Battery pack and vehicle

Abstract

Battery pack (100) comprising at least one first battery module (1), at least one second battery module (2) and a liquid cooling system (3); wherein the second battery module (2) and the first battery module (1) are stacked in a first direction to form a two-layer battery module; wherein the liquid cooling system (3) comprises a first liquid cooling plate (31) and a second liquid cooling plate (32); wherein the first liquid cooling plate (31) is located at one end of the first battery module (1) and between the first battery module (1) and the second battery module (2); wherein the second liquid cooling plate (32) is located at the end of the second battery module (2) facing away from the first battery module (1).

Description

Technical FieldThe present application relates to the technical field of battery technology, and more particularly, to a battery pack and a vehicle.BackgroundThe 46-th large-cylinder cell has a larger volume, can take up more charge, and has a higher capacity and energy density. With the in-and-out series production of the 46-th Groß cell, the design of battery systems based on the 46-th Cell becomes an important research and development goal for battery systems of new energy vehicles.Disclosure of the ApplicationHowever, in the relevant art, the requirements for the thermal safety and the liquid cooling of the battery system have not been sufficiently taken into account. There are no effective measures for liquid cooling, which results in that the thermal safety of the current dual-layer battery system based on the 46-th large-cylinder cell must be further improved.The present application provides a battery pack. The battery pack includes at least one first battery module, at least one second battery module, and a liquid cooling system. The second battery module and the first battery module are stacked in a first direction to form a two-layer battery module. The liquid cooling system includes a first liquid cooling plate and a second liquid cooling plate. The first liquid cooling plate is located at an end of the first battery module and between the first battery module and the second battery module. The second liquid cooling plate is located at the end of the second battery module facing away from the first battery module.Moreover, in the present application, a vehicle is provided. The vehicle includes the above battery packAdvantageous EffectsThe battery cell provided in this application may form a two-layer battery module by stacking the first battery module and the second battery module. When the battery pack with the two-layer battery module is installed in the vehicle, the vertical space of the vehicle can be fully utilized to meet the high-power, long-range requirements of the vehicle. The first liquid cooling plate and the second liquid cooling plate are respectively attached to the upper surfaces of the first battery module and the second battery module. Thereby, during operation of the battery pack, effective liquid cooling can be performed on the high heat generation regions of the two battery modules, thereby satisfying the liquid cooling requirements of the battery pack and improving the thermal safety of the battery pack.The vehicle provided in this application can meet the high energy, long range requirements of the vehicle while improving thermal safety through the use of the battery pack described above.DESCRIPTION OF THE DRAWINGSFIG. 1 is an exploded view of the battery pack provided in the present application example. FIG. 2 is a perspective view of the battery pack provided in the present application example. FIG. 3 is a cross-sectional view taken along line B-B in FIG. 2. FIG. 4 is a cross-sectional view taken along line A-A in FIG. 2. FIG. 5 is a schematic illustration of the pressure relief process upon thermal cycling of the second battery module according to the present application examples. FIG. 6 is a perspective view of the housing provided in the present application example. FIG. 7 is a schematic diagram showing the structure of the first liquid cooling plate provided in the present application example. FIG. 8 is a schematic diagram of the structure of the vehicle provided in the present application example.Reference Number:100, A battery pack; 1, a first battery module; 10, a first pressure relief chamber; 11, a first cell support; 12, a first battery cell; 13, a first integrated bus bar; 2, a second battery module; 20, a second pressure relief chamber; 21, a second cell support; 22, a second battery cell; 23, a second integrated bus bar; 3, a liquid cooling system; 31, a first liquid cooling plate; 311, a liquid cooling portion; 312, a connection portion; 313, a bypass portion; 32, a second liquid cooling plate; 4, a case; 41, a pressure relief passage; 42, a connection web; 43, a cross member; 5, a case cover; 51, a connection hole; 6, a module frame; 7, a support unit; 71, a support support bracket; 711, a through hole; 8, a heat insulation unit; 200, a vehicle.Embodiments of the ApplicationIn the description of this application, unless expressly stated otherwise and restricted, the terms "connected", "connection" and "attached" are to be understood in the broadest sense. They may comprise, for example, a fixed connection, a detachable connection or an integral embodiment; it may be a mechanical connection or an electrical connection; it may be a direct connection or an indirect connection via an intermediate medium. In addition, it can be a connection or an interaction between two elements within a component or between two components. Those skilled in the art will understand the specific meanings of the above terms in this application in consideration of the circumstances involved.In this application, unless expressly stated otherwise and restricted, the expression that a first feature is arranged "on" or "under" a second feature can encompass both the case that the first and the second feature are directly in contact and the case that the first and the second feature are not directly in contact but are connected via an intermediate feature. Furthermore, the first feature "on", "above" and "above" the second feature comprises both the arrangement of the first feature directly above and obliquely above the second feature, wherein the horizontal height of the first feature is greater than that of the second feature. The first feature "below", "below" and "below" of the second feature comprises both the arrangement of the first feature directly below and obliquely below the second feature, wherein the horizontal height of the first feature is smaller than that of the second feature.In the description of the present embodiments, the terms "upper", "lower", "left", "right", "front" and "rear" refer to the positions or positional relationships illustrated in the drawings. They are for convenience of description and convenience of explanation, and are not intended to express or imply that the stated devices or elements have a particular orientation or must be constructed or operated in a particular orientation. Therefore, they should not be understood as limiting the present application. Moreover, the terms "first / r / s" and "second / r / s" are used for distinction in the specification and have no particular meaning.As shown in FIGS. 1, 3, and 5, the present application provides a battery pack 100 including at least a first battery module 1, at least a second battery module 2, and a liquid cooling system 3. The second battery module 2 and the first battery module 1 are stacked in the first direction X to form a two-layer battery module.By stacking the first battery module 1 and the second battery module 2 in the first direction X to form a two-layer battery module, a battery pack 100 including a two-layer battery module can be formed. When the battery pack 100 is installed in the vehicle, the vertical space of the vehicle can be optimally utilized, thereby satisfying the high energy and long range requirements of the vehicle.Note that the battery pack 100 provided in the present application may include either only one two-layer battery module or a plurality of two-layer battery modules. For example, in FIG. 1, three two-layer battery modules are simultaneously included in the battery pack 100. This means that three second battery modules 2 are each stacked over three first battery modules 1. By including a plurality of two-layer battery modules in the same battery pack 100, the degree of integration of the battery pack 100 can be increased, thereby further satisfying the long-range requirements of the vehicle.As shown in FIGS. 1 and 5, the liquid cooling system 3 includes a first liquid cooling plate 31 and a second liquid cooling plate 32. the first liquid cooling plate 31 is located at an end of the first battery module 1 and between the first battery module 1 and the second battery module 2. the second liquid cooling plate 32 is located at an end of the second battery module 2 remote from the first battery module 1.That is, the first liquid cooling plate 31 and the second liquid cooling plate 32 are respectively attached to the upper surfaces of the first battery module 1 and the second battery module 2, thereby effectively performing liquid cooling at the sites having the greatest heat generation during the operation of the battery pack 100. Thereby, the thermal safety and reliability of the battery pack 100 is improved. The upper side of the first battery module 1 and the second battery module 2 refers to the end of the battery cells at which the tabs are located.It should be understood that the exploded view shown in FIG. 1 is only for illustrating the components of the battery pack 100 provided in the present application example, and not for restricting the positional relationship of the individual components to each other.In some embodiments, the battery pack 100 further includes a housing 4 and a case cover 5. the housing 4 has a storage space in which the first battery module 1, the second battery module 2, and the liquid cooling system 3 are disposed. The case cover 5 covers the case 4.A housing structure accommodating the first battery module 1, the second battery module 2, and the liquid cooling system 3 is formed by the housing 4 and the housing cover 5, thereby providing an effective protective effect for the first battery module 1, the second battery module 2, and the liquid cooling system 3 and improving the structural stability of the battery pack 100 as a whole.In some embodiments, as shown in FIGS. 3-5, the first battery module 1 includes a first cell carrier 11, a plurality of first battery cells 12, and a first integrated bus bar 13. the first cell carrier 11 is disposed at the bottom of the housing 4 and forms a first pressure relief chamber 10 together with the housing 4. The first integrated busbar 13 is arranged on the side of the plurality of first battery cells 12 facing away from the first cell carrier 11 and is connected to the plurality of first battery cells 12. The housing 4 has a pressure relief passage 41, wherein the first pressure relief chamber 10 is connected to both the pressure relief passage 41 and the explosion protection valves of the plurality of first battery cells 12.Specifically, the first cell carrier 11 is disposed inside the housing 4, and the first cell carrier 11 is positioned at a distance from the bottom of the housing 4, thereby forming the first pressure relief chamber 10. A plurality of holes are provided in the first cell carrier 11, wherein the position of each hole corresponds in each case to the position of the explosion protection valve at the base of the respective first battery cell 12. The bottom of the housing 4 has a pressure relief channel 41. When the first cell carrier 11 together with the housing 4 forms the first pressure relief chamber 10, the first pressure relief chamber 10 is in communication with both the pressure relief passage 41 and the explosion protection valves of the plurality of first battery cells 12. When a thermal runaway occurs in one or more of the first battery cells 12, the degassing medium may be discharged into the first pressure relief chamber 10 through the explosion protection valve of the respective first battery cell 12 and then released to the outside of the battery pack 100 through the pressure relief passage 41 connected to the first pressure relief chamber 10.For example, as shown in FIGS. 3 and 5, the battery pack 100 includes three first battery modules 1, and the structure of each first battery module 1 is the same. Each first battery module 1 comprises a first cell carrier 11, a plurality of first battery cells 12 and a first integrated busbar 13. At a circumferential position on the bottom of the housing 4, a pressure relief passage 41 is formed. The first pressure relief chamber 10 is connected to the outside via the pressure relief channel 41, as a result of which venting gases that are produced can be discharged to the outside.In some embodiments, as shown in FIGS. 3 to 5, the battery pack 100 further includes a module frame 6 disposed above the first liquid cooling plate 31. The second battery module 2 comprises a second cell carrier 21, a plurality of second battery cells 22 and a second integrated busbar 23. A second pressure relief chamber 20 is formed between the second cell carrier 21 and the module frame 6. The plurality of second battery cells 22 are installed in the second cell carrier 21. The second integrated busbar 23 is arranged on the side of the plurality of second battery cells 22 facing away from the second cell carrier 21 and is connected thereto.A support unit 7 is arranged between the first cell carrier 11 and the module frame 6, wherein a through hole 711 is formed in the support unit 7. The first pressure relief chamber 10 and the second pressure relief chamber 20 communicate with each other via the through hole 711. Moreover, the second pressure relief chamber 20 communicates with the safety valves of the plurality of second battery cells 22.The support unit 7 is capable of supporting the module frame 6 and the second battery module 2 disposed above the module frame 6. At the same time, a vertically extending through hole 711 is formed in the support unit 7, whereby the first pressure relief chamber 10 and the second pressure relief chamber 20 can be connected to each other. A plurality of openings are likewise formed in the second cell carrier 21, wherein the position of each opening corresponds to the position of the safety valve of each second battery cell 22. When one or more of the second battery cells 22 enter a thermal runaway condition, the venting gases may be discharged through the safety valves at the bottom of the second battery cells 22 into the second pressure relief chamber 20. Subsequently, the ventilation gases flow into the first pressure relief chamber 10 through the through hole 711 formed in the support unit 7, and are finally discharged to the outside of the battery pack via the pressure relief passage 41 connected to the first pressure relief chamber 10.For example, as shown in FIGS. 3 and 4, the support unit 7 includes a plurality of support beams 71. the plurality of support beams 71 are respectively disposed at the four corners and in the longitudinal central portion of the first cell support plate 11, whereby good support of the module frame 6 and the second battery module 2 can be ensured. Each support bracket 71 is provided with a through hole 711 in the vertical direction, whereby the first pressure relief chamber 10 and the second pressure relief chamber 20 are connected to each other through the through hole 711. The module frame 6 may be an aluminum alloy module frame.FIG. 5 shows a schematic illustration of the pressure relief process when a thermal runaway occurs in the second battery cell 22 of the second battery module 2. The direction indicated by arrows in the figure indicates the flow direction of the pressure relief gas. When one of the second battery cells 22 is thermally flown through, the pressure relief gas is released through the safety valve of the second battery cell 22 and enters the second pressure relief chamber 20 through a hole disposed at the corresponding position of the second cell support plate 21, then flows into the first pressure relief chamber 10 through the through hole 711 in the support unit 7, and is finally discharged to the outside of the battery pack 100 through the pressure relief passage 41 connected to the first pressure relief chamber 10.In the embodiment of this application, the first pressure relief chamber 10 and the second pressure relief chamber 20 are designed to be connected to the safety valves of the first battery cell 12 and the second battery cell 22, respectively. Moreover, the second pressure relief chamber 20 and the first pressure relief chamber 10 are connected to each other, and the first pressure relief chamber 10 is connected to the outside world through the pressure relief passage 41 disposed in the housing 4. This forms a relatively closed pressure relief space which permits gas-electrical separation when a thermal runaway of the battery cells occurs. This prevents the pressure release gas from interfering with other components in the battery pack 100, thereby further improving the thermal safety of the battery pack 100.In some embodiments, as shown in FIG. 5, the battery pack 100 also includes a thermal insulation unit 8. the thermal insulation unit 8 is located between the first liquid cooling plate 31 and the second battery module 2 and / or on the surface of the second liquid cooling plate 32 facing away from the second battery module 2.The thermal insulation unit 8 can effectively isolate the gases released during a thermal runaway. For example, the heat insulation unit 8 may prevent the pressure relief gases generated by the second battery module 2 from damaging the first liquid cooling plate 31 located thereunder and the first battery module 1 when the second battery module 2 thermally passes through.For example, as illustrated in FIG. 5, the heat insulation unit 8 is disposed between the first liquid cooling plate 31 and the second battery module 2, and abuts on the surface of the first liquid cooling plate 31. It serves to isolate the heat generated during operation or during thermal runaway of the second battery module 2.In some embodiments, the heat insulation unit 8 is made of a mica plate. The mica plate has excellent high temperature resistance and can improve heat insulation efficiency.In some embodiments, the battery pack 100 further includes a first thermally conductive structural adhesive layer and a second thermally conductive structural adhesive layer. Here, the first heat conductive structural adhesive layer is disposed between the first liquid cooling plate 31 and the first battery module 1; the second heat conductive structural adhesive layer is disposed between the second liquid cooling plate 32 and the second battery module 2.In other words, the first liquid cooling plate 31 and the first battery module 1 are firmly joined to each other by the first heat conductive structural adhesive layer, while the second liquid cooling plate 32 and the second battery module 2 are firmly joined to each other by the second heat conductive structural adhesive layer. This configuration not only ensures the thermal conductivity of the liquid cooling plates but also increases the stability of the joint.In some embodiments, as shown in FIG. 7, escape portions 313 are provided on the first liquid cooling plate 31 and the second liquid cooling plate 32. The positions of the escape portions 313 correspond to the positions of the components inside the housing 4; and / or the positions of the escape portions 313 correspond to the positions of the components of the housing cover 5.Specifically, the escape portion 313 includes at least one of the following shapes: protrusion, depression, or recess. By providing the escape portion 313, interference between the first liquid cooling plate 31 and the second liquid cooling plate 32 with the components in the housing 4 and the components in the housing cover 5 can be prevented.In some embodiments, a plurality of connecting bars 42 are disposed in the housing 4, and connecting holes 51 are provided at the respective positions of the housing cover 5 corresponding to the connecting bars 42. The connecting webs 42 are inserted into the connecting bores 51, wherein the deflection section 313 corresponds to the position of the connecting webs 42.By way of example, the plurality of connecting webs 42 arranged in the housing 4 are designed as internal threaded columns, connecting bores 51 being provided at the corresponding positions of the housing cover 5. By means of screws, the housing cover 5 and the housing 4 can be firmly connected to each other, thereby improving the stability of the entire structure.Specifically, as illustrated in FIG. 6, two cross members 43 are disposed at the middle position in the height direction of the housing 4. On each cross member 43, two connecting webs 42 are arranged at a distance from one another. The connecting webs 42 and the connecting bores 51 together form a central ceiling suspension structure which can be used for lifting the battery pack 100.Moreover, when the battery pack 100 includes a plurality of first battery modules 1 and a plurality of second battery modules 2, the first liquid cooling plate 31 and the second liquid cooling plate 32 need to cover a plurality of first battery modules 1 and a plurality of second battery modules 2, respectively. As illustrated in FIG. 7, it is explained using the example of the first liquid cooling plate 31 that the first liquid cooling plate 31 includes a liquid cooling portion 311 and a connecting portion 312. A liquid cooling passage is disposed in the liquid cooling portion 311. Each liquid cooling portion 311 can effectively cover a first battery module 1, thereby improving the heat dissipation capacity of the first battery module 1. The connecting portion 312 serves for connecting two adjacent liquid cooling portions 311. The escape portion 313 is disposed in the connecting portion 312 and formed as a recess, thereby bypassing the position of the connecting web 42 to avoid interference with the connecting web 42.That is, the escape portion 313 in the first liquid cooling plate 31 releases the position of the connecting web 42. A recess is provided at the corresponding position of the connecting web 42, thereby avoiding the problem of interference between the first liquid cooling plate 31 and the connecting web 42.Note that, when other components that may interfere with the first liquid cooling plate 31 and / or the second liquid cooling plate 32 are present in the battery pack 100, other escape portions 313 may also be provided at the corresponding interference positions. For example, an escape portion 313 may be provided at the portion of the first liquid cooling plate 31 corresponding to the support unit 7. In some embodiments, the first battery cell 12 and the second battery cell 22 are 46-degree large-cylinder cells.The 46-th large-cylinder cell has a larger volume capable of receiving more charge and has a higher capacity and a higher energy density. For example, the 46th GROß cell includes at least one of the following cells: 4680 cell, 4695 cell, and 46120 cell.Second Aspect. As shown in FIG. 8, an embodiment of the present application provides a vehicle 200 including the above-described battery pack 100.In an embodiment of the present application, by stacking the first battery module 1 and the second battery module 2, a battery pack 100 including a double-layer battery module can be formed. When the battery pack 100 is installed in the vehicle 200, the space of the vehicle in the Z direction can be optimally utilized to meet the high-power, long-range requirements of the vehicle 200. On the upper surface of the first battery module 1 and the second battery module 2, a first liquid cooling plate 31 and a second liquid cooling plate 32 are respectively disposed. During operation of the battery pack, the first battery module 1 and the second battery module 2 can each be effectively liquid-cooled, thereby meeting the liquid-cooling requirements of the battery pack 100. This increases the thermal safety and reliability of the battery pack 100, and thus improves the safety of the vehicle 200.

Claims

A battery pack (100) comprising at least a first battery module (1), at least a second battery module (2), and a liquid cooling system (3); wherein the second battery module (2) and the first battery module (1) are stacked in a first direction to form a two-layer battery module; wherein the liquid cooling system (3) comprises a first liquid cooling plate (31) and a second liquid cooling plate (32); wherein the first liquid cooling plate (31) is located at an end of the first battery module (1) and between the first battery module (1) and the second battery module (2); wherein the second liquid cooling plate (32) is located at the end of the second battery module (2) remote from the first battery module (1).The battery pack (100) according to claim 1, further comprising a housing (4) and a case lid (5); wherein the first battery module (1), the second battery module (2), the first liquid cooling plate (31), and the second liquid cooling plate (32) are all disposed inside the housing (4); wherein the case lid (5) is coverably attached to the housing (4).The battery pack (100) according to claim 2, wherein the first battery module (1) comprises a first cell support sheet (11), a plurality of first battery cells (12), and a first integrated bus bar (13); wherein the first cell support sheet (11) is disposed at the bottom of the housing (4) and forms a first pressure relief chamber (10) with the housing (4); wherein a plurality of the first battery cells (12) are mounted on the first cell support sheet (11); wherein the first integrated bus bar (13) is disposed on the side of the plurality of first battery cells (12) facing away from the first cell support sheet (11) and connected to the plurality of first battery cells (12); wherein the housing (4) is provided with a pressure relief channel (41), the first pressure relief chamber (10) communicates with both the pressure relief channel (41) and the safety valves of the plurality of first battery cells (12).The battery pack (100) according to claim 3, wherein the battery pack (100) further comprises a module frame (6) disposed between the first liquid cooling plate (31) and the second battery module (2); wherein the second battery module (2) comprises a second pressure relief chamber (21), a plurality of second battery cells (22), and a second integrated bus bar (23); wherein the second pressure relief chamber (21) is disposed on the side of the module frame (6) opposite the first liquid cooling plate (31), and the second pressure relief chamber (21) forms the second pressure relief chamber (20) together with the module frame (6); wherein the plurality of second battery cells (22) are installed in the second pressure relief chamber (21); wherein the second integrated bus bar (23) is disposed on the side of the plurality of second battery cells (22) opposite the second pressure relief chamber (21) and is connected to the plurality of second battery cells (22); wherein between the first cell support plate (11) and the module frame (6) a support unit (7) is arranged, in which a through hole (711) is provided; wherein the first pressure relief chamber (10) and the second pressure relief chamber (20) are connected to each other via the through hole (711), and wherein the second pressure relief chamber (20) is connected to the pressure relief valves of the plurality of second battery cells (22).The battery pack (100) according to claim 4, wherein the support unit (7) comprises a plurality of support beams (71), the through hole (711) being disposed in the support beams (71).The battery pack (100) according to any one of claims 1 to 5, wherein the battery pack (100) further comprises a heat insulation unit (8), wherein the heat insulation unit (8) is arranged between the first liquid cooling plate (31) and the second battery module (2), and / or the heat insulation unit (8) is arranged on the side of the second liquid cooling plate (32) facing away from the second battery module (2).The battery pack (100) according to claim 6, wherein the heat insulation unit (8) is a mica plate.The battery pack (100) according to any one of claims 1 to 7, wherein the battery pack (100) further comprises a first heat conductive structural adhesive layer and a second heat conductive structural adhesive layer; wherein the first heat conductive structural adhesive layer is disposed between the first liquid cooling plate (31) and the first battery module (1); wherein the second heat conductive structural adhesive layer is disposed between the second liquid cooling plate (32) and the second battery module (2).The battery pack (100) according to any one of claims 2 to 8, wherein an escape portion (313) is provided on the first liquid cooling plate (31) and the second liquid cooling plate (32), the escape portion (313) corresponding to the position of the components inside the case (4); and / or the escape portion (313) corresponding to the position of the components of the case cover (5).Battery pack (100) according to Claim 9, wherein a plurality of connecting webs (42) are arranged in the interior of the housing (4), wherein connecting openings (51) are provided at the position of the housing cover (5) corresponding to the connecting web (42), the connecting webs (42) are inserted into the connecting openings (51), wherein the deflection section (313) corresponds to the position of the connecting webs (42).The battery pack (100) according to claim 10, wherein a plurality of cross members (43) are disposed inside the housing (4), the connecting bars (42) being disposed on the cross members (43).The battery pack (100) according to claim 11, wherein the connecting webs (42) comprise internally threaded columns, a bolt being passed through the connecting opening (51) and being fixedly connected to the connecting webs (42), such that the housing cover (5) and the housing (4) are fixedly connected to each other.The battery pack (100) according to any one of claims 9 to 12, wherein the first liquid cooling plate (31) and the second liquid cooling plate (32) include a liquid cooling portion (311) and a connection portion (312); each of the liquid cooling portions (311) respectively covers a first battery module (1) or a second battery module (2), the connection portion (312) being configured to connect two adjacent liquid cooling portions (311) to each other.The battery pack (100) according to claim 13, wherein the escape portion (313) is provided at the connection portion (312).A vehicle (200) comprising a battery pack (100) according to any one of claims 1 to 14.

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