Battery module and battery pack including same

Abstract

A battery module according to the present invention includes a battery cell assembly in which two or more battery cells, each having leads formed on both longitudinal ends, are arranged in a row in the longitudinal direction to form a longitudinal unit cell, and the longitudinal unit cells are stacked in two or more rows in a thickness direction of the battery cell, and a module case in which the battery cell assembly is housed, wherein the module case is arranged perpendicular to the thickness direction of the battery cell, covers both side surfaces of the battery cell assembly, and has one side plate and an other side plate facing each other, wherein a coupling protrusion is formed on the one side plate, and a coupling recess into which the coupling protrusion can be fitted is formed on the other side plate.

Description

[Technical Field]

[0001] The present invention relates to a battery module.

[0002] More specifically, the present invention relates to a battery module that is configured to be expandable, has a structure that can prevent deformation during assembly of the battery module, and can discharge gas from within the module.

[0003] The present invention also relates to a battery module stack constructed of the battery modules and a battery pack including the battery module stack.

[0004] This application claims the benefit of priority based on Korean Patent Application No. 10-2021-0155901 dated November 12, 2021, and all contents disclosed in the documents of that Korean patent application are incorporated herein by reference. [Background technology]

[0005] In recent years, rechargeable secondary batteries have been widely used as energy sources for wireless mobile devices. Secondary batteries are also attracting attention as energy sources for electric vehicles and hybrid electric vehicles, which are being proposed as a solution to address air pollution caused by existing gasoline and diesel vehicles that use fossil fuels. Therefore, the types of applications using secondary batteries are becoming increasingly diverse due to the advantages of secondary batteries, and secondary batteries are expected to be applied to more fields and products in the future.

[0006] In addition, there is an increasing demand for battery modules that house a number of secondary batteries electrically connected in series or parallel as a power source for energy storage systems (ESS) and electric vehicles, and for battery packs that are configured with the battery modules.

[0007] Such a battery module or battery pack includes an external housing made of a metal material to protect a plurality of secondary batteries from external impact and to house and store them.

[0008] FIG. 1 is a perspective view and a side view showing a state in which expandable battery modules 1 proposed by the present applicant are stacked.

[0009] The applicant has constructed a battery cell assembly by arranging two or more battery cells in a row in the longitudinal direction to form a longitudinal unit cell, and stacking these longitudinal unit cells in two or more rows in the thickness direction of the battery cells. Furthermore, depending on the configuration of such a battery cell assembly, a module case is manufactured that extends long in the longitudinal direction and surrounds the battery cell assembly. The battery cell assembly is housed within the module case of FIG. 1. By constructing a battery cell assembly in the above-described configuration, the number of battery cells in the longitudinal direction and the number of rows of battery cells housed within the module case can be adjusted, thereby improving design flexibility. Furthermore, by stacking the battery cell assemblies in the longitudinal direction, for example, by stacking two to four battery cell assemblies in two to six rows in the thickness direction of the battery cells, rather than stacking several tens of battery cell assemblies as in the conventional method, the battery cell assembly can be constructed more compactly. Furthermore, by housing each battery cell assembly consisting of a small number of battery cells in a separate module case and stacking battery modules including such module cases in the lengthwise or thickness direction of the battery cells like Lego blocks, a battery pack can be freely configured taking into consideration the space in which the battery module or the battery pack is installed.In this way, the battery module proposed by the present applicant can be called an expandable battery module because it is possible to manufacture any number of different types of battery packs depending on the stacking (design) method.

[0010] However, when assembling and stacking battery modules 1 having such expandability, the following problems arise.

[0011] First, when battery modules 1 are stacked and housed in a battery pack for use, the battery cells in the battery module swell during charge and discharge under operating conditions, resulting in assembly deformation. When multiple battery cells in a battery cell assembly swell, the module case is also subjected to stress. This causes deformation of the assembled form of the expandable battery module, as shown in the lower drawing of FIG. 1. When the assembled form is deformed, electrical connection members such as sensing cables and sensing terminals that connect each battery module 1 also deform, which can cause poor contact during electrical transmission to the BMS or other external devices, and in severe cases, can even cause disconnection and result in a loss of electrical connection.

[0012] Second, if gas is generated within the battery module 1, there is a risk of fire due to overheating. Of course, in the case of a battery pack made up of the above-mentioned battery module 1, a relatively small number of battery cells are housed in each battery module case, which has the advantage that heat is not easily transmitted to adjacent battery modules 1. However, if there is a path through which gas cannot be discharged, stress due to swelling will be strong as shown in Figure 1, and the risk of fire cannot be completely eliminated.

[0013] Therefore, there is a need for the development of battery module-related technology that can prevent deformation of the assembled form due to swelling in an expandable battery module and a battery pack including the same, while efficiently discharging gas inside the module to prevent the spread of flames. [Prior art documents] [Patent documents]

[0014] [Patent Document 1] Korean Patent Registration No. 10-2259416 Summary of the Invention [Problem to be solved by the invention]

[0015] The present invention has been made to solve the above problems, and an object of the present invention is to provide an expandable battery module having a structure that can prevent deformation during assembly of an expandable battery module.

[0016] Another object of the present invention is to provide a battery module that can effectively discharge gas from within the battery module.

[0017] Another object of the present invention is to provide a battery module stack in which the battery modules are stacked, and a battery pack including the same. [Means for solving the problem]

[0018] To solve the above problems, a battery module according to the present invention includes a battery cell assembly in which two or more battery cells, each having leads formed on both longitudinal ends, are arranged in a row in the longitudinal direction to form a longitudinal unit cell, and the longitudinal unit cells are stacked in two or more rows in the thickness direction of the battery cells, and a module case in which the battery cell assembly is housed, wherein the module case is arranged perpendicular to the thickness direction of the battery cells, covers both sides of the battery cell assembly, and has one side plate and another side plate facing each other, and a coupling protrusion is formed on the one side plate, and a coupling recess shaped to fit the coupling protrusion is formed on the other side plate.

[0019] For example, the same number of the coupling protrusions and the same number of the coupling recesses may be formed at corresponding positions along the longitudinal direction of the one side plate and the other side plate.

[0020] Specifically, the coupling protrusions and coupling recesses may be formed at the front end, the middle portion and the rear end of the one side panel and the other side panel, respectively.

[0021] Specifically, the coupling protrusion and the coupling recess may be formed in pairs on the upper and lower portions of the one side plate and the other side plate, respectively.

[0022] As another example, a vent hole communicating with the outside may be formed in one of the coupling protrusion and the coupling recess.

[0023] In another aspect of the present invention, the battery module stack has a structure in which a plurality of the battery modules are stacked in a thickness direction of the battery cells, and the battery modules are coupled together by fitting a coupling protrusion formed on one side plate of one battery module into a coupling recess on the other side plate of an adjacent battery module.

[0024] As an example, the same number of coupling protrusions and coupling recesses are formed in parallel at corresponding positions along the longitudinal direction of one side plate and the other side plate of the battery module, and the coupling protrusion formed on one side plate of one battery module can be fitted into the coupling recess of the other side plate at the corresponding position of an adjacent battery module, thereby coupling the battery modules.

[0025] As a specific example, the coupling protrusions and coupling recesses may be formed at the front end, middle portion, and rear end portions of the one side panel and the other side panel, respectively, and the coupling protrusions formed on one side panel of one battery module may be fitted into the coupling recesses of the other side panel at a corresponding position of an adjacent battery module, thereby coupling the battery modules.

[0026] As a more specific example, the coupling protrusions and coupling recesses may be formed in pairs on the upper and lower parts of the one side panel and the other side panel, respectively, and the coupling protrusions formed on one side panel of one battery module may be fitted into the coupling recesses on the other side panel at a corresponding position of an adjacent battery module, thereby coupling the battery modules.

[0027] As another example, the coupling protrusion formed on one side panel of one battery module may be fitted into the coupling recess of the other side panel of the adjacent battery module with a predetermined gap therebetween.

[0028] As another example, a vent hole communicating with the outside may be formed in one of the coupling protrusion and the coupling recess, and when the coupling protrusion formed on one side panel of one battery module is coupled to the coupling recess on the other side panel of an adjacent battery module, the vent hole may be connected to the predetermined gap.

[0029] The present invention also provides a battery pack including the battery module stack. [Effects of the Invention]

[0030] According to the present invention, even when battery modules configured to be expandable are stacked and assembled, deformation due to swelling can be effectively prevented.

[0031] In addition, gas inside the battery module can be effectively discharged through the vent holes in the module case, improving safety. [Brief explanation of the drawings]

[0032] [Figure 1] 1A and 1B are perspective and side views showing a state in which expandable battery modules proposed by the present applicant are stacked. [Figure 2] FIG. 1 is an exploded perspective view of an expandable battery module proposed by the present applicant. [Figure 3] 3 is a plan view showing the coupling relationship of a battery cell assembly which is a component of the battery module of FIG. 2. FIG. [Figure 4] 1 is an external perspective view of a battery module according to an embodiment of the present invention; [Figure 5] FIG. 5 is a perspective view showing the end structure of the battery module of FIG. 4. [Figure 6] FIG. 5 is a perspective view showing the structure of an intermediate portion of the battery module of FIG. 4. [Figure 7] FIG. 5 is a front view showing a state in which the battery modules of FIG. 4 are coupled together. [Figure 8] FIG. 1 is a schematic diagram illustrating a battery module stack according to an embodiment of the present invention. [Figure 9] FIG. 10 is a schematic view showing a battery module stack according to another embodiment of the present invention. [Figure 10] FIG. 10 is a schematic view showing a module case of a battery module according to another embodiment of the present invention. [Figure 11] FIG. 10 is a side cross-sectional view of a main part of a battery module stack according to another embodiment of the present invention. [Figure 12] 1 is a schematic diagram of a battery pack including a battery module stack constructed of the battery module of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0033] The present invention will be described in detail below. Before that, the terms and words used in the specification and claims should not be interpreted as being limited to their ordinary or dictionary meanings, but should be interpreted as meanings and concepts that are consistent with the technical idea of the present invention, based on the principle that the inventor can appropriately define the concepts of the terms in order to best describe his own invention.

[0034] As used throughout the present specification, terms such as "comprise" and "have" are intended to specify the presence of features, numbers, steps, operations, components, parts, or combinations thereof stated in the specification, and should be understood as not precluding the presence or possible addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0035] Furthermore, when a layer, film, region, plate, or other portion is described as being "on" another portion, this includes not only the case where it is "directly on" the other portion, but also the case where there is another portion between them. Conversely, when a layer, film, region, plate, or other portion is described as being "under" the other portion, this includes not only the case where it is "directly under" the other portion, but also the case where there is another portion between them. Furthermore, in the specification of the present invention, being "located on" can include not only the case where it is located at the top, but also the case where it is located at the bottom.

[0036] A battery module according to the present invention includes a battery cell assembly in which two or more battery cells, each having leads formed on both longitudinal ends, are arranged in a row in the longitudinal direction to form a longitudinal unit cell, and the longitudinal unit cells are stacked in two or more rows in the thickness direction of the battery cells, and a module case in which the battery cell assembly is housed. The module case is arranged perpendicular to the thickness direction of the battery cells, covers both sides of the battery cell assembly, and has one side plate and another side plate facing each other, and a coupling protrusion is formed on the one side plate, and a coupling recess shaped to fit the coupling protrusion is formed on the other side plate.

[0037] [Battery module] FIG. 2 is an exploded perspective view of an expandable battery module proposed by the present applicant, FIG. 3 is a plan view showing the coupling relationship of battery cell assemblies that are components of the battery module of FIG. 2, and FIG. 4 is an external perspective view of a battery module according to one embodiment of the present invention.

[0038] The battery module 1000 of the present invention includes a battery cell assembly 100 and a module case 200.

[0039] In Figure 2, with a standard pouch-type battery cell 10 having leads 11 and 12 formed at both ends and extending long in the longitudinal direction as the reference, the X direction is the longitudinal direction of the battery cell 10 or module case 200, the Y direction is the thickness direction of the battery cell 10 or module case 200 (the stacking direction of the battery cells), and the Z direction is the up-down direction.

[0040] The battery cell 10 of the present invention is a battery cell in which electrode leads 11, 12 are formed at both longitudinal ends (so-called bidirectional battery cells (bidirectional pouch cells)). With this configuration, the positive electrode lead 11 and the negative electrode lead 12 are respectively formed and led out from both ends of a single battery cell 10, eliminating interference between the leads and increasing the area of the electrode leads, making it easier to connect the electrode leads 11, 12 to bus bars.

[0041] The battery cell assembly 100 of the present invention includes a longitudinal unit cell 110, which is a longitudinal battery cell formed by arranging two or more such bidirectional battery cells 10 in a row in the longitudinal direction. Specifically, a bundle of battery cells in which the electrode leads 11, 12 of longitudinally opposing battery cells 10 are electrically connected to each other is referred to as a longitudinal unit cell 110. In FIGS. 2 and 3, two battery cells 10 are connected longitudinally to form a longitudinal unit cell 110, but two or more battery cells can also be connected longitudinally. In principle, the number of battery cells 10 connected longitudinally is not limited as long as there is space in the battery pack in which the battery module case 200 or battery module 1000 is installed. However, due to practical limitations on the space available for a battery module 1000 or battery pack installed in an automobile, it is preferable to connect approximately two to four battery cells 10 longitudinally.

[0042] The battery cell assembly 100 included in the battery module 1000 of the present invention is formed by stacking the longitudinal unit cells 110 in two or more rows in the thickness direction (Y direction) of the battery cell 10. The number of rows in which the longitudinal unit cells 110 are stacked also depends on the allowable space of the battery module 1000 and the battery pack, the size of the battery cells 10, etc. Furthermore, the number of battery cells 10 in the longitudinal direction and the number of rows can be determined taking into account the required capacity of the required electrical device, etc. As such, the present invention can adjust the number of battery cells in the longitudinal direction and the number of rows of the battery cell assembly 100 housed in the module case 200, thereby improving design flexibility. Furthermore, design flexibility can be improved by stacking as many battery modules 1000 as necessary in the thickness direction of the battery cell.

[0043] The expandable battery module 1000 of the present invention, or the structure of the battery pack described below, has a small number of battery cell assemblies 100 housed separately in the battery module 1000, so even if a fire occurs in a battery cell 10 in one battery module 1000, the fire is unlikely to spread to other battery modules 1000.

[0044] As described above, the battery cell assembly 100 of the present invention is a configuration in which battery cell assemblies 100 consisting of a specific number of battery cells 10 are connected in the longitudinal direction and the thickness direction of the battery cells, and are housed in respective module cases 200.

[0045] The battery cell assembly 100 of the present invention shown in FIGS. 2 and 3 is configured with a total of eight battery cells 10 in a so-called 2P4S connection structure in which two battery cells 10 are connected in the longitudinal direction and the longitudinal unit cells 110 are stacked in four rows.

[0046] However, by varying the number of rows of longitudinal unit cells 110 connected in pairs in the longitudinal direction, battery cell assemblies 100 can also be constructed with an even number of rows, such as four-row stacks (2P4S), six-row stacks (3P4S), or eight-row stacks (4P4S). Also possible are structures in which three rather than two cells are connected in the longitudinal direction (1P6S, 2P6S, 3P6S, ...), four cells are connected (1P8S, 2P8S, 3P8S, ...), or more cells are connected. In short, an advantage of the present invention is that the stacking structure of the longitudinal unit cells 110 and battery cell assemblies 100 can be varied in a diverse and scalable manner according to the design requirements of the battery module 1000 and battery pack described above.

[0047] Referring to FIG. 3 , it can be seen that the longitudinal unit cells 110 are electrically connected to each other. For example, the leads 11, 12 of the longitudinal unit cells 110 in adjacent rows at both ends of the battery cell assembly 100 can be connected by bending and welding. The leads 11, 12 of battery cells facing each other in the longitudinal direction can also be connected by welding. However, the leads of the battery cells where the terminal bus bars are connected may not be connected. In the top two rows of longitudinal unit cells in FIG. 3 , the leads of adjacent unit cells in the thickness direction of the battery cells are connected, but the leads facing each other in the longitudinal direction of the battery cells are not connected. However, the electrical connection structure of the longitudinal unit cells or the battery cell assembly 100 is not limited to that shown in FIG. 3 above. Various modifications are possible, such as changing the series or parallel connection structure, the installation position of the terminal bus bars, and the number of rows of longitudinal unit cells. Furthermore, instead of directly connecting the leads of the battery cells, the battery cells can be electrically connected using inter-bus bars.

[0048] A heat insulating plate or an insulating sheet may be installed between the rows of the longitudinal unit cells 110. In one embodiment of the present invention, a venting plate 300 having a venting channel therein is installed between the rows of the longitudinal unit cells 110. The venting plate 300 also performs a venting function of discharging gas generated within the battery module 1000 to the outside, but since this is not the main point of the present invention, detailed description thereof will be omitted.

[0049] The present invention also includes a module case 200 in which the battery cell assembly 100 is housed.

[0050] That is, as shown in Fig. 2, the present invention includes a module case 200 that encases and houses the battery cell assembly 100. The module case 200 has a rectangular parallelepiped structure that is elongated in the longitudinal direction so as to house the battery cell assembly 100 specific to the present invention. In Fig. 2, the module case 200 is formed by combining a C-shaped wall 210 and an I-shaped wall 220, but is not limited thereto. For example, two C-shaped walls arranged left and right or above and below can be combined, or the upper, lower, left, and right cases can be separated and joined by welding, hooking, or fastening members.

[0051] The module case 200 of the present invention also includes a front end plate 230 and a rear end plate 240. The front end plate 230 and the rear end plate 240 are respectively coupled to the combined body of the C-shaped wall 210 and the I-shaped wall 220 to close the front and rear of the module.

[0052] The present invention is characterized in that a unique coupling structure is provided in the module case 200, which can prevent swelling during assembly of the battery module 1000.

[0053] 4 shows the assembled state of the module case 200 of FIG. 2, housing the battery cell assembly 100 and internal module components. The module case 200 has a front end plate 230 and a rear end plate 240 at the front and rear ends, respectively, and one side plate 221 and another side plate 211 that are arranged perpendicular to the thickness direction of the battery cell 10 and cover both sides of the battery cell assembly 100, facing each other. Of course, the module case 200 also has upper and lower plates that cover the top and bottom of the battery cell assembly 100, and these front and rear end plates, one side plate and another side plate, and upper and lower plates constitute the module case.

[0054] The battery module 1000 of the present invention includes longitudinal unit cells 110 and therefore has a module case 200 that is elongated in the longitudinal direction. Therefore, a battery module stack can be formed by stacking battery modules 1000 in the thickness direction of the battery cells, which is perpendicular to the longitudinal direction of the battery cells 10, and a battery pack can be fabricated by housing and assembling this battery module stack in a battery pack case. As described above, since the shape of the battery module stack changes due to swelling when the battery modules are stacked, the present invention provides a coupling portion in each individual battery module 1000 that can couple with an adjacent battery module 1000.

[0055] That is, one of the two side panels that enclose the battery cell assembly 100 has a coupling protrusion 222 formed on one side panel 221 (see FIG. 2), and the other of the two side panels has a coupling recess 212 into which the coupling protrusion 222 can be fitted (see FIG. 4). FIG. 4 illustrates a battery module (case) according to one embodiment of the present invention, with the coupling recess 212 formed on the right side panel (other side panel 211) of the module case 200. The coupling protrusion 222 is formed on the left side panel (one side panel 221), which is not visible in FIG. 4. FIG. 2 illustrates the coupling protrusion 222 on the left side panel. In FIG. 4, the right side panel is the other side panel, and the left side panel is the one side panel. However, because the distinction between one side panel and the other side panel is relative, it is also possible to form the coupling protrusion on the right side panel and the coupling recess on the left side panel, as opposed to FIG. 4.

[0056] The battery module 1000 of the present invention is designed to be coupled to a plurality of adjacent battery modules 1000 in a stacked manner, and one side panel 221 of one battery module 1000 is coupled to the other side panel 211 of another adjacent battery module 1000. Therefore, the coupling protrusion 222 and the coupling recess 212 must be formed in shapes that allow them to be fitted into each other and coupled.

[0057] For example, if the coupling protrusion 222 is formed in the shape of a simple rectangular parallelepiped, the coupling recess 212 must have a concave space having the volume of the rectangular parallelepiped space into which the rectangular parallelepiped space can be tightly inserted. Therefore, in this case, the volume of the concave space of the coupling recess 212 must be formed slightly smaller than the volume of the coupling protrusion 222.

[0058] Alternatively, the width of the entrance portion, which is the edge of the coupling recess 212, can be made smaller than the width of the coupling protrusion 222 so that the coupling recess 212 can be forcibly fitted at the entrance portion, but a predetermined space can be formed between the coupling protrusion 222 and the inside of the coupling recess 212. For this reason, a configuration in which a protrusion like a hooking protrusion is formed at the entrance portion of the coupling recess 212 and the coupling protrusion 222 rides over the hooking protrusion to be coupled to the coupling recess 212 is also included in the scope of the present invention. In addition, a hook portion corresponding to the hooking protrusion can be formed on the coupling protrusion 222.

[0059] In other words, the term "a coupling recess 212 having a shape into which the coupling protrusion 222 can be fitted" as used in the present invention includes not only a simple protrusion-concave shape but also a coupling recess 212 having a shape that can be fitted together by having a hooking protrusion or the like, or any shape or form of a coupling protrusion 222 corresponding thereto.

[0060] 4 to 6, the same number of coupling protrusions 222 and coupling recesses 212 may be formed side by side at corresponding positions along the longitudinal direction of module case 200, specifically along the longitudinal directions of one side panel 221 and the other side panel 211. By forming the coupling protrusions 222 and the coupling recesses 212 at corresponding coupling positions, the shape of battery module 1000 can be standardized during manufacture, and multiple battery modules can be easily assembled using the standardized battery modules 1000, just like Lego.

[0061] In order to reliably couple adjacent battery modules, it is preferable to form the coupling protrusions 222 and coupling recesses 212 at at least three locations of the battery module 1000, i.e., the front end, middle end, and rear end, as shown in FIG. 4, which is extended long in the longitudinal direction.

[0062] In addition, since both side panels 211, 221 have a certain width in the vertical direction, it is preferable to form pairs of coupling protrusions 222 and coupling recesses 212 on the upper and lower parts of one side panel 221 and the other side panel 211. From this perspective, the battery module 1000 of FIG. 4 has coupling recesses 212 at a total of six locations on the other side panel 211, and the one side panel 221 on the left side (not visible) also has coupling protrusions 222 at a total of six locations. However, when forming pairs in the vertical direction, it is not necessary to form one coupling part at each of the upper and lower parts, and multiple coupling parts can be formed at each of the upper and lower parts as needed.

[0063] FIG. 5 is a perspective view showing the end structure of the battery module 1000 of FIG.

[0064] 5, coupling recesses 212 are formed on the upper and lower parts of the other side panel 211 at the front end of the battery module 1000, and coupling protrusions 222 are formed on the upper and lower parts of the opposing one side panel 221. For reference, within the case at the front end of the battery module 1000, the leads 11, 12 of the battery cells 10 located at the front ends of two rows of longitudinal unit cells 110 on the left and right are bent toward each other and connected. While FIG. 5 shows the structure at the front end of the battery module 1000, the same structure may be applied to the rear end.

[0065] FIG. 6 is a perspective view showing the structure of the middle part of the battery module 1000 of FIG.

[0066] 6, coupling recesses 212 are formed on the upper and lower portions of the other side panel 211 in the middle portion of the battery module 1000, and coupling protrusions 222 are formed on the upper and lower portions of the opposing side panel 221. In this case, two coupling portions are provided on the upper and lower portions of each side panel, one on each side, to strengthen the coupling. For reference, leads 11 and 12 of battery cells 10 facing each other in the longitudinal direction may be coupled inside the case in the middle portion of the battery module 1000. As described above, a terminal bus bar (not shown) may also be coupled to this portion.

[0067] [Battery module stack] (First embodiment) FIG. 7 is a front view showing the battery modules of FIG. 4 in a coupled state.

[0068] 7 shows two identical battery modules 1000 connected to each other, one on the left and one on the right. The battery module 1000 incorporates a so-called 2P4S battery cell assembly 100. The electrode leads 11, 12 of the frontmost battery cells of the battery cell assembly 100 are bent and connected to form an electrical connection. A connecting protrusion 222 formed on one side panel 221 of another adjacent battery module 1000 is fitted into a connecting recess 212 formed on the other side panel 211 of the adjacent battery module 1000. This type of connection can prevent assembly deformation due to swelling, even when several battery modules are stacked and connected in the thickness direction of the battery cells.

[0069] FIG. 8 is a schematic diagram showing a battery module stack according to one embodiment of the present invention.

[0070] 8 shows an increased number of battery modules 1000 than in FIG. 7. As shown, like Lego blocks, each battery module 1000 is firmly coupled to the other through coupling of each coupling protrusion 222 and coupling recess 212 in the thickness direction of the battery cell.

[0071] 7 and 8 has a structure in which the coupling protrusions 222 of the battery modules 1000 are tightly fitted into the coupling recesses 212 without any gaps. When the coupling protrusions 222 are tightly fitted into the coupling recesses 212 when the battery modules are coupled, the rigidity of the battery module stack 1100 is increased, which has the advantage of further strengthening the deformation suppression force during swelling.

[0072] Meanwhile, as will be described later, the second and third embodiments have a structure in which the coupling protrusion 222 is coupled to the coupling recess 212 with a predetermined gap therebetween. In this case, the gap between the battery modules can serve as a gas exhaust passage, which has the advantage of providing excellent venting function for safety.

[0073] (Second embodiment) FIG. 9 is a schematic diagram showing a battery module stack 1200 according to another embodiment of the present invention.

[0074] The structure of the battery module itself in this embodiment is the same as that in the first embodiment.

[0075] In this embodiment, when the battery module stack 1200 is constructed, the battery modules are coupled together by fitting the coupling protrusion 222 formed on one side panel 221 of one battery module 1000 into the coupling recess 212 of the other side panel 211 of the adjacent battery module 1000 with a predetermined gap G therebetween. To this end, the shapes of the coupling recess 212 and the coupling protrusion 222 may be modified. As shown in FIG. 9 , the protruding length of the coupling protrusion 222 may be made smaller than the depth of the coupling recess 212, thereby forming a predetermined gap G between the coupling protrusion 222 and the coupling recess 212. Alternatively, although not shown, the width of the entrance of the coupling recess 212 may be narrowed or a hooking protrusion may be formed at the entrance so that the protruding surface of the coupling protrusion 222 does not come into contact with the bottom surface of the coupling recess 212 after the coupling protrusion 222 passes through the entrance of the coupling recess 212 and is coupled to the coupling recess 212.

[0076] 9, since the coupling protrusion 222 and the coupling recess 212 are coupled together, deformation of the assembled configuration due to swelling can be suppressed. In particular, in this embodiment, a gap G is formed between the coupling recess 212 and the coupling protrusion 222, and this gap G serves as a venting passage between the battery modules 1000. For example, when a venting hole is formed in the module case of the battery module 1000, gas within the module may be discharged to the outside through the venting hole. In this case, the gap G may serve as a venting channel through which the gas discharged from the venting hole flows. That is, in this embodiment, the predetermined gap G functions as a venting channel extending in the longitudinal direction of the battery module 1000. For example, when the battery module stack 1200 is housed in a battery pack case and a venting hole communicating with the outside is formed in the battery pack case, gas discharged from each battery module may be discharged to the outside through the venting channel (gap) and the venting hole of the battery pack case.

[0077] As shown in FIG. 9, a gap G can be formed between each battery module, and therefore the battery module stack 1200 of this embodiment has a configuration including a plurality of venting channels.

[0078] Therefore, according to this embodiment, the structure can vent gas within the battery module 1000, and can improve the safety of the battery module 1000, the battery module stack 1200, and the battery pack while suppressing deformation of the battery module 1000 during assembly.

[0079] (Third embodiment) FIG. 10 is a schematic diagram showing a module case 200 of a battery module 1000 according to another embodiment of the present invention.

[0080] The module case 200 of this embodiment is characterized in that a vent hole H is formed in a coupling recess 212 formed in the other side panel 211 of both side panels that encase the battery cell assembly 100 .

[0081] A pair of vent holes H are formed in the coupling recess 212, so that gas generated within the module can be discharged to the outside through the vent holes H of the coupling recess 212.

[0082] FIG. 11 is a cross-sectional side view of a main part of a battery module stack 1300 according to another embodiment of the present invention.

[0083] 11(a) shows an assembled stack of battery modules to which the module case 200 of FIG. 10 is applied. In FIG. 11(a), the coupling recesses 212 and coupling protrusions 222 of adjacent battery modules 1000 are fitted and coupled with a predetermined gap G therebetween, and a venting hole H communicating with the predetermined gap G is formed in the coupling recesses 212 of each battery module 1000. Therefore, gas generated in each battery module 1000 can be more effectively discharged to the outside of the battery module 1000 or the battery module stack 1300 through the venting hole H of the coupling recesses 212 and the predetermined gap G (venting channel). That is, this embodiment goes beyond the structure in which the predetermined gap G is formed in the second embodiment and further improves the venting function of the battery module stack 1300 by forming a venting hole H directly connected to the predetermined gap G in the battery module 1000.

[0084] Such a venting hole H can be formed not only in the coupling recess 212 but also in the coupling protrusion 222. In (b) of Figure 11, a venting hole H' is formed on the coupling protrusion 222 side rather than the coupling recess 212, and the venting hole H' and a predetermined gap G are connected to each other.

[0085] In this way, this embodiment can utilize the connection space between the battery modules 1000 to more effectively discharge gas within the battery modules 1000, thereby further improving the safety of the battery modules 1000, the battery module stack 1300, and the battery pack.

[0086] However, the venting holes H, H' need to be formed only in one of the coupling protrusions 222 and the coupling recesses 212. If venting holes were formed in both the coupling protrusions 222 and the coupling recesses 212, adjacent battery modules would be in communication with each other via the venting holes and the gap G therebetween. In this case, if gas or a fire occurs in one battery module 1000, there is a risk that it will spread to the adjacent battery module 1000. That is, for the safety of the battery module stack 1300, it is preferable to form the venting holes only in one of the coupling protrusions 222 and the coupling recesses 212, thereby isolating adjacent battery modules from communicating with each other.

[0087] FIG. 12 is a schematic diagram of a battery pack 2000 including a battery module stack 1100 constructed from the battery modules 1000 of the present invention.

[0088] As described above, the battery module 1000 of the present invention includes a battery cell assembly 100 in which a predetermined number of battery cells 10 are stacked in the thickness direction of the battery cells as longitudinal unit cells 110, and a corresponding module case 200 that extends longitudinally. Therefore, like Lego blocks, the battery modules 1000 can be easily connected in the lengthwise or thicknesswise directions. As shown in FIG. 12, a plurality of expandable battery modules 1000 can be stacked in the lengthwise and / or thickness directions of the battery cells 10 within a single battery pack case 2100 to form battery module stacks 1100, 1200, and 1300. In addition to the configuration shown in FIG. 12, the stacking direction (shape) of the expandable battery modules 1000 can be changed to match the shape of the applicable battery pack case 2100. From this perspective, the expandable battery module 1000 of the present invention offers a high degree of design flexibility. In particular, as described above, the battery modules or battery module stacks 1200, 1300 of the second and third embodiments have a predetermined gap G (venting channel) between the battery modules 100, or have a venting hole H communicating with this gap. Therefore, for example, if a venting passage communicating with the venting hole H and the venting channel is formed in the battery pack case 2100, gas inside the battery pack 2000 can also be easily removed.

[0089] The drawings disclosed in the present invention are for the purpose of explanation, not for the purpose of limiting the technical idea of the present invention, and the scope of the technical idea of the present invention is not limited by such drawings. The scope of protection of the present invention should be interpreted by the claims, and all technical ideas within the equivalent range should be interpreted as being included in the scope of the present invention.

[0090] Although terms indicating directions such as up, down, left, right, front, and back are used in this specification, these terms are used for convenience of explanation, and it is obvious that they may change depending on the position of the object in question, the position of the observer, etc. [Explanation of symbols]

[0091] 10: Battery cell 11, 12: Electrode leads 100: Battery cell assembly 110: Longitudinal unit cell 200: Module case 210: C-shaped wall 220: I-shaped wall 211: Other side plate 212: Coupling recess 221:One side plate 222:Joining protrusion H, H': Venting holes G: Gap 230: Front end plate 240: Rear end plate 300: Venting plate 1000: Battery module 1100, 1200, 1300: Battery module stack 2100: Battery pack case 2000: Battery pack

Claims

1. a battery cell assembly in which two or more battery cells, each having a lead formed on both ends in the longitudinal direction, are arranged in a row in the longitudinal direction to form a longitudinal unit cell, and the longitudinal unit cells are stacked in two or more rows in the thickness direction of the battery cell; a module case in which the battery cell assembly is housed, the module case is arranged perpendicular to a thickness direction of the battery cells, covers both sides of the battery cell assembly, and includes one side plate and an opposite side plate facing each other; A coupling protrusion is formed on the one side panel, The other side panel is formed with a coupling recess having a shape into which the coupling protrusion can be fitted, A vent hole that communicates the inside and the outside of the module case is formed in one of the coupling protrusion and the coupling recess.

2. A battery module as described in claim 1, wherein in at least one of the longitudinal unit cells stacked in the thickness direction, the electrode leads of the battery cells opposing each other in the longitudinal direction are directly connected.

3. The battery module of claim 1 , wherein the same number of the coupling protrusions and the same number of the coupling recesses are formed at corresponding positions along the longitudinal direction of the one side panel and the other side panel.

4. The battery module according to claim 2 , wherein the coupling protrusions and the coupling recesses are formed at front, middle and rear ends of the one side panel and the other side panel, respectively.

5. The battery module according to claim 2 , wherein the coupling protrusions and the coupling recesses are formed in pairs on the upper and lower parts of the one side panel and the other side panel, respectively.

6. The battery module according to claim 1 is configured such that a plurality of the battery cells are stacked in the thickness direction of the battery cells, a connecting protrusion formed on one side panel of one battery module being fitted into the connecting recess of the other side panel of an adjacent battery module, thereby connecting the battery modules together;

7. the coupling protrusions and the coupling recesses are formed in the same number at corresponding positions along the longitudinal direction of the one side panel and the other side panel, 7. The battery module stack of claim 6, wherein the coupling protrusion formed on the one side panel of one battery module is fitted into the coupling recess of the other side panel at a corresponding position of an adjacent battery module, thereby coupling the battery modules together.

8. the coupling protrusion and the coupling recess are formed at the front end, the middle portion and the rear end of the one side panel and the other side panel, respectively; 7. The battery module stack of claim 6, wherein the coupling protrusion formed on the one side panel of one battery module is fitted into the coupling recess of the other side panel at a corresponding position of an adjacent battery module, thereby coupling the battery modules together.

9. The coupling protrusion and the coupling recess are formed in pairs on the upper and lower parts of the one side panel and the other side panel, respectively; 7. The battery module stack of claim 6, wherein the coupling protrusion formed on the one side panel of one battery module is fitted into the coupling recess of the other side panel at a corresponding position of an adjacent battery module, thereby coupling the battery modules together.

10. 7. The battery module stack of claim 6, wherein the coupling protrusion formed on the one side panel of the one battery module is fitted into the coupling recess of the other side panel of the adjacent battery module with a predetermined gap therebetween.

11. A battery module stack as described in Claim 10, wherein when the connecting protrusion formed on one side panel of one battery module is connected to the connecting recess on the other side panel of an adjacent battery module, the venting hole is connected to the specified gap.

12. A battery pack comprising the battery module stack according to any one of claims 6 to 11.

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