Battery pack

Abstract

There is provided a battery pack including: a pack case including a lower case and an upper case defining an internal space; a plurality of battery cells located in the internal space; a separator positioned between the bottom surface of the pack case and the plurality of battery cells; and a thermally conductive resin layer between the separator and the plurality of battery cells, in which the separator is bonded to the thermally conductive resin layer with a first adhesive strength per unit area, and the first adhesive strength is lower than a second adhesive strength per unit area between the pack case and the thermally conductive resin layer when the pack case and the thermally conductive resin layer are adhered to each other.

Description

Technical Field

[0001] This disclosure relates to a battery pack, and more specifically, to a battery pack in which the desired battery cell can be easily removed from the battery pack housing and which offers greatly improved ease of maintenance.

[0002] This application claims the benefit of priority based on Korean Patent Application No. 10-2023-0048545, filed on April 13, 2023, the entire contents of which are incorporated herein by reference. Background Technology

[0003] Unlike primary batteries, secondary batteries can be charged and discharged multiple times. They are already widely used as a power source for various types of wireless devices, such as mobile phones, laptops, and cordless vacuum cleaners. Recently, with the significant reduction in manufacturing costs per unit capacity due to increased energy density and economies of scale, and with battery electric vehicles (BEVs) achieving driving ranges comparable to gasoline-powered vehicles, the primary use of secondary batteries has shifted from mobile devices to vehicles.

[0004] Recently, there has been an increasing demand for high-capacity battery packs applicable to electric vehicles and other applications. In high-capacity battery packs installed in vehicles, thermal events may occur during the charging and discharging of multiple individual cells due to temperature rise in some cells. In certain situations, follow-up measures, such as replacing the defective cell with another cell, must be implemented. Therefore, a method that facilitates such follow-up measures is needed. Summary of the Invention

[0005] Technical issues This disclosure aims to provide a battery pack that allows for easy removal of target battery cells from the battery pack housing, thereby significantly improving the convenience of maintenance.

[0006] Technical solution One aspect of this disclosure provides a battery pack comprising: a battery pack housing including a lower housing and an upper housing defining an internal space; a plurality of battery cells located in the internal space; a separator located between a bottom surface of the battery pack housing and the plurality of battery cells; and a thermally conductive resin layer located between the separator and the plurality of battery cells, wherein the separator is bonded to the thermally conductive resin layer with a first adhesive strength per unit area, and the first adhesive strength is lower than a second adhesive strength per unit area between the battery pack housing and the thermally conductive resin layer when the battery pack housing and the thermally conductive resin layer are bonded to each other.

[0007] In some embodiments, the first adhesive strength may be in the range of about 10% to about 70% of the second adhesive strength.

[0008] In some embodiments, the thermally conductive resin layer may be disposed only between the separator and multiple battery cells. In some embodiments, the thermally conductive resin layer may not be in contact with the battery pack casing.

[0009] In some embodiments, the separator may have adhesive strength relative to the battery pack housing.

[0010] In some embodiments, the plurality of battery cells may include at least one battery cell stack, the surface of the at least one battery cell stack facing the bottom surface may face the separator, and the width of the separator may be less than the width of the surface of the at least one battery cell stack. In some embodiments, the separator may extend along the side surface of the at least one battery cell stack.

[0011] In some embodiments, the separator may include a cut line running through the separator, and the cut line may pass between at least one cell stack and the bottom surface.

[0012] In some embodiments, the thermally conductive resin layer may be disposed only between the surface of at least one battery cell stack facing the bottom surface and the separator. In some embodiments, one surface of the thermally conductive resin layer may contact the separator, and the other surface of the thermally conductive resin layer may contact the surface of at least one battery cell stack.

[0013] In some embodiments, the plurality of battery cells may include at least one battery cell stack, and the separator may include a first separator and a second separator. The first separator may be located at one end of the at least one battery cell stack between the at least one battery cell stack and the bottom surface, and the second separator may be spaced apart from the first separator and located at the other end of the at least one battery cell stack between the at least one battery cell stack and the bottom surface.

[0014] In some embodiments, at least one battery cell stack can directly face the bottom surface between the first and second separators.

[0015] Another aspect of this disclosure provides a battery pack comprising: a plurality of battery cells, the plurality of battery cells being stacked in a first direction in a vertical coordinate system defined by a first direction, a second direction, and a third direction perpendicular to each other; a battery pack housing including a lower housing and an upper housing defining an internal space for accommodating the plurality of battery cells; a separator located between a bottom surface of the battery pack housing and the plurality of battery cells; and a thermally conductive resin layer located between the separator and the plurality of battery cells, wherein the separator is configured to separate from the thermally conductive resin layer when a shear force is applied to the thermally conductive resin layer.

[0016] In some embodiments, the thermally conductive resin layer may not be in contact with the battery pack housing.

[0017] In some embodiments, the lower housing may include sidewalls and crossbeams running through the lower housing, and the spacer may be configured to be attached to and / or detached from the sidewalls and / or crossbeams.

[0018] Beneficial effects In the battery pack disclosed herein, the target battery cell can be easily removed from the battery pack housing, thereby significantly improving the convenience of maintenance.

[0019] The effects achievable by the exemplary embodiments of this disclosure are not limited to those described above, and those skilled in the art to which the exemplary embodiments of this disclosure pertain will clearly derive and understand other effects not described herein from the following description. In other words, those skilled in the art can deduce unintended effects achieved when implementing the exemplary embodiments of this disclosure based on the exemplary embodiments of this disclosure. Attached Figure Description

[0020] Figure 1 This is a perspective view of a battery pack according to an exemplary embodiment of the present disclosure.

[0021] Figure 2 This is a perspective view of certain components of a battery pack according to exemplary embodiments of the present disclosure.

[0022] Figure 3 An enlarged perspective view showing a battery cell installed in a lower housing according to an embodiment of the present disclosure.

[0023] Figure 4 It is an exploded perspective view showing the bottom surface and a pair of side surfaces of the first battery cell stack surrounded by separators.

[0024] Figure 5 It is a perspective view showing the bottom surface and a pair of side surfaces of the first battery cell stack surrounded by separators.

[0025] Figure 6 This is a side view showing the bottom surface and a pair of side surfaces of the first battery cell stack surrounded by separators.

[0026] Figures 7 to 11 This is a conceptual diagram illustrating a method for removing a specific battery cell stack from a battery pack according to an embodiment of the present disclosure.

[0027] Figure 12 This is an exploded perspective view showing a portion of the bottom surface and a pair of side surfaces of a first battery cell stack according to another embodiment of the present disclosure, surrounded by a pair of separators.

[0028] Figure 13 This is a side view showing the bottom surface and a pair of side surfaces of the first battery cell stack surrounded by a pair of separators.

[0029] Figures 14 to 16 This is a conceptual diagram illustrating a method for removing a specific battery cell stack from a battery pack according to other embodiments of this disclosure.

[0030] Figure 17 This is an exploded perspective view showing the bottom surface and a pair of side surfaces of a first battery cell stack according to another embodiment of the present disclosure being surrounded by separator sheets.

[0031] Figure 18 and Figure 19 This is a conceptual diagram illustrating a method for removing a specific battery cell stack from a battery pack according to another embodiment of the present disclosure. Detailed Implementation

[0032] In the following, embodiments of the concepts of this disclosure will be described in detail with reference to the accompanying drawings. However, embodiments of the concepts of this disclosure may be implemented in many different forms, and therefore the scope of this disclosure should not be construed as limited to the embodiments described below. It should be understood that embodiments of the concepts of this disclosure are provided to describe the concepts of this disclosure more completely to those skilled in the art. Throughout the specification, the same reference numerals denote the same elements. Furthermore, in the drawings, various elements and regions are shown schematically. Therefore, the concepts of this disclosure are not limited to the relative dimensions of the elements or the spacing between elements shown in the drawings.

[0033] For example, the terms "first" and "second" can be used to describe individual components, but the components are not limited by the terms. These terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of this disclosure, the first component can be referred to as the second component, and similarly, the second component can be referred to as the first component.

[0034] The terminology used in this application is for describing particular embodiments only and is not intended to limit the concepts of this disclosure. As used herein, singular expressions are intended to include plural forms as well, unless the context clearly indicates otherwise. It should be understood that when the terms “comprising” and / or “including” are used herein, they specify the presence of the stated features, quantities, steps, operations, elements, components, or combinations thereof, without excluding the presence or addition of one or more features, quantities, steps, operations, elements, components, or combinations thereof.

[0035] Unless otherwise specified, all terms used herein (including technical and scientific terms) shall have the same meaning as commonly understood by one of ordinary skill in the art to which the concepts of this disclosure pertain. Furthermore, terms commonly used and defined in dictionaries shall be interpreted as having a meaning consistent with the context of the relevant art, and shall not be interpreted in an overly formal sense unless expressly defined herein.

[0036] When embodiments can be implemented in different ways, certain operations may be performed in a different order than that described below. For example, two operations described consecutively may be performed substantially simultaneously or in the reverse order of those described below.

[0037] It is anticipated that, for example, the shapes of the components shown in the accompanying drawings may vary depending on manufacturing techniques and / or tolerances. Therefore, the embodiments of this disclosure should not be construed as being limited to the specific shapes of the various regions shown in this specification, but should be understood to encompass variations in the shape of the various regions, for example, due to manufacturing processes. As used herein, the term "and / or" includes any and all combinations of more than one of the related listed items. Additionally, the term "substrate" as used herein may refer to the substrate itself or a laminate including the substrate and a predetermined layer or film formed on its surface. Furthermore, the expression "surface of substrate" as used herein should be understood to refer to the exposed surface of the substrate or the outer surface of a layer or film formed on the substrate.

[0038] (First embodiment) Figure 1 This is a perspective view of a battery pack 100 according to an exemplary embodiment of the present disclosure.

[0039] Figure 2 This is a perspective view of certain components of a battery pack 100 according to an exemplary embodiment of the present disclosure.

[0040] Figure 1 and Figure 2 The battery pack 100 is shown defined in a vertical coordinate system, which is defined by a first direction perpendicular to each other along the X-axis, a second direction along the Y-axis, and a third direction along the Z-axis. However, there are no particular restrictions on the first, second, and third directions, as long as they are perpendicular to each other.

[0041] Reference Figure 1 and Figure 2 The battery pack 100 may include a lower housing 110, individual battery cells 120, a middle beam 130, a crossbeam 116, multiple venting devices 140, multiple first embedded guides 151, multiple second embedded guides 153, gaskets 160, and an upper housing 170. The battery pack 100 is the final form of a battery system installed in a vehicle or the like.

[0042] The battery pack housing 101 corresponding to the housing of the battery pack 100 may include a lower housing 110 and an upper housing 170.

[0043] The lower housing 110 may provide an internal space 119 for mounting a plurality of battery cells 120. In some embodiments, the lower housing 110 may include a plate portion 110P and sidewalls 110S. Two directions substantially parallel to the plate portion 110P are defined as a first direction (e.g., the X-axis direction) and a second direction (e.g., the Y-axis direction), and a direction substantially perpendicular to the plate portion 110P of the lower housing 110 is defined as a third direction (e.g., the Z-axis direction). The X-axis direction, Y-axis direction, and Z-axis direction may be substantially perpendicular to each other. Unless otherwise stated, the definitions of directions will apply to the following figures.

[0044] Multiple battery cells 120 may be located on a plate portion 110P of the lower housing 110. The plate portion 110P may support the multiple battery cells 120. The plate portion 110P may include an upper surface and a lower surface that are generally parallel to each other. The upper surface of the plate portion 110P may face the multiple battery cells 120. The lower surface of the plate portion 110P is opposite to the upper surface of the plate portion 110P.

[0045] Sidewall 110S can horizontally surround multiple battery cells 120. Sidewall 110S can laterally protect multiple battery cells 120. Sidewall 110S can include: a first sidewall 111, a second sidewall 112, a third sidewall 113, and a fourth sidewall 114. The first sidewall 111, the second sidewall 112, the third sidewall 113, and the fourth sidewall 114 can be fixed to each other by, for example, friction stir welding or spot welding, but there are no particular limitations.

[0046] The first sidewall 111 and the second sidewall 112 may be substantially perpendicular to a second direction (e.g., the Y-axis direction). Each of the third sidewall 113 and the fourth sidewall 114 may be substantially perpendicular to a first direction (e.g., the X-axis direction). In some embodiments, the first sidewall 111 and the second sidewall 112 may cover the side surface of the plate portion 110P. In some embodiments, the third sidewall 113 and the fourth sidewall 114 may be located on the plate portion 110P.

[0047] In some embodiments, the first sidewall 111, second sidewall 112, third sidewall 113, and fourth sidewall 114 can be formed by an extrusion process. According to an exemplary embodiment, each of the first sidewall 111, second sidewall 112, third sidewall 113, and fourth sidewall 114 may include an internal hollow space, thus reducing the weight of the sidewall 110S. According to an exemplary embodiment, the hollow space of each of the first sidewall 111, second sidewall 112, third sidewall 113, and fourth sidewall 114 can be a gas exhaust path or a refrigerant passage.

[0048] In the following description, the technical concept of this disclosure will be described with reference to embodiments in which each of the plurality of battery cells 120 does not include a module frame. However, the above description is intended to provide non-limiting examples only and should therefore not be construed as limiting the technical concept of this disclosure in any sense. Based on the above description, those skilled in the art will be able to readily derive battery packs employing battery modules including module frames, wherein each module frame exposes one edge of a battery cell.

[0049] The intermediate beam 130 can isolate the components mounted on the lower housing 110 from each other. Therefore, the intermediate beam 130 can prevent unwanted short circuits between the multiple battery cells 120, while protecting the multiple battery cells 120.

[0050] Intermediate beam 130 may extend between third sidewall 113 and fourth sidewall 114. Intermediate beam 130 may extend in a first direction (e.g., the X-axis direction). Intermediate beam 130 may contact the third sidewall 113 and fourth sidewall 114. Intermediate beam 130 may isolate multiple battery cells 120 from each other. Intermediate beam 130 may be inserted between multiple battery cells 120. In some embodiments, intermediate beam 130 may divide the internal space 119 into two regions in a second direction (e.g., the Y-axis direction).

[0051] In some embodiments, the crossbeam 116 may be configured to divide the interior space 119 into more than two regions in a first direction (e.g., the X-axis direction). The crossbeam 116 may further isolate elements isolated by the intermediate beam 130.

[0052] Some crossbeams 116 may extend in a second direction (e.g., the Y-axis direction) between the intermediate beam 130 and the first sidewall 111. Some crossbeams 116 may extend in a second direction (e.g., the Y-axis direction) between the intermediate beam 130 and the second sidewall 112. In some embodiments, the crossbeams 116 may be configured to define a space for accommodating a stack of battery cells or a group of battery cells.

[0053] Figure 1 The arrangement of the intermediate beam 130, crossbeam 116, and multiple battery cells 120 shown is a non-limiting example and does not limit the technical concept of this disclosure in any way. Based on the above description, those skilled in the art will readily obtain battery packs including various arrangements and numbers of intermediate beams and battery cells.

[0054] Multiple venting devices 140 may be coupled to a fourth sidewall 114. The fourth sidewall 114 may include multiple vent holes connected to the multiple venting devices 140. The multiple vent holes may be configured to provide pathways for the exhaust of gas and heat from the interior of the battery pack 100.

[0055] Multiple venting devices 140 can be configured to delay heat propagation by venting high-temperature gas from the interior of the battery pack 100 to the exterior when at least one of the multiple battery cells 120 is in a thermal runaway state.

[0056] Here, the thermal runaway state of multiple battery cells 120 is a state in which the temperature change of multiple battery cells 120 accelerates the temperature change, that is, runaway positive feedback. The temperature of the multiple battery cells 120 in the thermal runaway state may rise rapidly, and may release a large amount of high-pressure gas and combustion debris.

[0057] Multiple first embedding guides 151 may be located on the sidewall 110S. Multiple first embedding guides 151 may be located at corners 110C of the upper surface of the sidewall 110S. Multiple first embedding guides 151 may engage with corners 110C of the upper surface of the sidewall 110S. Multiple first embedding guides 151 may be partially embedded in the sidewall 110S. Multiple first embedding guides 151 may protrude partially from the sidewall 110S.

[0058] Multiple second embedded guide portions 153 may be located on the sidewall 110S. Multiple second embedded guide portions 153 may be located on the upper surface of the sidewall 110S. Multiple second embedded guide portions 153 may be inserted between the corner portions 110C of the sidewall 110S. Multiple second embedded guide portions 153 may be inserted between multiple first embedded guide portions 151. Multiple second embedded guide portions 153 may engage with the upper surface of the sidewall 110S. Multiple second embedded guide portions 153 may be partially embedded in the sidewall 110S. Multiple second embedded guide portions 153 may partially protrude from the sidewall 110S.

[0059] Each of the first embedded guide portion 151 and the second embedded guide portion 153 may contain a metallic material. For example, each of the first embedded guide portion 151 and the second embedded guide portion 153 may contain aluminum. For example, each of the first embedded guide portion 151 and the second embedded guide portion 153 may contain steel such as carbon steel, nickel steel, chromium steel, nickel-chromium steel, or manganese steel.

[0060] The battery pack 100 may further include electronic components. In some embodiments, the electronic components may be mounted on the lower housing 110. In some embodiments, the electronic components may be disposed between the fourth sidewall 114 on which the venting device 140 is mounted and the plurality of battery cells 120. In some embodiments, the electronic components may include electronic devices required to drive the battery pack 100.

[0061] In some embodiments, for example, the electronic components may include a battery management system (BMS). The BMS may be configured to monitor, balance, and control the battery pack 100. In some embodiments, monitoring of the battery pack 100 may include measuring the voltage and current of a specific battery cell 120 among a plurality of battery cells 120 and measuring the temperature at a set location within the battery pack 100. In some embodiments, the battery pack 100 may include measuring devices for measuring the voltage, current, and temperature as described above.

[0062] Balancing the battery pack 100 is an operation to reduce the deviation between the multiple battery cells 120. Control of the battery pack 100 includes prevention of overcharging, over-discharging, and overcurrent. Through monitoring, balancing, and control, the battery pack 100 can operate under optimal conditions, thereby preventing a reduction or shortening of the lifespan of each of the multiple battery cells 120.

[0063] Electronic components may also include: cooling devices, power relay assemblies (PRAs), safety plugs, etc. Cooling devices may include cooling fans. Cooling fans circulate air within the battery pack 100 to prevent overheating of each of the multiple battery cells 120. The PRA can be configured to supply power from the high-voltage battery to an external load (e.g., a vehicle's electric motor) or to disconnect power. In the event of an abnormal voltage, such as a voltage surge, the PRA can disconnect power to the external load (e.g., the vehicle's electric motor) to protect both the multiple battery cells 120 and the external load (e.g., the vehicle's electric motor).

[0064] The battery pack 100 may further include a plurality of busbars configured to be electrically connected to a plurality of battery cells 120. The plurality of battery cells 120 may be connected in series and / or in parallel via the plurality of busbars. Therefore, the battery pack 100 may be configured to output high voltage to an external load (e.g., a vehicle's electric motor).

[0065] Gasket 160 may comprise a material that is elastic in response to pressure applied thereto. Gasket 160 may comprise rubber synthesized from materials such as ethylene-propylene diene monomer (EPDM). When the lower housing 110 and the upper housing 170 are joined together, gasket 160 may be inserted between the lower housing 110 and the upper housing 170. The lower housing 110 and the upper housing 170 may press gasket 160 to deform it to a certain extent. Therefore, the battery pack 100 can be sealed, and the internal space of the battery pack 100 can be isolated from external fluids.

[0066] The upper housing 170 may be combined with the lower housing 110. In some embodiments, the upper housing 170 may include a main surface and an edge portion. The main surface may cover components mounted on the battery pack 100, such as multiple battery cells 120 and electronic components. The edge portion is the surface that contacts the lower housing 110. In some embodiments, the upper housing 170 may be flat, and in this case, the edge portion may horizontally surround the main surface. In some embodiments, the main surface may rise relative to the edge portion, and the edge portion and the main surface may be connected by a bend.

[0067] In some embodiments, the upper housing 170 can be coupled to the sidewall 110S of the lower housing 110 via a first embedded guide 151 and a second embedded guide 153. According to an exemplary embodiment, the battery pack 100 may further include elements coupled to the first embedded guide 151 and the second embedded guide 153 to secure the upper housing 170 to the sidewall 110S of the lower housing 110. These elements may include, but are not limited to, bolts and nuts.

[0068] Figure 3 An enlarged perspective view showing a battery cell 120 installed in a lower housing according to an embodiment of the present disclosure.

[0069] Reference Figure 3 Battery cell stacks S1, S2, ..., S6 are disposed in respective regions defined by each of the side walls 111, 112, 113, and 114 of the lower housing 110, the intermediate beam 130, and the crossbeam 116. Each of the battery cell stacks S1, S2, ..., S6 comprises a plurality of battery cells 120. In the following text, the term "battery cell stack" may be understood simply as an assembly in which a group or plurality of battery cells are housed within a particular frame.

[0070] In some embodiments, the battery cell 120 may be a pouch cell, but this disclosure is not limited thereto. In some embodiments, the battery cell 120 may be a prismatic cell.

[0071] In some embodiments, the battery cell 120 includes a thin plate-shaped body, preferably having the structure of a pouch-type battery cell. The pouch-type battery cell can have a structure in which a positive electrode, a separator, and a negative electrode are alternately stacked to form an electrode assembly, and electrode tabs are pulled out from at least one side of the electrode assembly and connected to battery cell leads. The positive and negative electrodes can be prepared by coating at least one surface of the current collector with a slurry containing, for example, an electrode active material, a binder resin, a conductive agent, or other additives. As electrode active materials, in the case of the positive electrode, conventional positive electrode active materials, such as transition metal oxides containing lithium, can be used, and in the case of the negative electrode, conventional negative electrode active materials that absorb and release lithium ions, such as lithium metal, carbon materials, metal compounds, or mixtures thereof, can be used. Conventional porous polymer membranes used in lithium secondary batteries can be employed as the separator.

[0072] Electrolytes used in conventional lithium-ion batteries can be used as the electrolyte contained in the cover along with the electrode assembly. The cover is formed of a sheet material and includes a receiving portion for accommodating the electrode assembly. Preferably, the cover is formed by combining a first shell and a second shell formed by processing the sheet material into a specific shape. The sheet material of the cover has a multilayer structure in which an outermost resin layer formed of an insulating material such as polyethylene terephthalate (PET) or nylon, a metal layer formed of aluminum to maintain mechanical strength and prevent the penetration of moisture and oxygen, and an inner resin layer formed of a polyolefin-based material with thermal adhesion, thus serving as a sealing material, are stacked.

[0073] In the sheet material of the cover, an adhesive resin layer may be inserted between the inner resin layer and the metal layer, and between the outermost resin layer and the metal layer, as needed. The adhesive resin layer is formed as a single layer or multiple layers for smooth bonding between different types of materials, and as the material for the adhesive resin layer, polyolefin-based resins can typically be used, polyurethane resins can be used for smooth processing, or mixtures thereof can be used.

[0074] Multiple battery cells 120 may be arranged in a first direction (e.g., the X-axis direction). In some embodiments, a first battery cell stack S1, a second battery cell stack S2, and a third battery cell stack S3 may be arranged in the first direction (e.g., the X-axis direction). In some embodiments, a fourth battery cell stack S4, a fifth battery cell stack S5, and a sixth battery cell stack S6 may be arranged in the first direction (e.g., the X-axis direction).

[0075] In some embodiments, the first battery cell stack S1 and the fourth battery cell stack S4 may be arranged in a second direction (e.g., the Y-axis direction). In some embodiments, the second battery cell stack S2 and the fifth battery cell stack S5 may be arranged in a second direction (e.g., the Y-axis direction). In some embodiments, the third battery cell stack S3 and the sixth battery cell stack S6 may be arranged in a second direction (e.g., the Y-axis direction).

[0076] Each of the battery cell stacks S1, S2, ..., S6 is provided with a corresponding separator 184. The separator 184 may surround the bottom surface and a pair of side surfaces of each of the battery cell stacks S1, S2, ..., S6 without interrupting the electrical connection of the battery cells 120. In some embodiments, the separator 184 may face the bottom surface of the battery cell stacks S1, S2, ..., S6.

[0077] The separator 184 may extend horizontally on all or part of the bottom surface of the battery cell stacks S1, S2, ... and S6, and generally vertically along the side surfaces of the battery cell stacks S1, S2, ... and S6.

[0078] In some embodiments, the separator 184 may extend along a first direction (e.g., the X-axis direction) and / or a second direction (e.g., the Y-axis direction) on the bottom surface of the battery cell stacks S1, S2, ... and S6, be folded at the side ends of the battery cell stacks S1, S2, ... and S6, and then extend along the side surfaces of the battery cell stacks S1, S2, ... and S6.

[0079] In some embodiments, the separator 184 may include two separators extending from near the opposite ends of the bottom surfaces of the battery cell stacks S1, S2, ..., S6 along a first direction (X-axis direction) and / or a second direction (e.g., Y-axis direction), and extending along the side surfaces of the battery cell stacks S1, S2, ..., S6. Reference will be made below. Figure 12 and Figure 13 Describe the configuration in more detail.

[0080] Figure 4 This is an exploded perspective view showing the bottom surface and a pair of side surfaces of the first battery cell stack S1 surrounded by separators 184. Figure 5 This is a perspective view showing the bottom surface and a pair of side surfaces of the first battery cell stack S1 surrounded by separators 184. Here, separators 184 are shown surrounding the first battery cell stack S1, but those skilled in the art will understand that the second battery cell stack S2, the third battery cell stack S3, the fourth battery cell stack S4, the fifth battery cell stack S5, and the sixth battery cell stack S6 can also be configured similarly.

[0081] Reference Figure 4 and Figure 5 The bottom surface of the first battery cell stack S1, which includes battery cells 120 stacked in a first direction (e.g., the X-axis direction), and a pair of side surfaces perpendicular to the first direction (e.g., the X-axis direction), can face the separator 184.

[0082] The material of the separator 184 may be polyethylene terephthalate, polyvinyl chloride, polystyrene, polyethylene, polyethylene naphthalate, polybutylene terephthalate, polyacetal, polyamide, polyester sulfone, polyphenylene ether, polyphenylene sulfide, polypropylene, or copolymers thereof. However, this disclosure is not limited thereto.

[0083] At least one surface of the separator 184 may be adhesive. In some embodiments, the separator 184 may be configured such that its adhesive surface faces the battery pack housing 101. In some embodiments, the separator 184 may be configured such that its adhesive surface faces the lower housing 110. In some embodiments, the separator 184 may be configured such that its adhesive surface faces the plate portion 110P of the lower housing 110. When the separator 184 contacts the plate portion 110P, the separator 184 may adhere to the plate portion 110P due to its adhesiveness. In some embodiments, both surfaces of the separator 184 may be adhesive.

[0084] The release liner 184 may include an adhesive layer to provide adhesion to the release liner 184. The adhesive layer may be any material known in the art, such as, but not limited to, acrylic adhesive compositions, epoxy adhesive compositions, polyolefin adhesive compositions, polyamide adhesive compositions, polyurethane adhesive compositions, EVA adhesive compositions, etc.

[0085] A thermally conductive resin layer 182 may be disposed between the separator 184 and the bottom surface of the first battery cell stack S1. The thermally conductive resin layer 182 may comprise a thermally conductive resin, and more specifically, a thermally conductive adhesive material. In some embodiments, the thermally conductive resin may comprise at least one of a silicone-based resin, a urethane-based resin, or an acrylic resin. However, this disclosure is not limited thereto, and any thermally conductive resin known in the art to which this disclosure pertains may be used.

[0086] The thermally conductive resin is liquid when applied, but it can be cured to fix the separator 184 to the first battery cell stack S1. The thermally conductive resin has excellent thermal conductivity, thus rapidly transferring the heat generated in the battery cell 120 to the plate portion 110P, thereby preventing overheating of the battery pack 100.

[0087] In some embodiments, the width W2 of the separator 184 in the second direction (e.g., the Y-axis direction) may be smaller than the width W1 of the first battery cell stack S1. The width W3 of the thermally conductive resin layer 182 in the second direction (e.g., the Y-axis direction) may be less than or equal to the width W2 of the separator 184 in the second direction (e.g., the Y-axis direction).

[0088] Since the width W3 of the thermally conductive resin layer 182 in the second direction (e.g., the Y-axis direction) is less than or equal to the width W2 of the separator 184 in the second direction (e.g., the Y-axis direction), the thermally conductive resin layer 182 can be disposed only between the first battery cell stack S1 and the separator 184. In other words, the thermally conductive resin layer 182 can be configured not to contact the battery pack housing 101. In some embodiments, one surface of the thermally conductive resin layer 182 can contact the separator 184, and its other surface can contact the bottom surface of the battery cell stack S1.

[0089] In some embodiments, when the separator 184 is unfolded in a third direction (e.g., the Z-axis direction), the height h2 of the separator 184 in that third direction (e.g., the Z-axis direction) can be greater than the height h1 of the first battery cell stack S1. Therefore, as shown, the upper end of the separator 184 can extend above the upper surface of each of the battery cell stacks S1, S2, ..., S6. However, the separator 184 is formed of a flexible material, so its upper end in the battery pack 100 can be folded parallel to the upper surfaces of the battery cell stacks S1, S2, ..., S6.

[0090] Figure 6 This is a side view showing the bottom surface and a pair of side surfaces of the first battery cell stack S1 surrounded by separators 184.

[0091] Reference Figure 6 The bottom surface of the first battery cell stack S1 corresponds to one edge of each battery cell 120 included in the first battery cell stack S1. The bottom surface of the first battery cell stack S1 faces the separator 184, and the thermally conductive resin layer 182 is inserted therebetween.

[0092] The separator 184 can be bonded to the thermally conductive resin layer 182 with a first adhesive strength per unit area. The thermally conductive resin layer 182 does not contact the battery pack housing 101, and when the thermally conductive resin layer 182 is bonded to the battery pack housing 101, particularly to the plate portion 110P which is the bottom surface of the lower housing 110, the second adhesive strength per unit area formed between the thermally conductive resin layer 182 and the battery pack housing 101 is greater than the first adhesive strength. In other words, the first adhesive strength is less than the second adhesive strength generated in the hypothetical case (i.e., the case where the thermally conductive resin layer 182 is bonded to the plate portion 110P which is the bottom surface of the lower housing 110).

[0093] In some embodiments, the initial bond strength, when measured according to ASTM D3163, can be approximately 15 gf / mm². 2 Up to approximately 65 gf / mm 2 Within a certain range. In some embodiments, the second bond strength can be approximately 30 gf / mm² when measured according to ASTM D3163. 2 Up to approximately 90 gf / mm 2 Within the specified range. When the initial adhesive strength is too high, it may be difficult to remove the separator 184 when needed. When the initial adhesive strength is too low, the battery cell 120 is not sufficiently secured to the battery pack 100, and the battery cell leads may be damaged.

[0094] In some embodiments, the first adhesive strength can be from about 10% to about 70% of the second adhesive strength. In some embodiments, the first adhesive strength can be in the range of about 10% to about 70%, about 15% to about 65%, about 20% to about 60%, about 25% to about 55%, about 30% to about 50%, about 35% to about 45%, or between two of these values.

[0095] For example, bond strength can be measured using methods such as ASTM D950, ASTM D1876, ASTM D3163, ASTM D1002, ASTM D5868, ASTM D4541, ASTM D2295, ASTM D7234, ISO 1345, or ISO 4624.

[0096] like Figure 6 As shown, the separator 184 can extend along a first direction (e.g., the X-axis direction) on the bottom surface of the first battery cell stack S1. Subsequently, the separator 184 can be folded at a side end of the first battery cell stack S1 and then extended along the side surface of the first battery cell stack S1. In some embodiments, the separator 184 can extend from a side end of the first battery cell stack S1 along the side surface of the first battery cell stack S1 in a third direction (e.g., the Z-axis direction).

[0097] Figures 4 to 6 The thermally conductive resin layer 182 is shown to be a continuous layer, but the thermally conductive resin layer 182 may be a discontinuous layer in the horizontal direction.

[0098] Figures 7 to 11 This is a conceptual diagram illustrating a method for removing a specific stack of battery cells from a battery pack 100 according to an embodiment of the present disclosure. The description will be based on a first stack of battery cells S1. Figures 7 to 11This method is applicable to other cell stacks S1, S2, ... and S6, but it will be obvious to those skilled in the art that this method can also be applied to other cell stacks S1, S2, ... and S6.

[0099] Reference Figure 7 The first battery cell stack S1 is located between the crossbeam 116 and the fourth sidewall 114, and the separator 184 and the thermally conductive resin layer 182 are referenced. Figures 4 to 6 Configure as described above.

[0100] The spacer 184 can be configured to be attached to and detached from the crossbeam 116 and the fourth sidewall 114. As described above, at least one surface of the spacer 184 can be provided with an adhesive layer, and the spacer 184 can be configured such that the adhesive layer faces the plate portion 110P of the lower housing. The adhesive layer can also be attached to and detached from the crossbeam 116 and the fourth sidewall 114 by applying force to the end of the spacer 184 in an appropriate direction.

[0101] Reference Figure 8 A force F is applied to the end of the separator 184 in a direction away from the plate portion 110P. The force F is transmitted to the separator 184 attached to the bottom of the first battery cell stack S1, thus generating a certain shear force in the horizontal direction (i.e., the direction perpendicular to the third direction (e.g., the Z-axis direction)).

[0102] Reference Figure 9 When a force F is continuously applied, the shear force gradually increases, and when the shear force exceeds a certain critical point, the separator 184 overcomes the adhesive strength relative to the thermally conductive resin layer 182 and the adhesive strength relative to the plate portion 110P, and begins to be pulled out to one side. That is, the separator 184 begins to be pulled out in the direction of the shear force generated by the force F applied to the end of the separator 184 (here, the X-axis direction).

[0103] Reference Figure 10 Once the separator 184 begins to be pulled out, it can be continuously pulled out due to the force F applied to it, and eventually it can be completely removed from the surface of the first cell stack S1.

[0104] Reference Figure 11 Since the plate portion 110P and the thermally conductive resin layer 182 are spaced apart from each other, the first battery cell stack S1 can be easily removed from the lower housing 170.

[0105] (Second Embodiment) Figure 12This is an exploded perspective view showing a portion of the bottom surface and a pair of side surfaces of a first battery cell stack S1 according to another embodiment of the present disclosure, surrounded by a pair of separators 184a and 184b. Figure 13 This is a side view showing the bottom surface and a pair of side surfaces of the first battery cell stack S1 surrounded by a pair of separators 184a and 184b.

[0106] Reference Figure 12 and Figure 13 In this embodiment, a pair of isolation plates are provided, namely, a first isolation plate 184a and a second isolation plate 184b, while... Figure 4 In one embodiment, an isolation sheet 184 is provided.

[0107] The first separator 184a may extend along the side surface of the first battery cell stack S1. The first separator 184a may extend over at least the entire height of the first battery cell stack S1. Subsequently, the first separator 184a may be folded from the lower end of one side surface of the first battery cell stack S1 and then extended a certain length toward the center of the bottom surface of the first battery cell stack S1.

[0108] A first thermally conductive resin layer 182a may be disposed between the bottom surface of the first battery cell stack S1 and the first separator 184a. In some embodiments, the first thermally conductive resin layer 182a may be disposed only between the bottom surface of the first battery cell stack S1 and the first separator 184a.

[0109] The second separator 184b may extend along another side surface of the first battery cell stack S1. This other side surface is opposite to the first side surface. The second separator 184b may extend over at least the entire height of the first battery cell stack S1. Subsequently, the second separator 184b may be folded from the lower end of the other side surface of the first battery cell stack S1 and then extended a specific length toward the center of the bottom surface of the first battery cell stack S1.

[0110] A second thermally conductive resin layer 182b may be disposed between the bottom surface of the first battery cell stack S1 and the second separator 184b. In some embodiments, the second thermally conductive resin layer 182b may be disposed only between the bottom surface of the first battery cell stack S1 and the second separator 184b.

[0111] In some embodiments, a thermally conductive resin layer may not be provided between the first separator 184a and the second separator 184b. In this case, the bottom surface of the first battery cell stack S1 between the first separator 184a and the second separator 184b can directly face the plate portion 110P (see...). Figure 2 ).

[0112] Figures 14 to 16This is a conceptual diagram illustrating a method for removing a specific stack of battery cells from a battery pack 100 according to another embodiment of this disclosure. The description will be based on a first stack of battery cells S1. Figures 14 to 16 This method is applicable to other cell stacks S1, S2, ... and S6, but it will be obvious to those skilled in the art that this method can also be applied to other cell stacks S1, S2, ... and S6.

[0113] Reference Figure 14 The first battery cell stack S1 is located between the crossbeam 116 and the fourth sidewall 114, and the first separator 184a and the second separator 184b, as well as the first thermally conductive resin layer 182a and the second thermally conductive resin layer 182b, are referenced. Figure 12 and Figure 13 Configure as described above.

[0114] Each of the first spacer 184a and the second spacer 184b may be configured to be attached to and detached from the fourth sidewall 114 and the crossbeam 116. Each of the first spacer 184a and the second spacer 184b may include an adhesive layer on at least one surface, and is configured such that the adhesive layer faces the plate portion 110P of the lower housing. The adhesive layer may be attached to the fourth sidewall 114 and the crossbeam 116, and may be detached from the fourth sidewall 114 and the crossbeam 116 by applying force to the ends of the first spacer 184a and the second spacer 184b in an appropriate direction.

[0115] Reference Figure 15 A force F is applied to the ends of the first separator 184a and the second separator 184b in a direction away from the plate portion 110P. The force F is transmitted to the first separator 184a and the second separator 184b disposed between the bottom of the first battery cell stack S1 and the plate portion 110P, thus generating a certain shear force in the horizontal direction (i.e., the direction perpendicular to the third direction (e.g., the Z-axis direction)).

[0116] When a force F is continuously applied, the shear force gradually increases, and when the shear force exceeds a certain critical point, the first insulating sheet 184a and the second insulating sheet 184b overcome the adhesive strength relative to the first thermally conductive resin layer 182a and the second thermally conductive resin layer 182b and the adhesive strength relative to the plate portion 110P, and begin to be pulled out to one side. That is, the first insulating sheet 184a and the second insulating sheet 184b begin to be pulled out in the direction of the shear force generated by the force F applied to one end of each of the first insulating sheet 184a and the second insulating sheet 184b.

[0117] Reference Figure 16The first and second separators 184a and 184b, which are initially pulled out, can be continuously pulled out by the force F applied to them, and eventually removed from the space between the bottom of the first cell stack S1 and the plate 110P.

[0118] The first thermally conductive resin layer 182a and the second thermally conductive resin layer 182b are spaced apart from the plate portion 110P by a distance substantially corresponding to the thickness of the first separator 184a and the second separator 184b. Therefore, the first battery cell stack S1 or a specific battery cell 120 can be relatively easily removed from the lower housing 110. In the battery pack 100 according to an embodiment of the present disclosure, when a specific battery cell 120 is defective, only the defective battery cell 120 can be selected and easily replaced with another battery cell, thus greatly improving the convenience of maintenance.

[0119] (Third embodiment) Figure 17 This is an exploded perspective view showing the bottom surface and a pair of side surfaces of a first battery cell stack S1 according to another embodiment of the present disclosure being surrounded by separator sheets 184.

[0120] Figure 17 The embodiments are the same as those mentioned above. Figures 4 to 11 The described embodiment differs in that a cutting line 185 is formed on the separator 184. Therefore, this embodiment will focus on the differences.

[0121] In some embodiments, the cutting line 185 may include slits that pass through the spacer 184 at intervals in a linear direction. In some embodiments, the cutting line 185 may include intermittent or continuous slits formed to a certain depth without passing through the spacer 184.

[0122] When a shearing force is applied in a direction perpendicular to or diagonally to the cut line 185, the cut line 185 helps the separator 184 to break easily. Specifically, the separator 184 can break along the cut line 185. Because the separator 184 breaks along the cut line 185, the predictability of the breakage location on the separator 184 can be increased, and a force F can be applied to both ends of the separator 184 to remove the separator 184 more quickly, as described above. Figures 12 to 16 The described embodiments are similar.

[0123] Thermally conductive resin layers 182a and 182b may be disposed between the bottom surface of the first battery cell stack S1 and the separator 184. In some embodiments, a first thermally conductive resin layer 182a may be disposed on one side of the cutting line 185, and a second thermally conductive resin layer 182b may be disposed on the other side of the cutting line 185. In some embodiments, no thermally conductive resin layer may be disposed between the bottom surface of the first battery cell stack S1 and the cutting line 185.

[0124] Figure 18 and Figure 19 This is a conceptual diagram illustrating a method for removing a specific battery cell stack from a battery pack 100 according to another embodiment of the present disclosure.

[0125] Reference Figure 17 and Figure 18 When a force F is applied to the opposite end of the separator 184, a horizontal shear force is applied to the separator 184 between the bottom of the first battery cell stack S1 and the plate portion 110P. Then, when the force F is continuously applied, the shear force can overcome the adhesive strength relative to the first thermally conductive resin layer 182a and the second thermally conductive resin layer 182b, overcome the adhesive strength relative to the plate portion 110P, and overcome the fracture strength of the separator 184 at the cut line 185. Then, the separator 184 breaks along the cut line 185 into a first separator 184a and a second separator 184b, and the first separator 184a and the second separator 184b are pulled out along the bottom surface of the first battery cell stack S1.

[0126] Reference Figure 19 When a force F is continuously applied to the ends of the first separator 184a and the second separator 184b, the first separator 184a and the second separator 184b can be continuously pulled out, so that the separator 184 can eventually be removed from the space between the bottom of the first battery cell stack S1 and the plate portion 110P.

[0127] The first thermally conductive resin layer 182a and the second thermally conductive resin layer 182b are spaced apart from the plate portion 110P by a distance substantially corresponding to the thickness of the separator 184, so that the first battery cell stack S1 or a specific battery cell 120 can be relatively easily removed from the lower housing 110. In the battery pack 100 according to an embodiment of the present disclosure, when a specific battery cell 120 is defective, only the defective battery cell 120 can be selected and easily replaced with another battery cell, thus greatly improving the convenience of maintenance.

[0128] Although embodiments of the present disclosure have been described in detail above, those skilled in the art can implement the present disclosure in many different forms without departing from the spirit and scope of the present disclosure as defined in the appended claims. Therefore, it should be understood that all modifications to the embodiments of the present disclosure fall within the scope of the present disclosure.

Claims

1. A battery pack, comprising: A battery pack housing, the battery pack housing comprising a lower housing and an upper housing defining an internal space; Multiple battery cells, wherein the multiple battery cells are located in the internal space; A separator is located between the bottom surface of the battery pack housing and the plurality of battery cells; as well as A thermally conductive resin layer is located between the separator and the plurality of battery cells. The insulating sheet is bonded to the thermally conductive resin layer with a first adhesive strength per unit area, and The first adhesive strength is lower than the second adhesive strength per unit area between the battery pack housing and the thermally conductive resin layer when the battery pack housing and the thermally conductive resin layer are bonded to each other.

2. The battery pack according to claim 1, wherein, The first adhesive strength is in the range of about 10% to about 70% of the second adhesive strength.

3. The battery pack according to claim 1, wherein, The thermally conductive resin layer is disposed only between the separator and the plurality of battery cells.

4. The battery pack according to claim 3, wherein, The thermally conductive resin layer does not contact the battery pack casing.

5. The battery pack according to claim 1, wherein, The separator has adhesive strength relative to the battery pack housing.

6. The battery pack according to claim 1, wherein, The plurality of battery cells includes at least one battery cell stack. The surface of the at least one battery cell stack facing the bottom surface faces the separator, and The width of the separator is smaller than the width of the surface of the at least one battery cell stack.

7. The battery pack according to claim 6, wherein, The separator extends along the side surface of the at least one battery cell stack.

8. The battery pack according to claim 6, wherein, The isolation sheet includes a cut line that runs through the isolation sheet. The cutting line passes between the at least one battery cell stack and the bottom surface.

9. The battery pack according to claim 6, wherein, The thermally conductive resin layer is disposed only between the surface of the at least one battery cell stack facing the bottom surface and the separator.

10. The battery pack according to claim 9, wherein, One surface of the thermally conductive resin layer is in contact with the separator, and the other surface of the thermally conductive resin layer is in contact with the surface of the at least one battery cell stack.

11. The battery pack according to claim 1, wherein, The plurality of battery cells includes at least one battery cell stack, and The isolation sheet includes a first isolation sheet and a second isolation sheet. Wherein, the first separator is located at the end of the at least one battery cell stack between the at least one battery cell stack and the bottom surface, and The second separator is spaced apart from the first separator and is located at the other end of the at least one battery cell stack between the at least one battery cell stack and the bottom surface.

12. The battery pack according to claim 11, wherein, Between the first separator and the second separator, the at least one battery cell stack directly faces the bottom surface.

13. A battery pack, comprising: Multiple battery cells are stacked in the first direction in a vertical coordinate system defined by a first direction, a second direction, and a third direction that are perpendicular to each other. A battery pack housing, the battery pack housing including a lower housing and an upper housing, the lower housing and the upper housing defining an internal space for accommodating the plurality of battery cells; A separator is located between the bottom surface of the battery pack housing and the plurality of battery cells; as well as A thermally conductive resin layer is located between the separator and the plurality of battery cells. The insulating sheet is configured to separate from the thermally conductive resin layer when a shear force is applied to the thermally conductive resin layer.

14. The battery pack according to claim 13, wherein, The thermally conductive resin layer does not contact the battery pack casing.

15. The battery pack according to claim 14, wherein, The lower housing includes side walls and a crossbeam that passes through the lower housing, and The isolation plate is configured to be attached to at least one of the sidewall and the crossbeam, and to be detachable from at least one of the sidewall and the crossbeam.

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