Secondary battery

Abstract

The present disclosure provides a secondary battery. The secondary battery includes an electrode assembly, a case in which the electrode assembly is accommodated, the case having an exhaust hole on at least one side thereof, and an exhaust portion disposed in the exhaust hole, the exhaust portion including a polymer layer and a fragile layer on the polymer layer.

Description

Technical Field

[0001] This disclosure relates to secondary batteries, and more specifically, to secondary batteries including an exhaust section. Background Technology

[0002] Unlike primary batteries, which are not designed for (re)charging, secondary (or rechargeable) batteries are designed to be discharged and recharged. Low-capacity secondary batteries are used in portable small electronic devices such as smartphones, feature phones, laptops, digital cameras, and camcorders, while high-capacity secondary batteries are widely used as power sources for motors in hybrid and electric vehicles, as well as for storing electricity (e.g., household and / or utility-scale power storage). Secondary batteries typically consist of an electrode assembly containing positive and negative electrodes, a housing, and electrode terminals connected to the electrode assembly.

[0003] The information disclosed in this background section is intended to enhance the understanding of the background of this disclosure, and therefore may contain information that does not constitute related (or prior art). Summary of the Invention

[0004] According to embodiments of the present disclosure, a secondary battery may include an electrode assembly, a housing that houses the electrode assembly and has an exhaust port formed on at least one side, and an exhaust portion disposed in the exhaust port, wherein the exhaust portion may include a polymer layer and a brittle layer disposed on the polymer layer.

[0005] In some embodiments, the polymer layer may include at least one of polypropylene, polyimide, polyvinyl chloride, polytetrafluoroethylene, polyurethane, polyamide, and combinations thereof.

[0006] In some embodiments, the brittle layer may include at least one of glass, ceramic, silicon, limestone, aluminum oxide (Al2O3), indium tin oxide (ITO), magnesium alloy, and combinations thereof.

[0007] In some embodiments, the lower end of one side of the housing that contacts the vent may include a first stepped portion and a second stepped portion, the second stepped portion being connected to the first stepped portion and located at a level higher than the upper surface of the first stepped portion.

[0008] In some embodiments, the polymer layer is bonded to the first step portion.

[0009] In some embodiments, the brittle layer is bonded to the second step portion.

[0010] In some embodiments, the first stepped portion may include a first surface and a second surface, the first surface being connected to and perpendicular to the lower surface of the housing in contact with the vent hole on one side, the second surface being connected to and parallel to the lower surface, and the length of the second surface along the longitudinal direction of the housing being greater than or equal to 2 mm.

[0011] In some embodiments, the second stepped portion may include a third surface connected to the second surface and perpendicular to the lower surface, and a fourth surface connected to the third surface and parallel to the lower surface, wherein the length of the fourth surface along the longitudinal direction of the housing is greater than or equal to 1 mm.

[0012] In some embodiments, at least one side of the housing may include a cover plate, and an exhaust portion is formed in the cover plate.

[0013] In some embodiments, the secondary battery further includes an adhesive layer disposed between the polymer layer and the brittle layer.

[0014] In some embodiments, the adhesive layer may include at least one of acrylic adhesives, rubber adhesives, silicone adhesives, epoxy adhesives, polyurethane adhesives, cyanoacrylate adhesives, polyvinyl chloride adhesives, hot melt adhesives, and combinations thereof.

[0015] In some embodiments, the thickness of the polymer layer is less than 1 mm.

[0016] In some embodiments, the secondary battery may include an electrode assembly, a housing that houses the electrode assembly and has an exhaust port formed on at least one side, and an exhaust portion disposed in the exhaust port, wherein a protrusion structure or a groove structure is formed on the upper end of at least one side of the housing that contacts the exhaust port, and the exhaust portion may include a polymer layer, an adhesive layer disposed on the polymer layer, and a brittle layer disposed on the adhesive layer.

[0017] In some embodiments, the protrusion structure is formed by a portion of the upper end of at least one side of the housing that contacts the vent hole extending parallel to the lower surface of at least one side of the housing toward the vent hole.

[0018] In some embodiments, the length of the protrusion along the longitudinal direction of the housing is 1 mm to 10 mm.

[0019] In some embodiments, the groove structure is formed by an inward recess of a portion of the upper end of at least one side of the housing that contacts the vent.

[0020] In some embodiments, the length of the groove structure along the longitudinal direction of the housing is 1 mm to 10 mm.

[0021] In some embodiments, the lower end of at least one side of the housing that contacts the vent may include a stepped portion.

[0022] In some embodiments, the polymer layer is bonded to the stepped portion.

[0023] In some embodiments, the brittle layer is bonded to the inner surface facing the vent hole on at least one side of the housing. Attached Figure Description

[0024] The following accompanying drawings illustrate embodiments of the present disclosure, and together with the detailed description of the present disclosure, aspects and features of the present disclosure are further described. Therefore, the present disclosure should not be construed as limited to the drawings:

[0025] Figure 1 A perspective view of a secondary battery according to an embodiment of the present disclosure is shown.

[0026] Figure 2 A perspective view of a secondary battery according to another embodiment of the present disclosure is shown.

[0027] Figure 3 It is along Figure 1 The cross-sectional view taken by line a-a'.

[0028] Figure 4 An exhaust portion of a secondary battery according to an embodiment of the present disclosure is shown.

[0029] Figure 5 The surface of the casing of a secondary battery according to an embodiment of the present disclosure is shown.

[0030] Figure 6 The surface of the casing of a secondary battery having an venting portion according to an embodiment of the present disclosure is shown.

[0031] Figure 7 The surface of the casing of a secondary battery according to another embodiment of the present disclosure is shown.

[0032] Figure 8 The surface of the casing of a secondary battery according to yet another embodiment of the present disclosure is shown.

[0033] Figure 9 This is a top view showing the surface of the casing of a secondary battery according to an embodiment of the present disclosure.

[0034] Figure 10 This is a top view showing the surface of the casing of a secondary battery according to another embodiment of the present disclosure.

[0035] Figure 11 This is a top view showing the surface of the casing of a secondary battery according to yet another embodiment of the present disclosure. Detailed Implementation

[0036] In the following, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. The terms or words used in this specification and claims should not be construed as limited to their ordinary or dictionary meanings, and should be interpreted in accordance with the principle that the inventor can be his / her own lexicographer to appropriately define the concepts of the terms so as to best interpret his / her invention, and are consistent with the technical ideas of the present disclosure.

[0037] The embodiments described in this specification and the configurations shown in the accompanying drawings are merely some embodiments of this disclosure and do not represent all technical ideas, aspects, and features of this disclosure. Therefore, it should be understood that various equivalents and modifications may exist to replace or modify the embodiments described herein at the time of filing this application.

[0038] It should be understood that when an element or layer is referred to as being “between” two layers, it can be the only layer between the two layers, or one or more intermediate layers may exist. It should be understood that when an element or layer is referred to as being “on”, “connected to”, or “bonded to” another element or layer, it can be directly on, directly connected to, or directly bonded to the other element or layer, or one or more intermediate elements or layers may exist. When an element or layer is referred to as being “directly on”, “directly connected to”, or “directly bonded to” another element or layer, no intermediate elements or layers exist. For example, when a first element is described as being “bonded” or “connected” to a second element, the first element can be directly bonded to or connected to the second element, or the first element can be indirectly bonded to or connected to the second element via one or more intermediate elements.

[0039] In the accompanying drawings, the dimensions of various elements, layers, etc., may be exaggerated for clarity. The same reference numerals denote 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, when describing embodiments of this disclosure, the use of “may” refers to “one or more embodiments of this disclosure.” Expressions such as “at least one of…” and “any one of…” modify the entire column of elements, not individual elements within that column, when following a column of elements. When a column of elements A, B, and C is specified using 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 consisting of A, B, and C,” or “at least one selected from 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 terms “use,” “using…,” and “being used” may be considered synonymous with the terms “utilize,” “using…,” and “being exploited,” respectively. As used herein, the terms “substantially,” “about,” and similar terms are used as approximations rather than terms of degree, intended to describe the inherent biases of measurements or calculations that would be recognized by one of ordinary skill in the art.

[0040] It will be understood that although the terms first, second, third, etc., may be used herein to describe various elements, components, regions, layers, and / or portions, these elements, components, regions, layers, and / or portions should not be limited by these terms. These terms are used to distinguish one element, component, region, layer, or portion from another element, component, region, layer, or portion. Therefore, the first element, component, region, layer, or portion discussed below may be referred to as a second element, component, region, layer, or portion without departing from the teachings of the exemplary embodiments.

[0041] For ease of description, spatial relation terms such as “below,” “under,” “down,” “above,” and “above” are used herein to describe the relationship between one element or feature and another element or feature as shown in the figure. It will be understood that, in addition to the orientation depicted in the figure, spatial relation terms are also intended to cover different orientations of the device in use or operation. For example, if the device in the figure is flipped, the element described as “below” or “under” other elements or features will be oriented “above” or “above” other elements or features. Therefore, the term “below” can cover both above and below orientations. The device may be oriented in other ways (rotated 90 degrees or in other orientations), and the spatial relation descriptors used herein should be interpreted accordingly.

[0042] The terminology used herein is for describing embodiments of the present disclosure and is not intended to limit the disclosure. As used herein, the singular form “a” is also intended to include the plural form unless the context clearly indicates otherwise. It will be further understood that the terms “comprising,” “including,” “including,” and / or “containing” as used in this specification indicate the presence of stated features, numbers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, numbers, steps, operations, elements, components, and / or groups thereof.

[0043] Furthermore, any numerical range disclosed and / or described herein is intended to include all subranges containing the same numerical precision within said range. For example, the range “1.0 to 10.0” is intended to include all subranges between (and including) said minimum value 1.0 and said maximum value 10.0, i.e., all subranges having a minimum value equal to or greater than 1.0 and a maximum value equal to or less than 10.0, such as, for example, 2.4 to 7.6. Any maximum numerical limit described herein is intended to include all lower numerical limits contained therein, and any minimum numerical limit described 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 describe any subranges contained within the range expressly described herein.

[0044] Referring to two compared elements, features, etc., as “identical” can 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. Additionally, when a parameter is said to be uniform in a given region, it can mean that it is uniform in terms of the mean.

[0045] Throughout this specification, unless otherwise stated, each element may be singular or plural.

[0046] The phrase "any element arranged above (or below)" or "above (or below)" another element can mean that the arbitrary element can be positioned to contact the upper (or lower) surface of the element, and that the other element can be inserted between the element and the arbitrary element disposed on (or below) the element.

[0047] Additionally, it will be understood that when components are referred to as “linked,” “joined,” or “connected” to another component, these components can be directly “linked,” “joined,” or “connected” to each other, or additional components can be “inserted” between these components.

[0048] Throughout this specification, unless otherwise stated, when “A and / or B” is used, it means A, B, or A and B. That is, “and / or” includes any or all combinations of the listed items. When “C to D” is used, unless otherwise stated, it means C or greater and D or less.

[0049] The terminology used in this specification is for describing embodiments of this disclosure and is not intended to limit the scope of this disclosure.

[0050] Figure 1 This is a perspective view showing a secondary battery 100 according to an embodiment of the present disclosure.

[0051] Reference Figure 1 According to embodiments of the present disclosure, a secondary battery 100 may include an electrode assembly 101, a housing 110 that houses the electrode assembly 101 and has an exhaust port formed on at least one side, and an exhaust portion 140 disposed in the exhaust port.

[0052] Electrode assemblies can be formed by winding or stacking a first electrode plate, a diaphragm, and a second electrode plate, which are formed as plates or films. When the electrode assembly is a wound stack, the winding axis can be parallel to the longitudinal direction of the housing 110. In other embodiments, the electrode assembly can be stacked rather than wound, and the shape of the electrode assembly is not limited in this disclosure. Furthermore, the electrode assembly can be a Z-stacked electrode assembly, wherein the positive electrode plate and the negative electrode plate are inserted into both sides of a diaphragm bent into a Z-shape. 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 in the housing 110, and the number of electrode assemblies in the housing 110 is not limited in this disclosure. 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. Of course, the reverse is also possible. Thus, the first electrode plate of the electrode assembly can act as a positive electrode, and the second electrode plate can act as a negative electrode.

[0053] The first electrode plate can be formed by applying a first electrode active material (such as graphite or carbon) to a first electrode substrate formed of a metal foil (such as copper, copper alloy, nickel, or nickel alloy). The first electrode plate may include a first electrode tab (e.g., a first uncoated portion), which is a region where the first electrode active material is not applied. The first electrode tab can serve as a current flow path between the first electrode plate and the first electrode terminal. In some embodiments, the first electrode tab can be formed by pre-cutting it to protrude to one side of the electrode assembly during the manufacture of the first electrode plate, or the first electrode tab can protrude to one side of the electrode assembly more than the diaphragm (e.g., further than or beyond the diaphragm) without being individually cut.

[0054] The second electrode plate can be formed by applying a second electrode active material (such as a transition metal oxide) to a second electrode substrate formed of a metal foil (such as aluminum or an aluminum alloy). The second electrode plate may include a second electrode tab (e.g., a second uncoated portion), which is a region where the second electrode active material is not applied. The second electrode tab can serve as a current flow path between the second electrode plate and the second electrode terminal. In some embodiments, the second electrode tab 114 can be formed by pre-cutting it during the manufacture of the second electrode plate to protrude to the other side (e.g., the opposite side) of the electrode assembly, or the second electrode plate can protrude to the other side of the electrode assembly more than the diaphragm (e.g., further than or beyond the diaphragm) without being separately cut.

[0055] The membrane 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.

[0056] The porous substrate can be a polymer membrane formed from any of the following polymers: polyolefins (such as polyethylene and polypropylene), polyesters (such as polyethylene terephthalate and polybutylene terephthalate), polyacetal, polyamide, polyimide, polycarbonate, polyetherketone, polyaryletherketone, polyetherimide, polyamideimide, polybenzimidazole, polyethersulfone, polyphenylene ether, cyclic olefin copolymers, polyphenylene sulfide, polyethylene naphthalate, glass fiber, Teflon and polytetrafluoroethylene; or copolymers or mixtures of two or more of the above materials.

[0057] Organic materials may include polyvinylidene fluoride polymers or (meth)acrylic acid polymers.

[0058] Inorganic materials may include, but are not limited to, inorganic particles selected from the following: Al2O3, SiO2, TiO2, SnO2, CeO2, MgO, NiO, CaO, GaO, ZnO, ZrO2, Y2O3, SrTiO3, BaTiO3, Mg(OH)2, boehmite and combinations thereof.

[0059] Organic and inorganic materials can be mixed in a coating, or coatings containing organic materials and coatings containing inorganic materials can be stacked.

[0060] Return to reference Figure 1 The casing 110 can form the entire exterior of the secondary battery 100. For example, the secondary battery 100 can be a prismatic battery. In this case, the casing 110 of the secondary battery 100 can have, for example, a generally cuboid shape.

[0061] The housing 110 may include a body 111 and a cover 112. The body 111 may have a cuboid shape with an open end and may define a receiving space for receiving an electrode assembly. For example, the body 111 may include a rectangular bottom surface and four sidewalls extending vertically from the bottom surface. For example, the sidewalls may include two long sides facing each other and two short sides facing each other, such that the housing 110 can be configured as a box shape with an open end. Thus, the electrode assembly can be placed inside the housing 110 so as to be supported by the bottom surface of the housing and surrounded by the four sidewalls.

[0062] The cover plate 112 can be attached to the body 111 to seal the housing 110. For example, the cover plate 112 can be attached to one end of the side wall of the body 111, thereby closing the open end of the body 111.

[0063] The first electrode terminal 120 and the second electrode terminal 130 can be coupled to the cover plate 112. For example, as Figure 1 As shown, the first electrode terminal 120 and the second electrode terminal 130 can be disposed at a certain interval on one (e.g., the same) surface of the cover plate 112. In another example, the positions of the first electrode terminal 120 and the second electrode terminal 130 according to this disclosure can be varied.

[0064] The first electrode terminal 120 and the second electrode terminal 130 can protrude outward through the cover plate 112. For example, the first electrode terminal 120 can be electrically connected to a first electrode in the electrode assembly, and the second electrode terminal 130 can be electrically connected to a second electrode in the electrode assembly. Of course, the reverse arrangement is also possible.

[0065] exist Figure 1 The diagram shows that both the first electrode terminal 120 and the second electrode terminal 130 are attached to the cover plate 112. However, at least one (e.g., only one) of the first electrode terminal 120 or the second electrode terminal 130 may be attached to the cover plate 112.

[0066] At least one side of the housing 110 may include a vent, and a vent portion 140 may be disposed in the vent. The vent portion 140 may be formed in, for example, a cover plate 112. The vent portion 140 may prevent the secondary battery 100 from exploding or prevent a chain thermal reaction in a secondary battery disposed adjacent to the secondary battery 100.

[0067] exist Figure 1 The diagram shows a single exhaust portion 140 formed at the center of the cover plate 112, but the number and location of the exhaust portions 140 can vary. Exhaust portions 140 can be formed in any number at any location on the housing 110. Reference will be made below. Figures 3 to 6 Describe in detail the shape and function of the exhaust port and exhaust section 140.

[0068] The housing 110 may be formed of, for example, stainless steel. The vent portion 140 formed on one side of the housing 110 may be formed of the same stainless steel as the housing 110.

[0069] The cover plate 112 may include an electrolyte inlet 150. For example, the electrolyte inlet 150 may be a through hole formed in the cover plate 112. After the cover plate 112 is engaged to the open end of the housing 110 to seal it, electrolyte can be injected into the interior of the housing 110 through the electrolyte inlet 150. After the electrolyte is injected, the electrolyte inlet 150 can then be sealed with a sealing member.

[0070] exist Figure 1 The diagram shows that both the venting portion 140 and the electrolyte inlet 150 are formed in the cover plate 112, but at least one (e.g., only one) of the venting portion 140 or the electrolyte inlet 150 may be formed in the cover plate 112. Furthermore, the cover plate 112 may be a cover or cap that does not form (e.g., does not include) the venting portion 140 or the electrolyte inlet 150.

[0071] Figure 2 This is a perspective view showing another embodiment of the secondary battery 200 according to the present disclosure. Figure 2 It shows having with Figure 1 Perspective views of secondary batteries 200 in different forms of secondary batteries 100 are shown.

[0072] Reference Figure 2 According to embodiments of the present disclosure, a secondary battery 200 may include an electrode assembly, a housing 210 that houses the electrode assembly and has an exhaust port formed on at least one side, and an exhaust portion 240 disposed in the exhaust port.

[0073] The housing 210 may include a body 211, a first cover plate 212, and a second cover plate. The body 211 may have a cuboid shape, with a first end open and a second end opposite to the first end also open. For example, the body 211 may include opposite long sidewall portions, opposite short sidewall portions, a first open surface, and a second open surface.

[0074] The first cover plate 212 and the second cover plate can be coupled to the body 211 to seal the housing 210. For example, the first cover plate 212 can be coupled to the first open surface (i.e., the first end) of the body 211, and the second cover plate can be coupled to the second open surface (i.e., the second end) of the body 211.

[0075] A first cover plate 212 may be coupled to a first electrode terminal 220, which is electrically connected to a first electrode of the electrode assembly. The first electrode terminal 220 may protrude outward through the first cover plate 212. Similarly, a second cover plate may be coupled to a second electrode terminal, which is electrically connected to a second electrode of the electrode assembly, and the second electrode terminal may protrude outward through the second cover plate. At least one of the first cover plate 212 or the second cover plate may include an electrolyte inlet 250.

[0076] At least one surface of the housing 210 may include an exhaust portion 240. For example... Figure 2 As shown, the exhaust portion 240 can be formed on the main body 211 of the housing 210. For example, as Figure 2 As shown, the exhaust portion 240 can be formed on the upper surface of the housing 210, while the electrolyte injection port 250 and the first electrode terminal 220 can be formed on the side surface of the housing 210 perpendicular to the upper surface.

[0077] The remaining structure of the secondary battery 200 can be referenced. Figure 1 The described structures are the same. Although Figure 1 and Figure 2 An example of a secondary battery that is a prismatic battery or a side-terminal prismatic battery is shown, but the type of secondary battery can vary. For example, the secondary battery can be a cylindrical battery, a pouch battery, or any other type of battery. In this case, an venting portion can be formed on at least one surface of the casing, and the location of the venting portion can vary appropriately depending on the type of casing.

[0078] In the following text, reference will be made to Figures 3 to 6 A detailed description is provided of the venting portion included in a secondary battery according to embodiments of the present disclosure.

[0079] Figure 3 It shows along Figure 1 A cross-sectional view of the secondary battery 100 taken by line a-a'.

[0080] Reference Figure 3 The vent 141 can be configured to penetrate at least one surface of the housing 110. For example, as Figure 3 As shown, at least one side of the housing 110 may include a cover plate 112, and an exhaust portion 140 may be formed in the cover plate 112. However, the position of the exhaust portion 140 formed in the cover plate 112 can vary. In another example, as... Figure 2 As shown, the exhaust portion 140 can also be formed on one side of the main body 111.

[0081] like Figure 3As shown, the vent 141 can be disposed between the first electrode terminal 120 and the second electrode terminal 130 disposed on the cover plate 112. When the vent section 140 breaks, the exhaust material can be discharged through the vent 141, and the exhaust material may include exhaust gas, explosion pressure, flame, and fragments.

[0082] The venting portion 140 can be inserted into the venting port 141 while being coupled to it. Therefore, the venting portion 140 can seal the venting port 141.

[0083] Figure 4 A detailed cross-sectional view of the venting portion 140 of a secondary battery according to an embodiment of the present disclosure is shown. Figure 4 yes Figure 3 An enlarged view of the part within the dashed circle.

[0084] Reference Figure 4 The venting portion 140 in the secondary battery according to embodiments of the present disclosure may include a polymer layer 161 and a brittle layer 163 disposed on the polymer layer 161. The polymer layer 161 may be attached to the brittle layer 163 via an adhesive layer 162.

[0085] The polymer layer 161 can possess chemical and thermal stability, ensuring it does not react with high-temperature gases or electrolytes that may be generated inside the secondary battery, and minimizing chemical changes or damage at high temperatures. Furthermore, the polymer layer 161 can exhibit excellent elasticity, thereby preventing excessive expansion or rupture when the internal pressure of the secondary battery increases.

[0086] According to embodiments of this disclosure, polymer layer 161 may include at least one of polypropylene, polyimide, polyvinyl chloride, polytetrafluoroethylene, polyurethane, polyamide, and combinations thereof.

[0087] The polymer layer 161 can be disposed at the bottom of the venting portion 140 to not only support the brittle layer 163 but also seal the venting hole 141. For example, see reference... Figure 3 and Figure 4 The length of the polymer layer 161 in the longitudinal direction of the body 111 of the housing 110 can be equal to the length of the vent 141, thus the polymer layer 161 can seal the vent 141. For example, refer to... Figure 3 and Figure 4 The polymer layer 161 can directly face (e.g., can directly contact) the interior of the body 111 of the housing 110.

[0088] The polymer layer 161 can have a fracture pressure of less than 5 bar. When no external impact occurs and the internal pressure of the secondary battery increases, the polymer layer 161 can be damaged before the brittle layer 163. Alternatively, if an external impact does occur, the brittle layer 163 can crack first, and the polymer layer 161 can withstand the internal pressure until it reaches its own fracture pressure, at which point the polymer layer 161 can crack.

[0089] The thickness (P1) of polymer layer 161 can be less than 1 mm. If the thickness (P1) of polymer layer 161 is greater than or equal to 1 mm, the fracture pressure can become too high, causing polymer layer 161 to fail to fracture even if brittle layer 163 fractures in an event such as an external impact.

[0090] The brittle layer 163 can be formed of a highly brittle material, thus it can crack under relatively low pressure in the event of a short circuit or external impact, rapidly releasing the heat and high-temperature gases generated inside the secondary battery to the outside and quickly reducing the internal pressure of the secondary battery. This can prevent the secondary battery from exploding or being damaged, and can further prevent heat from spreading to adjacent secondary batteries.

[0091] According to embodiments of this disclosure, the brittle layer 163 may include at least one of glass, ceramic, silicon, limestone, aluminum oxide (Al2O3), indium tin oxide (ITO), magnesium alloy, and combinations thereof.

[0092] The brittle layer 163 can have a fracture pressure of 5 to 20 bar. In other words, it can crack under relatively high pressure when no external impact occurs, preventing moisture from entering the secondary battery and thus ensuring battery life. Simultaneously, in the event of an external impact, the brittle layer 163 cracks first, leaving only the polymer layer 161 with a relatively low fracture pressure. Therefore, the venting section 140 can open under low fracture pressure, rapidly dissipating heat and high-temperature gases from inside the secondary battery.

[0093] When no external impact occurs, the brittle layer 163 can be used as a support, and the thickness of the brittle layer 163 can be varied. For example, refer to... Figure 3 and Figure 4 The brittle layer 163 may be on the polymer layer 161 and may face the exterior of the body 111 of the housing 110. For example, refer to Figure 4 Along the longitudinal direction of the exhaust portion 140 (i.e., the longitudinal direction of the housing 110), the brittle layer 163 may be shorter than the polymer layer 161.

[0094] According to embodiments of the present disclosure, the venting portion 140 may further include an adhesive layer 162 disposed between the polymer layer 161 and the brittle layer 163 (for example, the venting portion 140 may include a stack of the polymer layer 161, the adhesive layer 162 and the brittle layer 163).

[0095] According to embodiments of this disclosure, adhesive layer 162 may include at least one of acrylic adhesives, rubber adhesives, silicone adhesives, epoxy adhesives, polyurethane adhesives, cyanoacrylate adhesives, polyvinyl chloride adhesives, hot melt adhesives, and combinations thereof. For example, the adhesive may include an acrylic adhesive, which may primarily comprise an acrylic polymer and exhibit strong adhesive strength. When the venting portion 140 is formed of a resin material, adhesive layer 162 may be configured to provide a strong adhesive acrylic adhesive on the surface of the resin material. Therefore, if the internal pressure of the secondary battery 100 is lower than the burst pressure of the venting portion 140, the venting portion 140 will not crack or separate from the cover.

[0096] Figure 5 The surface of the casing 110 of a secondary battery according to an embodiment of the present disclosure is shown.

[0097] See Figure 5 In a secondary battery according to an embodiment of the present disclosure, the lower end of one side of the casing 110 that contacts the vent 141 may include a first stepped portion 170 and a second stepped portion 180, the second stepped portion 180 being connected to the first stepped portion 170 and located at a level higher than the upper surface of the first stepped portion 170. For example, referring to... Figures 3 to 5 The lower end of one side of the housing 110 that contacts the vent 141 can refer to the inner surface of the housing 110 facing the interior of the housing 110. For example, refer to Figure 4 and Figure 5 Relative to the interior of housing 110, the second stepped portion 180 may be located at a level higher than the upper surface of the first stepped portion 170 (e.g., above the upper surface of the first stepped portion 170). For example, refer to... Figure 5 The first stepped portion 170 and the second stepped portion 180 can be arranged sequentially from the inner surface of the housing 110 including the vent 141 toward the outer surface of the housing 110 including the vent 141, and the first stepped portion 170 and the second stepped portion 180 can define the side of the vent 141 to accommodate Figure 4 The exhaust section 140.

[0098] For example, an vent 141 may be formed at the center of one side of the housing 110, and one side of the vent 141 may contact the first stepped portion 170 and the second stepped portion 180 (e.g., the same side of the vent 141 may contact both the first stepped portion 170 and the second stepped portion 180). Around the vent 141, each of the first stepped portion 170 and the second stepped portion 180 having the same shape and size may be arranged in a symmetrical position relative to the vent 141 (e.g., when viewed in a top view, each of the first stepped portion 170 and the second stepped portion 180 may surround the entire periphery of the vent 141).

[0099] The first stepped portion 170 may be connected to a lower (e.g., inner) surface of one side of the housing 110 that contacts the vent 141, and may include a first surface 171 perpendicular to the lower surface and a second surface 172 connected to the first surface 171 and parallel to the lower surface. The length (T1) of the second surface 172 along the longitudinal direction of the housing 110 may be greater than or equal to 2 mm. When the length (T1) of the second surface 172 is greater than or equal to 2 mm, the sealing effect of the polymer layer bonded to the first stepped portion 170 on the vent 141 can be improved.

[0100] The second stepped portion 180 may be connected to the second surface 172 and may include a third surface 181 perpendicular to the lower surface and a fourth surface 182 connected to the third surface 181 and parallel to the lower surface. The length (T2) of the fourth surface 182 along the longitudinal direction of the housing 110 may be greater than or equal to 1 mm. When the length (T2) of the fourth surface 182 is greater than or equal to 1 mm, the support function provided by the brittle layer joined to the second stepped portion 180 may be enhanced.

[0101] Figure 6 A surface of the casing 110 of a secondary battery having an exhaust portion 140 according to an embodiment of the present disclosure is shown.

[0102] Reference Figure 6 In the secondary battery according to an embodiment of the present disclosure, the contours of the first stepped portion 170 and the second stepped portion 180 defining the vent 141 can be complementary to the outer contour of the vent portion 140. The vent portion 140 can be fitted into the stepped shape of the vent 141.

[0103] In detail, such as Figures 5 to 6As shown, the polymer layer 161 of the venting portion 140 can be bonded to the first stepped portion 170, and the brittle layer 163 of the venting portion 140 can be bonded to the second stepped portion 180. An adhesive layer 162 may also be included between the polymer layer 161 and the brittle layer 163, imparting adhesion to the two layers, and the adhesive layer 162 may have a length corresponding to the length of the brittle layer 163.

[0104] The polymer layer 161 can be bonded to the first stepped portion 170 such that the first surface 171 contacts the side surface of the polymer layer 161, and the second surface 172 contacts a portion of the upper surface of the polymer layer 161. Therefore, the polymer layer 161 can be stably fixed by the first stepped portion 170.

[0105] The brittle layer 163 can be bonded to the second stepped portion 180 such that the third surface 181 contacts the side surface of the brittle layer 163 and the fourth surface 182 contacts a portion of the upper surface of the brittle layer 163. Therefore, the brittle layer 163 can be stably fixed by the second stepped portion 180.

[0106] In addition to being disposed between the polymer layer 161 and the brittle layer 163, the adhesive layer 162 may also be included between the polymer layer 161 and the first stepped portion 170, and between the brittle layer 163 and the second stepped portion 180. For example, the first surface 171 and the second surface 172 included in the first stepped portion 170, and the third surface 181 and the fourth surface 182 included in the second stepped portion 180, may each have an adhesive layer containing an adhesive component inserted therein, so that the polymer layer 161 and the brittle layer 163 can be stably fixed to one side surface of the housing 110.

[0107] The following will refer to Figures 7 to 11 Details are described regarding the protrusion or groove structure included in the casing of a secondary battery according to embodiments of the present disclosure.

[0108] Figure 7 and Figure 8 The surface of the casing of a secondary battery according to other embodiments of the present disclosure is shown.

[0109] Reference Figure 7 The secondary battery according to embodiments of the present disclosure may include an electrode assembly, a housing 110 housing the electrode assembly and having a vent hole formed on at least one side, and a vent portion 140 disposed in the vent hole. Furthermore, a protrusion structure 191 may be formed at the upper end of the housing 110 in contact with the vent hole, and the vent portion 140 in the vent hole may include a polymer layer 161, an adhesive layer 162 disposed on the polymer layer 161, and a brittle layer 163 disposed on the adhesive layer 162. For example, see reference... Figure 7The protrusion 191 may be integral with the housing 110 and extend from the housing 110 into the vent hole to partially overlap with the edge of the upper surface of the brittle layer 163 (e.g., the brittle layer 163 may be located between the polymer layer 161 and the protrusion 191).

[0110] The protrusion 191 can be formed by extending a portion of the upper end of one side of the housing 110 that contacts the vent hole along the direction of the vent hole parallel to the lower surface of that side of the housing 110. For example, the protrusion 191 can be formed at a portion of the upper end of one side of the housing 110 that contacts the vent hole, and another protrusion 191 of the same shape and size can be formed symmetrically about the vent hole at the opposite portion of the upper end of the housing 110.

[0111] When an external impact occurs, the protrusion 191 can facilitate the failure of the brittle layer 163. That is, when an external impact occurs, increasing the temperature and pressure inside the secondary battery, the brittle layer 163 can deform beyond the top of the vent hole due to the internal pressure of the battery. By contacting the protrusion 191 in this deformed state, the brittle layer 163 can be more easily damaged than if it were simply broken by the internal pressure of the battery.

[0112] The length (T3) of the protrusion 191 along the longitudinal direction of the housing 110 can be from 1 mm to 10 mm. Within this range, the protrusion 191 can easily break the brittle layer 163 and can achieve excellent heat and gas discharge function when the exhaust section 140 is opened.

[0113] Reference Figure 8 The secondary battery according to embodiments of the present disclosure may include an electrode assembly, a housing housing the electrode assembly and having an vent hole formed on at least one side, and an vent portion 140 disposed in the vent hole. Furthermore, a groove structure 192 may be formed at the upper end of the housing 110 that contacts (e.g., is in fluid communication with) the vent hole, and the vent portion 140 in the vent hole may include a polymer layer 161, an adhesive layer 162 disposed on the polymer layer 161, and a brittle layer 163 disposed on the adhesive layer 162. For example, refer to… Figure 8 The groove structure 192 may surround the top of the vent (e.g., a portion of the housing 110 may be between the groove structure 192 and the upper surface of the edge of the polymer layer 161).

[0114] The groove structure 192 can be formed by indenting a portion of the upper end of one side of the housing 110 that contacts the vent. For example, the groove structure 192 can be formed at a portion of the upper end of one side of the housing 110 that contacts the vent, and another groove structure 192 of the same shape and size can be formed symmetrically about the vent at the opposite portion of the upper end of the housing 110.

[0115] When an external impact occurs, the groove structure 192 can facilitate the breakage of the brittle layer 163. That is, if the internal temperature and pressure of the secondary battery increase due to an external impact, the brittle layer 163 can deform beyond the top edge of the vent hole under internal pressure. At this time, when the deformed brittle layer 163 comes into contact with the groove structure 192, the deformed brittle layer 163 can be more easily broken than simply cracking due to the internal pressure of the secondary battery.

[0116] The length (T4) of the groove structure 192 along the longitudinal direction of the housing 110 can be from 1 mm to 10 mm. Within this range, the groove structure 192 can more easily break the brittle layer 163 and can exhibit excellent heat and gas discharge function when the exhaust section 140 is open.

[0117] Figures 9 to 11 This is a top view showing the surface of the casing 110 of a secondary battery according to other embodiments of the present disclosure. Specifically, Figures 9 to 11 Examples of various shapes of the protrusion structure 191 formed on the housing 110 are shown.

[0118] Reference Figures 9 to 11 The brittle layer 163 may have a shape corresponding to the formation of the vent hole, and the protrusion structure 191 may be formed at any location along the portion where the brittle layer 163 contacts the housing 110.

[0119] The raised structure 191 can be formed symmetrically or asymmetrically about the center of the vent hole. Additionally, to facilitate the cracking of the brittle layer 163, two or more raised structures 191 can be formed. For example, see reference... Figure 9 Two protruding structures 191 can be formed symmetrically about the center of the vent in the direction of the short side of the housing 110. (Refer to...) Figure 10 Two protruding structures 191 can be formed symmetrically about the center of the vent hole along the long side of the housing 110. (Refer to...) Figure 11 Two or more protrusions 191 may be formed symmetrically about the center of the exhaust hole at the long side portion and the curved portion of the exhaust hole.

[0120] At the same time, refer to again Figure 7 and Figure 8According to embodiments of the present disclosure, the lower end of one side of the housing 110 that contacts the vent may include a stepped portion. Furthermore, according to embodiments of the present disclosure, a polymer layer 161 may be bonded to the stepped portion. The shape of the stepped portion may be similar to that described above. Figure 5 The first step portion is the same as described, and the bonding between the polymer layer 161 and the step portion can be as shown in the reference. Figure 6 As explained.

[0121] According to embodiments of this disclosure, the brittle layer 163 may be bonded (e.g., in a cross-sectional view) to two (e.g., facing) inner surfaces on one side of the housing 110 that contact the vent. In other words, the two (e.g., opposite) side surfaces of the brittle layer 163 may contact two (e.g., facing) inner surfaces of the housing 110 that have the protrusion structure 191 or the groove structure 192 formed thereon. In this case, the brittle layer 163 may not contribute to sealing the vent.

[0122] exist Figures 7 to 11 In the case of a secondary battery, including a casing with raised or recessed structures, the remaining construction can be the same as described above. Figures 1 to 6 The descriptions are identical in structure.

[0123] In summary, secondary batteries can include venting sections that can release heat and gases in the event of internal short circuits, overcurrent or overvoltage charging conditions, exposure to high temperatures, or external impacts. Some known types of venting sections are formed of flexible metallic materials and are characterized by opening only when a certain internal pressure is reached. However, if the rupture pressure of the venting section is too low, moisture and other gases can penetrate into the battery cells and shorten their lifespan, while if the rupture pressure is too high, there may be a problem in the rapid release of heat and gases in the event of an event such as a short circuit.

[0124] Conversely, according to some embodiments of this disclosure, by placing the venting portion, comprising a polymer layer and a brittle layer, on one surface of the secondary battery casing, the burst pressure can be reduced in the event of an event such as an external impact. Therefore, when such an event occurs, heat and gases inside the secondary battery can be rapidly released, and a high burst pressure can be achieved to ensure the lifespan of the secondary battery when no event such as an external impact occurs. Specifically, when an event occurs, the brittle layer can crack first and open the venting portion, thereby preventing heat propagation to adjacent battery cells and subsequent thermal runaway.

[0125] In addition, according to some embodiments of this disclosure, by forming a protruding structure or a groove structure at the upper end of the housing that contacts the vent hole, the brittle layer can be more easily damaged under external impact or the like.

[0126] However, 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 above detailed description other aspects and features not mentioned.

[0127] Although this disclosure has been described above with respect to certain embodiments, this disclosure is not limited to these embodiments. Various modifications and variations can be made by those skilled in the art without departing from the spirit of this disclosure or the scope of the appended claims.

[0128] Example embodiments have been disclosed herein, and although specific terminology has been used, it is used and interpreted in a general and descriptive sense only and not for limiting purposes. In some instances, as will be apparent to those skilled in the art at the time of filing this application, unless otherwise specifically indicated, 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 of the invention as set forth in the following claims.

Claims

1. A secondary battery, comprising: Electrode assembly; A housing that houses the electrode assembly, the housing having an vent on at least one side; as well as The exhaust portion in the exhaust port includes a polymer layer and a brittle layer on the polymer layer.

2. The secondary battery according to claim 1, wherein the polymer layer comprises at least one of polypropylene, polyimide, polyvinyl chloride, polytetrafluoroethylene, polyurethane, polyamide, and combinations thereof.

3. The secondary battery according to claim 1, wherein the brittle layer comprises at least one of glass, ceramic, silicon, limestone, aluminum oxide, indium tin oxide, magnesium alloy, and combinations thereof.

4. The secondary battery according to claim 1, wherein the lower end of at least one side of the housing contacts the vent, the lower end comprising: First step section; as well as The second step portion is connected to the first step portion, and the second step portion is at a level higher than the upper surface of the first step portion.

5. The secondary battery of claim 4, wherein the polymer layer is bonded to the first stepped portion.

6. The secondary battery of claim 4, wherein the brittle layer is bonded to the second stepped portion.

7. The secondary battery according to claim 4, wherein the first stepped portion comprises: A first surface, connected to the lower surface of the housing that contacts the vent hole on at least one side, the first surface being perpendicular to the lower surface; as well as A second surface is connected to the first surface, the second surface is parallel to the lower surface, and the length of the second surface along the longitudinal direction of the housing is greater than or equal to 2 mm.

8. The secondary battery according to claim 7, wherein the second stepped portion comprises: A third surface connected to the second surface, the third surface being perpendicular to the lower surface; as well as A fourth surface, connected to the third surface, is parallel to the lower surface, and has a length greater than or equal to 1 mm along the longitudinal direction of the housing.

9. The secondary battery according to claim 1, wherein at least one side of the housing includes a cover plate, and the venting portion is in the cover plate.

10. The secondary battery according to claim 1, further comprising an adhesive layer between the polymer layer and the brittle layer.

11. The secondary battery of claim 10, wherein the adhesive layer comprises at least one of acrylic adhesive, rubber adhesive, silicone adhesive, epoxy adhesive, polyurethane adhesive, cyanoacrylate adhesive, polyvinyl chloride adhesive, hot melt adhesive, and combinations thereof.

12. The secondary battery according to claim 1, wherein the thickness of the polymer layer is less than 1 mm.

13. A secondary battery, comprising: Electrode assembly; A housing that houses the electrode assembly, the housing having an vent on at least one side; as well as The exhaust portion in the exhaust port includes a polymer layer, an adhesive layer on the polymer layer, and a brittle layer on the adhesive layer. The upper end of at least one side of the housing that contacts the vent hole includes a protruding structure or a groove structure.

14. The secondary battery according to claim 13, wherein: The upper end of the housing that contacts the vent includes the protruding structure, and The protruding structure is integrally formed with the upper end of at least one side of the housing that contacts the vent hole, and the protruding structure extends parallel to the lower surface of at least one side of the housing toward the vent hole.

15. The secondary battery according to claim 14, wherein the length of the protrusion structure along the longitudinal direction of the housing is 1 mm to 10 mm.

16. The secondary battery according to claim 13, wherein: The upper end of the housing that contacts the vent hole includes the groove structure, and The groove structure is recessed inward into the upper end of at least one side of the housing that contacts the vent hole.

17. The secondary battery according to claim 16, wherein the length of the groove structure along the longitudinal direction of the housing is 1 mm to 10 mm.

18. The secondary battery of claim 13, wherein the lower end of the at least one side of the housing that contacts the vent hole includes a stepped portion.

19. The secondary battery of claim 18, wherein the polymer layer is bonded to the stepped portion.

20. The secondary battery of claim 13, wherein the brittle layer is bonded to the inner surface of at least one side of the housing that is in contact with the vent hole.

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