Secondary battery

Abstract

The present invention relates to a secondary battery capable of preventing deformation of a case and a cover plate due to a gas by reducing the gas inside the case by adsorbing the gas through an adsorbent accommodated inside a gas adsorption structure when the gas inside the case increases to increase an internal pressure. In an example, disclosed is a secondary battery including: an electrode assembly including a first electrode plate and a second electrode plate; a case accommodating the electrode assembly therein and having one end opening; the cover plate is used for sealing one end opening of the shell; and a gas adsorption structure mounted on a lower surface of the cover plate and containing a gas adsorbent, where the gas adsorbent may be surrounded by an inner membrane, and the inner membrane may be surrounded by an outer membrane and a frame.

Description

Technical Field

[0001] This invention relates to a secondary battery. Background Technology

[0002] Unlike primary batteries, which are non-rechargeable, secondary batteries are rechargeable and re-dischargeable. Low-capacity secondary batteries can be used in various portable small electronic devices such as smartphones, feature phones, laptops, digital cameras, or camcorders, while high-capacity secondary batteries are widely used as power sources for motor drives, such as those in hybrid or electric vehicles. A secondary battery may include an electrode assembly containing positive and negative electrodes, a housing for the electrode assembly, and electrode terminals connected to the electrode assembly.

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

[0004] Technical issues When the gas inside the shell increases and the internal pressure increases, the present invention can prevent the shell and cover plate from deforming due to the gas by adsorbing the gas through the adsorbent contained inside the gas adsorption structure, thereby reducing the gas inside the shell.

[0005] In addition, the present invention can extend the life of the secondary battery by delaying the operation of the safety vent due to the gas adsorption structure.

[0006] However, the technical problems to be solved in the disclosed embodiments are not limited to those described above, and those skilled in the art will clearly understand from the following description other technical problems not mentioned herein.

[0007] Technical solution A secondary battery according to an embodiment of the present invention for solving a technical problem may include: an electrode assembly including a first electrode plate and a second electrode plate; a housing containing the electrode assembly and having an end opening; a cover plate sealing an end opening of the housing; and a gas adsorption structure mounted on the lower surface of the cover plate and containing a gas adsorbent, wherein the gas adsorbent may be surrounded by an inner membrane, and the inner membrane may be surrounded by an outer membrane and a frame.

[0008] The frame may have an interior space consisting of an upper plate fixed to a cover plate and sidewalls extending from the edge of the upper plate toward the electrode assembly.

[0009] The outer membrane can be attached to the end of the sidewall to seal the interior of the frame.

[0010] The frame may also include a central structure, which is installed across the side walls and divides the interior space of the frame into an upper and lower region.

[0011] The central structure may have holes or openings to allow connection between the upper and lower regions.

[0012] An inner membrane containing a gas adsorbent can be housed in the upper region, which is the upper side of the central structure in the frame.

[0013] The central structure can be set horizontally relative to the upper plate.

[0014] The secondary battery may also include a tip, which is mounted on the underside of the central structure and has a pointed tip facing the outer membrane.

[0015] In terms of the plane, the tip can be positioned at the center of the central structure.

[0016] The height of the tip can be less than the distance from the central structure to the outer membrane.

[0017] When the internal pressure of the shell increases, the outer membrane can become concave and deformed into the frame, thus being damaged by the sharp point.

[0018] The tip is not susceptible to corrosion due to gases generated inside the casing and can be made of rigid ceramic or plastic materials.

[0019] The outer membrane and the central structure can be arranged horizontally relative to each other.

[0020] The side walls of the frame can be of equal height.

[0021] The inner membrane allows gas to pass through but blocks liquids.

[0022] The outer membrane can be a membrane that blocks gases and liquids.

[0023] The inner membrane can be a non-woven filter membrane or a breathable membrane with micropores that can block liquids.

[0024] Gas adsorbents may include at least one of calcium carbonate, potassium carbonate, and sodium hydroxide.

[0025] The outer membrane can be flat.

[0026] The outer membrane can be polyethylene, polypropylene, or a composite membrane of polyethylene and polypropylene.

[0027] Beneficial effects According to the present invention, a secondary battery can be provided that, when the gas inside the casing increases and the internal pressure increases, the secondary battery can reduce the gas inside the casing by adsorbing the gas through an adsorbent contained inside the gas adsorption structure, thereby preventing the casing and cover plate from deforming due to the gas.

[0028] According to the present invention, the life of a secondary battery can be extended by delaying the operation of the safety vent due to the gas adsorption structure.

[0029] According to another aspect of the invention, a battery pack manufactured using a battery with an improved structure and a vehicle including the battery pack can be provided.

[0030] However, the aspects of this disclosure are not limited to those described above, and those skilled in the art will clearly understand from the detailed description below that other aspects are not mentioned. Attached Figure Description

[0031] The accompanying drawings, which illustrate preferred embodiments of the present disclosure, are used together with the detailed description of the present disclosure to further understand the technical concept of the present disclosure. Therefore, the present disclosure should not be construed as being limited to the contents described in these drawings.

[0032] Figure 1 This is a perspective view showing a secondary battery according to the present invention.

[0033] Figure 2 It is along Figure 1 The sectional view taken from line 2-2'.

[0034] Figure 3 It is shown Figure 2 An enlarged cross-sectional view of the gas adsorption structure in a secondary battery.

[0035] Figure 4 It is shown Figure 3 A cross-sectional view of the gas adsorption structure after operation.

[0036] Figure 5A and Figure 5B This is a perspective view showing a battery pack including an exemplary secondary battery according to the present invention.

[0037] Figure 6A and Figure 6B These are perspective and side views illustrating a vehicle including an exemplary battery pack according to the present invention. Detailed Implementation

[0038] The present disclosure will be described in detail below. Before giving the following detailed description of the present disclosure, it should be noted that the terms and words used in the specification and claims should not be construed as limited to their ordinary meaning or dictionary definitions, but should be interpreted on the basis of the concepts which the inventors may appropriately define in order to best describe the disclosure, in a meaning and concept consistent with the technical concept of the present disclosure. Therefore, the embodiments described in the specification and the constructions described in the drawings are merely the most preferred embodiments of the invention and do not represent the entirety of the technical ideas of the invention. It will be understood that various equivalents and modifications may exist instead of them at the time of filing this application.

[0039] It will also be understood that when the terms “comprising,” “including,” and / or variations thereof are used in this specification, it indicates the presence of the stated features, quantities, steps, operations, elements, and / or components, but does not preclude the presence or addition of one or more other features, quantities, steps, operations, elements, components, and / or groups thereof.

[0040] Furthermore, for better understanding of the invention, the drawings are not to scale, and the dimensions of some components may be exaggerated. Additionally, the same reference numerals may be assigned to the same components in different embodiments.

[0041] The comparison of two objects as identical implies that they are substantially the same. Therefore, the phrase "substantially the same" can include situations where similarity is considered low in the relevant art, such as a deviation within 5%. Additionally, when any parameter is stated to be uniform over a given region, this can mean that the parameter is uniform from an average perspective.

[0042] It will be understood that while the terms “first,” “second,” “third,” etc., may be used herein to describe various elements, components, regions, layers, and / or parts, these elements, components, regions, layers, and / or parts should not be limited by these terms. These terms are used to distinguish one element, component, region, layer, or part from another. Therefore, unless otherwise defined, the first element, first component, first region, first layer, or first part described below may be designated as a second element, second component, second region, second layer, or second part.

[0043] Throughout this specification, unless the context clearly indicates otherwise, the singular forms “one” and “a (species / being)” are intended to include the plural forms as well.

[0044] The arrangement of any component "above (or below)" or "on (or below)" a component means that any component is positioned to contact the upper (or lower) surface of the component. Additionally, it can mean that other components can be positioned between the component and any components disposed on (or below) the component.

[0045] Furthermore, it will be understood that when elements are referred to as being "on" another element, "connected to" or "joined to" another element, these elements may be directly connected to or joined to each other, there may be another intermediary element between them, or the corresponding elements may be connected, joined to or linked to each other through another element.

[0046] Throughout this specification, unless otherwise defined, the expression “A and / or B” means A, B, or A and B, and unless otherwise defined, the expression “C to D” means C or greater and D or less.

[0047] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the invention.

[0048] Figure 1 This is a perspective view showing a secondary battery according to the present invention. Figure 2 It is along Figure 1 The sectional view taken from line 2-2'.

[0049] The secondary battery 100 according to the present invention includes an electrode assembly 110, a first current collector 120, a second current collector 130, a first terminal 140, a second terminal 150, a housing 160, a cover assembly 170, and a gas adsorption structure 180. The secondary battery 100 of the present invention may be referred to as a prismatic secondary battery or a battery.

[0050] Electrode assembly 110 can be formed by laminating or winding a first electrode plate, a diaphragm, and a second electrode plate into a sheet or film shape. Here, the first electrode plate may have a first polarity, for example, it may operate as a positive electrode, and the second electrode plate may have a second polarity, for example, it may operate as a negative electrode. In some examples, electrode assembly 110 may have an electrode core structure in which the first electrode plate, the diaphragm, and the second electrode plate are laminated and then wound.

[0051] The first electrode plate is formed by applying a first electrode active material, such as a transition metal oxide, to a first electrode current collector formed of a metal foil, such as aluminum, and includes an uncoated portion 111 of the first electrode, which is a region where the first active material is not applied. The uncoated portion 111 of the first electrode provides a path for current flow between the first electrode plate and the outside. The uncoated portion 111 of the first electrode is formed to protrude from one side of the electrode assembly 110. In some cases, multiple uncoated portions of the first electrodes may be welded together to form a first current collector terminal block. The uncoated portion 111 of the first electrode protrudes toward one side of the electrode assembly 110.

[0052] The second electrode plate is formed by applying a second electrode active material, such as graphite or carbon, to a second electrode current collector formed of a metal foil, such as copper or nickel, and includes an uncoated portion 112 of the second electrode, which is a region where the second active material is not applied. Furthermore, the uncoated portion 112 of the second electrode is formed to protrude from the other side of the electrode assembly 110. In some cases, multiple uncoated portions of the second electrodes can be welded together to form a second current collector terminal block.

[0053] A separator is positioned between the first and second electrode plates to prevent short circuits and allow lithium ions to move. The separator can be made of polyethylene, polypropylene, or a composite membrane of polyethylene and polypropylene. However, the material of the separator does not limit the scope of the invention.

[0054] Furthermore, after multiple electrode plates (first electrode plate and second electrode plate) are stacked or wound together, the shape of the electrode assembly 110 can be maintained by a separate insulating tape attached to a portion of the outer surface. Subsequently, the insulating tape allows the uncoated portions 111, 112 of the electrode assembly 110 to be welded to the current collectors 120, 130 at precise locations and can be secured, thus maintaining the structure of the electrode assembly 110 even within the final structure of the secondary battery 100.

[0055] Additionally, the electrode assembly 110 is housed together with the electrolyte in the housing 160. The electrolyte may be composed of lithium salts (such as LiPF6, LiBF4) in organic solvents (such as EC (ethylene carbonate), PC (propylene carbonate), DEC (diethyl carbonate), EMC (ethyl methyl carbonate), or DMC (dimethyl carbonate)). Furthermore, the electrolyte may be in a liquid phase, a solid phase, or a gel phase.

[0056] In some examples, compounds capable of reversibly inserting and deintercalating lithium (lithiation intercalation compounds) can be used as the positive electrode active material. Specifically, at least one composite oxide of lithium with a metal selected from cobalt, manganese, nickel, and combinations thereof can be used. The composite oxide can be a lithium transition metal composite oxide, and specific examples include lithium nickel oxides, lithium cobalt oxides, lithium manganese oxides, lithium iron phosphate compounds, cobalt-free nickel manganese oxides, or combinations thereof.

[0057] As an example, a compound represented by any of the following chemical 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 O4-c D c (0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.05); Li a Ni 1-b-c Co 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 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 L1 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).

[0058] In the chemical formula: A is Ni, Co, Mn or a combination thereof; X is Al, Ni, Co, Mn, Cr, Fe, Mg, Sr, V, rare earth elements or a combination thereof; D is O, F, S, P or a combination thereof; G is Al, Cr, Mn, Fe, Mg, La, Ce, Sr, V or a combination thereof; and L1 is Mn, Al or a combination thereof.

[0059] The positive electrode for a lithium secondary battery may include a current collector (e.g., a first substrate) and a positive electrode active material layer formed on the current collector. The positive electrode active material layer includes a positive electrode active material and may also include a binder and / or a conductive material.

[0060] With respect to 100 wt% of the positive electrode active material layer, the content of the positive electrode active material may be 90 wt% to 99.5 wt%, and with respect to 100 wt% of the positive electrode active material layer, the contents of the binder and the conductive material may be 0.5 wt% to 5 wt% respectively.

[0061] As the current collector, aluminum may be used, but is not limited thereto.

[0062] The negative electrode active material includes a material capable of reversibly intercalating / deintercalating lithium ions, lithium metal, an alloy of lithium metal, a material capable of doping and dedoping lithium, or a transition metal oxide.

[0063] The material capable of reversibly intercalating / deintercalating lithium ions may include a carbon-based negative electrode active material, and the carbon-based negative electrode active material 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 or hard carbon, mesophase pitch carbide, calcined coke, etc.

[0064] As the material capable of doping and dedoping lithium, a Si-based negative electrode active material or a Sn-based negative electrode active material may be used. The Si-based negative electrode active material may be silicon, a silicon-carbon composite, SiO x (0 < x < 2), a Si-based alloy, or a combination thereof.

[0065] 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 an amorphous carbon coating on the surface of the silicon particles.

[0066] The silicon-carbon composite may also include crystalline carbon. For example, the silicon-carbon composite may include a core containing crystalline carbon and silicon particles and an amorphous carbon coating layer positioned on the surface of the core.

[0067] The negative electrode for a lithium secondary battery may include a current collector (e.g., a second substrate) and a negative electrode active material layer formed on the current collector. The negative electrode active material layer includes a negative electrode active material and may also include a binder and / or a conductive material.

[0068] For example, the negative electrode active material layer may include 90 wt% to 99 wt% of the negative electrode active material, 0.5 wt% to 5 wt% of the binder, and 0 wt% to 5 wt% of the conductive material.

[0069] As a binder, non-aqueous binders, aqueous binders, dry binders, or combinations thereof can be used. When an aqueous binder is used as a negative electrode binder, it may also include cellulose compounds capable of imparting viscosity.

[0070] As a current collector, any one selected from copper foil, nickel foil, stainless steel foil, titanium foil, nickel foam, copper foam, polymer substrate coated with conductive metal, and combinations thereof can be used.

[0071] Electrolytes used in lithium secondary batteries may include non-aqueous organic solvents and lithium salts.

[0072] Non-aqueous organic solvents act as the medium through which ions involved in the electrochemical reactions of a battery can move.

[0073] Non-aqueous organic solvents can be carbonate solvents, ester solvents, ether solvents, ketone solvents or alcohol solvents, aprotic solvents or combinations thereof, and can be used alone or in combination of two or more.

[0074] In addition, when using carbonate solvents, cyclic carbonates and chain carbonates can be used in combination.

[0075] As described above, a lithium secondary battery can have a separator between the positive and negative electrodes. The separator can be made of polyethylene, polypropylene, polyvinylidene fluoride, or a multilayer film of two or more layers thereof.

[0076] The membrane may include a porous substrate and a coating layer positioned on one or both sides of the porous substrate, the coating layer including organic materials, inorganic materials, or combinations thereof.

[0077] Organic materials may include polyvinylidene fluoride polymers or (meth)acrylic acid polymers.

[0078] Inorganic materials may include inorganic particles selected from, but not limited to, Al2O3, SiO2, TiO2, SnO2, CeO2, MgO, NiO, CaO, GaO, ZnO, ZrO2, Y2O3, SrTiO3, BaTiO3, Mg(OH)2, boehmite, and combinations thereof.

[0079] Organic and inorganic materials can be mixed and exist in a single coating layer, or a coating layer containing organic materials and a coating layer containing inorganic materials can exist in a laminated form.

[0080] The first current collector 120 is formed of a conductive material such as aluminum and is electrically connected to the first electrode plate by bonding to an uncoated portion 111 of the first electrode protruding from one end of the electrode assembly 110. The first current collector 120 can be electrically connected to the uncoated portion 111 of the first electrode by soldering. The first current collector 120 may include a first electrode connection portion 121 extending vertically along one side of the electrode assembly 110 and a first terminal connection portion 122 disposed between the electrode assembly 110 and the cover assembly 170 and bonded to the first terminal 140.

[0081] The first electrode connection portion 121 extends vertically along one side of the electrode assembly 110 and may have an approximately plate-like shape. The first electrode connection portion 121 may be welded together while in contact with the uncoated portion 111 of the first electrode of the electrode assembly 110, and may have the same first polarity as the uncoated portion 111 of the first electrode. For ease of explanation, in the following description, the surface of the first electrode connection portion 121 opposite to one side of the electrode assembly 110 will be referred to as the inner surface, and the surface opposite to one side of the housing 160 will be referred to as the outer surface.

[0082] The first terminal connection portion 122 can be bent from the top end of the first electrode connection portion 121 and can be placed between the cover assembly 170 and the electrode assembly 110. The first terminal connection portion 122 can be integral with the first electrode connection portion 121, or it can be welded and combined to the top end of the first electrode connection portion 121.

[0083] The second current collector 130 is formed of a conductive material such as nickel and is electrically connected to the second electrode plate by contacting the uncoated portion 112 of the second electrode protruding from the other end of the electrode assembly 110. The second current collector 130 may include a second electrode connection portion 131 and a second terminal connection portion 132. The shape of the second current collector 130 is the same as that of the first current collector 120, so repeated descriptions will be omitted.

[0084] The first terminal 140 is formed of a conductive material such as aluminum and is electrically connected to the first current collector 120. The first terminal 140 includes a first terminal post 141 and a first terminal plate 142.

[0085] The first terminal post 141 may protrude upward and extend through the cover plate 171 of the cover assembly 170 by a predetermined length, and may be electrically connected to the first current collector 120 at the lower part of the cover plate 171. Alternatively, in some examples, the first terminal post 141 may protrude upward and extend through the cover plate 171 by a predetermined length. The lower part of the first terminal post 141 may be inserted into a hole provided in the first terminal connection portion 122 of the first current collector 120, and then riveted and / or welded.

[0086] The first terminal plate 142 has a hole, and the upper portion of the first terminal post 141 can be engaged with the hole and riveted and / or welded. The first terminal plate 142 can be positioned on top of the cover plate 171. In some examples, the interface between the exposed upper portion of the first terminal post 141 and the first terminal plate 142 can be welded to each other. For example, by providing a laser beam to the boundary region of the upwardly exposed first terminal post 141 and the first terminal plate 142, the boundary region can be melted and then cooled for welding. In some examples, the first terminal post 141 and the first terminal plate 142 can be electrically insulated from the cover plate 171.

[0087] The second terminal 150 is formed of a conductive material such as nickel and is electrically connected to the second current collector 130. The second terminal 150 includes a second terminal post 151 and a second terminal plate 152. The shape of the second terminal 150 is the same as that of the first terminal 140, so repeated descriptions will be omitted.

[0088] The housing 160 is formed of a conductive metal such as aluminum, aluminum alloy, or nickel-plated steel, and is shaped as a generally hexahedral shape with an opening through which the electrode assembly 110, the first current collector 120, and the second current collector 130 can be inserted and positioned. A cover plate 171 can be coupled to the opening of the housing 160 to seal the housing 160. The inner surface of the housing 160 is substantially insulated to prevent internal short circuits.

[0089] The cover assembly 170 can be coupled to an opening in the housing 160. The cover assembly 170 may include a cover plate 171, a sealing gasket 172, a plug 173, a safety vent 174, an upper insulating member 175, a lower insulating member 176, and a cooling terminal. The cover plate 171 seals the opening in the housing 160. The sealing gasket 172 is made of insulating material and is respectively disposed between the cover plate 171 and a first terminal post 141 of a first terminal 140 and between the cover plate 171 and a second terminal post 151 of a second terminal 150, to seal the portion of each of the first and second terminal posts 141 between the cover plate 171 and the second terminal post 151. The sealing gasket 172 prevents external moisture from penetrating into the interior of the secondary battery 100 or prevents electrolyte contained within the secondary battery 100 from leaking to the outside.

[0090] The plug 173 seals the electrolyte inlet of the cover plate 171, and the safety vent 174 is installed in the vent of the cover plate 171 and may be provided with a notch to open under a set pressure.

[0091] The upper insulating member 175 can be disposed on the upper side of the cover plate 171 between the first terminal plate 142 and the cover plate 171, and between the second terminal plate 152 and the cover plate 171. Furthermore, the upper insulating member 175 is in close contact with the cover plate 171. Additionally, the upper insulating member 175 can also be in close contact with the sealing gasket 172. The upper insulating member 175 can insulate the first terminal plate 142 and the cover plate 171 from each other, and can also insulate the second terminal plate 152 and the cover plate 171 from each other. In some examples, the first terminal post 141 formed on the upper insulating member 175 can electrically connect the first terminal plate 142 and the cover plate 171, so the cover plate 171 can have the same polarity as the first terminal 140. In this case, the housing 160 can also have the same polarity as the cover plate 171, and by insulating the inside of the housing 160, short circuits with the electrode assembly 110 are prevented.

[0092] The lower insulating member 176 can be disposed between the cover plate 171 and the first current collector 120, and between the cover plate 171 and the second current collector 130. The lower insulating member 176 can also be in close contact with the sealing gasket 172. The lower insulating member 176 can also be placed between the first terminal connection portion 122 of the first current collector 120 and the electrode assembly 110, and between the second terminal connection portion 132 of the second current collector 130 and the electrode assembly 110.

[0093] The lower insulating member 176 may be made of insulating material and may prevent electrical contact between the cover plate 171 and the first current collector 120 and between the cover plate 171 and the second current collector 130. In addition, the lower insulating member 176 may prevent electrical contact between the electrode assembly 110 and the first current collector 120 and between the electrode assembly 110 and the second current collector 130.

[0094] The gas adsorption structure 180 can be fixed to the inner surface of the cover plate 171. The gas adsorption structure 180 can be separated from the upper surface of the electrode assembly 110. The gas adsorption structure 180 can be a structure having a gas adsorbent contained therein for adsorbing gases generated inside the electrode assembly. The gas adsorption structure 180 can be installed to be separated from the electrolyte inlet and safety vent 174 of the cover plate 171. Here, the gas adsorption structure 180 is shown mounted on the cover plate 171, but it can be mounted inside the housing 160 without affecting the capacity change of the electrode assembly 110. However, the secondary battery 100 has a gap space provided between the cover plate 171 and the electrode assembly 110 (which occurs when the current collector and terminals are attached to the cover plate 171) to prevent a reduction in the capacity of the electrode assembly 110 when the gas adsorption structure 180 is attached.

[0095] However, the invention is not limited to what is listed herein, and the housing can be constructed in various shapes such as circular or bag-shaped. Furthermore, the housing can be constructed from metals such as aluminum, aluminum alloys, nickel-plated steel, or from a laminated film or plastic forming the bag.

[0096] Figure 3 It is shown Figure 2 A magnified cross-sectional view of the gas adsorption structure in a secondary battery at 180°. Figure 4 It is shown Figure 3 A cross-sectional view of the gas adsorption structure 180 after operation.

[0097] The gas adsorption structure 180 may include a frame 181, an inner membrane 182, a tip 183, and an outer membrane 184. The frame 181 has an internal space and an open side. The gas adsorbent 182a is contained in the inner membrane 182 and the inner membrane 182 is mounted within the frame 181. The tip 183 is fixed within the frame 181 to the opposite side of the inner membrane 182. The outer membrane 184 is joined to the open side of the frame 181. The frame 181 may be made of a plastic material that does not react with the electrolyte.

[0098] The gas adsorption structure 180 is structured such that the gas adsorbent 182a is surrounded by an inner membrane 182, and the outer side of the inner membrane 182 can also be surrounded by a frame 181 and an outer membrane 184.

[0099] Frame 181 may include an upper plate 181a fixed to cover plate 171 and sidewalls 181b extending from the edge of upper plate 181a toward electrode assembly 110. Upper plate 181a may have an upper surface fixed to the inner surface of cover plate 171 by an adhesive or tape. The inner surface of cover plate 171 may be the surface facing electrode assembly 110. The shape of upper plate 181a may vary, including, for example, a circular or polygonal shape. Additionally, sidewalls 181b may have the same height and provide space within frame 181 through upper plate 181a and sidewalls 181b. Frame 181 may also include a central structure 181c mounted across the sidewalls 181b. Central structure 181c may be downwardly spaced from upper plate 181a. Furthermore, central structure 181c may be arranged horizontally relative to upper plate 181a (or central structure 181c may be arranged to remain horizontal with upper plate 181a). The frame 181 can be integrally formed via the upper plate 181a, side walls 181b and central structure 181c.

[0100] Here, the central structure 181c may have a strip shape or a plate shape, but the invention is not limited thereto. However, while the central structure 181c is structurally divided into upper and lower parts, it may have opening regions in at least some areas. For example, the central structure 181c may have holes or opening regions in at least some areas, such that the upper and lower regions can be connected to each other within the interior space of the frame 181.

[0101] The inner membrane 182 can be housed between the upper plate 181a of the frame 181 and the central structure 181c. The central structure 181c can be a device for fixing the inner membrane 182 within the frame 181. A gas adsorbent can be housed within the inner membrane 182. The gas adsorbent may include at least one of calcium carbonate, potassium carbonate, and sodium hydroxide. Additionally, the inner membrane 182 can be a gas-permeable membrane but a liquid-permeable membrane. For example, the inner membrane 182 may include at least one of a non-woven filter membrane or a breathable membrane having micropores capable of blocking liquids. The inner membrane 182 may include polyethylene terephthalate (PET), polyethylene (PE), polypropylene (PP), and expanded polytetrafluoroethylene (EPTFE).

[0102] Tip 183 can be mounted on the underside of central structure 181c. Planarly, tip 183 can be positioned at the center of central structure 181c and can have a pointed end. Here, the tip of tip 183 can face outer membrane 184. Tip 183 can be separated from outer membrane 184. For example, the height of tip 183 can be less than the distance between central structure 181c and outer membrane 184. Tip 183 should not corrode due to gases generated inside housing 160 and can be made of rigid ceramic or plastic materials.

[0103] The outer membrane 184 can be joined to the open side of the frame 181 to seal the internal space of the frame 181. The outer membrane 184 can be mounted on the frame 181 in the form of a flat plate. The outer membrane 184 can be joined to the end of the sidewall 181b of the frame 181 by an adhesive. The outer membrane 184 can face the lower surface of the central structure 181c. The outer membrane 184 can be arranged horizontally relative to the central structure 181c (or the outer membrane 184 can be arranged to remain horizontal relative to the central structure 181c) and can be spaced apart from the central structure 181c at equal distances. In addition, the outer membrane 184 can be spaced apart from the tip 183 mounted on the central structure 181c. The outer membrane 184 can be formed of a membrane that is impermeable to gases and liquids. In addition, the outer membrane 184 can include a polymer compound that is not corroded by electrolytes. For example, the outer membrane 184 can be formed of a material similar to that of the diaphragm. For example, the outer membrane 184 can be formed of polyethylene, polypropylene, or a composite membrane of polyethylene and polypropylene. In addition, the outer membrane 184 can be in the form of a thin film that can be deformed into a certain shape by applying pressure.

[0104] like Figure 4 As shown, as the secondary battery 100 undergoes charge / discharge cycles, the outer membrane 184 may deform inward toward the frame 181 due to the increased internal gas pressure caused by the increase in internal gas. At this time, the outer membrane 184 may come into contact with the tip 183 and be damaged. Here, the tip 183 is located at the center of the central structure 181c, and therefore may be more likely to come into contact with the deformed outer membrane 184. The outer membrane 184 may deform when the internal pressure of the housing 160 exceeds a reference pressure.

[0105] When the outer membrane 184 is damaged in this manner, gas inside the housing 160 can flow through the damaged area of ​​the outer membrane 184 into the interior of the frame 181 of the gas adsorption structure 180. The gas flowing into the interior of the frame 181 of the gas adsorption structure 180 can pass through the inner membrane 182 via the central structure 181c and be adsorbed by the adsorbent contained within the inner membrane 182. In other words, when the gas inside the housing 160 increases due to increased internal pressure, the gas adsorption structure 180 can reduce the gas inside the housing 160 by adsorbing gas via the adsorbent. The gas adsorption structure 180 can increase the lifespan of the secondary battery 100 by delaying the operation of the safety vent 174. Furthermore, the gas adsorption structure 180 can prevent the housing 160 and the cover plate 171 from deforming due to gas by reducing the gas inside the housing 160.

[0106] The secondary battery according to the above embodiments can be used to manufacture battery packs.

[0107] Figure 5A and Figure 5B This is a perspective view illustrating a battery pack including an exemplary secondary battery 100 according to the present invention. (Refer to...) Figure 5A and Figure 5B The battery pack 300 may include a plurality of battery modules 200 and a housing 310 for accommodating the plurality of battery modules 200. For example, the housing 310 may include a first housing 311 and a second housing 312, which are joined together in a direction facing each other, with the plurality of battery modules 200 disposed between the first housing 311 and the second housing 312. The plurality of battery modules 200 may be electrically connected to each other using a busbar 251, and the plurality of battery modules 200 may be electrically connected to each other in series / parallel or a combination of series and parallel to obtain the desired electrical output. In the accompanying drawings, for ease of illustration, some components including busbars, cooling units, external terminals for electrically connecting the batteries, etc., are omitted. In some examples, the battery pack may be mounted on (or in) a vehicle. The vehicle may be, for example, an electric vehicle, a hybrid vehicle, or a plug-in hybrid vehicle. The vehicle may include a four-wheeled vehicle or a two-wheeled vehicle.

[0108] Figure 6A and Figure 6B These are perspective and side views illustrating vehicles 400 and 500 including an exemplary battery pack 300 according to the present invention.

[0109] exist Figure 6A In this configuration, the battery pack 300 may include a battery pack cover 311 as part of a vehicle bottom 410 and a battery pack frame 312 disposed below the vehicle bottom 410. The battery pack cover 311 may correspond to a first housing, and the battery pack frame 312 may correspond to a second housing. The battery pack cover 311 and the battery pack frame 312 may be integrally formed with the chassis 420. The vehicle bottom 410 separates the interior and exterior of the vehicle, and the battery pack frame 312 may be placed on the exterior of the vehicle.

[0110] like Figure 6B As shown, vehicle 500 can be formed by combining additional components such as an engine hood 510 at the front of the vehicle and fenders 520 respectively positioned at the front and rear of the vehicle into the vehicle body. Vehicle 500 includes a battery pack 300 comprising a battery pack cover 311 and a battery pack frame 312, and the battery pack 300 can be combined into the vehicle body.

[0111] While the foregoing embodiments have been provided for implementing the secondary battery according to the invention, it should be understood that the embodiments described herein are to be considered in a descriptive sense only and not for limiting purposes, and various changes in form and detail may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

Claims

1. A secondary battery, the secondary battery comprising: The electrode assembly includes a first electrode plate and a second electrode plate; A housing that houses the electrode assembly and has an end opening; A cover plate that seals one end opening of the housing; as well as A gas adsorption structure is installed on the lower surface of the cover plate and contains a gas adsorbent. The gas adsorbent is surrounded by an inner membrane, which is further surrounded by an outer membrane and a frame.

2. The secondary battery according to claim 1, wherein, The frame has an interior space provided by an upper plate fixed to the cover plate and sidewalls extending from the edge of the upper plate toward the electrode assembly.

3. The secondary battery according to claim 2, wherein, The outer membrane is joined to the end of the sidewall to seal the interior of the frame.

4. The secondary battery according to claim 2, wherein, The frame also includes a central structure installed across the sidewalls and dividing the interior space of the frame into an upper region and a lower region.

5. The secondary battery according to claim 4, wherein, The central structure has a hole or opening area to allow connection between the upper region and the lower region.

6. The secondary battery according to claim 4, wherein, The inner membrane, containing the gas adsorbent contained within it, is housed in the upper region, which is the upper side of the central structure in the frame.

7. The secondary battery according to claim 4, wherein, The central structure is positioned horizontally relative to the upper plate.

8. The secondary battery according to claim 4, further comprising a tip, the tip being mounted on the lower side of the central structure and having a pointed tip facing the outer membrane.

9. The secondary battery according to claim 8, wherein, In terms of the plane, the tip is positioned at the center of the central structure.

10. The secondary battery according to claim 8, wherein, The height of the tip is less than the distance from the central structure to the outer membrane.

11. The secondary battery according to claim 8, wherein, When the internal pressure of the housing increases, the outer membrane becomes concave and deformed into the frame, so as to be damaged by the tip.

12. The secondary battery according to claim 8, wherein, The tip is not corroded by the gas generated inside the housing and is made of a rigid ceramic or plastic material.

13. The secondary battery according to claim 4, wherein, The outer membrane and the central structure are arranged horizontally relative to each other.

14. The secondary battery according to claim 2, wherein, The sidewalls of the frame are all of equal height.

15. The secondary battery according to claim 1, wherein, The inner membrane allows gas to pass through but blocks liquids.

16. The secondary battery according to claim 1, wherein, The outer membrane is a membrane that blocks gases and liquids.

17. The secondary battery according to claim 1, wherein, The inner membrane is a non-woven filter membrane or a breathable membrane with micropores that block liquid.

18. The secondary battery according to claim 1, wherein, The gas adsorbent includes at least one of calcium carbonate, potassium carbonate, and sodium hydroxide.

19. The secondary battery according to claim 1, wherein, The outer membrane is in the shape of a flat plate.

20. The secondary battery according to claim 1, wherein, The outer membrane is a polyethylene, polypropylene, or a composite membrane of polyethylene and polypropylene.

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