Battery pack

Abstract

A battery pack including a lower case and an upper case that define an internal space, a plurality of battery cells provided within the internal space, and a pack gasket provided between the lower case and the upper case, the pack gasket including a first surface facing the upper case, a second surface opposite the first surface and facing the lower case, a first side portion facing the internal space, and a second side portion facing the outside of the battery pack, and a battery pack provided with a heat-resistant plastic member at least partially between the first side portion and the second side portion in any cross-section in the width direction is provided.

Description

Technical Field

[0001] The present invention relates to a battery pack, and more specifically, to a battery pack in which safety can be improved by maintaining the sealing performance of a pack gasket even when a flame is generated inside.

[0002] This application claims the benefit of priority based on Korean Patent Application No. 10-2022-0097560 filed on August 4, 2022, and Korean Patent Application No. 10-2023-0043322 filed on April 3, 2023, and all contents disclosed in the documents of the Korean patent applications are included as part of this specification.

Background Art

[0003] Unlike primary batteries, secondary batteries can be charged and discharged multiple times. Secondary batteries are widely used as an energy source for various wireless devices such as handsets, notebook computers, and wireless vacuum cleaners. In recent years, due to the improvement of energy density and economies of scale, the manufacturing cost per unit capacity of secondary batteries has decreased dramatically, and as the driving range of battery electric vehicles (BEVs) has increased to a level equivalent to that of fuel vehicles, the main usage of secondary batteries has shifted from mobile devices to mobility.

[0004] The latest trend in the technological development of secondary batteries for mobility is the improvement of energy density and safety. Here, the energy density of a secondary battery is the value obtained by dividing the maximum electrical energy that the secondary battery can store by the mass of the secondary battery. Since the high energy density of a secondary battery is directly related to the driving efficiency and driving range of mobility, various studies have been conducted to improve the energy density of secondary batteries.

Summary of the Invention

Problems to be Solved by the Invention

[0005] The technical problem to be achieved by the present invention is to provide a battery pack that can improve safety by maintaining the sealing performance of the pack gasket even when a flame occurs inside.

Means for Solving the Problem

[0006] In order to achieve the above technical problem, the present invention includes a pack case including a lower case and an upper case that define an internal space, a plurality of battery cells provided in the internal space, and a pack gasket provided between the lower case and the upper case. The pack gasket includes a first surface facing the upper case, a second surface on the opposite side of the first surface and facing the lower case, a first side portion facing the internal space, and a second side portion facing the outside of the pack case. The pack gasket provides a battery pack that includes at least a partially heat-resistant plastic member between the first side portion and the second side portion in any cross-section in the width direction.

[0007] In some embodiments, the heat-resistant plastic member is at least partially extended along the joint surface between the upper case and the lower case, and the heat-resistant plastic member can be disposed at a position closer to the internal space than the center between the first side portion and the second side portion.

[0008] In some embodiments, the pack gasket includes a gasket main body portion and the heat-resistant plastic member, the gasket main body portion includes a storage portion, and the heat-resistant plastic member can be disposed in the storage portion.

[0009] In some embodiments, the gasket main body portion may include a first portion interposed between the upper case and the lower case, and a second portion extending from the first portion into the internal space and extending along the side wall of the upper case and / or the lower case.

[0010] In some embodiments, in the thickness direction of the first portion, the dimensions of the heat-resistant plastic member may be even larger than the thickness of the first portion.

[0011] In some embodiments, the heat-resistant plastic member may be arranged to overlap the first portion over the entire thickness of the first portion.

[0012] In some embodiments, the heat-resistant plastic member may be formed integrally with or integrated with the gasket body portion. In some embodiments, the heat-resistant plastic member may be integrated with the gasket body portion by an insert molding method.

[0013] In some embodiments, the heat-resistant plastic member may include one or more of acrylonitrile-based resins, acrylic resins, benzimidazole-based resins, indoline-based resins, imide-based resins, amide-based resins, phenylene oxide-based resins, butylene terephthalate-based resins, fluorine-based resins, or copolymers thereof.

[0014] Another aspect of the present invention includes a pack case including a lower case and an upper case that define an internal space, a plurality of battery cells provided in the internal space, and a pack gasket provided between the lower case and the upper case. The pack gasket includes a heat-resistant plastic member and a gasket body portion that extends along the joint surface between the upper case and the lower case. The heat-resistant plastic member provides a battery pack integrated with the gasket body portion.

[0015] In some embodiments, the gasket body portion includes a storage portion, and the heat-resistant plastic member may be inserted into the storage portion.

[0016] In some embodiments, the heat-resistant plastic member may extend over at least the separation distance between the upper case and the lower case.

[0017] In some embodiments, the heat-resistant plastic member may be at least partially interposed between the upper case and the lower case.

[0018] In some embodiments, at least a part of the heat-resistant plastic member may protrude from between the upper case and the lower case toward the internal space.

[0019] In some embodiments, the heat-resistant plastic member may not be interposed between the upper case and the lower case.

Advantages of the Invention

[0020] The battery pack of the present invention has an effect that the safety can be improved by maintaining the sealing performance of the pack gasket even if a flame occurs inside.

[0021] The effects obtainable from the exemplary embodiments of the present invention are not limited to the effects mentioned above, and other effects not mentioned can be clearly derived and understood by those having ordinary knowledge in the technical field to which the exemplary embodiments of the present disclosure belong from the following description. That is, unintended effects associated with implementing the exemplary embodiments of the present disclosure can also be derived by those having ordinary knowledge in the technical field from the exemplary embodiments of the present disclosure.

Brief Description of the Drawings

[0022]

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[0023] Hereinafter, preferred embodiments of the concept of the present invention will be described in detail with reference to the accompanying drawings. However, the embodiments of the concept of the present invention can be modified into various different forms, and the scope of the concept of the present invention should not be construed as being limited by the embodiments described above. The embodiments of the concept of the present invention are preferably construed as being provided to more fully explain the concept of the present invention to those having average knowledge in the art. The same reference numerals mean the same elements throughout. Further, various elements and regions in the drawings are schematically drawn. Therefore, the concept of the present invention is not limited by the relative sizes or intervals depicted in the attached drawings.

[0024] Terms such as "first" and "second" may be used to describe various components, but the components are not limited by these terms. These terms are only used for the purpose of distinguishing one component from another. For example, without departing from the scope of the concept of the present invention, the first component may be named the second component, and conversely, the second component may be named the first component.

[0025] The terms used in this application are merely used to describe specific embodiments and are not intended to limit the concept of the present invention. Singular expressions include plural expressions unless the context clearly indicates a different meaning. In this application, expressions such as "including" and "having" are intended to specify the existence of features, numbers, steps, operations, components, parts, or combinations thereof described in the specification, and do not preclude the existence or addition possibility of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0026] Unless otherwise defined, all terms used herein include technical and scientific terms and have the same meaning as commonly understood by those of ordinary skill in the technical field to which the concept of the present invention belongs. Also, commonly used pre-defined terms can be interpreted to have a meaning consistent with what they mean in the context of the relevant technology, and it can be understood that they should not be interpreted as overly formal meanings unless explicitly defined here.

[0027] When a particular embodiment can be implemented otherwise, a specific order of steps may be performed differently from the described order. For example, two steps described consecutively may be performed substantially simultaneously or in an order reverse to the described order.

[0028] In the accompanying drawings, for example, due to manufacturing techniques and / or tolerances, deformations of the illustrated shapes may be expected. Therefore, embodiments of the present invention should not be construed as being limited to the specific shapes of the regions illustrated herein, and may include, for example, shape changes brought about during the manufacturing process. All terms "and / or" used herein include each of the recited components and all combinations of one or more of them. Also, the term "substrate" as used herein may mean the substrate itself or a laminated structure including the substrate and a predetermined layer or film formed on its surface. Further, in this specification, the "surface of the substrate" may mean the exposed surface of the substrate itself or the outer surface of a predetermined layer or film formed on the substrate.

[0029] (First Embodiment) FIG. 1 is a perspective view of a battery pack 100 according to an exemplary embodiment.

[0030] FIG. 2 is a perspective view showing some elements of the battery pack 100 according to an exemplary embodiment.

[0031] Referring to FIGS. 1 and 2, the battery pack 100 may include a lower case 110, a plurality of battery assemblies 120 in which battery cells are incorporated, a center beam 130, a plurality of exhaust devices 140, a plurality of first embedding guides 151, a plurality of second embedding guides 153, a pack gasket 160, and an upper case 170. The battery pack 100 is the final form of a battery system mounted on mobility or the like.

[0032] The pack case 101 corresponding to the housing of the battery pack 100 may include the lower case 110 and the upper case 170.

[0033] The lower case 110 may provide an internal space 119 for mounting a plurality of battery assemblies 120. In some embodiments, the lower case 110 may include a plate portion 110P and side walls 110S. Define two directions substantially parallel to the plate portion 110P as the X direction and the Y direction, and define the direction substantially perpendicular to the plate portion 110P of the lower case 110 as the Z direction. Each of the X direction, the Y direction, and the Z direction may be substantially perpendicular to each other. Unless otherwise specified, the definition of the direction is the same for the following drawings.

[0034] A plurality of battery assemblies 120 may be arranged on the plate portion 110P of the lower case 110. The plate portion 110P may support a plurality of battery assemblies 120. The plate portion 110P may include substantially parallel upper and lower surfaces. The upper surface of the plate portion 110P may face a plurality of battery assemblies 120. The lower surface of the plate portion 110P is the opposite surface of the upper surface of the plate portion 110P.

[0035] The side walls 110S may horizontally surround a plurality of battery assemblies 120. The side walls 110S may protect a plurality of battery assemblies 120 from the lateral direction. The side walls 110S may include a first side wall 111, a second side wall 112, a third side wall 113, and a fourth side wall 114. The first to fourth side walls 111, 112, 113, 114 may be fixed to each other by methods such as friction stir welding and spot welding, and are not particularly limited.

[0036] The first side wall 111 and the second side wall 112 may be substantially perpendicular to the Y direction. Each of the third side wall 113 and the fourth side wall 114 may be substantially perpendicular to the X direction. In some embodiments, the first side wall 111 and the second side wall 112 may cover the side surfaces of the plate portion 110P. In some embodiments, the third side wall 113 and the fourth side wall 114 may be arranged on the plate portion 110P.

[0037] In some embodiments, the first to fourth sidewalls 111, 112, 113, 114 can be provided by an extrusion process. According to an exemplary embodiment, the first to fourth sidewalls 111, 112, 113, 114 can include an internal empty space, whereby the sidewall 110S can be lightweighted. According to an exemplary embodiment, the empty space of the first to fourth sidewalls 111, 112, 113, 114 can be either a gas venting path or a coolant channel.

[0038] Hereinafter, the technical idea of the present invention will be described with reference to an embodiment in which each of the plurality of battery assemblies 120 does not include a module frame. However, this is a non-limiting example and does not limit the technical idea of the present invention in any sense. A person of ordinary skill in the art can easily reach, based on what is described herein, a battery pack in which a plurality of battery assemblies including a module frame are employed, as well as an embodiment in which battery cells are directly mounted in a pack case.

[0039] The center beam 130 can isolate elements mounted on the lower case 110 from each other. Thereby, the center beam 130 can protect the plurality of battery assemblies 120 and at the same time prevent an undesired short circuit between them.

[0040] The center beam 130 can extend between the third sidewall 113 and the fourth sidewall 114. The center beam 130 can extend in the X direction. The center beam 130 can be in contact with the third sidewall 113 and the fourth sidewall 114. The center beam 130 can isolate the plurality of battery assemblies 120 from each other. The center beam 130 can be interposed between the plurality of battery assemblies 120.

[0041] The arrangement of the center beam 130 and the plurality of battery assemblies 120 disclosed in FIG. 1 is a non-limiting example and does not limit the technical idea of the present invention in any sense. A person of ordinary skill in the art can easily arrive at a battery pack including various arrangements and numbers of center beams and battery assemblies based on what is described herein.

[0042] A plurality of exhaust devices 140 may be coupled to the fourth side wall 114. The fourth side wall 114 may include a plurality of exhaust holes connected to the plurality of exhaust devices 140. The plurality of exhaust holes may be configured to provide a path for discharging gas and heat inside the battery pack 100.

[0043] The plurality of exhaust devices 140 may be configured to slow down thermal propagation by discharging high-temperature gas inside the battery pack 100 to the outside when at least one of the plurality of battery assemblies 120 is in a thermal runaway state.

[0044] Here, the thermal runaway of the plurality of battery assemblies 120 is a state in which the temperature change of the plurality of battery assemblies 120 further accelerates the temperature change, which is an uncontrollable positive feedback. The plurality of battery assemblies 120 in the thermal runaway state show a rapid temperature rise and can discharge a large amount of high-pressure gas and combustion residues.

[0045] The plurality of first embedding guides 151 may be arranged on the side wall 110S. The plurality of first embedding guides 151 may be arranged on the corner 110C of the upper surface 110a (see FIG. 3) of the side wall 110S. The plurality of first embedding guides 151 may be coupled to the corner 110C of the upper surface 110a (see FIG. 3) of the side wall 110S. The plurality of first embedding guides 151 may be partially embedded in the side wall 110S. The plurality of first embedding guides 151 may partially protrude from the side wall 110S.

[0046] The plurality of second embedded guides 153 can be arranged on the side wall 110S. The plurality of second embedded guides 153 can be arranged on the upper surface 110a (see FIG. 3) of the side wall 110S. The plurality of second embedded guides 153 can be interposed between the corners 110C of the side wall 110S. The plurality of second embedded guides 153 can be interposed between the plurality of first embedded guides 151. The plurality of second embedded guides 153 can be coupled to the upper surface 110a (see FIG. 3) of the side wall 110S. The plurality of second embedded guides 153 can be partially embedded in the side wall 110S. The plurality of second embedded guides 153 can partially protrude from the side wall 110S.

[0047] Each of the plurality of first embedded guides 151 and second embedded guides 153 can include a metallic substance. Each of the plurality of first embedded guides 151 and second embedded guides 153 can include, for example, aluminum. Each of the plurality of first embedded guides 151 and second embedded guides 153 can also include steels such as, for example, carbon steel, nickel steel, chromium steel, nickel chromium steel, and manganese steel.

[0048] The battery pack 100 can further include electrical components. In some embodiments, the electrical components can be mounted on the lower case 110. In some embodiments, the electrical components can be arranged between the fourth side wall 114 where the exhaust device 140 is installed and the plurality of battery assemblies 120. In some embodiments, the electrical components can include any electronic elements necessary to drive the battery pack.

[0049] In some embodiments, the electrical components can include, for example, a BMS (battery management system). The BMS can be configured to perform monitoring, balancing, and control of the battery pack. In some embodiments, the monitoring of the battery pack 100 can include measuring the voltage and current of specific nodes inside the plurality of battery assemblies 120, and measuring the temperature at a set position inside the battery pack 100. In some embodiments, the battery pack 100 can include measuring instruments for measuring the voltage, current, and temperature described above.

[0050] Balancing of the battery pack 100 is an operation to reduce the deviation among a plurality of battery assemblies 120. Control of the battery pack 100 includes preventing the occurrence of overcharge, overdischarge, and overcurrent. Through monitoring, balancing, and control, the battery pack 100 can operate under optimal conditions, thereby preventing or reducing the shortening of the lifespan of each of the plurality of battery assemblies 120.

[0051] The electrical component may further include a cooling device, a PRA (power relay assembly), a safety plug, etc. The cooling device may include a cooling fan. The cooling fan can prevent overheating of each of the plurality of battery assemblies 120 by circulating the air inside the battery pack 100. The PRA may be configured to supply or cut off the power of the high-voltage battery to an external load (e.g., the motor of a vehicle). The PRA can protect the plurality of battery assemblies 120 and the external load (e.g., the motor of a vehicle) by cutting off the power supply to the external load (e.g., the motor of a vehicle) in a situation where an abnormal voltage such as a voltage surge occurs.

[0052] The battery pack 100 may further include a plurality of busbars configured to electrically connect the plurality of battery assemblies 120. The plurality of battery assemblies 120 can be connected in series and / or in parallel by the plurality of busbars. Thereby, the battery pack 100 can be configured to output a high voltage to an external load (e.g., the motor of a vehicle).

[0053] The packing gasket 160 may include a material having elasticity corresponding to the applied pressure. The packing gasket 160 may include, for example, rubber synthesized from a material such as EPDM (ethylene-propylene diene monomer). When the lower case 110 and the upper case 170 are coupled, the packing gasket 160 may be interposed between the lower case 110 and the upper case 170. The lower case 110 and the upper case 170 may press the packing gasket 160 so that some deformation occurs in the packing gasket 160. Thereby, the battery pack 100 may be sealed, and external fluid may be blocked from the internal space of the battery pack 100.

[0054] The upper case 170 may be coupled to the lower case 110. In some embodiments, the upper case 170 may include a main surface and an edge. The main surface may cover elements mounted on the battery pack 100 such as a plurality of battery assemblies 120 and electrical components. The edge is a surface in contact with the lower case 110. In some embodiments, the upper case 170 may have a flat plate shape, in which case the edge may horizontally surround the main surface. In some embodiments, the main surface may be elevated compared to the edge, and the edge and the main surface may be connected by a bent portion.

[0055] The upper case 170 may be coupled to the side wall 110S of the lower case 110 by a plurality of first embedding guides 151 and second embedding guides 153. According to an exemplary embodiment, the battery pack 100 may further include an element coupled to the plurality of first embedding guides 151 and second embedding guides 153 to fix the upper case 170 to the side wall 110S of the lower case 110. The element may include, but is not limited to, bolts and nuts.

[0056] FIG. 3 is a partial cross-sectional perspective view showing a cross-section obtained by cutting the battery pack 100 of FIG. 1 along the line III-III' of FIG. 2.

[0057] Referring to FIG. 3, the first side wall 111 may include a hollow channel H. The first side wall 111 including the hollow channel H may be reduced in weight to correspond to the volume of the hollow channel H. Further, the hollow channel H may be utilized as a venting flow path for gas generated within the battery pack 100, or may be utilized as a flow path for a cooling medium.

[0058] The upper case 170 covers the lower case 110 and is coupled to the upper surface 110a of the lower case. In some embodiments, the edge of the upper case 170 is coupled to the upper surface 110a of the lower case. In some embodiments, the upper case 170 may be configured in a flat plate shape. Alternatively, as illustrated in FIG. 3, the edge of the upper case 170 may be formed by a flange portion 172, and the inner portion of the edge of the upper case 170 may be configured by a cover portion 171 that is bent upward from the flange portion 172. In this case, the height of the cover portion 171 is formed higher than the height of the flange portion 172. Thus, when the upper case 170 is configured by the flange portion 172 and the cover portion 171, the bending rigidity is even stronger than that of the flat plate-shaped upper case 170, and the upper case 170 can be made more robust as a whole. Also, since the distance between the upper case 170 and the battery assembly 120 becomes larger, venting of gas generated within the battery pack 100 can be made easier through this distance.

[0059] A pack gasket 160 is interposed between the upper case 170 and the lower case 110.

[0060] The pack gasket 160 may have a form corresponding to the shape of the side wall 110S of the lower case 110 and may be provided along the upper surface 110a of the lower case. In some embodiments, the pack gasket 160 may include a plurality of through fastening holes 160a formed at predetermined intervals.

[0061] The pack gasket 160 includes a gasket body portion 162 and a heat-resistant plastic member 164.

[0062] FIG. 4 is a cross-sectional perspective view showing a main part of the pack gasket 160 according to an embodiment of the present invention.

[0063] Referring to FIGS. 3 and 4, the pack gasket 160 includes a first surface 160t facing the upper case 170 and a second surface 160b facing the lower case 110. The first surface 160t and the second surface 160b may be surfaces on opposite sides of each other. Further, the pack gasket 160 includes a first side portion 160sa facing the internal space 119 (see FIG. 2) and a second side portion 160sb facing the outside of the pack case 101. The first side portion 160sa and the second side portion 160sb are located on opposite sides of each other.

[0064] In some embodiments, the pack gasket 160 includes a heat-resistant plastic member 164 between the first side portion 160sa and the second side portion 160sb in any cross-section in the width direction. In any cross-section, the entire cross-section may be the heat-resistant plastic member 164, or a part of the cross-section may be the heat-resistant plastic member 164.

[0065] In some embodiments, the material of the heat-resistant plastic member 164 can be selected such that there is no or only slight deformation at high temperatures and no morphological change due to melting or carbonization. Specifically, the material of the heat-resistant plastic member 164 can be selected such that there is no morphological change due to melting or carbonization at a temperature of 600 °C or higher, 700 °C or higher, 800 °C or higher, or 800 °C to 1,000 °C for a predetermined time.

[0066] The heat-resistant plastic member 164 may contain one or more of acrylonitrile-based resins, acrylic resins, benzimidazole-based resins, indoline-based resins, imide-based resins, amide-based resins, phenylene oxide-based resins, butylene terephthalate-based resins, fluorine-based resins, or copolymers thereof. More specifically, the heat-resistant plastic member 164 may be, for example, one or more selected from the group consisting of modified polyphenylene oxide (MPPO), modified polysulfone (MPSU), polycarbonate (PC), polyamide, polysulfone (PSU), polyethersulfone (PES), polyetherimide (PEI), polyphenylene sulfide, liquid crystal polymer, polyetheretherketone (PEEK), and mixtures thereof, but the present invention is not limited thereto.

[0067] In some embodiments, the heat-resistant plastic member 164 may include a phenylene oxide-based resin such as polyphenyleneoxide (PPO), an amide-based resin such as nylon, a mixture thereof, or a copolymer thereof. In some embodiments, the phenylene oxide-based resin and the amide-based resin may be applied in a form in which some repeating units are modified.

[0068] In some embodiments, the heat-resistant plastic member 164 may further include an inorganic filler and / or a fiber structure.

[0069] The inorganic filler may be, for example, silica, alumina, potassium titanate, wollastonite, zonnolite, dowsonite, acicular MgO, acicular magnesium hydroxide, aluminum borate, etc., but is not limited thereto.

[0070] The fiber structure may be, for example, glass fiber, carbon fiber, slag fiber, phosphate fiber, gypsum fiber, aramid fiber, etc., but is not limited thereto.

[0071] The gasket main body 162 may include, for example, rubber synthesized from a substance such as EPDM (ethylene-propylene diene monomer).

[0072] Even if a flame occurs inside the battery pack 100 and reaches the inside of the upper case 170 and the lower case 110, the heat-resistant plastic member 164 can protect at least a part of the gasket main body 162. In other words, by the heat-resistant plastic member 164 protecting the gasket main body 162 at least partially, the sealing performance of the pack gasket 160 can be maintained.

[0073] In some embodiments, the gasket main body 162 may include a first portion P1 interposed between the upper case 170 and the lower case 110, and a second portion P2 extending from the first portion P1 toward the internal space 119 (see FIG. 2).

[0074] The first portion P1 may extend along the joint surface of the upper case 170 and the lower case 110 between the upper case 170 and the lower case 110, for example, along the upper surface 110a of the lower case. The width of the first portion P1 does not have to be the same as the width of the upper surface 110a of the lower case, but may be about 50% or more, about 55% or more, about 60% or more, about 65% or more, about 70% or more, about 75% or more, about 80% or more, about 85% or more, about 90% or more, or about 95% or more of the width of the upper surface 110a of the lower case.

[0075] The second part P2 is integral with the first part P1 and is not interposed between the upper case 170 and the lower case 110. The second part P2 can extend along the side wall of the upper case 170 and / or the side wall of the lower case 110 at the side of the first part P1. In FIG. 3, an example in which the second part P2 extends along the side wall of the lower case 110 is illustrated, but the present invention is not limited thereto.

[0076] The gasket main body portion 162 includes a storage portion 162R, and the heat-resistant plastic member 164 can be stored in the storage portion 162R. In some embodiments, the heat-resistant plastic member 164 can be inserted into the storage portion 162R. In some embodiments, the heat-resistant plastic member 164 can be integrated with the gasket main body portion 162 by an insert molding method.

[0077] In some embodiments, the heat-resistant plastic member 164 can be formed integrally with the gasket main body portion 162. In some embodiments, the heat-resistant plastic member 164 can be integrated with the gasket main body portion 162. Here, the fact that the heat-resistant plastic member 164 is integrated with the gasket main body portion 162 means that after the heat-resistant plastic member 164 and the gasket main body portion 162 are separately formed, they are integrated by a subsequent process.

[0078] The heat-resistant plastic member 164 can be disposed at a position closer to the internal space 119 than the center CL of the first side portion 160sa and the second side portion 160sb. Since the heat-resistant plastic member 164 is disposed at a position closer to the internal space 119 than the center CL, most of the gasket main body portion 162 is disposed at a position further away from the internal space 119 than the heat-resistant plastic member 164. Even if a flame occurs and the flame reaches the inside of the upper case 170 and the lower case 110, most of the gasket main body portion 162 is protected by the heat-resistant plastic member 164, so that the sealing performance of the pack gasket 160 can be maintained well.

[0079] In some embodiments, the dimension of the heat-resistant plastic member 164 in the thickness direction (the vertical direction in FIG. 4) of the first portion P1 may be the same as or larger than the thickness of the first portion P1. Since the first portion P1 is interposed between the upper case 170 and the lower case 110, it can be said that the sealing performance is ensured by the first portion P1. If the dimension of the heat-resistant plastic member 164 in the thickness direction (the vertical direction in FIG. 4) of the first portion P1 is even larger than the thickness of the first portion P1, the first portion P1 can be protected from the flame over at least the entire thickness of the first portion P1. Therefore, the sealing performance of the pack gasket 160 can be maintained well.

[0080] In some embodiments, when the upper case 170 and the lower case 110 are coupled, the upper case 170 and the lower case 110 are separated from each other by at least the thickness of the first portion P1. At this time, in the thickness direction (the vertical direction in FIG. 4) of the first portion P1, the heat-resistant plastic member 164 can be extended over at least the separation distance. If the dimension of the heat-resistant plastic member 164 in the thickness direction (the vertical direction in FIG. 4) of the first portion P1 is even larger than the separation distance, the first portion P1 interposed between the upper case 170 and the lower case 110 can be protected from the flame. Therefore, the sealing performance of the pack gasket 160 can be maintained well.

[0081] In some embodiments, the heat-resistant plastic member 164 may not be interposed between the upper case 170 and the lower case 110. In this case, the storage portion 162R may be provided in the second portion P2.

[0082] In some embodiments, the heat-resistant plastic member 164 may be arranged to overlap the first portion P1 over the entire thickness of the first portion P1 in the lateral direction. Since it overlaps the first portion P1 over the entire thickness of the first portion P1, the first portion P1 can be protected from the flame over the entire thickness of the first portion P1. Therefore, the sealing performance of the pack gasket 160 can be maintained well.

[0083] (Additional Embodiment) FIG. 5 is a partial cross-sectional perspective view showing a cross-section of the battery pack 100 according to another embodiment of the present invention taken along the line III-III' of FIG. 2. The embodiment illustrated in FIG. 5 is substantially the same as the embodiment illustrated in FIG. 3 except that the cross-sectional shape of the heat-resistant plastic member 164 is different. Therefore, hereinafter, the description will focus on the differences between the two embodiments, and overlapping descriptions will be omitted.

[0084] Referring to FIG. 5, the heat-resistant plastic member 164 is partially interposed between the upper case 170 and the lower case 110. In this case, the cross-section of the heat-resistant plastic member 164 may have an inverted L-shape. Also, a part of the heat-resistant plastic member 164 may have a form protruding from between the upper case 170 and the lower case 110 toward the internal space 119 (see FIG. 2).

[0085] Since the heat-resistant plastic member 164 of the present embodiment is partially interposed between the upper case 170 and the lower case 110, it may be possible to more reliably protect the first portion P1 of the gasket main body portion 162 from the flame. Therefore, the sealing performance of the pack gasket 160 can be maintained more excellently.

[0086] FIG. 6 is a partial cross-sectional perspective view showing a cross-section obtained by cutting the battery pack 100 according to another embodiment of the present invention along the line III-III' in FIG. 2. The embodiment illustrated in FIG. 6 is substantially the same as the embodiment illustrated in FIG. 5, except that the cross-sectional shape of the heat-resistant plastic member 164 is different. Therefore, below, the description will focus on the differences between the two embodiments, and overlapping descriptions will be omitted.

[0087] Referring to FIG. 6, the dimension of the heat-resistant plastic member 164 in the thickness direction of the first portion P1 is smaller than the thickness of the first portion P1. However, the heat-resistant plastic member 164 is partially interposed between the upper case 170 and the lower case 110. Also, a part of the heat-resistant plastic member 164 may have a form that protrudes from between the upper case 170 and the lower case 110 toward the internal space 119 (see FIG. 2).

[0088] From the point that the dimension of the heat-resistant plastic member 164 in the thickness direction decreases, it can be said that the performance of protecting the first portion P1 from the flame somewhat decreases. However, since the heat-resistant plastic member 164 is partially interposed between the upper case 170 and the lower case 110, the performance of protecting the first portion P1 from the flame as a whole may not be impaired.

[0089] Also, since the width of the heat-resistant plastic member 164 is somewhat wider and the insertion depth is shallow, the production of the pack gasket 160 according to the present embodiment may be easy and advantageous for mass production.

[0090] FIG. 7 is a partial cross-sectional perspective view showing a cross-section of the battery pack 100 according to another embodiment of the present invention taken along line III-III' in FIG. 2. The embodiment illustrated in FIG. 7 is different from the embodiments illustrated in FIGS. 3, 5, and 6 in that the entire heat-resistant plastic member 164 is interposed between the upper case 170 and the lower case 110. Hereinafter, the description will focus on the differences from other embodiments, and duplicate descriptions will be omitted.

[0091] Referring to FIG. 7, the entire pack gasket 160 is interposed between the upper case 170 and the lower case 110. That is, not only the gasket main body portion 162 but also the entire heat-resistant plastic member 164 is interposed between the upper case 170 and the lower case 110. The heat-resistant plastic member 164 can extend along the side surface of the gasket main body portion 162. The heat-resistant plastic member 164 is located on the inner space side of the gasket main body portion 162.

[0092] The gasket main body portion 162 and the heat-resistant plastic member 164 can be joined in any manner. For example, the gasket main body portion 162 and the heat-resistant plastic member 164 can be joined to each other by an insert molding method. However, the present invention is not limited thereto.

[0093] FIG. 8 is a partial cross-sectional perspective view showing a cross-section of the battery pack 100 according to another embodiment of the present invention taken along line III-III' in FIG. 2.

[0094] Referring to FIG. 8, a protruding projection P is provided on the upper surface 110a of the lower case. Even if a flame occurs inside the battery pack 100 and the flame reaches the inside of the upper case 170 and the lower case 110, the protruding projection P blocks the pack gasket 160, so that the flame cannot reach the pack gasket 160. Further, even if thermal energy is transmitted to the pack gasket 160 through the protruding projection P by the flame, the heat-resistant plastic member 164 protects the gasket body portion 162, so that the gasket body portion 162 can maintain its sealing performance.

[0095] The protruding projection P may be located on the upper surface 110a of the lower case along the side surface of the pack gasket 160. In some embodiments, the protruding projection P may be formed integrally with the lower case 110. In some embodiments, the protruding projection P may be separately manufactured and then integrated with the upper surface 110a of the lower case by a method such as welding.

[0096] FIG. 9 is a partial perspective view of the battery pack 100 of the present embodiment.

[0097] The upper surface view of FIG. 9 shows a state where the pack gasket 160 is not installed on the lower case 110, and the lower drawing of FIG. 9 shows a state where the pack gasket 160 is installed on the lower case 110.

[0098] As described above, the first to fourth side walls 111, 112, 113, and 114 can be fixed to each other by methods such as friction stir welding and spot welding. For example, the first side wall 111 and the fourth side wall 114 are arranged perpendicular to each other, and the respective ends can be joined by welding. As a result, welding portions W1 and W2 are formed at the corner portion where the first side wall 111 and the fourth side wall 114 are joined. Specifically, the welding portions W1 and W2 are formed on the upper surface of the corner portion and the side edge of the corner portion.

[0099] Due to the characteristics of welding, the welded portion W1 may protrude somewhat from the upper surface 110a of the lower case. Such protrusion may prevent the pack gasket 160 from being in close contact with the upper surface 110a of the lower case, so flattening is required. However, if the protruding projection P extends to the corner portion, it becomes very difficult to flatten the protrusion of the welded portion W1, and the production efficiency decreases.

[0100] In the battery pack 100 of the present embodiment, in view of such a point, in the vicinity of the corner portion, the protruding projection P may not be provided over a predetermined length range A. In this case, the pack gasket 160 at the corner portion may be vulnerable to the flame. In preparation for such a case, it is necessary to reinforce the pack gasket 160 at the corner portion. FIG. 10 is a partial perspective view of the lower case 110 with the pack gasket 160 having the corner portion reinforced.

[0101] Referring to FIG. 10, the protruding projection P is omitted at the corner portion, and the pack gasket 160 can extend toward the internal space at the portion where the protruding projection P is omitted. A heat-resistant plastic member 164 can be provided at the portion of the pack gasket 160 extending toward the internal space.

[0102] In some embodiments, the gasket body portion 162 belonging to the second portion P2 can extend horizontally from the gasket body portion 162 belonging to the first portion P1 toward the internal space. Further, the gasket body portion 162 belonging to the second portion P2 can extend vertically along the first side wall 111 and the fourth side wall 114. A storage portion is formed in the second portion P2 of the gasket body portion 162, and a heat-resistant plastic member 164 can be provided in the storage portion.

[0103] Ordinary technicians should note that the configuration of the pack gasket 160 at the corner is not limited to that illustrated in FIG. 10, and various embodiments described with reference to FIGS. 5 to 7 can be applied by suitable modifications. Also, in FIG. 10, the corner where the first side wall 111 and the fourth side wall 114 are in contact is described, but ordinary technicians can apply the same to other corners as well.

[0104] In FIG. 10, the side surface of the heat-resistant plastic member 164 is not exposed and is shown to be surrounded by the gasket body portion 162, but the present invention is not limited thereto. In some embodiments, the side wall of the second portion P2 extending vertically along the first side wall 111 and the fourth side wall 114 may include a hole exposing the heat-resistant plastic member 164.

[0105] In the battery pack 100 of the embodiment described with reference to FIGS. 9 and 10, in the portion where the first to fourth side walls 111, 112, 113, 114 extend horizontally, the pack gasket 160 can be protected by the protruding projection P, particularly the first portion P1 of the gasket body portion 162. Also, in the battery pack 100, in the corner where the first to fourth side walls 111, 112, 113, 114 are in contact with each other, the first portion P1 can be protected by the heat-resistant plastic member 164 provided on the gasket body portion 162. As a result, the entire first portion P1 interposed between the upper case 170 and the lower case 110 is protected, and the sealing performance of the pack gasket 160 can be maintained even when exposed to high temperature and / or flame.

[0106] As described above, the embodiments of the present invention have been described in detail. However, those having ordinary knowledge in the technical field to which the present invention pertains can implement the present invention with various modifications without departing from the spirit and scope of the present invention defined in the appended claims. Therefore, future changes to the embodiments of the present invention must not deviate from the technology of the present invention.

Description of Reference Numerals

[0107] 100 Battery Pack 101 Packing Case 110 Lower Case 110C Corner 110P Plate Portion 110S Side Wall 111 First Side Wall 112 Second Side Wall 113 Third Side Wall 114 Fourth Side Wall 119 Internal Space 120 Battery Assembly 130 Center Beam 140 Exhaust Device 151 First Embedding Guide 153 Second Embedding Guide 160 Pack Gasket 160 Gasket 160a Through-Fastening Hole 160b Second Surface 160sa First Side Portion 160sb Second Side Portion 160t First Surface 162 Gasket Body Portion 162R Storage Portion 164 Heat-Resistant Plastic Member 170 Upper Case 171 Cover Portion 172 Flange Portion CL Center H Hollow Channel MgO Needle-Like P Protruding Projection P1 First Portion P2 Second Portion W1 Weld Portion W2 Weld Portion

Claims

1. A battery pack including a lower case and an upper case that define an internal space, a plurality of battery cells provided within the internal space, and a pack gasket provided between the lower case and the upper case, wherein the pack gasket includes a first surface facing the upper case, a second surface opposite to the first surface and facing the lower case, a first side portion facing the internal space, and a second side portion facing the outside of the pack case, and the pack gasket includes at least partially a heat-resistant plastic member between the first side portion and the second side portion in any cross-section in the width direction. A battery pack.

2. The heat-resistant plastic member is at least partially extended along the joint surface between the upper case and the lower case, The heat-resistant plastic member is disposed at a position closer to the internal space than the center between the first side portion and the second side portion. The battery pack according to claim 1.

3. The pack gasket includes a gasket main body portion and the heat-resistant plastic member, The gasket main body portion includes a storage portion, The heat-resistant plastic member is disposed within the storage portion. The battery pack according to claim 1 or 2.

4. The gasket main body portion includes a first portion interposed between the upper case and the lower case, and a second portion extended from the first portion into the internal space and extended along the side wall of the upper case and / or the lower case, The battery pack according to claim 3.

5. The battery pack according to claim 4, wherein, in the thickness direction of the first part, the dimension of the heat-resistant plastic member is larger than the thickness of the first part.

6. The battery pack according to claim 4, wherein the heat-resistant plastic member is arranged so as to overlap the first part over the entire thickness of the first part.

7. The battery pack according to claim 3, wherein the heat-resistant plastic member is formed integrally with or integrated with the gasket main body.

8. The battery pack according to claim 7, wherein the heat-resistant plastic member is integrated with the gasket main body by an insert molding method.

9. The battery pack according to claim 7, wherein the heat-resistant plastic member contains one or more of an acrylonitrile-based resin, an acrylic resin, a benzimidazole-based resin, an indoline-based resin, an imide-based resin, an amide-based resin, a polyphenylene oxide-based resin, a butylene terephthalate-based resin, a fluororesin, or a copolymer thereof.

10. A pack case including a lower case and an upper case that define an internal space, A plurality of battery cells provided in the internal space, A pack gasket provided between the lower case and the upper case, and The pack gasket includes a heat-resistant plastic member and a gasket main body that extend along the joint surface between the upper case and the lower case, The heat-resistant plastic member is integrated with the gasket main body, the battery pack.

11. The gasket main body includes a storage portion, The battery pack according to claim 10, wherein the heat-resistant plastic member is inserted into the storage portion.

12. The heat-resistant plastic member is the battery pack according to claim 10, which extends at least over the separation distance between the upper case and the lower case.

13. The heat-resistant plastic member is the battery pack according to claim 10, which is at least partially interposed between the upper case and the lower case.

14. The heat-resistant plastic member is the battery pack according to claim 13, at least a part of which protrudes from between the upper case and the lower case toward the internal space.

15. The heat-resistant plastic member is the battery pack according to claim 10, which is not interposed between the upper case and the lower case.

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