Battery module and battery pack including the same

Abstract

A battery module according to the present invention includes: a cell unit stack consisting of a plurality of cell units stacked in one direction; a bus bar frame assembly disposed inside the cell unit stack and electrically connecting pouch-type battery cells; and a module case accommodating the cell unit stack and the bus bar frame assembly, wherein the cell unit includes at least one pouch-type battery cell; and a cell cover that surrounds the pouch-type battery cell and the bus bar frame assembly and is configured to have an open bottom.

Description

[Technical Field]

[0001] The present invention relates to a battery module, and more particularly to a battery module having excellent safety against thermal events and a battery pack including the same.

[0002] This application claims priority based on Korean Patent Application No. 10-2022-0168019 filed on December 5, 2022, and Korean Patent Application No. 10-2023-0043170 filed on March 31, 2023, and the contents disclosed in the specifications and drawings of those applications are incorporated herein in their entirety. [Background technology]

[0003] With the rapid increase in technological development and demand for various mobile devices, electric vehicles, energy storage systems (ESS), etc., interest in and demand for secondary batteries as an energy source is rapidly increasing. While nickel-cadmium batteries and nickel-metal hydride batteries were widely used as secondary batteries in the past, lithium secondary batteries have recently come into widespread use due to their flexible charging and discharging capabilities, extremely low self-discharge rate, and high energy density, as they have almost no memory effect compared to nickel-based secondary batteries.

[0004] Such lithium secondary batteries primarily use lithium-based oxides and carbon materials as the positive and negative electrode active materials, respectively, and include an electrode assembly in which a separator is sandwiched between positive and negative electrode plates coated with the positive and negative electrode active materials, and an exterior material, such as a battery case, that encloses the electrode assembly together with an electrolyte solution.

[0005] Generally, secondary batteries are classified into can-type batteries in which an electrode assembly is housed in a metal can and pouch-type batteries in which an electrode assembly is housed in a pouch made of an aluminum laminate sheet, depending on the shape of the exterior material.

[0006] The lithium secondary batteries that are widely used these days have an operating voltage of approximately 2.5 V to 4.5 V per battery. Therefore, in the case of electric vehicles and power storage devices that require large capacity and high output, a battery module or battery pack is constructed by connecting multiple lithium secondary batteries in series and / or parallel, and this is used as an energy source. In particular, to satisfy the output and capacity required for electric vehicles, the battery module or battery pack contains a very large number of lithium secondary batteries.

[0007] On the other hand, it is also important to design battery modules and battery packs to be able to withstand thermal events.

[0008] Referring to FIG. 1, a conventional battery module (developed by the present applicant) is configured by stacking cell units, each of which has approximately two to three pouch-type battery cells housed in a cell cover 2, in one direction to form a cell unit group 1, and assembling a bus bar frame assembly 3 to the cell unit group 1. Here, the cell cover has a shape that covers three sides (top, left, and right sides) of the stacked two to three pouch-type battery cells, and the bus bar frame assembly may include a plurality of bus bars welded to electrode leads located at the front or rear of the cell unit, and a bus bar frame that supports the plurality of bus bars and covers the front / rear of the cell unit group. A frame cover may be further attached to the front of the bus bar frame.

[0009] One of the purposes of forming a cell unit by using a cell cover to house two to three pouch-type battery cells and stacking multiple cell units to form a cell unit group is to block the propagation of thermal runaway in the pouch-type battery cells when a thermal event occurs, and to achieve directional venting to guide and exhaust vent gas emitted from the trigger battery cell in a predictable direction.

[0010] However, assembly tolerances between the cell unit group and the bus bar frame assembly (or frame cover) can result in gaps, such as those indicated by "Gap" in Figure 1, which can allow vent gas, particles, and the like to escape. If vent gas, etc. escapes in an unexpected direction, directional venting, which directs the vent gas, etc. in the intended direction, cannot be achieved. Furthermore, this can cause thermal damage to other battery modules and combustion materials around the module, potentially resulting in greater damage. Therefore, a solution to the above-mentioned problems is needed. Summary of the Invention [Problem to be solved by the invention]

[0011] The present invention has been made to solve the above technical problems, and aims to provide a battery module with excellent directional venting performance that discharges high-temperature gases, etc. in an intended direction when a thermal event occurs.

[0012] Another object of the present invention is to provide a battery module that can increase the support force and rigidity of pouch-type battery cells and can effectively block the transmission of thermal energy between pouch-type battery cells when a thermal event occurs.

[0013] The technical problems that the present invention aims to solve are not limited to the problems described above, and other problems not mentioned will be clearly understood by those skilled in the art from the description of the invention described below. [Means for solving the problem]

[0014] A battery module according to one aspect of the present invention includes: a cell unit stack consisting of a plurality of cell units stacked in one direction; a bus bar frame assembly disposed inside the cell unit stack and electrically connecting pouch-type battery cells; and a module case accommodating the cell unit stack and the bus bar frame assembly, wherein the cell unit may include at least one pouch-type battery cell; and a cell cover that surrounds the pouch-type battery cell and the bus bar frame assembly and is configured to have an open bottom.

[0015] The cell cover may include an upper cover portion configured to cover the battery cells housed therein and upper portions of the bus bar frame assembly; a first side cover portion and a second side cover portion extending downward from left and right edges of the upper cover portion, respectively, and configured to cover the left and right sides of the battery cells; and a front cover portion and a rear cover portion extending downward from a front end and a rear end of the upper cover portion, respectively, and configured to cover at least a portion of the bus bar frame assembly.

[0016] The cell cover may be configured such that the bottom side of the battery cell is open.

[0017] The cell cover may be configured such that the first side cover portion and the second side cover portion each have a length that is shorter than a length of the upper cover portion.

[0018] The cell cover has a symmetrical structure between the first side cover portion and the second side cover portion, and the portion between one end of the first and second side cover portions and the front cover portion, and the portion between the other end of the first and second side cover portions and the rear cover portion may each include an open side cutout portion.

[0019] In the cell unit stack, at least one of the cell covers may have a terminal hole through which a terminal bus bar provided on the bus bar frame assembly can pass.

[0020] the bus bar frame assembly includes a metal rod-shaped bus bar and a plate-shaped bus bar frame that supports the bus bar, The busbar frame may have a fitting groove configured to fit at least one of the end portions of the first side cover portion and the second side cover portion to a predetermined depth in the stacked cell units.

[0021] The module case may include a gas vent hole provided in a bottom plate that supports the cell unit stack below the cell unit stack.

[0022] The gas vent hole may be provided in the bottom plate at a position corresponding to a cell terrace from which an electrode lead of the pouch-type battery cell protrudes.

[0023] According to another aspect of the present invention, a battery pack including the above-described battery module can be provided. [Effects of the Invention]

[0024] According to the present invention, it is possible to provide a battery module having excellent directional venting performance, which discharges high-temperature gases and the like in a desired direction when a thermal event occurs.

[0025] Furthermore, the present invention can provide a battery module that can increase the support force and rigidity of pouch-type battery cells and effectively block the transmission of thermal energy between pouch-type battery cells when a thermal event occurs. [Brief explanation of the drawings]

[0026] [Figure 1] 1 is a diagram showing a portion of a battery module according to the prior art; [Figure 2] 1 is a schematic perspective view of a battery module according to an embodiment of the present invention; [Figure 3] FIG. 3 is a schematic exploded perspective view of the battery module of FIG. 2. [Figure 4] 1 is a perspective view of a cell cover according to an embodiment of the present invention, showing the cell cover before the wing portions are folded. FIG. [Figure 5] FIG. 5 is a perspective view showing the cell cover after the wing portions in FIG. 4 have been folded. [Figure 6] 10A to 10C are diagrams illustrating an example of an assembly process for a cell unit assembly and a bus bar frame assembly according to one embodiment of the present invention. [Figure 7] 10A to 10C are diagrams illustrating an example of an assembly process for a cell unit assembly and a bus bar frame assembly according to one embodiment of the present invention. [Figure 8] 10A to 10C are diagrams illustrating an example of an assembly process for a cell unit assembly and a bus bar frame assembly according to one embodiment of the present invention. [Figure 9] 1 is a partial cross-sectional view of a battery module according to an embodiment of the present invention; [Figure 10] 4 is another partial cross-sectional view of a battery module according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0027] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Terms and words used in this specification and claims should not be construed as being limited to their ordinary or dictionary meanings, but should be construed as meanings and concepts corresponding to the technical ideas of the present invention, based on the principle that the inventor himself can appropriately define the concepts of terms in order to best describe the invention. Therefore, it should be understood that the embodiment described in this specification and the configuration shown in the drawings are merely the most preferred embodiment of the present invention and do not represent the entire technical ideas of the present invention, and that there may be various equivalent and modified embodiments that can be substituted for them at the time of this application.

[0028] In the drawings, the size of each component or specific parts of the component may be slightly exaggerated, omitted, or illustrated schematically for ease of explanation and clarity. Therefore, the size of each component does not fully reflect the actual size. If a detailed description of related well-known functions or configurations is deemed to be likely to unnecessarily obscure the gist of the present invention, such detailed description will be omitted.

[0029] FIG. 2 is a schematic perspective view of a battery module according to one embodiment of the present invention, FIG. 3 is a schematic exploded perspective view of the battery module of FIG. 2, FIG. 4 is a perspective view of a cell cover according to one embodiment of the present invention, showing the cell cover before the wing portions are folded, and FIG. 5 is a perspective view of the cell cover in FIG. 4 after the wing portions are folded.

[0030] Referring to these figures, a battery module according to an embodiment of the present invention includes a cell unit stack 100, a bus bar frame assembly 200, and a module case 300.

[0031] 3, the cell unit stack 100 includes a plurality of cell units 101 stacked in one direction. Here, the cell unit 101 includes at least one pouch-type battery cell 110 and a cell cover 120 that at least partially surrounds the pouch-type battery cell 110. In particular, as will be described in detail below, the cell cover 120 is configured to surround at least a portion of the bus bar frame assembly 200.

[0032] The pouch-type battery cell 110 includes an electrode lead 111, an electrode assembly, an electrolyte, and a pouch case that sealably accommodates the electrode assembly and the electrolyte. For example, the pouch case may be composed of two pouch sheets, at least one of which may have a recessed groove. The electrode assembly and the electrolyte are placed in the recessed groove, and the edges of the two pouch sheets are heat-sealed. In this pouch-type battery cell 110, the portion that accommodates the electrode assembly is referred to as the receiving portion 112, the periphery of the receiving portion 112 is referred to as the edge portion, and the portion of the edge portion that is sealed by heat-sealing the pouch sheets is referred to as the sealed portion.

[0033] The electrode lead 111 has one end connected to the electrode assembly inside the pouch case and the other end protruding outside the pouch case, and a portion between the one end and the other end can be fixed between two pouch sheets when they are heat-sealed. The portion of the electrode lead 111 exposed outside the pouch case can function as an electrode terminal of the pouch-type battery cell 110.

[0034] A pouch-type battery cell 110 in which an electrode assembly is packaged using two pouch sheets may have four sealing portions (a front edge portion from which the electrode leads 111 protrude, a rear edge portion, and the remaining two side edge portions (corresponding to the upper edge portion and lower edge portion when the battery cell 110 is arranged upright as in this embodiment)). Furthermore, a pouch-type battery cell 110 in which an electrode assembly is packaged by folding one pouch sheet may have three sealing portions (a front edge portion from which the electrode leads 111 protrude, a rear edge portion, and one side edge portion). Hereinafter, of these sealing portions, the front edge portion and right edge portion from which the electrode leads 111 protrude will be referred to as cell terraces 113.

[0035] One or more of the pouch-type battery cells 110 may be accommodated inside the cell cover 120. For example, the accommodation portion 112 may be erected, and approximately two to three pouch-type battery cells 110 stacked horizontally may be accommodated in the cell cover 120.

[0036] The cell cover 120 allows the pouch-type battery cells 110 to be stably erected and placed inside the module case 300, protects the pouch-type battery cells 110 which are vulnerable to external impact, and further, when some of the battery cells 110 included in the battery module experience thermal runaway, can play a role in blocking the transmission of thermal energy (flame, high-temperature gas, etc.) from the trigger battery cell 110 to the other battery cells 110.

[0037] The cell cover 120 may be made of a metal material, for example, stainless steel (SUS) material having high rigidity and a high melting point.

[0038] Specifically, referring to Figures 4 and 5, the cell cover 120 includes an upper cover portion 121, a first side cover portion 122, a second side cover portion 123, a front cover portion 124, and a rear cover portion 125, and the lower side may be formed in an open shape.

[0039] The upper cover part 121 is configured to cover the upper edge part of the battery cell 110 accommodated inside the cell cover 120. Furthermore, the upper cover part 121 extends further than the first and second side cover parts 122 and 123 and is configured to cover the upper part of the bus bar frame assembly 200 as well.

[0040] The first side cover part 122 extends downward from the left edge of the upper cover part 121 and is configured to cover the left side of the battery cell 110 housed inside the cell cover 120. The second side cover part 123 extends downward from the right edge of the upper cover part 121 and is configured to cover the right side of the battery cell 110 housed inside the cell cover 120.

[0041] When one battery cell 110 is accommodated in the cell cover 120, the left side of the battery cell 110 refers to the left side of the battery cell 110, and the right side of the battery cell 110 refers to the right side of the battery cell 110. When a cell stack in which two or more battery cells 110 are stacked is accommodated in the cell cover 120, the left side of the battery cell 110 refers to the left side of the cell stack, and the right side of the battery cell 110 refers to the right side of the cell stack.

[0042] The first side cover part 122 and the second side cover part 123 may each be configured to have a length shorter than that of the upper cover part 121. As shown in Fig. 5, the first side cover part 122 and the second side cover part 123 may each be formed to extend downward from both side edges of the upper cover part 121 excluding both end parts of the upper cover part 121.

[0043] The front cover part 124 extends downward from the front end (-Y direction) of the upper cover part 121 to cover at least a portion of the bus bar frame assembly 200. The rear cover part 125 extends downward from the rear end (+Y direction) of the upper cover part 121 to cover at least a portion of the bus bar frame assembly 200. That is, as shown in Fig. 3, the front cover part 124 is configured to cover the bus bar frame assembly 200 connected to the front electrode lead 111 of the pouch-type battery cell 110, and the rear cover part 125 is configured to cover the bus bar frame assembly 200 connected to the rear electrode lead 111 of the pouch-type battery cell 110.

[0044] For example, the cell cover 120 before housing the pouch-type battery cell 110 may be provided in a shape having wings as shown in Fig. 4. Here, the wings refer to a portion extending in the -Y direction from a position indicated by "F1" in Fig. 4 and a portion extending in the +Y direction from a position indicated by "F2." In the case of the cell cover 120 according to an embodiment of the present invention, the wings may be folded downward to form a front cover portion 124 or a rear cover portion 125 as shown in Fig. 5.

[0045] The first side cover portion 122 and the second side cover portion 123 have a symmetrical structure, and as described above, the length of each of them is configured to be shorter than the length of the upper cover portion 121. Therefore, when the wing portion is bent at a right angle to the upper cover portion 121, as shown in Fig. 5, side cutout portions O may be formed by opening the portions between one ends of the first and second side cover portions 122, 123 and the front cover portion 124, and the portions between the other ends of the first and second side cover portions 122, 123 and the rear cover portion 125.

[0046] Meanwhile, when constructing a battery module, although not shown, it is possible to apply a bus bar frame assembly of a size corresponding to one cell cover 120, or, as in the present embodiment, it is also possible to apply a bus bar frame assembly 200 of a size corresponding to a plurality of cell covers 120 stacked in one direction. That is, in either case, the configuration of the cell cover 120 including the side cutout portion O according to the present invention allows the bus bar frame assembly 200 to be surrounded and accommodated inside the cell cover 120.

[0047] Hereinafter, with reference to FIGS. 6 to 8, a brief description will be given of an embodiment in which one bus bar frame assembly 200 is assembled to stacked cell covers 120. FIG.

[0048] First, a cell unit 101 is prepared, in which two to three pouch-type battery cells 110 are housed in each cell cover 120. At this time, a cell cover 120 with wings is used, as shown in Fig. 4. Then, as shown in Fig. 6, the cell units 101 are stacked in one direction to form a pre-assembled cell unit stack 100.

[0049] Next, as shown in FIG. 7, bus bar frame assemblies 200 are attached to the front and rear sides of the pre-assembled cell unit stack 100, respectively.

[0050] 8, the wings of the cell cover 120 are bent together so that the bus bar frame assembly 200 is surrounded by the cell cover 120. In this manner, by assembling the bus bar frame assembly 200 and the cell unit 101, the bus bar frame assembly 200 can be disposed inside the cell unit stack 100.

[0051] Meanwhile, it should be noted that the scope of the present invention is not limited to the above-described assembly example. For example, the bus bar frame assembly 200 and the pouch-type battery cells 110 may be first assembled, and then the assembly may be performed by integrating the assembled bus bar frame assembly 200 and the pouch-type battery cells 110 into the stacked cell covers 120. That is, the assembly may be performed by stacking a plurality of cell covers 120 shown in FIG. 5 and then covering the pre-assembled bus bar frame assembly 200 and the pouch-type battery cells 110 with the stacked cell covers 120.

[0052] As described above, the battery module according to this embodiment includes the cell cover 120 having a structure capable of covering five sides, including the upper cover portion 121, the first side cover portion 122, the second side cover portion 123, the front cover portion 124, and the rear cover portion 125. As shown in FIG. 8, the cell cover 120 can cover not only the pouch-type battery cell 110 but also the bus bar frame assemblies 200 located in front and behind the pouch-type battery cell 110.

[0053] 6 again, the bus bar frame assembly 200 may include a bus bar frame 210 and a plurality of bus bars 220. The bus bar frame 210 may be provided in the form of a plate having a size that substantially corresponds to the overall width and height of the stacked cell covers 120, and may be provided so as to be connectable to both end portions of the first and second side cover parts 122 and 123 of the stacked cell covers 120.

[0054] The bus bar frame 210 may have lead slits 211 through which the electrode leads 111 of the pouch-type battery cells 110 can be drawn out in the +Y direction or the −Y direction. In addition, the bus bar frame 210 may be made of, for example, a material having excellent electrical insulation and fire resistance, and may be configured to allow the bus bar 220 to be attached to its outer surface. In particular, the inner surface of the bus bar frame 210 facing the pouch-type battery cells 110 may be coated with a fire-resistant material, a heat-resistant material, or a fire-resistant substance.

[0055] The busbar frame 210 may also include a fitting groove 212 configured to fit at least one of the end portions of the first side cover portion 122 and the second side cover portion 123 to a predetermined depth in the stacked cell units 101.

[0056] 6, a plurality of the fitting grooves 212 may be provided on the inner surface of the bus bar frame 210 along the stacking direction of the cell covers 120. The number of the fitting grooves 212 may be appropriately determined depending on the number of stacked cell covers 120.

[0057] 9, the fitting groove 212 may be configured to fit the end of the first side cover portion 122 of the cell cover 120 to a predetermined depth. In this case, the fitting groove 212 may be configured to fit the end of the first side cover portion 122 of one cell cover 120 and the end of the second side cover portion 123 of the other cell cover 120 in two stacked cell covers 120.

[0058] Therefore, the bus bar frame 210 can be fixedly joined to the stacked cell covers 120 without using a separate fastening member. In addition, the stacked cell covers 120 are also held together by the bus bar frame 210, so that no play (gap) occurs between the cell covers 120.

[0059] The bus bar 220 is a means for connecting the pouch-type battery cells 110 in series and / or parallel, and may be formed in a rod shape and made of a metal material such as copper, aluminum, nickel, etc. The electrode leads 111 of the pouch-type battery cells 110 pass through lead slits 211 of the bus bar frame 210 and are drawn out to the outside of the bus bar frame 210, and the drawn-out portions may be attached to the surface of the bus bar 220 by a method such as welding.

[0060] Two of the bus bars 220 may be used as electrode terminals of the battery module. Here, the bus bars 220 used as electrode terminals of the battery module are particularly referred to as terminal bus bars 221 and 222, and the terminal bus bars 221 and 222 include a positive terminal bus bar 221 and a negative terminal bus bar 222. The terminal bus bars 221 and 222 may be formed to have a longer length than the other bus bars 220, and one end thereof may be exposed to the outside of the module case 300.

[0061] 2, the battery module of this embodiment has terminal bus bars 221, 222 with one end exposed at the top of the module case 300. To this end, the module case 300 has a case terminal hole 311 in a top plate 310 as shown in FIG. 3, and the cell unit stack 100 has a terminal hole TH in the outermost cell cover 120 of the cell covers 120 as shown in FIG. 6, through which the terminal bus bars 221, 222 can pass.

[0062] The case terminal holes 311 and the terminal holes TH may be insulated and sealed by, for example, an insulating gasket (not shown). Depending on the structure or positions of the terminal bus bars 221, 222, the number and positions of the terminal holes TH and / or the case terminal holes 311 may differ from those in this embodiment. In other words, in this embodiment, a terminal hole TH is formed in each of the two outermost cell covers 120. Alternatively, terminal holes TH may be formed in cell covers 120 other than the outermost cell cover 120, or terminal holes TH may be formed only in a plurality of cell covers 120. Alternatively, the terminal holes TH may not be formed in the cell cover 120, and the terminal bus bars 221, 222 may be configured to detour toward the side cutouts O of the cell cover 120 and extend to the outside of the module case 300.

[0063] The module case 300 is configured to have an internal space capable of accommodating the cell unit stack 100 and the bus bar frame assembly 200. The module case 300 according to an embodiment of the present invention may include a top plate 310 covering an upper portion of the internal space, a bottom plate 320 covering a lower portion of the internal space, a pair of side plates 330 and 340 covering both sides of the internal space, and a pair of end covers 350 and 360 covering the front and rear of the internal space, respectively.

[0064] 3, the bottom plate 320 and the pair of side plates 330, 340 may be integrally formed. Such an integration of the bottom plate 320 and the pair of side plates 330, 340 is called a U-frame. With a module case 300 including such a U-frame, a battery module can be assembled by placing the cell unit stack 100 inside the U-frame, coupling a top plate 310 to the top of the U-frame, and then coupling end covers 350, 360.

[0065] Also, thermal resin TR may be pre-applied to the bottom plate 320. Since the lower portion of the cell cover 120 is open, the bottom plate 320 may face the lower edge portion of the battery cell 110. By applying thermal resin TR so that no empty space (air layer) is formed between the bottom plate 320 and the lower edge portion of the battery cell 110, the heat dissipation efficiency of the battery cell 110 can be maximized.

[0066] 3, the module case 300 has a circular gas vent hole 321 in the bottom plate 320. The module case 300 has a plurality of gas vent holes 321 in the bottom, i.e., the bottom plate 320. Therefore, in the battery module according to the present invention, when gas or flame is generated in a battery cell 110, the gas or flame can be vented directionally downward in the module case 300.

[0067] Meanwhile, the pouch-type battery cell 110 may generate gas due to a side reaction, for example, during charging and discharging. In particular, during overcharging or overdischarging, a large amount of gas can significantly increase the internal pressure, potentially causing the pouch case to expand, resulting in a swelling phenomenon. If the swelling becomes severe, the adhesive strength of the heat-sealed seal weakens, causing the seal to break and gas to escape. In this case, the cell terrace 113, where the electrode lead 111 is located and which is relatively less airtight than other parts and generates more heat, is likely to be damaged first. In consideration of these structural characteristics of the pouch-type battery cell 110, the battery module according to an embodiment of the present invention has the gas vent hole 321 provided at a position corresponding to the cell terrace 113 from which the electrode lead 111 of the pouch-type battery cell 110 protrudes, as shown in FIGS. 9 and 10 , in order to minimize the diffusion of gas, etc., emitted from the battery cell 110 within the module case 300 and allow the gas, etc., to escape to the outside of the module case 300 via the shortest path.

[0068] 9, each gas vent hole 321 is configured to be located between the first side cover part 122 and the second side cover part 123 of each cell cover 120. In this case, the ratio of the distance between the first side cover part 122 and the second side cover part 123, i.e., the width of the cell cover 120 to the diameter of the vent hole 321, can be determined preferably in the range of 1:0.5 to 1:0.7.

[0069] According to this configuration, gases and the like emitted from the battery cells 110 housed in a specific cell cover 120 can be discharged to the bottom of the module case 300 only through the vent holes 321 located at the bottom of the specific cell cover 120. That is, since the entire circumference of the vent holes 321 is closed, downward directional venting of gases can be more effectively guided. In addition, there is an effect of preventing gases and the like from moving and spreading to other cell covers 120 adjacent to the specific cell cover 120.

[0070] According to the configuration of the battery module 10 according to the present invention as described above, when a thermal event occurs in the battery cell 110, gas and the like can be more effectively guided to the gas vent hole 321 provided at the bottom of the module case 300. Therefore, the battery module according to the present invention can have improved directional venting performance compared to conventional battery modules.

[0071] In addition, according to the present invention, the support force and rigidity of the pouch-type battery cells 110 can be increased, and in the event of a thermal event, the transmission of thermal energy between the pouch-type battery cells 110 can be effectively blocked.

[0072] Meanwhile, a battery pack according to the present invention may include one or more battery modules, and is applicable to automobiles such as electric vehicles.

[0073] As described above, although the present invention has been described using limited embodiments and drawings, the present invention is not limited thereto, and it goes without saying that various modifications and variations can be made by a person having ordinary knowledge in the technical field to which the present invention pertains within the technical spirit of the present invention and the equivalent scope of the appended claims.

[0074] On the other hand, in the present invention, terms indicating directions such as up, down, left, right, front, and back are used, but these terms are used for the convenience of explanation, and it will be obvious to those skilled in the art that these terms may differ depending on the position of the object in question, the position of the observer, etc. [Explanation of symbols]

[0075] 1 Cell unit group 2 Cell Cover 3 Busbar frame assembly 10 Battery Module 100 cell unit stack 101 cell unit 110 battery cells 111 Electrode lead 112 Storage unit 113 Cell Terrace 120 Cell Cover 121 Upper cover part 122 first side cover part 123 Second side cover part 124 Front cover part 125 Rear cover 200 Busbar frame assembly 210 Busbar Frame 211 Lead Slit 212 Fitting groove 220 Busbar 221 Positive terminal bus bar 222 Negative terminal bus bar 300 Module Case 310 Top Plate 311 Case terminal hole 320 bottom plate 321 Gas vent hole 330, 340 side plate 350 end cover 360 End Cover

Claims

1. a cell unit stack consisting of a plurality of cell units stacked in one direction; a bus bar frame assembly disposed inside the cell unit stack and electrically connecting the pouch-type battery cells; a module case that houses the cell unit stack and the bus bar frame assembly; Including, The cell unit comprises: A battery module comprising: at least one pouch-type battery cell; and a cell cover configured to surround the pouch-type battery cell and the bus bar frame assembly and to have an open bottom.

2. The cell cover is an upper cover portion configured to cover an upper portion of the pouch-type battery cell and the bus bar frame assembly housed therein; a first side cover portion and a second side cover portion extending downward from a left edge and a right edge of the upper cover portion, respectively, and configured to cover the left and right sides of the pouch-type battery cell; a front cover portion and a rear cover portion extending downward from a front end and a rear end of the upper cover portion, respectively, and configured to cover at least a portion of the bus bar frame assembly; The battery module of claim 1 , comprising:

3. The battery module according to claim 2 , wherein the cell cover is configured so that a bottom side of the pouch-type battery cell is open.

4. The cell cover is The battery module according to claim 2 , wherein the first side cover portion and the second side cover portion are each configured to have a length shorter than a length of the upper cover portion.

5. The cell cover is the first side cover portion and the second side cover portion have a symmetrical configuration, 3. The battery module according to claim 2, wherein a portion between one end of each of the first and second side cover portions and the front cover portion, and a portion between the other end of each of the first and second side cover portions and the rear cover portion each include an open side cutout portion.

6. In the cell unit stack, The battery module according to claim 1 , wherein at least one of the cell covers includes a terminal hole through which a terminal bus bar provided on the bus bar frame assembly can pass.

7. the bus bar frame assembly includes a metal rod-shaped bus bar and a plate-shaped bus bar frame that supports the bus bar, 3. The battery module according to claim 2, wherein the bus bar frame includes a fitting groove configured to fit at least one of an end portion of the first side cover portion and an end portion of the second side cover portion to a predetermined depth in the stacked cell units.

8. The battery module according to claim 1 , wherein the module case comprises a gas vent hole provided in a bottom plate that supports the cell unit stack below the cell unit stack.

9. The gas vent hole is The battery module according to claim 8 , wherein the bottom plate is provided at a position corresponding to a position of a cell terrace from which an electrode lead of the pouch-type battery cell protrudes.

10. A battery pack comprising the battery module according to any one of claims 1 to 9.

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