Battery pack and energy storage system

Abstract

The present disclosure relates to the technical field of secondary batteries. Disclosed are a battery pack and an energy storage system. The battery pack comprises a housing and a battery module; the battery module comprises a plurality of battery cells arranged in a first direction; a partition plate and a first baffle are provided between a top surface of the battery module and a top wall of the housing; the partition plate covers the top surface of the battery module; one end of the first baffle abuts against the top wall of the housing, and the other end thereof abuts against the battery module or the partition plate; the first baffle surrounds the periphery of the top surface of the battery module; the partition plate, the top wall of the housing, and the first baffle form a first exhaust channel; an explosion-proof valve is provided on a side wall of the housing, and the explosion-proof valve is communicated with an outlet of the first exhaust channel; the plurality of battery cells are each provided with a pressure relief valve; the partition plate comprises a plurality of valve actuation structures; and the plurality of valve actuation structures are respectively arranged opposite to the pressure relief valves of the plurality of battery cells. The first exhaust channel blocks the ejected substances from the battery cells from spreading to the outer side and bottom region of the battery module, thereby avoiding the aggravation of thermal runaway and the risk of electrical runaway, improving the safety of the battery pack.

Description

Battery packs and energy storage systems

[0001] This application claims priority to Chinese Patent Application No. 202421659760.9, filed on July 12, 2024, entitled “Battery Pack and Energy Storage System”, the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of secondary battery technology, and particularly to battery packs and energy storage systems. Background Technology

[0003] A battery pack, as a battery energy storage unit, comprises one or more battery modules, each containing multiple cells connected in series or parallel. When a cell in the battery pack experiences thermal runaway, the high-temperature fumes, electrolyte, solid particles, and other ejected contaminants can easily spread within the battery pack, potentially triggering secondary combustion. Therefore, it is necessary to promptly remove these contaminants from the battery pack.

[0004] The battery pack provided by the related technology uses the gap between the top of the battery module and the top wall of the battery pack housing as a flue, and installs an explosion-proof valve on the side wall of the battery pack housing. The flue collects the ejected material from the battery cells. When the pressure inside the flue reaches a set value, the explosion-proof valve opens, allowing the ejected material from the battery cells to be discharged to the outside of the battery pack.

[0005] However, during the process of the battery cell ejecting material from the battery cell into the flue, the ejected material is prone to splashing everywhere. Once it spreads to other battery cells, metal components and electrical components inside the battery pack, it will lead to aggravated thermal runaway. Summary of the Invention

[0006] This application provides a battery pack and energy storage system, which can solve the technical problems existing in related technologies. Specifically, the technical solution is as follows:

[0007] On one hand, a battery pack is provided, the battery pack including a housing and a battery module, the housing for accommodating the battery module, the battery module including multiple battery cells arranged along a first direction; a partition and a first enclosure are disposed between the top surface of the battery module and the top wall of the housing, the partition covering the top surface of the battery module, one end of the first enclosure abutting against the top wall of the housing, the other end of the first enclosure abutting against the battery module or the partition, and the first enclosure surrounding the periphery of the top surface of the battery module; the partition, the top wall of the housing, and the first enclosure form a first flue, the first flue having an outlet, an explosion-proof valve being disposed on the side wall of the housing, the explosion-proof valve communicating with the outlet of the first flue; each of the multiple battery cells is provided with a pressure relief valve, the partition including multiple valve opening structures, the multiple valve opening structures being respectively disposed opposite to the pressure relief valves of the multiple battery cells.

[0008] The battery pack provided in this application embodiment covers the top surface of the battery module with a separator, and a first enclosure is provided between the top wall of the housing and the separator. Thus, the separator, the first enclosure, and the top wall of the housing cooperate to form a first flue. The battery module is isolated from the first flue by the separator. When a cell experiences thermal runaway, the ejected material from the cell is ejected through the cell's pressure relief valve and impacts the valve opening structure on the separator, causing it to open and be discharged into the first flue. By having both ends of the first enclosure abut against the top wall of the housing and the battery module (or separator), and surrounding the top periphery of the battery module, the first enclosure can seal off the open areas of the first flue except for its outlet area. This effectively prevents the ejected material from the cell entering the first flue from spreading to the outer and bottom areas of the battery module. Instead, it is guided through the outlet of the first flue to the explosion-proof valve and discharged to the outside of the battery pack. It is evident that by setting up the first flue to block the spread of cell ejection material to the outer and bottom areas of the battery module, the spread of cell ejection material to other cells, metal components, and electrical components inside the battery pack is effectively prevented, thereby avoiding the risk of aggravated thermal runaway and electrical runaway, and improving the safety of the battery pack.

[0009] In some possible implementations, multiple battery modules are arranged side by side along a second direction, wherein the second direction is perpendicular to the first direction; the first enclosure is also disposed between any two adjacent battery modules to divide the first flue into multiple mutually isolated sub-flues, each sub-flue corresponding to one of the battery modules.

[0010] In some possible implementations, the first enclosure member has a first elastic member and a second elastic member at its two ends, respectively; the first elastic member abuts against the top wall of the housing, and the second elastic member abuts against the partition or the battery module.

[0011] In some possible implementations, the first enclosure member includes a rigid baffle, and the first elastic member and the second elastic member are respectively connected to both ends of the rigid baffle.

[0012] In some possible implementations, the first enclosure includes: a first barrier section, a second barrier section, and a third barrier section distributed sequentially along a direction perpendicular to the top wall of the housing, wherein one of the first barrier section and the third barrier section abuts against the top wall of the housing, and the other abuts against the battery module or the separator; the cross-sectional area of ​​the second barrier section is smaller than the cross-sectional areas of the first barrier section and the third barrier section, wherein the cross-sectional area is the area of ​​a cross section parallel to the top wall of the housing.

[0013] In some possible implementations, the first enclosure member is H-shaped.

[0014] In some possible implementations, the plurality of valve opening structures include at least one of a tear line and a valve plate; the tear line includes a plurality of spaced-apart through holes; the valve plate has a notch or through holes.

[0015] In some possible implementations, the partition is a ceramic composite strip, and the plurality of valve opening structures are tear lines.

[0016] In some possible implementations, the first enclosure member is arranged to surround a portion of the peripheral area of ​​the top surface of the battery module, and the gap between the two ends of the first enclosure member distributed circumferentially serves as the outlet of the first flue.

[0017] In some possible implementations, the battery pack further includes a second enclosure located between the first sidewall of the battery module and the first sidewall of the housing to form a second flue between the first sidewall of the battery module and the first sidewall of the housing. The first sidewall of the housing is provided with the explosion-proof valve, and the first sidewall of the battery module faces the first sidewall of the housing. The outlet of the first flue, the second flue, and the explosion-proof valve are sequentially connected, and the projection of the explosion-proof valve on the first sidewall of the battery module is located within the second flue.

[0018] A second insulating spacer is provided between the first sidewall of the battery module facing the explosion-proof valve and the corresponding sidewall of the housing to form a second flue. The second flue is isolated from the cold plate assembly, thereby preventing cell ejection from spreading to the cold plate assembly exposed in that area.

[0019] In some possible implementations, the second enclosure member is connected to the first sidewall of the battery module, and the second enclosure member is located at both ends of the first sidewall of the battery module distributed along a second direction, and at the bottom end of the first sidewall of the battery module, wherein the second direction is perpendicular to the first direction.

[0020] In some possible implementations, the first enclosure is arranged to surround the entire peripheral area of ​​the top surface of the battery module, and the side wall of the first enclosure adjacent to the explosion-proof valve has an opening, which serves as the outlet of the first flue.

[0021] In some possible implementations, the battery pack further includes a flow guide pipe, one end of which is connected to the outlet of the first flue, and the other end of which is connected to the explosion-proof valve.

[0022] On the other hand, embodiments of this application provide an energy storage system, which includes: a power converter and at least one battery pack as described above; the power converter is used to convert the voltage output by the battery pack into power and output it to the power grid or a load, and / or to convert the voltage output by an external power source into power and output it to the battery pack. Attached Figure Description

[0023] Figure 1 is an exploded view of an exemplary battery pack provided in an embodiment of this application from a top-down perspective;

[0024] Figure 2 is a partial exploded view of the battery pack shown in Figure 1 from a side view.

[0025] Figure 3 is a cross-sectional view of an exemplary battery pack provided in an embodiment of this application;

[0026] Figure 4 is a partial structural schematic diagram of another exemplary battery pack provided in an embodiment of this application;

[0027] Figure 5 is a cross-sectional view of another exemplary battery pack provided in an embodiment of this application;

[0028] Figure 6 is a schematic diagram of the first structure of an exemplary first enclosure member provided in an embodiment of this application;

[0029] Figure 7 is a schematic diagram of the second structure of an exemplary first enclosure member provided in an embodiment of this application;

[0030] Figure 8 is a first structural schematic diagram of an exemplary partition provided in an embodiment of this application;

[0031] Figure 9 is a schematic diagram of the second structure of an exemplary partition provided in an embodiment of this application;

[0032] Figure 10 is a partial structural schematic diagram of another exemplary battery pack provided in an embodiment of this application;

[0033] Figure 11 is another partial structural schematic diagram of the battery pack shown in Figure 10;

[0034] Figure 12 is a partial structural schematic diagram of another exemplary battery pack provided in an embodiment of this application;

[0035] Figure 13 is a partial structural schematic diagram of another exemplary battery pack provided in an embodiment of this application.

[0036] The reference numerals in the attached drawings represent: 1. Shell; 11. Cover; 110. Top wall of the shell; 12. Seat; 2. Explosion-proof valve; 3. Battery module; 31. Cell; 310. Pressure relief valve; 32. Busbar; 33. Terminal post; 4. Partition; 40. Valve opening structure; 401. Tear line; 402. Valve plate; 5. First enclosure component; 501. Rigid baffle; 502. First elastic component; 503. Second elastic component; 51. First barrier section; 52. Second barrier section; 53. Third barrier section; 6. Second enclosure component; 7. Guide pipe; 8. Cold plate assembly; 9. High-voltage electrical compartment; 001. First flue; 0011. Outlet; 0010. Sub-flue; 002. Second flue. Detailed Implementation

[0037] In the description of the embodiments of this application, the terms "upper", "lower", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. The orientation may change when the product is placed in different postures, and therefore should not be construed as a limitation on the embodiments of this application.

[0038] Typically, a battery pack includes a metal casing, inside which are battery modules, a cold plate assembly, electrical components, and other parts. The cold plate assembly is usually located at the bottom of the battery module and typically includes a liquid cooling plate, usually made of metal. A busbar is located at the top of the battery module, and this busbar includes at least an aluminum busbar that connects to the terminals of each cell within the battery module. A high-voltage electrical compartment is formed between one side of the battery module and the metal casing, and the electrical components are usually housed within this compartment.

[0039] When a cell in a battery pack experiences thermal runaway, the ejected material includes high-temperature fumes, electrolyte, and solid particles. This mixture of gas, liquid, and solid ejected material not only releases heat at high temperatures, causing further thermal diffusion, but can also trigger an electric arc through insulation breakdown. The high-temperature arc can reach temperatures as high as 2000°C, which can break down metal structural components (such as the aforementioned liquid cooling plates, aluminum busbars, and electrical components), causing more serious short circuits, insulation failure, and other electrical diffusion phenomena, ultimately leading to the deflagration of the entire battery pack.

[0040] To address the aforementioned technical issues, it is essential to prevent the spread of cell ejecta within the battery pack, which could lead to secondary combustion. Therefore, timely removal of cell ejecta from the battery pack is crucial.

[0041] In the battery packs provided by related technologies, the gap between the top of the battery module and the top wall of the battery pack casing serves as a flue, and an explosion-proof valve is installed on the side wall of the battery pack casing. The flue collects ejected material from the battery cells. When the pressure inside the flue reaches a set value, the explosion-proof valve opens, allowing the ejected material to be discharged outside the battery pack. However, during the process of ejecting material from the battery cells into the flue, the material splashes everywhere inside the flue. If this material spreads to other battery cells, metal components, and electrical components inside the battery pack, it will exacerbate thermal runaway.

[0042] To address the technical problems existing in related technologies, this application provides a battery pack, as shown in Figures 1-3. The battery pack includes a housing 1 and a battery module 3. The housing 1 houses the battery module 3, which includes multiple battery cells 31 (see Figure 1). The multiple battery cells 31 are arranged along a first direction. A partition 4 and a first enclosure 5 are provided between the top surface of the battery module 3 and the top wall of the housing 1 (see Figure 3). The partition 4 covers the top surface of the battery module 3. One end of the first enclosure 5 abuts against the top wall of the housing 1, and the other end abuts against either the battery module 3 or the partition 4. The first enclosure 5 surrounds the periphery of the top surface of the battery module 3. The partition 4, the top wall of the housing 1, and the first enclosure 5 form a first flue 001. The first flue 001 has an outlet 0011. An explosion-proof valve 2 is provided on the side wall of the housing 1, and the explosion-proof valve 2 communicates with the outlet 0011 of the first flue 001. Each of the multiple battery cells 31 is equipped with a pressure relief valve 310, and the partition 4 includes multiple valve opening structures 40, which are respectively arranged opposite to the pressure relief valves 310 of the multiple battery cells 31.

[0043] It should be noted that, as shown in Figure 3, the battery module 3 includes multiple battery cells 31. One end of each battery cell 31 is provided with a terminal post 33 (including a negative terminal post and a positive terminal post) and a pressure relief valve 310. For example, the pressure relief valve 310 may be located between two terminals 33. The battery module 3 also includes a busbar 32, which covers the terminals 33 of the multiple battery cells 31 to achieve electrical connection between the battery cells 31. The side of the battery module 3 facing away from the busbar 32 is usually in contact with the cold plate assembly 8, which is used to dissipate heat from the battery module 3.

[0044] For the battery pack housing 1, the top wall 110 of the housing 1 refers to the wall of the housing 1 facing the busbar 32 of the battery module 3, the bottom wall of the housing 1 refers to the wall of the housing 1 used to support the cold plate assembly 8, and the side wall of the housing 1 refers to the wall connecting the top wall 110 and the bottom wall of the housing 1. The side wall of the housing 1 is arranged around the battery module 3. In some examples, as shown in Figure 1, the battery pack housing 1 includes a cover 11 and a base 12, wherein the top wall 110 of the housing 1 is provided by the cover 11, the bottom wall of the housing 1 is provided by the base 12, and the side wall of the housing 1 is provided by at least one of the cover 11 and the base 12. For example, Figure 1 illustrates that the cover 11 has a cover structure, the top surface of the cover 11 serves as the top wall 110 of the housing 1, and the side wall of the cover 11 serves as the side wall portion of the housing 1.

[0045] Based on the orientations shown in Figures 1-13 of the embodiments of this application, the orientation of the top wall 110 of the housing 1 can be defined as "top" or "upper", and correspondingly, the orientation of the base 12 of the housing 1 can be defined as "bottom" or "lower".

[0046] The first enclosure 5 is made of insulating material to provide insulation. In the horizontal direction shown in Figure 1, the first enclosure 5 is arranged around the top periphery of the battery module 3. The first enclosure 5 can be an integral partition or multiple separate partitions, as long as it can be arranged around the top periphery of the battery module 3. In the vertical direction shown in Figure 1, the top end of the first enclosure 5 abuts against the top wall 110 of the housing 1, and the bottom end of the first enclosure 5 abuts against the top surface of the battery module 3 or the top surface of the partition 4. Thus, the first enclosure 5 closes at least a portion of the open side of the first exhaust duct 001, thereby forming an independent exhaust channel above the battery module 3. Therefore, the first exhaust duct 001 is also called an independent exhaust channel (IEC). The first exhaust duct 001 is isolated from the battery module 3 by the partition 4, achieving effective protection for the battery module 3.

[0047] The separator 4 is made of insulating material to provide insulation. The separator 4 can be a single plate or a combination of multiple plates, depending on the actual requirements. The separator 4 covers the top surface of the battery module 3 facing the top wall 110. The arrangement of the separator 4 on the top surface of the battery module 3 can include the following implementation schemes:

[0048] In one embodiment, as shown in Figure 3, the separator 4 covers the busbar 32 of the battery module 3. Thus, the outermost surfaces of the cell shells 31 located outside the outermost terminals 33 of the cells in the battery module 3 are not covered by the separator 4. In this case, the lower end of the first retaining member 5 can abut against the top surface of the cell shells of the battery module 3 that are not covered by the separator 4. Furthermore, in this embodiment, the separator 4 can be a single-plate type. In another embodiment, the separator 4 covers all the top surfaces of the battery module 3. In this case, the lower end of the first retaining member 5 can abut against the corresponding top surface of the separator 4. Furthermore, in this embodiment, the separator 4 can be a single-plate type.

[0049] The partition 4 includes multiple valve opening structures 40, which are respectively arranged opposite to the pressure relief valves 310 of multiple battery cells 31. That is, each pressure relief valve 310 of battery cell 31 corresponds to one valve opening structure 40. When a certain pressure relief valve 310 is opened, the valve opening structure 40 can be quickly opened under the impact of the battery cell ejection material, so that the valve opening structure 40 opened by the battery cell ejection material from the battery cell 31 is introduced into the first flue 001.

[0050] The battery pack provided in this application embodiment covers the top surface of the battery module 3 with a partition 4, and a first enclosure 5 is provided between the top wall 110 of the housing 1 and the partition 4. Thus, the partition 4, the first enclosure 5, and the top wall 110 of the housing 1 cooperate to form a first flue 001. The battery module 3 is isolated from the first flue 001 by the partition 4. When a cell 31 experiences thermal runaway, the ejected material from the cell is ejected through the pressure relief valve 310 of the cell 31 and impacts the valve opening structure 40 on the partition 4 to open it, thereby leading it into the interior of the first flue 001. By having both ends of the first enclosure 5 abut against the top wall 110 of the housing 1 and the battery module 3 (or partition 4) respectively, and by surrounding the top periphery of the battery module 3, the first enclosure 5 can seal off the open areas of the first flue 001 except for its outlet 0011 area. This effectively prevents the ejected material from the battery cells entering the first flue 001 from spreading to the outer and bottom areas of the battery module 3. Instead, it is guided through the outlet 0011 of the first flue 001 to the explosion-proof valve 2 and discharged to the outside of the battery pack. Therefore, by setting the first flue 001 to block the spread of ejected material from the battery cells to the outer and bottom areas of the battery module 3, the spread of ejected material to other cells, metal components, and electrical components inside the battery pack is effectively prevented, thereby avoiding the risk of increased thermal runaway and electrical runaway, and improving the safety of the battery pack.

[0051] The first flue 001 has an outlet 0011 that connects to the explosion-proof valve 2. The outlet 0011 of the first flue 001 can be adjacent to and connected to the explosion-proof valve 2. For example, the explosion-proof valve 2 can be located on the side wall of the battery pack housing 1, and the outlet 0011 of the first flue 001 can be positioned opposite the side wall of the housing 1 where the explosion-proof valve 2 is located. The proximity of the outlet 0011 of the first flue 001 to the explosion-proof valve 2 facilitates the rapid and direct introduction of ejected material from the battery cells into the explosion-proof valve 2, reducing the exit path of the ejected material within the battery pack and further decreasing the probability of the ejected material spreading to other battery cells, metal components, and electrical components within the battery pack.

[0052] The battery pack typically contains multiple battery modules 3, as shown in Figure 4. The multiple battery modules 3 are arranged side by side along the second direction. The first enclosure 5 can be arranged to enclose at least part of the peripheral area of ​​the module as a whole composed of multiple battery modules 3. Furthermore, as shown in Figures 4 and 5, the first enclosure 5 is also disposed between any two adjacent battery modules 3 to divide the first flue 001 into multiple mutually isolated sub-flues 0010, with each sub-flue 0010 corresponding to a battery module 3.

[0053] For these first enclosure members 5 set between any two adjacent battery modules 3, as can be seen from the arrangement of the first enclosure members 5 mentioned above and in conjunction with Figure 5, the top of these first enclosure members 5 abuts against the top wall of the housing 1, and the bottom of the first enclosure member 5 abuts against the battery module 3 or the partition 4 (wherein, Figure 5 illustrates that the bottom of the first enclosure member 5 penetrates the partition 4 and abuts against the top surface of the battery module 3), thereby achieving effective isolation between multiple sub-flues 0010.

[0054] By setting a first enclosure 5 between any two adjacent battery modules 3, the first flue 001 is divided into multiple sub-flues 0010. Each sub-flue 0010 corresponds one-to-one with a battery module 3, and the sub-flues 0010 are isolated from each other and do not communicate with each other. Each sub-flue 0010 collects the cell ejections from its corresponding battery module 3. Thus, when a cell 31 in a battery module 3 experiences thermal runaway, its ejections enter the connected sub-flue 0010 and do not spread to other sub-flues 0010, thereby preventing other battery modules 3 from being adversely affected by the ejections.

[0055] Regarding the aforementioned scheme of setting a first enclosure 5 between any two adjacent battery modules 3, as shown in Figure 5, multiple separators 4 can be configured, each corresponding to one of the multiple battery modules 3. Each separator 4 covers the top surface of its corresponding battery module 3. The first enclosure 5, positioned between two adjacent battery modules 3, seals through the gap between the two adjacent separators 4, and the bottom end of the first enclosure 5 abuts against the top surface of the cell casing below the separator 4. For example, when setting a first enclosure 5 between adjacent battery modules A and B, the bottom end of the first enclosure 5 can simultaneously abut against a portion of the top surface of the cell 31 in battery module A and a portion of the top surface of the cell 31 in battery module B.

[0056] The above description provides an example of how the first enclosure 5 forms the first flue 001 in the battery pack. In conjunction with any of the battery packs mentioned above, the structure of the first enclosure 5 and its assembly method are described below as an example.

[0057] In this embodiment, the first enclosure member 5 can be a rigid structure, a flexible structure, or a combination of both. The rigidity of the first enclosure member 5 improves its strength, hardness, and service life, and further enhances its high-temperature resistance. The flexibility of the first enclosure member 5 improves its cushioning properties, which is more beneficial for sealing at connection points and for assembly error tolerance. The structural form of the first enclosure member 5 can be selected according to actual needs.

[0058] The following is an exemplary description of the first enclosure member 5 as a structural member combining rigid and flexible structures. As shown in Figure 6, the first enclosure member 5 has a first elastic member 502 and a second elastic member 503 at its two ends respectively; the first elastic member 502 abuts against the top wall of the housing 1, and the second elastic member 503 abuts against the partition 4 or the battery module 3.

[0059] The first enclosure 5 uses a first elastic element 502 and a second elastic element 503 to abut against the top wall 110 of the housing 1 and the battery module 3. The flexibility of the first elastic element 502 and the second elastic element 503 facilitates the interference fit between the first enclosure 5 and other components, thereby improving the connection strength and the sealing performance at the connection point, significantly enhancing the sealing effect of the first flue 001, and ensuring that the flue gas does not overflow from the connection point. In addition, when the distance between the top of multiple battery modules 3 and the top wall 110 is inconsistent, the first elastic element 502 and the second elastic element 503, based on their deformation characteristics, can more easily adapt to the above situation while ensuring the sealing effect at each connection point, thus improving the assembly error tolerance.

[0060] Figure 6 illustrates that the first enclosure member 5 includes: a rigid baffle 501, a first elastic member 502 and a second elastic member 503 respectively connected to the two ends of the rigid baffle 501.

[0061] The first enclosure member 5 is based on a rigid baffle 501 to ensure the strength and hardness of its overall structure, and the rigid baffle 501 typically has stronger high-temperature resistance. In this embodiment, by making the rigid baffle 501 serve as the main body of the first enclosure member 5, and the first elastic member 502 and the second elastic member 503 serve as the abutment ends of the first enclosure member 5 respectively, the first enclosure member 5 possesses excellent strength, hardness, high-temperature resistance, assembly sealing, and high assembly error tolerance.

[0062] For example, the first enclosure member 5 includes a main body and a first end and a second end connected to both ends of the main body. The main body of the first enclosure member 5 includes the aforementioned rigid baffle 501. The first end of the first enclosure member 5 includes at least the aforementioned first elastic member 502, and the second end includes at least the aforementioned second elastic member 503. Further, the first end of the first enclosure member 5 includes the end regions of both the aforementioned first elastic member 502 and the rigid baffle 501, and the second end of the first enclosure member 5 includes the end regions of both the aforementioned second elastic member 503 and the rigid baffle 501. The rigid baffle 501 supports the elastic members at the ends of the first enclosure member 5, which further improves the assembly effect of the first enclosure member 5.

[0063] In this embodiment, along the direction perpendicular to the top wall 110 of the housing 1 (i.e., the up-down direction in FIG. 6), the dimensions of the first elastic member 502 and the second elastic member 503 can be the same or different. For example, one of the first elastic member 502 and the second elastic member 503 can be made larger, thereby further improving the assembly error tolerance.

[0064] Figure 6 illustrates that, along the direction perpendicular to the top wall 110, the size of the first elastic member 502 is larger than the size of the second elastic member 503. This means that when the larger first elastic member 502 abuts against the top wall 110, it is more adaptable to the unevenness of the top wall 110 of the housing 1. Of course, it is not excluded that the size of the first elastic member 502 is equal to the size of the second elastic member 503, or that the size of the first elastic member 502 is smaller than the size of the second elastic member 503.

[0065] The first enclosure member 5 is made entirely of an insulating material, which has at least the characteristics of high temperature resistance, chemical corrosion resistance (e.g., electrolyte resistance), high voltage resistance, and high strength. For example, the rigid baffle 501 of the first enclosure member 5 can be made of a non-metallic rigid insulating sheet, or more specifically, it can be made of a pultruded sheet to ensure at least high strength and hardness.

[0066] In some examples, the rigid baffle 501 of the first enclosure 5 includes a resin matrix and reinforcing fibers distributed inside the resin matrix. The reinforcing fibers may be continuous fibers, which helps to significantly improve the strength and high temperature resistance of the rigid baffle 501 and also helps to reduce the weight of the rigid baffle 501.

[0067] The first elastic element 502 and the second elastic element 503 of the first enclosure 5 can be made of the same or different materials. For example, both can be made of flexible insulating materials such as foam, which have the advantages of being lightweight in addition to having good flexibility and flame retardant properties.

[0068] As mentioned above, one of the first elastic member 502 and the second elastic member 503 abuts against the top wall 110, and the other abuts against the partition 4 or the battery module 3. The "abutment" mentioned above can be direct contact without connection, or it can be connected. Of course, in the case of connection, it is more conducive to improving the assembly effect.

[0069] At least one of the first elastic element 502 and the second elastic element 503 may have an adhesive layer; for example, both the first elastic element 502 and the second elastic element 503 may have an adhesive layer. In this way, both the first elastic element 502 and the second elastic element 503 can be connected to the rigid baffle 501 through the adhesive layer. The first elastic element 502 can also be connected to the top wall 110 of the housing 1 through the adhesive layer, and the second elastic element 503 can also be connected to the separator 4 or the battery module 3 through the adhesive layer. This not only improves assembly stability but also enhances the sealing effect at the connection points.

[0070] The rigidity and flexibility characteristics of the first enclosure member 5 have been described above. The structural form of the first enclosure member 5 will be described below by way of example.

[0071] In this embodiment, the first enclosure member 5 functions as a partition wall. One example is that the first enclosure member 5 can be a partition of uniform thickness (the thickness referred to here is the dimension along the direction parallel to the top wall 110 of the housing 1, i.e., the left-right direction shown in Figure 7). For example, the first enclosure member 5 is a rectangular plate of uniform thickness. Another example is that the first enclosure member 5 can be a partition of variable thickness, meaning the thickness of the first enclosure member 5 is variable along the direction parallel to the top wall 110 of the housing 1.

[0072] Figure 7 illustrates a first enclosure member 5 with variable thickness. As shown in Figure 7, the first enclosure member 5 includes a first blocking section 51, a second blocking section 52, and a third blocking section 53 distributed sequentially. One of the first blocking section 51 and the third blocking section 53 abuts against the top wall 110, and the other abuts against the partition 4 or the battery module 3. The cross-sectional area of ​​the second blocking section 52 is smaller than the cross-sectional areas of the first blocking section 51 and the third blocking section 53, wherein the cross-sectional area is the area of ​​the cross-section parallel to the top wall 110 of the housing 1.

[0073] By designing the cross-sectional areas of the first barrier section 51 and the third barrier section 53 to be larger, it is beneficial to increase the contact area between the first enclosure 5 and the top wall 110 of the housing 1 and the battery module 3 (or separator 4), thereby improving connection stability and sealing effect at the connection position. On the other hand, the second barrier section 52 is designed to be smaller, which is beneficial to reducing the volume and weight of the first enclosure 5 and facilitating its lightweight design.

[0074] Based on the above-described structural arrangement of the first enclosure member 5, an exemplary structure of the first enclosure member 5 can be an I-beam shape, which is convenient for molding and preparation, reducing the difficulty and cost of preparation. Of course, it is not excluded that the first enclosure member 5 can also be other structural forms, such as a Z-shape.

[0075] Figure 7 illustrates that the second barrier segment 52 is a rigid structure. Both the first barrier segment 51 and the third barrier segment 53 include a rigid support portion and a flexible abutment portion. The flexible abutment portion refers to the first elastic element 502 and the second elastic element 503 mentioned above, which are supported by the rigid support portion, making the structure of the first barrier segment 51 and the third barrier segment 53 more stable. The rigid support portions of the first barrier segment 51 and the third barrier segment 53 are also respectively connected to the corresponding ends of the second barrier segment 52. For example, the rigid support portions of the first barrier segment 51 and the third barrier segment 53 are integrally formed and connected to the second barrier segment 52.

[0076] As shown in Figures 8 and 9, the partition 4 has multiple valve opening structures 40 corresponding to the multiple battery cells 31. The valve opening structures 40 can be quickly opened by the impact of the battery cell ejection material, allowing the battery cell ejection material, including flue gas, to be introduced from the battery cell 31 into the first flue 001. The multiple valve opening structures 40 include at least one of a tear line 401 and a valve plate 402; the tear line 401 includes multiple spaced through holes; the valve plate 402 has grooves or through holes.

[0077] In some examples, as shown in Figure 8, the valve opening structure 40 is a tear line 401, wherein the tear line 401 includes a plurality of spaced through holes. By setting a plurality of spaced through holes on the partition 4, the air pressure balance on both sides of the partition 4 is maintained on the one hand, and the tear line 401 is facilitated to break easily and quickly on the other hand.

[0078] The shape of the tear line 401 and the shape of the hole forming the tear line 401 can be any geometric shape, as long as the valve opening structure 40 forms a through hole on the partition 4 when it is in the open state.

[0079] For example, the shape of the tear line 401 can be rectangular, circular, elliptical, etc., and some holes for forming the tear line 401 that are easy to form include, but are not limited to, round holes, strip holes, arc-shaped holes, etc. The multiple holes forming the tear line 401 are arranged at intervals, wherein the spacing between any two holes can be the same or different. In order to simplify the preparation process of the tear line 401, the spacing between any two holes can be the same.

[0080] In other examples, as shown in Figure 9, the valve opening structure 40 is a valve plate 402, which has grooves or through holes (Figure 9 illustrates that the upper row of valve plates 402 has through holes to balance the air pressure on both sides of the valve plate 402; the lower row of valve plates 402 has grooves to facilitate rapid breakage of the valve plate 402 under impact). The valve plate 402 is thin, and the grooves or through holes on it can be broken and opened under the impact of the battery cell ejection material, thereby releasing the battery cell ejection material.

[0081] The valve opening structure 40 can be integrally formed on the partition 4. For example, multiple valve opening structures 40 can be formed on the partition 4 through processes such as stamping and cutting. Alternatively, the valve opening structure 40 can also be connected to the partition 4 through subsequent assembly processes. For example, if the partition 4 has multiple openings, the valve opening structure 40 can be assembled by connecting it to the partition 4 and covering the corresponding openings. For example, this connection method can be adhesive bonding.

[0082] In this embodiment, the insulating material used for the partition 4 has at least the characteristics of impact resistance, high temperature resistance, chemical corrosion resistance (e.g., electrolyte resistance), and high pressure resistance. For example, the partition 4 can be prepared using a ceramic composite tape with excellent fire resistance. The ceramic composite tape also has the advantages of being easy to stamp and cut, and the valve opening structure 40 can be easily formed on it in one step, reducing material redundancy.

[0083] For example, the partition 4 is a ceramic composite strip, and the multiple valve opening structures 40 on the ceramic composite strip are tear lines 401. In this way, tear lines 401 can be easily formed on the ceramic composite strip through processes such as stamping and cutting. While ensuring excellent insulation and isolation performance, it also helps to reduce the difficulty and cost of preparation.

[0084] Since the separator 4 and the first enclosure 5 have excellent high temperature resistance, chemical corrosion resistance and impact resistance, it can be seen that by setting the separator 4 and the first enclosure 5, the requirements of various components in the battery pack for electrolyte and high temperature resistance are also reduced accordingly. For example, the requirements for electrolyte resistance and high temperature resistance of various components such as cell insulating varnish, cold plate insulating varnish, electrical compartment, and aluminum busbar insulating parts are reduced, which also helps to reduce the cost of the battery pack.

[0085] In conjunction with any of the battery packs mentioned above, the following further elaborates on the manner in which the first enclosure 5 forms the first flue 001 and its outlet 0011.

[0086] In some examples, as shown in Figures 1-2, the first enclosure 5 is arranged around a portion of the peripheral area of ​​the top surface of the battery module 3 facing the top wall 110, and the gap between the two ends of the first enclosure 5 distributed circumferentially serves as the outlet 0011 of the first flue 001. Further, the outlet 0011 of the first flue 001 can be arranged adjacent to the explosion-proof valve 2.

[0087] Taking a square battery pack as an example, the battery module 3 is rectangular in shape, including a first side, a second side, a third side, and a fourth side connected end to end. The first side of the battery module 3 is adjacent to the explosion-proof valve 2. The first enclosure 5 can be arranged around the second side, the third side, and the fourth side of the top surface of the battery module 3. The first enclosure 5 is not arranged on the first side of the top surface of the battery module 3, or the first enclosure 5 is arranged in a part of the first side of the top surface of the battery module 3. In this way, the outlet 0011 of the first flue 001 is formed on the first side of the top surface of the battery module 3. Furthermore, the outlet 0011 of the first flue 001 can be adjacent to the explosion-proof valve 2, that is, the outlet 0011 of the first flue 001 faces the explosion-proof valve 2.

[0088] In this way, the battery cell ejection material in the first flue 001 can be quickly and directly discharged to the explosion-proof valve 2 from the outlet 0011 of the first flue 001. The battery cell ejection material only travels through the first side area of ​​the battery module 3, and it is almost impossible for it to spread to other side areas of the battery module 3. This prevents the battery cell ejection material from falling into the cold plate assembly 8 and the high-voltage electrical compartment 9 at the bottom of the battery pack from the second, third, and fourth sides of the battery module 3. This is because, for a square battery pack, the high-voltage electrical compartment 9 is usually located on the third side of the battery module 3 (see Figure 4). The high-voltage electrical compartment 9 is opposite to the explosion-proof valve 2, that is, the high-voltage electrical compartment 9 is opposite to the outlet 0011 of the first flue 001.

[0089] Further, as shown in Figures 10 and 11, the battery pack provided in this embodiment of the application also includes a second enclosure 6, which is located between the first sidewall of the battery module 3 and the first sidewall of the housing 1 to form a second flue 002 between the first sidewall of the battery module 3 and the first sidewall of the housing 1. The first sidewall of the housing 1 is provided with an explosion-proof valve 2, and the first sidewall of the battery module 3 faces the first sidewall of the housing 1. The outlet 0011 of the first flue 001, the second flue 002, and the explosion-proof valve 2 are sequentially connected, and the projection of the explosion-proof valve 2 on the first sidewall of the battery module 3 is located within the second flue 002.

[0090] It should be noted that the projection of the explosion-proof valve 2 on the battery module 3 is located within the second flue 002. For example, the dotted line a in Figure 11 is the projection of the explosion-proof valve 2 on the battery module 3, thereby ensuring reliable communication between the second flue 002 and the explosion-proof valve 2.

[0091] Taking the square battery pack as an example, as mentioned above, the outlet 0011 of the first flue 001 is located on the first side of the top surface of the battery module 3. When the battery cell ejection material is transferred from here to the explosion-proof valve 2, some of the battery cell ejection material may fall into the cavity between the first side of the battery module 3 and the housing 1 under the action of gravity, and then spread to the part of the cold plate assembly 8 exposed in the cavity.

[0092] To avoid the aforementioned technical problems, a second enclosure 6 is provided between the first sidewall of the battery module 3 facing the explosion-proof valve 2 and the corresponding sidewall of the housing 1 to form a second flue 002. The second flue 002 is isolated from the cold plate assembly 8, thereby preventing the cell ejection material from spreading to the cold plate assembly 8 exposed in that area.

[0093] One end of the second enclosure 6 can be connected to the first side wall of the battery module 3, and the other end abuts against the first side wall of the housing 1.

[0094] As shown in Figure 11, the second enclosure 6 is connected to the first sidewall of the battery module 3, which facilitates precise positioning of the second enclosure 6. The second enclosure 6 is located at both ends of the first sidewall of the battery module 3 along the second direction, and at the bottom end of the first sidewall of the battery module 3. That is, the second enclosure 6 is provided at the lower end, front end, and rear end of the first sidewall of the battery module 3, thereby isolating the portion of the cold plate assembly 8 located on the first side of the battery module 3 from the outside of the second flue 002.

[0095] The ejected material from the battery cell is discharged to the outside of the battery pack through the outlet 0011 of the first flue 001, the second flue 002, and the explosion-proof valve 2 in sequence. This ensures that the ejected material from the battery cell is discharged to the outside of the battery pack through the explosion-proof valve 2, so as to avoid affecting other battery cells 31, cold plate assembly 8, and electrical components inside the high-voltage electrical compartment 9.

[0096] The material and structural arrangement of the second enclosure component 6 can be the same as those of the first enclosure component 5. The relevant schemes of the first enclosure component 5 mentioned above can be referred to, and will not be repeated here.

[0097] In other examples, as shown in Figure 12, the first enclosure 5 is arranged to surround the entire peripheral area of ​​the top surface of the battery module 3, and the side of the first enclosure 5 adjacent to the explosion-proof valve 2 has an opening, which serves as the outlet 0011 of the first flue 001.

[0098] By providing an opening on the side of the first enclosure 5 adjacent to the explosion-proof valve 2 as the outlet 0011 of the first flue 001, the outlet 0011 of the first flue 001 is arranged adjacent to the explosion-proof valve 2, which also allows the battery cell ejected material to be quickly introduced into the explosion-proof valve 2.

[0099] Furthermore, as shown in Figure 13, the battery pack may also include a flow guide pipe 7, one end of which is connected to the outlet 0011 of the first flue 001, and the other end of which is connected to the explosion-proof valve 2.

[0100] By further setting the flow guide pipe 7, the first flue 001 and the inner cavity of the flow guide pipe 7 form a closed flue, ensuring that all the battery cell ejection material is discharged to the outside of the battery pack through the explosion-proof valve 2. At the same time, it also prevents some battery cell ejection material from falling into the cavity between the first side of the battery module 3 and the shell 1 under the action of gravity, and then spreading to the part of the cold plate assembly 8 exposed in the cavity.

[0101] In this embodiment, the number of explosion-proof valves 2 can be set to one, or it can be adapted to the number of battery modules 3. For example, the number of explosion-proof valves 2 can also be set to multiple. When the number of explosion-proof valves 2 is set to multiple, the flow guide pipe 7 can be designed as a multi-port pipe accordingly.

[0102] Any of the battery packs mentioned above in the embodiments of this application can be applied to various scenarios such as power plants, data centers, and vehicles.

[0103] On the other hand, embodiments of this application also provide an energy storage system, which includes: a power converter and at least one battery pack as described above; wherein, the power converter is used to convert the voltage output from the battery pack into power and output it to the power grid or a load, and / or to convert the voltage output from an external power source into power and output it to the battery pack.

[0104] The energy storage system provided in this application embodiment has all the advantages of the battery pack provided in this application embodiment, and will not be repeated here.

[0105] The above description is only for the purpose of enabling those skilled in the art to understand the technical solution of this application, and is not intended to limit this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A battery pack, wherein, The battery pack includes a housing (1) and a battery module (3). The housing (1) is used to house the battery module (3). The battery module (3) includes a plurality of cells (31) arranged along a first direction. A partition (4) and a first enclosure (5) are provided between the top surface of the battery module (3) and the top wall of the housing (1). The partition (4) covers the top surface of the battery module (3). One end of the first enclosure (5) abuts against the top wall of the housing (1), and the other end of the first enclosure (5) abuts against the battery module (3) or the partition (4). The first enclosure (5) surrounds the periphery of the top surface of the battery module (3). The partition (4), the top wall of the shell (1) and the first enclosure (5) form a first flue (001), the first flue (001) is provided with an outlet (0011), and an explosion-proof valve (2) is provided on the side wall of the shell (1), the explosion-proof valve (2) is connected to the outlet (0011) of the first flue (001); Each of the multiple battery cells (31) is provided with a pressure relief valve (310), and the partition (4) includes multiple valve opening structures (40), which are respectively arranged opposite to the pressure relief valves (310) of the multiple battery cells (31).

2. The battery pack according to claim 1, wherein, Multiple battery modules (3) are arranged side by side along a second direction, wherein the second direction is perpendicular to the first direction; The first enclosure (5) is also disposed between any two adjacent battery modules (3) to divide the first flue (001) into a plurality of mutually isolated sub-flues (0010), and the sub-flues (0010) correspond one-to-one with the battery modules (3).

3. The battery pack according to claim 1, wherein, The first enclosure member (5) has a first elastic member (502) and a second elastic member (503) at its two ends respectively; The first elastic member (502) abuts against the top wall of the housing (1), and the second elastic member (503) abuts against the partition (4) or the battery module (3).

4. The battery pack according to claim 3, wherein, The first enclosure member (5) includes a rigid baffle (501), and the first elastic member (502) and the second elastic member (503) are respectively connected to the two ends of the rigid baffle (501).

5. The battery pack according to claim 1, wherein, The first enclosure member (5) includes a first barrier section (51), a second barrier section (52) and a third barrier section (53) distributed sequentially along a direction perpendicular to the top wall of the housing (1), wherein one of the first barrier section (51) and the third barrier section (53) abuts against the top wall of the housing (1) and the other abuts against the battery module (3) or the partition (4); The cross-sectional area of ​​the second barrier segment (52) is smaller than that of the first barrier segment (51) and the third barrier segment (53), wherein the cross-sectional area is the area of ​​the cross-section parallel to the top wall of the housing (1).

6. The battery pack according to claim 5, wherein, The first enclosure component (5) is I-shaped.

7. The battery pack according to claim 1, wherein, The plurality of valve opening structures (40) include at least one of a tear line (401) and a valve plate (402); The tear line (401) includes a plurality of spaced through holes; The valve plate (402) has grooves or through holes.

8. The battery pack according to claim 7, wherein, The partition (4) is a ceramic composite strip, and the multiple valve opening structures (40) are tear lines (401).

9. The battery pack according to any one of claims 1-8, wherein, The first enclosure (5) is arranged around a portion of the peripheral area of ​​the top surface of the battery module (3), and the gap between the two ends of the first enclosure (5) distributed circumferentially serves as the outlet (0011) of the first flue (001).

10. The battery pack according to claim 9, wherein, The battery pack also includes a second enclosure (6), which is located between the first side wall of the battery module (3) and the first side wall of the housing (1) to form a second flue (002) between the first side wall of the battery module (3) and the first side wall of the housing (1). The explosion-proof valve (2) is provided on the first side wall of the housing (1), and the first side wall of the battery module (3) faces the first side wall of the housing (1). The outlet (0011) of the first flue (001), the second flue (002), and the explosion-proof valve (2) are connected in sequence, and the projection of the explosion-proof valve (2) on the first side wall of the battery module (3) is located in the second flue (002).

11. The battery pack according to claim 10, wherein, The second enclosure member (6) is connected to the first side wall of the battery module (3), and the second enclosure member (6) is located at both ends of the first side wall of the battery module (3) distributed along the second direction, and at the bottom end of the first side wall of the battery module (3), wherein the second direction is perpendicular to the first direction.

12. The battery pack according to any one of claims 1-8, wherein, The first enclosure (5) is arranged around the entire periphery of the top surface of the battery module (3). The side wall of the first enclosure (5) adjacent to the explosion-proof valve (2) has an opening, which serves as the outlet (0011) of the first flue (001).

13. The battery pack according to claim 12, wherein, The battery pack also includes a flow guide pipe (7), one end of which is connected to the outlet (0011) of the first flue (001), and the other end of which is connected to the explosion-proof valve (2).

14. An energy storage system, wherein, The energy storage system includes: a power converter and at least one battery pack as described in any one of claims 1-13; The power converter is used to convert the voltage output by the battery pack to power and output it to the power grid or load, and / or to convert the voltage output by an external power source to power and output it to the battery pack.

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