Battery pack

Abstract

The present invention allows gas within a battery pack to be easily discharged to the outside of the battery pack by utilizing gas channels formed in the side wall frames of the upper pack housing and the lower pack housing. Accordingly, the propagation of high-temperature gas or flame between battery cells housed in the battery pack can be delayed. In addition, by introducing a gasket to prevent gas and flame propagation between battery assemblies, and by including a unit frame assembly composed of a unit frame in the lower pack housing, a battery pack is provided that allows the bottom surface area of ​​the battery pack to be freely expanded.

Description

Technology Field

[0001] The present invention relates to a battery pack that accommodates a plurality of battery assemblies.

[0002] More specifically, this invention relates to a battery pack capable of efficiently discharging venting gas generated within the battery pack to the outside of the battery pack. Background Technology

[0004] Battery packs applied to electric vehicles and the like have a structure in which multiple battery modules, each containing multiple secondary batteries, are connected in series or parallel to obtain high output. Furthermore, the secondary batteries include positive and negative current collectors, separators, active materials, electrolytes, etc., and are capable of repeated charging and discharging through electrochemical reactions between the components.

[0005] Recently, as battery capacity has increased, the size of battery cells housed within battery packs has become larger or the number of cells has increased. Consequently, this increase in capacity leads to a rise in the explosive power of the battery pack, thereby increasing the risk associated with explosions. For instance, if a single battery cell ignites and generates high-temperature gas or flames, the propagation of these substances to adjacent cells accelerates; therefore, a structure capable of delaying or preventing this spread is required.

[0007] Meanwhile, if the type or size of battery cells changes, or if it is necessary to change the capacity of the battery pack by increasing or decreasing the number of battery cells, the size or specifications of the battery pack housing the said cells must be changed. However, conventional battery packs had fixed specifications for the base plate housing the battery cells or modules, so the size or area of ​​the battery pack could not be freely changed. In particular, it was difficult to respond when it was necessary to manufacture a wide variety of battery packs with new specifications and capacities depending on the type of newly released automobile. In other words, conventional battery packs had a problem in that the degree of freedom for design changes was significantly reduced.

[0009] Therefore, the development of technology capable of delaying or preventing gas and flame propagation within a battery pack is desired.

[0010] In addition, there is a desire to develop a technology that can freely change the size or area depending on the type of battery cell or the vehicle in which the cell is used, while simplifying the structure to improve energy density. Prior art literature

[0012] Korean Patent Publication No. 10-2022-0014027 The problem to be solved

[0013] The present invention aims to solve the above-mentioned problems by providing a battery pack capable of delaying the propagation of high-temperature gas or flames between battery cells by efficiently discharging high-temperature gas generated within the battery pack. means of solving the problem

[0015] To solve the above problem, a battery pack according to one embodiment of the present invention comprises: a plurality of battery assemblies; a lower pack housing having an open upper surface and accommodating the plurality of battery assemblies; and an upper pack housing coupled to the open upper surface of the lower pack housing, wherein the upper pack housing has a gas inlet into which gas generated within the battery pack is introduced and a first gas channel communicating with the gas inlet, and the lower pack housing includes a side wall frame having a second gas channel communicating with the first gas channel and a gas outlet communicating with the second gas channel to discharge the gas to the outside of the battery pack.

[0016] A rim portion of the upper pack housing is coupled to a side wall frame of the lower pack housing, a first venting hole communicating with the first gas channel is formed at the lower part of the rim portion, and a second venting hole communicating with the first venting hole and also communicating with the second gas channel can be formed at the upper part of the side wall frame.

[0017] The upper pack housing may include a lower plate frame having the gas inlet formed therein, and an upper plate frame coupled to the lower plate to form a first gas channel between it and the lower plate.

[0018] Alternatively, the upper pack housing may be configured as a hollow structure having a first gas channel formed inside, and a plurality of gas inlets communicating with the first gas channel may be formed on the lower surface.

[0019] The above side wall frame is a hollow structure with a second gas channel formed inside, and the gas outlet may be formed at least one along the outer wall of the side wall frame.

[0020] The first gas channel and the second gas channel may be oriented in different directions from each other.

[0021] A venting mechanism may be installed at the gas outlet of the above-mentioned side wall frame, the venting mechanism comprising a gas sealing member that deforms at a predetermined pressure and / or a predetermined temperature or higher to open the gas outlet to the outside.

[0022] The upper pack housing and the side wall frame are made of different materials, and the material of the upper pack housing may have higher heat resistance than the material of the side wall frame.

[0023] In addition, a plurality of partitions are installed in the bottom portion of the lower pack housing, positioned between each battery assembly, and the side wall frame can be connected along the perimeter of the bottom portion.

[0024] The above bulkhead may have a height equal to or greater than the height of the battery assembly.

[0025] The distance between adjacent bulkheads may be smaller than the width of each battery assembly.

[0026] The battery assembly may further include two or more rows arranged along the extension direction of the partitions between adjacent partitions, and two or more partitions installed at a predetermined interval in the arrangement direction of the battery assembly corresponding to the number of rows of the battery assembly, and a center frame that extends perpendicularly to the arrangement direction of the battery assembly and is installed at a predetermined interval between the partitions.

[0027] The battery pack may further include a gasket that is coupled to the upper surface of the side wall frame of the lower pack housing and the bulkhead to isolate each battery assembly accommodated in the lower pack housing together with the bulkhead.

[0028] The above gas inlets can each be formed on the lower surface of the upper pack housing located on the upper part of the isolated battery assembly.

[0029] The lower pack housing may include a unit frame assembly formed by joining the unit frames in a row along the lateral direction by successively joining the lower end of the bulkhead of one unit frame's base plate to the lateral end of a subsequent unit frame's base plate; and a side wall frame joined along the perimeter of the unit frame assembly. Effects of the invention

[0031] According to the present invention, high-temperature gas generated within the battery pack can be discharged toward the side wall frame through the upper pack housing, thereby effectively delaying the propagation of high-temperature gas or flame between battery cells.

[0032] Furthermore, according to one embodiment of the present invention, by implementing a cell-to-pack structure that directly accommodates battery cells without a module housing, processes and costs associated with the production and assembly of module components can be eliminated. In addition, by eliminating assembly tolerances required for module installation, making the space within the pack more compact in the height direction, and reducing the weight of the battery pack, the energy density occupied by the same battery pack space can be further improved.

[0033] Furthermore, according to an exemplary embodiment of the present invention, the size and area of ​​the battery pack can be freely changed by increasing or decreasing the number of assembled unit frames that can be used as common parts. Accordingly, the size of the battery pack can be changed according to the required specifications, thereby significantly improving the design freedom of the battery pack. In addition, the unit frames can be standardized or made common parts to lower the production cost of the parts. Brief explanation of the drawing

[0035] Figure 1 is a schematic diagram showing the structure of a conventional battery module. Figure 2 is a schematic diagram of a conventional battery pack. Figure 3 is a schematic cross-sectional view of a conventional battery pack structure. FIG. 4 is a partially exploded perspective view of a battery pack of one embodiment of the present invention. FIG. 5 is a schematic diagram of a battery assembly accommodated in a battery pack of the present invention. Fig. 6 is an exploded view of the pack housing of the battery pack of Fig. 4. FIG. 7 is a perspective view showing a gas venting path according to the battery pack of FIG. 4. Figure 8 is a cross-sectional view showing a gas venting path according to the battery pack of Figure 4. FIG. 9 is a schematic diagram comparing a conventional battery pack and a battery pack of the present invention. FIG. 10 is a partially exploded perspective view of a battery pack of another embodiment of the present invention. FIG. 11 is a perspective view of the battery pack of FIG. 10 of the present invention. FIG. 12 is a cross-sectional view showing a gas venting path according to the battery pack of FIG. 10. FIG. 13 is a partially exploded perspective view of a battery pack of another embodiment of the present invention. Fig. 14 is an exploded view of the pack housing of the battery pack of Fig. 13. FIG. 15 is a schematic diagram showing the assembly process of a unit frame assembly, which is a component of the battery pack of FIG. 13. FIG. 16 is a cross-sectional view showing a gas venting path according to the battery pack of FIG. 13. Specific details for implementing the invention

[0036] The present invention will become more apparent from the detailed description of preferred embodiments of the invention with reference to the accompanying drawings. The embodiments described herein are illustrative for the purpose of facilitating an understanding of the invention, and it should be understood that the present invention may be implemented in various modified forms different from the embodiments described herein. Furthermore, to aid in understanding the invention, the accompanying drawings are not drawn to actual scale, and the dimensions of some components may be exaggerated.

[0038] The present invention will be described in detail below.

[0040] (First embodiment)

[0041] FIG. 1 is a schematic diagram showing the structure of a conventional battery module, FIG. 2 is a schematic diagram of a conventional battery pack, and FIG. 3 is a schematic cross-sectional view of a conventional battery pack structure.

[0042] As illustrated in FIG. 1, a conventional battery module (10) is provided with a module housing (12: 12A, 12B) that accommodates a plurality of battery cells (11), and a front plate (13) and a rear plate (14) that cover the front and rear ends of the module housing. Additionally, a heat transfer member (1) made of a thermally conductive adhesive or the like is located between the battery cells and the module housing (see FIG. 3).

[0043] FIGS. 2 and 3 show that a plurality of such battery modules (10) are installed in the pack housing (21) of a battery pack (20). Each battery module (10) is installed between partitions (22) provided on the base plate (23) of the pack housing (21). Additionally, a heat transfer member (1'), made of a thermally conductive adhesive or the like, is additionally disposed between the battery module and the base plate (23) on which the module is mounted, and a cooling plate (24) is disposed on the lower part of the base plate (23).

[0044] FIG. 4 is a partially exploded perspective view of a battery pack according to one embodiment of the present invention, FIG. 5 is a schematic diagram of a battery assembly accommodated in the battery pack of the present invention, FIG. 6 is an exploded view of the pack housing of the battery pack of FIG. 4, and FIG. 7 and FIG. 8 are a perspective view and a cross-sectional view showing a gas venting path according to the battery pack of FIG. 4.

[0045] In this specification, terms indicating directions such as front, back, left, right, up, and down may vary depending on the position of the observer or the arrangement of the object. However, for the convenience of explanation, in this specification, directions such as front, back, left, right, up, and down are distinguished and indicated based on the view from the direction of the arrow (F) in FIG. 4.

[0047] A battery pack according to one embodiment of the present invention comprises: a plurality of battery assemblies; a lower pack housing having an open upper surface and accommodating the plurality of battery assemblies; and an upper pack housing coupled to the open upper surface of the lower pack housing, wherein the upper pack housing has a gas inlet into which gas generated within the battery pack is introduced and a first gas channel communicating with the gas inlet, and the lower pack housing includes a side wall frame having a second gas channel communicating with the first gas channel and a gas outlet communicating with the second gas channel to discharge the gas to the outside of the battery pack.

[0048] A battery pack according to one embodiment of the present invention may include a plurality of battery assemblies, a lower pack housing, and an upper pack housing.

[0049] The battery assembly described above may include a plurality of battery cells. The battery cells may be classified into pouch-type battery cells and can-type battery cells depending on the shape of the case. Can-type battery cells may include cylindrical battery cells and prismatic battery cells. Additionally, each of the battery cells includes an electrode assembly embedded in the battery case. The electrode assembly includes a positive electrode, a negative electrode, and a separator interposed between the positive and negative electrodes. The electrode assembly may be classified into a jelly-roll type and a stack type depending on the assembly form. A jelly-roll type electrode assembly is formed by winding a positive electrode, a negative electrode, and a separator interposed between them. A stack type electrode assembly is formed by sequentially stacking a positive electrode, a separator, and a negative electrode.

[0050] The above battery assembly may be a battery module (10) having a module housing that accommodates a plurality of battery cells as shown in FIG. 1. The battery module may be in a form in which a part of the module housing that accommodates the battery cells is removed. For example, to simplify the structure, a battery module having a module housing in which the upper housing (12A) is removed or the bottom part of the lower housing (12B) is removed may also be a battery assembly of the present invention.

[0051] Alternatively, as shown in FIGS. 4 and 5, a battery cell stack in which the module housing itself covering the upper, lower, left, and right sides of a plurality of battery cells is removed can also be a battery assembly.

[0052] In the embodiment disclosed in FIGS. 4 and 5, a battery cell stack, i.e., a cell stack unit unit (100), is applied as the battery assembly, wherein a plurality of battery cells (110) are stacked. The cell stack unit unit (100) may be configured by stacking a plurality of battery cells (110). The battery cells (110) are stacked so that their sides are in contact with each other, and the sides of adjacent battery cells (110) may be fixed together using double-sided tape. Alternatively, the stacked plurality of battery cells (110) may be wrapped, for example, with a band (111) made of synthetic resin to form a single battery assembly. In this embodiment, the cell stack unit unit (100) may be configured by stacking in the left-right direction (or horizontal direction), as shown in FIG. 4. However, it is also possible to configure the battery cells (110) to be stacked in the up-down direction (height direction) as needed.

[0054] A busbar assembly (120) may be coupled to the electrode leads at the front and rear ends of the cell stack unit (100). The busbar assembly (120) may be equipped with a busbar (121) that electrically connects battery cells or a terminal busbar (122) that can be connected to an external power source. The number of battery cells (110) stacked in one cell stack unit (100) may be, for example, 2, 4, 6, or 8, but is not limited thereto.

[0055] The cell stack unit (100) may include at least one buffer pad (130) between the stacked battery cells (110) (see FIG. 5(b)). The buffer pad is intended to absorb the expansion of the battery cells (110) due to swelling.

[0056] In this embodiment, although a pouch-type battery cell is used as the battery cell (110) as an example, it is not limited thereto, and it is also possible to configure the battery assembly with, for example, a can-type battery cell.

[0058] As illustrated in FIG. 4, the plurality of battery assemblies (e.g., cell stack unit (100)) are accommodated in a lower pack housing (200) with an open top surface.

[0059] The upper pack housing (300) is coupled to the open upper surface of the lower pack housing (200). The upper pack housing (300) may be, for example, a pack cover assembly in which a pack cover and associated parts are combined. The upper pack housing (300) may be formed in a flat shape. However, in order to form a space on the battery assembly, the part corresponding to the battery assembly may be convexly protruding and the inner surface thereof may be formed concavely.

[0060] The upper pack housing (300) of the present invention is provided with a gas inlet (321) and a gas channel communicating with the gas inlet (321) in order to discharge gas generated within the battery pack to the outside.

[0061] High-temperature gas generated within the battery pack (1000) rises from the battery assemblies and is mainly collected in the space between the lower pack housing (200) and the upper pack housing (300). However, the side wall frames constituting the lower pack housing (200) are made of a material with relatively low heat resistance, such as aluminum, for weight reduction. Therefore, if this high-temperature gas is discharged directly through the side wall frames, there is a possibility that the side wall frames may partially soften or melt, thereby damaging the structure of the lower pack housing (200). On the other hand, the upper pack housing (300) is made of a material that is relatively strong and has high heat resistance, such as steel, for the protection of the battery pack. Therefore, the upper pack housing (300) typically has higher heat resistance than the lower pack housing (200). In the present invention, a gas channel for discharging high-temperature gas is provided in the upper pack housing (300), which has such high heat resistance. Additionally, if a gas channel is formed in the upper pack housing, the gas accumulated in the space between the upper pack housing (300) and the lower pack housing (200) can be introduced directly into the upper pack housing (300). That is, since the high-temperature gas is introduced quickly into the upper pack housing (300) without remaining in the battery pack for a long time, the propagation of heat to other battery cells or battery assemblies can be delayed and the rise in temperature within the battery pack can be slowed down. Furthermore, since high-temperature gas has a strong tendency to rise, considering the flow tendency of the gas, it is advantageous to vent the gas through the gas channel of the upper pack housing (300) first rather than venting the gas through the lower pack housing (200).

[0062] Gas introduced through the gas inlet (321) of the upper pack housing (300) moves to the lower pack housing (200) through the gas channel and is discharged to the outside through the gas channel provided in the lower pack housing (200). In terms of gas flow, the gas channel of the upper pack housing (300) is referred to as the first gas channel (H1), and the gas channel of the side wall frame is referred to as the second gas channel (H2).

[0063] Referring to FIG. 8, a plurality of gas inlets (321) are formed on the lower surface of the upper pack housing (300). In order to quickly discharge the gas accumulated on the upper part of the battery assembly, it is preferable to install at least one gas inlet (321), preferably one per battery assembly. Additionally, if the position of the gas inlet (321) is provided at a position corresponding to the position of the battery assembly housed in the lower pack housing (200), the gas generated from each battery assembly can be easily vented. In particular, since high-temperature gas is generated in large quantities at the electrode lead portion of the battery cell (110), the gas inlet (321) can be formed at a position corresponding to the electrode lead of the battery cell (110) included in the battery assembly.

[0064] Additionally, the size or shape of the gas inlet (321) can be appropriately determined considering the ease of gas discharge. For example, the shape of the gas inlet (321) can be formed as an elongated slot extending in the direction of extension of the battery assembly. Also, its size can be formed large enough to correspond to the upper surface area of ​​the battery assembly. However, the number, location, shape, and size of the gas inlet (321) are not limited to those described above. For faster and easier gas venting, appropriate modifications can be made, for example, by uniformly distributing small gas inlets (321) on the lower surface of the upper pack housing (300), or by forming only a few long gas inlets across the battery pack on the lower surface.

[0065] The upper pack housing (300) can be manufactured as a hollow structure, for example, having a first gas channel (H1) formed inside. In this case, the gas inlet (321) formed on the lower surface can be connected to the first gas channel (H1) of the hollow structure.

[0066] An example of such an upper pack housing (300) is disclosed in FIG. 8. Referring to FIG. 8, the upper pack housing (300) includes a lower plate frame (320) having a gas inlet (321) formed therein, and an upper plate frame (310) coupled to the lower plate to form a first gas channel (H1) between it and the lower plate. A side plate frame may be provided between the upper plate frame (310) and the lower plate frame (320). Alternatively, it is possible to form the portions corresponding to the side plates by extending downward from both sides of the upper plate frame or by extending upward from both sides of the lower plate frame.

[0067] Since the first gas channel (H1) of the upper pack housing (300) is in communication with the second gas channel (H2) of the lower pack housing (200), a venting hole (first venting hole (320a)) communicating with the first and second gas channels (H2), respectively, can be formed on the lower surface of the upper pack housing (300). The upper pack housing (300) is joined by covering the open upper surface of the lower pack housing (200), that is, the upper surface of the rim portion (upper surface of the side wall frame (230)) of the lower pack housing (200). Accordingly, the first venting hole (320a) is also formed on the lower surface of the rim portion of the upper pack housing (300) corresponding to the upper surface of the side wall frame (230).

[0068] The arrangement direction of the first gas channel (H1), the location and number of the first venting holes (320a) are determined according to the location and number of the second gas channel (H2) and the second venting holes (231a, 232a) described later.

[0069] That is, among the four-sided sidewall frames (230) surrounding the battery assembly, the first gas channel (H1) extends toward the sidewall frame in which the second gas channel (H2) is formed, and the first venting hole (320a) can also be formed on the lower surface of the upper pack housing (300) that contacts the upper surface of the sidewall frame (230) in which the second gas channel (H2) is formed. When the second gas channel (H2) is formed in all four-sided sidewall frames, there is no particular restriction on the orientation of the first gas channel (H1). Additionally, the first venting hole (320a) can be formed at any location on the lower surface of the rim of the upper pack housing (300) that contacts the four-sided sidewall frames (230). Considering the efficiency of gas venting, it is preferable to form a first venting hole (320a) symmetrically connected to a second gas channel (H2) on the lower surface of both sides of the lower pack housing (200) connected to at least the first gas channel (H1). Accordingly, gas can move to both sides along the first gas channel (H1) of the upper pack housing (300) and be simultaneously discharged through the second gas channel (H2) of the side wall frames on both sides connected thereto.

[0070] Referring to FIG. 6, the lower pack housing (200) of the present embodiment is formed in a box shape with an open top by having a base plate (220) which is a bottom portion on which battery assemblies (e.g., battery module (10) or cell stack unit (100)) are seated, and side wall frames (230) installed along the edge of the base plate (220).

[0071] Specifically, the above side wall frames (230) may be composed of a front frame (231) and a rear frame (232) covering the front and rear of the battery assembly, and a first side frame (233) and a second side frame (234) covering the left and right of the battery assembly.

[0072] The base plate (220) may have a plate shape that extends in a horizontal direction. Here, the horizontal direction refers to the direction of the flat surface of the ground. The base plate (220) may be made of a metal material with excellent mechanical strength.

[0073] In addition, a front frame (231), a rear frame (232), and first and second side frames (233, 234) are respectively attached to the base plate (220). The joining method may be, for example, friction stir welding.

[0074] The front frame (231) may have a shape that is extended in the left-right direction and is erected in the height direction. The front frame (231) may have a front cover portion that extends in the height direction and a front plate portion that protrudes forward from the lower part of the front cover portion. The front plate portion may be fixedly connected to a structure such as a vehicle.

[0075] The rear frame (232) may have a shape that extends long in the left-right direction and is erected in the height direction. The rear frame (232) may be formed in the same or different shape as the front frame (231). The rear frame (232) is formed in the same shape as the front frame by having a rear cover portion that extends in the height direction and a rear plate portion that protrudes rearward from the lower part of the rear cover portion. The rear plate portion may be fixedly connected to a structure such as a vehicle.

[0076] The first and second side frames (233, 234) may have a shape that is extended in the front-rear direction. The side frames consist of a first side frame (233) that covers the left side of the battery assembly and a second side frame (234) that covers the right side. In the illustrated embodiment, the first and second side frames are configured in the form of flat plates. However, the side frames may also be configured in two parts, such as the front-rear frames (231, 232), a flat plate portion (side cover portion) that extends in the height direction and a flat plate portion (left plate portion, right plate portion) that protrudes in the left and right directions.

[0077] The base plate (220) and / or side wall frames (230) can be manufactured as hollow frames by extruding a metal material such as aluminum to form an internal empty space. By configuring the frames in a hollow form in this way, the weight of the battery pack can be reduced and energy efficiency increased. Additionally, by forming a rib-shaped reinforcing wall in the internal space, the mechanical strength of the frames can be maintained at a reliable level.

[0078] As illustrated in FIGS. 4 and 6, in the present invention, the side wall frame (230) may be formed as a hollow frame in which a gas channel is formed inside. That is, at least one of the front frame (231), rear frame (232), and first and second side frames (233, 234) constituting the side wall frame has a second gas channel (H1) formed inside. As described above, the second gas channel is in communication with the first gas channel (H1) provided by the upper pack housing (300). Since the second gas channel (H2) is in communication with the first gas channel (H1), the location of the second gas channel (H2) can also be determined according to the location of the first gas channel (H1). For example, if the first gas channel (H1) is extended in the front-rear direction and the first venting hole (320a) is formed on the lower surface of the rim portion of the upper pack housing (300) at both ends in the front-rear direction, the second gas channel (H2) can be formed in the front frame (231) and the rear frame (232). In this case, the second venting hole (231a, 232a), which communicates with the first venting hole (320a) and communicates with the second gas channel (H2), is formed on the upper surface of the front frame (231) and the rear frame (232).

[0079] If the first gas channel (H1) is extended in the front-rear direction and the first venting hole (320a) is formed on the lower surface of the rim portion of the upper pack housing (300) at both ends in the front-rear direction, the second gas channel (H2) can be formed in the front frame (231) and rear frame (232) that are extended in the left-right direction. In this case, the second venting holes (231a, 232a) are formed on the upper surface of the front frame (231) and rear frame (232) and are in communication with the first venting hole (320a) and the second gas channel (H2).

[0080] Additionally, if the first gas channel (H1) is extended in the left-right direction and the first venting hole (320a) is formed on the lower surface of the edge portion of the upper pack housing (300) at both ends in the left-right direction, the second gas channel (H2) can be formed in the first side frame (233) and the second side frame (233) that are extended in the front-rear direction.

[0082] In the above case, it is also possible to form a second gas channel (H2) in a side wall frame that is not directly connected through the first gas channel (H1), the first venting hole (320a), and the second venting hole (231a). For example, a case can be assumed in which all four side wall frames (230) are equipped with a second gas channel (H2) inside. That is, if the second gas channel (H2) provided in the four side wall frames (230) is connected along the circumference of the battery pack, the gas discharged from the first gas channel (H1) flows through the first and second venting holes to the second gas channel (H2) of the side wall frame that is directly connected to the second venting hole, and then flows to the second gas channel (H2) of the side wall frame that is not directly connected to the second venting hole, thereby extending the gas venting path. Of course, in this case, a predetermined communication passage may be provided in the joint of the opposing side wall frames so that the second gas channels (H2) of the adjacent side wall frames can communicate with each other.

[0083] As described above, when gas is discharged from the first gas channel (H1) of the upper pack housing (300) through the second gas channel (H2) of the lower pack housing (200), the following advantages are provided.

[0084] First, the high-temperature gas does not go directly to the side wall frame (230) which has low heat resistance, but first goes to the upper pack housing (300) which has high heat resistance, thus preventing damage to the side wall frame.

[0085] Second, gas can be discharged through a long path following the first gas channel (H1) and the second gas channel (H2). That is, safety is improved because high-temperature gas is not discharged directly outside the pack. In addition, in the process of passing through the long venting path following the upper pack housing (300) and the lower pack housing (200), incompletely combusted gas can be completely combusted or the temperature and pressure of the gas can be lowered. In this way, by making the venting path long, the state of the unstable gas can be stabilized, thereby reducing the risk of accidents caused by high-temperature gas.

[0087] To extend the gas venting path, the first gas channel (H1) and the second gas channel (H2) may be oriented in different directions. For example, when viewed from above, the first gas channel (H1) and the second gas channel (H2) may be oriented perpendicular to each other. In this case, for example, if high-temperature gas flowing in the front-rear direction through the first gas channel (H1) extended in the front-rear direction flows in the left-right direction through the second gas channel (H2) extended in the left-right direction through the first venting hole and the second venting hole, the gas venting path may be extended.

[0088] The above side wall frame (230) is provided with a gas outlet communicating with the second gas channel (H2).

[0089] At least one gas outlet may be formed along the outer wall of the side wall frame (230). The location of the gas outlet is also important to extend the gas venting path. That is, if the gas outlet is positioned far from the first and second venting holes, the gas introduced into the second gas channel (H2) through the second venting hole (231a) can be discharged through the gas outlet after flowing sufficiently through the second gas channel (H2). In addition, if multiple gas outlets are formed, the gas can be discharged more quickly to the outside of the battery pack. For example, as shown in FIG. 4, if gas outlets are formed on the outer walls located on both sides of the second gas channel (H2), the gas introduced from the upper pack housing (300) to the side wall frame (230) can be quickly discharged to the outside through the gas outlets on both sides.

[0091] Meanwhile, a venting mechanism (V1, V2) including a gas sealing member that deforms at a predetermined pressure and / or temperature or higher to open the gas outlet to the outside may be installed at the gas outlet.

[0092] The venting mechanism (V1, V2) may be equipped with a venting cap to prevent gas leakage from the gas outlet. Additionally, a gas sealing member may be installed within the gas outlet or the venting cap. The gas sealing member may be, for example, a sheet-shaped member that deforms at a predetermined pressure and / or a predetermined temperature or higher to open the gas outlet to the outside. For example, the gas sealing member may be a rupture sheet configured to rupture when the pressure of the venting gas exceeds a certain pressure. Alternatively, the sheet member may open the gas outlet by melting at a predetermined temperature or higher. To this end, the sheet member may be provided with a film or foam material that is susceptible to high temperatures.

[0093] Figures 7 and 8 illustrate a gas discharge path according to the present invention.

[0094] Referring to FIG. 7, it is disclosed that gas inside a battery pack, which flows into a first gas channel (H1) within an upper pack housing (300), is vented through a second gas channel (H2) formed within a front frame (231), which is a side wall frame of a lower pack housing (200), and through a venting mechanism (V1) installed on one side of the front frame. Since the first and second gas channels (H1, H2) are oriented perpendicularly to each other, it can be seen that the venting path is effectively extended within the same battery pack area. In addition, since the high-temperature venting gas does not go directly toward the side wall frame (230), the side wall frame can be protected and the temperature or pressure of the gas can be reduced during the long gas flow process.

[0095] FIG. 8 is a cross-sectional view along line B-B' of FIG. 4, showing the gas venting path in more detail. That is, it is clearly shown that gas generated in the battery assembly is introduced into the gas inlet (321) of the upper pack housing (300), flows through the first gas channel (H1) - first venting hole (320a) - second venting hole (231a) - second gas channel (H2), and is finally discharged through the gas outlet (venting mechanism part (V1, V2).

[0097] FIG. 9 is a simplified comparative diagram showing the structure of a conventional battery pack and the structure of a battery pack according to the present invention. A heat transfer member (R) may be provided on the bottom surface of the battery assembly (10, 100) and the lower pack housing (200). That is, the heat transfer member (R) may be provided on the base plate (220) forming the bottom portion of the lower pack housing (200). In order to ensure efficient heat transfer, this heat transfer member may be composed of at least some of a thermally conductive grease, a thermally conductive adhesive, a thermally conductive epoxy, and a heat dissipation pad, but is not limited thereto. Additionally, since the heat transfer member (R) performs the function of fixing the bottom surface of the battery assembly (10, 100) to the base plate (220), it may be configured to have an adhesive strength of a certain amount or more. Through the heat transfer member, heat is easily transferred to the base plate (220) equipped with a cooling channel, thereby enabling effective heat dissipation of the battery pack.

[0098] Additionally, the lower pack housing (200) may have a cooling channel (f) built into the bottom portion that is in direct contact with the battery assembly. That is, the base plate (220) may have a cooling channel (f) inside (see FIG. 12). For example, when the base plate (220) is extruded, a space may be formed inside the base plate (220) according to the direction of travel of the extruded member. The internal space may be divided into a plurality of hollow channels by partition walls. A separate cooling channel may be installed in at least one of these hollow channels, or the hollow channel itself may be used as a cooling channel.

[0099] Accordingly, the present invention can effectively cool the battery assembly by flowing a cooling fluid through a cooling channel (f) extending along the base plate (220). In addition, by making the base plate (220) a cooling-integrated structure, there is no need to install a separate cooling plate on the base plate (220) as in the conventional method. As a result, the height of the battery pack can be reduced, allowing the battery pack to be configured more compactly.

[0100] Additionally, the front frame (231) and the rear frame (232) may each be provided with a cooling channel communicating with the cooling channel of the base plate. In this case, one of the front frame (231) and the rear frame (232) may be provided with a refrigerant inlet and a refrigerant outlet communicating with the cooling channel. Alternatively, a refrigerant inlet may be formed in one of the front frame and the rear frame, and a refrigerant outlet in the other. Accordingly, the battery pack of the present invention can be designed with various cooling paths leading to the cooling channel of the front frame (231), the cooling channel of the base plate (220), and the cooling channel of the rear frame (232).

[0102] Additionally, a plurality of partitions may be installed in the bottom portion of the lower pack housing (200) between each battery assembly. Referring to FIG. 4, a plurality of partitions (210) are installed on the base plate (220) which is the bottom portion, and the side wall frame (230) is connected along the perimeter of the base plate (220).

[0103] In this embodiment, the partition wall (210) extends along the front-rear direction of the battery pack, but is not limited thereto and may also extend in the left-right direction.

[0104] The battery assembly is positioned between the above partitions (210). That is, the partitions (210) are positioned between adjacent battery assemblies. Accordingly, each battery assembly is partitioned and isolated by the partitions (210) in the left-right direction.

[0105] The above bulkhead (210) may be fastened to the base plate (220) by means of a fastening member or joined to the base plate (220) by means of welding, etc. The above bulkhead (210) may be made of a metal material such as aluminum to sufficiently support the side of the battery assembly. In this case, the weight of the bulkhead (210) can be reduced by manufacturing the bulkhead (210) into a hollow structure by means of extrusion processing, etc. The material of the above bulkhead (210) is not limited to a metal material, and may be formed of a synthetic resin material as long as rigidity can be secured. However, considering the situation where high-temperature gas or thermal runaway occurs due to the ignition of the battery cell (110), it may be preferable to form it of a metal material such as aluminum, steel, or stainless steel in terms of heat resistance.

[0106] The height of the above bulkhead (210) is formed to be at least equal to or higher than the height of the battery assembly so as to isolate adjacent battery assemblies.

[0107] The battery assembly can be accommodated in the lower pack housing (200) in close contact with the side of the partition wall (210). To this end, the distance between adjacent partition walls (210) can be formed to be smaller than the width of each battery assembly. In this case, to accommodate each battery assembly between the partition walls (210), the battery assembly must be compressed in the width direction (battery cell stacking direction) and inserted between the adjacent partition walls (210). In particular, when using a cell stack unit (100) as the battery assembly, it is preferable to form the distance between the partition walls to be smaller than the width of the cell stack unit (100). The cell stack unit (100) may include a cushioning pad (130) to absorb the expansion of the battery cell (110) due to swelling. Accordingly, when the cell stack unit (100) is compressed in the width direction, the cell stack unit (100) can be easily compressed by the compression of the cushioning pad.

[0109] On the other hand, if a battery module (10) is used as a battery assembly, the following problems may occur.

[0110] First, to assemble a battery module, a module housing, end plates, and various other auxiliary parts are required, which increases manufacturing costs.

[0111] In addition, as shown in FIG. 3(a), an assembly tolerance (G) inevitably occurs when installing the battery module (10) between the partitions (22) of the pack housing. Therefore, the number of battery cells installed in the battery pack is reduced by this assembly tolerance and the thickness of the battery module housing, so the energy density of the battery pack may be reduced.

[0112] In addition, as shown in FIG. 3(b), when the module housing (12) is installed on the battery cell (11) and the base plate (23) of the pack housing, two layers of heat transfer members (1, 1') are required above and below the module housing for heat transfer efficiency. Furthermore, due to the cooling plate (24) and the module housing (12), the height space of the battery pack increases and the weight of the pack increases. Because of this, not only does the manufacturing cost increase, but the energy density is further reduced due to the increase in the weight of the battery pack and the expansion of the installation space.

[0113] However, the above-described problem can be resolved when the cell stack unit (100) is used as a battery assembly.

[0114] In other words, by applying a cell stack unit, a so-called cell-to-pack structure is achieved where battery cells are directly housed within the pack housing without a module housing, thereby eliminating processes and costs associated with the production and assembly of module components.

[0115] In particular, by eliminating assembly tolerances required for module installation, making the space within the pack more compact in the height direction, and reducing the weight of the battery pack, the energy density occupied by the same battery pack space can be further improved.

[0116] Thus, according to the present invention, when accommodating a battery cell (110) in a battery pack, there is no need to have the assembly tolerance (G) required when using a conventional battery module. In addition, as described above, a cell stack unit (100) can be compressed and inserted between opposing partitions (210). Accordingly, the space of the battery pack can be reduced in the left-right direction, so more battery cells (110) can be installed in the same space, thereby improving energy density.

[0118] According to the arrangement of the above partitions (210), the arrangement of a plurality of battery assemblies accommodated within the lower pack housing (200) is determined. In this embodiment, the partitions (210) are arranged to extend long in the front-rear direction (X-direction), and the battery assemblies are arranged between the partitions (210) to extend long in the longitudinal direction. Additionally, the partitions (210) are arranged in parallel rows in the left-right direction (Y-direction) of the battery pack, and accordingly, the battery assemblies are also arranged in parallel rows along the left-right direction between adjacent partitions (210).

[0119] To increase the capacity of the battery pack, the battery assembly may be arranged in two or more rows along the extension direction of the partition (210) between adjacent partitions (210). In this embodiment, the battery assembly is arranged in two rows along the extension direction (front-rear direction) of the partition (210), but it is not limited thereto and may be arranged in three, four, or more rows. Theoretically, there is no limit to the number of front-rear rows of the battery assembly, but the number of required battery assemblies may be limited depending on the installation space of the vehicle and the required capacity of the battery pack.

[0120] In addition, two or more of the above partitions (210) may be installed at a predetermined interval in the arrangement direction of the battery assembly, corresponding to the number of rows of the battery assembly (100).

[0121] The above partition walls (210) are spaced apart at a predetermined interval in the front-rear direction. This is, firstly, to partition the battery assemblies in the front-rear rows to avoid interference with each other. Secondly, it is to install a reinforcing member capable of reinforcing the structural rigidity of the battery pack in the gap between the spaced partition walls (210). In this embodiment, a center frame (250) is installed as a reinforcing member, extending perpendicularly to the arrangement direction of the battery assemblies. Specifically, the center frame (250) is installed in the gap between the partition walls (210).

[0122] As described above, according to an exemplary embodiment, the battery assembly (cell stack unit unit (100)) is installed directly in close contact between the partitions (210) of the lower pack housing (200), thereby having a cell-to-pack structure, which overcomes the disadvantages of installing a battery module in a battery pack. In addition, high-temperature gas inside the battery pack can be rapidly discharged to the outside through the gas channels of the upper pack housing (300) and the lower pack housing (200), thereby delaying the propagation of high-temperature gas or flames inside the battery pack to adjacent battery assemblies. Accordingly, the safety of the battery pack is significantly improved.

[0123] Meanwhile, a portion of the battery pack may accommodate an electrical component assembly (not shown) without installing a battery assembly. The electrical component assembly may accommodate relay devices, current sensors, fuses, a BMS, an MSD (Manual Service Disconnector), etc. Such electrical component assemblies may be packaged within the battery pack together with the battery assembly so as not to be exposed to the outside.

[0125] (Second embodiment)

[0126] FIG. 10 is a partially exploded perspective view of a battery pack of another embodiment of the present invention, FIG. 11 is a perspective view of the battery pack of FIG. 10 of the present invention, and FIG. 12 is a cross-sectional view showing a gas venting path according to the battery pack of FIG. 10.

[0127] The battery pack (2000) of the present embodiment further includes a gasket (400) coupled to the upper surface of the side wall frame (230) of the lower pack housing (200) and the partition wall (210) to isolate each battery assembly accommodated in the lower pack housing (200) together with the partition wall (210).

[0128] Since other components besides the gasket (400) are the same as those in the first embodiment, a detailed description of the components identical to those in the first embodiment is omitted.

[0129] In this embodiment, a gasket (400) is installed between the upper pack housing (300) and the lower pack housing (200).

[0130] As shown in FIG. 10, the gasket (400) may be provided with an outer frame (410) and a plurality of isolation frames (420) that are extended and installed parallel to each other inside the outer frame (410).

[0131] The outer frame (410) forms the periphery of the gasket (400) and is a part that is connected to the upper surface of the side wall frame (230) of the lower pack housing (200) when the gasket (400) is connected to the lower pack housing (200). That is, the outer frame (410) is connected to the upper surface of the side wall frames (front and rear frames (231, 232), first and second side frames (233, 234)) of the lower pack housing (200). As the outer frame (410) is connected to the upper surface of the side wall frames and the upper pack housing (300) is connected to the upper part of the gasket (400), the periphery of the battery pack can be hermetically sealed. However, if the outer frame (410) covers the entire upper surface of the side wall frame, communication between the second gas channel (H2) of the lower pack housing (200) and the first gas channel (H1) of the upper pack housing (300) can be blocked. Accordingly, as shown in FIGS. 10 and 12, a through passage (411) can be formed in a part of the outer frame (410) of the gasket (400). That is, a through passage (411) communicating with the first and second venting holes can be formed in the joint of the outer frame facing the first venting hole (320a) and the second venting hole (231a). Accordingly, sealing by the gasket (400) can be achieved without obstructing the gas flow.

[0132] With this configuration, sealing of the battery pack by the outer frame (410) and venting of the gas by the first and second gas channels can be easily achieved.

[0134] The above isolation frame (420) is intended to isolate each battery assembly (e.g., cell stack unit (100)) accommodated between the partitions (210). For example, even if the upper pack housing (300) is coupled to the lower pack housing (200), the multiple battery assemblies are not completely sealed off from each other in a state where air circulation is possible. Between the upper pack housing (300) and the partition (210), a space is formed to accommodate the installation space for the mechanism installed on the inner side of the upper pack housing (300) or cables required for electrical connection. Additionally, a certain volume of spare space is provided so that gas generated from the battery cell (110) can be discharged. Because of this, each battery assembly is isolated to the left and right by the partition (210), but the venting gas can be circulated through the upper space of the battery assembly. Accordingly, if ignition occurs in a specific battery cell (110) and high-temperature venting gas or flames are generated, said gas or flames may propagate beyond the adjacent partition (210) to other neighboring battery assemblies. The isolation frame (420) is intended to delay or prevent this. The isolation frame (320) is installed extending parallel to the partition (210) on the inner side of the outer frame. Thus, when the gasket (400) is attached to the upper surface of the lower pack housing (200), the isolation frame is attached to the upper surface of the partition (210) and can completely isolate neighboring battery assemblies together with the partition (210). However, since a space is formed between the isolation frames, the gasket (400) alone cannot completely spatially seal the battery assemblies. For complete sealing, it is necessary to install the upper pack housing (300) on the gasket (400).

[0135] Referring to FIG. 12, battery assemblies (e.g., cell stack unit (100)) are isolated from each other within a lower pack housing (200) by a partition (210). Additionally, the outer frame (410) of a gasket (400) is attached to the upper surface of the side wall frame (231) of the lower pack housing (200), and the isolation frame (420) is attached to the upper surface of the partition (210), so that each battery assembly is securely isolated in the height direction. Furthermore, the upper pack housing (300) is attached to the lower pack housing (200) while covering the gasket (400), thereby sealing each battery assembly.

[0136] Since adjacent battery assemblies are blocked (sealed) by the partition wall (210), isolation frame (420), and upper pack housing (300), the propagation of high-temperature venting gas or flame between battery assemblies can be prevented. Thus, according to the present invention, sealing of the battery pack can be achieved by installing a gasket (400) that isolates the battery assemblies together with the partition wall (210) between the upper and lower pack housings (200).

[0137] Meanwhile, the gas inlet (321) of the upper pack housing (300) can be formed on the lower surface of the upper pack housing (300) located above each isolated battery assembly. That is, as shown in FIG. 12, if the gas inlet (321) is formed on the lower surface of the upper pack housing (300) located above each battery assembly, the gas generated from each battery assembly is discharged upward toward the gas inlet (321). However, as described above, since each battery assembly is blocked in the left and right directions by the partition wall (210) and the gasket (400), the gas cannot flow into the space where the neighboring battery assembly is accommodated. Therefore, even if ignition occurs in one battery assembly and gas is generated, it is possible to prevent the gas from spreading to the adjacent battery assembly. In addition, the gas can be quickly discharged upward from the battery assembly where ignition occurred. Each gas inlet (321) is rapidly discharged to the outside through the first gas channel (H1) of the upper pack housing (300) and the second gas channel (H2) of the side wall frame communicating therewith. The gas inlet (321) may be formed on the lower surface of the upper pack housing (300) facing the upper surface of the corresponding battery assembly so as to correspond to each battery assembly. That is, a dedicated gas inlet (321) may be formed for each battery assembly. However, it is not limited thereto; for example, if a plurality of rows of unit units (100) are arranged in the extension direction of the partition wall (210), a single gas inlet (321) serving the plurality of rows may be formed. In short, the present embodiment may form at least one gas inlet (321) per receiving space of battery assemblies (battery modules (10) or cell stack unit units (100)) isolated by the partition wall (210).

[0138] As described above, the present embodiment has the advantage of being able to more effectively prevent gas from propagating to adjacent battery assemblies while rapidly discharging high-temperature gas to the outside of the battery pack by providing a gasket (400) and first and second gas channels.

[0140] (Third embodiment)

[0141] FIG. 13 is a partially exploded perspective view of a battery pack of another embodiment of the present invention, FIG. 14 is an exploded view of the pack housing of the battery pack of FIG. 13, FIG. 15 is a schematic diagram showing the assembly process of a unit frame assembly which is a component of the battery pack of FIG. 13, and FIG. 16 is a cross-sectional view showing a gas venting path according to the battery pack of FIG. 13.

[0142] The battery pack (3000) of the present embodiment is different from the prior embodiment in the configuration of the lower pack housing (200'). In the present embodiment, the lower pack housing (200') includes a unit frame assembly (A) and a side wall frame (230) coupled along the perimeter of the unit frame assembly (A).

[0143] The present embodiment is characterized by having a plurality of unit frames (T) that support the bottom surface and one side surface of the battery assembly (e.g., cell stack unit unit (100)), and by sequentially combining the unit frames (T) like Lego blocks so that the bottom surface area of ​​the battery pack can be increased or decreased as needed. That is, the unit frame assembly (A) can perform the functions of the base plate (220) and the partition wall (210) of the first and second embodiments.

[0144] Referring to FIGS. 14 and 15, the unit frame (T) is provided with a partition wall (210') extending in the height direction and a base plate (220') extending along one side direction (either left or right direction) from the bottom of the partition wall (210'). The base plates of the unit frames (T) are sequentially joined in a row along one side direction to form a unit frame assembly (A). That is, the unit frame (T) is joined in a row along the side direction (left or right direction) by the bottom end (220b') of the partition wall (210') of the base plate (220') of one unit frame (T) being sequentially joined to the one-side extension end (220a') of the subsequent unit frame base plate, thereby forming a unit frame assembly (A). The base plate (220') supports the lower surface of each battery assembly. Thus, the joined base plates form a base plate (220) like a conventional battery pack. By increasing or decreasing the number of connections of the unit frames (T), the unit frame assembly (A) can become larger or smaller in the lateral direction. That is, the bottom surface area of ​​the battery pack formed by the base plates can be changed as needed.

[0145] In addition, the partition wall (210') of the unit frame (T) performs the same function as the partition wall (210) of the first and second embodiments. That is, as shown in FIG. 15, by sequentially connecting the unit frames (T) in a lateral direction, the partition walls (210') of adjacent unit frames (T) are positioned facing each other. Each battery assembly (100) can be placed in the space between these opposing partition walls (210'). Therefore, by sequentially connecting the unit frames (T) in a lateral direction, the area of ​​the floor where the battery assembly (100) is placed is increased, and the number of partition walls partitioning the battery assembly can also be naturally increased. However, the partition wall (210') of the unit frame (T) at the rear end of the unit frame assembly does not partition the adjacent battery assembly and can serve as a side frame on one side of the battery pack.

[0146] In this way, by connecting unit frames (T) laterally with varying numbers of connections, much like Lego blocks, the size of the battery pack can be adjusted to meet a wide variety of required specifications. Accordingly, the electrical capacity of the battery pack can also be freely adjusted to meet the required performance. Therefore, according to this embodiment, the design freedom of the battery pack can be significantly increased.

[0147] Referring to FIG. 13, each battery assembly in which battery cells are stacked has a certain width in the cell stacking direction (a direction parallel to the left-right direction) and is extended in the length direction (a direction parallel to the front-back direction) to have a certain length. Each of the battery assemblies is accommodated in the space between adjacent partitions (210') of the unit frame assembly (A). At this time, the lower surface of each battery assembly is supported by the base plate of each unit frame (T), and both sides of the battery assembly in the width direction are supported by the opposing partitions (210) of the adjacent unit frame (T).

[0148] Meanwhile, the unit frame (T) is extended to a certain length along the front-rear direction. That is, the bulkhead (210') and the base plate are extended along the front-rear direction. The front-rear length of the bulkhead (210) and the base plate is determined to sufficiently accommodate the front-rear length of the cell stack extension unit (10) (i.e., battery assembly). That is, the front-rear length of the unit frame (T) is determined according to the length of the battery cell (110) constituting the cell stack extension unit.

[0149] The above bulkhead (210') and base plate (220') can be manufactured by forming them as a single unit. Alternatively, the unit frame (T) can be manufactured by arranging two flat plates vertically so that one end of each plate is in contact and welding the ends of the contacting flat plates together.

[0150] The above unit frame (T) can be manufactured as a hollow frame by extruding a metal material such as aluminum to form an internal empty space. By configuring the unit frames (T) in a hollow form in this way, the weight of the battery pack can be reduced and energy efficiency increased. The hollow space formed in the unit frame (T) can also be used as a passage for cooling fluid to pass through or as a venting channel for venting gases generated within the battery pack.

[0151] The above unit frames (T) can be joined together by welding, for example, friction stir welding. In this case, a stepped portion can be formed at the lower end of the bulkhead (210) of the base plate of the unit frame (T) with a shape that matches the shape of the front end of the base plate (220') of the subsequent unit frame (T). That is, as shown in FIG. 15, a stepped portion is provided at the lower end (220b') of the bulkhead (210') of the base plate (or the lower end of the bulkhead (210) connected to the base plate end). The shape of this stepped portion is designed to interlock with the shape of the front end of the base plate of the subsequent unit frame. Therefore, by joining the laterally adjacent base plates so that they interlock at the stepped portion, the joint strength of the unit frames (T) can be increased. In addition, since the joint surface of the stepped portion and the base plate can support the load of the bulkhead (210') of the unit frame (T) and the battery assembly in the height direction, there is an advantage in that the load of the battery assembly can be appropriately distributed.

[0152] Referring again to FIG. 13, the battery assembly is arranged in two rows along the extension direction of the partition wall (210') between the battery assembly and the partition wall (210'). To accommodate the two rows of battery assemblies, the unit frame (T) is also extended in the front-rear direction.

[0153] That is, each unit frame (T) has two or more partitions (210') positioned in a row spaced apart at a predetermined interval along the front-rear direction, and a base portion (220') that extends in one direction from the bottom of each partition (210') and also extends long along the front-rear direction. The partitions (210') are formed in a row along the base plate (220') in the front-rear direction and can support battery assemblies in each row.

[0154] The battery assembly may be arranged in three or more rows in the front-rear direction, and the partition wall (210') of the unit frame (T) may also be provided in three or more rows in the front-rear direction in correspondence.

[0155] As illustrated in FIG. 14, when the unit frame (T) is assembled to form a unit frame assembly (A), one side of the unit frame arranged at the front, rear, and foremost of the unit frame assembly (A) is opened. A side wall frame (230) is joined along the perimeter of the unit frame assembly (A) to form a lower pack housing (200').

[0156] The above side wall frame (230) may be composed of a front frame (231) coupled to the front end of the unit frame assembly (A) in the front-rear direction, a rear frame (232) coupled to the rear end of the front-rear direction, and first and second side frames (233, 234) coupled to the left-right direction of the unit frame assembly (A).

[0157] The above front frame (231) may have a front cover portion extending in the height direction and a front plate portion protruding forward from the lower part of the front cover portion.

[0158] The rear frame (232) may also have a rear cover portion extending in the height direction and a rear plate portion protruding rearward from the lower part of the rear cover portion.

[0159] The height of the front cover and rear cover may be the same as the height of the partition wall (210) of the unit frame.

[0160] In addition to the unit frame mentioned above, the first and second side frames, the front frame (231), and the rear frame (232) can also be manufactured as hollow frames with internal spaces. By doing so, the weight of the battery pack can be further reduced.

[0161] In this embodiment as well, a gasket (400) similar to that in the first embodiment may be provided. The gasket (400) is coupled to the upper surface of the side wall frame (230) of the lower pack housing (200') and to the bulkhead (210') of the unit frame assembly (A). Specifically, the outer frame (410) of the gasket (400) is coupled to the upper surface of the front frame (231), the upper surface of the rear frame (232), and the upper surface of the first and second side frames (233, 234) that constitute the lower pack housing (200). Additionally, the isolation frame (420) of the gasket (400) is coupled to the bulkhead (210') of the unit frame assembly (A).

[0162] By combining the above gasket (400) and the lower pack housing (200), adjacent battery assemblies are completely isolated in the left and right directions with respect to the partition wall (210') and the isolation frame (420).

[0163] Afterwards, the battery assemblies can be individually sealed by joining the upper pack housing (300) to the open upper surface of the lower pack housing (200') with the gasket (400) interposed.

[0164] At this time, if a gas inlet (321) communicating with a first gas channel (H1) is formed on the lower surface of the upper pack housing (300) facing each isolated battery assembly, the gas generated in each unit (100) can be rapidly discharged upward while preventing gas propagation to neighboring battery assemblies. This gas is discharged to the outside through the first gas channel (H1) and the second gas channel (H2).

[0165] Accordingly, according to the present embodiment, the battery pack can be designed to be expandable by configuring the lower pack housing (200') using a unit frame. In addition, by attaching a gasket (400) to the unit frame assembly (A), the battery assemblies can be sealed to prevent high-temperature gas and flames from propagating to adjacent battery assemblies. Furthermore, high-temperature gas can be rapidly discharged to the outside through gas inlets (321) and gas channels communicating with each battery assembly.

[0166] Referring to FIG. 16, the width of the outer frame (410) is formed to be smaller than the width of the lower surface of the side wall frame of the upper pack housing (300), and a first venting hole (320a) is formed on the lower surface of the side wall frame that is not covered by the outer frame. Additionally, the upper surface of the outer frame is not made to cover the second venting hole (231a) formed on the upper surface of the rim of the lower pack housing (200'). Thus, the first and second venting holes (320a, 231a) of the upper pack housing (300) and the lower pack housing (200') are connected, allowing gas to be discharged to the outside through the side wall frame. In this case, since the width of the outer frame (410) is made smaller so that the space between the upper and lower pack housings (300, 200') is not completely blocked, there is no need to form a through passage (411) in the outer frame as in FIG. 12.

[0168] The foregoing description is merely an illustrative explanation of the technical concept of the present invention, and those skilled in the art to which the present invention pertains will be able to make various modifications and variations within the scope of the essential characteristics of the present invention. Accordingly, the drawings disclosed in this invention are intended to explain, not limit, the technical concept of the present invention, and the scope of the technical concept of the present invention is not limited by these drawings. The scope of protection of the present invention shall be interpreted by the claims below, and all technical concepts within an equivalent scope shall be interpreted as being included within the scope of rights of the present invention. Explanation of the symbols

[0170] 10: Battery module 100: Cell stack unit 110: Battery cell 120: Busbar Assembly 121: Busbar 122: Terminal Bus Bar 130: Cushioning pad 200,200': Lower pack housing 210: Bulkhead 220: Base plate 230; side wall frame 231: Front frame 231a: Second venting hole 232: Rear frame 232a: Second venting hole 233: 1st Side Frame 234: Second Side Frame V1, V2: Venting mechanism 250: Center Frame 210': Bulkhead 220': Base plate T: Unit frame A: Unit frame assembly 300: Upper pack housing 310: Top plate frame 320: Bottom plate frame 320a: First venting hole 321: Gas Inlet H1: 1st gas channel H2: Second gas channel 400: Gasket 410: Outer frame 411: Penetrating Passage 420: Isolation Frame 1000,2000,3000: Battery pack

Claims

Claim 1 A battery pack comprising: a plurality of battery assemblies; a lower pack housing having an open upper surface and accommodating the plurality of battery assemblies; and an upper pack housing coupled to the open upper surface of the lower pack housing, wherein the upper pack housing has a gas inlet into which gas generated within the battery pack is introduced and a first gas channel communicating with the gas inlet, and the lower pack housing has a side wall frame having a second gas channel communicating with the first gas channel and a gas outlet communicating with the second gas channel to discharge the gas to the outside of the battery pack, and wherein a rim portion of the upper pack housing is coupled to the side wall frame of the lower pack housing, a first venting hole communicating with the first gas channel is formed at the lower portion of the rim portion, and a second venting hole communicating with the first venting hole and also communicating with the second gas channel is formed at the upper portion of the side wall frame. Claim 2 delete Claim 3 In claim 1, the upper pack housing comprises a lower plate frame having a gas inlet formed therein and an upper plate frame coupled to the lower plate frame to form a first gas channel between it and the lower plate frame. Claim 4 A battery pack according to claim 1, wherein the upper pack housing is configured as a hollow structure having a first gas channel formed inside, and a plurality of gas inlets communicating with the first gas channel are formed on the lower surface. Claim 5 A battery pack according to claim 1, wherein the side wall frame is a hollow structure having a second gas channel formed inside, and the gas outlet is formed at least one along the outer wall of the side wall frame. Claim 6 In claim 1, the battery pack wherein the first gas channel and the second gas channel are oriented in different directions. Claim 7 A battery pack according to claim 1, wherein a venting mechanism is installed at the gas outlet of the side wall frame, the venting mechanism comprising a gas sealing member that deforms at a predetermined pressure and / or a predetermined temperature or higher to open the gas outlet to the outside. Claim 8 A battery pack according to claim 1, wherein the upper pack housing and the side wall frame are made of different materials, and the material of the upper pack housing has higher heat resistance than the material of the side wall frame. Claim 9 A battery pack according to claim 1, wherein a plurality of partitions are installed in the bottom portion of the lower pack housing, disposed between each battery assembly, and the side wall frame is coupled along the perimeter of the bottom portion. Claim 10 In claim 9, the bulkhead is a battery pack having a height equal to or greater than the height of the battery assembly. Claim 11 In claim 9, the distance between adjacent bulkheads is smaller than the width of each battery assembly of the battery pack. Claim 12 A battery pack according to claim 9, wherein the battery assembly is arranged in two or more rows along the extension direction of the partition between adjacent partitions, and two or more partitions are installed spaced apart at a predetermined interval in the arrangement direction of the battery assembly corresponding to the number of rows of the battery assembly, and further includes a center frame that extends perpendicularly to the arrangement direction of the battery assembly and is installed at a predetermined interval between the partitions. Claim 13 A battery pack further comprising, in claim 9, a gasket coupled to the upper surface of the side wall frame of the lower pack housing and the bulkhead to isolate each battery assembly accommodated in the lower pack housing together with the bulkhead. Claim 14 In Clause 13, the gas inlet is formed on the lower surface of the upper pack housing, each of which is located on the upper part of the isolated battery assembly. Claim 15 In claim 9, the lower pack housing comprises a plurality of unit frames each having a bulkhead and a base plate extending in one direction from the bottom of the bulkhead, wherein the unit frames are joined in a row along the lateral direction by successively joining the bottom end of the base plate of one unit frame to the end extending in one direction of a subsequent unit frame base plate; and a battery pack comprising a side wall frame joined along the perimeter of the unit frame assembly.

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