Battery pack and vehicle

Abstract

The utility model discloses a battery pack and a vehicle. The battery pack comprises a shell, a battery cell and a liquid cooling plate, the battery cell is located in the shell, and an anti-explosion valve of the battery cell faces the shell wall part of the shell; the liquid cooling plates are connected with the surfaces, facing the shell wall part, of the battery cells, and the liquid cooling plates are arranged on the two sides of the anti-explosion valve; and the shell, the two liquid cooling plates and the battery cell define an exhaust channel. By optimizing the structure of the battery pack, heat spreading can be effectively inhibited when the battery cell is in thermal runaway.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a battery pack and a vehicle. Background Art

[0002] A battery pack consists of multiple cell assemblies, each of which contains multiple cells. During use, the cells present a risk of thermal runaway. To address this risk and its potential spread, a liquid cooling plate is installed on the cell assemblies within the battery pack. If a cell experiences thermal runaway, the high-temperature fluid ejected from the explosion-proof valve will melt through the liquid cooling plate. The cooling fluid within the liquid cooling plate can then be sprayed onto the runaway cell, cooling it and its adjacent cells to prevent the runaway from spreading.

[0003] In the related art, the flow range of the high-temperature medium ejected after the battery cell thermal runaway is not restricted, and the thermal runaway spreads over a wide range. Utility Model Content

[0004] The purpose of this application is to provide a battery pack and a vehicle, which can effectively suppress the spread of heat when the battery cell thermal runaway occurs by optimizing the structure of the battery pack.

[0005] To solve the above technical problems, an embodiment of the present application provides a battery pack, including a housing, a battery cell and a liquid cooling plate;

[0006] The battery core is located in the shell, and the explosion-proof valve of the battery core faces the shell wall of the shell;

[0007] The liquid cooling plate is connected to the surface of the battery cell facing the shell wall, and the liquid cooling plate is provided on both sides of the explosion-proof valve;

[0008] The housing, the two liquid cooling plates and the battery core form an exhaust channel.

[0009] In one feasible solution, the battery pack further includes a buffer member, which is arranged between the liquid cooling plate and the shell wall portion, and the shell, two buffer members, two liquid cooling plates and the battery cells form the exhaust channel.

[0010] In one feasible solution, the dimension of the buffer member in the second direction is h, the distance in the second direction between the plate surface of the liquid cooling plate facing the shell wall portion and the wall surface of the shell wall portion facing the liquid cooling plate is d, and 0.5≤h / d≤20; the second direction is the normal direction of the face portion;

[0011] And / or, a dimension of the buffer in the third direction is w1, a dimension of the liquid cooling plate in the third direction is w2, 0.1≤w1 / w2≤10; and the third direction is an arrangement direction of the two liquid cooling plates.

[0012] In a feasible solution, within a projection plane parallel to the face portion (2111), the projection of the liquid cooling plate (30) and the projection of the explosion-proof valve (212) do not overlap.

[0013] In a feasible solution, a plurality of battery cells are provided in the shell, the plurality of battery cells are arranged along a first direction, the liquid cooling plate extends along the first direction, and the exhaust channel extends along the first direction; the battery pack includes a plurality of electrical connecting plates, the battery cells are provided with poles on both sides of the explosion-proof valve, and the electrical connecting plates connect the poles of two adjacent battery cells; the liquid cooling plate is bonded to the electrical connecting plates.

[0014] In one feasible solution, the electrical connecting piece includes a first connecting piece portion, a flexible bending piece portion, and a second connecting piece portion connected in sequence, wherein the first connecting piece portion and the second connecting piece portion are respectively used to electrically connect to the poles of two adjacent battery cells, and the flexible bending piece portion is bent toward the direction where the face portion is located;

[0015] The bending depth of the flexible bending piece is a, 0.5mm≤a≤5mm; and / or the dimension of the flexible bending piece in the extending direction of the electrical connection piece is b, 3mm≤b≤30mm.

[0016] In one feasible solution, the distance between the two liquid cooling plates in the third direction is w3, the size of the battery cell in the third direction is w4, and 0.1≤w3 / w4≤0.8;

[0017] And / or, the distance between the face portion of the battery cell and the shell wall portion in the second direction is h1,6mm≤h1≤20mm;

[0018] And / or, the distance between the liquid cooling plate and the explosion-proof valve in the third direction is D, 0mm≤D≤30mm;

[0019] And / or, a distance between a plate surface of the liquid cooling plate facing the face portion and the explosion-proof valve in the second direction is H, 0 mm ≤ H ≤ 20 mm;

[0020] The second direction is the normal direction of the face, and the third direction is the arrangement direction of the two liquid cooling plates.

[0021] In one feasible solution, the wall thickness of the liquid cooling plate is 0.1 mm to 2 mm;

[0022] And / or, the liquid cooling plate is a pipe made of aluminum alloy or thermoplastic;

[0023] and / or, the melting point of the liquid cooling plate is not higher than 500° C.;

[0024] And / or, the liquid cooling plate has a cooling channel, the cooling channel has a cooling medium, and the cooling medium is water, or 50% ethylene glycol coolant, or fluorinated liquid.

[0025] In one feasible solution, the shell wall portion is made of steel, or aluminum alloy, or glass fiber composite material, or carbon fiber composite material;

[0026] And / or, the thickness of the shell wall is 0.2 mm to 8 mm;

[0027] And / or, a fireproof layer is integrated on the wall surface of the shell portion facing the battery core, and the thickness of the fireproof layer is 0.1 mm to 3 mm.

[0028] An embodiment of the present application also provides a vehicle, comprising a battery pack as described in any one of the above items.

[0029] The battery pack provided in the embodiment of the present application can be used in vehicles. The battery pack is provided with liquid cooling plates on both sides of the explosion-proof valve of the battery cell. In this way, when a battery cell experiences thermal runaway, causing the explosion-proof valve to rupture and spray out high-temperature medium, the sprayed high-temperature medium can melt through the liquid cooling plate adjacent to the explosion-proof valve, so that the cooling medium in the liquid cooling plate is sprayed to the battery cell in thermal runaway and its adjacent battery cells for cooling. Due to the obstruction of the liquid cooling plates on both sides of the explosion-proof valve, most or even all of the high-temperature medium will be transmitted along the exhaust channel, which can restrict the transmission range of the high-temperature medium and effectively suppress the occurrence of heat spread. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 An exploded view of a battery pack according to an embodiment of the present application is provided;

[0031] Figure 2 A partial three-dimensional cross-sectional view of a battery pack according to an embodiment of the present application;

[0032] Figure 3 for Figure 2 A partial structural diagram of the structure shown;

[0033] Figure 4 A top view of a battery pack with the upper cover hidden in an embodiment provided in the present application;

[0034] Figure 5 for Figure 1 A schematic structural diagram of the outer shell of the battery pack;

[0035] Figure 6 A partial structural diagram of a cell assembly of a battery pack provided in an embodiment of the present application;

[0036] Figure 7 for Figure 6 Schematic diagram of the structure of the battery cell;

[0037] Figure 8 Schematic diagram of the assembly of the liquid cooling plate and the battery cell assembly in a specific embodiment;

[0038] Figure 9 It is a structural schematic diagram of a battery cell assembly assembled with a liquid cooling plate in a specific embodiment;

[0039] Figure 10 for Figure 6 Schematic diagram of the structure of the CEC connector;

[0040] Figure 11 for Figure 10 A side view of the electrical connection piece shown;

[0041] Figure 12 A partial cross-sectional view of a battery pack in one embodiment provided in the present application.

[0042] Description of reference numerals:

[0043] Housing 10, box body 11, upper cover 12, shell wall 121, first chamber 101, second chamber 102;

[0044] Battery cell assembly 20, battery cell 21, top cover 211, face 2111, explosion-proof valve 212, pole 213, shell 214, electrical connection piece 22, first connection piece portion 221, flexible bending piece portion 222, second connection piece portion 223;

[0045] Liquid cooling plate 30 , buffer 40 , exhaust channel 50 , adhesive layer 60 , manifold 70 . DETAILED DESCRIPTION

[0046] In order to enable those skilled in the art to better understand the present application, the present application is further described in detail below with reference to the accompanying drawings and specific implementation methods.

[0047] The ordinal numbers such as first and second used herein are to distinguish different components of the same name, and do not indicate a specific order or a primary-secondary relationship, etc. The term "plurality" used herein refers to a number of two or greater than two, that is, a number of more than two.

[0048] For ease of understanding and description, this article defines three directions for the battery pack. The first direction x is the length direction of the battery pack, which is also the arrangement direction of multiple battery cells in the battery cell assembly. The second direction z is the height direction of the battery pack. The third direction y is the width direction of the battery pack.

[0049] Please refer to Figures 1 to 4 , Figure 1 This is an exploded view of a battery pack in one embodiment of the present application. Figure 2 This is a partial three-dimensional cross-sectional view of a battery pack according to an embodiment of the present application. Figure 3 for Figure 2 The partial structural diagram of the structure shown, Figure 4 A top view of a battery pack with the upper cover hidden in an embodiment provided in the present application.

[0050] In this embodiment, the battery pack includes a housing 10 , battery cells 21 and a liquid cooling plate 30 .

[0051] The battery cell 21 is located in the housing 10 and is provided with an explosion-proof valve 212 . When the battery cell 21 experiences thermal runaway, the explosion-proof valve 212 will rupture to spray out the high-temperature medium inside the battery cell 21 and release the pressure.

[0052] The explosion-proof valve 212 of the battery cell 21 faces one of the shell walls 121 of the outer shell 10, that is, the explosion-proof valve 212 is arranged on the surface 2111 of the battery cell 21 facing the shell wall 121; the liquid cooling plate 30 is connected to the surface 2111 of the battery cell 21 facing the shell wall 121, and liquid cooling plates 30 are provided on both sides of the explosion-proof valve 212. The outer shell 10, the two liquid cooling plates 30 and the battery cell 21 form an exhaust channel 50.

[0053] With the above solution, when thermal runaway occurs in the battery cell 21, causing the explosion-proof valve 212 to rupture and spray out high-temperature medium, the sprayed high-temperature medium can melt through the liquid cooling plate 30 adjacent to the explosion-proof valve 212, so that the cooling medium in the liquid cooling plate 30 is sprayed onto the battery cell 21 in thermal runaway and its adjacent battery cells 21 to cool them down; blocked by the liquid cooling plates 30 on both sides of the explosion-proof valve 212, most or even all of the high-temperature medium will be transmitted along the exhaust channel 50, which can restrict the transmission range of the high-temperature medium and effectively suppress the occurrence of heat spread.

[0054] In a specific implementation, at least one battery cell assembly 20 is disposed within the battery pack housing 10. The battery cell assembly 20 includes multiple battery cells 21 arranged along a first direction x. The explosion-proof valves 212 of each battery cell 21 in the battery cell assembly 20 are oriented in the same direction, and the surface portions 2111 of each battery cell 21 facing the housing wall 121 form the wall surface of the battery cell assembly 20 facing the housing wall 121.

[0055] The liquid cooling plate 30 extends along the first direction x, that is, the liquid cooling plate 30 extends along the arrangement direction of the multiple battery cells 21 in the battery cell assembly 20, and the liquid cooling plate 30 is connected to the wall surface of the battery cell assembly 20, that is, the liquid cooling plate 30 is connected to the surface 2111 of each battery cell 21 in the battery cell assembly 20 facing the shell wall portion 121.

[0056] In one embodiment, a buffer member 40 is provided between the liquid cooling plate 30 and the housing wall 121. The housing 10, two buffer members 40, two liquid cooling plates 30, and the battery cell 21 form an exhaust passage 50. In this way, when a battery cell 21 experiences thermal runaway, the high-temperature medium ejected from the explosion-proof valve 212 is blocked not only by the liquid cooling plate 30 but also by the buffer member 40. This effectively prevents the high-temperature medium from transferring to adjacent battery cell assemblies 20 and suppresses heat spread.

[0057] It can be understood that the buffer member 40 also extends along the first direction x, and the exhaust channel 50 corresponding to one battery cell assembly 20 also extends along the first direction x.

[0058] In one embodiment, the projection of the liquid cooling plate 30 and the projection of the explosion-proof valve 212 do not overlap within a projection plane parallel to the surface 2111. This prevents the liquid cooling plate 30 from obstructing the explosion-proof valve 212 and does not occupy the valve opening space and exhaust space of the explosion-proof valve 212, thereby improving exhaust capacity.

[0059] Liquid cooling plates 30 are installed on both sides of the explosion-proof valve 212. In a projection plane parallel to the surface 2111 (i.e., perpendicular to the second direction z), the projection of the liquid cooling plates 30 and the projection of the explosion-proof valve 212 do not overlap. Because the liquid cooling plates 30 and the explosion-proof valve 212 do not overlap in a projection plane parallel to the surface 2111, and the liquid cooling plates 30 extend along the first direction x, the liquid cooling plates 30 on either side of the explosion-proof valve 212 are arranged along the third direction y. Herein, "both sides" of the explosion-proof valve 212 refer to both sides of the explosion-proof valve 212 in the third direction y.

[0060] For each cell assembly 20, two liquid cooling plates 30 and two buffers 40 are positioned between it and the housing wall 121 of the housing 10. The exhaust passage 50 formed by the housing 10, the two buffers 40, the two liquid cooling plates 30, and the cell assembly 20 extends along a first direction. Specifically, the exhaust passage 50 is formed by the housing wall 121 of the housing 10, the facing walls of the two buffers 40, the facing walls of the two liquid cooling plates 30, and the face portions 2111 of each cell 21 in the cell assembly 20.

[0061] When multiple battery cell assemblies 20 are disposed within the battery pack housing 10, the multiple battery cell assemblies 20 are arranged along the third direction y. The figure illustrates an example in which two battery cell assemblies 20 are disposed within the housing 10. In other embodiments, three, four, or six battery cell assemblies 20 may be disposed within the housing 10.

[0062] With the above solution, liquid cooling plates 30 are provided on both sides of the explosion-proof valve 212 of the battery cell assembly 20 of the battery pack, and the liquid cooling plates 30 do not block the explosion-proof valve 212. A buffer member 40 is provided between the liquid cooling plate 30 and the shell wall portion 121 facing the explosion-proof valve 212. In this way, when a battery cell 21 in the battery cell assembly 20 experiences thermal runaway, causing the explosion-proof valve 212 to rupture and eject high-temperature medium, the liquid cooling plate 30 will not occupy the valve opening space of the explosion-proof valve 212 and the exhaust space of the battery pack. The exhaust capacity can be improved. The erupted high-temperature medium can melt through the liquid cooling plate 30 adjacent to the explosion-proof valve 212, so that the cooling medium in the liquid cooling plate 30 is sprayed to the battery cell 21 in thermal runaway and its adjacent battery cells 21 for cooling. At the same time, blocked by the liquid cooling plates 30 and the buffer parts 40 on both sides of the explosion-proof valve 212, most or even all of the high-temperature medium will be transmitted along the exhaust channel 50, which can reduce or even prevent the high-temperature medium from flowing to the adjacent battery cell assembly 20, and can effectively suppress the occurrence of heat spread.

[0063] Figure 4 The black arrows in the figure indicate the flow direction of the high-temperature medium ejected outward from the battery cell 21 in thermal runaway in the exhaust channel 50 .

[0064] When the battery pack is operating normally, the liquid cooling plate 30 can absorb heat by evaporation to cool the battery cells 21. The extension length of the liquid cooling plate 30 in the first direction x should be able to cover all the battery cells 21 of the battery cell assembly 20 to ensure cooling or heat dissipation of each battery cell 21.

[0065] The battery pack can also be provided with two collecting pipes 70 extending along the third direction y, one collecting pipe 70 is connected to one end of each liquid cooling plate 30 in the first direction x, and the other collecting pipe 70 is connected to the other end of each liquid cooling plate 30 in the first direction x. The collecting pipe 70 can be connected to an external heat exchange device to form a circulation loop of the cooling medium, so that the cooling medium can flow between each liquid cooling plate 30 and the external heat exchange device to ensure that the cooling medium in the liquid cooling plate 30 has a relatively low temperature, so as to improve the heat dissipation effect of the battery cell 21.

[0066] Please refer to Figure 5 , Figure 5 The schematic diagram of the structure of the battery pack shell in a specific embodiment is shown, and combined with Figure 1In this embodiment, the battery pack housing 10 includes a box body 11 and an upper cover 12; the box body 11 has a accommodating cavity, which is used to install the battery cell assembly 20 and can also be used to install electrical components related to the battery cell assembly 20. In the illustrated example, the accommodating cavity of the box body 11 is divided into a first chamber 101 and a second chamber 102 by a partition, wherein the first chamber 101 can be used to install the battery cell assembly 20, and the second chamber 102 can be used to install the electrical components; the upper cover 12 is used to block the opening of the box body 11 to close the accommodating cavity, so that the battery cell assembly 20 and the electrical components are in a relatively closed space. The upper cover 12 and the box body 11 can be connected in a detachable manner to facilitate maintenance of the battery cell assembly 20 or the electrical components. The detachable connection method can be a connection method using fasteners such as bolts or screws.

[0067] Combine Figure 2 and Figure 3 In the illustrated example, the upper cover 12 includes the aforementioned shell wall portion 121, and the battery cell 21 of the battery cell assembly 20 is installed in the outer shell 10 with the explosion-proof valve 212 facing the upper cover 12. In this state, the buffer member 40 is located between the upper cover 12 and the liquid cooling plate 30.

[0068] In application, the bottom surface of the battery cell 21 facing away from the explosion-proof valve 212 can be fixed to the bottom wall of the box body 11 by bonding or other methods.

[0069] In application, the bottom wall of the box body 11 can be set as a cold plate structure, and a cooling medium can flow therein to dissipate heat from the bottom of the battery cell 21, thereby improving the charge and discharge performance and cycle life of the battery cell 21.

[0070] In other embodiments, the battery cell 21 can also be installed in the outer shell 10 with the explosion-proof valve 212 facing away from the upper cover 12. In this state, the bottom wall of the box body 11 opposite to the upper cover 12 is the aforementioned shell wall portion, and the buffer member 40 is located between the bottom wall of the box body 11 and the liquid cooling plate 30.

[0071] In one embodiment, the shell wall 121 can be made of steel, aluminum alloy, glass fiber composite material, or carbon fiber composite material. This ensures the structural strength of the shell wall 121. When aluminum alloy or composite material is used to make the shell wall 121, it can also help reduce the weight of the battery pack.

[0072] The thickness of the shell wall portion 121 may be 0.2 mm to 8 mm. The thickness of the shell wall portion 121 may be set according to the material of the shell wall portion 121 to ensure the structural strength and flatness of the shell wall portion 121 .

[0073] The wall surface of the shell wall portion 121 facing the battery cell 21 may also be integrated with a fireproof layer, and the thickness of the fireproof layer may be 0.1 mm to 3 mm. In this way, the safety of the battery pack can be improved.

[0074] Exemplarily, the material of the fireproof layer integrated into the shell wall portion 121 can be a mica board, or a ceramic composite tape, or a fireproof spray coating, etc.

[0075] Please refer to Figures 6 to 9 , Figure 6 This is a partial structural diagram of a cell assembly of a battery pack in one embodiment of the present application. Figure 7 for Figure 6 Schematic diagram of the structure of the battery cell. Figure 8 This is a schematic diagram of the assembly of the liquid cooling plate and the battery cell assembly in a specific embodiment. Figure 9 Schematic diagram of the structure of a battery cell assembly assembled with a liquid cooling plate in a specific embodiment.

[0076] In one embodiment, the two poles 213 of the battery cell 21 and the explosion-proof valve 212 are located on the same side of the battery cell 21. Figure 6 As shown, two poles 213 are respectively provided on both sides of the explosion-proof valve 212 .

[0077] The battery cell 21 includes a top cover 211 and a housing 214. The pole 213 and explosion-proof valve 212 of the battery cell 21 are both located on the top cover 211. The explosion-proof valve 212 is located in a weak area to facilitate opening the explosion-proof valve 212 in the event of a loss of control of the battery cell 21. The pole 213 protrudes from the surface of the top cover 211.

[0078] The surface of the top cover 211 of the battery cell 21 forms the aforementioned face portion 2111 of the battery cell 21 facing the housing wall portion 121 .

[0079] The battery cell assembly 20 includes a plurality of electrical connection pieces 22 , and the electrical connection pieces 22 are used to connect the poles 213 of two adjacent battery cells 21 . Figure 7 In the figure, three battery cells 21 are arranged in series, and the three battery cells 21 are connected in series through multiple electrical connecting pieces 22. In other embodiments, the battery cells 21 of the battery cell assembly 20 can also be connected in parallel through the electrical connecting pieces 22. In the application, the battery cells 21 can be connected in series or in parallel as needed.

[0080] Whether connected in series or in parallel, multiple electrical connection sheets 22 electrically connect the cells 21 of the cell assembly 20 to form an electrical connection sheet row. In a specific implementation, the liquid cooling plate 30 is attached to the electrical connection sheet row, that is, the liquid cooling plate 30 is connected to the electrical connection sheet 22.

[0081] The liquid cooling plate 30 is connected to the electrical connection piece 22 . When the battery pack is operating normally, the liquid cooling plate 30 can also dissipate heat from the electrical connection piece 22 and the pole 213 of the battery cell 21 .

[0082] In this embodiment, the liquid cooling plate 30 is bonded to the electrical connection sheet 22. Figure 6 and Figure 8An adhesive layer 60 is provided between the electrical connection sheet 22 and the liquid cooling plate 30, through which the liquid cooling plate 30 is bonded to the electrical connection sheet 22. The adhesive layer 60 fills the gap between the liquid cooling plate 30 and the electrical connection sheet 22, reducing the chance of the erupted high-temperature medium flowing to adjacent battery cell assemblies 20 and thus helping to suppress heat spread.

[0083] After the above arrangement, the shell wall 121 of the shell 10, the two buffer parts 40, the two liquid cooling plates 30, the poles 213 on both sides of the explosion-proof valve 212, the electrical connecting piece 22 and the wall surface of the battery cell assembly 20 facing the shell wall 121 form an exhaust channel 50.

[0084] Please refer to Figure 10 and Figure 11 , Figure 10 for Figure 6 Schematic diagram of the structure of the CEC connector. Figure 11 for Figure 10 A side view of the electrical connection piece is shown.

[0085] In one embodiment, the electrical connecting piece 22 includes a first connecting piece portion 221, a flexible bending piece portion 222 and a second connecting piece portion 223 connected in sequence. The first connecting piece portion 221 and the second connecting piece portion 223 are respectively used to electrically connect to the poles 213 of two adjacent battery cells 21, and the flexible bending piece portion 222 is bent toward the direction of the face portion 2111.

[0086] In the illustrated example, the flexible bending piece 222 is bent toward the direction where the top cover 211 of the battery cell 21 is located.

[0087] After the above arrangement, when the battery cell 21 expands after multiple cycles of use, the flexible bending piece 222 can absorb the tensile deformation caused by the expansion of the battery cell 21, thereby preventing the pole 213 from being excessively pulled and ensuring the reliability of the electrical connection between two adjacent battery cells 21.

[0088] Since the electrical connection piece 22 is used to connect the poles 213 of two adjacent battery cells 21 , the extension direction of the electrical connection piece 22 , that is, the arrangement direction of the first connection piece portion 221 , the flexible bending piece portion 222 and the second connection piece portion 223 is parallel to the first direction x.

[0089] In a specific implementation, the bending depth of the flexible bending piece 222 toward the face portion 2111 is a, where 0.5 mm ≤ a ≤ 5 mm. The bending depth of the flexible bending piece 222 is related to the amount of tensile deformation it can absorb. In practice, the bending depth of the flexible bending piece 222 can be set based on the deformation caused by the expansion of the battery cell 21, the height of the pole 213 protruding from the top cover 211, and other factors.

[0090] In a specific implementation, the dimension b of the flexible bend portion 222 in the extension direction of the electrical connection piece 22 (i.e., the first direction x) is 3 mm ≤ b ≤ 30 mm. The dimension b of the flexible bend portion 222 is also related to the amount of tensile deformation it can absorb. In practice, the dimension b of the flexible bend portion 222 can be set based on the deformation caused by the expansion of the battery cell 21, the distance between the poles 213 of two adjacent battery cells 21, and other factors.

[0091] Illustratively, the settings of the aforementioned parameters a and / or b of the flexible bending piece 222 can ensure that the pole 213 of the battery cell 21 will not be subjected to a pulling force greater than 1000N.

[0092] Please refer to Figure 12 , Figure 12 A partial cross-sectional view of a battery pack in one embodiment provided in the present application.

[0093] In one embodiment, the dimension of the buffer member 40 in the second direction z is h, which can be understood as the thickness of the buffer member 40 is h, and the distance between the plate surface of the liquid cooling plate 30 facing the shell wall portion 121 and the wall surface of the shell wall portion 121 facing the liquid cooling plate 30 in the second direction z is d, 0.5≤h / d≤20.

[0094] Here, the thickness h of the buffer member 40 refers to the size of the buffer member 40 in a natural state.

[0095] The thickness h of the buffer member 40 can be smaller than the distance d, which facilitates assembly of the battery pack housing 11 and upper cover 12. In this solution, although a gap exists between the buffer member 40 and the housing wall 121, the provision of the buffer member 40 reduces the chance of the erupted high-temperature medium flowing to adjacent battery cell assemblies 20, thereby helping to suppress heat spread.

[0096] The thickness h of the buffer 40 can also be set greater than the distance d. The buffer 40 is elastic. After assembly, the upper cover 12 can compress the buffer 40 so that the buffer 40 is tightly against the liquid cooling plate 30 and the shell wall 121. There is no gap between the buffer 40 and the shell wall 121, which can prevent the high-temperature medium from flowing to the adjacent battery cell assembly 20, and has a better effect of inhibiting heat spread.

[0097] When the thickness h of the buffer 40 is greater than the distance d, the specific value of the thickness h of the buffer 40 is related to the compressibility of the buffer 40, the material of the upper cover 12, etc. The thickness h of the buffer 40 can be based on ensuring the flatness of the upper cover 12 after assembly.

[0098] In one embodiment, the ratio of the thickness h of the buffer member 40 to the distance d may be 0.8-1.5, which can take into account both the effect of suppressing heat spread and the convenience of assembly.

[0099] For example, the buffer member 40 may be made of silicone foam, melamine foam, or polyurethane foam, all of which have good compressibility and fireproofing effects.

[0100] In one embodiment, the dimension of the buffer 40 in the third direction y is w1, and the dimension of the liquid cooling plate 30 in the third direction y is w2, where 0.1 ≤ w1 / w2 ≤ 10. The ratio of the dimension w1 of the buffer 40 to the dimension w2 of the liquid cooling plate 30 affects the width of the exhaust passage 50 (the dimension in the third direction y) and is also related to the ease of assembly of the buffer 40 and the housing 10. The ratio can be adjusted to meet various application requirements.

[0101] In one embodiment, 0.5≤w1 / w2≤1, that is, the size w1 of the buffer 40 is not larger than the size w2 of the liquid cooling plate 30 , so as to save the material cost of the buffer 40 while taking into account the exhaust capacity of the exhaust channel 50 .

[0102] In one embodiment, the distance between the two liquid cooling plates 30 corresponding to a battery cell assembly 20 in the third direction y is w3, and the dimension of the battery cell 21 in the third direction y is w4, where 0.1 ≤ w3 / w4 ≤ 0.8. This allows the exhaust channel 50 to have an appropriate width to facilitate the discharge of high-temperature media in the event of thermal runaway.

[0103] In one embodiment, the distance between the face portion 2111 of the battery cell 21 and the shell wall portion 121 in the second direction z is h1, 6mm≤h1≤20mm. This ensures the height of the exhaust channel 50, which helps improve the exhaust capacity of the battery pack after the battery cell 21 experiences thermal runaway.

[0104] In one embodiment, if Figure 4 As shown, the distance D between the liquid cooling plate 30 and the explosion-proof valve 212 in the third direction y is 0 mm ≤ D ≤ 30 mm. This prevents the liquid cooling plate 30 from blocking the explosion-proof valve 212 while also ensuring the width of the exhaust passage 50, ensuring the battery pack's exhaust capacity and allowing the erupted high-temperature medium to quickly melt through the liquid cooling plate 30.

[0105] In one embodiment, Figure 3 As shown, the distance between the surface 2111 of the liquid cooling plate 30 facing the battery cell 21 and the explosion-proof valve 212 in the second direction z is H, where 0 mm ≤ H ≤ 20 mm. This allows the high-temperature medium ejected after the explosion-proof valve 212 ruptures to be transferred to the liquid cooling plate 30 as quickly as possible, allowing the liquid cooling plate 30 to melt through and cool the battery cell 21 experiencing thermal runaway and its adjacent cells 21.

[0106] In one embodiment, the wall thickness of the liquid cooling plate 30 can be 0.1 mm to 2 mm, and / or the liquid cooling plate 30 can be a tube made of aluminum alloy or thermoplastic, and / or the melting point of the liquid cooling plate 30 is not higher than 500°C. In this way, when a battery cell 21 experiences thermal runaway, the erupting high-temperature medium can quickly melt through the liquid cooling plate 30, thereby promptly cooling the thermally runaway battery cell 21 and adjacent battery cells 21. This also prevents the liquid cooling plate 30 from melting through during normal operation of the battery pack.

[0107] For example, the liquid cooling plate 30 may be made of a material with a melting point of 220° C. to 300° C.

[0108] In a specific implementation, the liquid cooling plate 30 can be in the form of a harmonica tube, with multiple parallel cooling channels. The cooling channels of the liquid cooling plate 30 contain a cooling medium, which can be water, 50% ethylene glycol coolant, or fluorinated liquid. This ensures cooling efficiency while reducing costs.

[0109] An embodiment of the present application also provides a vehicle, which includes the battery pack introduced in the above embodiment and has technical effects corresponding to the above battery pack, which will not be repeated.

[0110] This document uses specific examples to illustrate the principles and implementation methods of this application. The description of the above examples is only intended to help understand the method and core ideas of this application. It should be noted that for those skilled in the art, without departing from the principles of this application, various improvements and modifications can be made to this application, and such improvements and modifications also fall within the scope of protection of the claims of this application.

Claims

1. A battery pack, characterized in that: It includes a housing (10), a battery cell (21) and a liquid cooling plate (30); The battery core (21) is located in the housing (10), and the explosion-proof valve (212) of the battery core (21) faces the housing wall (121) of the housing (10); The liquid cooling plate (30) is connected to the surface (2111) of the battery core (21) facing the shell wall (121), and the liquid cooling plate (30) is provided on both sides of the explosion-proof valve (212); The housing (10), the two liquid cooling plates (30) and the battery core (21) form an exhaust channel (50).

2. The battery pack according to claim 1, wherein: The battery pack further includes a buffer member (40), the buffer member (40) being arranged between the liquid cooling plate (30) and the shell wall portion (121), and the shell (10), the two buffer members (40), the two liquid cooling plates (30) and the battery cell (21) forming the exhaust channel (50).

3. The battery pack according to claim 2, wherein: The dimension of the buffer member (40) in the second direction is h, the distance between the plate surface of the liquid cooling plate (30) facing the shell wall portion (121) and the wall surface of the shell wall portion (121) facing the liquid cooling plate (30) in the second direction is d, 0.5≤h / d≤20; the second direction is the normal direction of the face portion (2111); And / or, the dimension of the buffer member (40) in the third direction is w1, the dimension of the liquid cooling plate (30) in the third direction is w2, 0.1≤w1 / w2≤10; and the third direction is the arrangement direction of the two liquid cooling plates (30).

4. The battery pack according to claim 1, wherein: In a projection plane parallel to the face portion (2111), the projection of the liquid cooling plate (30) and the projection of the explosion-proof valve (212) do not overlap.

5. The battery pack according to any one of claims 1 to 4, characterized in that: A plurality of battery cells (21) are arranged in the housing (10), the plurality of battery cells (21) are arranged along a first direction, the liquid cooling plate (30) extends along the first direction, and the exhaust passage (50) extends along the first direction; the battery pack includes a plurality of electrical connection pieces (22), the battery cells (21) are provided with poles (213) on both sides of the explosion-proof valve (212), and the electrical connection pieces (22) connect the poles (213) of two adjacent battery cells (21); and the liquid cooling plate (30) is bonded to the electrical connection pieces (22).

6. The battery pack according to claim 5, characterized in that: The electrical connecting piece (22) comprises a first connecting piece portion (221), a flexible bending piece portion (222), and a second connecting piece portion (223) connected in sequence, the first connecting piece portion (221) and the second connecting piece portion (223) being respectively used for electrically connecting to the poles (213) of two adjacent battery cells (21), and the flexible bending piece portion (222) being bent in the direction of the face portion (2111); The bending depth of the flexible bending piece (222) is a, 0.5 mm ≤ a ≤ 5 mm; and / or the dimension of the flexible bending piece (222) in the extension direction of the electrical connection piece (22) is b, 3 mm ≤ b ≤ 30 mm.

7. The battery pack according to any one of claims 1 to 4, characterized in that: The distance between the two liquid cooling plates (30) in the third direction is w3, the size of the battery cell (21) in the third direction is w4, and 0.1≤w3 / w4≤0.8; and / or, the distance between the face portion (2111) of the battery cell (21) and the shell wall portion (121) in the second direction is h1,6mm≤h1≤20mm; And / or, the distance between the liquid cooling plate (30) and the explosion-proof valve (212) in the third direction is D, 0mm≤D≤30mm; And / or, the distance between the plate surface of the liquid cooling plate (30) facing the face portion (2111) and the explosion-proof valve (212) in the second direction is H, 0mm≤H≤20mm; The second direction is the normal direction of the face (2111), and the third direction is the arrangement direction of the two liquid cooling plates (30).

8. The battery pack according to any one of claims 1 to 4, characterized in that: The wall thickness of the liquid cooling plate (30) is 0.1 mm to 2 mm; And / or, the liquid cooling plate (30) is a pipe made of aluminum alloy or thermoplastic plastic; and / or, the melting point of the liquid cooling plate (30) is not higher than 500°C; And / or, the liquid cooling plate (30) has a cooling channel, the cooling channel has a cooling medium, and the cooling medium is water, or 50% ethylene glycol cooling liquid, or fluorinated liquid.

9. The battery pack according to any one of claims 1 to 4, characterized in that: The shell wall portion (121) is made of steel, or aluminum alloy, or glass fiber composite material, or carbon fiber composite material; And / or, the thickness of the shell wall portion (121) is 0.2 mm to 8 mm; And / or, a fireproof layer is integrated on the wall surface of the shell wall portion (121) facing the battery core (21), and the thickness of the fireproof layer is 0.1 mm to 3 mm.

10. A vehicle, characterized in that: The vehicle includes the battery pack according to any one of claims 1 to 9.

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