Fluid treatment device for a battery pack and battery pack

Abstract

A fluid treatment device for a battery pack includes a housing and a separator assembly. The housing is provided with an inlet for receiving fluid discharged by a battery pack, and further provided with an outlet for discharging final treated fluid. The separator 5 assembly is disposed in the housing and comprises at least one centrifugal separator configured to remove liquid droplets and / or particles from the fluid.

Description

FLUID TREATMENT DEVICE FOR A BATTERY PACK AND BATTERY PACKTECHNICAL FIELD

[0001] Embodiments relate to a battery pack, and more specifically a fluid treatment device for a battery pack.BACKGROUND

[0002] Battery cells are commonly used to store electrical energy for applications such as electric vehicles and stationary energy storage systems. The chemistry of rechargeable battery cells, as well as external factors, can cause these cells to generate significant thermal energy. Prolonged exposure to elevated temperatures may lead to a thermal event in the battery cell. Battery cells are typically arranged in series or parallel to form a battery module or battery pack.

[0003] With the increasing adoption of electric vehicles and the trend toward higher energy density and longer service life of battery packs, incidents of battery thermal runaway have become more frequent. During a thermal runaway event, battery packs can emit large quantities of toxic and harmful gases, posing risks to passengers, bystanders, and the environment. If the vehicle’s air conditioning system is operating, these harmful gases may be drawn into the passenger compartment, causing discomfort or health hazards and potentially impairing the occupants’ ability to evacuate the vehicle safely.

[0004] Furthermore, the gases released during thermal runaway events often contain solid particles and liquid droplets. The high pressure of these gases makes it challenging to filter out such contaminants; excessive gas pressure can damage filtration devices and may even cause the battery pack to rupture.

[0005] Therefore, there is a need to develop a fluid treatment device for battery packs that can reliably remove contaminants from the discharge during a thermal runaway event.SUMMARY

[0006] An object of the present disclosure is to provide a fluid treatment device for a battery pack that can reliably remove contaminants from the fluid that is discharged by battery cells during a thermal runaway event.

[0007] In one aspect, a fluid treatment device for a battery pack is provided. The fluidtreatment device may comprise a housing and a separator assembly. The housing may be provided with an inlet for receiving fluid discharged by the battery pack and may be further provided with an outlet for discharging treated fluid. The separator assembly may be disposed in the housing. The separator assembly may include at least one centrifugal separator. The at least one centrifugal separator may be configured to remove at least one of liquid droplets and particles from the fluid. When the liquid droplets and / or particles from the fluid are removed, the exhaust passage of the battery pack is less likely to be clogged up, thereby allowing the gas in the fluid to exit the battery pack quickly, releasing the high pressure in the battery pack during a thermal runaway event.

[0008] In another aspect, a battery pack is provided. The battery pack may include at least one battery cell, a degassing device and the fluid treatment device as described above. The fluid treatment device may be in fluid communication with an exhaust opening of the degassing device. The fluid treatment device may remove contaminants from the fluid that flows out of the exhaust opening.

[0009] Other features, advantages and embodiments of the present disclosure will become apparent from the detailed description, the claims and the drawings. The detailed description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the disclosure.BRIEF DESCRIPTION OF DRAWINGS

[0010] The present disclosure will become more fully understood from the detailed description and the accompanying drawings.

[0011] FIG. 1 is a schematic exploded perspective view of a fluid treatment device according to embodiments.

[0012] FIG. 2 is a schematic sectional view of a fluid treatment device according to embodiments, showing section lines B-B, C-C, D-D, E-E, and F-F.

[0013] FIG. 3 is a schematic sectional view of the fluid treatment device of FIG. 2 taken along section line B-B, showing details of a part of a first filter element of a coarse filter assembly.

[0014] FIG. 4 is a schematic sectional view of the fluid treatment device of FIG. 2 taken along section line C-C, showing details of a separator assembly.

[0015] FIG. 5 is a schematic sectional view of the fluid treatment device of FIG. 2 takenalong section line D-D, showing details of a part of a second filter element of the coarse filter assembly.

[0016] FIG. 6 is a schematic sectional view of the fluid treatment device of FIG. 2 taken along section line E-E, showing details of a part of a fine filter assembly.

[0017] FIG. 7 is a schematic sectional view of the fluid treatment device of FIG. 2 taken along section line F-F, showing layout of the coarse filter assembly, the separator assembly and the fine filter assembly.DESCRIPTION OF EMBODIMENTS

[0018] The following description is merely exemplary in nature and is not intended to limit the present disclosure, application, or uses. It should be understood that throughout the drawings, corresponding reference numerals indicate like or corresponding parts and features. Additionally, the drawings are generally schematic and not necessarily to scale. Some features may be exaggerated or minimized to show details of particular components. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art to variously employ the present disclosure.

[0019] Certain terminology may be used in the following description for the purpose of reference only, and thus are not intended to be limiting. For example, terms such as “above” and “below” refer to directions in the drawings to which reference is made. Terms such as “front”, “back”, “fore”, “aft”, “left”, “right”, “rear”, “side”, “upward”, “downward”, “horizontal”, “vertical”, “top”, and “bottom”, etc., describe the orientation and / or location of portions of the components or elements within a consistent but arbitrary frame of reference, which is made clear by reference to the text and the associated drawings describing the components or elements under discussion.

[0020] Furthermore, terms such as “first”, “second”, “third”, and so on may be used to describe separate components. Such terminologies are used descriptively for the figures, and do not represent limitations on the scope of the disclosure, as defined by the appended claims. As used herein, the term “downstream” or "upstream" may be used to indicate a direction with regard to a fluid flow direction.

[0021] During a thermal runaway of battery cells, the battery cells may discharge a large amount of fluid within a short period of time. The discharged fluid may include a mixtureof gases. The fluid may also include liquid droplets, for example, liquid electrolyte, as well as solid particles.

[0022] Referring now to the drawings, wherein like reference numbers refer to like features throughout the several views.

[0023] FIG. 1 is a schematic exploded perspective view of a fluid treatment device 100 according to embodiments.

[0024] FIG. 2 is a schematic sectional view of the fluid treatment device 100 according to embodiments, showing section lines B-B, C-C, D-D, E-E, and F-F.

[0025] According to one example, a fluid treatment device 100 for a battery pack is provided. According to one example, the fluid treatment device 100 may comprise a housing 10. The housing 10 may be provided with an inlet for receiving fluid 20 discharged during thermal runaway event of the battery pack, and an outlet 5 for discharging treated fluid 23, also referred herein as final filtered fluid 23.

[0026] According to one example, the fluid treatment device 100 may further comprise a separator assembly 3. The separator assembly 3 may be disposed in the housing 10 and may be configured to centrifugally filter out liquid contents and particles in the fluid 20 to generate secondary filtered fluid 22.

[0027] According to one example, the fluid treatment device 100 may further comprise a fine filter assembly 4. The fine filter assembly 4 may be disposed in the housing 10 downstream of the separator assembly 3 and may be configured to filter out remaining particles from the secondary filtered fluid 22 and to remove harmful gas, to generate the treated fluid 23. The fine filter assembly 4 may prevent harmful gas from entering the surrounding environment, thereby preventing pollution of the environment and protecting the health of humans in the environment.

[0028] According to one example, the fluid treatment device 100 may further comprise a coarse filter assembly 2. The coarse filter assembly 2 may be disposed in the housing 10 adjacent to the inlet 1 and may be configured to filter out relatively large particles from the fluid to generate primary filtered fluid 21. The coarse filter assembly 2 may be disposed upstream of the separator assembly 3. The separator assembly 3 may remove liquid droplets and / or particles in the primary filtered fluid 21 to generate the secondary filtered fluid 22. The coarse filter assembly 2 may prevent large particles from causing blockage in the separator assembly 3 which may impede the performance of the separator assembly 3.

[0029] As understood by those skilled in the art, the fluid treatment device 100 may further comprise any other suitable components, such as a controller and / or sensors, without departing the scope of the disclosure.

[0030] According to one example, the coarse filter assembly 2 may comprise a first filter element 2.1 and a second filter element 2.2 disposed downstream of the first filter element 2.1. The first filter element 2.1 includes first meshes 2.1.1 with a first mesh size and the second filter element 2.2 includes second meshes 2.2.1 with a second mesh size, the second mesh size may be less than the first mesh size. As understood by those skilled in the art, the coarse filter assembly 2 may comprise any other suitable number of filter elements, such as 3, 4, etc., without departing from the scope of the disclosure.

[0031] According to one example, the first filter element 2.1 and the second filter element 2.2 may include filter screens. As understood by those skilled in the art, the first filter element 2.1 and the second filter element 2.2 may be any other suitable type of filter elements, such as pleated filter bellows, without departing the scope of the disclosure.

[0032] By means of the multi-stage filtration of the fluid treatment device 100, particles of different sizes, liquid and / or harmful gas can be reliably filtered out or sorbed, and the larger particles can be intercepted in the coarse filter assembly 2 of the fluid treatment device to prevent from blocking the fine filter assembly 4, resulting in unobstructed exhaust fluid flow during thermal runaway event, and then avoiding explosion of the battery pack.

[0033] FIG. 3 is a schematic sectional view of the fluid treatment device of FIG. 2 taken along section line B-B, showing details of a part of a first filter element 2.1 of a coarse filter assembly 2. FIG. 5 is a schematic sectional view of the fluid treatment device of FIG. 2 taken along section line D-D, showing details of a part of a second filter element 2.2 of the coarse filter assembly 2.

[0034] According to one example, the first meshes 2.1.1 of the first filter element 2.1 may be elongated shaped, such as rectangular, oval. As understood by those skilled in the art, the first meshes 2.1.1 of the first filter element 2.1 may be of any other suitable shape, such as circular, square, etc., without departing the scope of the disclosure. According to one example, the second meshes 2.2.1 of the second filter element 2.2 may be square. As understood by those skilled in the art, the second meshes 2.2.1 of the second filter element 2.2 may be of any other suitable shape, such as circular, rectangular, etc., without departing the scope of the disclosure.

[0035] By means of the fluid treatment device, the number, area, and mesh size of the filter screens in the coarse filter assembly 2 can be flexibly adjusted according to the different volume of exhaust fluid caused by the type of different battery packs, the quantity, nature, and size of the particles contained in the exhaust fluid 20.

[0036] FIG. 4 is a schematic sectional view of the fluid treatment device of FIG. 2 taken along section line C-C, showing details of a separator assembly 3. According to one example, the separator assembly 3 may comprise at least one centrifugal separator. Each centrifugal separator may comprise a centrifugal accelerating body 3.2 with an upper opening 3.5 and a cap plate 3.4 for closing the upper opening 3.5. The centrifugal accelerating body 3.2 may be provided with an inlet hole 3.1 tangentially extending through side wall of the centrifugal accelerating body 3.2. The cap plate 3.4 may be provided with an outlet opening 3.3.

[0037] According to one example, the centrifugal accelerating body 3.2 may be of an at least substantially cylindrical shape with a tapered bottom end. The tapered bottom end may be configured to collect separated liquid contents and / or particles. As understood by those skilled in the art, the centrifugal accelerating body 3.2 may be of any other suitable shape, without departing the scope of the disclosure.

[0038] According to one example, the separator assembly 3 may comprise a plurality of centrifugal separators disposed in series. According to one example, the plurality of centrifugal separators may comprise three centrifugal separators. As understood by those skilled in the art, the plurality of centrifugal separators may comprise any other suitable number of centrifugal separators , such as 2, 4, 5, etc., without departing from the scope of the disclosure.

[0039] By means of the separator assembly 3, solid particles or liquid contents contained in the fluid 20 discharged during thermal runaway event can be reliably filtered out. This may prevent the blockage of the fine filter assembly 4, thereby allowing the fine filter assembly to perform its function.

[0040] FIG. 6 is a schematic sectional view of the fluid treatment device of FIG. 2 taken along section line E-E, showing details of a part of a fine filter assembly 4. According to one example, the fine filter assembly 4 may comprise at least one filter bellows. The at least one filter bellows may have a pleated filter medium. The pleated filter medium may include a sorbent for sorbing harmful gas. The sorbent may include at least one ofadsorbent, chemisorbent, and catalytic media.

[0041] In an embodiment, the sorbent may include activated carbon.

[0042] As understood by those skilled in the art, the fine filter assembly 4 may comprise any other suitable type of filter devices, without departing the scope of the disclosure. In addition, the fine filter assembly 4 may comprise any suitable number of filter devices, without departing the scope of the disclosure.

[0043] By means of the fine filter assembly 4, harmful gases contained in the gas discharged during thermal runaway event can be reliably removed, thus ensuring safety of the passenger in an electric vehicle where the battery cells are in a thermal runaway event.

[0044] FIG. 7 is a schematic sectional view of the fluid treatment device 100 of FIG. 2 taken along section line F-F, showing layout of the coarse filter assembly 2, the separator assembly 3 and the fine filter assembly 4. According to one example, the housing 10 has a rectangular shape in a horizontal cross-section including a first side 13, an opposite second side 14, a third side 15 extending between the first side 13 and the second side 14, and a fourth side 16 extending between the first side 13 and the second side 14 opposite to the third side 15, a corner at which the first side 13 and the third side 15 intersect with each other may be cut away to form a first rectangular portion 11 and a second rectangular portion 12, width of the first rectangular portion 11 may be less than width of the second rectangular portion 12.

[0045] According to one example, the inlet 1 may be located in the first side 13, the outlet 5 may be located in the third side 15, the coarse filter assembly 2 may be disposed in the first rectangular portion 11, the separator assembly 3 may be at least partly disposed in the first rectangular portion 11, and the fine filter assembly 4 may be disposed in the second rectangular portion 12 adjacent to the third side 15. According to one example, the fine filter assembly 4 may not overlap with the coarse filter assembly 2 and the separator assembly 3, when seen in an inflow direction of the fluid 20.

[0046] A battery pack is also provided. The battery pack may include at least one battery cell, a degassing device, and a fluid treatment device 100. The fluid treatment device 100 may be disposed in an exhaust passage of the degassing device. The degassing device may also be known as a battery venting unit to a person skilled in the art. The degassing device may be configured to release fluid discharged by the at least one battery cell out of the battery pack when the pressure in the battery pack reaches a predefined threshold. The fluidtreatment device 100 may remove contaminants, such as harmful gas, electrolyte droplets and solid particles, from the fluid before the fluid is released into the environment.

[0047] By means of layout of the coarse filter assembly 2, the separator assembly 3 and the fine filter assembly 4, the exhaust gas flow in higher velocity will directly flow into the coarse filter assembly 2 and the separator assembly 3, thus facilitating the centrifugal separation of the separator assembly 3. In contrast, the exhaust fluid flow in higher velocity will not directly impinge on the fine filter assembly 4, instead, it will change in direction and slow in velocity before entering the fine filter assembly 4, thus protecting the fine filter assembly 4 for finer filtration.

[0048] Now, operation of the fluid treatment device 100 is described. Fluid 20 may be discharged from the battery pack during thermal runaway event, and enters the inlet 1. Then, the fluid 20 flows through the coarse filter assembly 2, such as the first filter element 2.1 and the second filter element 2.2. The first filter element 2.1 and the second filter element 2.2 filter out relatively large particles from the fluid 20 to generate primary filtered fluid 21. The primary filtered fluid 21 then flows into separator assembly 3. The primary filtered fluid 21 flows into respective separator assembly via respective inlet hole 3.1, then be accelerated by the centrifugal accelerating body 3.2, thus generating a large centrifugal force on the primary filtered fluid 21. liquid contents and particles remaining in the primary filtered fluid 21 are centrifugally separated, and are collected in the bottom of the centrifugal accelerating body 3.2. The secondary filtered fluid 22 flows out of the centrifugal accelerating body 3.2 via the outlet opening 3.3. The secondary filtered fluid 22 changes in direction and slows in velocity, and then flows into the fine filter assembly 4. The fine filter assembly 4 filters out remaining particles from the secondary filtered fluid22 and to adsorb harmful gas, to generate the final filtered fluid 23. The final filtered fluid23 may be discharged via outlet 5.

[0049] Aspects of the present disclosure have been described in detail with reference to the illustrated embodiments; those skilled in the art will recognize, however, that many modifications may be made thereto without departing from the scope of the present disclosure. The present disclosure is not limited to the precise construction and compositions disclosed herein; any and all modifications, changes, and variations apparent from the foregoing descriptions are within the scope of the disclosure as defined by the appended claims. Moreover, the present concepts expressly include any and allcombinations and sub-combinations of the preceding elements and features.

Claims

CLAIMS1. A fluid treatment device (100) for a battery pack, comprising: a housing (10) is provided with an inlet (1) for receiving fluid (20) discharged by the battery pack, and further provided with an outlet (5) for discharging treated fluid (23); and a separator assembly (3) disposed in the housing (10), the separator assembly (3) comprising at least one centrifugal separator configured to remove liquid droplets and / or particles from the fluid (20).

2. The fluid treatment device (100) of claim 1, wherein each centrifugal separator of the separator assembly (3) comprises: a centrifugal accelerating body (3.2) with an upper opening (3.5), and a cap plate (3.4) for closing the upper opening (3.5), the cap plate (3.4) provided with an outlet opening (3.3), wherein the centrifugal accelerating body (3.2) is provided with an inlet hole (3.1) tangentially extending through side wall of the centrifugal accelerating body (3.2).

3. The fluid treatment device (100) of claim 2, wherein the centrifugal accelerating body (3.2) has an at least substantially cylindrical shape with a tapered bottom end.

4. The fluid treatment device (100) of any preceding claim, wherein the separator assembly (3) comprises a plurality of centrifugal separators arranged in series.

5. The fluid treatment device (100) of any preceding claim, further comprising: a fine filter assembly (4) disposed in the housing (10) downstream of the separator assembly (3), wherein the fine filter assembly (4) is configured to remove harmful gas from the fluid to generate the final filtered fluid (23), and optionally, further configured to remove remaining particles in the fluid.

6. The fluid treatment device (100) of claim 5, wherein the fine filter assembly (4) comprises a sorbent for sorbing harmful gas.

7. The fluid treatment device (100) of claim 6, wherein the sorbent comprises at least one of adsorbent, chemisorbent and catalytic media.

8. The fluid treatment device (100) of any one of claims 5 to 7, wherein the fine filter assembly (4) comprises at least one filter bellows with a pleated filter medium comprising the sorbent.

9. The fluid treatment device (100) of any one of claims 5 to 8, wherein the fine filter assembly (4) and the separator assembly (3) are laterally offset from each other such that they do not overlap when viewed along an inflow direction of the fluid (20).

10. The fluid treatment device (100) of any preceding claim, further comprising: a coarse filter assembly (2) disposed in the housing (10), the coarse filter assembly (2) configured to intercept large particles in the fluid.

11. The fluid treatment device (100) of claim 10, wherein the coarse filter assembly (2) is disposed adjacent to the inlet (1), upstream of the separator assembly (3).

12. The fluid treatment device (100) of any one of claims 10 to 11, wherein the coarse filter assembly (2) and the separator assembly (3) are laterally offset from each other such that they do not overlap when viewed along an inflow direction of the fluid (20).

13. The fluid treatment device (100) of any one of claims 10 to 12, wherein the coarse filter assembly (2) comprises: a first filter element (2.1), and a second filter element (2.2) disposed downstream of the first filter element (2.1), the first filter element (2.1) including first meshes (2.1.1) with a first mesh size, and the second filter element (2.2) including second meshes (2.2.1) with a second mesh size, wherein the second mesh size is less than the first mesh size.

14. The fluid treatment device (100) of claim 13, wherein at least one of the firstfilter element (2.1) and the second filter element (2.2) comprises a filter screen.

15. The fluid treatment device (100) of any preceding claim, wherein the housing (10) has an at least substantially rectangular horizontal cross-section including a first side (13), an opposite second side (14), a third side (15) extending between the first side (13) and the second side (14), and a fourth side (16) extending between the first side (13) and the second side (14) opposite to the third side (15), wherein a corner at which the first side (13) and the third side (15) intersect with each other is cut away to form a first rectangular portion (11) and a second rectangular portion (12), wherein width of the first rectangular portion (11) is less than width of the second rectangular portion (12), and wherein the inlet (1) is located in the first side (13), and the outlet (5) is located in the third side (15).

16. The fluid treatment device (100) of claim 15, wherein the separator assembly (3) is at least partly disposed in the first rectangular portion (11), and further comprising: a coarse filter assembly (2) disposed in the first rectangular portion (11), and a fine filter assembly (4) disposed in the second rectangular portion (12) adjacent to the third side (15).

17. A battery pack, comprising: at least one battery cell; a degassing device; and the fluid treatment device (100) of any preceding claim, in fluid communication with an exhaust opening of the degassing device.

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