Battery module and battery pack including same

Abstract

A battery module according to one embodiment of the present invention includes a battery cell stack in which a plurality of battery cells are stacked; a module frame that houses the battery cell stack and has one and other open sides facing each other; and end plates that cover the one and other sides of the module frame, respectively. The module frame includes first bonding surfaces formed on edges that define the one and other sides, and the end plate includes second bonding surfaces that bond with the first bonding surfaces. A first rib is formed on one of the end plate and the module frame, protruding from the center of the first bonding surface and positioned inward from where the first and second bonding surfaces are joined, and a second rib is formed on one side of the first rib in the protruding direction. The other of the end plate and the module frame is formed with recesses that are recessed to correspond to the first and second ribs.

Description

[Technical Field]

[0001] [CROSS-REFERENCE TO RELATED APPLICATIONS] This application claims the benefit of priority based on Korean Patent Application No. 10-2023-0109681, filed on August 22, 2023, and all contents disclosed in the documents of this Korean patent application are incorporated herein by reference.

[0002] The present invention relates to a battery module and a battery pack including the same, and more particularly to a battery module with improved safety and productivity and a battery pack including the same. [Background technology]

[0003] In modern society, the use of portable devices such as mobile phones, laptops, video cameras, and digital cameras has become commonplace, and the development of technologies related to these mobile devices is accelerating. Furthermore, rechargeable secondary batteries are a solution to air pollution caused by existing gasoline-powered vehicles that use fossil fuels, and are used as power sources for electric vehicles (EVs), hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (P-HEVs), etc., which has led to an increasing need for the development of secondary batteries.

[0004] Currently available secondary batteries on the market include nickel-cadmium batteries, nickel-metal hydride batteries, nickel-zinc batteries, and lithium secondary batteries. Of these, lithium secondary batteries are attracting attention due to their advantages over nickel-based secondary batteries, such as almost no memory effect, freedom in charging and discharging, an extremely low self-discharge rate, and high energy density.

[0005] Such lithium secondary batteries mainly use lithium-based oxides and carbon materials as the positive and negative electrode active materials, respectively, and include an electrode assembly in which a positive electrode plate and a negative electrode plate, each coated with the positive and negative electrode active materials, are disposed with a separator between them, and a battery case that seals and houses the electrode assembly together with an electrolyte.

[0006] Generally, lithium secondary batteries can be classified into can-type secondary batteries, in which an electrode assembly is housed in a metal can, and pouch-type secondary 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.

[0007] While secondary batteries used in small devices typically have two to three battery cells, secondary batteries used in medium- to large-sized devices such as automobiles typically use battery modules, in which multiple battery cells are electrically connected. These battery modules improve capacity and output by connecting multiple battery cells in series or parallel to form a stack of battery cells. One or more battery modules may be installed with various control and protection systems, such as a battery management system (BMS), a battery disconnect unit (BDU), and a cooling system, to form a battery pack.

[0008] Since it is desirable to manufacture medium- to large-sized battery modules with as small a size and weight as possible, prismatic batteries and pouch-shaped batteries, which can be stacked with a high degree of integration and have a low weight-to-capacity ratio, are mainly used as battery cells for medium- to large-sized battery modules.

[0009] Meanwhile, the battery module may include a module frame and end plates that house a battery cell stack made up of a plurality of battery cells in an internal space to protect the plurality of battery cells from external impact, heat, or vibration.

[0010] Generally, to join the module frame and end plate, the module frame and end plate are placed facing each other and then welded together. During this process, weld spatter can damage internal components, including the battery cells. Therefore, there is a need for a technology that can solve this problem. Summary of the Invention [Problem to be solved by the invention]

[0011] An object of the present invention is to provide a battery module that can protect internal components when the module frame and end plates are welded together, and a battery pack including the battery module.

[0012] However, the problems to be solved by the embodiments of the present invention are not limited to the above-mentioned problems, and can be expanded to various problems within the scope of the technical ideas included in the present invention. [Means for solving the problem]

[0013] A battery module according to one embodiment of the present invention includes a battery cell stack in which a plurality of battery cells are stacked; a module frame that houses the battery cell stack and has one and other open sides facing each other; and end plates that cover the one and other sides of the module frame, respectively. The module frame includes first joint surfaces formed on edges that define the one and other sides, and the end plate includes second joint surfaces that are joined to the first joint surfaces. A first rib is formed on one of the end plate and the module frame, protruding from the center of the first joint surface and positioned inward from where the first and second joint surfaces are joined, and a second rib is formed on one side of the first rib in the protruding direction. The other of the end plate and the module frame is formed with recesses that are recessed to correspond to the first and second ribs.

[0014] The second rib may have a width narrower than that of the first rib and may protrude in a protruding direction of the first rib. A path may be formed on a surface of the first rib and the second rib facing the recess, where the first rib and the second rib are bent into multiple parts.

[0015] The recess may be recessed to correspond to a step structure formed at a boundary between the first rib and the second rib.

[0016] The first rib and the second rib can cover a portion where the first joint surface and the second joint surface are joined in the internal space of the module frame.

[0017] The first rib and the second rib may be connected along a direction in which the first joint surface and the second joint surface extend.

[0018] The battery module may further include at least one bus bar frame covering one or both sides of the battery cell stack.

[0019] The first rib and the second rib may be located between a portion where the first joint surface and the second joint surface are joined and the bus bar frame.

[0020] A bus bar connected to an electrode lead extending from the battery cell may be attached to the bus bar frame.

[0021] The first rib and the second rib may be formed on the end plate, the recess may be formed in the module frame, and the first rib may protrude from the end plate in a direction toward which the battery cell stack is located.

[0022] The first rib and the second rib may be formed on the module frame, the recess may be formed in the end plate, and the first rib may protrude from the module frame in a direction in which the end plate is located.

[0023] A battery pack according to an embodiment of the present invention includes the battery module. [Effects of the Invention]

[0024] According to an embodiment of the present invention, the end plates and module frames are provided with first and second ribs and corresponding recessed structures, which complicates the path into which welding spatter generated during welding of the module frame and end plates flows, thereby increasing the distance of the path, thereby preventing the welding spatter from damaging the internal components of the battery module.

[0025] The effects of the present invention are not limited to the effects described above, and other effects not mentioned will be clearly understood by those skilled in the art from the description of the claims. [Brief explanation of the drawings]

[0026] [Figure 1] 1 is a perspective view showing a battery module according to an embodiment of the present invention; [Figure 2] FIG. 2 is an exploded perspective view of the battery module of FIG. [Figure 3] 3 is a plan view showing one of the battery cells included in the battery module of FIG. 2. FIG. [Figure 4] 1 is a perspective view showing a module frame according to an embodiment of the present invention; [Figure 5] FIG. 5 is an exploded perspective view of the module frame of FIG. [Figure 6] 5A and 5B are respectively an enlarged perspective view and a plan view of the portion "B" in FIG. 5. FIG. [Figure 7] FIG. 2 is a perspective view showing an end plate and an insulating cover according to an embodiment of the present invention. [Figure 8] FIG. 8 is a perspective view showing a state in which the end plate and the insulating cover in FIG. 7 are joined together. [Figure 9] 9 is a perspective view of the end plate and the insulating cover of FIG. 8, viewed from a different angle. [Figure 10] 10 is an enlarged partial view of part "C" in FIG. 9. [Figure 11] FIG. 10 is a plan view of part "C" in FIG. 9 as seen from above. [Figure 12] FIG. 2 is a cross-sectional view showing a cross section taken along the line AA' in FIG. [Figure 13] FIG. 10 is a cross-sectional view of a battery module according to a comparative example of the present invention. [Figure 14] FIG. 4 is a cross-sectional view of a battery module according to another embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0027] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will now be described in detail with reference to the accompanying drawings, in which: FIG. 1 is a block diagram of a semiconductor device according to an embodiment of the present invention;

[0028] In order to clearly describe the present invention, parts not necessary for the description will be omitted and the same reference numerals will be used throughout the specification to refer to the same or similar components.

[0029] Furthermore, the size and thickness of each component shown in the drawings are arbitrarily shown for the convenience of explanation, and the present invention is not necessarily limited to those shown. In the drawings, the thicknesses of some layers and regions are exaggerated to clearly show them. In the drawings, the thicknesses of some layers and regions are exaggerated for the convenience of explanation.

[0030] Furthermore, when a layer, film, region, plate, or other part is said to be "on" or "above" another part, this does not only mean that it is "directly above" that part, but also includes cases where there are other parts between them. Conversely, when a part is said to be "directly above" another part, it means that there are no other parts between them. Furthermore, being "on" or "above" a reference part means being located above or below the reference part, and does not necessarily mean being located "above" or "above" the direction opposite to gravity.

[0031] Furthermore, throughout the specification, when a part is said to "comprise" a certain element, this does not mean that it may further include other elements, unless otherwise specified.

[0032] Also, throughout the specification, "on a plane" means a view of the subject part from above, and "on a cross section" means a view of the subject part cut vertically from the side.

[0033] Fig. 1 is a perspective view showing a battery module according to an embodiment of the present invention, Fig. 2 is an exploded perspective view of the battery module of Fig. 1, and Fig. 3 is a plan view showing one of the battery cells included in the battery module of Fig. 2.

[0034] 1 to 3, a battery module 100 according to an embodiment of the present invention includes a battery cell stack 120 in which a plurality of battery cells 110 are stacked; a module frame 200 that houses the battery cell stack 120 and has one and other open sides facing each other; and end plates 300 that cover the one and other sides of the module frame 200, respectively.

[0035] That is, the battery cell stack 120 may be housed in the internal space formed by the module frame 200 and the end plate 300. Also, if the module frame 200 is considered to have a hexahedral structure, one side of the module frame 200 that faces the electrode leads 111 of the battery cells 110 and the other side may be open.

[0036] When a plurality of battery cells 110 according to this embodiment are assembled, there is no particular limitation on the type of the battery cells. That is, the battery cells 110 according to this embodiment may be pouch-type battery cells, prismatic battery cells, or cylindrical battery cells. Hereinafter, as an example, the battery cells 110 according to this embodiment will be described as pouch-type battery cells.

[0037] A battery cell 110 according to an embodiment of the present invention may be a pouch-type battery in which an electrode assembly having electrode leads 111 protruding in one or both directions is housed in a pouch case 114. The battery cell 110 may be in the form of a rectangular sheet. The battery cell 110 may be formed by housing an electrode assembly in a pouch case 114 made of a laminate sheet including a resin layer and a metal layer, and then bonding the outer periphery of the pouch case 114. As an example, the battery cell 110 may have a structure in which two electrode leads 111 face each other and protrude from one end 114a and the other end 114b of the cell body 113, respectively. As another example, the electrode leads 111 of the battery cell 110 may all protrude in one direction. One of the electrode leads 111 is a positive electrode lead, and the other is a negative electrode lead.

[0038] The battery cell 110 may be manufactured by bonding both ends 114a, 114b of the pouch case 114 and one side 114c connecting them together while an electrode assembly (not shown) is housed in the pouch case 114. That is, the battery cell 110 according to one embodiment of the present invention may have a total of three sealing portions 114s, which are sealed by a method such as fusion, and the remaining side may be formed as a folding portion 115. That is, in the battery cell 110 according to this embodiment, the electrode assembly is housed inside the pouch case 114, and the pouch case 114 has a sealing portion 114s formed by sealing the outer periphery of the portion where the electrode assembly is housed. FIG. 3 only shows that sealing portions 114s are formed at both ends 114a and 114b of the pouch case 114, and does not show a sealing portion on the upper edge facing the folding portion 115, i.e., one side 114c, but the sealing portion on one side 114c is folded to one side after sealing is completed to utilize space.

[0039] The laminate sheet pouch case 114 can include an inner resin layer for sealing, a metal layer to prevent penetration of substances, and an outermost outer resin layer.

[0040] Based on the electrode assembly inside the pouch case 114, the inner resin layer may be located on the innermost side, the outer resin layer may be located on the outermost side, and the metal layer may be located between the inner and outer resin layers.

[0041] The outer resin layer may have excellent tensile strength and weather resistance relative to its thickness and electrical insulation properties to protect the electrode assembly from the outside. Such an outer resin layer may include polyethylene terephthalate (PET) resin or nylon resin. The metal layer may prevent air, moisture, etc. from entering the pouch-type secondary battery. Such a metal layer may include aluminum (Al). The inner resin layer may be heat-sealed by applying heat and / or pressure with the electrode assembly inside. Such an inner resin layer may include cast polypropylene (CPP) or polypropylene (PP).

[0042] The pouch case 114 may be divided into two sections, and at least one of the two sections may have a recessed storage section in which an electrode assembly can be placed. The inner resin layers of the two sections of the pouch case 114 may be joined together along the outer periphery of the storage section to form a sealing section 114s. The pouch case 114 may be sealed in this manner to manufacture the battery cell 110, which is a pouch-type battery.

[0043] The battery cell 110 is made up of multiple cells, and the multiple battery cells 110 can be stacked so as to be electrically connected to each other to form a battery cell stack 120. In particular, as shown in FIG. 2, the multiple battery cells 110 can be stacked in a direction parallel to the y-axis in an upright state with one surface of each cell body 113 (see FIG. 3) facing each other. This allows the electrode leads 111 to protrude in a direction perpendicular to the direction in which the battery cells 110 are stacked. That is, in the battery cell 110, one electrode lead 111 can protrude in the x-axis direction, and the other electrode lead 111 can protrude in the -x-axis direction.

[0044] Fig. 4 is a perspective view showing a module frame according to one embodiment of the present invention. Fig. 5 is an exploded perspective view of the module frame of Fig. 4. Fig. 6(a) and Fig. 6(b) are a perspective view and a plan view, respectively, showing an enlarged view of part "B" of Fig. 5. That is, Fig. 6(a) is a perspective view showing part "B" of Fig. 5 enlarged as is, and Fig. 6(b) is a plan view of part "B" of Fig. 5 viewed along the -z axis direction on the xy plane.

[0045] 2 and 4 to 6, the module frame 200 may be a structure that is open on one side and on the other side opposite the one side. More specifically, the module frame 200 may be open on both sides of the battery cell stack 120 where the electrode leads 111 protrude.

[0046] The module frame 200 according to one embodiment of the present invention may include a U-shaped frame 210 that covers the bottom and both side surfaces of the battery cell stack 120, and an upper cover 220 that covers the open top of the U-shaped frame 210. The U-shaped frame 210 may include a bottom 211 and two side surfaces 212 that extend upward from opposite sides of the bottom 211. The U-shaped frame 210 and the upper cover 220 may be joined to each other at their corresponding edges. More specifically, the two side surfaces 212 of the U-shaped frame 210 may be joined to opposite sides of the upper cover 220, respectively.

[0047] In another embodiment of the present invention, the module frame may be a mono-frame in which the top, bottom and both sides are integrated.

[0048] The module frame 200 according to this embodiment includes first bonding surfaces 200S formed on edges 200E that respectively define the one and other open surfaces. The first bonding surfaces 200S of the module frame 200 correspond to portions of the end plate 300 that are bonded to second bonding surfaces 300S, which will be described later. The first bonding surfaces 200S may be formed on all four edges 200E of the one open surface of the module frame 200. Although not shown in the drawings, the first bonding surfaces 200S may also be formed on all four edges of the other open surface of the module frame 200.

[0049] Meanwhile, the structure of the first and second ribs or recesses that may be formed on the module frame 200 will be described later.

[0050] Fig. 7 is a perspective view showing an end plate and an insulating cover according to an embodiment of the present invention, Fig. 8 is a perspective view showing the end plate and insulating cover of Fig. 7 in a combined state, and Fig. 9 is a perspective view of the end plate and insulating cover of Fig. 8 viewed from a different angle.

[0051] 2 and 7 to 9, end plates 300 according to an embodiment of the present invention cover the open one and other sides of a module frame 200. The module frame 200 and end plates 300 may include a metal material having a predetermined strength, and can protect the battery cell stack 120 housed within their internal space from external shocks and vibrations. In addition, an insulating cover 600 may be interposed between the battery cell stack 120 and the end plate 300 to prevent the end plate 300 from coming into contact with electrode leads or bus bars, which could cause a short circuit or other risk. The insulating cover 600 preferably includes an electrically insulating material.

[0052] Fig. 10 is an enlarged partial view of part "C" in Fig. 9. Fig. 11 is a plan view of part "C" in Fig. 9 seen from above.

[0053] 2 and 9 to 11, the end plate 300 includes a second joint surface 300S that is joined to the first joint surface 200S of the module frame 200 (see FIG. 6).

[0054] When the end plate 300 covers the open one and other sides of the module frame 200, the second joint surface 300S of the end plate 300 faces and corresponds to the first joint surface 200S of the module frame.

[0055] The first joining surface 200S of the module frame 200 and the second joining surface 300S of the end plate 300 are joined in abutting contact with each other. More specifically, welding may be performed in a state in which the first joining surface 200S of the module frame 200 and the second joining surface 300S of the end plate 300 are in abutting contact with each other, thereby joining the end plate 300 to the module frame 200.

[0056] FIG. 12 is a cross-sectional view showing a cross section taken along the line AA' in FIG.

[0057] 2, 5, 6, and 9 to 12, in this embodiment, a first rib 300R1 is formed on one of the end plate 300 and the module frame 200, protruding from the inside of the portion where the first and second bonding surfaces 200S and 300S are bonded. A second rib 300R2 is formed on one surface of the first rib 300R1 in the direction in which the first rib 300R1 protrudes. A recess 200D is formed on the other of the end plate 300 and the module frame 200, having a recessed shape corresponding to the first rib 300R1 and the second rib 300R2.

[0058] That is, in one embodiment of the present invention, the first rib 300R1 and the second rib 300R2 may be formed on the end plate 300, and the recess 200D may be formed on the module frame 200. In another embodiment of the present invention, the first rib and the second rib may be formed on the module frame, and the recess may be formed on the end plate.

[0059] On the other hand, the fact that the first rib 300R1 is located inside the portion where the first bonding surface 200S and the second bonding surface 300S are bonded means that, based on the internal space of the module frame 200 in which the battery cell stack 120 is housed, the first rib 300R1 is located closer to the battery cell stack 120 than the portion where the first bonding surface 200S and the second bonding surface 300S are bonded.

[0060] Hereinafter, as one embodiment of the present invention, an embodiment in which a first rib 300R1 and a second rib 300R2 are formed on the end plate 300, and a recess 200D is formed on the module frame 200 will be described.

[0061] In this embodiment, the first rib 300R1 may protrude from the end plate 300 in the direction in which the battery cell stack 120 is located. For example, the first rib 300R1 formed on the end plate 300 located in the x-axis direction of the battery cell stack 120 may protrude in the negative x-axis direction, and the first rib 300R1 formed on the end plate 300 located in the negative x-axis direction of the battery cell stack 120 may protrude in the x-axis direction. Meanwhile, as described above, the second rib 300R2 protrudes from one surface of the first rib 300R1 in a direction aligned with the protruding direction of the first rib 300R1.

[0062] As described above, during the process of welding the first joining surface 200S of the module frame 200 and the second joining surface 300S of the end plate together, welding flames may fly in all directions, resulting in welding spatter (SP), which may damage the battery cells 110 and other electrical components inside the battery module 100. Furthermore, if a laser beam is applied to the area where the first joining surface 200S and the second joining surface 300S are in contact during welding W, the laser beam may pass through the module frame 200 and the end plate 300 and damage the battery cells 110 and other internal components. However, the first rib 300R1 and the second rib 300R2 according to this embodiment can block the welding spatter SP and the transmitted laser beam from affecting the battery cells 110 and other internal components.

[0063] In particular, the first rib 300R1 and the second rib 300R2 may cover the portion where the first and second bonding surfaces 200S and 300S are bonded in the internal space of the module frame 200. The first rib 300R1 and the second rib 300R2 may be connected along the extending direction of the first and second bonding surfaces 200S and 300S. Here, the extending direction of the first and second bonding surfaces 200S and 300S is the same as the direction in which the edges 200E (see FIG. 4) constituting the open one and other surfaces of the module frame 200 are connected.

[0064] In addition, the first rib 300R1 and the second rib 300R2 according to one embodiment of the present invention may be formed to cover the entire area of ​​the bonded portion between the first and second bonding surfaces 200S and 300S, while the first rib 300R1 and the second rib 300R2 according to another embodiment of the present invention may be formed to cover only a portion of the bonded portion between the first and second bonding surfaces 200S and 300S.

[0065] Furthermore, it is preferable that the module frame 200 and the end plate 300 are fixed to each other in predetermined positions when the welding W is performed. In this embodiment, when the end plate 300 is joined to the module frame 200, the first rib 300R1 and the second rib 300R2 are inserted into the inner space of the module frame 200, so that the end plate 300 can be joined in the correct position without shifting. In other words, the first rib 300R1 and the second rib 300R2 serve to improve the ease of temporary assembly between the module frame 200 and the end plate 300.

[0066] The end plate 300 may be fixed in place by the first rib 300R1 and the second rib 300R2 while the welding W is being performed. To effectively prevent the end plate 300 from coming off or to fix the end plate 300, the first rib 300R1 and the second rib 300R2 need to be positioned adjacent to the first bonding surface 200S and the second bonding surface 300S.

[0067] Furthermore, the first rib 300R1 and the second rib 300R2 can prevent distortion at the welded portion due to the generated heat, and even if some distortion occurs, the distortion or protrusion at the welded portion can be prevented from affecting the battery cell stack or other internal components.

[0068] Fig. 13 is a cross-sectional view of a battery module according to a comparative example of the present invention. In particular, Fig. 13 can correspond to a cross section of the same part as Fig. 12 in the battery module according to the comparative example of the present invention.

[0069] 13, a rib 30R is formed on an end plate 30 according to a comparative example of the present invention. Specifically, welding W is performed between the first joining surface 20S of the module frame 20 and the second joining surface 30S of the end plate 30, and the rib 30R of the end plate 30 is located inside the portion where the first joining surface 20S of the module frame 20 and the second joining surface 30S of the end plate 30 are joined. In other words, the comparative example of FIG. 13 is the same as the embodiment of FIG. 12, except that the second rib 300R2 and the recess 200D are not provided.

[0070] Although the rib 30R according to this comparative example can initially block the welding spatter SP, much of the welding spatter SP can eventually flow into the interior of the module frame 20 along the gap between the rib 30R and the U-shaped frame 21 portion of the module frame 20, potentially ultimately damaging the battery cells.

[0071] 12, in this embodiment, a second rib 300R2 is added to one side of the first rib 300R1, and a recess 200D is provided to correspond to the first rib 300R1 and the second rib 300R2. The second rib 300R2 may have a narrower width than the first rib 300R1 and may protrude in the protruding direction of the first rib 300R1. The recess 200D may also be recessed to correspond to a step structure formed at the boundary between the first rib 300R1 and the second rib 300R2.

[0072] Unlike the rib 30R according to the comparative example, the present embodiment further includes a second rib 300R2 and a recess 200D, which complicates the path through which the welding spatter SP flows and increases the distance of the path. The first rib 300R1 and the second rib 300R2 may be bent in multiple directions on the surface facing the recess 200D.

[0073] In this embodiment, the path through which the welding spatter SP flows in is complicated and the distance of the inflow path is long, which is effective in blocking the welding spatter SP from flowing in. In particular, since the welding spatter SP tends to flow immediately before the target, when the path is multiply bent and complicated as described above, the amount of welding spatter SP flowing in can be significantly reduced.

[0074] Meanwhile, the first rib 300R1 and the second rib 300R2 may be integral with the end plate 300, and the end plate 300 provided with the first rib 300R1 and the second rib 300R2 may be manufactured by processing and molding. Since a pre-set rib-like structure is not joined, a separate joining process is not required. Furthermore, the U-shaped frame 210 and the upper cover 220 of the module frame 200 may be processed and molded to provide the recess 200D.

[0075] Referring again to FIGS. 1, 2 and 12, the battery module 100 according to this embodiment may include at least one bus bar frame 400 covering one or both sides of the battery cell stack 120.

[0076] In one embodiment, two bus bar frames 400 may be located on both sides of the battery cell stack 120, and in another embodiment, one bus bar frame 400 may be located on one side of the battery cell stack 120. The bus bar frame 400 may be located between the battery cell stack 120 and the insulating cover 600 and may include an electrically insulating material. A bus bar 500 connected to the electrode leads 111 extending from the battery cells 110 for electrical connection between the battery cells 110 may be attached to the bus bar frame 400. Specifically, the bus bar 500 may be attached to the surface of the bus bar frame 400 opposite to the surface facing the battery cell stack 120.

[0077] The bus bar 500 electrically connects the battery cells 110 inside the battery module 100 and preferably includes a metal material to enable electrical connection. The electrode leads 111 extending from the battery cells 110 may be bent into the bus bar 500 after passing through slits formed in the bus bar frame 400. For example, one electrode lead 111 may be bent into the bus bar 500 after passing through a slit in the bus bar frame 400 located on one side of the battery cell stack 120, and connected to the bus bar 500. The other electrode lead 111 may be bent into the bus bar 500 after passing through a slit in another bus bar frame 400 located on the other side of the battery cell stack 120, and connected to the other bus bar 500. There are no particular limitations on the method of connecting the electrode leads 111 to the bus bar; for example, welding may be used. By connecting the electrode leads 111 of the battery cells 110 to the bus bar in this manner, the battery cells 110 can be electrically connected to each other via the bus bar. In this manner, high voltage (HV) connections can be made within the battery module 100. In addition, a connection portion 700 may be further provided for electrical connection between the electrical components mounted on each of the bus bar frames 400 located on one side and the other side of the battery cell stack 120. The connection portion 700 may be a flexible printed circuit board (FPCB) or a flexible flat cable (FFC).

[0078] In this case, the first rib 300R1 and the second rib 300R2 may be positioned between the portion where the first bonding surface 200S and the second bonding surface 300S are bonded and the bus bar frame 400. The first rib 300R1 and the second rib 300R2 according to this embodiment may prevent the bus bar frame 400 from being damaged by welding spatter SP or a transmitted laser beam.

[0079] Hereinafter, a battery module according to another embodiment of the present invention will be described with reference to Fig. 14. However, for the sake of convenience, parts that overlap with the above description will be omitted.

[0080] 14 is a cross-sectional view of a battery module according to another embodiment of the present invention. In particular, FIG. 14 may correspond to a cross-section of the same portion as FIG. 12 in a battery module according to another embodiment of the present invention.

[0081] 14, a first joining surface 200S of a module frame 200 and a second joining surface 300S of an end plate 300 are joined together, and a first rib 200R1 and a second rib 200R2 may be formed on the module frame 200, and a recess 300D may be formed on the end plate 300. The first rib 200R1 formed on the module frame 200 may protrude from the module frame 200 in a direction toward which the end plate 300 is positioned. The second rib 200R2 may protrude from one surface of the first rib 200R1 in a direction aligned with the protruding direction of the first rib 200R1.

[0082] As described above, during the process of welding the first joining surface 200S of the module frame 200 and the second joining surface 300S of the end plate together, there is a possibility that welding flames may scatter in all directions, resulting in welding spatter (SP). The first rib 200R1 and the second rib 200R2 can block the welding spatter SP and the transmitted laser beam from affecting the battery cells 110 and other internal components.

[0083] In addition, the structure of second rib 200R2 and recess 300D makes the path that welding spatter SP takes complicated and increases the distance of the inflow path, which is effective in blocking welding spatter SP from flowing in. In particular, since welding spatter SP tends to be generated immediately before the target, when the path becomes multiple and complicated as described above, the amount of welding spatter SP that flows in can be significantly reduced.

[0084] The embodiment of FIG. 14 differs from the embodiment of FIG. 12 in that first rib 200R1 and second rib 200R2 are formed on module frame 200 rather than on the end plate, and recess 300D is formed on end plate 300 rather than on the module frame. However, the functions and effects of first rib 200R1, second rib 200R2, and recess 300D are the same between the embodiment of FIG. 14 and the embodiment of FIG. 12. That is, in the embodiment of FIG. 14, the inflow path of welding spatter SP becomes more complex, and the distance of that inflow path is also longer. Therefore, a detailed description of the functions and effects of the embodiment of FIG. 14 will be omitted to avoid repetition.

[0085] In this embodiment, terms indicating directions such as front, back, left, right, up, and down are used, but these terms are used for convenience of explanation and may change depending on the position of the target object, the position of the observer, etc.

[0086] One or more battery modules according to the present embodiment described above may be mounted together with various control and protection systems such as a Battery Management System (BMS), a Battery Disconnect Unit (BDU), and a cooling system to form a battery pack.

[0087] The battery module or battery pack may be applied to various devices, specifically, but not limited to, transportation means such as electric bicycles, electric cars, and hybrids, and ESS (Energy Storage Systems).

[0088] Although the preferred embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements made by those skilled in the art using the basic concept of the present invention defined in the claims below also fall within the scope of the present invention. [Explanation of symbols]

[0089] 100 battery modules 110 battery cells 120 Battery cell stack 200 Module Frame 200D recess 200R1 1st rib 200R2 2nd rib 300 End Plate 300D recess 300R1 1st rib 300R2 2nd rib

Claims

1. a battery cell stack in which a plurality of battery cells are stacked; a module frame that houses the battery cell stack and has two opposing open sides; End plates covering the one surface and the other surface of the module frame, respectively Including, the module frame includes first joining surfaces formed on edges that respectively define the one surface and the other surface, the end plate includes a second joining surface joined to the first joining surface, a first rib is formed on one of the end plate and the module frame, the first rib protruding inward from a portion where the first bonding surface and the second bonding surface are bonded, and a second rib is formed on one surface of the first rib along a protruding direction of the first rib; The battery module has recesses formed in the other of the end plate and the module frame, the recesses corresponding to the first ribs and the second ribs.

2. The battery module of claim 1 , wherein the second rib has a width narrower than that of the first rib and protrudes in a direction in which the first rib protrudes.

3. The battery module according to claim 1 , wherein the first rib and the second rib have a plurality of bent paths formed on surfaces facing the recess.

4. The battery module according to claim 1 , wherein the recessed portion is recessed to correspond to a step structure formed at a boundary between the first rib and the second rib.

5. The battery module according to claim 1 , wherein the first rib and the second rib cover a portion of the interior space of the module frame where the first bonding surface and the second bonding surface are bonded.

6. The battery module of claim 1 , wherein the first rib and the second rib are connected along a direction in which the first bonding surface and the second bonding surface extend.

7. The battery module of claim 1 , further comprising at least one bus bar frame covering one or both sides of the battery cell stack.

8. The battery module according to claim 7 , wherein the first rib and the second rib are located between the bus bar frame and a portion where the first bonding surface and the second bonding surface are bonded.

9. The battery module according to claim 7 , wherein a bus bar connected to an electrode lead extending from the battery cell is attached to the bus bar frame.

10. the first rib and the second rib are formed on the end plate; The recess is formed in the module frame, The battery module according to claim 1 , wherein the first rib protrudes from the end plate in a direction toward which the battery cell stack is located.

11. the first rib and the second rib are formed on the module frame; The recess is formed in the end plate, The battery module according to claim 1 , wherein the first rib protrudes from the module frame in a direction toward the end plate.

12. A battery pack comprising the battery module according to claim 1.

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