the non-notch 98 can be small to correspond to the area of ​​the opening 102. For example, the length of the opening 102 can be equal to or less than half the length of the elliptical or approximately elliptical exhaust plate 90 along its long axis.

[0092] For example, refer to Figure 9B The opening 102 may have a maximum area close to that of the exhaust plate, and the non-notched portion 98 may extend most or all of a straight portion along one side of the opening 102. For example, the opening 102 may largely overlap with the exhaust plate. In addition, the two ends of the opening 102 protrude relative to the two ends of the non-notched portion 98.

[0093] For example, refer to Figure 9C The length of the non-notched portion 98 may extend along most or all of the straight portion on one side of the opening portion 102, and the opening portion 102 in Figure 9C The area in can be determined by the two ends of the opening 102. Figure 9C The two ends of the middle and non-notched portions 98 are aligned and compared to the middle. Figure 9B Small and medium-sized and compared to Figure 9ASun Yat-sen University.

[0094] In the example above, the shape and area of ​​the opening 102 defined by the recess 100 and the length of the non-recess 98 can be designed in various ways within the area of ​​the exhaust plate 90 to achieve an appropriate exhaust effect according to the characteristics of the battery.

[0095] Figure 10A and Figure 10B An example is illustrated where the notch portion 100 is asymmetrically formed relative to the non-notch portion 98 to alter the degassing direction. For example, the outer cutting line defined by the notch portion 100 may include at least one of a straight line and a curve. For example, the straight line included in the outer cutting line defined by the notch portion 100 may include at least one of a vertical line and an oblique line relative to the extending direction of the non-notch portion 98.

[0096] For example, refer to Figure 10A The notch portion 100 may include a straight notch 101a vertically connected to the left end of the non-notch portion 98 (e.g., the linear shape of the notch 100a of the notch portion 100 may include a vertical line relative to the extending direction of the non-notch portion 98). The straight notch 101a may not be formed to have a symmetrical shape with the portion of the notch portion 100 connected to the right end of the non-notch portion 98. For example, the notch portion 100 may also include an oblique notch 101b connecting the end of the straight notch 101a opposite to the non-notch portion 98 to the right end of the non-notch portion 98 (e.g., the linear shape of the notch 100a of the notch portion 100 may also include an oblique line relative to the extending direction of the non-notch portion 98). Therefore, in Figure 10A In this case, degassing can be performed in the approximately ten o'clock direction due to the angle of the oblique notch 101b.

[0097] In another example, refer to Figure 10B The notch portion 100 may include a straight notch 103a vertically connected to the right end of the non-notch portion 98 (e.g., the linear shape of the notch 100a of the notch portion 100 may include a vertical line relative to the extending direction of the non-notch portion 98). The straight notch 103a may not be formed to have a symmetrical shape with the portion of the notch portion 100 connected to the left end of the non-notch portion 98. For example, the notch portion 100 may also include an oblique notch 103b connecting the end of the straight notch 103a opposite to the non-notch portion 98 to the left end of the non-notch portion 98 (e.g., the linear shape of the notch 100a of the notch portion 100 may also include an oblique line relative to the extending direction of the non-notch portion 98). Therefore, in Figure 10B In this case, degassing can be performed in the approximately two o'clock direction due to the angle of the oblique notch 103b.

[0098] By designing the shape of the opening portion 102 in this way (e.g., asymmetrical with respect to the center of the exhaust plate 90), the direction of degassing can be controlled to be oriented in the desired direction.

[0099] Figure 11A and Figure 11B An example is shown where the notch portion 100 is formed solely by a straight line. In the above... Figure 9A and Figure 9B In the notch, the notch portion 100 is formed only by curves (e.g., the outer cutting line defined by the notch portion 100 includes only straight lines), and... Figure 9C In this notch, the notch portion 100 is formed by a combination of straight lines and curves (e.g., the outer cutting line defined by the notch portion 100 includes both straight lines and curves). When the notch portion 100 is formed by straight lines rather than curves, the machining performance in terms of equipment or time is excellent. Figure 11A and Figure 11B An example of notch 100 being machined using only straight lines.

[0100] Figures 12A to 12D Various examples of degassing devices 66 with openings 102 of various shapes are shown. For example, the notch portion 100 in... Figure 12A The opening can have a circular outline (instead of an elliptical or near-elliptical outline). In other examples, the opening 102 can have a pentagonal shape, a quadrilateral shape, and a triangular shape (in order of preference). Figures 12B to 12D (The shapes listed in the diagram) can be formed inside the circular vent plate 90. For example, these degassing devices 66 with circular shapes can be manufactured in small sizes and therefore can be applied to relatively small batteries. In another example, a large number of these circular degassing devices 66 can be applied to large batteries so that each part of the battery (e.g., different parts) can be degassed.

[0101] Figure 13 and Figure 14 Example Figure 7 Modified implementation examples.

[0102] For example, refer to Figure 7 The connecting portion 92 at the contour line 96 may have a height (e.g., may extend) higher than the surface (e.g., the upper surface) of the exhaust plate 90, such that the exhaust plate 90 descends further than the cover plate 61 (e.g., the connecting portion 92 may define a step or predetermined distance between the upper surface of the exhaust plate 90 and the lower surface of the cover plate 61). In another example, refer to... Figure 13 The surface of the connecting portion 92 at the contour line 96 (e.g., the upper surface) can be coplanar with the surface of the exhaust plate 90 (e.g., the upper surface), so that after assembly with the cover plate 61, the exhaust plate 90 can be directly located below the cover plate 61. For example, refer to Figure 13The surface of the connecting portion 92 (e.g., the upper surface) can be coplanar with and extend together with the surface of the vent plate 90 (e.g., the upper surface), therefore the upper surface of the vent plate 90 can be coplanar with the lower surface of the cover plate 61. Depending on the battery structure, the shape can be derived from... Figure 7 The shape of the joint and Figure 13 Choose from the shapes of the combined parts.

[0103] For example, refer to Figure 7 The groove of the non-recessed portion 98 and the recess 100a of the recessed portion 100 can be formed on the lower surface of the exhaust plate 90. In another example, refer to Figure 14 The groove in the non-recessed portion 98 and the recess in the recessed portion 100 can be formed on the upper surface of the exhaust plate 90. Because in Figure 7 and Figure 14 In this case, the cutting characteristics of the notched portion 100 and the rotation axis functional characteristics of the non-notched portion 98 differ, therefore the notched portion 100 and the non-notched portion 98 can be appropriately and selectively applied according to the characteristics of the battery. Figure 7 and Figure 14 In the process, the groove of the non-recessed portion 98 and the recess of the recessed portion 100 are formed on the same surface of the exhaust plate 90, but the groove of the non-recessed portion 98 and the recess of the recessed portion 100 can also be formed on different surfaces of the exhaust plate 90.

[0104] The following describes a method for manufacturing a secondary battery including the above-described degassing device. A method for manufacturing a secondary battery according to some embodiments of this disclosure may include: forming a gas vent 65 in one of a housing and a cover; manufacturing a degassing device 66 configured to vent gas inside the housing in the event of an event; and attaching the degassing device 66 to the gas vent 65, wherein manufacturing the degassing device 66 may include: forming an exhaust plate 90 exposed to the outside of the housing through the gas vent 65 and a bonding portion 92 around the exhaust plate 90; providing a notch 100 defining an outer cutting line of an opening portion through which the exhaust plate 90 partially opens in the event of an event; and providing a non-notch 98 such that the opening portion, cut and opened along the outer cutting line in the event of an event, does not separate from the exhaust plate 90.

[0105] In some embodiments, providing a non-notched portion 98 may include forming a first boundary line 99 and a second boundary line 104, the first boundary line 99 being connected to the joining portion 92 and the second boundary line 104 being located on the side opposite to the joining portion 92 and spaced apart from the first boundary line 99, and providing a notched portion 100 may include forming a notch that is connected to the second boundary line 104 of the non-notched portion 98.

[0106] In some embodiments, providing a notch 100 may include altering the outer cutting line of the opening 102 defined by the notch 100 within the region of the exhaust plate 90.

[0107] In some embodiments, providing a non-notched portion 98 may include forming a groove in the surface of the exhaust plate 90.

[0108] In some embodiments, providing the non-notched portion 98 may include forming the groove to have a depth smaller than the notched depth of the notched portion 100.

[0109] In some embodiments, providing a non-notch portion 98 may further include forming a protrusion on the surface of the exhaust plate 90 opposite to the surface in which the groove is formed.

[0110] In some embodiments, providing a notch 100 may include defining the outer cutting line of the opening 102 as at least one of a straight line and a curve.

[0111] In some embodiments, defining the outer cutting line of the opening portion 102 as including a straight line may include defining the outer cutting line of the opening portion 102 as including at least one of a vertical line and a diagonal line relative to the extension direction of the non-notch portion 98.

[0112] Suitable materials that can be used in secondary batteries according to embodiments of the present disclosure will be described below.

[0113] As the positive electrode active material, compounds capable of reversibly inserting / deintercalating lithium (e.g., lithiated intercalation compounds) can be used. For example, at least one of lithium and a composite oxide of a metal selected from cobalt, manganese, nickel, and combinations thereof can be used.

[0114] The composite oxide can be a lithium transition metal composite oxide, and examples of it can include lithium nickel oxide, lithium cobalt oxide, lithium manganese oxide, lithium iron phosphate compound, cobalt-free nickel manganese oxide, or combinations thereof.

[0115] For example, compounds represented by any of the following molecular formulas can be used: Li a A 1-b X b O 2-c D' c (0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.05); Li a Mn 2-b X b O 4-c D' c (0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.05); Li a Ni 1-b-c Cob X c O 2-α D' α (0.90≤a≤1.8,0≤b≤0.5,0≤c≤0.5,0<α<2); Li a Ni 1-b- c Mn b X c O 2-α D α (0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.5, 0<α<2); Li a Ni b Co c L 1 d G e O2 (0.90≤a≤1.8, 0≤b≤0.9, 0≤c≤0.5, 0≤d≤0.5, 0≤e≤0.1); Li a NiG b O2 (0.90≤a≤1.8, 0.001≤b≤0.1); Li a CoG b O2 (0.90≤a≤1.8, 0.001≤b≤0.1); Li a Mn 1-b G b O2 (0.90≤a≤1.8, 0.001≤b≤0.1); Li a Mn2G b O4 (0.90≤a≤1.8, 0.001≤b≤0.1); Li a Mn 1-g G g PO4 (0.90≤a≤1.8, 0≤g≤0.5); Li (3-f) Fe2(PO4)3 (0≤f≤2); and Li a FePO4 (0.90≤a≤1.8).

[0116] In the above molecular formulas: A can be Ni, Co, Mn, or a combination thereof; X can be Al, Ni, Co, Mn, Cr, Fe, Mg, Sr, V, rare earth elements, or a combination thereof; D can be O, F, S, P, or a combination thereof; G can be Al, Cr, Mn, Fe, Mg, La, Ce, Sr, V, or a combination thereof; and L 1 It can be Mn, Al, or a combination thereof.

[0117] The positive electrode for a lithium secondary battery may include a substrate and a positive electrode active material layer formed on the substrate. The positive electrode active material layer may include a positive electrode active material, and may further include a binder and / or a conductive material.

[0118] Based on 100 wt% of the positive electrode active material layer, the content of the positive electrode active material may be in the range of about 90 wt% to about 99 wt%, and based on 100 wt% of the positive electrode active material layer, the contents of the binder and the conductive material may be in the range of about 0.5 wt% to about 5 wt% respectively.

[0119] The substrate may be aluminum (Al).

[0120] The negative electrode active material may include a material capable of reversibly intercalating / deintercalating lithium ions, lithium metal, a lithium metal alloy, a material capable of doping and dedoping lithium, or a transition metal oxide.

[0121] The material capable of reversibly intercalating / deintercalating lithium ions may be a carbon negative electrode active material, which may include, for example, crystalline carbon, amorphous carbon, or a combination thereof. Examples of crystalline carbon may include graphite such as natural graphite or artificial graphite, and examples of amorphous carbon may include soft carbon, hard carbon, pitch carbide, mesophase pitch carbide, sintered coke, etc.

[0122] A Si negative electrode active material or a Sn negative electrode active material may be used as the material capable of doping and dedoping lithium. The Si negative electrode active material may be silicon, a silicon-carbon composite, SiO x (0 < x ≤ 2), a Si alloy, or a combination thereof.

[0123] The silicon-carbon composite may be a composite of silicon and amorphous carbon. According to one embodiment, the silicon-carbon composite may be in the form of silicon particles and amorphous carbon coated on the surface of the silicon particles.

[0124] The silicon-carbon composite may further include crystalline carbon. For example, the silicon-carbon composite may include a core containing crystalline carbon and silicon particles and an amorphous carbon coating on the surface of the core.

[0125] The negative electrode for a lithium secondary battery may include a substrate and a negative electrode active material layer provided on the substrate. The negative electrode active material layer may include a negative electrode active material, and may further include a binder and / or a conductive material.

[0126] For example, the negative electrode active material layer may include about 90 wt% to about 99.5 wt% of the negative electrode active material, about 0.5 wt% to about 5 wt% of the binder, and about 0 wt% to about 5 wt% of the conductive material.

[0127] Non-aqueous binders, aqueous binders, dry binders, or combinations thereof can be used as binders. When an aqueous binder is used as a negative electrode binder, it may further include a cellulose compound capable of imparting viscosity.

[0128] As the negative electrode substrate, one can be selected from copper foil, nickel foil, stainless steel foil, titanium foil, nickel foam, copper foam, polymer substrate coated with conductive metal, and combinations thereof.

[0129] Electrolytes used in lithium secondary batteries may include non-aqueous organic solvents and lithium salts.

[0130] Non-aqueous organic solvents serve as a medium through which ions participating in the electrochemical reactions of the battery can move.

[0131] Non-aqueous organic solvents can be carbonates, esters, ethers, ketones, alcohols, or aprotic solvents, and can be used alone or in combination of two or more.

[0132] In addition, when using carbonate solvents, a mixture of cyclic carbonates and chain carbonates can be used.

[0133] Depending on the type of lithium-ion secondary battery, a separator can be present between the first electrode plate (e.g., the negative electrode) and the second electrode plate (e.g., the positive electrode). Polyethylene, polypropylene, polyvinylidene fluoride, or multilayer films comprising two or more of these materials can be used as the separator.

[0134] The diaphragm may include a porous substrate and a coating on one or both surfaces of the porous substrate, the coating comprising an organic material, an inorganic material, or a combination thereof.

[0135] Organic materials may include polyvinylidene fluoride polymers or (meth)acrylic acid polymers.

[0136] Inorganic materials may include, but are not limited to, inorganic particles selected from Al2O3, SiO2, TiO2, SnO2, CeO2, MgO, NiO, CaO, GaO, ZnO, ZrO2, Y2O3, SrTiO3, BaTiO3, Mg(OH)2, boehmite and combinations thereof.

[0137] Organic and inorganic materials can be mixed in a coating, or the coating may be a combination of an organic material coating and an inorganic material coating stacked on top of each other.

[0138] Figure 15This is a perspective view of a secondary battery module in which secondary batteries according to embodiments of the present disclosure are arranged. As the capacity of secondary batteries used to power electric vehicles and the like increases, secondary battery modules can be manufactured by arranging multiple secondary battery cells (or multiple secondary batteries) laterally and / or longitudinally and connecting them together. Multiple secondary batteries can be arranged in a space defined by a pair of facing end plates 68a and 68b and a pair of facing side plates 69a and 69b. The secondary batteries can be arranged in a certain manner (orientation) and number to obtain desired voltage and current specifications.

[0139] Figure 16 This is a perspective view of a battery pack 70 according to an embodiment of the present disclosure. Reference Figure 16 The battery pack 70 may include components and a housing to house the components, with individual batteries (or secondary batteries) electrically connected to the components. In the accompanying drawings, for illustrative purposes, components including busbars, cooling units, external terminals for electrical connection to the batteries, etc., are not shown. The battery pack 70 may be mounted on (or in) a vehicle. For example, the vehicle may be an electric vehicle, a hybrid vehicle, or a plug-in hybrid vehicle. The vehicle may be, for example, a four-wheeled vehicle or a two-wheeled vehicle.

[0140] Figure 17 Shown on its undercarriage including Figure 16 The vehicle shown has battery pack 70. (Reference) Figure 17 The vehicle can operate by receiving power from the battery pack 70 (e.g., it can be driven by receiving power from the battery pack 70).

[0141] By summarizing and reviewing, this disclosure relates to improving a degassing device to control the amount and direction of gas emissions generated inside a battery, thereby achieving effective degassing. Specifically, according to this disclosure, the degassing device may include an exhaust plate and a non-notched portion. The exhaust plate has an opening region defined in shape and area by the notched portion, and the non-notched portion has lengths designed differently within the region of the exhaust plate, thereby achieving an appropriate degassing effect according to the characteristics of the battery. Furthermore, the shape of the outer cutting line of the opening region defined by the notched portion can be variably designed, thus allowing the degassing direction to be controlled in a desired direction. Further, the outer cutting line of the opening region defined by the notched portion may include a straight line, thereby improving the processability or machinability of the degassing device during manufacturing.

[0142] The aspects and features of this disclosure are not limited to those described above, and those skilled in the art will clearly understand from the foregoing description of this disclosure other aspects and features not specifically mentioned herein.

[0143] Example embodiments have been disclosed herein. While specific terminology has been used, it is used and interpreted in a general and descriptive sense only and not for limiting purposes. In some cases, as will be apparent to those skilled in the art at the time of filing this application, unless otherwise specifically stated, features, characteristics, and / or elements described in connection with particular embodiments may be used alone or in combination with features, characteristics, and / or elements described in connection with other embodiments. Therefore, those skilled in the art will understand that various changes in form and detail may be made without departing from the spirit and scope set forth in the claims of this invention.

Claims

1. A secondary battery, comprising: The housing and electrode assembly are housed within the housing; Cover plate, attached to the housing; as well as A degassing device, located on one of the housing and the cover plate, the degassing device comprising: An exhaust plate is exposed to the outside of the housing; The connecting portion is located around the exhaust plate and is connected to one of the housing and the cover plate; A notch portion, in the exhaust plate, the notch portion includes a notch and defines an outer cutting line of an opening portion of the exhaust plate, and the opening portion is partially openable in the event of an event; and The non-notched portion, in the exhaust plate, does not include the notch and connects the opening portion to the exhaust plate when the opening portion is partially open.

2. The secondary battery according to claim 1, wherein: The non-notched portion includes a first boundary line and a second boundary line. The first boundary line connects to the joining portion, and the second boundary line is located on the side of the non-notched portion opposite to the joining portion, spaced apart from the first boundary line by a predetermined distance. The notched portion is connected to the second boundary line of the non-notched portion.

3. The secondary battery according to claim 2, wherein the distance between the first boundary line and the second boundary line of the non-notched portion is 10% or less of the width of the exhaust plate.

4. The secondary battery according to claim 1, wherein the outer cutting line of the opening portion is variably defined by the recessed portion within the region of the exhaust plate.

5. The secondary battery according to claim 1, wherein the non-recessed portion comprises a groove in the surface of the vent plate.

6. The secondary battery according to claim 5, wherein the notch in the recessed portion and the groove in the non-recessed portion are on the same surface of the exhaust plate.

7. The secondary battery according to claim 5, wherein the notch in the recessed portion and the groove in the non-recessed portion are on opposite surfaces of the exhaust plate.

8. The secondary battery according to claim 5, wherein the groove in the non-notched portion has a depth smaller than the depth of the notch in the notched portion.

9. The secondary battery of claim 5, wherein the non-notch portion further includes a protrusion on the surface of the vent plate, the protrusion being on the surface of the vent plate opposite to the surface in which the groove is formed.

10. The secondary battery according to claim 9, wherein the distance between the bottom of the groove in the non-recessed portion and the peak of the protrusion is equal to the thickness of the exhaust plate.

11. The secondary battery of claim 1, wherein the outer cutting line defined by the notch portion comprises at least one of a straight line and a curve.

12. The secondary battery of claim 11, wherein the straight line of the outer cleavage defined by the notch portion includes an oblique line.

13. A method for manufacturing a secondary battery, the method comprising: A gas vent is formed in one of the housing and the cover plate; Manufacture a degassing device, the degassing device being configured to release gas inside the housing in the event of an event; as well as The degassing device is integrated into the gas discharge port. The degassing device is manufactured by: An exhaust plate is formed such that the exhaust plate is exposed to the outside of the housing through the gas discharge port, and a joint portion is formed around the exhaust plate; A notched portion providing an outer cut line defining an opening portion, the vent plate partially opening through the opening portion in the event of an event; and A non-notched portion is provided such that the opening portion, which is cut and partially opened along the outer cutting line when an event occurs, does not separate from the exhaust plate.

14. The method of claim 13, wherein: The non-notched portion includes forming a first boundary line and a second boundary line, the first boundary line being connected to the joining portion, and the second boundary line being located on the side of the non-notched portion opposite to the joining portion and spaced apart from the first boundary line. The notched portion includes a notch forming a second boundary line connected to the non-notched portion.

15. The method of claim 13, wherein providing the notch portion includes the outer cutting line of the opening portion variably defined by the notch portion within the region of the exhaust plate.

16. The method of claim 13, wherein providing the non-notched portion comprises forming a groove in the surface of the exhaust plate.

17. The method of claim 16, wherein providing the non-notched portion comprises forming the groove to have a depth smaller than the notch depth of the notched portion.

18. The method of claim 16, wherein providing the non-notch portion further comprises forming a protrusion on the surface of the exhaust plate opposite to the surface in which the groove is formed.

19. The method of claim 13, wherein providing the notch portion comprises defining the outer cutting line of the opening portion using at least one of a straight line and a curve.

20. The method of claim 19, wherein the outer cutting line defining the opening portion using the straight line includes the outer cutting line defining the opening portion using an oblique line.

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