Battery module and battery pack including same

Abstract

The battery module of the present invention includes a battery cell stack in which a plurality of battery cells each having an electrode lead are stacked, a bus bar frame assembly coupled to the electrode leads, and side frames disposed on both sides of the battery cell stack and coupled to the bus bar frame assembly, one of the bus bar frame assembly and the side frame having a coupling protrusion and the other having an insertion coupling part, the coupling protrusion being inserted into the insertion coupling part to couple the bus bar frame assembly to the side frame, and both upper and lower surfaces of the battery cell stack except for a surface where the side frame and the bus bar frame assembly are coupled are open.The present invention also provides a battery pack including the battery module.

Description

[Technical field]

[0001] The present invention relates to a battery module including a battery cell stack, the top and bottom surfaces of which are open.

[0002] The present invention also relates to a battery pack in which a partition wall for dividing an accommodating space of a battery module is removed from the battery pack to improve the utilization of the internal space of the battery pack.

[0003] This application claims the benefit of priority based on Korean Patent Application No. 10-2022-0120412 dated September 23, 2022, and all contents disclosed in the documents of said Korean patent application are incorporated herein by reference. [Background technology]

[0004] 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 have been presented as a solution to address air pollution caused by existing gasoline and diesel vehicles that use fossil fuels. Therefore, the types of applications that use 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.

[0005] In the case of secondary batteries used in small equipment, two or three battery cells are arranged, but in the case of secondary batteries used in medium to large devices such as automobiles, a battery module in which many battery cells are electrically connected is used. In such battery modules, many battery cells are connected to each other in series or parallel to form a battery cell stack, thereby improving capacity and output.

[0006] FIG. 1 is an exploded perspective view of a conventional battery module 10. As shown in FIG.

[0007] Referring to FIG. 1, a battery cell stack 11 is combined with a bus bar frame assembly 12 and housed in a battery module housing. The battery module housing is composed of end plates 13 and a module frame. The module frame may include a U-shaped frame in which a lower frame 14 and a side frame 15 are integrally formed, and an upper frame 16 combined with the U-shaped frame to cover the open upper portion of the U-shaped frame. Alternatively, the module frame may be a mono frame in which the lower frame 14, the side frame 15, and the upper frame 16 are integrally formed. The battery cell stack 11 and the bus bar frame assembly 12 can be stably housed in an internal space formed by the end plates 13 and the module frame.

[0008] However, when a battery pack is constructed using such a conventional battery module, there is a problem in that the weight of the entire battery pack increases due to the weight and volume of the battery module housing itself, and the energy density of the battery pack decreases because the battery module housing occupies a large space.

[0009] In order to solve the above problems, some of the battery module housing structures have been omitted to reduce the weight and volume of the battery module. For example, the lower frame, upper frame, and thick end plates have been omitted, and a battery module is constructed with only a battery cell stack, a bus bar frame assembly, and a side frame. However, there was a problem in that it was not easy to properly fix the remaining components when some of the module housing structures are omitted. As a result, handling during the assembly process was difficult, and it was not easy to fix it inside the battery pack. In addition, there was a problem in that the side frame was not firmly connected to the battery cell stack and the bus bar frame assembly, and was unable to sufficiently support them.

[0010] Therefore, there is a need to develop a technology that can firmly securely couple the battery module components together while reducing the weight of the battery modules.

[0011] Meanwhile, a battery pack may be formed by arranging a plurality of battery modules together with various control and protection systems, such as a battery disconnect unit (BDU), a battery management system (BMS), and a cooling system.

[0012] FIG. 2 is a simplified diagram illustrating a conventional battery module 10 installed in a conventional battery pack 20. As shown in FIG.

[0013] 2, a conventional battery pack 20 includes a base plate 21 on which the battery module 10 is installed, and a side plate 22 surrounding an edge of the base plate 21. A center frame 24 that crosses the center of the base plate 21 and a partition wall 23 that is disposed perpendicular to the center frame 24 and defines the battery module mounting area S are installed on the base plate 21. The partition wall 23 defines the battery module mounting area S.

[0014] The partition 23 supports the battery module 10 on both sides of the battery module 10 and reinforces the structural rigidity of the battery pack 20. However, the partition 23 complicates the internal structure and increases the number of parts required for assembly. This increases the manufacturing cost of the battery pack. In addition, the partition 23 increases the weight of the battery pack, and the space occupied by the partition is used to install battery cells or battery modules, reducing the space utilization rate of the battery pack.

[0015] Therefore, it is necessary to simplify the internal structure of the battery pack so that the lightweight battery module can be easily installed and the space of the battery pack can be efficiently utilized. Summary of the Invention [Problem to be solved by the invention]

[0016] The present invention has been devised to solve the above problems, and has an object to improve the structural stability of a lightweight battery module by stably connecting a bus bar frame assembly and a side frame.

[0017] Another object of the present invention is to improve space utilization rate of the battery pack by eliminating the partition wall of the conventional battery pack. [Means for solving the problem]

[0018] To solve the above problems, a battery module of the present invention includes a battery cell stack in which a plurality of battery cells, each having an electrode lead, are stacked, a bus bar frame assembly coupled to the electrode leads, and side frames disposed on both side surfaces of the battery cell stack and coupled to the bus bar frame assembly, one of the bus bar frame assembly and the side frame having a coupling protrusion and the other having an insertion coupling portion, the coupling protrusion being inserted into the insertion coupling portion to couple the bus bar frame assembly and both the top and bottom of the battery cell stack except for a surface where the side frame and the bus bar frame assembly are coupled are open.

[0019] As a specific example, the bus bar frame assembly may be coupled to a front surface and a rear surface of the battery cell stack, the bus bar frame assembly may have through slits into which the electrode leads are inserted, and the electrode leads of different polarities of the battery cells that have passed through the through slits may be bent toward and coupled with each other, thereby fixing the battery cell stack to the bus bar frame assembly.

[0020] As a more specific example, the side frame may extend in the longitudinal direction of the battery cell stack longer than the length of the battery cell stack so that the front and rear ends of the side frame protrude from the front and rear faces of the battery cell stack, respectively, and insert coupling portions or coupling protrusions provided on inner surfaces of the front and rear ends of the side frame may be coupled to corresponding coupling protrusions or insert coupling portions provided on both side faces of the bus bar frame assembly.

[0021] As one example, the bus bar frame assembly may include a bus bar frame to which a bus bar is attached, and an insulating cover coupled to the bus bar frame on a surface of the bus bar frame opposite to a surface facing the battery cell stack.

[0022] As a more specific example, the side frame extends in the longitudinal direction of the battery cell stack longer than the length of the battery cell stack so that the front and rear ends of the side frame protrude from the front and rear faces of the battery cell stack, respectively, and the coupling protrusion or insert coupling portion is provided on both side faces of one of the bus bar frame and the insulating cover, and the insert coupling portion or coupling protrusion provided on the inner faces of the front and rear ends of the side frame may be coupled to a corresponding coupling protrusion or insert coupling portion provided on the bus bar frame or the insulating cover.

[0023] As another example, the coupling protrusions or insert coupling portions may be provided on both side surfaces of the bus bar frame and the insulating cover, respectively, and the insert coupling portions or coupling protrusions of the side frames may be coupled to corresponding coupling protrusions or insert coupling portions provided on the bus bar frame and the insulating cover, respectively.

[0024] As an example, the cross-sectional shape of the coupling protrusion may be one of a circle, a square, and a cross.

[0025] As a specific example, the bus bar frame assembly may have a coupling protrusion, the side frame may have an insertion coupling portion, and the insertion coupling portion may be a coupling groove into which the coupling protrusion is inserted and force-fitted.

[0026] As another example, the coupling protrusion may further include a screw coupling member that passes through the coupling hole and protrudes outside the coupling hole, is screwed to an end of the coupling protrusion protruding outside the coupling hole, and presses against an outer surface of the side frame.

[0027] As another example, the side frame may include a first side frame coupled to one side of the battery cell stack and a second side frame coupled to the other side, and the first side frame and the second side frame may have through fastening holes extending in a height direction.

[0028] As a specific example, the side frame may be composed of a first side frame coupled to one side of the battery cell stack and a second side frame coupled to the other side, and the first side frame and the second side frame may have complementary structures that interlock with each other.

[0029] As a more specific example, the first side frame has a first step portion protruding from an upper portion of its outer surface, and the second side frame has a second step portion protruding from a lower portion of its outer surface and having a shape that engages with the first step portion, and adjacent battery modules can be fastened to each other by the first step portion of the first side frame and the second step portion of the second side frame of adjacent battery modules engaging and coupling with each other.

[0030] In another aspect of the present invention, a battery pack includes a plurality of the battery modules and a pack housing that accommodates the plurality of battery modules, wherein the side frame is fastened to a bottom plate of the pack housing such that the battery modules are fixed to the pack housing, and a thermally conductive resin layer may be disposed between an open lower surface of the battery module and the bottom plate.

[0031] As another example, a pack housing may be included that accommodates the plurality of battery modules, and a first side frame and a second side frame of adjacent battery modules may be engaged with each other to form a partition member that separates adjacent battery cell stacks, and the partition member may be fastened to a bottom plate of the pack housing, thereby fixing the battery modules to the pack housing, and a thermally conductive resin layer may be disposed between the open lower surface of the battery module and the bottom plate. Effect of the Invention

[0032] According to the present invention, the bus bar frame assembly can be firmly coupled to the side frame, so that the bus bar frame assembly can be stably supported by the side frame even if a part of the module frame is omitted.

[0033] In addition, the battery module of the present invention omits a part of a module frame surrounding a battery cell stack, thereby reducing the number of module components and the module load. Therefore, when such a battery module is installed in a battery pack, the space utilization rate inside the pack can be improved, and the energy density of the battery pack can be increased. [Brief description of the drawings]

[0034] [Figure 1] FIG. 1 is an exploded perspective view of a conventional battery module. [Diagram 2] FIG. 1 is a schematic diagram showing an installation relationship between a conventional battery module and a battery pack. [Diagram 3] 1 is an exploded perspective view of a battery module according to a first embodiment of the present invention; [Figure 4] FIG. [Diagram 5] 11 is a schematic diagram showing a process of joining a side frame and a bus bar frame assembly. FIG. [Figure 6]1 is a perspective view of a battery pack in which a battery module according to a first embodiment of the present invention is installed. FIG. [Figure 7] 3 is a schematic diagram showing a process of installing the battery module in a battery pack according to the first embodiment of the present invention; FIG. [Figure 8] 11 is a schematic diagram showing a process in which a side frame of a battery module is installed on the bottom of a battery pack; FIG. [Figure 9] FIG. 9 is a side cross-sectional view of FIG. 8. [Figure 10] FIG. 11 is an exploded perspective view of a battery module according to a second embodiment of the present invention. [Figure 11] 13 is a schematic view showing a process of coupling a bus bar frame assembly and a side frame in a battery module according to a third embodiment of the present invention. FIG. [Figure 12] FIG. 13 is an exploded perspective view of a battery module according to a fourth embodiment of the present invention. [Figure 13] 13 is a schematic view showing a coupling relationship of a side frame according to a battery module according to a fourth embodiment of the present invention. FIG. [Figure 14] 13 is a schematic diagram of a coupling process of two battery modules according to a fourth embodiment of the present invention; FIG. [Figure 15] FIG. 11 is a schematic perspective view showing a battery module according to a fourth embodiment of the present invention installed in a battery pack. [Figure 16] 13 is a schematic view showing a process in which a side frame of a battery module is installed on a bottom of a battery pack according to a fourth embodiment of the present invention. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0035] 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 concept of the term to best describe his own invention.

[0036] In this application, the terms "comprise" and "have" are intended to specify the presence of a feature, number, step, operation, component, part, or combination thereof described in the specification, and are understood to not preclude the presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof. In addition, when a part such as a layer, film, region, or plate is described as being "on" another part, this includes not only the case where it is "directly on" the other part, but also the case where there is another part in between. Conversely, when a part such as a layer, film, region, or plate is described as being "under" another part, this includes not only the case where it is "directly under" the other part, but also the case where there is another part in between. In addition, in this application, being "on" may include not only the case where it is located on the top, but also the case where it is located on the bottom.

[0037] The battery module of the present invention includes a battery cell stack in which a plurality of battery cells, each having an electrode lead, are stacked, a bus bar frame assembly coupled to the electrode leads, and side frames disposed on both side surfaces of the battery cell stack and coupled to the bus bar frame assembly, one of the bus bar frame assembly and the side frame having a coupling protrusion and the other having an insertion coupling portion, the bus bar frame assembly and the side frame are coupled together by inserting the coupling protrusion into the insertion coupling portion, and both the upper and lower surfaces of the battery cell stack except for the surface where the side frame and the bus bar frame assembly are coupled together are open.

[0038] The battery pack of the present invention includes a plurality of the battery modules and a pack housing that accommodates the plurality of battery modules, and the side frame is fastened to a bottom plate of the pack housing, thereby fixing the battery modules to the pack housing, and a thermally conductive resin layer may be disposed between an open lower surface of the battery module and the bottom plate.

[0039] The battery pack of the present invention includes a pack housing that accommodates the plurality of battery modules, and a first side frame and a second side frame of adjacent battery modules are engaged with each other to form a partition member that separates adjacent battery cell stacks, and the partition member is fastened to a bottom plate of the pack housing, thereby fixing the battery module to the pack housing, and a thermally conductive resin layer may be disposed between the open lower surface of the battery module and the bottom plate.

[0040] Hereinafter, specific embodiments of the present invention will be described with reference to the drawings.

[0041] (First embodiment) FIG. 3 is an exploded perspective view of the battery module according to the first embodiment of the present invention, FIG. 4 is a front view of a bus bar frame, and FIG. 5 is a schematic view showing a process of combining a side frame and a bus bar frame assembly.

[0042] 3, the longitudinal direction of the battery module 100 is indicated as an L direction, the W direction is the width direction of the battery module 100, and the H direction is the height direction.

[0043] As shown in FIG. 3, the battery module 100 includes a battery cell stack 110 in which a plurality of battery cells 111 each having an electrode lead 112 are stacked, a bus bar frame assembly 120 connected to the electrode lead 112, and a side frame 130 disposed on both side surfaces of the battery cell stack 110 and connected to the bus bar frame assembly 120. One of the bus bar frame assembly 120 and the side frame 130 has a coupling protrusion 122 and the other has an insertion coupling portion 131. The coupling protrusion 122 is inserted into the insertion coupling portion 131 to couple the bus bar frame assembly 120 and the side frame 130, and both the upper and lower surfaces of the battery cell stack 110 except for the surface where the side frame 130 and the bus bar frame assembly 120 are coupled are open.

[0044] In the illustrated example, a plurality of battery cells 111 are stacked in the width direction W of the battery module to form a battery cell stack 110. The battery cells 111 are stacked such that their sides are in contact with each other, and the sides of adjacent battery cells may be fixed to each other with double-sided tape. Alternatively, a number of stacked battery cells may be bound with a band to form one battery cell stack 110. Both double-sided tape and bands may be used to stack the battery cells. However, the method of stacking the battery cells is not limited to this, and other methods capable of suitably stacking the battery cells and maintaining the shape of the stack may also be applied.

[0045] Meanwhile, the individual battery cells 111 include electrode leads 112 protruding in the longitudinal direction L. That is, a plurality of electrode leads 112 may protrude from the front and rear surfaces of the battery cell stack 110. In this case, bus bar frame assemblies 120 coupled to the electrode leads 112 may be disposed on the front and rear surfaces of the battery cell stack 110.

[0046] The bus bar frame assembly 120 may include various bus bars (eg, inter bus bars, terminal bus bars) electrically connected to electrode leads, flexible circuit boards connected to the bus bars, connectors, and the like.

[0047] Referring to FIG. 3, the bus bar frame assembly 120 of the present embodiment includes a bus bar frame 121 including the bus bar, a flexible circuit board, a connector, and the like, and an insulating cover 123 coupled to the bus bar frame 121. The insulating cover 123 is for electrically insulating the battery module and is made of an insulating material. For example, the insulating cover 123 may be made of, but is not limited to, PC (polycarbonate), ABS (Acrylonitrile Butadiene Styrene), or a combination thereof. The bus bar frame assembly 120 includes an insulating cover 123 coupled to the bus bar frame 121 on a surface opposite to a surface facing the battery cell stack. In this case, the through slit may be provided in the bus bar frame 121. In the illustrated example, the insulating cover 123 and the bus bar frame 121 are configured separately, but the insulating cover 123 and the bus bar frame 121 may be manufactured as an integrated part as necessary to simplify the structure.

[0048] 4(a), terminal bus bars 124 may be attached to both ends of a bus bar frame 121. The battery module 100 may be electrically connected to an external electric device or another adjacent battery module via the terminal bus bars 124. The bus bar frame 121 may have a plurality of through slits 125 into which the electrode leads 112 of the battery cells 111 are inserted. The bus bar frame assembly 120 is coupled to the front and rear surfaces of the battery cell stack 110. The through slits 125 may be suitably provided in correspondence with the positions of the electrode leads 112.

[0049] 4(b), the electrode leads 112 of the battery cells having different polarities that have passed through the through slits 125 are bent toward each other and coupled to each other, thereby electrically connecting the individual battery cells 111 that constitute the battery cell stack 110. At this time, the electrode leads 112 located at the outermost shell among the electrode leads 112 that have passed through the through slits 125 may be bent toward the terminal bus bar 124 and coupled to the terminal bus bar 124.

[0050] The ends of the electrode leads of different polarities may be stacked so as to overlap each other and then joined by welding. When the electrode leads of adjacent battery cells are passed through the through slits of the busbar frame 121 and bent and joined in this manner, the busbar frame 121 is fitted between the body of the battery cell 111 and the electrode lead combination. In this way, the battery cell stack 110 and the busbar frame 121 may be fixed to each other. Thereafter, an insulating cover 123 is joined to the side of the busbar frame 121 opposite to the side from which the electrode leads protrude, thereby completing the assembly of the busbar frame assembly 120 and the battery cell stack 110.

[0051] Meanwhile, the electrode leads can also be electrically connected via an interbusbar. That is, an interbusbar can be installed at a position between electrode leads of different polarities, and the electrode leads of different polarities can be bent toward the interbusbar, and then each electrode lead can be welded to the interbusbar. However, in the present invention, since a part of the module frame of the battery module is omitted to simplify the structure, the electrode leads are directly connected without the interbusbar even when electrically connecting the electrode leads. This can further reduce the number of parts of the battery module and reduce manufacturing costs.

[0052] A side frame 130 is disposed on both sides of the battery cell stack 110. That is, in the present invention, the module frame (side frame 130) is disposed only on both sides of the battery cell stack 110, instead of surrounding all the top, bottom, left and right sides of the battery cell stack 110 as in the conventional module frame of FIG. 1. In this sense, the battery module 100 of the present invention can be said to be a module with a moduleless structure that does not have a part of the module case. Since such a battery module does not have a part that covers the upper and lower sides of the module frame, the module weight can be reduced. In addition, as described below, when the battery module is installed in a battery pack, the lower part of the module directly contacts the thermally conductive resin layer in the battery pack, so that the cooling path is simplified and the cooling efficiency is also increased. Thus, although the present invention uses the term battery module, it can be said that the battery cells are actually installed directly in the battery pack in a form in which the battery cells are exposed in the battery pack. In this sense, by installing the battery module of the present invention in a battery pack, a so-called cell-to-pack structured battery pack can be achieved.

[0053] The side frame 130 may be composed of a first side frame 130a coupled to one side of the battery cell stack and a second side frame 130b coupled to the other side. That is, the side frame 130 is coupled to both sides of the battery cell stack 110 to which the bus bar frame assembly 120 is not coupled. In other words, the side frame 130 is coupled to a wide side of the battery cell stack 110 (e.g., a pouch cell stack) on which no electrode lead is provided. When the battery module is installed in a battery pack and electrically operated, a swelling phenomenon in which the volume of the battery cell stack 110 changes in the width direction due to gas generated inside the battery cells may occur. The side frame 130 is coupled to both sides of the battery cell stack 110 in the width direction, and thus may absorb or support pressure caused by such swelling. In addition, the side frame 130 may also function to protect both sides of the battery cell stack 110 from external impact and to enhance the rigidity of the battery module. For this purpose, the side frame may be formed of a predetermined thickness and a predetermined material. For example, the side frame may be manufactured from a metal plate or plastic. Metal plates such as steel, stainless steel, and aluminum may be used. If necessary, the metal plate may be manufactured by an extrusion method. The extruded metal plate has a hollow channel formed therein in the extrusion direction. The weight of the side frame may be reduced by providing the metal plate with a hollow channel. In addition, the hollow channel may be used as a gas venting channel, a cooling channel, or the like in the battery pack, if necessary.

[0054] By coupling both side frames to the battery cell stack, the moduleless battery module can be conveniently transported and installed in the battery pack. That is, the side frames can be gripped with a jig to transport the battery module into the battery pack. In this case, the side frames are the parts to be gripped by the jig and serve as support members for supporting the battery cell stack.

[0055] In addition, the battery module of the present invention can be easily installed in the battery pack by connecting the side frame to the bottom of the battery pack. For this purpose, the side frame may have a predetermined number of through fastening holes 132 for fastening fastening members. FIG 3 shows that a plurality of through fastening holes are provided at predetermined intervals along the longitudinal direction of the side frame.

[0056] The side frame 130 is coupled to the busbar frame assembly 120. That is, the battery cell stack 110 is coupled to the busbar frame assembly 120, and the busbar frame assembly 120 is coupled to the side frames 130 on both sides of the stack 110, respectively, thereby obtaining a battery module 100 having a compact coupling structure. As a result, the battery cell stack 110 is surrounded by the busbar frame assembly 120 and the side frame 130, and is coupled to the busbar frame assembly 120 and the side frame 130, respectively. By coupling the side frame 130 to the busbar frame assembly 120, the load of the busbar frame assembly 120 applied to the electrode leads can be alleviated.

[0057] 3 and 5, one of the bus bar frame assembly 120 and the side frame 130 has a coupling protrusion 122, and the other has an insertion coupling portion 131. The coupling protrusion 122 is inserted into the insertion coupling portion 131, whereby the bus bar frame assembly 120 and the side frame 130 are coupled together.

[0058] In this embodiment, the busbar frame 121 has a coupling protrusion 122, and the side frame 130 has an insert coupling portion 131. However, conversely, the side frame 130 may have a coupling protrusion, and the busbar frame 121 may have an insert coupling portion corresponding to the coupling protrusion of the side frame 130. That is, the present invention is characterized in that the busbar frame assembly 120 and the side frame 130 are coupled to each other by fit coupling of the coupling protrusion 122 and the insert coupling portion 131. For such fit coupling, when one of the busbar frame assembly 120 and the side frame 130 has the coupling protrusion 122, the other has the insert coupling portion 131 corresponding to the coupling protrusion 122.

[0059] Referring again to FIG. 3, side frames 130 disposed on both sides of the battery cell stack 110 are coupled to the bus bar frame assembly 120.

[0060] At this time, the side frame 130 extends in the longitudinal direction L of the battery cell stack 110 longer than the length of the battery cell stack 110 so that the front and rear ends of the side frame 130 protrude from the front and rear faces of the battery cell stack 110, respectively. That is, the side frame 130 has a length longer than the battery cell stack 110, and the front and rear ends protruding from the battery cell stack 110 become joints with the bus bar frame assembly 120. In this way, since the length of the side frame 130 is formed longer than the battery cell stack, both side faces of the battery cell stack 110 are not entirely exposed to the outside, and the battery cell stack 110 can be more efficiently protected from side impacts.

[0061] The insert coupling parts 131 provided on the inner surfaces of the front and rear ends of the side frame 130 are coupled to the corresponding coupling protrusions 122 provided on both sides of the bus bar frame assembly 120. The coupling protrusions 122 may be forcefully fitted into the insert coupling parts 131 for coupling. In this case, the insert coupling parts 131 are coupling grooves into which the coupling protrusions 122 are fitted. The diameter of the coupling groove may be slightly smaller than the diameter of the coupling protrusions 122 so that the coupling protrusions 122 are forcefully fitted. Alternatively, the inner periphery of the coupling groove may be tapered so that the diameter gradually decreases. Thus, the outer periphery of the coupling protrusions 122 may be firmly fitted into the inner periphery of the coupling groove as it advances toward the inside of the coupling groove, and fixed.

[0062] The cross-sectional shape of the coupling protrusion 122 may be one of a circle, a rectangle, and a cross. In this case, the shape of the insert coupling part 131 may be a shape corresponding to the coupling protrusion 122. However, the present invention is not limited thereto, and even if the cross-sectional shape of the coupling protrusion 122 is a shape other than a circle, such as a rectangle or a cross, the insert coupling part 131 may be provided in a circular shape to reflect assembly tolerances. In this case, an angular end of the coupling protrusion 122 having a cross section, for example, a rectangle or a cross, inserted into the circular insert coupling part 131 may be coupled to the circular inner peripheral surface in a wedge shape. This allows the coupling protrusion 122 and the insert coupling part 131 to be more firmly coupled to each other.

[0063] 3 to 5 show that the bus bar frame 121 is provided with the coupling protrusion 122, and the end of the side frame is provided with the insert coupling portion 131. However, the present invention is not limited thereto. That is, the coupling protrusions or insert coupling portions may be formed on both sides of the insulating cover 123, not on the bus bar frame 121, and the corresponding insert coupling portions 131 or coupling protrusions may be formed on the inner sides of the front end and rear end of the side frame 130. In this case, the bus bar frame 121 is coupled to the insulating cover 123 to form the bus bar frame assembly 120, and the side frame 130 is coupled to the insulating cover 123 to couple the side frame 130 and the bus bar frame assembly 120 together.

[0064] 5, the bus bar frame assembly 120 has a coupling protrusion 122, and the side frame has an insert coupling portion 131. At this time, the insert coupling portion 131 may be a coupling groove, i.e., a groove with one side closed, as described above, or may be a hole penetrating the side frame.

[0065] The insertion joint 131 may be formed via a drill after manufacturing the busbar frame assembly 120 or the side frame 130 .

[0066] In this embodiment, the protruding length P of the coupling protrusion 122 is equal to or smaller than the thickness T of the side frame. That is, even if the coupling protrusion 122 is inserted into the insertion coupling portion 131, it does not penetrate to the outside of the side frame.

[0067] The coupling protrusion 122 and the insert coupling portion 131 may be provided on each of the coupling surfaces of the bus bar frame assembly 120 and the side frame 130. That is, the coupling protrusion 122 and the corresponding insert coupling portion 131 may be provided in pairs. However, in order to more stably couple the bus bar frame assembly 120 and the side frame 130, the coupling protrusion 122 and the insert coupling portion 131 may be provided in multiple pairs.

[0068] The coupling protrusions 122 are coupled to the insertion coupling parts 131, so that the bus bar frame assembly 120 and the side frame 130 are firmly coupled to each other, and a moduleless type battery module having a compact structure can be realized. In addition, the coupling protrusions 122 and the insertion coupling parts 131 act as a kind of reference point when assembling the battery module, and can improve the manufacturing efficiency of the battery module. For example, when the bus bar frame assembly 120 is coupled to the front and rear surfaces of the battery cell stack 110, the insertion coupling parts 131 provided on the inner surfaces of the front and rear ends of the side frame 130 are fitted into the coupling protrusions 122 provided on the bus bar frame assembly 120, and the positions of both side frames 130 relative to the battery cell stack 110 and the bus bar frame assembly 120 are naturally determined. In this sense, the coupling protrusions 122 and the insertion coupling parts 131 serve as a kind of reference point for determining the positions of the members to be coupled.

[0069] Referring again to FIG. 3, the first side frame 130a and the second side frame 130b are provided with through-fastening holes 132 extending in the height direction. One battery module 100 may be coupled to another adjacent battery module 100 through the through-fastening holes 132. In this case, a connection frame (not shown) may be further provided which is coupled to an upper surface of the first side frame 130a and an upper surface of the second side frame 130b of another adjacently disposed battery module. The connection frame may have fastening holes corresponding to the through-fastening holes 132. The connection frame may be disposed on upper surfaces of opposing side frames of the adjacently disposed battery modules, and separate fastening members may be inserted and passed through the fastening holes and the through-fastening holes to couple two adjacent battery modules.

[0070] FIG. 6 is a perspective view of a battery pack in which a battery module according to a first embodiment of the present invention is installed, FIG. 7 is a schematic view showing a process of installing the battery module according to the first embodiment of the present invention in the battery pack, FIG. 8 is a schematic view showing a process of installing a side frame of the battery module at the bottom of the battery pack, and FIG. 9 is a side cross-sectional view of FIG. 8.

[0071] 6 and 7, a battery pack 1000 of the present invention includes a plurality of battery modules 100 according to the first embodiment and a pack housing 1100 that accommodates the plurality of battery modules. The pack housing 1100 may include a bottom plate 1110 on which the battery modules are mounted, a side wall 1120 that surrounds the bottom plate, and an upper cover (not shown) that covers the battery modules 100. The bottom plate 1110 and the side wall 1120 may be combined to form a lower pack housing. Also, the upper cover may be referred to as an upper pack housing. In this specification, the upper cover is omitted from illustration for simplification of illustration. Also, the pack housing 1100 may include a center frame 1130 that crosses a center portion of the bottom plate 1110.

[0072] 7, the battery module 100 may be fixed to the pack housing 1100 by fastening side frames 130 [first side frame 130a and second side frame 130b] on both sides of the battery module 100 to a bottom plate 1110 of the pack housing. In addition, a thermally conductive resin layer 1140 is disposed between the open lower surface of the battery module 100 and the bottom plate.

[0073] 8, bottom fastening holes 1111 are provided on the bottom plate 1110 at positions corresponding to the through fastening holes 132 of the side frame 130. A separate fastening member may be inserted through and inserted into the through fastening holes 132 and the bottom fastening holes 1111, so that the side frame 130 of the battery module 100 may be installed on the bottom plate 1110. The fastening member may be a bolt B. For convenience of illustration, only the side frame 130 of the battery module is shown in FIG. 8.

[0074] Also, referring to FIG. 8, the bottom fastening holes 1111 are provided in two adjacent rows. Therefore, when the battery modules are installed on the bottom plate 1110, the side frames 130 of the adjacent battery modules 100 are in contact with each other. According to the present embodiment, since both side frames 130 of the battery modules 100 can be directly installed in the battery pack, there is no need to install a partition wall inside the pack as in the related art. Therefore, the structure of the battery pack can be simplified, and the space utilization rate inside the pack can be increased as described above. As a result, the energy density of the battery pack can be improved.

[0075] The number of through-holes 132 of the side frame 130 and the number of bottom fastening holes 1111 of the bottom plate 1110 shown in FIG. 8 can be suitably adjusted according to the design of the battery module or battery pack.

[0076] On the other hand, in battery pack design, not only energy density but also thermal management is an important design item.

[0077] The conventional battery pack 20 has a problem that the cooling path becomes complicated due to the module frame structure of the conventional battery module 10. When the cooling path becomes complicated, the cooling efficiency decreases, and therefore, it is necessary to solve this problem.

[0078] 9, a thermally conductive resin layer 1140 is disposed between the open lower surface of the battery module and the bottom plate 1110. That is, in the present invention, since the lower surface of the battery module 100 is open, the battery cell stack 110 and the thermally conductive resin layer 1140 can be in direct contact with each other. Therefore, the cooling path is simpler than that of the conventional battery pack 20, and the cooling efficiency can be further improved.

[0079] Second embodiment FIG. 10 is an exploded perspective view of a battery module according to a second embodiment of the present invention.

[0080] In the first embodiment, only the bus bar frame 121 is provided with the coupling protrusion 122, whereas in this embodiment, coupling protrusions 222 are provided on both side surfaces of the bus bar frame 221 and the insulating cover 223. As a result, the inner surfaces of the side frames 230 on both sides are also provided with insertion coupling portions 231 corresponding to the coupling protrusions 222 provided on the bus bar frame 221 and the insulating cover 223, respectively.

[0081] However, as described above, unlike FIG. 10, the side frame 230 may be provided with a coupling protrusion, and the bus bar frame 221 and the insulating cover 223 may be provided with an insertion coupling portion, respectively.

[0082] In this embodiment, since not only the bus bar frame 221 but also the insulating cover 223 are provided with the coupling protrusions 222, the side frame and the bus bar frame assembly 220 can be more firmly coupled to each other. Therefore, the rigidity of the module-less battery module according to the present invention can be improved.

[0083] Third embodiment FIG. 11 is a schematic view showing a process of coupling a bus bar frame assembly and a side frame in a battery module according to the third embodiment of the present invention.

[0084] This embodiment is different from the first and second embodiments in that the coupling protrusions 322 of the bus bar frame assembly 320 penetrate the side frame 330 and protrude to the outside.

[0085] 11, the bus bar frame assembly 320 has a coupling protrusion 322, and the side frame 330 has a corresponding insertion coupling portion 331. The insertion coupling portion 331 is a coupling hole through which the coupling protrusion 322 is inserted and passed.

[0086] At this time, the coupling protrusion 322 passes through the coupling hole and protrudes out of the coupling hole. This embodiment is characterized in that it includes a screw coupling member 322b that is screw-coupled with the coupling protrusion 322. To this end, a screw thread may be provided on the outer periphery of the protruding end 322a of the coupling protrusion 322. The screw coupling member 322b is screw-coupled to the end 322a of the coupling protrusion 322 and presses the outer surface of the side frame 330.

[0087] The screw coupling members 322b are fastened to the coupling protrusions 322 to prevent the side frame 330 and the bus bar frame assembly 320 from coming off. In addition, the screw coupling members 322b press the side frame 330 in the direction of the battery cell stack 110. Therefore, the side frame 330 and the bus bar frame assembly 320 can be more strongly coupled and fixed. In addition, since the side frame 330 is coupled to and supported by the bus bar frame assembly 320, it can more easily support the swelling pressure of the battery cell stack 110.

[0088] When the battery module according to the present embodiment is installed, a space is formed between two adjacent battery modules, spaced apart by a distance equal to the protruding distance of each of the coupling protrusions 322. Such a space can be used as a gas venting path or an air flow path of the battery pack, thereby making the heat management of the battery pack more efficient.

[0089] (Fourth embodiment) FIG. 12 is an exploded perspective view of a battery module according to a fourth embodiment of the present invention, FIG. 13 is a schematic diagram showing the connection relationship of a side frame for a battery module according to the fourth embodiment of the present invention, and FIG. 14 is a schematic diagram of the connection process of two battery modules according to the fourth embodiment of the present invention.

[0090] The battery module 400 according to the present embodiment differs in that the side frames 430 located on both sides have complementary structures that can be coupled to each other. The side frames 430 are composed of a first side frame 430a coupled to one side of the battery cell stack 110 and a second side frame 430b coupled to the other side, and the first side frame 430a and the second side frame 430b have complementary structures that can be interlocked with each other.

[0091] 13, the first side frame 430a has a first step portion 434a protruding from an upper portion of an outer side surface thereof. That is, a first protrusion 433a is formed on an upper portion of an outer side surface of the first side frame 430a. Therefore, a first step portion 434a is formed between the first protrusion 433a and a main body of the first side frame 430a.

[0092] The second side frame 430b has a second step portion 434b that protrudes from a lower portion of an outer side surface thereof and has a shape that engages with the first step portion. The second side frame 430b has a second protrusion 433b formed on a lower portion of an outer side surface. Therefore, a second step portion 434b is formed between the second protrusion 433b and a main body of the second side frame 430b. The first step portion 434a of the first side frame and the second step portion 434b of the second side frame of adjacent battery modules are engaged and coupled to each other, so that adjacent battery modules 400 can be fastened to each other.

[0093] In Fig. 13, the first protrusion 433a, the second protrusion 433b, the first step 434a, and the second step 434b are continuously formed along the longitudinal direction of the side frame 430. However, this is not limited thereto, and the first protrusion 433a, the second protrusion 433b, the first step 434a, and the second step 434b may be intermittently formed along the longitudinal direction of the side frame 430. In this case, the positions of the intermittently formed first step 434a and second step 434b need to be formed in the first side frame 430a and the second side frame 430b, respectively, so as to correspond to each other.

[0094] A first fastening through hole 432a extending in the height direction of the first side frame 430a is formed in the first protruding portion 433a and the first step portion 434a. A second fastening through hole 432b extending in the height direction of the second side frame 430b is formed in the second protruding portion 433b and the second step portion 434b.

[0095] The first and second through-holes 432a and 432b are formed in the first and second side frames 430a and 430b, respectively, so as to be aligned in the height direction.

[0096] 14, the first side frame 430a of one battery module 400 and the second side frame 430b of the adjacent battery module 400 face each other. The first step portion 434a and the second step portion 434b of the facing side frames are positioned to be engaged with each other. At this time, the first through fastening hole 432a and the second through fastening hole 432b are aligned to match in the height direction. Therefore, the first side frame 430a and the second side frame 430b of two adjacent battery modules 400 can be coupled to each other by coupling a fastening member through the aligned through fastening holes 432a and 432b. In this manner, the adjacent battery modules can be linked in the width direction to form a battery module assembly.

[0097] FIG. 15 is a schematic perspective view showing a battery module according to a fourth embodiment of the present invention installed in a battery pack, and FIG. 16 is a schematic view showing a process in which a side frame of the battery module according to the fourth embodiment of the present invention is installed at the bottom of the battery pack.

[0098] 15 and 16, the combination of the first side frame 430a and the second side frame 430b of adjacent battery modules forms a stack partition member 450 that separates adjacent battery cell stacks 110. In this embodiment, the stack partition member 450 is different from the first side frame 430a and the second side frame 430b of adjacent battery modules in that the stack partition member 450 is not a partition member pre-installed in the pack housing 2100, but is formed only by combining the battery modules.

[0099] As shown in FIG. 15, adjacent battery modules 400 may form two rows of battery module assemblies on both sides of the center frame 2130 by complementary coupling of opposing side frames 430a, 430b.

[0100] The battery module may be fixed to the pack housing 2100 by coupling a partition member 450 constituted by the side frames 430a, 430b to a bottom plate 2110 of the pack housing 2100. After aligning the first through-fastening hole 432a and the second through-fastening hole 432b to coincide with each other in the height direction, a fastening member B is coupled through the through-fastening holes 432a, 432b so that an end of the fastening member is coupled to the bottom plate 2110, thereby coupling the battery modules 400 to each other and coupling the battery modules 400 to the bottom plate 2110 simultaneously.

[0101] In this embodiment, adjacent battery modules 400 each include a side frame 430 that is complementary to each other. Thus, the battery modules 400 are coupled to each other as well as to the bottom plate 2110 within the battery pack 2000. Therefore, the battery modules 400 can be installed in the battery pack 2000 more stably and firmly.

[0102] 16, a thermally conductive resin layer 2140 is disposed between the open lower surface of the battery module 400 and the bottom plate. That is, in the present invention, since the lower surface of the battery module 400 is open, the battery cell stack 110 and the thermally conductive resin layer 2140 can be in direct contact with each other. Therefore, the cooling path is simpler than that of the conventional battery pack 20, and the cooling efficiency can be further improved.

[0103] In the battery pack 2000 of the present embodiment, there is no need to install a partition member in advance inside the battery pack because the first side frame 430a and the second side frame 430b of the adjacent battery modules are coupled to each other to form the laminated partition member 450. Therefore, in the present embodiment, the space utilization rate of the battery pack 2000 can be improved and the energy density of the battery pack can be further improved.

[0104] 16, in the battery pack 2000 in which the battery module 400 according to the present embodiment is installed, the side frames 430 of two adjacent battery modules 400 are engaged with each other to be coupled, so that the bottom fastening holes 2111 may be formed in a row. In addition, since the side frames 430 are engaged with each other, the number of fastening members may be relatively small. Therefore, the battery pack 2000 in which the battery module 400 according to the present embodiment is installed may further improve the energy density compared to the battery pack 1000 in which the battery modules 100, 200 according to other embodiments are installed.

[0105] Other configurations that overlap with other embodiments may be applied to the battery module 400 according to the present embodiment as they are, and therefore detailed description thereof will be omitted. For example, although the coupling protrusion 122 is shown to be provided only on the bus bar frame 121 in Fig. 12, the coupling protrusion 222 may be provided on the bus bar frame 221 and the insulating cover 223, respectively, as in the second embodiment. Furthermore, as in the third embodiment, a screw coupling member 322b coupled to the coupling protrusion 322 penetrating the side frame 330 may further be provided.

[0106] The above description is merely illustrative of the technical idea of ​​the present invention, and various modifications and variations may be made by those skilled in the art without departing from the essential characteristics of the present invention. Therefore, 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 scope equivalent thereto are interpreted as being included in the scope of the present invention.

[0107] Meanwhile, in this specification, terms indicating directions such as up, down, left, right, front, and back are used, but it is obvious that such terms are used merely for convenience of explanation and may change depending on the position of the target object, the position of the observer, etc. [Explanation of symbols]

[0108] 10: Conventional battery module 20: Conventional battery pack 100, 200, 400: Battery module 110: Battery cell stack 111: Battery cell 120, 220, 320: Busbar frame assembly 121, 221: Busbar frame 122, 222, 322: Joint protrusion 123, 223: Insulating cover 130, 230, 430: Both side frames 131, 231, 331: Insertion joint 132, 232, 432: Through fastening holes 433a: First protrusion 433b: Second protrusion 434a: First step 434b: Second step 1000, 2000: Battery pack 1100, 2100: Pack housing 1140, 2140: Thermally conductive resin layer

Claims

1. a battery cell stack in which a plurality of battery cells each having an electrode lead are stacked; a bus bar frame assembly coupled to the electrode lead; a side frame disposed on each side of the battery cell stack and coupled to the bus bar frame assembly, one of the bus bar frame assembly and the side frame has a coupling protrusion and the other has an insertion coupling portion, and the bus bar frame assembly and the side frame are coupled to each other by inserting the coupling protrusion into the insertion coupling portion; a battery module in which both upper and lower surfaces of the battery cell stack, except for a surface where the side frame and the bus bar frame assembly are joined, are open;

2. the bus bar frame assembly is coupled to a front surface and a rear surface of the battery cell stack, the bus bar frame assembly includes a through slit into which the electrode lead is inserted, 2. The battery module according to claim 1, wherein the electrode leads of the battery cells having different polarities that pass through the through slits are bent toward each other and coupled together, thereby fixing the battery cell stack to the bus bar frame assembly.

3. the side frame extends in a longitudinal direction of the battery cell stack longer than a length of the battery cell stack such that a front end portion and a rear end portion of the side frame protrude from the front surface and the rear surface of the battery cell stack, respectively; 3. The battery module according to claim 2, wherein the insertion coupling portions or the coupling protrusions provided on inner surfaces of the front end portion and the rear end portion of the side frame are coupled to corresponding coupling protrusions or the insertion coupling portions provided on both side surfaces of the bus bar frame assembly.

4. The bus bar frame assembly is A busbar frame having a busbar attached thereto; 2. The battery module according to claim 1, further comprising: an insulating cover coupled to the bus bar frame on a surface of the bus bar frame opposite to a surface facing the battery cell stack.

5. the side frame extends in a longitudinal direction of the battery cell stack longer than a length of the battery cell stack such that front and rear ends of the side frame protrude from a front surface and a rear surface of the battery cell stack, respectively; the coupling protrusion or the insertion coupling portion is provided on both sides of one of the bus bar frame and the insulation cover, 5. The battery module according to claim 4, wherein the insertion coupling portions or the coupling protrusions provided on the inner surfaces of the front and rear ends of the side frames are coupled to the corresponding coupling protrusions or the insertion coupling portions provided on the bus bar frame or the insulating cover.

6. the coupling protrusion or the insertion coupling portion is provided on both sides of the bus bar frame and the insulating cover, respectively; The battery module according to claim 5 , wherein the insertion coupling portion or the coupling protrusion of the side frame is coupled to the corresponding coupling protrusion or the insertion coupling portion provided on the bus bar frame and the insulating cover, respectively.

7. The battery module according to claim 1 , wherein a cross-sectional shape of the coupling protrusion is one of a circle, a rectangle, and a cross.

8. the bus bar frame assembly has the coupling protrusion, The side frame has the insertion joint, The battery module according to claim 3 , wherein the insertion coupling portion is a coupling groove into which the coupling protrusion is inserted and fitted.

9. the bus bar frame assembly has the coupling protrusion, The side frame has the insertion joint, The battery module according to claim 3 , wherein the insertion coupling portion is a coupling hole through which the coupling protrusion is inserted and passed.

10. The coupling protrusion passes through the coupling hole and protrudes out of the coupling hole, The battery module of claim 9 , further comprising a screw coupling member screwed to an end of the coupling protrusion protruding out of the coupling hole and pressing an outer surface of the side frame.

11. the side frame includes a first side frame coupled to one side of the battery cell stack and a second side frame coupled to the other side of the battery cell stack, The battery module according to claim 1 , wherein the first side frame and the second side frame are provided with through-holes extending in a height direction.

12. the side frame includes a first side frame coupled to one side of the battery cell stack and a second side frame coupled to the other side of the battery cell stack, The battery module according to claim 1 , wherein the first side frame and the second side frame have complementary structures that interlock with each other.

13. the first side frame has a first step portion that protrudes from an upper portion of an outer surface thereof, the second side frame has a second step portion that protrudes from a lower portion of an outer surface thereof and has a shape that engages with the first step portion, 13. The battery module of claim 12, wherein the first step portion of the first side frame and the second step portion of the second side frame of adjacent battery modules are engaged and coupled to each other, thereby fastening adjacent battery modules to each other.

14. A plurality of battery modules according to any one of claims 1 to 11; a pack housing that houses the plurality of battery modules; the side frame is fastened to a bottom plate of the pack housing, thereby fixing the battery module to the pack housing; a thermally conductive resin layer disposed between the open lower surface of the battery module and the bottom plate.

15. A plurality of battery modules according to claim 12 or 13; a pack housing that houses the plurality of battery modules; the first side frame and the second side frame of the adjacent battery module are engaged with each other to form a partition member that divides the adjacent battery cell stacks, the partition member is fastened to a bottom plate of the pack housing, thereby fixing the battery module to the pack housing; a thermally conductive resin layer disposed between the open lower surface of the battery module and the bottom plate.

Images