Battery pack with improved cooling performance and automobile including same

Abstract

A battery pack according to one embodiment of the present invention includes a pack case having a coolant inlet and a coolant outlet through which an insulating coolant flows in and flows out, a cross beam disposed inside the pack case and forming a space through which the insulating coolant can pass, and a plurality of battery modules including a plurality of battery cells and each disposed in a space partitioned by the cross beam.

Description

[Technical field]

[0001] The present invention relates to a battery pack and a vehicle including the same, and more particularly to a battery pack capable of effectively improving the cooling efficiency of a battery cell, and a vehicle including the same.

[0002] This application claims priority to Korean Patent Application No. 10-2021-0058807, filed on May 6, 2021, the entire contents of which are incorporated herein by reference in their entirety in the specification and drawings. [Background technology]

[0003] Recently, with the development of mobile devices, rechargeable secondary batteries have been widely used. In addition, secondary batteries have been attracting attention as a power source for electric vehicles, which have been presented as a solution to air pollution caused by existing gasoline-powered and diesel-powered vehicles that use fossil fuels.

[0004] Meanwhile, in the case of devices that require a large amount of electricity, such as electric vehicles, a battery pack must usually include many battery modules, and in order to increase the energy density, multiple battery modules are often configured in a densely packed form in an extremely small space.

[0005] However, a large amount of heat is generated during the charging and discharging process of such high-capacity secondary batteries. If the heat generated during the charging and discharging process is not effectively removed, heat accumulation will occur, which will result in accelerated battery deterioration and, in some cases, may pose a risk of fire or explosion.

[0006] Therefore, for vehicle battery packs, which are high-capacity batteries, there is a demand for the development of a cooling system that can efficiently cool the battery cells contained therein. Summary of the Invention [Problem to be solved by the invention]

[0007] The present invention has been devised to solve the above problems, and aims to provide a battery pack and an automobile including the same that improve the cooling efficiency of the battery cells by adopting a method of directly cooling the battery cells with an insulating coolant.

[0008] Another object of the present invention is to reduce the manufacturing cost of the battery pack and to achieve a smaller battery pack.

[0009] However, the technical problems that the present invention aims to solve are not limited to the problems described above, and other problems not mentioned will be clearly understood by those skilled in the art from the description of the invention described below. [Means for solving the problem]

[0010] To achieve the above object, a battery pack according to the present invention includes a pack case having a coolant inlet and a coolant outlet through which an insulating coolant flows in and out, a cross beam disposed inside the pack case to form a space through which the insulating coolant can pass, and a plurality of battery modules including a plurality of battery cells, each disposed in a space partitioned by the cross beam.

[0011] Meanwhile, the pack case may be sealed except for the coolant inlet and the coolant outlet.

[0012] Here, the multiple battery cells contained within the battery module are in direct contact with the insulating coolant liquid.

[0013] In particular, the insulating coolant may be introduced into an inlet located on one side of the battery module, and may be discharged across the battery module to an outlet located on the opposite side of the inlet.

[0014] Meanwhile, the battery module may include a plurality of corner regions, and the inlet and the outlet of the battery module may be located in any one of the plurality of corner regions.

[0015] In addition, the insulating coolant flowing out from the outlet of a particular battery module may flow into the inlet of an adjacent battery module.

[0016] Meanwhile, the insulating coolant flowing into the coolant inlet of the pack case may sequentially pass through all battery modules included in the battery pack and then flow out to the coolant outlet.

[0017] Meanwhile, the battery cells included in the battery module may be arranged at regular intervals from each other.

[0018] Alternatively, the arrangement density of the plurality of battery cells included in the battery module may gradually increase or decrease in a particular direction.

[0019] In particular, the battery cells included in the battery module may have an arrangement density that is lower in an area farther away from a shortest path from the inlet to the outlet.

[0020] On the other hand, the cross beam may be spaced a predetermined distance from the side cover of the pack case.

[0021] Alternatively, the cross beam may be in contact with a side cover of the pack case, and an opening through which the insulating cooling liquid can flow in and out may be formed in at least a part of the cross beam.

[0022] An automobile according to an embodiment of the present invention includes a battery pack according to an embodiment of the present invention. Effect of the Invention

[0023] According to the present invention, the direct contact between the insulating coolant and each battery cell and the specific arrangement of the cross beams and / or battery cells inside the battery pack enable efficient cooling of the battery pack.

[0024] Furthermore, the present invention allows the battery pack to be made smaller, thereby reducing manufacturing costs.

[0025] The following drawings attached to this specification illustrate preferred embodiments of the present invention and, together with the detailed description of the invention, serve to further understand the technical ideas of the present invention. Therefore, the present invention should not be interpreted as being limited only to the matters described in the drawings. [Brief description of the drawings]

[0026] [Figure 1] 1 is a perspective view of a battery pack according to an embodiment of the present invention; FIG. [Diagram 2] FIG. 2 is a plan view of a battery pack according to an embodiment of the present invention. [Diagram 3] FIG. 13 is a plan view of a battery pack according to another embodiment of the present invention. [Figure 4a] FIG. 4a is a perspective view of a battery pack according to still another embodiment of the present invention. [Figure 4b] FIG. 4b is a cross-sectional view taken along line AA' in FIG. 4a, viewed from a direction perpendicular to the cut surface. [Figure 4c] FIG. 4c is a cross-sectional view showing an embodiment different from that of FIG. 4b. [Diagram 5] FIG. 3 is an enlarged plan view of the dotted line portion in FIG. 2. [Figure 6] FIG. 6 is a plan view showing an embodiment different from that of FIG. 5. [Figure 7] FIG. 1 is a perspective view showing an automobile including a battery pack of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0027] Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings. Prior to this, 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 having meanings and concepts that correspond to the technical ideas of the present invention, in accordance with the principle that the inventor himself can appropriately define the concepts of terms in order to best describe the invention.

[0028] Therefore, it should be understood that the embodiment described in this specification and the configurations shown in the drawings are merely the most preferred embodiment of the present invention and do not represent the entire technical idea of ​​the present invention, and that there may be various equivalents and modifications that can be substituted therefor at the time of this application.

[0029] FIG. 1 is a perspective view of a battery pack according to one embodiment of the present invention, and FIG. 2 is a plan view of the battery pack according to one embodiment of the present invention.

[0030] 1 and 2, a battery pack 1 according to the present invention includes a pack case 10, a cross beam 20, and a battery module 30. Such a battery pack 1 may be used in, for example, an electric vehicle 2.

[0031] First, the pack case 10 will be described.

[0032] Referring to Fig. 1, the pack case 10 includes a lower cover 11, an upper cover 12, and a side cover 13. The pack case 10 includes a coolant inlet part P1 and a coolant outlet part P2 that function as paths through which an insulating coolant flows in and flows out. The pack case 10 accommodates a cross beam 20 and a battery module 30 therein. The pack case 10 can protect the battery modules 30 from external impacts, and therefore, the material of the pack case 10 is preferably, but is not limited to, hard. For convenience of describing the internal structure of the pack case 10, the pack case 10 is shown by dotted lines.

[0033] The cooling liquid inlet P1 and the cooling liquid outlet P2 may be formed in the side cover 13, so that the insulating cooling liquid may flow in and out. Alternatively, the cooling liquid inlet P1 and the cooling liquid outlet P2 may be formed in the lower cover 11 or the upper cover 12. The pack case 10 may be sealed except for the cooling liquid inlet P1 and the cooling liquid outlet P2 because the insulating cooling liquid passes through the inside of the pack case 10. Therefore, the insulating cooling liquid flowing into the cooling liquid inlet P1 does not leak out to the outside of the pack case 10. Meanwhile, the insulating cooling liquid flowing into the cooling liquid inlet P1 of the pack case 10 may flow out to the cooling liquid outlet P2 after passing through all the battery modules 30 included in the battery pack 1 in sequence.

[0034] As a result, the insulating coolant cools all the battery cells 31 included in the battery pack 1 through direct contact therewith, thereby improving the cooling efficiency.

[0035] Meanwhile, the cooling liquid may be a liquid with high insulating performance, such as insulating cooling oil, but is not limited thereto.

[0036] Next, the cross beam 20 will be described.

[0037] FIG. 2 is a plan view of a battery pack according to one embodiment of the present invention, FIG. 3 is a plan view of a battery pack according to another embodiment of the present invention, and FIG. 4 is a perspective view and a cross-sectional view of a battery pack according to still another embodiment of the present invention.

[0038] 2 to 4, the cross beam 20 may include at least one horizontal beam 21 and at least one vertical beam 22. The horizontal beam 21 and the vertical beam 22 may intersect approximately perpendicularly to each other. Specifically, FIG. 2 shows a cross-shaped cross beam 20 in which one horizontal beam 21 and one vertical beam 22 intersect each other, and FIG. 3 shows a cross beam 20 in which two horizontal beams 211, 212 and one vertical beam 22 intersect each other.

[0039] As shown in FIG. 2, when the cross beam 20 has a shape in which one horizontal beam 21 and one vertical beam 22 cross each other substantially perpendicularly, the internal space of the pack case 10 is partitioned into four spaces.

[0040] Alternatively, as shown in Fig. 3, when the cross beam 20 has a shape in which two horizontal beams 211, 212 and one vertical beam 22 cross each other substantially perpendicularly, the internal space of the pack case 10 may be partitioned into six spaces. In this manner, the internal space of the pack case 10 may be partitioned into a plurality of spaces by at least one horizontal beam 21 and one vertical beam 22, and a battery module 30 may be disposed in each of the partitioned spaces. For reference, although not shown, a plurality of vertical beams 22 may be formed.

[0041] In the drawings of the present invention, the pack case 10 is shown only in the case where its internal space is divided into four (see FIG. 2) and six (see FIG. 3), but the present invention is not limited thereto. The cross beam 20 may include three or more horizontal beams, or may include two or more vertical beams. In this case, the internal space of the pack case 10 may be divided into eight or more spaces.

[0042] Meanwhile, a coolant passage through which the insulation coolant can pass from the accommodation space of one battery module to the accommodation space of another adjacent battery module may be formed in the pack case 10 by a structure in which the cross beam 20 is spaced a predetermined distance from the side cover 13 of the pack case 10, or by a structure in which an opening is formed in the cross beam 20. That is, the cross beam 20 may be provided to form a space through which the insulation coolant can pass.

[0043] First, a structure in which the cross beam 20 is spaced a predetermined distance from the side cover 13 of the pack case 10 will be described. Referring to Fig. 2, both ends of the horizontal beam 21 in the longitudinal direction (direction aligned with the X-axis) are spaced a predetermined distance from the side cover 13 of the pack case 10. One end of the vertical beam 22 in the longitudinal direction (direction aligned with the Y-axis) is spaced a predetermined distance from the side cover 13 of the pack case 10. This allows the insulating coolant to pass through the gap G formed between the cross beam 20 and the side cover 13. The arrows shown in Fig. 2 indicate a general flow of the insulating coolant.

[0044] In this manner, by forming the gap G between the cross beam 20 and the side cover 13 of the pack case 10, the application of a simple structure such as the cross beam 20 alone can efficiently guide the flow of the insulating coolant in the battery pack 1. In addition, according to the above structure, the application of a simple structure such as the cross beam 20 alone can allow the insulating coolant to pass through the entire area of ​​the battery pack 1, thereby improving the cooling efficiency.

[0045] Next, a structure in which an opening is formed in the cross beam 20 will be described. Fig. 4a is a perspective view of a battery pack according to another embodiment of the present invention, Fig. 4b is a cross-sectional view of a cut surface taken along A-A' in Fig. 4a, viewed from a direction perpendicular to the cut surface, and Fig. 4c is a cross-sectional view showing an embodiment different from Fig. 4b.

[0046] 4a to 4c, the cross beam 20 abuts against the side cover 13 of the pack case 10 with no gap.

[0047] Referring to Fig. 4b, an opening through which the insulating cooling liquid can flow in and out is formed in at least a portion of the cross beam 20. The shape of the opening may be a notch-like shape H1. Referring to Fig. 4c, which is another embodiment, the opening may be a hole-like shape H2. However, the shape of the opening is not limited thereto, and may be any shape through which the insulating cooling liquid can flow in and out.

[0048] According to this embodiment, the cross beam 20 abuts against the side cover 13 of the pack case 10 without any gaps, so that the battery pack 1 is adequately supported by the cross beam 20, thereby effectively protecting the battery cells 31 inside the battery pack 1 even in the event of an external impact such as a car accident.

[0049] Meanwhile, the embodiments of the present invention are not limited to the structure in which the cross beam 20 is spaced a predetermined distance from the side cover 13 of the pack case 10 (see FIG. 2) or the structure in which an opening is formed in the cross beam 20 (see FIGS. 4a to 4c), and each embodiment may be applied in combination. For example, the horizontal beam may be applied with a structure in which the cross beam 20 is spaced a predetermined distance from the side cover 13 of the pack case 10, and the vertical beam may be applied with a structure in which an opening is formed in the cross beam 20, or vice versa.

[0050] Next, the battery module 30 will be described.

[0051] FIG. 5 is an enlarged plan view of the dotted line portion of FIG. 2, and FIG. 6 is a plan view showing an embodiment different from that of FIG.

[0052] Here, the battery module 30 is defined as an assembly of a plurality of battery cells 31, and the battery module 30 does not necessarily have to include a physical battery module case. However, it goes without saying that the battery module 30 may include a battery module case in other embodiments of the present invention.

[0053] 1, 2, 5 and 6, a battery module 30 according to the present invention includes a plurality of battery cells 31.

[0054] In Fig. 2, the portion indicated by the dotted line (dash-dotted line) corresponds to one battery module 30. Referring to Fig. 6, the battery module 30 may have a plurality of corner regions 301, 302, 303, and 304. Fig. 6 shows a case where the overall shape of the battery module 30 is substantially rectangular when viewed based on a plan view, and thus shows only a case where the battery module 30 has four corner regions 301, 302, 303, and 304. However, the battery module 30 of the present invention is not limited to such a shape.

[0055] 1, a battery module 30 according to an embodiment of the present invention may not include a physical battery module case. In one embodiment of the present invention, the battery module 30 is an assembly of a plurality of battery cells 31, and more specifically, refers to an assembly of battery cells 31 located in an internal space of a pack case 10 partitioned by a cross beam 20.

[0056] The battery module 30 includes an inlet and an outlet through which the insulating coolant flowing into the pack case 10 flows in and out. The inlet and outlet may refer to, for example, a pipe and / or a hole functioning as a passage for the insulating coolant, but may also be merely names introduced for the convenience of describing the flow of the insulating coolant in the battery module 30.

[0057] When the battery module 30 includes a separate module case (not shown) that houses a plurality of battery cells 31, a substantial passage for the inflow and outflow of the insulating coolant must be present in the module case in order for the insulating coolant to directly contact the battery cells 31. Therefore, in this case, the inlet and outlet may refer to physical elements such as pipes and / or holes that function as a passage.

[0058] On the other hand, if the battery module 30 does not include a separate module case, and thus the multiple battery cells 31 are disposed on the lower cover 11 of the pack case 10, the inlet and outlet may refer to an area into which the insulating coolant flows and an area into which the insulating coolant flows, rather than to physical elements that actually exist. Of course, even if the battery module 30 does not include a module case, physical elements such as guide plates or pipes for smoothly guiding the flow of the insulating coolant may be applied to the inlet and outlet areas of the insulating coolant of the battery module 30. Therefore, in this case, even if there is no module case, the inlet and outlet may refer to physical elements.

[0059] 2 to 4c, the spaces partitioned by the cross beam 20 are interconnected by a gap G formed by the distance between the cross beam 20 and the side cover 13, or by an opening having a shape such as a notch or a hole formed in the cross beam 20. That is, the outlet of the battery module 30 located on one side and the inlet of the battery module 30 located on the other side across the horizontal beam 21 or vertical beam 22 are formed in the cross beam 20 itself, or are provided at positions corresponding to the coolant passages formed between the cross beam 20 and the side cover 13.

[0060] Meanwhile, the inlet and the outlet of the battery module 30 may each be located in one of a plurality of corner regions 301, 302, 303, and 304. For example, referring to the battery module 30 of Fig. 5, the inlet may be located in the lower left corner region 301 and the outlet may be located in the upper right corner region 302, and the insulating coolant flowing into the inlet may pass through the battery module 30 and flow out to the outlet.

[0061] Meanwhile, the battery module 30 according to an embodiment of the present invention may have a structure in which the insulation coolant flowing into an inlet located on one side of the battery module 30 flows out to an outlet located on the opposite side of the inlet across the battery module 30. For example, the insulation coolant may flow into an inlet located in a lower left corner region 301 of Fig. 5 and flow out to an outlet on the opposite side of the inlet across the battery module 30, i.e., an outlet located in a corner region 302.

[0062] 2 and 3, the insulation coolant flowing out from the outlet of a particular battery module 30 may flow into the inlet of an adjacent battery module 30. In particular, the insulation coolant flowing into the coolant inlet part P1 of the pack case 10 may pass through all the battery modules 30 included in the battery pack 1 in sequence, and then flow out to the coolant outlet part P2.

[0063] The flow of the insulating coolant will be described with reference to FIG. 2. The insulating coolant flowing into the first battery module 30A from the coolant inlet P1 moves from the inlet to the outlet of the first battery module 30A and flows into the second battery module 30B through the coolant passage. The insulating coolant flowing into the inlet of the second battery module 30B flows into the third battery module 30C through the outlet and coolant passage of the second battery module 30B. The insulating coolant flowing into the inlet of the third battery module 30C flows into the fourth battery module 30D through the outlet and coolant passage of the third battery module 30C. The insulating coolant flowing into the inlet of the fourth battery module 30D is discharged to the outside of the battery pack 1 through the outlet and coolant outlet P2 of the fourth battery module 30D.

[0064] As a result, the insulating coolant flows out after cooling all the battery modules 30, so that the insulating coolant comes into direct contact with all the battery cells 31, thereby maximizing the cooling efficiency.

[0065] Meanwhile, in the embodiment shown in FIG. 1 and the like, the battery cell 31 is shown as a cylindrical cell, but is not limited thereto, and may be a prismatic cell or a pouch-type cell.

[0066] Meanwhile, a plurality of battery cells 31 are disposed within a space partitioned by the cross beam 20. All the battery cells 31 included in the battery module 30 may be in direct contact with the insulating coolant.

[0067] This maximizes the contact area between the insulating coolant and each battery cell 31, thereby improving the overall cooling efficiency of the battery pack 1. In addition, the structure of the present invention in which the battery cells 31 are in direct contact with the insulating coolant does not require a heat sink that occupies a separate space as a component, thereby reducing the manufacturing cost of the battery pack 1 and further reducing the size of the battery pack 1. In addition, the structure of the present invention in which the lower surface, the outer peripheral surface of the side, and even the upper surface in some cases of the battery cells 31 are in direct contact with the insulating coolant increases the cooling area, thereby maximizing the cooling efficiency of the battery pack 1.

[0068] 5, a plurality of battery cells 31 included in a battery module 30 according to an embodiment of the present invention may be arranged at regular intervals from one another, for example, in a checkerboard arrangement.

[0069] According to this embodiment, since the battery cells 31 are arranged at regular intervals, the structure is simple and the convenience of manufacturing the battery pack 1 is increased.

[0070] 6, in another embodiment of the present invention, the arrangement density of the plurality of battery cells 31 included in the battery module 30 may be arranged to gradually increase or decrease in a specific direction. That is, the arrangement shape of the plurality of battery cells 31 may be in a gradation shape.

[0071] 6, the arrangement density of the battery cells 31 included in the battery module 30 may be formed to be lower in an area farther from the shortest route S among the routes from the inlet to the outlet. More specifically, the battery cells 31 are arranged at a relatively high density in the shortest route S from the inlet to the outlet to make it more difficult for the insulation cooling liquid to flow compared to other routes, and the battery cells 31 are arranged at a relatively low density in an area farther from the shortest route S to prevent the insulation cooling liquid from concentrating and flowing on the shortest route S. In particular, among the corner regions 301, 302, 303, and 304 of the battery module 30, there may be a problem that it is difficult for the insulating coolant to flow into the corner regions 303 and 304 where no inlets and outlets are located due to the physical structure. However, in the present invention, the arrangement density of the battery cells 31 in the corner regions 303 and 304 is made the lowest as shown in FIG. 6, so that the insulating coolant can smoothly flow into the corner regions 303 and 304 where no inlets and outlets are located.

[0072] With this structure, the present invention can effectively cool even the battery cells 31 located near the corner regions 303, 304 where the inlets and outlets are not located, thereby improving the cooling efficiency of the battery module 30 uniformly overall.

[0073] FIG. 7 is a perspective view showing an automobile 2 including a battery pack 1 of the present invention.

[0074] Referring to FIG. 7, a vehicle 2 according to the present invention may include a battery pack 1 according to the present invention.

[0075] In this specification, terms indicating directions such as up and down are used, but such terms are used merely for the convenience of explanation, and it will be obvious to those skilled in the art that such terms may change depending on the position of the object of interest, the position of the observer, etc.

[0076] Although the present invention has been described above using limited embodiments and drawings, the present invention is not limited thereto, and it goes without saying that various modifications and variations can be made by a person having ordinary knowledge in the technical field to which the present invention pertains within the scope of the technical concept of the present invention and the scope of the claims. [Explanation of symbols]

[0077] 1 Battery Pack 10 pack case 20 Cross Beam 30 Battery Module 31 Battery Cells P1 Coolant inlet P2 Coolant outflow part

Claims

1. a pack case having a cooling liquid inlet and a cooling liquid outlet through which an insulating cooling liquid flows in and flows out; a cross beam disposed inside the pack case such that a space through which the insulating and cooling liquid can pass is formed; A plurality of battery modules each including a plurality of battery cells and each being disposed within a space defined by the cross beam; Including, a battery pack in which an arrangement density of the battery cells included in the battery module is formed to be lower in an area farther away from a shortest path of the insulating cooling liquid path from the cooling liquid inlet side to the cooling liquid outlet side.

2. The battery pack according to claim 1 , wherein the pack case is sealed except for the coolant inlet and the coolant outlet.

3. 2. The battery pack according to claim 1, wherein a plurality of battery cells contained within the battery module are in direct contact with the insulating coolant fluid.

4. 2. The battery pack of claim 1, wherein the insulating coolant flows into an inlet located on one side of the battery module and flows out of the insulating coolant to an outlet located on an opposite side of the inlet across the battery module.

5. the battery module includes a plurality of corner regions; The battery pack according to claim 4 , wherein the inlet and the outlet of the battery module are each located in one of the plurality of corner regions.

6. The battery pack according to claim 4 , wherein the insulating coolant flowing out of the outlet of a particular battery module flows into the inlet of an adjacent battery module.

7. 5. The battery pack of claim 4, wherein the insulating coolant flowing into the coolant inlet of the pack case passes through all battery modules included in the battery pack in sequence before flowing out to the coolant outlet.

8. The battery pack according to claim 1 , wherein the battery cells included in the battery module are arranged at regular intervals from each other.

9. The battery pack of claim 1 , wherein an arrangement density of the battery cells included in the battery module gradually increases or decreases in a particular direction.

10. 5. The battery pack according to claim 4, wherein an arrangement density of the battery cells included in the battery module is formed to be lower in an area farther away from a shortest path in a path from the inlet to the outlet.

11. The battery pack according to claim 1 , wherein the cross beam is spaced apart from the side cover of the pack case by a predetermined distance.

12. the cross beam is in contact with a side cover of the pack case, The battery pack according to claim 1 , wherein an opening through which the insulating cooling liquid can flow in and out is formed in at least a portion of the cross beam.

13. A motor vehicle comprising a battery pack according to any one of claims 1 to 12.

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