Battery pack and vehicle comprising the same

Abstract

A battery pack according to the disclosure includes a first battery module, a first top cover disposed on the first battery module, a second battery module mounted on the first top cover on top of the first battery module, a second top cover disposed on the second battery module, a top cover middle portion interposed between the first top cover and the second top cover as a cooling device and including a top cover middle portion upper member and a top cover middle portion lower member which are mutually joined by brazing to internally form a cooling water flow space, and a port of the top cover middle portion for cooling water to flow into / out of the cooling water flow space, a lower gasket disposed at a contact area between the first top cover and the top cover middle portion, and an upper gasket disposed at a contact area between the second top cover and the top cover middle portion.

Description

Technical Field

[0001] This disclosure relates to a battery pack and a vehicle including the battery pack, and more specifically, to a battery pack including battery modules mounted in multiple layers and a vehicle including the battery pack. This application claims the benefit of Korean Patent Application No. 10-2020-0134585, filed with the Korean Intellectual Property Office on October 16, 2020, the disclosure of which is incorporated herein by reference in its entirety. Background Technology

[0002] Unlike primary batteries, rechargeable batteries are rechargeable and have a wide range of applications, including not only mobile devices but also electric vehicles (EVs) and hybrid electric vehicles (HEVs) that operate on this power source. Currently widely used types of rechargeable batteries include lithium-ion batteries, lithium-polymer batteries, nickel-cadmium batteries, nickel-metal hydride batteries, and nickel-zinc batteries. A single rechargeable battery cell, i.e., a single cell, operates at a voltage of approximately 2.5V to 4.6V. Therefore, when a higher output voltage is required, multiple cells can be connected in series to configure a battery pack. Furthermore, battery packs can be configured by connecting multiple cells in parallel, depending on the required charge / discharge capacity. Therefore, the number of cells included in a battery pack can be set differently depending on the required output voltage or charge / discharge capacity.

[0003] When configuring a battery pack by connecting multiple battery cells in series or parallel, a battery module comprising at least one battery cell is configured, preferably a battery module comprising multiple battery cells is configured, and then the battery pack is configured using the at least one battery module and adding other components. Here, a battery module refers to an assembly comprising multiple battery cells connected in series or parallel, and a battery pack refers to an assembly comprising multiple battery modules connected in series or parallel to increase capacity and output.

[0004] Typically, to maintain structural stability, vehicle battery packs consist of multiple battery modules or battery module assemblies arranged on the same plane to form a single-layer structure. Battery packs generate heat during charging / discharging, and efficiency decreases when temperatures are too high; therefore, cooling devices are installed beneath the battery modules or battery module assemblies to reduce heat. However, when installing a single-layer battery pack in an electric vehicle requiring high capacity / high output, there are many structural limitations to increasing capacity. Furthermore, it is difficult to structurally expand the cooling system as capacity increases.

[0005] Recently, Korean Patent Publication No. 10-2017-0085681 disclosed a battery pack including battery modules mounted in multiple layers. However, this battery pack includes a cooling water distribution system for cooling the multiple battery modules inside the battery pack. When the cooling water distribution system for cooling the multiple battery modules malfunctions and leaks cooling water, the cooling water comes into direct contact with the electronic components and individual battery cells in the battery pack, leading to dielectric breakdown, fire, or even explosion. Summary of the Invention

[0006] Technical issues

[0007] This disclosure aims to solve the above-mentioned problems. Therefore, this disclosure aims to provide a battery pack that includes battery modules mounted in multiple layers to provide high capacity / high output and has an improved cooling structure to enhance stability.

[0008] This disclosure is further intended to provide a vehicle including the battery pack.

[0009] These and other objects and advantages of this disclosure will be understood from the following description and will become apparent from the embodiments of this disclosure. Furthermore, it will be readily understood that the objects and advantages of this disclosure can be achieved by the means set forth in the appended claims and combinations thereof.

[0010] Technical solution

[0011] To achieve the above objectives, the battery pack according to this disclosure includes: a first battery module; a first top cover disposed on the first battery module; a second battery module mounted on the first top cover on top of the first battery module; a second top cover disposed on the second battery module; a top cover middle portion, which serves as a cooling device inserted between the first top cover and the second top cover and includes an upper member and a lower member of the top cover middle portion joined together by brazing to form a cooling water flow space inside, and a port of the top cover middle portion for cooling water to flow into / out of the cooling water flow space; a lower gasket disposed in a contact area between the first top cover and the top cover middle portion; and an upper gasket disposed in a contact area between the second top cover and the top cover middle portion.

[0012] The port in the middle of the top cover can be exposed outside the first top cover.

[0013] Cooling water can flow in a cooling water flow space parallel to the ground.

[0014] At least one first battery module forms a first battery module assembly, and a second battery module is mounted on top of at least one first battery module of the first battery module assembly, thereby achieving multi-layer mounting.

[0015] The second top cover includes a receiving portion covering the second battery module and a flange disposed on the first top cover around the receiving portion, and the upper part of the middle portion of the top cover includes an edge corresponding to the flange surrounding the cooling water flow space.

[0016] The upper washer can be formed on the edge.

[0017] The lower part of the middle section of the top cover protrudes from the brazing area to the upper part of the middle section of the top cover along the area forming the cooling water flow space, and the lower gasket is disposed between the bottom edge of the first top cover and the bottom of the bottom including the brazing area.

[0018] Fastening members for securing the middle part of the top cover protrude at the outer edge of the first top cover, and the edge of the middle part of the top cover has a groove for the fastening members to be inserted.

[0019] Furthermore, according to this disclosure, a vehicle including the aforementioned battery pack can be provided. The vehicle may include an electric vehicle (EV) or a hybrid electric vehicle (HEV).

[0020] Beneficial effects

[0021] According to this disclosure, a multi-layer mounting structure for installing battery modules with high space utilization can be provided for a battery pack.

[0022] According to this disclosure, a middle portion of the top cover for cooling a second battery module mounted on top is included between the top cover of the first battery pack and the top cover of the second battery pack. Since this corresponds to an external cooling method for the battery pack that does not include a cooling device, when cooling water leaks from the middle portion of the top cover, the leaked cooling water will not directly affect the individual battery cells in the battery pack.

[0023] According to this disclosure, before the middle portion of the top cover is damaged, the upper and lower components of the middle portion of the top cover are brazed together, thus preventing cooling water from leaking through the port in the middle portion of the top cover. Even if the middle portion of the top cover is damaged, the lower and upper gaskets will prevent leaked cooling water from flowing into the battery pack from the middle portion of the top cover. Therefore, stability can be improved by modifying the cooling structure.

[0024] According to this disclosure, the cooling water flows within a cooling water flow space welded by a brazing process, resulting in high cooling efficiency. Therefore, when additional capacity is required in devices demanding high capacity / high output, this additional capacity can be provided by including a second battery module, and the second battery module is effectively cooled to smoothly remove the large amount of heat generated during charging / discharging, thereby ensuring the safety of the battery pack during operation. Attached Figure Description

[0025] The accompanying drawings illustrate preferred embodiments of the present disclosure and, together with the following detailed description of the present disclosure, are intended to provide a further understanding of the technical aspects of the present disclosure; therefore, the present disclosure should not be construed as being limited to the drawings.

[0026] Figure 1 This is a perspective view of a battery pack according to an embodiment of the present disclosure.

[0027] Figure 2 yes Figure 1 A partial exploded perspective view of the battery pack.

[0028] Figure 3 Is Figure 1 Assembly diagram and exploded perspective view of the middle part of the top cover included in the battery pack.

[0029] Figure 4 yes Figure 1 A schematic cross-sectional view of the battery pack.

[0030] Figure 5 This is a diagram illustrating a vehicle according to another embodiment of the present disclosure. Detailed Implementation

[0031] This disclosure will become apparent from the detailed description of preferred embodiments of the disclosure with reference to the accompanying drawings. It should be understood that the embodiments described herein are provided for illustrative purposes to aid in understanding the disclosure, and that the disclosure may be implemented in other forms than those described herein. Furthermore, to aid in understanding the disclosure, the drawings are not shown to scale, and the dimensions of some elements may be enlarged.

[0032] That is, the embodiments described in this specification and the illustrations in the accompanying drawings are only the most preferred embodiments of this disclosure and do not fully describe the technical features of this disclosure. Therefore, it should be understood that other equivalent changes have been made to them when this patent application was filed.

[0033] Figure 1 This is a perspective view of a battery pack according to an embodiment of the present disclosure. Figure 2 yes Figure 1 A partial exploded perspective view of the battery pack. Figure 3 Is Figure 1 Assembly diagram and exploded perspective view of the middle part of the top cover included in the battery pack. Figure 4 yes Figure 1 A cross-sectional schematic diagram of the battery pack.

[0034] refer to Figures 1 to 4 The battery pack 10 includes a tray 100, a first battery module 110, a first top cover 120, a lower gasket 130, a middle part of the top cover 140, an upper gasket 150, a second battery module 160, and a second top cover 170.

[0035] A first battery module 110 is mounted on a tray 100. The tray 100 covers the bottom of the first battery module 110. The first battery module 110 may include a stack of at least one flat battery cell formed into a cubic shape. Preferably, the flat battery cell is a pouch cell. At least one first battery module 110 may form a first battery module assembly. For example, the first battery modules 110 may be mounted in the tray 100 in three rows and three columns. A cooling device (not shown) for cooling the first battery module 110 may be further included at the bottom of the tray 100 or between the tray 100 and the first battery module 110. The cooling device may be a cooling plate including conduits through which cooling water flows, and the cooling device may be mounted in thermal contact with the first battery module 110.

[0036] A first top cover 120 is disposed on the first battery module 110, covering the top of the first battery module 110 to protect its upper surface, and is coupled to the tray 100. The tray 100 and the first top cover 120 may include a flat portion with an area substantially larger than the area of ​​the portion on which the first battery module 110 is mounted. The tray 100 and the first top cover 120 may be disposed on the top and bottom of the first battery module 110 to cover the top and bottom of the first battery module 110, respectively. Fastening members for securing the tray 100 may be inserted into the outer edge of the first top cover 120. Fastening members may include, for example, bolts or rivets. The tray 100 and the first top cover 120 are coupled by the fastening members. Preferably, welding, brazing, or adhesive may be used for the joining, for example.

[0037] The second battery module 160 is mounted on top of the first top cover 120 on the first battery module 110. The second battery module 160 may include a stack of at least one flat battery cell formed into a cubic shape. Preferably, the flat battery cell is a pouch cell. The second top cover 170 is disposed on the second battery module 160 and located on top of the second battery module 160. The second top cover 170 protects the second battery module 160 and is combined with the first top cover 120. The battery pack 10 may further include various devices (not shown), such as electrical components, a battery management system (BMS), current sensors, and fuses, to control the charging / discharging of the first battery module 110 and the second battery module 160, and the first top cover 120 and the second top cover 170 protect these devices.

[0038] The second battery module 160 can be mounted on one first battery module 110, or on at least two first battery modules 110. This embodiment illustrates mounting one second battery module 160 on three first battery modules 110. As described above, in space, the second battery module 160 is mounted on top of the first battery modules 110 to form a multi-layer mounting structure. Therefore, the battery pack 10 of this disclosure can include first battery modules 110 and second battery modules 160 mounted in multiple layers to provide high capacity / high output.

[0039] The top cover center portion 140 is a cooling device inserted between the first top cover 120 and the second top cover 170. The top cover center portion 140 cools the second battery module 160 while in contact with the lower surface of the second battery module 160. The top cover center portion 140 may be a cooling plate including conduits through which cooling water flows, and the top cover center portion 140 may be installed in thermal contact with the second battery module 160.

[0040] Conventional battery packs include a cooling water distribution system for cooling the multi-layered battery modules. In contrast, in the embodiments of this disclosure, a top cover 140 corresponding to the cooling device is inserted between a first top cover 120 and a second top cover 170 to separate the first battery module 110 and the second battery module 160 in the battery pack 10. Even if cooling water leaks, the leaked cooling water will not directly contact the electrical components and individual battery cells in the battery pack 10 protected by the first top cover 120 and the second top cover 170, thus reducing the risk of dielectric breakdown, fire, and explosion.

[0041] The top cover middle portion 140 includes an upper part 142 and a lower part 144 of the top cover middle portion that are brazed together to form a cooling water flow space S inside, and a port 146 of the top cover middle portion for cooling water to flow into / out of the cooling water flow space S. Figure 3 The structure of the middle part 140 of the top cover is shown in detail.

[0042] The upper member 142 of the middle portion of the top cover may have an almost flat surface, and the lower member 144 of the middle portion of the top cover may have a conduit to define the flow path of cooling water. For example, multiple beads or baffles may protrude from the upper surface of the lower member 144 of the middle portion of the top cover to guide the cooling water entering from the port 146 of the middle portion of the top cover in an "S" or zigzag shape in the cooling water flow space S until the cooling water flows out of the port 146 of the middle portion of the top cover. The lower member 144 of the middle portion of the top cover protrudes from the brazing area toward the upper member 142 of the middle portion of the top cover along the region forming the cooling water flow space S.

[0043] The upper component 142 and the lower component 144 of the middle section of the top cover are joined by brazing. Therefore, the risk of leakage of cooling water entering from the port 146 in the middle section of the top cover is extremely low. Furthermore, since the cooling water flows in the cooling water flow space S welded by the brazing process, the cooling efficiency is high.

[0044] Port 146 in the middle of the top cover protrudes beyond the first top cover 120. Cooling water enters and exits through port 146 in the middle of the top cover outside the first top cover 120. Even if port 146 in the middle of the top cover leaks, the cooling water cannot directly contact the first battery module 110 or the second battery module 160 in the battery pack 10. Furthermore, the cooling water flows in a cooling water flow space S parallel to the ground. Efficient cooling can be achieved on the larger surface of the second battery module 160. The temperature of the second battery module 160 can be prevented from rising above a preset temperature by allowing cooling water to flow from the radiator port 146 into the cooling water flow space S.

[0045] The second top cover 170 includes a receiving portion 170a covering the second battery module 160 and a flange 170b disposed on the first top cover 120 surrounding the receiving portion 170a. In addition, the upper part of the middle portion of the top cover 142 includes an edge 142a surrounding the cooling water flow space S corresponding to the flange 170b.

[0046] Fastening members for securing the middle portion 140 of the top cover protrude at the outer edge of the first top cover 120, and the edge 142a of the upper member 142 of the middle portion of the top cover has a groove 142b for inserting the fastening member. The lower washer 130 and the upper washer 150 may also have grooves for inserting the fastening member. The flange 170b of the second top cover 170 engages with the edge 142a of the upper member 142 of the middle portion of the top cover, and thus can be engaged with the first top cover 120 (which is engaged with the upper member 142 of the middle portion of the top cover). Preferably, welding, brazing, or adhesive bonding may be used for the engagement.

[0047] A lower gasket 130 is disposed in the contact area between the first top cover 120 and the middle portion 140 of the top cover for sealing. The lower gasket 130 may be disposed between the first top cover 120 and the bottom of the edge 142a, which includes the bottom of the brazing area. An upper gasket 150 is disposed in the contact area between the second top cover 170 and the middle portion 140 of the top cover for sealing. The upper gasket 150 may be formed on the edge 142a.

[0048] A lower gasket 130 is disposed between the first top cover 120 and the middle portion 140 of the top cover, and an upper gasket 150 is disposed between the middle portion 140 of the top cover and the second top cover 170. The middle portion 140 of the top cover and the interior of the battery pack 10 are separated by the lower gasket 130 and the upper gasket 150. Therefore, even if cooling water leaks from the middle portion 140 of the top cover, the leaked cooling water can be prevented from flowing into the battery pack 10, thereby preventing damage to the individual battery cells.

[0049] In other words, according to this disclosure, before the middle portion 140 of the top cover is damaged, the upper component 142 and the lower component 144 of the middle portion of the top cover are brazed together, so the cooling water entering from the port 146 of the middle portion of the top cover will not leak. Even if the middle portion 140 of the top cover is damaged, the lower gasket 130 and the upper gasket 150 will prevent the cooling water leaking from the middle portion 140 of the top cover from flowing into the battery pack 10. Therefore, stability can be improved by improving the cooling structure.

[0050] Figure 5 This is a diagram illustrating a vehicle according to another embodiment of the present disclosure.

[0051] refer to Figure 5 The vehicle 200 may include the battery pack 10 described in the foregoing embodiments. The vehicle 200 may include an electric vehicle, a hybrid electric vehicle, or other vehicles that use the battery pack 10 as an energy source.

[0052] Since the vehicle 200 according to this embodiment includes the battery pack 10 of the previous embodiment, the vehicle 200 includes all the advantages of the battery pack 10 of the previous embodiment. The battery pack 10 can be installed not only in the vehicle 200, but also in an energy storage system or other equipment or device that uses the battery pack 10 as an energy source.

[0053] Although preferred embodiments of this disclosure have been described and illustrated above, this disclosure is not limited to the specific preferred embodiments described herein. Those skilled in the art can make various modifications to it without departing from the subject matter claimed in this disclosure, and such modifications fall within the scope of the claims.

Claims

1. A battery pack comprising: a first battery module; a first top cover provided on the first battery module; a second battery module mounted on the first top cover on top of the first battery module; a second top cover provided on the second battery module; a top cover intermediate portion interposed between the first top cover and the second top cover as a cooling device, and including a top cover intermediate portion upper member and a top cover intermediate portion lower member which are mutually joined by brazing to internally form a cooling water flow space, and a port of the top cover intermediate portion for cooling water inflow / outflow to / from the cooling water flow space; a lower gasket provided at a contact area between the first top cover and the top cover intermediate portion; and an upper gasket provided at a contact area between the second top cover and the top cover intermediate portion. The port of the top cover intermediate portion is exposed to the outside of the first top cover.

2. The battery pack of claim 1, wherein, The cooling water flows in the cooling water flow space in parallel to the ground.

3. The battery pack of claim 1, wherein, At least one first battery module forms a first battery module assembly, and the second battery module is mounted on top of the at least one first battery module of the first battery module assembly, thereby multi-layer mounting.

4. The battery pack of claim 1, wherein, The second top cover includes a receiving portion covering the second battery module and a flange provided on the first top cover around the receiving portion, and the top cover intermediate portion upper member includes an edge around the cooling water flow space corresponding to the flange.

5. The battery pack of claim 1, wherein, The upper gasket is formed on the edge.

6. The battery pack of claim 5, wherein, The top cover intermediate portion lower member protrudes from a brazing area to the top cover intermediate portion upper member along an area forming the cooling water flow space, and the lower gasket is provided between a bottom of the first top cover and a bottom of an edge including a bottom of the brazing area.

7. The battery pack of claim 5, wherein, A fastening member for fastening the top cover intermediate portion protrudes at an outer edge of the first top cover, and an edge of the top cover intermediate portion has a groove into which the fastening member is inserted.

8. The battery pack of claim 1, wherein, 9. A vehicle including the battery pack according to any one of claims 1 to 8. ​

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