Battery pack

Abstract

A battery pack, the battery pack comprising: a battery cell assembly, the battery cell assembly comprising a cell block having a plurality of battery cells and a bottom cover plate below a bottom surface of the cell block; the shell is provided with an opening and accommodates the battery cell assembly; the battery cell assembly is provided with an opening, the battery pack cover is connected to the shell and covers the opening, the battery cell assembly and the bottom wall of the shell are separated from each other to form a first space, and the bottom cover plate comprises an exhaust channel communicated with the first space.

Description

Technical Field

[0001] The present disclosure relates to a battery pack. Background Art

[0002] Unlike primary batteries, secondary batteries can be charged and discharged multiple times. Secondary batteries are widely used as energy sources for various wireless devices (such as mobile phones, laptops, and cordless vacuum cleaners). In recent years, as the manufacturing cost per unit capacity of secondary batteries has been significantly reduced due to increased energy density and economies of scale, and the cruising range of battery electric vehicles (BEVs) has increased to a level equal to that of fuel vehicles, the main use of secondary batteries has shifted from mobile devices to vehicles.

[0003] Since secondary batteries are used in vehicles, the demand for the safety of secondary batteries is growing. When an accident such as a fire occurs in a secondary battery used in a vehicle, the driver's life is endangered, so it is necessary to conduct research on technologies to improve the safety of secondary batteries. The background description provided herein is for the purpose of generally introducing the context of the present disclosure. Unless otherwise specified herein, the materials described in this section are not prior art to the claims in this application, and are not admitted to be prior art or suggestions of prior art by being included in this section. Summary of the invention

[0004] Technical issues

[0005] The present disclosure is directed to providing a battery pack with improved safety.

[0006] This and other objects and advantages of the present disclosure can be understood from the following detailed description and will become more fully apparent from the exemplary embodiments of the present disclosure. Moreover, it will be easily understood that the objects and advantages of the present disclosure can be achieved by the means shown in the appended claims and their combinations.

[0007] Technical Solution

[0008] According to the technical concept of the present disclosure, in order to achieve the above-mentioned purpose, a battery pack is provided, which includes: a battery cell assembly, the battery cell assembly including a cell block having a plurality of battery cells and a bottom cover plate below the bottom surface of the cell block; an outer shell, the outer shell having an opening and accommodating the battery cell assembly; and a battery pack cover, the battery pack cover is connected to the outer shell and covers the opening, wherein the battery cell assembly and the bottom wall of the outer shell are spaced apart from each other to form a first space, and wherein the bottom cover plate includes an exhaust channel connected to the first space.

[0009] In an exemplary embodiment, the bottom cover plate may further include: a protruding extension portion protruding toward the first space and extending in a first direction along the bottom surface of the cell block, wherein the exhaust passage may include a portion extending in the first direction in the protruding extension portion.

[0010] In an exemplary embodiment, the bottom cover plate may also include: a main board, the main board facing the bottom surface of the battery block; and a protruding extension, the protruding extension extending in a first direction along the bottom surface of the battery block below the main board, wherein the exhaust channel may include: a first exhaust channel vertically passing through the main board; and a second exhaust channel, the second exhaust channel extending along the first direction in the protruding extension and having an inlet connected to the first exhaust channel and an outlet connected to the first space.

[0011] In an exemplary embodiment, the first exhaust passage may extend in a vertical direction, and wherein the second exhaust passage may extend in a horizontal direction.

[0012] In an exemplary embodiment, the battery cell assembly may further include: a top cover plate on a top surface of the cell block, wherein the top cover plate may include a first cooling passage configured to allow a first cooling fluid to flow therethrough.

[0013] In an exemplary embodiment, the battery cell assembly may further include: a first thermally conductive adhesive layer between the top cover plate and the cell block.

[0014] In an exemplary embodiment, the battery cell assembly may be coupled to the battery pack cover.

[0015] In an exemplary embodiment, the battery pack cover may include a second cooling passage configured to allow a second cooling fluid to flow therethrough.

[0016] In an exemplary embodiment, the battery pack may further include: a second thermally conductive adhesive layer between the battery cell assembly and the battery pack cover.

[0017] In an exemplary embodiment, the battery cell assembly may further include: a side cover plate on at least one side of the cell block, and wherein the side cover plate may be fastened to the housing.

[0018] In an exemplary embodiment, the battery cell assembly may further include side cover plates spaced apart from each other. The cell block may be disposed between the side cover plates. The side cover plates may be fastened to different support blocks disposed in the housing.

[0019] In an exemplary embodiment, a sealed portion of a pouch in the pouch type battery cell may face the first space.

[0020] In an exemplary embodiment, each of the plurality of battery cells may be a cylindrical battery cell or a prismatic battery cell and include a vent.

[0021] In an exemplary embodiment, the vent portion of the cylindrical type battery cell or the prismatic type battery cell may face the first space.

[0022] In an exemplary embodiment, the present disclosure provides an electric mobile device including a battery pack, the battery pack including: a battery cell assembly, the battery cell assembly including a cell block having a plurality of battery cells and a bottom cover plate below the bottom surface of the cell block; a shell having an opening and accommodating the battery cell assembly; and a battery pack cover, the battery pack cover being connected to the shell and covering the opening, wherein the battery cell assembly and a bottom wall of the shell are spaced apart from each other to form a first space, and wherein the bottom cover plate includes an exhaust channel connected to the first space.

[0023] In an exemplary embodiment, the electric mobility device may be an electric vehicle.

[0024] In an exemplary embodiment, the battery pack may further include: a discharge portion communicating with the first space.

[0025] In an exemplary embodiment, the discharge portion may be located at a side of the housing facing a rear side of the electric moving device.

[0026] In an exemplary embodiment, the present disclosure provides a battery pack, comprising: a battery cell assembly, the battery cell assembly comprising a cell block having a plurality of battery cells, a top cover plate on a top surface of the cell block, a bottom cover plate below a bottom surface of the cell block, a side cover plate on at least one side of the cell block, and a first thermally conductive adhesive layer between the top cover plate and the cell block; a housing having an opening and accommodating the battery cell assembly; a battery pack cover, the battery pack cover being coupled to the housing and covering the opening; and a second thermally conductive adhesive layer, the second thermally conductive adhesive layer being located between the battery cell assembly and the battery pack cover, wherein the battery cell assembly and a bottom wall of the housing are spaced apart from each other to form a first space, wherein the bottom cover plate comprises an exhaust channel communicating with the first space, wherein the top cover plate comprises a first cooling passage, the first cooling passage being configured to allow a first cooling fluid to flow therethrough, and wherein the battery pack cover comprises a second cooling passage, the second cooling passage being configured to allow a second cooling fluid to flow therethrough.

[0027] In an exemplary embodiment, the battery pack may further include: a discharge portion communicating with the first space.

[0028] According to an exemplary embodiment of the present disclosure, a free volume (first space) serving as a buffer for external impact is provided between the bottom of the battery pack and the battery cell assembly, thereby preventing damage to the battery cell assembly and / or the battery cell due to external impact and ultimately improving the safety of the battery pack.

[0029] In addition, according to an exemplary embodiment of the present disclosure, the exhaust channel provided in the free volume and the bottom cover plate of the battery cell assembly forms a directional exhaust channel of the battery pack, so that high-temperature gas or flame in the battery pack can be discharged to the outside of the battery pack via the directional exhaust channel. Therefore, passengers can be protected in the event of a thermal runaway event, thereby improving the safety of the battery pack.

[0030] Furthermore, even when the bottom wall of the battery pack case is deformed by an external impact beyond the height of the free volume provided in the battery pack case, the protruding extension of the bottom cover plate can serve as a protective member for protecting the cell blocks, thereby improving the safety of the battery pack.

[0031] The effects obtained in the exemplary embodiments of the present disclosure are not limited to the above effects, and those skilled in the art to which the exemplary embodiments of the present disclosure belong can clearly derive and understand other effects not mentioned above from the following description. That is, those skilled in the art can also derive unexpected effects of implementing the exemplary embodiments of the present disclosure according to the exemplary embodiments of the present disclosure.

[0032] Beneficial Effects

[0033] According to an exemplary embodiment, since a free volume serving as a buffer for external impact is provided between the bottom of the battery pack and the battery cell assembly, damage to the battery cell assembly and / or the battery cell due to external impact can be prevented and ultimately the safety of the battery pack can be improved.

[0034] In addition, according to the exemplary embodiment, the free volume and the exhaust channel provided in the bottom cover plate of the battery cell assembly together form a directional exhaust channel in the battery pack, and the high-temperature gas or flame in the battery pack can be discharged to the outside of the battery pack via the directional exhaust channel. Therefore, passengers can be protected in the event of a thermal runaway event, and thus the safety of the battery pack can be improved.

[0035] In addition, even when the deformation amount of the bottom wall of the battery pack case exceeds the height of the free volume provided to the battery pack case 501 due to external impact, the protruding extension of the bottom cover plate can also be used as a protective member to protect the battery cell blocks, thereby improving the safety of the battery pack. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 is a perspective view showing a battery cell assembly according to an exemplary embodiment of the present disclosure.

[0037] Figure 2 is a perspective view showing a battery cell assembly according to an exemplary embodiment of the present disclosure.

[0038] Figure 3 is an exploded perspective view showing a battery cell assembly according to an exemplary embodiment of the present disclosure.

[0039] Figure 4A is a cross-sectional view showing a battery cell assembly according to an exemplary embodiment of the present disclosure.

[0040] Figure 4B is a cross-sectional view illustrating a portion of a bottom cover plate of a battery cell assembly according to an exemplary embodiment of the present disclosure.

[0041] Figure 5 is a cross-sectional view showing a battery pack according to an exemplary embodiment of the present disclosure.

[0042] Figure 6 is a cross-sectional view showing an operational example of a battery pack.

[0043] Figure 7 is a cross-sectional view showing a battery pack according to an exemplary embodiment of the present disclosure.

[0044] Figure 8 is a cross-sectional view showing a battery pack according to another exemplary embodiment of the present disclosure.

[0045] Fig.9A is a cross-sectional view showing a battery pack according to still another exemplary embodiment of the present disclosure.

[0046] Fig. 9B It is shown Fig.9A A three-dimensional view of the bottom cover plate of the battery cell assembly shown in FIG.

[0047] Fig.10 is a schematic diagram illustrating an electric vehicle equipped with a battery pack according to an exemplary embodiment of the present disclosure. DETAILED DESCRIPTION

[0048] Hereinafter, exemplary embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. Prior to this, the terms and words used in this specification and claims should not be interpreted as limited to general or dictionary terms, but should be understood according to the technical concept of the present invention and interpreted according to the concepts appropriately defined by the inventor in order to best illustrate the present invention.

[0049] Therefore, since the implementation mode described herein and the configuration shown in the drawings are merely one of the embodiments of the present disclosure and do not represent the overall technical concept of the present disclosure, it should be understood that the present disclosure covers various equivalents, modifications and substitutions at the time of filing this application.

[0050] Furthermore, in the following description of the present disclosure, when it is determined that a detailed description of a known configuration or function incorporated herein may make the gist of the present disclosure rather unclear, the detailed description will be omitted.

[0051] Since the embodiments of the present disclosure are provided to more fully explain the present disclosure to those skilled in the art, the shapes and sizes of the components in the drawings may be exaggerated, omitted or schematically shown for the sake of clarity. Therefore, the size or ratio of each component does not fully reflect the actual size or ratio.

[0052] Figure 1 , Figure 2 , Figure 3 , Figure 4A and Figure 4B is a view showing a battery cell assembly 100 according to an exemplary embodiment of the present disclosure, wherein Figure 1 and Figure 2 1 is a perspective view showing a battery cell assembly 100 viewed from different directions. Figure 3 is an exploded perspective view showing a battery cell assembly 100, Figure 4A is a cross-sectional view showing a battery cell assembly 100, and Figure 4B is a cross-sectional view showing a portion of the bottom cover plate 125 of the battery cell assembly 100 .

[0053] Reference Figures 1 to 4B The battery cell assembly 100 may include a cell block 110 , a housing 120 , and a bus bar frame assembly 141 .

[0054] The battery cell block 110 may include a plurality of battery cells 111. Each battery cell 111 is a basic unit of a lithium-ion battery (i.e., a secondary battery). Each battery cell 111 may include an electrode assembly, an electrolyte, and a cell shell. The electrode assembly embedded in the cell shell may include a positive electrode, a negative electrode, and a separator between the positive electrode and the negative electrode. Depending on the assembly type, the electrode assembly may be any one of a roll-type electrode assembly and a stacked electrode assembly. The roll-type electrode assembly may include a winding structure of a positive electrode, a negative electrode, and a separator interposed between the positive electrode and the negative electrode. The stacked electrode assembly may include a plurality of positive electrodes, a plurality of negative electrodes, and a plurality of separators interposed therebetween, all of which are sequentially stacked on each other. The positive electrode may include a positive electrode current collector and a positive electrode active material. The negative electrode may include a negative electrode current collector and a negative electrode active material.

[0055] The plurality of battery cells 111 may be connected in series and / or in parallel. As an embodiment, the plurality of battery cells 111 may be connected in series with each other. As another embodiment, the plurality of battery cells 111 may be connected in parallel with each other. As another embodiment, when a group of two or more battery cells 111 connected in parallel with each other is defined as a group, a group consisting of two or more battery cells 111 connected in parallel with each other and another group consisting of two or more battery cells 111 connected in parallel with each other may be connected in series.

[0056] Each battery cell 111 may correspond to a pouch-type battery cell, a cylindrical battery cell, or a prismatic battery cell. The electrode assembly may be included in various cell casings, for example, a pouch, a cylindrical can, or a prismatic can. The electrode assembly of a pouch-type battery cell may be included in a pouch casing including an aluminum laminate. The electrode assembly of a cylindrical battery cell may be included in a cylindrical metal can. The electrode assembly of a prismatic battery cell may be included in a prismatic metal can. Each battery cell 111 may include a vent facing the first space. For example, the vent of each battery cell 111 may be disposed in the cell casing of the battery cell 111. When the pressure in the cell casing of each battery cell 111 exceeds a certain level, the gas within the cell casing of each battery cell 111 may be discharged into the first space via the vent of each battery cell 111. The first space may be disposed in the lower housing 510 (see Figure 5 ) of the bottom wall 511 (see Figure 5 ) and the battery cell assembly 100 (see Figure 5 )between.

[0057] In an exemplary embodiment, each battery cell 111 may correspond to a pouch-type battery cell, and a plurality of battery cells 111 may be stacked in a battery cell assembly 100 (eg, Figure 3 ). In an exemplary embodiment, in each battery cell assembly 100, each of the plurality of battery cells 111 may correspond to a pouch-type battery cell having a length (thickness) in a first direction (X direction) that is less than a length in a second direction (Y direction), and the plurality of battery cells 111 may be stacked in the first direction (X direction). In an exemplary embodiment, each battery cell 111 may be a pouch-type battery cell, and a sealed portion of a bag in the pouch-type battery cell may face the first space so as to easily discharge gas and / or flame from the battery cell. When the pressure in the bag exceeds a certain level, the sealed portion of the bag is partially ruptured, and the gas in the bag may be discharged into the first space via the ruptured portion of the sealed portion.

[0058] When viewed in a plan view, the cell block 110 may have a rectangular shape. In this case, the cell block 110 may have a first side surface and a second side surface opposite to each other in a first direction (X direction), a front surface and a rear surface opposite to each other in a second direction (Y direction), and a top surface and a bottom surface opposite to each other in a third direction (Z direction).

[0059] The bus bar frame assembly 141 may be provided on each of the front surface and the rear surface of the cell block 110. The bus bar frame assembly 141 may include a bus bar frame and a plurality of bus bars mounted on the bus bar frame. The plurality of bus bars may be mounted on the bus bar frame at the front surface of the cell block 110, and may also be mounted on the bus bar frame at the rear surface of the cell block 110. The battery cell assembly 100 may further include an end plate 145 for covering the bus bar frame assembly 141 connected to each of the front surface or the rear surface of the cell block 110.

[0060] The bus bar may be coupled to the electrode leads of the battery cell 111. For example, the bus bar may be coupled to the electrode leads of the battery cell 111 by a welding method. For example, each bus bar may be an intermediate bus bar for electrically connecting different battery cells 111 belonging to the cell block 110 by being connected to the electrode leads connected to the different battery cells 111. For example, each bus bar may be a terminal bus bar for electrically connecting the battery cell assembly 100 to other external electrical devices.

[0061] In an exemplary embodiment, the battery cell assembly 100 may include a single cell block 110. In another exemplary embodiment, the battery cell assembly 100 may include a cell block array consisting of a plurality of cell blocks 110 arranged along a second direction (Y direction). For example, the battery cell assembly 100 may include two cell blocks 110 arranged along the second direction (Y direction). As an embodiment, the battery cell assembly 100 may include a first cell block and a second cell block arranged along the second direction (Y direction), and a bus bar frame assembly 141 connected to the rear surface of the first cell block and a bus bar frame assembly 141 connected to the front surface of the second cell block may be disposed between the first cell block and the second cell block. The first cell block may be electrically connected to the second cell block by means of an electrical connection structure extending between the bus bar frame assembly 141 connected to the rear surface of the first cell block and the bus bar frame assembly 141 connected to the front surface of the second cell block. One end plate 145 may be coupled to the bus bar frame assembly 141 at the front surface of the first cell block, and the other end plate 145 may be coupled to the bus bar frame assembly 141 at the rear surface of the second cell block.

[0062] The housing 120 may house the cell blocks 110. For example, the housing 120 may surround the top surface, the bottom surface, the first side surface, and the second side surface of each cell block 110 included in the battery cell assembly 100. The housing 120 may include a top cover plate 121 facing the top surface of the cell block 110, a bottom cover plate 125 facing the bottom surface of the cell block 110, and two side cover plates 123 facing the first side surface and the second side surface of the cell block 110, respectively.

[0063] The top cover plate 121 may cover the top surface of the cell block 110. For example, the top cover plate 121 may cover the top surfaces of all the cell blocks 110 disposed in the battery cell assembly 100. The top cover plate 121 may be attached to the top surface of the cell block 110 and may be thermally coupled to the cell block 110. The top cover plate 121 may be attached to the top surface of the cell block 110 by means of a first thermally conductive adhesive layer 131 interposed between the top cover plate 121 and the top surface of the cell block 110. For example, the first thermally conductive adhesive layer 131 may include a thermal interface material (TIM). The top cover plate 121 may have a first cooling passage 1211 and may be configured to cool the cell block 110, the first cooling passage 1211 being configured to allow a cooling fluid to flow therethrough. The top cover plate 121 may be referred to as a cooling plate. The top cover plate 121 may be configured to cool the cell block 110 by thermally coupling to the cell block 110 via the first thermally conductive adhesive layer 131. The cooling fluid provided from the outside of the battery cell assembly 100 may flow into the first cooling passage 1211 through the inlet of the first cooling passage 1211, flow along the first cooling passage 1211, and then flow out to the outside through the outlet of the first cooling passage 1211. The battery cell assembly 100 may be cooled while the cooling fluid flows along the first cooling passage 1211. For example, the cooling fluid may be cooled by joining two plates 1213 and 1215 (e.g., Figure 1 ) is used to manufacture the top cover plate 121, and the first cooling passage 1211 may include a space defined between the two plates 1213 and 1215.

[0064] The bottom cover plate 125 may be connected to the bottom surface of the cell block 110. For example, the bottom cover plate 125 may extend along the bottom surfaces of all the cell blocks 110 disposed in the battery cell assembly 100. The bottom cover plate 125 may include an exhaust passage 125v for exhausting high temperature gas generated in the cell block 110 to a space (first space) below the cell block 110. For example, the exhaust passage 125v of the bottom cover plate 125 is connected to the free volume FV (for example, disposed in the battery pack housing 501 (see Figure 5 ) in the first space (see Figure 5 )) is connected, and can form a channel for discharging gas or flame in the battery pack housing 501 together with the free volume FV.

[0065] The bottom cover plate 125 may include a plurality of protruding extensions 125p protruding toward the free volume FV (first space) of the battery pack housing 501. The plurality of protruding extensions 125p may each extend in a horizontal direction (e.g., X direction) along the bottom surface of the battery cell block 110. For example, the bottom cover plate 125 may include a main board 125m and a plurality of protruding extensions 125p connected to the bottom surface of the main board 125m.

[0066] The main board 125m may include a plurality of first exhaust channels 1251 that vertically pass through the main board 125m. The first exhaust channel 1251 may be a through hole that vertically passes through the main board 125m. The first exhaust channel 1251 may extend in a vertical direction (e.g., Z direction) perpendicular to the bottom surface of the battery cell block 110, and may guide a fluid (e.g., gas) or flame in a vertical direction. Each of the plurality of protruding extensions 125p may include a second exhaust channel 1253 that is connected to the first exhaust channel 1251. The second exhaust channel 1253 may extend in a direction different from the extension direction of the first exhaust channel 1251. For example, the extension direction of the second exhaust channel 1253 may intersect or be perpendicular to the extension direction of the first exhaust channel 1251. For example, the second exhaust channel 1253 may extend in a horizontal direction (e.g., X direction) along the bottom surface of the battery cell block 110 to guide a fluid (e.g., gas) or flame in a horizontal direction (e.g., X direction). The second exhaust passage 1253 may include an inlet communicating with the first exhaust passage 1251 and an outlet communicating with the free volume FV (first space) of the battery pack housing 501. The second exhaust passage 1253 may have one outlet communicating with the free volume FV (first space) of the battery pack housing 501, or a plurality of outlets communicating with the free volume FV (first space) of the battery pack housing 501.

[0067] The first exhaust channel 1251 and the second exhaust channel 1253 may be connected to each other to form an exhaust channel 125v of the bottom cover plate 125. Therefore, the exhaust channel 125v of the bottom cover plate 125 may include a portion extending in the vertical direction and a portion extending in the horizontal direction. The exhaust channel 125v of the bottom cover plate 125 may allow the high-temperature gas or flame generated by the battery cell block 110 to be discharged into the free volume FV (first space) of the battery pack housing 501 along a predetermined direction. For example, the high-temperature gas or flame generated in the battery cell block 110 flows downward along the first exhaust channel 1251, flows in a horizontal direction (e.g., X direction) along the second exhaust channel 1253, and is discharged to the free volume FV (first space) of the battery pack housing 501 via the outlet of the second exhaust channel 1253. The gas discharged via the outlet of the second exhaust channel 1253 may be discharged in the free volume FV (first space) of the battery pack housing 501 in a horizontal direction (e.g., Figure 4BThe horizontal direction is the direction in which the second exhaust passage 1253 extends.

[0068] In an exemplary embodiment, in the main board 125m of the bottom cover plate 125, a plurality of first exhaust passages 1251 may be arranged along the second direction ( Figure 2 The plurality of battery cells 111 are stacked in each cell block 110 along a first direction (X direction) when viewed in a plan view, and each first exhaust passage 1251 may extend along the first direction (X direction). Figure 3 and 4A When viewed in a plan view, a length of the first exhaust passage 1251 in a first direction (X direction) may be greater than a length of the first exhaust passage 1251 in a second direction (Y direction).

[0069] In an exemplary embodiment, the arrangement of the plurality of protruding extensions 125p of the bottom cover plate 125 may correspond to the arrangement of the plurality of first exhaust passages 1251. The plurality of protruding extensions 125p may be arranged in the second direction (Y direction) and may be spaced apart from each other in the second direction (Y direction). Each of the plurality of protruding extensions 125p may be located below the corresponding first exhaust passage 1251. In the protruding extension 125p, the second exhaust passage 1253 extends in the horizontal direction (e.g., X direction), and the outlet of the second exhaust passage 1253 may be located on the side of the protruding extension 125p in the horizontal direction (e.g., X direction).

[0070] In an exemplary embodiment, Figure 4B As shown in , the second exhaust channel 1253 of the protruding extension 125p may extend in the first direction (X direction), and may have an outlet in the side portion of the protruding extension 125p along the first direction (X direction). In this case, the gas generated in the battery cell block 110 is discharged to the free volume FV (first space) of the battery pack housing 501 via the outlet of the second exhaust channel 1253, and the gas discharged via the outlet of the second exhaust channel 1253 generally flows in the first direction (X direction), and the first direction is the extension direction of the second exhaust channel 1253. However, the direction of the exhaust channel of the present disclosure and its arrangement are not limited thereto.

[0071] The side cover plates 123 may be provided on each of one side and the other side of the cell block 110. For example, one of the side cover plates 123 may extend along a first side surface of all the cell blocks 110 provided in the battery cell assembly 100, and the other of the side cover plates 123 may extend along a second side surface of all the cell blocks 110 provided in the battery cell assembly 100.

[0072] In an exemplary embodiment, the battery cell assembly 100 may have a side mounting structure that is fastened to the battery pack housing 501 via the side cover plate 123. In this case, the side cover plate 123 may include a fastening portion 1231 fastened to the battery pack housing 501 (in which the battery cell assembly 100 is mounted) by a fastening member such as a bolt. The fastening portion 1231 may include a fastening hole H1 through which the bolt is fastened.

[0073] In other exemplary embodiments, the battery cell assembly 100 may have a mounting structure in which the upper end portion of the battery cell assembly 100 is directly fastened to the battery pack housing 501 , and in this case, the fastening portion 1231 of the side cover plate 123 may be omitted.

[0074] Figure 5 is a cross-sectional view showing a battery pack 500 according to an exemplary embodiment of the present disclosure. Figure 6 is a cross-sectional view showing an operational embodiment of the battery pack 500. Hereinafter, descriptions overlapping with the above descriptions will be omitted or simplified.

[0075] Reference Figure 5 , the battery pack 500 may include a battery pack case 501 and a battery cell assembly 100 installed in the battery pack case 501. The battery pack 500 may include one or more battery cell assemblies 100 installed in the battery pack case 501. In an exemplary embodiment, the battery pack 500 may include two or more battery cell assemblies 100 arranged along a first direction (X direction).

[0076] The battery pack housing 501 may include a housing 510 having an accommodation space and an opening, in which the battery cell assembly 100 is accommodated, and a battery pack cover 520 coupled to the housing 510 so as to cover the opening of the housing and cover the battery cell assembly 100 accommodated in the housing 510. The accommodation space of the housing 510 may be defined by a bottom wall 511 facing the bottom surface of the cell block 110 of each battery cell assembly 100 and a side wall 513 located at the periphery of the bottom wall 511. When the battery pack 500 is installed in a vehicle, a passenger compartment in which passengers board may be located above the battery pack cover 520, and a ground on which the vehicle travels may be located below the housing 510.

[0077] In an exemplary embodiment, the battery cell assembly 100 may be fixed to and supported by the pack cover 520. In another exemplary embodiment, the battery cell assembly 100 may be fixed to the housing 510 by means of a fastening member such as a bolt.

[0078] The free volume FV (first space) may be provided between the bottom surface of the battery cell assembly 100 and the bottom wall 511 of the housing 510. The free volume FV may be understood as a space formed by the bottom wall 511 of the housing 510 and each battery cell assembly 100 being spaced apart from each other. In this specification, the free volume FV (first space) may be referred to as a venting space or a buffer space.

[0079] The free volume FV may be in communication with the exhaust passage 125v of the bottom cover plate 125. Figure 7 As shown in FIG. 1 , the free volume FV (first space) can constitute an exhaust path VP together with the exhaust channel 125v of the bottom cover plate 125 (see FIG. 1 ). Figure 7 ), the high temperature gas or flame generated in the battery cell assembly 100 inside the battery pack 500 is discharged via the exhaust path VP. For example, the high temperature gas or flame generated in the battery cell 111 may flow into the free volume FV via the exhaust channel 125v of the bottom cover plate 125, move in the lateral direction in the battery pack housing 501, and then flow to the exhaust portion, such as the exhaust device 530 (e.g., connected to one side of the battery pack housing 501). Figure 7 ). The exhaust device 530 may include a path (e.g., an exhaust passage) for exhausting gas and / or heat within the battery pack 500. When the battery cell assembly 100 is in a thermal runaway state, the exhaust device 530 may delay heat propagation by exhausting gas and / or heat inside the battery pack 500 to the outside. The exhaust channel 125v of the bottom cover plate 125 may allow the high-temperature gas generated in the battery cell block 110 to have a predetermined direction (e.g., toward the direction of the exhaust device 530). In this case, since the free volume FV (first space) and the exhaust channel 125v are used as a directional exhaust channel in a thermal runaway event, passengers can be protected in the event of a thermal runaway event.

[0080] In addition, the top surface of the battery cell assembly 100 may be tightly coupled to the bottom surface of the battery pack cover 520. When there is a space between the battery cell assembly 100 and the battery pack cover 520, during a thermal runaway event, high temperature gas may be introduced into the space between the battery cell assembly 100 and the battery pack cover 520, and thus heat and flame may propagate to another adjacent battery cell assembly 100. In addition, there is a concern that heat and flame may be conducted to the battery pack cover 520 to affect the passenger compartment above the battery pack cover 520. According to an embodiment of the present disclosure, since the top surface of the battery cell assembly 100 and the bottom surface of the battery pack cover 520 are tightly coupled to each other, gas or flame generated from the battery cell assembly 100 may be introduced into the exhaust passage 125v and the free volume FV (first space).

[0081] In addition, if Figure 6As shown in , when a strong external impact ES is applied to the battery pack 500 due to a foreign object that rebounds onto the bottom of the vehicle in a hard ground driving situation such as an unpaved road, the free volume FV (first space) can absorb or buffer the external impact. Therefore, multiple battery cell assemblies 100 can be prevented from being damaged due to the impact. The free volume FV (first space) has an empty space between each of the multiple battery cell assemblies 100 and the housing 510, and when the housing 510 is deformed toward the battery cell assembly 100 due to the impact applied to the bottom of the vehicle, the free volume FV can be used as a space that allows some deformation freedom of the housing 510. No other structures may be installed in the free volume FV. Alternatively, a structure for supporting the battery cell assembly 100, etc. may be partially installed in the free volume FV. When such a structure is installed in the free volume FV, a space for allowing the housing 510 to deform should be provided between the battery cell assembly 100 and the housing 510.

[0082] The height of the free volume FV (first space) (i.e., the distance between the bottom wall 511 of the housing 510 and the battery cell assembly 100) can be set to fully absorb external impact. The height of the free volume FV can be determined in consideration of the size and rigidity of the vehicle frame, the size and rigidity of the housing 510, the size of the battery pack 500, the amount of gas generated during thermal runaway and the discharge speed, etc. For example, when the thickness or rigidity of the bottom wall 511 of the vehicle frame or the housing 510 is relatively large, at least one of the size and height of the free volume FV can be relatively reduced. In addition, when the thickness or rigidity of the bottom wall 511 of the vehicle frame or the housing 510 is relatively small, the possibility of deformation of the bottom wall 511 of the housing 510 is large, so at least one of the size and height of the free volume FV can be relatively increased to protect the battery cell assembly 100. In addition, when the size of the battery pack 500 is relatively large according to the specifications of the battery pack 500, a relatively large free volume FV can be ensured. When the size of the battery pack 500 is relatively small, the height of the free volume FV that can be ensured can be relatively small, and the thickness and rigidity of the bottom wall 511 of the housing 510 may need to be relatively increased. In addition, when the height of the free volume FV is too small, the gas discharge channel is reduced, so that the internal pressure of the battery pack 500 may increase sharply during thermal runaway. Therefore, the size and height of the free volume FV (first space) can be determined in consideration of the amount of gas generated and the discharge speed.

[0083] The maximum height of the free volume FV (first space) may be determined according to the degree of damage of the battery cell 111 included in the battery cell assembly 100. For example, when the allowable damage limit of the battery cell 111 is 1 mm, the free volume FV may be determined so that when the housing 510 is deformed and presses the bottom surface of the battery cell 111, the deformation of the battery cell 111 does not exceed 1 mm. In this case, the deformation amount of the housing 510 may be changed according to the thickness or rigidity of the housing 510. Therefore, the size or height of the free volume FV may be determined in consideration of both the allowable damage limit of the battery cell 111 and the thickness and rigidity of the housing 510.

[0084] According to an exemplary embodiment of the present disclosure, since the free volume FV used as a buffer for external impact is set between the bottom of the battery pack 500 (i.e., the bottom wall 511 of the outer shell 510) and the battery cell assembly 100, damage to the battery cell assembly 100 and / or the battery cell 111 due to external impact can be prevented, and ultimately the safety of the battery pack 500 can be improved.

[0085] Furthermore, according to an exemplary embodiment of the present disclosure, the free volume FV and the exhaust passage 125v provided in the bottom cover plate 125 of the battery cell assembly 100 together form a directional exhaust passage in the battery pack 500, and high-temperature gas or flame in the battery pack 500 can be discharged to the outside of the battery pack 500 via the directional exhaust passage. Therefore, passengers can be protected in the event of a thermal runaway event, and thus the safety of the battery pack 500 can be improved.

[0086] In addition, if Figure 6 As shown in FIG. 5 , in the case where an external impact ES is applied to the battery pack 500, the bottom cover plate 125 can prevent damage to the battery cell assembly 100. For example, even when the deformation amount of the bottom wall 511 of the battery pack housing 501 exceeds the height of the free volume FV (first space) provided to the battery pack housing 501 due to the external impact ES, the protruding extension 125p of the bottom cover plate 125 can also be used as a protective member to protect the cell block 110, thereby improving the safety of the battery pack 500.

[0087] Figure 7 is a cross-sectional view showing a battery pack 500A according to an exemplary embodiment of the present disclosure. Hereinafter, descriptions overlapping with the above descriptions will be omitted or simplified.

[0088] Reference Figure 7 The battery pack 500A may include a battery pack housing 501 and a plurality of battery cell assemblies 100 installed in the battery pack housing 501 .

[0089] A plurality of battery cell assemblies 100 may be installed in the battery pack housing 501 to be arranged along a first direction (X direction). Figure 7 5. The battery pack 500A is shown as including four battery cell assemblies 100 arranged along the first direction (X direction), but the present disclosure is not limited thereto. For example, the battery pack 500A may include two or more battery cell assemblies 100 arranged along the first direction (X direction).

[0090] Each of the plurality of battery cell assemblies 100 may have a side mounting structure fastened to a support block 515 of the battery pack housing 501 by means of a side cover plate 123 provided on one or both sides thereof. More specifically, the support block 515 may be provided on the bottom wall 511 of the battery pack housing 501, and a fastening portion 1231 provided in the side cover plate 123 of each battery cell assembly 100 may be fastened to a corresponding one of the support blocks 515 by means of a fastening member such as a bolt.

[0091] According to an exemplary embodiment of the present disclosure, since a plurality of battery cell assemblies 100 are fastened to the battery pack housing 501 in the battery pack 500A by a side mounting method, damage due to expansion of the battery cells 111 can be reduced and structural safety of the plurality of battery cell assemblies 100 can be improved.

[0092] Figure 8 is a cross-sectional view showing a battery pack 500B according to an exemplary embodiment of the present disclosure. Hereinafter, descriptions overlapping with the above descriptions will be omitted or simplified.

[0093] Reference Figure 8 , the battery pack 500B may include a battery pack housing 501 and a battery cell assembly 100 installed in the battery pack housing 501. The battery cell assembly 100 may be in contact with the bottom surface of the battery pack cover 520. For example, the battery cell assembly 100 may be in close contact with the bottom surface of the battery pack cover 520 by means of a second thermally conductive adhesive layer 531 interposed between the battery cell assembly 100 and the battery pack cover 520. For example, the second thermally conductive adhesive layer 531 may include a thermal interface material (TIM). The second thermally conductive adhesive layer 531 may prevent the formation of an air layer between each battery cell assembly 100 and the battery pack cover 520. The second thermally conductive adhesive layer 531 may be configured to conduct heat between the battery cell assembly 100 and the battery pack cover 520. Therefore, the heat of the battery cell assembly 100 may be discharged toward the battery pack cover 520 via the second thermally conductive adhesive layer 531.

[0094] When the battery pack cover 520 is provided with a suitable cooling device, the heat of the battery cell assembly 100 can be conducted to the cooling device via the second heat conductive adhesive layer 531. The cooling device may include a second cooling passage 521, which is provided to the battery pack cover 520 and through which a cooling fluid flows. When the second cooling passage 521 is provided in the battery pack cover 520, the first cooling passage provided in the top cover plate 121 may be omitted (see Figure 5 1211 in). However, the present disclosure is not limited thereto. If both the first cooling passage 1211 and the second cooling passage 521 are used in the battery pack, the cooling fluids of the first / second cooling passages may be the same or different from each other. Since the second thermally conductive adhesive layer 531 is disposed between the top surface of each battery cell assembly 100 and the battery pack cover 520, and the second cooling passage 521 is disposed in the battery pack cover 520, the battery cell assembly 100 can be cooled.

[0095] Fig.9A is a cross-sectional view showing a battery pack 500C according to an exemplary embodiment of the present disclosure. Fig. 9B It is shown Fig.9A 1 is a perspective view of a bottom cover plate 125A of a battery cell assembly 100 shown in FIG. 1 . Hereinafter, descriptions overlapping with the above descriptions will be omitted or simplified.

[0096] Reference Fig.9A and Fig. 9B In the battery cell assembly 100 of the battery pack 500C, the bottom cover plate 125A may have a substantially flat plate shape. The bottom cover plate 125A includes exhaust passages 125v vertically passing through the bottom cover plate 125A, and each of the exhaust passages 125v may communicate with the free volume FV (first space). Fig.9A and Fig. 9B The bottom cover plate 125A shown in FIG. 1 can be used with reference to Figures 1 to 4B The bottom cover plate 125 described above is substantially the same or similar with the protruding extension 125p removed.

[0097] Fig.10 is a schematic diagram showing an electric mobility device (eg, electric vehicle) 1000 equipped with a battery pack 1100 according to an exemplary embodiment of the present disclosure.

[0098] exist Fig.10 In the embodiment, for the sake of simplicity, only the vehicle body frame 1200 forming the lower frame of the vehicle, the battery pack 1100 coupled to the vehicle body frame 1200, and the tire are shown. The battery pack 1100 may include a reference Figure 5 , Figure 7 , Figure 8 and Fig.9A Described are battery packs 500, 500A, 500B, and 500C.

[0099] In the case of a typical battery pack, the battery cell assembly is mounted on the bottom of a battery pack case of the battery pack. However, in the present embodiment, the battery cell assembly 100 of the battery pack 1100 may have a structure supported by the battery pack cover 520 of the battery pack case, and the first space may be provided below the battery cell assembly 100. That is, since there is no space between the battery cell assembly 100 and the battery pack cover 520, the gas generated in the battery cell assembly 100 may be prevented from being conducted to the passenger compartment at the upper portion of the vehicle. The gas and / or flame is directed to the first space (free volume FV, see Figure 5 The gas / flame flows through the first space (free volume FV) and is discharged through an exhaust portion (e.g., exhaust device 530 ( Figure 7 In one embodiment of the present disclosure, the exhaust portion may be located on the side of the housing that faces the rear side of the electric mobile device. In one embodiment of the present disclosure, the exhaust portion may include a pressure relief valve and / or a rupture valve. In addition, according to the present embodiment, since the free volume FV is provided between the battery cell assembly 100 and the battery pack housing in the battery pack 1100, damage to the battery cell assembly 100 may be prevented even if the battery pack housing is deformed.

[0100] According to an embodiment of the present disclosure, the battery pack 1100 and an electric mobile device (e.g., an electric vehicle 1000) having the battery pack 1100 can improve the safety of passengers. In addition, the battery cell assembly 100 as a key component can be protected, and the durability of the battery pack 1100 and the electric mobile device 1000 can be improved.

[0101] As described above, the present disclosure has been described in more detail with the aid of the drawings and embodiments. However, since the configuration described in the drawings or embodiments described herein is only one embodiment of the present disclosure and does not represent the overall technical concept of the present disclosure, it should be understood that the present disclosure covers various equivalents, modifications and substitutions at the time of filing this application.

[0102] [Explanation of Reference Numerals]

[0103] 100: battery cell assembly, 110: battery cell block

[0104] 111: battery cell, 120: housing

[0105] 121: Top cover, 123: Side cover

[0106] 125: bottom cover, 125v: exhaust channel

[0107] 500: battery pack, 510: housing

[0108] 520: Battery pack cover.

Claims

1. A battery pack, comprising: A battery cell assembly, the battery cell assembly comprising a cell block having a plurality of battery cells and a bottom cover plate below a bottom surface of the cell block; a housing having an opening and accommodating the battery cell assembly; as well as a battery pack cover coupled to the housing and covering the opening, wherein the battery cell assembly and the bottom wall of the housing are spaced apart from each other to form a first space, and Wherein, the bottom cover plate includes an exhaust passage communicated with the first space.

2. The battery pack according to claim 1, wherein: The bottom cover plate also includes: a protruding extension portion that protrudes toward the first space and extends in a first direction along the bottom surface of the cell block, The exhaust passage includes a portion extending along the first direction in the protruding extension portion.

3. The battery pack according to claim 1, wherein: The bottom cover plate also includes: a main board, the main board facing the bottom surface of the battery core block; and a protruding extension portion extending in a first direction along the bottom surface of the battery core block below the main board, Wherein, the exhaust passage comprises: A first exhaust passage vertically passing through the main board; and A second exhaust passage extends in the protruding extension along the first direction and has an inlet connected to the first exhaust passage and an outlet connected to the first space.

4. The battery pack according to claim 3, wherein: The first exhaust passage extends in a vertical direction, and Wherein, the second exhaust channel extends in a horizontal direction.

5. The battery pack according to claim 1, wherein: The battery cell assembly also includes: a top cover plate on the top surface of the battery cell block, The top cover plate includes a first cooling passage configured to allow a first cooling fluid to flow therethrough.

6. The battery pack according to claim 5, wherein: The battery cell assembly also includes: A first thermally conductive adhesive layer is provided between the top cover plate and the core block.

7. The battery pack according to claim 1, wherein: The battery cell assembly is coupled to the battery pack cover.

8. The battery pack according to claim 7, wherein: The battery pack cover includes a second cooling passage configured to allow a second cooling fluid to flow therethrough.

9. The battery pack according to claim 8, further comprising: A second thermally conductive adhesive layer is provided between the battery cell assembly and the battery pack cover.

10. The battery pack according to claim 1, wherein: The battery cell assembly also includes: a side cover plate on at least one side of the battery block, and Wherein, the side cover is fastened to the housing.

11. The battery pack according to claim 1, wherein: The battery cell assembly further includes side covers spaced apart from each other, the cell blocks are arranged between the side covers, and Wherein, the side cover plates are fastened to different support blocks arranged in the housing.

12. The battery pack according to claim 11, wherein: A sealed portion of the pouch in the pouch-type battery cell faces the first space.

13. The battery pack according to claim 1, wherein: Each of the plurality of battery cells is a cylindrical battery cell or a prismatic battery cell and includes a vent.

14. The battery pack according to claim 13, wherein: The exhaust portion of the cylindrical battery cell or the prismatic battery cell faces the first space.

15. An electric mobile device comprising a battery pack, the battery pack comprising: A battery cell assembly, the battery cell assembly comprising a cell block having a plurality of battery cells and a bottom cover plate below a bottom surface of the cell block; a housing having an opening and accommodating the battery cell assembly; as well as a battery pack cover coupled to the housing and covering the opening, wherein the battery cell assembly and the bottom wall of the housing are spaced apart from each other to form a first space, and Wherein, the bottom cover plate includes an exhaust passage communicated with the first space.

16. The electric mobile device according to claim 15, wherein: The electric mobility device is an electric vehicle.

17. The electric mobile device according to claim 15, wherein: The battery pack further comprises: A discharge portion communicated with the first space.

18. The electric mobile device according to claim 17, wherein: The discharge portion is located at a side of the housing facing the rear side of the electric moving device.

19. A battery pack, comprising: A battery cell assembly, the battery cell assembly comprising a cell block having a plurality of battery cells, a top cover plate on a top surface of the cell block, a bottom cover plate below a bottom surface of the cell block, a side cover plate on at least one side of the cell block, and a first thermally conductive adhesive layer between the top cover plate and the cell block; a housing having an opening and accommodating the battery cell assembly; a battery pack cover coupled to the housing and covering the opening; as well as a second thermally conductive adhesive layer, the second thermally conductive adhesive layer being located between the battery cell assembly and the battery pack cover, The battery cell assembly and the bottom wall of the housing are spaced apart from each other to form a first space. Wherein, the bottom cover plate includes an exhaust passage communicating with the first space, wherein the top cover plate comprises a first cooling passage configured to allow a first cooling fluid to flow therethrough, and Wherein, the battery pack cover includes a second cooling passage configured to allow a second cooling fluid to flow therethrough.

20. The battery pack according to claim 19, further comprising: A discharge portion communicated with the first space.

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