Battery pack

Abstract

A battery pack according to an embodiment of the present invention may include a housing and a plurality of battery units disposed within the housing. The battery unit may include a first battery cell extending parallel to a width direction of the housing, a second battery cell disposed on one side of the first battery cell in the width direction of the housing and aligned parallel to the first battery cell, and a rigid case extending parallel to the width direction of the housing and accommodating the first battery cell and the second battery cell as a whole. The case may be formed with a first vent hole toward the first battery cell and a second vent hole toward the second battery cell, and the housing may be provided with a vent passage communicating with the first vent hole and the second vent hole.

Description

[Technical field]

[0001] The present invention relates to a battery pack, and more particularly to a battery pack including a plurality of battery cells.

[0002] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of priority based on Korean Patent Application No. 10-2022-0023257, filed on February 22, 2022, and Korean Patent Application No. 10-2023-0023122, filed on February 21, 2023, and all contents disclosed in the documents of said Korean patent applications are incorporated herein by reference. [Background technology]

[0003] Secondary batteries, which have high applicability according to product groups and electrical properties such as high energy density, are widely used not only in portable devices but also in electric vehicles (EVs) and hybrid electric vehicles (HEVs) that are driven by electric drive sources. These secondary batteries are attracting attention as a new energy source for improving the environment and energy efficiency, not only because they have the primary advantage of dramatically reducing the use of fossil fuels, but also because they do not produce any by-products due to the use of energy.

[0004] Currently, the types of secondary batteries that are widely used include lithium ion batteries, lithium polymer batteries, nickel cadmium batteries, nickel metal hydride batteries, nickel zinc batteries, etc. In addition, a battery pack that satisfies the required output voltage and charge / discharge capacity conditions can be configured by connecting a plurality of battery cells in series and / or parallel. The number of battery cells included in the battery pack can be set in various ways depending on the required output voltage or charge / discharge capacity.

[0005] Meanwhile, a battery pack may be configured by connecting a plurality of battery cells in series / parallel. In this case, the battery pack may include a housing and a plurality of battery modules housed in the housing, and each battery module may include at least one battery cell.

[0006] In conventional battery pack housings, reinforcing members (e.g., cross beams) are typically provided that connect some of the battery modules to other parts of the battery modules in order to maintain the rigidity of the battery pack, and each battery module is typically provided with a fastening member (e.g., a fastening boss, etc.) for mechanically fastening to the housing.

[0007] However, in the conventional battery pack, the reinforcing parts and the fastening parts occupy a part of the space within the housing, which reduces the space utilization rate and the energy density of the battery pack. Summary of the Invention [Problem to be solved by the invention]

[0008] One problem to be solved by the present invention is to provide a battery pack that maintains rigidity and improves energy density.

[0009] Another object of the present invention is to provide a battery pack in which gas generated in each battery unit can be smoothly discharged to the outside. [Means for solving the problem]

[0010] A battery pack according to an embodiment of the present invention may include a housing and a plurality of battery units disposed within the housing. The battery unit may include a first battery cell extending parallel to a width direction of the housing, a second battery cell disposed on one side of the first battery cell in the width direction of the housing and aligned parallel to the first battery cell, and a rigid case extending parallel to the width direction of the housing and accommodating the first battery cell and the second battery cell as a whole. The case may be formed with a first vent hole toward the first battery cell and a second vent hole toward the second battery cell, and the housing may be provided with a vent passage communicating with the first vent hole and the second vent hole.

[0011] The cases of the multiple battery units may be stacked so as to be in contact with each other or adjacent to each other.

[0012] The length of the case may be greater than half the distance between the side portions of the housing.

[0013] The housing may not be provided with a reinforcing portion disposed between some of the plurality of battery units and other parts of the plurality of battery units.

[0014] The housing may not be provided with a fastening portion that mechanically fastens the case to the inside of the housing.

[0015] The first and second vent holes may be formed in a bottom surface of the case, and the vent passage may be provided in a bottom portion of the housing.

[0016] The vent passage may include an inlet formed on an inner bottom surface of the housing and facing the first vent hole or the second vent hole, and a first passage communicating with the inlet and positioned between the inner bottom surface and the outer bottom surface of the housing.

[0017] The first flow path may extend parallel to the battery unit.

[0018] The vent passage may further include a second passage extending along a side portion of the housing and communicating with the first passage.

[0019] The bottom surface of the housing may include an extension that extends outwardly from the side surface of the housing, and the second flow path may be formed within the extension.

[0020] The second flow passage may be formed in a side portion of the housing.

[0021] The vent passage may further include an outlet located at an end of the second passage through which gas is exhausted outside the periphery of the housing.

[0022] An inner bottom surface of the housing may include a first region having an attachment member to which the plurality of battery units are attached, and a second region in which the inlet is formed.

[0023] The housing may be provided with a coolant flow passage located between an inner bottom surface and an outer bottom surface of the housing and partitioned from the first flow passage.

[0024] The coolant flow path may be located above the first flow path. Effect of the Invention

[0025] According to a preferred embodiment of the present invention, since the battery cells of each battery unit are arranged in series, the case may be long and narrow, and may be a rigid body. Thus, due to the self-rigidity and structural rigidity of the cases of the multiple battery units, the rigidity of the battery pack can be maintained without a separate reinforcing member, and the energy density of the battery pack can be improved compared to a case in which a separate reinforcing member is provided inside the housing.

[0026] In addition, gas flowing out from the first battery cell can be immediately discharged to the vent passage through the first vent hole, and gas flowing out from the second battery cell can be immediately discharged to the vent passage through the second vent hole, so that gas generated within the battery unit can be smoothly discharged to the outside.

[0027] In addition, the plurality of battery units can be attached to the housing by an attachment member provided on the bottom surface of the housing, and thus the plurality of battery units can be stably fixed in the housing without a separate fastening portion for mechanically fastening each battery unit to the housing, thereby improving the energy density of the battery pack compared to a case in which each battery unit is provided with a separate fastening portion.

[0028] In addition, the present invention may have other effects that can be easily predicted by a person skilled in the art from the configuration according to the preferred embodiment of the present invention. [Brief description of the drawings]

[0029] The following drawings attached to this specification are illustrative of preferred embodiments of the present invention and, together with the detailed description of the invention described below, serve to facilitate a better understanding of the technical concepts of the present invention. Therefore, the present invention should not be interpreted as being limited solely to the matters depicted in such drawings. [Figure 1] FIG. 1 is a perspective view of a battery pack according to one embodiment of the present invention. [Diagram 2] FIG. 2 is a plan view of a battery pack according to one embodiment of the present invention. [Diagram 3] 2 is a perspective view showing a state in which a plurality of battery units are removed from the battery pack shown in FIG. 1. FIG. [Figure 4] FIG. 2 is a perspective view of a battery unit according to one embodiment of the present invention. [Diagram 5] FIG. 2 is an exploded perspective view of a battery unit according to one embodiment of the present invention. [Figure 6]FIG. 2 is a plan view showing vent channels of a battery pack according to one embodiment of the present invention. [Figure 7] 7 is a cutaway view showing the inlet, the first flow path, and the second flow path of FIG. 6. FIG. [Figure 8] FIG. 13 is a plan view showing a vent passage of a battery pack according to another embodiment of the present invention. [Figure 9] 9 is a cutaway view showing the inlet, the first flow path, and the second flow path of FIG. 8. FIG. [Figure 10] FIG. 2 is a perspective view of a battery pack according to a comparative example. [Figure 11] FIG. 1 is a plan view of a battery pack according to a comparative example. [Figure 12] 11 is an enlarged view of the fastening portion shown in FIG. 10 and its surroundings. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0030] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily carry out the present invention. However, the present invention may be embodied in various different forms and is not limited to the following embodiments.

[0031] In order to clearly explain the present invention, detailed descriptions of parts that are not relevant to the description or related known technologies that may obscure the gist of the present invention will be omitted, and in this specification, when adding reference numbers to components in each drawing, the same or similar reference numbers will be used throughout the specification for the same or similar components.

[0032] Furthermore, the terms and words used in this specification and the claims should not be interpreted limited to their ordinary and dictionary meanings, but should be interpreted in a way that is consistent with the technical ideas of the present invention, based on the principle that the inventor himself / herself can appropriately define the concepts of terms in order to explain the invention in the best possible manner.

[0033] FIG. 1 is an oblique view of a battery pack according to one embodiment of the present invention, FIG. 2 is a plan view of a battery pack according to one embodiment of the present invention, FIG. 3 is an oblique view showing a state in which multiple battery units have been removed from the battery pack shown in FIG. 1, FIG. 4 is an oblique view of a battery unit according to one embodiment of the present invention, and FIG. 5 is an exploded oblique view of a battery unit according to one embodiment of the present invention.

[0034] 1 to 3, a battery pack 1 according to an embodiment of the present invention may include a housing 10 and a plurality of battery units 20 disposed in the housing 10.

[0035] The housing 10 may be roughly in the shape of a box with an open top, and may have an internal space capable of housing a plurality of battery units 20. When the plurality of battery units 20 are housed in the housing 10, the open top of the housing 10 may be covered with a cover (not shown).

[0036] More specifically, the housing 10 may include a front portion 11, a back portion 12, a pair of side portions 13, and a bottom portion 14.

[0037] The bottom surface portion 14 may be in the form of a plate formed approximately horizontally. The front surface portion 11, the rear surface portion 12, and the pair of side surface portions 13 may protrude upward from the bottom surface portion 14. The front surface portion 11, the rear surface portion 12, and the pair of side surface portions 13 may be located on the periphery of the bottom surface portion 14 or on the inside of the periphery.

[0038] The bottom portion 14 may include an extension portion 19 that extends outward from both side portions 13. The extension portion 19 may be configured for attaching the battery pack 1 to an electronic device (e.g., an electric vehicle) that is powered by the battery pack 1.

[0039] The pair of side portions 13 may connect the front portion 11 and the rear portion 12. The front portion 11 and the rear portion 12 may extend parallel to each other in a first direction (e.g., a direction parallel to the y-axis in FIG. 1), and the pair of side portions 13 may extend parallel to each other in a second direction perpendicular to the first direction (e.g., a direction parallel to the x-axis in FIG. 1). In this specification, the meaning of being parallel to each other or perpendicular to each other is not limited to an academic meaning, and may include a manufacturing error range.

[0040] The first direction may be a width direction of the housing 10, and the second direction may be a longitudinal direction of the housing 10.

[0041] A plurality of battery units 20 may be housed in the housing 10. Each battery unit 20 may be formed parallel to the width direction of the housing 10.

[0042] The length (L) of each battery unit 20 may be greater than half the distance (D) between the side portions 13 of the housing 10. Preferably, the length (L) of each battery unit 20 may be greater than or equal to 90% of the distance (D) between the side portions 13 of the housing 10. Both ends of each battery unit 20 may be in contact with or adjacent to both side portions 13 of the housing 10.

[0043] The multiple battery units 20 may be arranged in parallel to each other. The multiple battery units 20 may be stacked so as to be in contact with or adjacent to each other. The multiple battery units 20 may be stacked with respect to the longitudinal direction of the housing 10. The multiple battery units 20 may be arranged in a single row.

[0044] More specifically, referring to FIGS. 4 and 5, each battery unit 20 may include a case 21 extending parallel to the width direction of the housing 10 and a plurality of battery cells 22 housed in the case 21.

[0045] The case 21 may form the exterior of the battery unit 20. The case 21 may be in the form of a bar or beam extending parallel to the width direction of the housing 10.

[0046] The case 21 may be a rigid body. Preferably, the case 21 may include a metal material. Therefore, the rigidity of the battery pack 10 may be maintained high due to the rigidity of the case 21 of the plurality of battery units 20 itself.

[0047] The length (L) of the case 21 may be longer than half the distance (d) between the side portions 13 of the housing 10. Preferably, the length (L) of the case 21 may be 90% or more of the distance (d) between the side portions 13 of the housing 10. Both ends of the case 21 may be in contact with or adjacent to the side portions 13 of the housing 10.

[0048] The cases 21 of the multiple battery units 20 may be arranged parallel to one another. The cases 21 of the multiple battery units 20 may be stacked so as to be in contact with one another or adjacent to one another. The cases 21 of the multiple battery units 20 may be stacked with respect to the longitudinal direction of the housing 10. The cases 21 of the multiple battery units 20 may be arranged to form a single row.

[0049] The case 21 may be configured by fastening a plurality of parts. For example, as shown in Fig. 5, the case 21 may include a main body 21a with both ends and one side open, a first cover 21b covering the one side open of the main body 21a, and a pair of second covers 21c covering both open ends of the main body 21a. However, the configuration of the case 21 is not limited thereto.

[0050] Each battery cell 22 may be a pouch-type battery cell in which an electrode assembly and an electrolyte are housed in a pouch-type battery case, and the battery unit 20 including a plurality of battery cells 22 may be named a SPU (Scalable Pouch Unit).

[0051] The pouch-type battery case of the battery cell 22 is made of a soft material that is not rigid, and may not have sufficient rigidity. Therefore, in order to maintain high rigidity of the battery pack 10, it is important that the case 21 of the battery unit 20 is made of a rigid body.

[0052] The multiple battery cells 22 may extend parallel to the longitudinal direction of the case 21 (for example, a direction parallel to the y-axis in FIG. 5) and be arranged in series.

[0053] More specifically, the multiple battery cells 22 may include a first battery cell 23 located on one side of the case 21 in the longitudinal direction, and a second battery cell 24 located on the other side of the case 21 in the longitudinal direction.

[0054] The first battery cell 23 and the second battery cell 24 may extend parallel to the width direction of the housing 10, i.e., the longitudinal direction of the case 21. The second battery cell 24 may be disposed on one side of the first battery cell 23 with respect to the width direction of the housing 10, i.e., the longitudinal direction of the case 21, and may be aligned parallel to the first battery cell 23.

[0055] Therefore, the case 21 can accommodate the first battery cell 23 and the second battery cell 24 in an integrated manner.

[0056] The first battery cell 23 and the second battery cell 24 may each include at least one, and preferably a plurality of cells.

[0057] The number of cells included in each of the first battery cell 23 and the second battery cell 24 may be the same. When the first battery cell 23 includes a plurality of cells, the plurality of cells included in the first battery cell 23 may be stacked in the width direction of the case 21 (e.g., a direction parallel to the x-axis in FIG. 5 ). Similarly, when the second battery cell 24 includes a plurality of cells, the plurality of cells included in the second battery cell 24 may be stacked in the width direction of the case 21.

[0058] By arranging the multiple battery cells 22 in series, the length of the case 21 of the battery unit 20 can be increased. Thus, as described above, both ends of the case 21 can be brought close to both side portions 13 of the housing 10, and the rigidity of the case 21 can increase the structural rigidity that resists bending of the battery pack 1 in the width direction.

[0059] In addition, by arranging the multiple battery cells 22 in series, the width of the case 21 of the battery unit 20 can be reduced compared to the case where the multiple battery cells 22 are stacked in parallel. Thus, the number of battery units 20 stacked in the housing 10 increases, and the density of the case 21 in the longitudinal direction of the housing 10 can be increased. Therefore, the structural rigidity of the battery pack 1 that resists bending in the longitudinal direction can be increased due to the rigidity of the case 21 of the multiple battery units 20.

[0060] 1 to 3, the battery pack 1 may further include an attachment member 50 provided on the bottom portion 14 of the housing 10 to which the plurality of battery units 20 are attached. The plurality of battery units 20 may be attached to the housing 10 with the attachment member 50 provided on the bottom portion 14 of the housing 10.

[0061] For example, the attachment member 50 may be a resin applied to the bottom surface portion 14 of the housing 10. However, the configuration of the attachment member 50 is not limited to this.

[0062] By using the attachment member 50, the multiple battery units 20 can be firmly attached within the housing 10 without the need for a separate mechanical fastener.

[0063] The attachment member 50 may be provided so as to avoid the inlet 31 of the vent passage 30 described below. Therefore, the attachment member 50 may not hide the inlet 31 of the vent passage 30.

[0064] More specifically, the bottom surface 14 of the housing 10, more specifically, the inner bottom surface of the housing 10, may include a first region (A1) provided with the attachment member 50 and a second region (A2) in which the inlet 31 is formed. In Fig. 3, "A1" and "50" indicate the same point, but a person skilled in the art can easily understand the first region (A1) included in the bottom surface 14 of the housing 10 and the attachment member 50 located on the first region (A1).

[0065] Each second area (A2) may be formed to be long in the longitudinal direction of the housing 10. In each second area (A2), a plurality of inlets 31 spaced apart at regular intervals in the longitudinal direction of the housing 10 may be formed.

[0066] The second region (A2) may be provided in a plurality of regions spaced apart from each other in the width direction of the housing 10. For example, a pair of second regions (A2) may be provided.

[0067] The plurality of inlets 31 formed in any one of the second regions (A2) and the plurality of inlets 31 formed in the other one of the second regions (A2) may be positioned to correspond to each other in the width direction of the housing 10.

[0068] The first region (A1) may be divided into a plurality of regions by a plurality of second regions (A2). For example, the first region (A1) may include a center region located between a pair of second regions (A2) and a pair of side regions located outside the pair of second regions (A2).

[0069] However, the shapes of the first region (A1) and the second region (A2) are not limited to this, and it is of course possible for an attachment member 50 to be provided between at least some of the multiple inlets 31. In this case, the length of the second region (A2) in the longitudinal direction of the housing 10 may be shortened, and the multiple regions included in the first region (A1) may be connected to each other.

[0070] The first area (A1) may be larger than the second area (A2). Preferably, the area of ​​the first area (A1) may be three times or more larger than the area of ​​the second area (A2). Thus, multiple battery units 20 can be firmly attached to the housing 10.

[0071] FIG. 6 is a plan view showing vent channels of a battery pack according to one embodiment of the present invention, and FIG. 7 is a cutaway view showing the inlet, first channel, and second channel of FIG.

[0072] A vent hole 26 through which gas generated in the battery cell 22 is discharged may be formed in the bottom surface of the case 21 of each battery unit 20. If the battery cell 22 explodes or a fire occurs and the pouch is damaged, the gas generated in the battery cell 22 may leak into the case 21, and the gas may be discharged through the vent hole 26 formed in the case 21.

[0073] A plurality of vent holes 26 may be formed in a bottom surface of the case 21 of each battery unit 20. The plurality of vent holes 26 may be spaced apart in the longitudinal direction of the case 21.

[0074] More specifically, the multiple vent holes 26 may include a first vent hole 26a facing the first battery cell 23 in the battery unit 20 and a second vent hole 26b facing the second battery cell 24.

[0075] Therefore, when gas leakage occurs in one of the battery cells 22 among the plurality of battery cells 22 arranged in series, the gas can be quickly discharged to the vent hole 26 closest to the one battery cell 22.

[0076] A vent passage 30 communicating with the first vent hole 26a and the second vent hole 26b may be provided in the bottom surface portion 14 of the housing 10. The gas discharged to the first vent hole 26a and / or the second vent hole 26b may be discharged to the outside of the housing 10 through the vent passage 30.

[0077] More specifically, the vent flow passage 30 may include an inlet 31 formed in the inner bottom surface 14a of the housing 10 and facing the first vent hole 26a or the second vent hole 26b, and a first flow passage 32 communicating with the inlet 31 and positioned between the inner bottom surface 14a and the outer bottom surface 14b of the housing 10. The vent flow passage 30 may further include a second flow passage 33 extending along the side portion 13 of the housing 10 and communicating with the first flow passage 32. The vent flow passage 30 may further include an outlet 34 located at an end of the second flow passage 33 and through which gas is discharged to the outside around the housing 10.

[0078] The inlet 31 may be formed in the bottom surface portion 14 of the housing 10, more specifically, in the inner bottom surface 14a. The inlet 31 may be located in a second area (A2) of the inner bottom surface 14a of the housing 10 (see FIG. 3).

[0079] The inlet 31 may be adjacent to and face the vent hole 26 of the battery unit 20. Therefore, gas discharged to the vent hole 26 may immediately flow into the inlet 31.

[0080] The inlet 31 may be formed to penetrate from the inner bottom surface 14a of the housing 10 to a first flow passage 32, which will be described later.

[0081] The multiple inlets 31 may be arranged to form a predetermined matrix in the longitudinal direction and width direction of the housing 10. For example, as shown in Fig. 6, the multiple inlets 31 may form two rows in the longitudinal direction of the housing 10 (e.g., a direction parallel to the x-axis in Fig. 6) and eight columns in the width direction of the housing 10 (e.g., a direction parallel to the y-axis in Fig. 6).

[0082] The multiple inlets 31 positioned on the same line in the width direction of the housing 10 may face the multiple vent holes 26 formed in any one of the battery units 20.

[0083] The first flow passage 32 may be located within the bottom portion 14 of the housing 10. More specifically, the first flow passage 32 may be located between the inner bottom surface 14a and the outer bottom surface 14b of the housing 10.

[0084] A plurality of first flow paths 32 may be provided in parallel to each other. The plurality of first flow paths 32 may be formed to extend in parallel to the battery units 20. The plurality of first flow paths 32 may be provided corresponding to the plurality of battery units 20. Thus, it is possible to prevent the gas discharged from the vent hole 26 of one battery unit 20 from flowing into the vent hole 26 of another battery unit 20 while passing through the first flow path 32, or to prevent the temperature of the other battery units 20 from increasing due to the heat of the gas.

[0085] The second flow passage 33 may extend along the side surface portion 13 of the housing 10. The second flow passage 33 may be connected to a plurality of the first flow passages 32. More specifically, the second flow passages 33 may be provided in a pair extended along both side surface portions 13 of the housing 10, and both ends of each of the first flow passages 32 may be connected to the pair of second flow passages 33.

[0086] In one embodiment of the present invention, the second flow passage 33 may be formed within an extension 19 that extends outward from the side portion 13 of the housing 10 .

[0087] Therefore, compared to when the second flow path 33 is formed in the bottom portion 14 of the housing 10, it is possible to prevent the temperature of the other battery units 20 from increasing due to the heat of the gas passing through the second flow path 33, etc.

[0088] In other words, due to the configuration of the first flow path 32 and the second flow path 33, when a fire or the like occurs in one of the battery units 20 and gas is discharged, thermal propagation between multiple battery units 20 can be minimized.

[0089] The outlet 34 may be located at an end of the second flow passage 34. The outlet 34 may be an opening facing the outside of the housing 10. The outlet 34 may face outward around the housing 10. A pair of outlets 34 may be formed for each second flow passage 34. The pair of outlets 34 may be located at both ends of the second flow passage 34.

[0090] The second flow paths 33 are formed along both side portions of the housing 10, and a pair of outlets 34 are formed in each of the second flow paths 33, thereby shortening the path that gas discharged from any one of the battery units 20 takes to be discharged outside the housing 10.

[0091] Meanwhile, the bottom surface portion 14 of the housing 10 may be provided with a refrigerant flow path 40 that is separated from the vent flow path 30. More specifically, the refrigerant flow path 40 may be located between the inner bottom surface 14a and the outer bottom surface 14b of the housing 10 and may be separated from the first flow path 32.

[0092] The refrigerant flow path 40 may be located above the first flow path 32. More specifically, the refrigerant flow path 40 may be formed to pass between the first flow path 32 and the inner bottom surface 14a of the housing 10. That is, the distance between the refrigerant flow path 40 and the multiple battery units 20 may be closer than the distance between the first flow path 32 and the multiple battery units 20. In addition, the refrigerant flow path 40 may be formed to intersect with the first flow path 32.

[0093] Therefore, it is possible to reduce the influence of the heat of the gas passing through the first flow path 32 on the plurality of battery units 20. In addition, the battery units 20 can be quickly heated by the coolant (eg, water) passing through the coolant flow path 40.

[0094] FIG. 8 is a plan view showing vent channels of a battery pack according to another embodiment of the present invention, and FIG. 9 is a cutaway view showing the inlet, the first channel, and the second channel of FIG.

[0095] In this embodiment, the second flow passage 33 may be formed in the side portion 13 of the housing 10. This increases the design freedom of the housing 10. For example, a separate extension portion may be detachably fastened to the housing 10.

[0096] FIG. 10 is a perspective view of a battery pack according to a comparative example, FIG. 11 is a plan view of the battery pack according to the comparative example, and FIG. 12 is an enlarged view of the fastening portion and its surroundings shown in FIG.

[0097] The length of the multiple battery units 20′ included in the battery pack according to the comparative example may be less than half the distance between both side portions 13 of the housing 10. Therefore, a pair of battery units 20′ may be arranged in the width direction of the housing 10.

[0098] This is because the multiple battery cells included in each battery unit 20′ are stacked in parallel rather than in series, i.e., the multiple battery cells included inside the battery unit 20′ may be stacked in the longitudinal direction of the housing 10 (e.g., a direction parallel to the x-axis in FIG. 10).

[0099] In addition, in order to reinforce the rigidity of the battery pack, the housing 10 may be provided with a reinforcing portion 15 disposed between some of the plurality of battery units 20' and other portions thereof.

[0100] The reinforcing portion 15 may have a cross beam shape. More specifically, the reinforcing portion 15 may include a first reinforcing portion 16 and a plurality of second reinforcing portions 17 extending in a direction intersecting with the first reinforcing portion 16.

[0101] The first reinforcing portion 16 may extend in the longitudinal direction of the housing 10 and cross between a battery unit 20' located on one side in the width direction of the housing 10 and a battery unit 20' located on the other side in the width direction of the housing 10. Each second reinforcing portion 17 may be connected to the first reinforcing portion 16, extend in the width direction of the housing 10, and cross between adjacent battery units 20'.

[0102] Furthermore, in order to mount each battery unit 20' inside the housing 10, each battery unit 20' may be provided with a fastening portion 29 that mechanically fastens a case of the battery unit 20' inside the housing 10. For example, the fastening portion 29 may be a fastening boss provided at a corner of the case of the battery unit 20'.

[0103] The housing 10 may have a fastening hole (not shown) inside to which the fastening portion 29 corresponds.

[0104] However, in the battery pack according to the comparative example, the reinforcing portion 15 and the fastening portion 29 occupy a part of the space within the housing 10, so that the space utilization rate and the energy density of the battery pack are reduced.

[0105] Meanwhile, the housing 10 of the battery pack 1 according to the embodiment of the present invention may not be provided with a reinforcing portion disposed between one part of the plurality of battery units 20 (see FIGS. 1 and 2). This can increase the energy density of the battery pack 1. In this regard, as described above, due to the self-rigidity and structural rigidity of the case 21 of the plurality of battery units 20, the rigidity of the battery pack 1 can be maintained high even without a separate reinforcing portion, unlike the comparative example.

[0106] Furthermore, the housing 10 according to the embodiment of the present invention may not be provided with a fastening portion for mechanically fastening the case 21 of the battery unit 20 (see FIGS. 1 and 2) inside the housing 10. This can increase the energy density of the battery pack 1. In relation to this, as described above, the attachment member 50 provided on the bottom portion 14 of the housing 10 allows a plurality of battery units 20 to be stably attached inside the housing 10.

[0107] The above description is merely an illustrative example of the technical concept of the present invention, and various modifications and variations are possible by those having ordinary knowledge in the technical field to which the present invention pertains, without departing from the essential characteristics of the present invention.

[0108] Therefore, the embodiments disclosed in the present invention are intended to explain, not to limit, the technical idea of ​​the present invention, and such embodiments do not limit the scope of the technical idea of ​​the present invention.

[0109] The scope of protection of the present invention should be interpreted according to the following claims, and all technical ideas within the scope equivalent thereto should be interpreted as being included in the scope of the present invention. [Explanation of symbols]

[0110] 1 Battery Pack 10. Housing 11 Front part 12 Back part 13 Side part 14 Bottom part 14a Inner bottom 14b Outer bottom 19 Extension 20 Battery Unit 21 cases 22 Battery Cells 23 Cell 1 24 Cell 2 26 Vent Hole 30 Vent passage 31 Inlet 32 First Channel 33 Second Flow Path 34 Outlet 40 Coolant flow path 50 Adhesive material

Claims

1. A battery pack comprising: Housing and a plurality of battery units disposed within the housing; The battery unit includes: A first battery cell extending parallel to a width direction of the housing; a second battery cell disposed on one side of the first battery cell in a width direction of the housing and aligned parallel to the first battery cell; a case that is a rigid body extending parallel to a width direction of the housing and collectively houses the first battery cell and the second battery cell; In the case, a first vent hole toward the first battery cell; a second vent hole facing the second battery cell; The housing is provided with a vent passage communicating with the first vent hole and the second vent hole. Battery pack.

2. The cases of the plurality of battery units are stacked so as to be in contact with or adjacent to each other.

2. The battery pack of claim 1.

3. The length of the case is greater than half the distance between the two side surfaces of the housing.

2. The battery pack of claim 1.

4. The housing does not include a reinforcing portion disposed between some of the plurality of battery units and other parts of the plurality of battery units.

2. The battery pack of claim 1.

5. The housing is not provided with a fastening portion that mechanically fastens the case to the inside of the housing.

2. The battery pack of claim 1.

6. The first vent hole and the second vent hole are formed in a bottom surface of the case, The vent passage is provided in a bottom surface portion of the housing.

2. The battery pack of claim 1.

7. The vent passage is an inlet formed on an inner bottom surface of the housing and facing the first vent hole or the second vent hole; a first flow passage communicating with the inlet and located between an inner bottom surface and an outer bottom surface of the housing; 7. The battery pack of claim 6, comprising:

8. The first flow path extends parallel to the battery unit.

8. The battery pack according to claim 7.

9. The vent passage is A second flow passage extending along a side surface of the housing and communicating with the first flow passage.

8. The battery pack according to claim 7.

10. the bottom surface of the housing includes an extension portion that extends outwardly from the side surface of the housing, The second flow path is formed in the extension portion.

10. The battery pack of claim 9.

11. The second flow path is formed in a side portion of the housing.

10. The battery pack of claim 9.

12. The vent passage is an outlet located at an end of the second flow path, through which gas is discharged to the outside around the housing; 10. The battery pack of claim 9.

13. The inner bottom surface of the housing is a first region including an attachment member to which the plurality of battery units are attached; a second region in which the inlet is formed; 8. The battery pack of claim 7, comprising:

14. The housing is provided with a refrigerant flow path located between an inner bottom surface and an outer bottom surface of the housing and partitioned from the first flow path.

8. The battery pack according to claim 7.

15. The refrigerant flow path is located above the first flow path.

15. The battery pack of claim 14.

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