Battery pack

Abstract

The present invention relates to a battery pack accommodating a plurality of cell assemblies, comprising: a pack case providing a space in which the cell assemblies are seated; the pack case including a base plate supporting lower portions of the cell assemblies; and a partition wall interposed between a pair of adjacently arranged cell assemblies such that each cell assembly is separated and connected to the base plate; the partition wall being connected to the base plate by a connecting member vertically penetrating a lower end of the base plate.

Description

[Technical Field]

[0001] The present invention relates to a battery pack, characterized in that a base plate supporting the lower ends of a cell assembly and a partition wall interposed between a pair of adjacently arranged cell assemblies so as to separate the cell assemblies are fixed by screwing together with a connecting member.

[0002] This application claims the benefit of priority based on Korean Patent Application No. 10-2022-0167128, dated December 2, 2022, Korean Patent Application No. 10-2023-0035452, dated March 17, 2023, and Korean Patent Application No. 10-2023-0172135, dated December 1, 2023, and all contents disclosed in the documents of said Korean patent applications are incorporated herein by reference. [Background technology]

[0003] Types of secondary batteries include lithium ion batteries, lithium polymer batteries, nickel cadmium batteries, nickel metal hydride batteries, and nickel zinc batteries. The operating voltage of such a unit secondary battery cell, i.e., a unit battery cell, is approximately 2.5V to 4.2V. Therefore, if a higher output voltage is required, a battery pack may be configured by connecting a plurality of battery cells in series. Alternatively, a battery pack may be configured by connecting a number of battery cells in parallel depending on the required charge / discharge capacity of the battery pack. Therefore, the number of battery cells included in the battery pack may be variously set depending on the required output voltage or charge / discharge capacity.

[0004] For example, when a battery pack is constructed by connecting a plurality of battery cells in series / parallel, a cell assembly including the plurality of battery cells is first constructed.

[0005] Fig. 1 shows a pack case 20 included in a conventional battery pack in which cell assemblies 10 are housed. As shown in Fig. 1, the pack case 20 provides a space in which the cell assemblies 10 can be housed separately. Each cell assembly 10 is supported at its lower portion by a base plate 30 corresponding to the bottom of the pack case 20, and at its sides by side walls 40 coupled along the edges of the base plate 30. The sides are supported by partition walls 50, and can be separated at the same time.

[0006] 2 shows a pack case 20 in which all the cell assemblies 10 are housed, and each cell assembly 10 is separated by a partition wall 50. Additionally, the pack case 20 may further include a main wall 60 that crosses the center, as shown in FIG. 2, and each cell assembly 10 is seated in an independent space by the main wall 60 and the partition wall 50.

[0007] Meanwhile, the partition wall 50 is generally joined to the base plate 30 by welding.

[0008] 3 is a simplified diagram illustrating the welding of the partition wall 50 and the base plate 30. The corner formed by joining the partition wall 50 and the base plate 30 is welded with a welding torch 70. At this time, a weld bead 80 is generated by the welding, and the weld bead 80 is formed at the corner of the partition wall 50 and the base plate 30 as shown in FIG.

[0009] However, there may be a problem that the weld bead 80 formed by the welding may prevent the cell assembly 10 from being properly seated.

[0010] 4 shows a cross section of the pack case 20 of FIG. 2. Referring to FIG. 4, weld beads 80 are formed on both side edges of the partition wall 50. The weld beads 80 interfere with the corners of the cell assembly 10 when the cell assembly 10 is seated on the base plate 30. That is, the cell assembly 10 may collide with the weld beads 80 during seating, and may not be properly seated on the base plate 30.

[0011] In the past, attempts were made to solve the above-mentioned contact problem by expanding the internal space of the pack case 20. However, this method not only increased the weight of the battery pack, but also created a new problem in that the cell assemblies 10 were not properly supported by the partition walls 50. Summary of the Invention [Problem to be solved by the invention]

[0012] Therefore, the present invention has been devised to solve the above problems, and an object of the present invention is to provide a battery pack in which the sides of the cell assembly are properly supported and the internal space is efficiently utilized.

[0013] Other objects and advantages of the present invention will become apparent from the following description and become more clearly apparent from the embodiments of the present invention. Also, it will be readily apparent that the objects and advantages of the present invention can be realized by the means and combinations thereof as claimed. [Means for solving the problem]

[0014] According to the present invention, there is provided a battery pack including a pack case providing a space in which the cell assemblies are seated, the pack case including a base plate supporting lower portions of the cell assemblies, and a partition wall interposed between a pair of adjacently arranged cell assemblies such that each cell assembly is separated and connected to the base plate, the partition wall being connected to the base plate by a connecting member vertically penetrating a bottom portion of the base plate.

[0015] The partition wall may include a thread groove at a lower end thereof, and the base plate may include a coupling hole formed therethrough at a position corresponding to the thread groove of the partition wall, and the coupling member may be threadedly coupled to the thread groove by passing through the coupling hole.

[0016] The septum may include a plurality of threads.

[0017] The thread grooves may be formed at predetermined intervals along the longitudinal direction of the partition wall.

[0018] The base plate may include a plurality of cooling channels extending along the longitudinal direction of the pack case and spaced apart at predetermined intervals along the width direction of the pack case.

[0019] The coupling member may be inserted between the cooling channels and coupled to the partition wall.

[0020] The connecting member may have a length equal to or greater than the height of the middle of the partition wall.

[0021] The partition wall may further include a reinforcing bar therein, and the connecting member may be inserted into a thread groove of the partition wall to connect with the reinforcing bar.

[0022] The reinforcing bar may be in the form of either a cylinder or a polygonal prism.

[0023] The partition wall may include a plurality of reinforcing bars, each reinforcing bar being spaced apart at a predetermined interval along a height direction of the partition wall. [Effects of the Invention]

[0024] According to the present invention, the efficiency of the internal space of the pack case can be improved.

[0025] In addition, the side of the cell assembly including a plurality of cells can be stably supported, thereby improving the safety of the battery pack.

[0026] Furthermore, even if any one cell assembly expands due to a thermal runaway phenomenon, deformation and explosion of the cell assembly experiencing thermal runaway and other surrounding cell assemblies can be minimized. [Brief explanation of the drawings]

[0027] [Figure 1] 1 shows a pack case included in a conventional battery pack. [Figure 2] 1 shows a conventional pack case containing a cell assembly. [Figure 3] 1 is a simplified diagram showing the welding process of a bulkhead and a base plate included in a conventional pack case. [Figure 4] This shows a cross section of the pack case shown in Figure 2 above. [Figure 5] 1 is a plan view of a pack case included in a battery pack according to a first embodiment of the present invention. [Figure 6] FIG. 6 is a bottom view of the pack case of FIG. 5. [Figure 7] FIG. 6 is a bottom perspective view of the pack case of FIG. 5. [Figure 8] 1 is a cross-sectional view of a portion of a pack case included in a battery pack according to a first embodiment (before coupling of coupling members); [Figure 9] 1 is a cross-sectional view of a portion of a pack case included in a battery pack according to a first embodiment (after coupling of coupling members); [Figure 10] 10 is a cross-sectional view of a portion of a pack case included in a battery pack according to a second embodiment (before coupling of coupling members). [Figure 11] 10 is a cross-sectional view of a portion of a pack case included in a battery pack according to a second embodiment (after coupling of coupling members). [Figure 12] 10 is a cross-sectional view of a pack case included in a battery pack according to a third embodiment (before coupling of coupling members); [Figure 13] 10 is a cross-sectional view of a pack case included in a battery pack according to a third embodiment (after coupling of coupling members). [Figure 14] 1 shows a perspective view of a reinforcing bar inside the bulkhead and a connecting member outside the bulkhead. [Figure 15] 10 is a perspective view of a reinforcing bar inside a partition wall and a connecting member connected to the reinforcing bar. FIG. [Figure 16] 10 is a simplified diagram illustrating a combination of a reinforcing bar and a connecting member of a partition wall included in a battery pack according to a fourth embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0028] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Before that, the terms and words used in the specification and claims should not be interpreted as being limited to their ordinary or dictionary meanings, but should be interpreted as meanings and concepts that are consistent with the technical idea of ​​the present invention based on the principle that the inventor can appropriately define the concepts of the terms to best describe his own invention.

[0029] Therefore, the embodiments described in this specification and the configurations shown in the drawings are merely the most preferred embodiments of the present invention and do not represent the entire technical idea of ​​the present invention, and there may be various equivalents and modifications that can replace them at the time of this application.

[0030] Furthermore, in the description of the present invention, if it is determined that a detailed description of related publicly known structures or functions may obscure the gist of the present invention, the detailed description will be omitted.

[0031] The embodiments of the present invention are provided to more completely explain the present invention to those skilled in the art, and therefore the shapes and sizes of components in the drawings may be exaggerated, omitted, or shown in a schematic manner for clearer explanation. Therefore, the sizes and proportions of each component do not completely reflect the actual sizes and proportions.

[0032] The present invention relates to a battery pack containing a plurality of cell assemblies. More specifically, the battery pack of the present invention is characterized in that a base plate that supports lower ends of the cell assemblies and a partition wall interposed between a pair of adjacently arranged cell assemblies so as to separate the cell assemblies are fixed by screwing together with a connecting member.

[0033] Figures 5 to 9 relate to a battery pack according to a first embodiment of the present invention, Figures 10 to 11 relate to a battery pack according to a second embodiment of the present invention, Figures 12 to 15 relate to a battery pack according to a third embodiment of the present invention, and Figure 16 relates to a battery pack according to a fourth embodiment of the present invention.

[0034] Hereinafter, a battery pack according to each embodiment of the present invention will be described with reference to the drawings.

[0035] (First embodiment) FIG. 5 is a plan view of a pack case 1000 included in a battery pack according to a first embodiment of the present invention, FIG. 6 is a bottom view of the pack case 1000 of FIG. 5, and FIG. 7 is a bottom perspective view of the pack case 1000 of FIG. 5.

[0036] The battery pack of the present invention contains a plurality of cell assemblies S.

[0037] The cell assembly S includes a cell block containing a plurality of cells.

[0038] The cell includes an electrode assembly in which electrodes including anodes and cathodes and separators are alternately stacked, electrode leads electrically connected to the electrodes, and a battery case that encloses and seals the electrode assembly so that the electrode leads can be led out.

[0039] The cells can be classified into cylindrical cells, prismatic cells, and pouch cells depending on the shape of the electrode assembly and the battery case.

[0040] The cylindrical cell has an electrode assembly wound into a roll and inserted into a cylindrical battery case.

[0041] The prismatic cell may be in a stack form in which the electrode assembly is stacked by alternately stacking electrodes and separators, or in a stack-fold form in which electrodes and the like are provided on a sheet-like separator folded at regular intervals.

[0042] In the prismatic cell, the electrode assembly is inserted into a square box-shaped battery case.

[0043] The pouch-type cell may have an electrode assembly in a stacked form or a stack-folded form.

[0044] In the pouch-type cell, the electrode assembly is inserted into a pouch-shaped battery case.

[0045] Therefore, the cell assembly may include any one of cylindrical cells, prismatic cells, and pouch cells.

[0046] The cell assembly S includes a plurality of cells and a bus bar frame including bus bars electrically connected to electrode leads included in each of the cells.

[0047] The cell assembly S may further include a module frame surrounding the periphery of the cell block so that each cell can be protected from external impact. In this case, the module frame may be provided to support or protect only a portion of the cell block, or may be provided on all exposed portions of the cell block to completely isolate the cell block from the outside.

[0048] The battery pack of the present invention includes a pack case 1000 that has a shape capable of enclosing and supporting the sides and bottom of the cell assembly S and directly houses the cell assembly S. The battery pack may also include an upper case that is coupled to the pack case 1000 to cover the upper part of each cell assembly S. However, since the upper case is not closely related to the features of the present invention, a description thereof will be omitted.

[0049] The pack case 1000 provides a space in which the cell assembly S is mounted and serves to protect the mounted cell assembly S from external impacts.

[0050] The pack case 1000 basically includes a base plate 100 , a side wall 200 , and a partition wall 300 .

[0051] The base plate 100 serves to support the lower portion of the cell assembly S, and may have a cooling passage 120 formed therein for cooling the cell assembly S, if necessary.

[0052] The side wall 200 serves to support, enclose and protect the sides of the cell assembly S seated on the base plate 100, and is coupled to the edge of the base plate 100 as shown in FIG.

[0053] As shown in FIG. 5, the partition wall 300 is interposed between a pair of adjacently arranged cell assemblies S so that each cell assembly S is separated, and is coupled to the base plate 100.

[0054] The pack case 1000 may further include a main wall 400 that is connected to the base plate 100 across the center, as shown in FIG.

[0055] The main wall 400 serves to separate the cell assemblies S while dividing the internal space of the pack case 1000 into two large sections.

[0056] The main wall 400 may have conductive wires and bus bars therein.

[0057] The plurality of cell assemblies S housed in the pack case 1000 are seated in the spaces defined by the partition walls 300 and the main walls 400, as shown in FIG.

[0058] In the battery pack of the present invention, a partition wall 300 provided to partition the internal space of the pack case 1000 is screw-coupled to the base plate 100. That is, the partition wall 300 is coupled to the base plate 100 by a coupling member B that vertically penetrates the bottom of the base plate 100.

[0059] The connecting member B may be a bolt capable of being screwed, but the present invention does not limit the specific type thereof.

[0060] 8 and 9 show cross sections of a portion of the pack case 1000 included in the battery pack according to the first embodiment of the present invention. Specifically, Fig. 8 shows the state before the coupling member B is coupled to the partition wall 300, and Fig. 9 shows the state after the coupling member B is coupled to the partition wall 300.

[0061] 7 to 9, the partition wall 300 includes a thread groove 310 at a lower end thereof, and the base plate 100 includes a coupling hole 110 formed therethrough at a position corresponding to the thread groove 310 of the partition wall 300. That is, when the partition wall 300 is primarily coupled to the base plate 100, the thread groove 310 of the partition wall 300 and the coupling hole 110 of the base plate 100 are aligned with each other.

[0062] The coupling member B passes through the coupling hole 110 and is screwed into the thread groove 310 to fix the partition wall 300 to the base plate 100 .

[0063] The partition wall 300 may include a plurality of thread grooves 310 , and the base plate 100 includes a plurality of coupling holes 110 corresponding to the respective thread grooves 310 .

[0064] The plurality of screw grooves 310 may be formed at predetermined intervals along the longitudinal direction of the partition wall 300, and the plurality of coupling members B may be coupled to the partition wall 300 in sequence along the longitudinal direction thereof.

[0065] When the cooling channels 120 are applied to the base plate 100, the cooling channels 120 extend along the longitudinal direction of the pack case 1000 and are spaced apart at predetermined intervals along the width direction of the pack case 1000 as shown in Figures 8 and 9.

[0066] The coupling holes 110 and the thread grooves 310 may be positioned and formed to be interposed between the cooling channels 120, and the coupling member B may be inserted between the cooling channels 120 and coupled to the partition wall 300.

[0067] (Second embodiment) The battery pack according to the second embodiment of the present invention is characterized in that the length of the connecting member B used to fix the partition wall 300 is long.

[0068] 10 and 11 are partial cross-sectional views of a pack case 1000 included in a battery pack according to a second embodiment of the present invention. Specifically, Fig. 10 shows a state before coupling member B to partition wall 300, and Fig. 11 shows a state after coupling member B to partition wall 300.

[0069] The connecting member B is characterized by having a length equal to or greater than the height of the middle of the partition wall 300 .

[0070] When a long connecting member B is used as described above, it is inserted to a height equal to or greater than the middle height of the partition wall 300, thereby improving the mechanical strength of the partition wall 300. That is, the connecting member B improves the resistance of the partition wall 300 to an external force acting in the horizontal direction. For example, if a problem occurs in the housed cell assembly S and it expands, the partition wall 300 and the connecting member B inserted into the partition wall 300 can fully withstand the expansion force transmitted from the cell assembly S.

[0071] (Third embodiment) The battery pack according to the third embodiment of the present invention further includes a reinforcing bar 320 inside the partition 300, and the connecting member B is connected to the reinforcing bar 320, thereby improving the mechanical strength of the partition 300. That is, the battery pack according to the third embodiment is characterized in that the reinforcing bar 320 is further added to the connecting member B of the battery pack according to the second embodiment.

[0072] The reinforcing bar 320 may be, but is not limited to, steel, and may include any material that has high mechanical strength and is relatively light in weight.

[0073] 12 and 13 show cross sections of a pack case 1000 included in a battery pack according to the third embodiment. Specifically, Fig. 12 shows a reinforcing bar 320 inside a partition wall 300 and a connecting member B connected to the reinforcing bar 320, and Fig. 13 shows the reinforcing bar 320 of Fig. 12 connected to the connecting member B.

[0074] As shown in FIGS. 12 and 13, the partition wall 300 further includes a reinforcing bar 320 therein, and the connecting member B is inserted into the thread groove 310 of the partition wall 300 to be connected to the reinforcing bar 320.

[0075] The reinforcing bar 320 is provided inside the partition wall 300 and extends along the longitudinal direction of the partition wall 300. Therefore, when an external force acts on one side of the partition wall 300, the external force can be dispersed through the reinforcing bar 320. In addition, the partition wall 300 can more effectively resist an external force acting in a horizontal direction through the connecting member B connected to the reinforcing bar 320.

[0076] FIG. 14 shows a perspective view of the reinforcing bar 320 inside the partition wall 300 and the connecting member B outside the partition wall 300, and FIG. 15 shows a perspective view of the reinforcing bar 320 inside the partition wall 300 and the connecting member B connected to the reinforcing bar 320.

[0077] The reinforcing bar 320 includes a plurality of reinforcing holes 321 formed therethrough at positions corresponding to the thread grooves 310. Therefore, the coupling member B inserted into the thread grooves 310 can be coupled to the reinforcing bar 320 while passing through the reinforcing holes 321 of the reinforcing bar 320.

[0078] The reinforcing bar 320 may be cylindrical as shown in FIGS. 14 and 15, but is not limited thereto and may also be a polygonal pillar.

[0079] (Fourth embodiment) The battery pack according to the fourth embodiment of the present invention is characterized in that a plurality of reinforcing bars 320 included in the battery pack according to the third embodiment are used.

[0080] FIG. 16 is a simplified diagram illustrating the connection between a reinforcing bar 320 of a partition wall 300 and a connecting member B included in a battery pack according to a fourth embodiment of the present invention.

[0081] As shown in FIG. 16, the partition wall 300 includes a plurality of reinforcing bars 320, and the reinforcing bars 320 are spaced apart from each other at predetermined intervals along the height direction of the partition wall 300.

[0082] At this time, the reinforcing bars 320 are positioned such that the connecting member B inserted into the partition wall 300 penetrates all the reinforcing bars 320 .

[0083] The present invention has been described in more detail above through the drawings and embodiments, etc. However, the configurations described in the drawings or embodiments in this specification are merely one embodiment of the present invention and do not represent all of the technical ideas of the present invention, and therefore, there may be various equivalents and modifications that can replace them at the time of filing this application. [Explanation of symbols]

[0084] 10: (Prior Art) Cell Assembly 20: (Conventional technology) Pack case 30: (Prior Art) Base Plate 40: (Prior Art) Sidewall 50: (Conventional) Partition 60: (Conventional technology) Main wall 70: (Prior Art) Welding Torch 80: (Conventional technology) Weld bead 1000: Pack case 100: Base plate 110: Connection hole 120: Cooling channel 200: Side wall 300: Bulkhead 310: Thread groove 320: Reinforcement bar 321: Reinforcement hole 400: Main wall S: Cell assembly B: Connecting member

Claims

1. In a battery pack containing a plurality of cell assemblies, a pack case that provides a space in which the cell assembly is seated, The pack case is a base plate supporting a lower portion of the cell assembly; a partition wall interposed between a pair of adjacently arranged cell assemblies such that each cell assembly is separated and coupled to the base plate; The partition wall is connected to the base plate by a connecting member that vertically penetrates a bottom of the base plate.

2. the partition wall includes a thread groove at a lower end thereof; 2. The battery pack of claim 1, wherein the base plate includes a coupling hole formed therethrough at a position corresponding to the thread groove of the partition wall, and the coupling member is threadedly coupled to the thread groove by passing through the coupling hole.

3. The battery pack according to claim 2 , wherein the partition wall includes a plurality of thread grooves.

4. The battery pack according to claim 3 , wherein the thread grooves are formed at predetermined intervals along a longitudinal direction of the partition wall.

5. The battery pack according to claim 1 , wherein the base plate includes a plurality of cooling channels extending along a longitudinal direction of the pack case and spaced apart at predetermined intervals along a width direction of the pack case.

6. The battery pack according to claim 5 , wherein the connecting member is inserted between the cooling channels and connected to the partition wall.

7. The battery pack according to claim 1 , wherein the connecting member has a length equal to or greater than the height of the middle section of the partition wall.

8. the bulkhead further includes a reinforcing bar therein; The battery pack according to claim 1 , wherein the connecting member is inserted into a thread groove of the partition wall to be connected to the reinforcing bar.

9. The battery pack of claim 8 , wherein the reinforcing bar has one of a cylindrical shape and a polygonal shape.

10. the bulkhead includes a plurality of reinforcing bars; The battery pack according to claim 8 , wherein the reinforcing bars are spaced apart at predetermined intervals along a height direction of the partition wall.

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