Rechargeable battery pack

Abstract

A rechargeable battery pack includes: a cell stack including a plurality of battery cells stacked in a first direction; the central frame comprises a first bottom plate and a first side wall which are integrally formed and supports the single body stack; and a first side frame and a second side frame each including a second bottom plate and a second side wall integrally formed, the second bottom plate coupled to the first bottom plate in a second direction crossing the first direction, the second side wall supporting a narrow cell side surface of the cell stack. The first bottom plate and the second bottom plate include a plurality of cooling water paths extending in the first direction and spaced apart from each other in the second direction.

Description

Technical Field

[0001] Aspects of embodiments of the present disclosure relate to a rechargeable battery pack. Background Art

[0002] Unlike primary batteries, rechargeable batteries are batteries designed to be repeatedly charged and discharged. Small-capacity rechargeable batteries are used in small portable electronic devices such as mobile phones, laptop computers, and camcorders. Rechargeable batteries with large capacity and high density are used as power sources for driving motors in hybrid vehicles and electric vehicles or for energy storage.

[0003] The rechargeable battery can be used as (or implemented as) a rechargeable battery module, which includes a plurality of battery cells connected together in series and / or connected in parallel to drive a motor that requires a relatively high energy density, such as a hybrid vehicle. In order to implement a relatively high-power rechargeable battery module (for example, for an electric vehicle), a plurality of rechargeable battery cells provided in a certain number and connected in a configuration that provides a required amount of electrical power are stacked in a frame to form a rechargeable battery module.

[0004] These rechargeable battery modules are connected in series and / or in parallel within a housing manufactured using various methods to form a rechargeable battery pack. Therefore, various types of rechargeable battery modules are being produced to provide rechargeable battery packs of various capacities.

[0005] In terms of energy capacity, a battery pack including a rechargeable battery module has limitations. A rechargeable battery pack that directly assembles battery cells without a rechargeable battery module can increase or maximize the energy density of the rechargeable battery pack. In addition, it is desirable to simplify the structure of the frame and the cooling part, enhance the rigidity of the frame and the cooling part, and lighten the frame and the cooling part. Summary of the invention

[0006] Embodiments of the present disclosure provide a rechargeable battery pack that simplifies the structure of a frame and a cooling part, enhances the rigidity of the frame and the cooling part, and lightens the frame and the cooling part. In addition, embodiments provide a rechargeable battery pack that increases or maximizes the energy density of the battery pack by stacking battery cells.

[0007] A rechargeable battery pack according to an embodiment of the present disclosure includes: a cell stack including a plurality of battery cells stacked in a first direction; a central frame including an integrally formed first bottom plate and a first side wall and supporting the cell stack; and a first side frame and a second side frame, each including an integrally formed second bottom plate and a second side wall, the second bottom plate being coupled to the first bottom plate in a second direction intersecting the first direction, the second side wall supporting a narrow cell side surface of the cell stack. The first bottom plate and the second bottom plate include a plurality of cooling water paths extending in the first direction and spaced apart from each other in the second direction.

[0008] The first base plate and the second base plate may include: an inflow balancer connected to the inlet of the cooling water path to balance the inflow of cooling water flow; an outflow balancer connected to the outlet of the cooling water path to balance the outflow of cooling water flow; and a reflux part connected to the cooling water path on the reflux side of the cooling water path to form a balance of cooling water reflux.

[0009] The inflow balancer may connect the inflow balancing channels together at a final inlet, each of the inflow balancing channels being connected to the inlet of the cooling water path, and the outflow balancer may connect the outflow balancing channels together at a final outlet, each of the outflow balancing channels being connected to the outlet of the cooling water path.

[0010] The return portion may include: a first return line connecting the outlet and the inlet of the cooling water path in the first bottom plate; and a second return line connecting the outlet and the inlet of the cooling water path in the second bottom plate.

[0011] The first return line may have a plurality of return holes, and may be a first return pipe welded to the first bottom plate and connected to the cooling water path through a rubber seal.

[0012] The second return line may be provided at one side of the first return pipe in the first direction, may have a plurality of return holes, and may be a second return pipe welded to the second bottom plate and connected to the cooling water path through a rubber seal.

[0013] The inflow balancing channel of the inflow balancer can be connected to the cooling water path in the second bottom plate of the first side frame and to half of the cooling water path in the first bottom plate of the center frame, and the outflow balancing channel of the outflow balancer can be connected to the cooling water path in the second bottom plate of the second side frame and the remaining half of the cooling water path in the first bottom plate of the center frame.

[0014] The inflow balancing channel of the inflow balancer may form a symmetrical structure in the second direction.

[0015] The outflow balancing channel of the outflow balancer may form a symmetrical structure in the second direction.

[0016] The inflow balancing channel of the inflow balancer may have a length that gradually decreases or increases from the outside toward the center in the second direction, respectively.

[0017] The outflow balancing channel of the outflow balancer may have a length that gradually decreases or increases from the outside toward the center in the second direction, respectively.

[0018] The first bottom plate and the second bottom plate may be welded at a welding bottom surface having a first width, a welding top surface having a second width greater than the first width, and a welding bevel connecting the welding bottom surface and the welding top surface.

[0019] The first bottom plate and the second bottom plate may be connected by coupling a coupling protrusion and a coupling groove formed along the first direction.

[0020] The coupling protrusion and the coupling groove may be fixed by welding in a coupled state.

[0021] The first base plate may have a narrow lower surface and a wide upper surface so that the side surface of the first base plate is inclined downward, the second base plate may have a wide lower surface and a narrow upper surface so that the side surface of the second base plate is inclined upward, and the downward-inclined side surface of the first base plate may be connected to the upward-inclined side surface of the second base plate on the opposite side of the first base plate in the second direction.

[0022] The rechargeable battery pack may further include first and second end frames respectively coupled to opposite ends of the center frame, the first side frame, and the second side frame in the first direction to support wide cell side surfaces of the cell stack.

[0023] The rechargeable battery pack according to the embodiment integrally forms a central frame and first and second side frames, and includes a plurality of cooling water paths in the first and second bottom plates, thereby simplifying the structure of the frame and the cooling part, enhancing the rigidity of the frame and the cooling part, and lightening the frame and the cooling part.

[0024] Furthermore, according to the embodiment, a cell stack including a plurality of battery cells stacked in a first direction is provided between the first end frame and the second end frame, and thus, the battery pack energy density may be increased or maximized. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 is a perspective view of a rechargeable battery pack according to an embodiment.

[0026] Figure 2 yes Figure 1 Exploded perspective view of a pack frame of a rechargeable battery pack shown in FIG.

[0027] Figure 3 Is the stacked Figure 1 A perspective view of a cell stack of a battery cell shown in FIG.

[0028] Figure 4 It is along Figure 2 A cross-sectional view taken along line IV-IV.

[0029] Figure 5 It is along Figure 2 A cross-sectional view of the group frames after being connected together, taken along line VV.

[0030] Figure 6 is a cross-sectional view of a group frame coupling portion according to another embodiment.

[0031] Figure 7 is a schematic diagram of a group frame connection portion according to another embodiment.

[0032] Figure 8 is formed in Figure 1 and Figure 2 A top plan view of the cooling water paths in the stack frame shown in FIG.

[0033] Fig. 9 Is applied to Figure 5 A perspective view of the flow balancers at the inlet and outlet of the cooling water path in the group frame is shown in FIG.

[0034] Fig.10 is a top plan view of a flow balancer according to another embodiment.

[0035] Fig.11 is a top plan view of a flow balancer according to another embodiment.

[0036] Fig.12 is installed on the entry and / or exit side of the path in the group frame Fig. 9 A top plan view of the flow balancer shown in FIG.

[0037] Fig.13 yes Figure 8 An exploded perspective view of the return portion of the cooling water path shown in FIG.

[0038] Fig.14 yes Fig.13 An enlarged exploded perspective view of a portion of.

[0039] Fig.15 yes Fig.13 An enlarged top plan view of a portion of the.

[0040] Fig.16 is an image of a computer-aided engineering (CAE) analysis result when a flow balancer is used.

[0041] Fig.17 is a graph depicting the inlet area flow distribution of each cooling channel when a flow balancer is used.

[0042] Fig.18 is a graph depicting the outlet area flow distribution of each cooling channel when a flow balancer is used.

[0043] Fig.19 is a graph describing improvement in crushing characteristics in the x-axis direction as a result of CAE analysis when a structure in which a frame and a cooling water path are integrated according to an embodiment is applied.

[0044] Fig. 20 is a graph describing the crushing characteristics in the x-axis direction as a result of CAE analysis when a structure in which a frame according to a comparative example and a cooling water path are not integrated is applied. DETAILED DESCRIPTION

[0045] Hereinafter, the present disclosure will be described more fully with reference to the accompanying drawings showing embodiments of the present disclosure. As will be appreciated by those skilled in the art, the described embodiments may be modified in various ways, all without departing from the spirit or scope of the present disclosure. The accompanying drawings and descriptions should be regarded as illustrative and non-restrictive in nature.

[0046] It will be understood that when an element or layer is referred to as being "on," "connected to," or "coupled to" another element or layer, it may be directly on, connected to, or coupled to the other element or layer, or one or more intervening elements or layers may also be present. When an element or layer is referred to as being "directly on," "directly connected to," or "directly coupled to" another element or layer, there are no intervening elements or layers. For example, when a first element is described as being "coupled to" or "connected to" a second element, the first element may be directly coupled to or connected to the second element, or the first element may be indirectly coupled to or connected to the second element via one or more intervening elements.

[0047] In the figure, for the clarity of illustration, the size of various elements, layers, etc. can be enlarged. The same reference numerals indicate the same elements. As used herein, the term "and / or" includes any and all combinations of one or more related listed items. In addition, the "may" used when describing the embodiments of the present disclosure relates to "one or more embodiments of the present disclosure". When the expressions such as "at least one of" and "any one of" are after a column of elements, the whole column of elements is modified, and the single element in the column is not modified. For example, the expression "at least one of a, b and c" means only a, only b, only c, both a and b, both a and c, both b and c, all of a, b and c or its variant. As used herein, the term "use" can be regarded as synonymous with the term "utilize". As used herein, the terms "substantially", "about" and similar terms are used as approximate terms rather than as degree terms, and are intended to take into account the inherent changes in measured values ​​or calculated values ​​that will be recognized by those of ordinary skill in the art.

[0048] It will be understood that although the terms "first," "second," "third," etc., may be used herein to describe various elements, components, regions, layers, and / or sections, these elements, components, regions, layers, and / or sections should not be limited by these terms. These terms are used to distinguish one element, component, region, layer, or section from another element, component, region, layer, or section. Thus, a first element, component, region, layer, or section discussed below may be referred to as a second element, component, region, layer, or section without departing from the teachings of the example embodiments.

[0049] For ease of description, spatially relative terms such as "below", "below", "down", "above", "on", etc. may be used herein to describe the relationship between an element or feature and another element or feature as illustrated in the figure. It will be understood that these spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation depicted in the figure. For example, if the device in the figure is turned over, the elements described as being "below" or "below" other elements or features will then be oriented as being "above" or "on" other elements or features. Therefore, the term "below" can include both above and below orientations. The device can be oriented in other ways (rotated 90 degrees or in other orientations), and the spatially relative descriptors used herein should be interpreted accordingly.

[0050] The terms used herein are for the purpose of describing the embodiments of the present disclosure and are not intended to limit the present disclosure. As used herein, the singular form "a" is also intended to include the plural form, unless the context clearly states otherwise. It will be further understood that the terms "include" and / or "comprise" when used in this specification specify the presence of stated features, integers, steps, operations, elements and / or parts, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, parts and / or their groups.

[0051] Figure 1 is a perspective view of a rechargeable battery pack according to an embodiment, and Figure 2 yes Figure 1 An exploded perspective view of a pack frame of a rechargeable battery pack shown in FIG. Figure 1 and Figure 2 , a rechargeable battery pack according to an embodiment includes a plurality of cell stacks 100 and a pack frame 200 in which the cell stacks 100 are mounted.

[0052] The group frame 200 includes a center frame 10, a first side frame 21, a second side frame 22, a first end frame 31, and a second end frame 32. When the length of the group frame 200 is long in a first direction (eg, x-axis direction), the group frame 200 may further include a cross center frame 40.

[0053] The cross center frame 40 is combined with the center frame 10 and the first and second side frames 21 and 22 in the middle of a first direction (eg, x-axis direction) to support wide cell side surfaces of different cell stacks 100 at both sides in the first direction.

[0054] The center frame 10 and the first and second side frames 21 and 22 are extruded and cut, so that they can accommodate various sizes of the single stack pieces 100 according to the length in the first direction (e.g., the x-axis direction). For example, the center frame 10, the first and second side frames 21 and 22 can be cut into appropriate lengths according to the length of the single stack piece 100 in the first direction, and then combined to form the group frame 200.

[0055] In the group frame 200 , the center frame 10 , the first side frame 21 , and the second side frame 22 are formed using an extruded profile structure, and thus, an assembly space for the unit stack 100 can be easily formed.

[0056] The cross-sectional structure of the extruded profile and the length variation of the center frame 10 and the first and second side frames 21 and 22 may allow for easy adjustment (eg, size or length adjustment) in response to various energy sizes of electric vehicles designed for various unit stack sizes.

[0057] The center frame 10 includes a first bottom plate 11 and a first side wall 12 formed integrally and supports the single stack 100. The first side wall 12 is formed to be long in a first direction (e.g., x-axis direction) (e.g., mainly extending in the first direction) and has a height from the center of the first bottom plate 11 in a second direction (e.g., y-axis direction) to a third direction (e.g., z-axis direction). Therefore, there is no side wall at both ends of the second direction (e.g., y-axis direction) of the center frame 10 to form an open first bottom plate 11.

[0058] The first side frame 21 and the second side frame 22 are coupled to the center frame 10 in a second direction (e.g., y-axis direction) that crosses (e.g., intersects) the first direction (e.g., x-axis direction). The first side frame 21 and the second side frame 22 each include a second bottom plate 211, 221 and a second side wall 212, 222 that are integrally formed, and the second side wall 212, 222 supports a narrow cell side surface (e.g., in the xz plane) of the cell stack 100. The second bottom plates 211, 221 are coupled to both sides (e.g., opposite sides) of the first bottom plate 11 in the second direction.

[0059] The first end frame 31 and the second end frame 32 are coupled to the center frame 10 and the first side frame 21 and the second side frame 22 at opposite ends in a first direction (e.g., x-axis direction) to support a wide monomer side surface (e.g., in the yz plane) and provide (or form) a cooling water inlet side and an outlet side of the monomer stack 100.

[0060] Figure 3 Is the stacked Figure 1 A perspective view of a cell stack of a battery cell shown in FIG. Figure 1 and Figure 3 The cell stack 100 is formed by stacking a plurality of battery cells 101 in a first direction (eg, an x-axis direction).

[0061] The cell stack 100 holds the battery cells 101 in a stacked state in a space formed by (or between) a pair of side cases 110 disposed apart from each other in the second direction and a pair of end cases 120 disposed apart from each other in the first direction before being mounted to the group frame 200. The battery cell 101 may be a rectangular rechargeable battery having a wide cell side surface (e.g., in the yz plane) and a narrow cell side surface (e.g., in the xz plane), and having electrode terminals 102, 103 on the top side.

[0062] In the battery cell 101, the wide cell side surfaces face both sides of the battery cell 101 in a first direction (e.g., x-axis direction), and the narrow cell side surfaces face both sides of the battery cell 101 in a second direction (e.g., y-axis direction) intersecting the first direction (e.g., x-axis direction). The electrode terminals 102, 103 are oriented upward (or face or extend upward) in a third direction (e.g., z-axis direction) orthogonal to the first direction and the second direction (e.g., x-axis direction and y-axis direction).

[0063] Figure 4 It is along Figure 2 A cross-sectional view taken along line IV-IV of FIG. Figure 2 and Figure 4 The first side frame 21 and the second side frame 22 integrally form the second bottom plate 211 , 221 and the second side walls 212 , 222 , and the center frame 10 integrally forms the first bottom plate 11 and the first side wall 12 .

[0064] The second bottom plate 221 has a plurality of cooling water paths 50 extending in a first direction (e.g., x-axis direction) and arranged at a distance (e.g., spaced apart) from each other in a second direction (e.g., y-axis direction) and configured to cool water flowing therethrough. The cooling water paths 50 have the same structure in the second bottom plates 211, 221 of the first side frame 21 and the second side frame 22 and in the first bottom plate 11 of the center frame 10, and therefore, the cooling water paths 50 in the second side frame 22 are illustrated only as an example. Figure 8 The entire configuration of the cooling water path 50 is schematically illustrated in FIG.

[0065] When the first and second bottom plates 11, 211, 221 are provided with the cooling water path 50, the cooling portion including the cooling water path 50 is formed integrally with the first and second bottom plates 11, 211, 221. Accordingly, the cooling portion is formed integrally with the group frame 200. In such an embodiment, the structure of the cooling portion is simplified, the rigidity of the group frame 200 and the cooling portion is enhanced, and the group frame 200 and the cooling portion can be made lighter.

[0066] Hereinafter, the combination and connection structure of the first bottom plate 11 and the second bottom plates 211 and 221 will be described in more detail. Figure 5 It is along Figure 2 A cross-sectional view of the group frame after connection (eg, in an unexploded state) taken along line VV. Figure 5In the center frame 10 and the second side frame 22, for example, the first bottom plate 11 and the second bottom plate 221 are welded using a welding bottom surface having a first width W1, a welding top surface having a second width W2 greater than the first width W1, and a welding slope connecting the bottom surface and the top surface (or extending between them). The welding portion W may form a downward wedge-shaped structure to enhance the welding bonding strength between the first bottom plate 11 and the second bottom plate 221.

[0067] Figure 6 is a cross-sectional view of a group frame coupling portion according to another embodiment. Figure 6 For example, in the center frame 610 and the second side frame 62, the first bottom plate 611 and the second bottom plate 621 are pressed, and therefore, they are connected by coupling the coupling protrusion 63 and the coupling groove 64 formed along the first direction (e.g., the x-axis direction). In addition, the coupling protrusion 63 and the coupling groove 64 are further fixed by welding WP while being in a combined state, so that relative movement in the first direction and the second direction can be prevented. The welding WP may be spot welding at a certain interval (e.g., a predetermined interval or a repeated interval) along the first direction.

[0068] Figure 7 Schematic diagram of a group frame connection part according to another embodiment. Figure 7 The first bottom plate 711 of the center frame 710 has a relatively narrow lower surface and a relatively wide upper surface, and therefore, its side surface is inclined downward. The second bottom plate 731 of the first side frame 73 and the second bottom plate 741 of the second side frame 74 have a relatively wide lower surface and a relatively narrow upper surface, and therefore, their side surfaces are inclined upward.

[0069] The downwardly inclined side surface of the first bottom plate 711 is coupled to the upwardly inclined side surfaces of the second bottom plates 731 and 741 disposed on the opposite side of the first bottom plate 711 in the second direction (e.g., the y-axis direction). Because the upwardly inclined side surfaces of the second bottom plates 731 and 741 support the downwardly inclined side surfaces of the first bottom plate 711, the bonding strength of the first bottom plate 711 and the second bottom plates 731 and 741 can be stabilized, and when spot welding is used, the bonding strength can be further enhanced.

[0070] Hereinafter, the cooling portions of the first bottom plate 11 and the second bottom plates 211 , 221 will be described in more detail. Figure 8 is formed in Figure 1 and Figure 2 A top plan view of the cooling water path in the group frame shown in FIG. Figure 8 The first bottom plate 11 and the second bottom plates 211 , 221 include an inflow balancer 41 , an outflow balancer 42 , and a return portion 43 connected to a cooling water path 50 .

[0071] The inflow balancer 41 is configured to connect to the inlet of the cooling water path 50, thereby balancing (e.g., distributing) the inflowing cooling water flow. The outflow balancer 42 is configured to connect to the outlet of the cooling water path 50, thereby balancing (e.g., collecting) the outflowing cooling water flow. The return portion 43 is configured to connect to the cooling water path 50 at the return side of the cooling water path 50, thereby forming a balance of cooling water return.

[0072] The inflow balancer 41 connects one final inlet 412 to the inflow balancing channels 411 respectively connected to the inlets of the cooling water path 50. The outflow balancer 42 connects the outflow balancing channels 421 respectively connected to the outlets of the cooling water path 50 to one final outlet 422.

[0073] The return portion 43 includes a first return line 431 and a second return line 432. The first return line 431 connects the outlet and the inlet of the cooling water path 50 formed in the first bottom plate 11 to each other. The second return line 432 connects the outlet and the inlet of the cooling water path 50 formed in the second bottom plate 211 of the first side frame 21 and the second bottom plate 221 of the second side frame 22 on the return side.

[0074] Fig.13 yes Figure 8 An exploded perspective view of the return portion of the cooling water path shown in, Fig.14 yes Fig.13 an enlarged exploded perspective view of a portion of Fig.15 yes Fig.13 An enlarged top plan view of a connecting portion in a portion of FIG.

[0075] refer to Figure 13 to Figure 15 The first return line 431 has a plurality of return holes (eg, return openings) H1 and is formed as a first return pipe 431 connected to the cooling water path 50 through a rubber seal S1 and welded to the first base plate 11 .

[0076] The second return line 432 is arranged on one side of the first return pipe 431 in the first direction (for example, the x-axis direction), has a plurality of return holes (for example, return openings) H2, and is formed as a second return pipe 432 connected to the cooling water path 50 through a rubber seal S2 and welded to the second base plate 211, 221.

[0077] For ease of description, the same reference numerals are assigned to the first and second return lines 431 and 432 and the first and second return pipes 431 and 432. The first and second return pipes 431 and 432 are welded to the first and second bottom plates 11 and 211, 221. In such an embodiment, the seals S1 and S2 are compressed to seal the connection between the cooling water path 50 and the return holes H1 and H2.

[0078] As an example, when the center frame 10 and the first and second side frames 21 and 22 are extruded aluminum, the first and second return pipes 431 and 432 are formed of aluminum pipes to improve welding performance.

[0079] Return to reference Figure 8 The inflow balancing channel 411 of the inflow balancer 41 is connected to the cooling water path 50 in the second bottom plate 211 of the first side frame 21 and is connected to a half of the cooling water path 50 in the first bottom plate 11 of the center frame 10 .

[0080] The outflow balancing channel 421 of the outflow balancer 42 is connected to the cooling water path 50 in the second bottom plate 221 of the second side frame 22 and to the remaining half of the cooling water path 50 in the first bottom plate 11 of the center frame 10 .

[0081] like Figure 8 As shown, the inflow balancing channel 411 of the inflow balancer 41 and the outflow balancing channel 421 of the outflow balancer 42 may be formed to have the same structure.

[0082] Fig. 9 Is applied to Figure 5 A perspective view of the flow balancers at the inlet and outlet of the cooling water path in the group frame shown in FIG. Fig. 9 The inflow balancing channels 411 of the inflow balancer 41 form a symmetrical structure in the second direction (eg, the y-axis direction) and are connected as one (eg, connected together) at the final inlet 412 . Low-temperature cooling water flows into the final inlet 412 .

[0083] The outflow balancing channels 421 of the outflow balancer 42 form a symmetrical structure in the second direction (eg, the y-axis direction) and are connected as one (eg, connected together) at the final outlet 422 . The high-temperature cooling water flows out through the final outlet 422 .

[0084] Therefore, the low-temperature cooling water flowing into the inflow balancer 41 is first heated through the cooling water path 50 and second heated through the first and second return lines 431 and 432 and the cooling water path 50. The heated high-temperature cooling water flows out through the outflow balancer 42.

[0085] Fig.10 is a top plan view of a flow balancer according to another embodiment. Fig.10, the inflow balancing channel 451 of the inflow balancer 45 may have a channel length that gradually shortens or lengthens from the outside toward the center in the second direction (e.g., the y-axis direction). The channel length of the outflow balancing channel 461 of the outflow balancer 46 may gradually shorten or lengthen from the outside toward the center in the second direction (e.g., the y-axis direction). The inflow balancing channel 451 and the outflow balancing channel 461 may have the same width or may have widths of approximately similar size.

[0086] Fig.11 is a top plan view of a flow balancer according to another embodiment. Fig.11 , the inflow balancing channel 471 of the inflow balancer 47 may have a channel length that gradually shortens or lengthens from the outside toward the center in the second direction (e.g., the y-axis direction). The channel length of the outflow balancing channel 481 of the outflow balancer 48 may gradually shorten or lengthen from the outside toward the center in the second direction (e.g., the y-axis direction). The inflow balancing channel 471 and the outflow balancing channel 481 may be formed to have a relatively large width on the cooling water path 50 side and a relatively narrow width on the final inlet 412 or the final outlet 422 side.

[0087] Fig.12 yes Fig. 9 The flow balancer shown in FIG. is a top plan view of a state where it is installed on the inlet and / or outlet side of the path in the group frame. Fig.12 , the inflow balancer 41 is installed on one side of the first side frame 21 and the center frame 10 and assembled thereto by welding, and a sealing structure is formed on the lower surfaces of the second bottom plate 211 and the first bottom plate 11 using a sealing member S41 provided between the second bottom plate 211 and the first bottom plate 11. In such an embodiment, the inflow balance channel 411 is connected to the cooling water path 50.

[0088] The outflow balancer 42 is installed on one side of the second side frame 22 and the center frame 10 and assembled thereto by welding, and a sealing structure is formed on the lower surfaces of the second bottom plate 211 and the first bottom plate 11 using a sealing member S42 disposed between the second bottom plate 211 and the first bottom plate 11. In such an embodiment, the outflow balancing channel 421 is connected to the cooling water path 50.

[0089] Fig.16 is an image of the results of a computer-aided engineering (CAE) analysis when a flow balancer is used. Specifically, Fig.16 The image shows that when using Fig.10 The CAE analysis results when the flow flows into the balancer 45 and out of the balancer 46 are shown in FIG.

[0090] like Fig.16As seen in the figure, similar temperature distribution occurs in the inlet balancer 45 and the outlet balancer 46 and symmetrical temperature distribution occurs in the second direction (e.g., the y-axis direction), and similar temperature distribution occurs in the cooling water path 50 connected to the inlet balancer 45 and the cooling water path 50 connected to the outflow balancer 46 and symmetrical temperature distribution occurs in the second direction (e.g., the y-axis direction).

[0091] Fig.17 is a graph describing the inlet area flow distribution of each cooling channel when a flow balancer is used, and Fig.18 is a graph depicting the outlet area flow distribution of each cooling channel when a flow balancer is used.

[0092] refer to Fig.17 and Fig.18 , a similar flow distribution is achieved between the inflow balancing channels 451 of the inflow balancer 45, and a similar flow distribution is achieved between the outflow balancing channels 461 of the outflow balancer 46.

[0093] Further, the flow distribution flowing into the balancer 45 and the flow distribution flowing out of the balancer 46 are symmetrical to each other in the second direction (e.g., the y-axis direction). In addition, symmetrical temperature distribution appears in the first return line 431 and the second return line 432 in the second direction (e.g., the y-axis direction).

[0094] Fig.19 is a diagram illustrating improvement in crushing characteristics in the x-axis direction as a result of CAE analysis in a structure in which a frame and a cooling water path are integrated according to an embodiment of the present disclosure, and Fig. 20 is a graph describing the crushing characteristics in the x-axis direction as a result of CAE analysis when a structure in which a frame according to a comparative example and a cooling water path are not integrated is applied.

[0095] In the group frame 200 , according to an embodiment, a cooling water path 50 is integrally formed in the first and second bottom plates 11 , 211 , 221 , and the inflow balancer 45 , the outflow balancer 46 , the first return pipe 431 and the second return pipe 432 are connected to the cooling water path 50 .

[0096] like Fig.19 As seen in FIG. 1 , the x-axis direction crushing characteristics of the rechargeable battery pack according to the embodiment in which the cooling portion is integrally formed in the pack frame are improved compared to the comparative example in which the cooling portion is separately formed.

[0097] In the comparative example (see Fig. 20 ), the group frame is crushed under the reaction force of 80 to 100 kN. Fig.19, the displacement of the group frame 200 is 4 mm under the reaction force of 100 kN, and the displacement of the group frame 200 is 23 mm under the reaction force of 200 kN.

[0098] The rechargeable battery pack according to an embodiment may further include a pack cover mounted on the first and second side frames 21 and 22 and the first and second end frames 31 and 32. The pack cover covers bus bars electrically connecting the electrode terminals 102 and 103 of the battery cells 101.

[0099] Return to reference Figure 1 and Figure 2 In the group frame 200, the first side frame 21 and the second side frame 22 are formed to be long along the first direction (e.g., x-axis direction) on the outer side of the group frame 200 in the second direction (e.g., y-axis direction), and can be installed on the vehicle as fastening members by flanges.

[0100] Although the embodiments of the present disclosure have been described above, the present disclosure is not limited thereto, and various modifications may be made and implemented within the scope of the claims and their equivalents, the detailed description, and the accompanying drawings, which all fall within the scope of the present disclosure.

[0101] Description of some reference numerals:

[0102] 10: Central frame 11: First base plate

[0103] 12: First side wall 21: First side frame

[0104] 22: Second side frame 31: First end frame

[0105] 32: Second end frame 40: Cross center frame

[0106] 41: Inflow balancer 42: Outflow balancer

[0107] 43: Reflux part 45, 47: Flow into the balancer

[0108] 46, 48: Outflow balancer 50: Cooling water path

[0109] 63: connection protrusion 64: connection groove

[0110] 73, 74: first side frame, second side frame 100: single stacking member

[0111] 101: Battery cell 102, 103: Electrode terminals

[0112] 200: assembly frame 211, 221: second bottom plate

[0113] 212, 222: Second side wall 411: Inflow balance channel

[0114] 412: Final inlet 421: Outflow balance channel

[0115] 422: Final outlet 431: First return line (pipe)

[0116] 432: Second return line (tube) 451, 471: Inflow balance channel

[0117] 461, 481: outflow balance channel 610: center frame

[0118] 611: first bottom plate 621: second bottom plate

[0119] 710: Central frame 711: First bottom plate

[0120] 731, 741: Second bottom plate H1, H2: reflux hole

[0121] S1, S2: rubber seals S41, S42: sealing components

[0122] W: welding part W1: first width

[0123] W2: Second Width WP: Welding

Claims

1. A rechargeable battery pack comprising: a cell stack including a plurality of battery cells stacked in a first direction; a central frame including an integrally formed first bottom plate and first side wall and supporting the single body stack; as well as a first side frame and a second side frame, each including an integrally formed second bottom plate and a second side wall, the second bottom plate being coupled to the first bottom plate in a second direction intersecting the first direction, the second side wall supporting a narrow cell side surface of the cell stack, The first bottom plate and the second bottom plate include a plurality of cooling water paths extending in the first direction and spaced apart from each other in the second direction.

2. The rechargeable battery pack according to claim 1, wherein the first bottom plate and the second bottom plate comprise: an inflow balancer connected to the inlet of the cooling water path to balance the inflowing cooling water flow; an outflow balancer connected to the outlet of the cooling water path to balance the outflowing cooling water flow; and The return portion is connected to the cooling water path at the return side of the cooling water path to form a balance of cooling water return.

3. The rechargeable battery pack according to claim 2, wherein the inflow balancer connects inflow balancing channels together at a final inlet, each of the inflow balancing channels being connected to the inlet of the cooling water path, and The outflow balancer connects outflow balancing channels together at a final outlet, each of the outflow balancing channels being connected to the outlet of the cooling water path.

4. The rechargeable battery pack according to claim 3, wherein the reflux portion comprises: a first return line connecting the outlet and the inlet of the cooling water path formed in the first bottom plate; as well as The second return line connects the outlet and the inlet of the cooling water path formed in the second bottom plate. 5 . The rechargeable battery pack according to claim 4 , wherein the first return line has a plurality of return holes and is a first return pipe welded to the first bottom plate and connected to the cooling water path through a rubber seal.

6. The rechargeable battery pack according to claim 5, wherein the second return line has a plurality of return holes on one side of the first return pipe in the first direction, and is a second return pipe connected to the cooling water path through a rubber seal and welded to the second bottom plate.

7. The rechargeable battery pack according to claim 3, wherein the inflow balancing channel of the inflow balancer is connected to the cooling water path in the second bottom plate of the first side frame and to a half of the cooling water path in the first bottom plate of the center frame, and wherein the outflow balancing channel of the outflow balancer is connected to the cooling water path in the second bottom plate of the second side frame and to the remaining half of the cooling water path in the first bottom plate of the center frame. 8 . The rechargeable battery pack according to claim 7 , wherein the inflow balancing channel of the inflow balancer forms a symmetrical structure in the second direction. 9 . The rechargeable battery pack according to claim 7 , wherein the outflow balancing channel of the outflow balancer forms a symmetrical structure in the second direction. 10 . The rechargeable battery pack of claim 7 , wherein the inflow balancing channel of the inflow balancer has a length that gradually decreases or increases from an outer side toward a center in the second direction, respectively. 11 . The rechargeable battery pack of claim 7 , wherein the outflow balancing channel of the outflow balancer has a length that gradually decreases or increases from an outer side toward a center in the second direction, respectively.

12. The rechargeable battery pack according to claim 1, wherein the first bottom plate and the second bottom plate are welded to form a weld bottom surface having a first width, a weld top surface having a second width greater than the first width, and a weld bevel connecting the weld bottom surface and the weld top surface. 13 . The rechargeable battery pack of claim 1 , wherein the first bottom plate and the second bottom plate are connected by coupling a coupling protrusion and a coupling groove formed along the first direction. 14 . The rechargeable battery pack of claim 13 , wherein the coupling protrusion and the coupling groove are fixed by welding in a coupled state.

15. The rechargeable battery pack according to claim 1, wherein the first bottom plate has a narrow lower surface and a wide upper surface such that a side surface of the first bottom plate is inclined downward, wherein the second bottom plate has a wide lower surface and a narrow upper surface, so that the side surface of the second bottom plate is inclined upward, and wherein the downwardly inclined side surface of the first bottom plate is coupled to the upwardly inclined side surface of the second bottom plate on an opposite side of the first bottom plate in the second direction.

16. The rechargeable battery pack of claim 1, further comprising a first end frame and a second end frame respectively coupled to opposite ends of the center frame, the first side frame, and the second side frame in the first direction to support wide cell side surfaces of the cell stack.

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