Battery pack with improved cooling performance and device including same

Abstract

The present invention relates to a battery pack with improved cooling performance and a device including the same, and more particularly to a battery pack including a pack case (100) having a predetermined space, a plurality of battery modules (200) housed inside the pack case (100), a bus bar (400) electrically connecting the plurality of battery modules (200), and a cooling member (500) provided at a lower part of the pack case (100), wherein a predetermined area of ​​the bus bar (400) is located on the cooling member (500), and a device including the battery pack.

Description

[Technical field]

[0001] This application claims the benefit of priority based on Korean Patent Application No. 2020-0133171 filed on October 15, 2020, and all contents disclosed in the documents of that Korean patent application are incorporated herein by reference.

[0002] The present invention relates to a battery pack with improved cooling performance and a device including the same, and more particularly to a battery pack with improved cooling performance that can stably maintain the temperature of the battery pack by forming a bus bar and a cooling member integrally, thereby directly cooling the bus bar together with the battery module. [Background technology]

[0003] Recently, the demand for secondary batteries that can store electrical energy produced by the development of alternative energy sources due to air pollution caused by the use of fossil fuels and energy depletion is increasing. Rechargeable secondary batteries are used in mobile devices, electric vehicles, hybrid electric vehicles, etc., and are closely related to daily life.

[0004] Secondary batteries are used as energy sources for various electronic devices that are essential in modern society, and the required capacity is increasing due to the increased use and complication of mobile devices and the development of electric vehicles, etc. To meet user demand, many battery cells are arranged in small devices, while automobiles use battery modules that electrically connect many battery cells or battery packs equipped with many such battery modules.

[0005] Meanwhile, although secondary batteries have excellent electrical characteristics, as devices require increased output, the amount of current flowing therethrough increases, and the temperature of the secondary batteries may rise rapidly.

[0006] In addition, abnormal operation such as overcharging, over-discharging, and overcurrent can cause decomposition reactions of the active materials and electrolytes that are components of the battery, generating heat and gas, which causes the secondary battery to expand, resulting in a so-called swelling phenomenon. The swelling phenomenon can accelerate the decomposition reactions and cause the secondary battery to ignite or explode due to thermal runaway.

[0007] FIG. 1 is a perspective view showing a battery module according to the prior art. As shown in FIG. 1, the battery module according to the prior art contains a plurality of battery cells 10. adjacent The battery pack includes bus bars 20 that electrically connect the plurality of battery cells 10 arranged in a row, a flat bus bar housing 30 attached to the lower surfaces of the plurality of bus bars 20, and a cooling water circulation pipe 40 attached to the upper surface of the bus bar housing 30.

[0008] As described above, the battery module according to the conventional technology has the coolant circulation pipe 40 on the upper surface of the bus bar housing 30 connected to the plurality of bus bars 20, and therefore the heat generated inside is cooled by the coolant circulation pipe 40 after passing through the bus bars 20, which has the advantage that the bus bars 20 can also be cooled together.

[0009] However, the battery module according to the conventional technology has a structure in which the cooling water circulation pipe 40 is simply disposed on the upper part of the bus bar 20, which not only results in low cooling efficiency but also causes problems in that the overall volume of the battery module is increased by the cooling water circulation pipe 40. [Prior art documents] [Patent documents]

[0010] [Patent Document 1] Korean Patent Publication No. 2019-0140669 Summary of the Invention [Problem to be solved by the invention]

[0011] In order to solve the above problems, an object of the present invention is to provide a battery pack and a device including the same, which can minimize an increase in volume while simultaneously cooling heat generated in battery modules and bus bars connecting the battery modules.

[0012] Another object of the present invention is to provide a battery pack and a device including the same, in which the cooling member and the bus bar are integrally combined, thereby enabling simplification of the manufacturing process.

[0013] It is yet another object of the present invention to provide a battery pack and a device including the same, in which the busbar can be cooled quickly and the surface area of ​​the busbar can be reduced. [Means for solving the problem]

[0014] In order to achieve the above object, the battery pack according to the present invention includes a pack case (100) having a predetermined space, a plurality of battery modules (200) housed inside the pack case (100), a bus bar (400) electrically connecting the plurality of battery modules (200), and a cooling member (500) provided at a lower part of the pack case (100), and a predetermined area of ​​the bus bar (400) is located in the cooling member (500).

[0015] In addition, in the battery pack according to the present invention, the pack case (100) includes an upper pack case (110) and a lower pack case (120), and the lower pack case (120) is formed with a first slit (121) through which the bus bar (400) passes.

[0016] In the battery pack according to the present invention, the cooling member (500) includes a body portion (510) and a cooling pipe (520).

[0017] In the battery pack according to the present invention, the body portion (510) is formed with a second slit (511) through which the bus bar (400) passes.

[0018] In the battery pack according to the present invention, the cooling pipe (520) is embedded in the body part (510).

[0019] In addition, in the battery pack according to the present invention, the bus bar (400) includes a horizontal portion (410) and vertical portions (420) extending vertically from both ends of the horizontal portion (410) to a predetermined length.

[0020] In the battery pack according to the present invention, predetermined portions of the horizontal portion (410) and the vertical portion (420) of the bus bar (400) are embedded in the body portion (510).

[0021] In the battery pack according to the present invention, the cooling pipe (520) is located relatively lower than the horizontal portion (410) and the vertical portion (420) of the embedded bus bar (400).

[0022] In the battery pack according to the present invention, the bus bar (400) and the cooling pipe (520) are integrally formed with the body part (510) by insert injection molding.

[0023] The present invention may also be a device including the battery pack. Effect of the Invention

[0024] As described above, the battery pack with improved cooling performance and the device including the battery pack according to the present invention have an advantage that the bus bar can be directly cooled via the cooling member, thereby quickly removing heat from the bus bar.

[0025] In addition, in the battery pack with improved cooling performance and the device including the same according to the present invention, the bus bar and the cooling member are integrally formed by insert injection molding, which has the advantage that a connecting member for connecting the bus bar and the cooling member can be omitted, thereby reducing manufacturing costs.

[0026] Furthermore, in the battery pack with improved cooling performance and the device including the same according to the present invention, the bus bar is embedded in the cooling member, so that an increase in volume can be minimized, resulting in an advantage of high energy density. [Brief description of the drawings]

[0027] [Figure 1] FIG. 1 is a perspective view showing a battery module according to the prior art. [Diagram 2] 1 is a perspective view of a battery pack according to a preferred embodiment of the present invention; [Diagram 3] FIG. 3 is an exploded perspective view of the battery pack shown in FIG. 2. [Figure 4] FIG. 2 is an exploded perspective view illustrating a connection structure between a bus bar and a cooling member according to the present invention. [Diagram 5] FIG. 4 is a cross-sectional view taken along line AA' in FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0028] Hereinafter, the present invention will be described in detail with reference to the accompanying drawings, in which a person having ordinary skill in the art to which the present invention pertains can easily carry out the present invention. However, in describing the operation principle of the preferred embodiment of the present invention in detail, detailed description of related well-known functions or configurations will be omitted if it is determined that such detailed description may unnecessarily obscure the gist of the present invention.

[0029] In addition, the same reference numerals are used throughout the drawings for parts having similar functions and actions. Throughout the specification, when a part is said to be connected to another part, this includes not only the case where the part is directly connected to another part, but also the case where the part is indirectly connected via another element between the two parts. In addition, when a part includes a certain component, it does not mean that the other component is excluded, but that the part may further include the other component, unless otherwise specified.

[0030] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A battery pack with improved cooling performance according to the present invention will now be described with reference to the accompanying drawings.

[0031] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A battery pack with improved cooling performance according to the present invention will now be described with reference to the accompanying drawings.

[0032] FIG. 2 is a perspective view of a battery pack according to a preferred embodiment of the present invention, and FIG. 3 is an exploded perspective view of the battery pack shown in FIG.

[0033] As shown in FIGS. 2 and 3, the battery pack according to the present invention includes a pack case 100, a plurality of battery modules 200 housed in the pack case 100, a BDU (Battery Disconnect Unit) 300, a bus bar 400 electrically connecting the plurality of battery modules 200, and a cooling member 500 located under the pack case 100.

[0034] First, the pack case 100 is made up of an upper pack case 110 and a lower pack case 120 so as to form a predetermined space.

[0035] The lower pack case 120 has a flat bottom and sides to stably support various components such as the battery modules 200 and the BDU (Battery Disconnect Unit) 300. In particular, a plurality of first slits 121 are formed in a predetermined area of ​​the edge of the bottom, through which vertical parts 420 of the bus bar 400 described below can penetrate and protrude to the upper part of the bottom.

[0036] The upper pack case 110 is coupled to the upper part of the lower pack case 120 and protects various components mounted therein from external impacts.

[0037] The battery module 200 housed inside the pack case 100 includes a plurality of battery cells (not shown) and a module case for protecting the battery cells.

[0038] For example, the battery cell may include a cell case that houses an electrode assembly (not shown) and a pair of electrode leads.

[0039] Here, the electrode assembly may be, but is not limited to, a jelly roll type assembly having a structure in which a separator is interposed between long sheet-like positive and negative electrodes and then wound up; a stack type assembly having a structure in which rectangular positive and negative electrodes are stacked with a separator sandwiched between them; a stack folding type assembly in which unit cells are wound up with a long separator film; or a lamination stack type assembly in which battery cells are stacked with a separator sandwiched between them and attached to each other.

[0040] The electrode assembly is housed in a cell case, and the cell case usually has a laminated sheet structure of an inner layer / metal layer / outer layer. The inner layer must have insulating properties and electrolyte resistance since it is in direct contact with the electrode assembly, and must have sealing properties, i.e., excellent thermal adhesion strength at the sealing portion where the inner layers are thermally bonded to each other, in order to seal against the outside. The material of the inner layer may be selected from polyolefin resins such as polypropylene, polyethylene, polyethylene acetate, and polybutylene, which have excellent chemical resistance and sealing properties, polyurethane resins, and polyimide resins, but is not limited thereto. Polypropylene, which has excellent mechanical properties such as tensile strength, rigidity, surface hardness, and impact strength, and excellent chemical resistance, is the most preferred.

[0041] The metal layer in contact with the internal layer corresponds to a barrier layer that prevents moisture and various gases from penetrating into the interior of the battery from the outside. A suitable material for such a metal layer is a thin aluminum film, which is lightweight yet has excellent formability.

[0042] The other side of the metal layer is provided with an outer layer, which may be made of a heat-resistant polymer having excellent tensile strength, moisture permeability, and air permeability so as to protect the electrode assembly and ensure heat resistance and chemical resistance, such as, but not limited to, nylon or polyethylene terephthalate.

[0043] Meanwhile, the pair of electrode leads includes a positive electrode lead and a negative electrode lead, and may be exposed to the outside of the cell case after the positive electrode tab and the negative electrode tab of the electrode assembly are electrically connected, respectively, or may be directly connected to the electrode assembly without tabs.

[0044] Although the drawings show two battery modules 200 being housed, it goes without saying that this is merely an example, and the number of battery modules 200 housed in the pack case 100 can be changed as desired.

[0045] Next, the BDU (Battery Disconnect Unit) 300 is connected to the battery module 200. adjacent The BDU 300 is mounted on the battery module 200 and connected to the battery module 200 via the bus bar 400 to control the electrical connection of the battery module 200. Since the BDU 300 has a known structure, a detailed description thereof will be omitted.

[0046] FIG. 4 is an exploded perspective view for explaining a connection structure between a bus bar and a cooling member according to the present invention, and FIG. 5 is a cross-sectional view taken along line AA' in FIG.

[0047] 4 and 5, busbar 400 is bent into a predetermined shape. Specifically, busbar 400 is made up of horizontal portion 410 and vertical portions 420 extending vertically from both ends of horizontal portion 410 by a predetermined length.

[0048] The reason why bus bar 400 is bent to form horizontal portion 410 and vertical portion 420 is to allow bus bar 400 to be cooled quickly by contact with cooling member 500 .

[0049] 4 and 5, the horizontal portion 410 of the busbar 400 is located inside the cooling member 500, while the vertical portion 420 passes through the second slit 511 of the cooling member 500 and the first slit 121 of the lower pack case 120 in sequence, and protrudes upward. Of course, the protruding vertical portion 420 of the busbar 400 electrically connects the battery modules 200 and the BDUs 300 to each other.

[0050] Meanwhile, the cooling member 500 is positioned below the lower pack case 120 and cools the heat generated from the battery modules 200 and BDUs (Battery Disconnect Units) 300 seated in the lower pack case 120 , and the bus bars 400 inside the cooling member 500 .

[0051] Here, the cooling member 500 includes a body portion 510 and a cooling pipe 520 embedded inside the body portion 510 .

[0052] Body portion 510 is flat and has a predetermined height and width, and is positioned so that horizontal portion 410 of busbar 400, certain portions of vertical portion 420, and cooling pipe 520 are embedded therein, and it is preferable that cooling pipe 520 is positioned slightly below horizontal portion 410 of busbar 400.

[0053] The material of the body 510 is not particularly limited, but is preferably a thermally conductive plastic, and the body 510, the bus bar 400, and the cooling pipe 520 may be integrally manufactured with each other by insert injection molding.

[0054] In this manner, since the body portion 510, the bus bar 400, and the cooling pipe 520 are integrally molded, there is no need for a separate adhesive or fixing member, which has the advantage of simplifying the manufacturing process.

[0055] In addition, since the horizontal portion 410 of the busbar 400 is located close to the cooling pipe 520 embedded in the body portion 510, not only is a separate cooling means for cooling the busbar 400 unnecessary, but an increase in volume can be suppressed, which also helps to improve the energy density.

[0056] The present invention may be a device including a battery pack having one or more of the features described above, the device may be an electric vehicle, a hybrid vehicle, or a plug-in hybrid electric vehicle.

[0057] Those skilled in the art will appreciate that various applications and modifications within the scope of the present invention are possible based on the above content. [Explanation of symbols]

[0058] 100 pack case 110 Upper pack case 120 Lower Pack Case 121 First Slit 200 Battery Module 300 BDU(Battery Disconnect Unit) 400 Busbar 410 Horizontal part 420 Vertical section 500 Cooling material 510 Body 511 Second Slit 520 Cooling pipe

Claims

1. A pack case having a predetermined space and including an upper pack case and a lower pack case; a plurality of battery modules housed inside the pack case; a bus bar electrically connecting the plurality of battery modules; a cooling member provided in a lower portion of the pack case, the bus bar includes a horizontal portion and a vertical portion extending vertically from both side ends of the horizontal portion, the horizontal portion of the bus bar is located inside the cooling member, and the vertical portion protrudes upward by sequentially passing through a second slit formed in the cooling member and a first slit formed in the lower pack case.

2. The battery pack according to claim 1 , wherein the cooling member includes a body portion and a cooling pipe.

3. A battery pack as described in claim 2, wherein the second slit is formed in the body portion.

4. The battery pack according to claim 2 or 3, wherein the cooling pipe is embedded in the body portion.

5. The battery pack according to any one of claims 2 to 4, wherein a portion of the horizontal portion and a portion of the vertical portion of the bus bar are embedded in the body portion.

6. The battery pack according to claim 5 , wherein the cooling pipe is located relatively lower than the horizontal portion and the vertical portion of the embedded bus bar.

7. The battery pack according to any one of claims 2 to 6, wherein the bus bar, the cooling pipe, and the body portion are integrally molded products.

8. A device comprising the battery pack according to any one of claims 1 to 7.

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