Battery module, battery pack and vehicle

Abstract

The present invention relates to the field of vehicle technology, and in particular to a battery module, a battery pack and a vehicle. The battery module includes a spray device and a battery cell, the battery cell having a first end face and a second end face, the pole of the battery cell is located at the first end face, the explosion-proof valve of the battery cell is located at the second end face, and the explosion-proof valve and the pole are respectively arranged on the first end face and the second end face of the battery cell, so that when the explosion-proof valve is opened by a high-temperature substance, the high-temperature substance escaping from the explosion-proof valve will not affect the pole, thereby avoiding a short circuit of the battery module, and other batteries of the battery module that are not in thermal runaway can still work normally. The spray device is located on one side of the second end face, and the projections of the spray device and the explosion-proof valve do not overlap in a direction perpendicular to the second end face, and at least part of the spray device is located within the spray range of the explosion-proof valve, so that the spray device will not hinder the opening of the explosion-proof valve, so that the high-temperature substance can be smoothly sprayed out from the explosion-proof valve, so as to prevent the internal pressure of the thermal runaway battery cell from continuing to rise and avoid failure of the battery cell structure.

Description

Technical Field

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

[0002] Lithium-ion power batteries have become the mainstream of automotive power batteries in the current new energy industry. They have the advantages of high energy density and long cycle life. However, when power batteries are over-discharged, over-charged, over-heated or have other internal quality problems, there is a risk of thermal runaway.

[0003] In the related art, a spray device is generally arranged directly above the battery cell explosion-proof valve. When thermal runaway occurs in the battery cell, the battery cell explosion-proof valve is opened, and high-temperature material is sprayed out from the battery cell explosion-proof valve. The high-temperature material can cause the spray device to melt through and release cooling medium into the battery cell explosion-proof valve to cool the battery cell, thereby suppressing the spread of heat from the runaway battery cell to the adjacent battery cells.

[0004] However, installing a spray device directly above the battery cell explosion-proof valve will hinder the opening and exhaust of the battery cell explosion-proof valve, resulting in the accumulation of eruptive materials and increased pressure in the package, posing a risk of structural failure.

[0005] Therefore, a battery module is urgently needed to solve the above technical problems. Summary of the invention

[0006] The object of the present invention is to provide a battery module, a battery pack and a vehicle to ensure that the spray device does not hinder the opening and exhaust of the explosion-proof valve and can cool the explosion-proof valve.

[0007] To achieve this object, the present invention adopts the following technical solutions:

[0008] Battery module, including:

[0009] A battery cell, wherein the battery cell has a first end surface and a second end surface, a pole of the battery cell is located on the first end surface, and an explosion-proof valve of the battery cell is located on the second end surface;

[0010] a spray device, disposed relative to the second end surface;

[0011] The projection of the spray device on the second end surface does not overlap with the explosion-proof valve, and at least a portion of the spray device is located within the spray range of the explosion-proof valve.

[0012] As a preferred technical solution of the above-mentioned battery module, a portion of the spray device located within the spraying range is provided with a weak area.

[0013] And / or, the spray device is a liquid cooling component made of composite material.

[0014] As a preferred technical solution of the above-mentioned battery module, the liquid cooling component is connected to a liquid cooling circuit, and at least a portion of the outer wall of the liquid cooling component is in contact with the second end surface.

[0015] As a preferred technical solution of the above battery module, the melting point of the meltable part of the spray device is ≤400°C;

[0016] And / or, the wall thickness of the meltable portion is 0.1 mm to 2 mm.

[0017] As a preferred technical solution of the above battery module, along the direction perpendicular to the second end face, the distance between the spray device and the second end face is 0 to 20 mm; and / or,

[0018] The projection of the spray device on the second end surface and the offset of the explosion-proof valve are 0 to 30 mm.

[0019] As a preferred technical solution of the above battery module, the ratio of the cross-sectional area of ​​the spray device to the capacity of the battery cell is greater than 0.4mm 2 / Ah.

[0020] As a preferred technical solution for the above-mentioned battery module, there are multiple battery cells, and the multiple battery cells are arranged in an array and form at least one battery cell group arranged along a first direction. The spray device extends along the arrangement direction of the battery cell group, and the length of the spray device is greater than or equal to the total length of the multiple battery cells arranged in the first direction.

[0021] As a preferred technical solution of the above battery module, the first direction is the width direction of the battery cell, the two spray devices are arranged at intervals along the width direction of the battery cell, and the explosion-proof valve is located between the two spray devices;

[0022] Alternatively, the first direction is the length direction of the battery core, the two spray devices are arranged at intervals along the length direction of the battery core, and the explosion-proof valve is located between the two spray devices.

[0023] The present invention also provides a battery pack, including a battery box, in which a plurality of battery modules described in any of the above schemes are arranged.

[0024] The present invention also provides a vehicle, comprising a vehicle body and the above-mentioned battery pack, wherein the battery pack is arranged on the vehicle body.

[0025] The present invention has at least the following beneficial effects:

[0026] The battery module, battery pack and vehicle provided by the present invention all include a spray device and a battery cell. The battery cell has a first end face and a second end face. The pole of the battery cell is located at the first end face, and the explosion-proof valve of the battery cell is located at the second end face. The explosion-proof valve and the pole are respectively arranged on the first end face and the second end face of the battery cell, so that when the explosion-proof valve is opened by a high-temperature substance, the high-temperature substance escaping from the explosion-proof valve will not affect the pole, thereby avoiding a short circuit of the battery module, and other battery cells of the battery module that are not in thermal runaway can still work normally. The spray device is arranged relative to the second end face, and the projection of the spray device on the second end face does not overlap with the explosion-proof valve. At least part of the spray device is located within the spray range of the explosion-proof valve, so that the spray device will not hinder the opening of the explosion-proof valve, so that the high-temperature substance can be smoothly sprayed out from the explosion-proof valve, so as to prevent the internal pressure of the thermal runaway battery cell from continuing to rise and avoid failure of the battery cell structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments of the present invention. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the contents of the embodiments of the present invention and these drawings without paying any creative work.

[0028] Figure 1 A schematic diagram of the bonding state between the spray device and the battery cell provided in an embodiment of the present invention;

[0029] Figure 2 A schematic diagram of a spray device and a battery cell in a non-attached state provided by an embodiment of the present invention;

[0030] Figure 3 A schematic diagram of the structure of a battery module provided in an embodiment of the present invention Figure 1 ;

[0031] Figure 4 A schematic diagram of the structure of a battery module provided in an embodiment of the present invention Figure 2 ;

[0032] Figure 5 An exploded schematic diagram of a battery pack provided in an embodiment of the present invention;

[0033] Figure 6 A cross-sectional view of a battery pack provided by an embodiment of the present invention Figure 1 ;

[0034] Figure 7 A cross-sectional view of a battery pack provided by an embodiment of the present invention Figure 2 .

[0035] In the figure:

[0036] 1. Spray device; 2. Battery cell; 3. Bar; 4. Explosion-proof valve; 5. Buffer layer; 6. Shell; 7. Exhaust channel; 8. Current collector. DETAILED DESCRIPTION

[0037] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only parts related to the present invention, rather than all structures, are shown in the accompanying drawings.

[0038] In the description of the present invention, unless otherwise clearly specified and limited, the terms "connected", "connected", and "fixed" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0039] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0040] In the description of this embodiment, the terms "upper", "lower", "right", etc., directions or positional relationships are based on the directions or positional relationships shown in the drawings, and are only for the convenience of description and simplification of operation, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are only used to distinguish in the description and have no special meaning.

[0041] The present invention is based on the inventor's discovery and understanding of the following facts and problems:

[0042] In the related art, a spray device is generally arranged directly or partially directly opposite to the explosion-proof valve of the battery cell. When thermal runaway occurs in the battery cell, the spray device is opened by active opening or passive melting to release the cooling medium in the spray device to the explosion-proof valve of the runaway battery cell, thereby cooling the runaway battery cell and adjacent battery cells, thereby suppressing the spread of heat from the runaway battery cell to the adjacent battery cells.

[0043] However, the related technology has the following defects: when the distance between the spray device and the explosion-proof valve is less than or equal to 5mm, the spray device will hinder the opening of the battery cell explosion-proof valve; for this reason, the distance between the spray device and the battery cell explosion-proof valve is increased in the related technology, but when the distance between the spray device and the battery cell explosion-proof valve is less than or equal to 8mm, the spray device hinders the exhaust space after the battery cell erupts, thereby causing the accumulation of erupted high-temperature materials, increasing the pressure in the battery pack and creating the risk of structural failure; if the distance between the spray device and the explosion-proof valve continues to increase until the distance between the spray device and the explosion-proof valve is greater than 8mm, the space integration efficiency of the battery pack will be reduced.

[0044] In theory, the explosion-proof valve sprays high-temperature substances out of the battery cell in a direction perpendicular to the battery cell. Those skilled in the art are accustomed to setting the spray device and the explosion-proof valve at least partially opposite each other, and subjectively believe that the spray device cannot be effectively melted through when the projection of the spray device on the end face where the explosion-proof valve is located does not overlap with the explosion-proof valve. For this reason, the relevant technology adopts the method of at least partially facing the spray device and the explosion-proof valve to ensure that the spray device can be melted through, thereby ignoring the solution of staggering the spray device and the explosion-proof valve, and no further research has been conducted on the staggered arrangement.

[0045] The present invention can avoid the defects and problems in the related art by staggering the arrangement of the spray device and the explosion-proof valve, that is, the projection of the spray device on the end face where the explosion-proof valve is located does not overlap with the explosion-proof valve. In addition, considering that the spray device cannot be melted through by the high-temperature material sprayed from the thermally runaway battery cell at all positions, the present invention conducts multiple tests and studies on the positional relationship between the spray device and the explosion-proof valve, and confirms the spray range in which the explosion-proof valve can melt through the spray device when the battery cell is thermally runaway, wherein the spray range is specifically the area range where the high-temperature material actually passes and the area range where the high-temperature material can effectively melt through at least part of the spray device by heat transfer. The spray device is at least partially arranged within the spray range of the explosion-proof valve, so that the runaway high-temperature material can melt through the spray device by direct contact or heat transfer (such as heat radiation, heat conduction, heat convection).

[0046] The inventors have obtained the battery module provided by the present invention through continuous efforts. When one of the battery cells has thermal runaway, the spray device can be melted through by the high-temperature material sprayed from the explosion-proof valve, so that the cooling medium in the spray device flows out from the melted position to the out-of-control battery cell, and part of the cooling medium enters the battery cell, realizing the internal and external cooling of the out-of-control battery cell and the surface cooling of the adjacent battery cell, thereby inhibiting the heat spread from the out-of-control battery cell to the adjacent battery cell. This effectively overcomes the technical prejudice mentioned above by those skilled in the art that the spray device cannot be effectively melted through when the projection of the spray device on the end face where the explosion-proof valve is located does not overlap with the explosion-proof valve.

[0047] In an embodiment of the present invention, a battery module is provided, the battery module includes a spray device and a battery cell, the battery cell has a first end face and a second end face, the pole is located at the first end face of the battery cell, the explosion-proof valve is located at the second end face of the battery cell, and the spray device is arranged opposite to the second end face, wherein the projection of the spray device on the second end face does not overlap with the explosion-proof valve, and at least part of the spray device is located within the spray range of the explosion-proof valve, so that it can be ensured that the spray device can be at least partially melted through to spray out the cooling medium when the explosion-proof valve sprays high-temperature substances outward. The projection of the spray device on the second end face does not overlap with the explosion-proof valve. It can be understood that the spray device is completely arranged to avoid the explosion-proof valve, that is, the spray device is completely deviated from the explosion-proof valve, and the spray device can be melted through and spray the cooling medium to the explosion-proof valve when the explosion-proof valve is opened.

[0048] Among them, the spray device is at least partially located within the spray range of the explosion-proof valve, which means that part of the spray device is located within the spray range of the explosion-proof valve, that is, part of the spray device can be melted through and the cooling medium can be sprayed to the explosion-proof valve, or the spray device is completely located within the spray range of the explosion-proof valve and is completely melted through to release the cooling medium and spray it to the explosion-proof valve.

[0049] In addition, it should be noted that the projection of the spray device on the second end surface is an orthographic projection along a direction perpendicular to the second end surface.

[0050] When a battery cell experiences thermal runaway, the explosion-proof valve of the battery cell is opened and sprays out high-temperature material with a temperature ≥500°C. The sprayed high-temperature material can melt through the spray device close to the explosion-proof valve in a very short time, and the cooling medium flows out from the melted position, thereby cooling the battery cell in thermal runaway. The cooling medium is sprayed directly onto the surface of the battery cell and the inside of the battery cell for direct cooling, and the battery cell and ambient temperature are indirectly cooled by absorbing heat through evaporation.

[0051] Since the explosion-proof valve and the pole are located on the second end face and the first end face of the battery cell respectively, when the explosion-proof valve is opened by high-temperature substances, the high-temperature substances released from the explosion-proof valve will not affect the pole, thus preventing the battery module from short-circuiting, and other batteries in the battery module that are not in thermal runaway can still work normally. Since the projections of the spray device and the explosion-proof valve in the direction perpendicular to the second end face do not overlap, the spray device will not hinder the opening of the explosion-proof valve, and the high-temperature substances can be smoothly sprayed out from the explosion-proof valve, thereby preventing the internal pressure of the thermal runaway battery cell from continuing to rise and avoiding failure of the battery cell structure.

[0052] In some embodiments, Figure 1-2 As shown, the first end face and the second end face are arranged opposite to each other along the height direction of the battery cell 2, wherein the pole is located at the first end face of the battery cell 2, the explosion-proof valve 4 is located at the second end face of the battery cell 2, the spray device 1 is arranged opposite to the second end face, and the projection of the spray device 1 on the second end face does not overlap with the explosion-proof valve 4, and at least a part of the spray device 1 is located within the spray range of the explosion-proof valve 4.

[0053] Of course, in some other embodiments, the first end face and the second end face may also be arranged vertically adjacent to each other, as long as it can be ensured that the pole and the explosion-proof valve 4 are not on the same end face.

[0054] In some embodiments, a weak area is provided in the spraying range of the spray device 1, wherein the wall thickness of the weak area is thinner than that of other positions of the spray device 1, so that it can be easily melted through. Such a setting can avoid heat spread caused by the spray device 1 not spraying in time.

[0055] In some embodiments, the spray device 1 is a metal material, for example, the spray device 1 is an aluminum alloy structural tube. The aluminum alloy structural tube has a certain strength and can play a certain supporting role for the battery cell. The spray device 1 made of metal material is provided with a weak area in the spray range of the explosion-proof valve 4, so that it is easy to be melted through.

[0056] The number of weak areas can be one or more, and the number of weak areas can be determined according to the actual spraying range. The shape of the weak areas can be circular, rectangular or other irregular shapes, as long as the cooling medium can be sprayed out. Some of the weak areas are arranged toward the explosion-proof valve 4, so that the high-temperature material can be sprayed to the weak areas to melt through the weak areas. Of course, all the weak areas can also be arranged toward the explosion-proof valve 4 to improve the melting rate of the spray device 1.

[0057] In some embodiments, the spray device 1 may also be a liquid cooling member made of a composite material, which can cool the battery cell 2 when the battery cell 2 is in normal working condition, and when the battery cell 2 is in thermal runaway, the liquid cooling member is melted and then sprays out a cooling medium to achieve the purpose of cooling. In some embodiments, the spray device 1 may be a thermoplastic plastic structural tube. The thermoplastic plastic structural tube can be melted at a certain temperature to ensure that the cooling medium is sprayed out from the spray device 1. In some examples, the composite material may be nylon, polyphenylene ether, polypropylene or polycarbonate.

[0058] Since the spray device 1 is made of a composite material, the overall performance tends to be consistent. In some embodiments, the spray device 1 is a liquid-cooled component with the same wall thickness throughout, that is, the spray device 1 does not have a weak area, and the high-temperature material sprayed by the explosion-proof valve 4 can more accurately and timely melt through the part of the spray device 1 within the spraying range.

[0059] In other embodiments, the liquid cooling component made of composite materials may also be provided with a weak area, where the wall thickness of the weak area is thinner than that of other positions of the liquid cooling component, so that it can be easily melted by the high-temperature material sprayed by the explosion-proof valve 4, thereby improving the response capability of the liquid cooling component to the thermal runaway battery cell 2.

[0060] When the battery cell 2 is working normally, the high temperature of the battery cell 2 will cause the chemical reaction rate inside the battery cell 2 to accelerate, and the evaporation of the electrolyte will increase, thereby reducing the capacity of the battery cell 2. In addition, high temperature will also cause the expansion of the internal materials of the battery cell 2, causing damage to the structure of the battery cell 2, further affecting the capacity and performance of the battery cell 2, so it is necessary to cool down the battery cell that is working normally. When the spray device in the related art adopts a composite material, the thermal conductivity of the composite material is low (usually less than or equal to 0.4W / m·K), resulting in the cooling effect of the liquid cooling part made of the composite material on the battery cell 2 being poorer than the cooling effect of the liquid cooling part made of metal material on the battery cell 2. Therefore, in some embodiments, the thermal conductivity of the composite material is ≥0.5W / m·K, specifically, it can be 0.5W / m·K, 0.7W / m·K / , 1.1W / m·K / or higher thermal conductivity. In some examples, the thermal conductivity is 0.5W / m·K. When the thermal conductivity is 0.5W / m·K, it can ensure that the temperature of the cooling medium in the liquid cooling component is kept at a low temperature, and then after the cooling medium is sprayed out, the temperature of the thermal runaway battery cell 2 can be quickly reduced, thereby improving the cooling effect. For example, the composite material is nylon. In some examples, the thermal conductivity is 0.7W / m·K. When the thermal conductivity is 0.7W / m·K, it can ensure the cooling effect of the liquid cooling component on the battery cell 2 as a whole, avoiding the high temperature generated by the operation of the battery cell 2. In some examples, the thermal conductivity is 1.1W / m·K. When the thermal conductivity is 1.1W / m·K, it can ensure the cooling effect of the liquid cooling component on the battery cell 2 as a whole, avoiding the high temperature generated by the operation of the battery cell 2. For example, the composite material can be polyphenylene ether. In some other embodiments, the composite material may be PPA (polyphthalamide) with a thermal conductivity of 0.75 W / m·K, or the composite material may be PPO (polystyrene) with a thermal conductivity of 1 W / m·K.

[0061] Since the temperature of the high-temperature material sprayed from the explosion-proof valve 4 is greater than 500°C, when the melting point of the fusible part of the spray device 1 is higher than 500°C, it cannot be melted by the high-temperature material. To this end, in some embodiments, the melting point of the fusible part of the spray device 1 is less than or equal to 400°C, and the fusible part is a position where the high-temperature material can be melted after being sprayed onto the spray device 1. For example, the fusible part can be a weak area of ​​a metal material part, or a side wall of a liquid cooling part made of a composite material located within the spraying range, or a weak area set for a liquid cooling part made of a composite material. Defining the melting point of the fusible part can ensure that the spray device 1 can melt quickly in a high-temperature environment to ensure that the cooling medium is sprayed from the spray device 1. When the melting point of the fusible part is less than or equal to 400°C, since the melting point of the fusible part is much lower than the temperature of the high-temperature material, the fusible part can be melted after the high-temperature material is sprayed on the fusible part, and the melting response speed is fast, which prevents the high-temperature material from accumulating around the explosion-proof valve 4 and causing the external temperature of the battery cell 2 to rise rapidly. In some examples, the melting point of the fusible portion is 300°C. When the melting point of the fusible portion is 300°C, the spray device 1 can be melted through quickly, so that the cooling medium is sprayed out to achieve the purpose of rapid cooling. For example, the composite material can be polyphenylene ether. In some examples, the melting point of the fusible portion is 400°C. When the melting point of the fusible portion is 400°C, it can avoid the increase in ambient temperature caused by thermal runaway of other battery cells 2. The fusible portion located at the battery cell 2 that has not experienced thermal runaway melts through and sprays the corresponding battery cell 2 to cool it down. This can prevent the cooling medium from being dispersed and unable to concentrate on spraying and cooling the battery cell 2 that has experienced thermal runaway, further preventing heat spread. For example, the composite material can be nylon.

[0062] Optionally, the wall thickness of the fusible portion is 0.1 mm to 2 mm. In some embodiments, the wall thickness of the fusible portion is 0.1 mm, 0.8 mm, 1.4 mm or 2.0 mm, which is not specifically limited here. When the wall thickness of the fusible portion is 0.1 mm, it can be melted through in a relatively short time after the battery cell 2 has a thermal runaway, and then the battery cell 2 can be sprayed at the first time. When the wall thickness of the fusible portion is 0.8 mm, it can avoid the problem of erroneous melting caused by the high temperature of the battery cell 2 without thermal runaway. This can avoid the spraying device from being used again when the battery cell 2 actually has a thermal runaway, and improve the accuracy of cooling to prevent heat spread. When the wall thickness of the fusible portion is 1.4 mm, it can avoid the fusible portion being damaged due to a large impact caused by the thin fusible portion, thereby protecting the overall structure of the sprayable device 1. When the wall thickness of the meltable part is 2 mm, the wall thickness of other parts of the spray device 1 is thicker, which can improve the overall strength of the spray device 1, prevent the spray device 1 from being damaged after being impacted, and ensure that the spray device 1 is melted. The above-mentioned wall thickness limitation can prevent the spray device 1 from taking a long time to melt in the spraying range, and the melted gap becomes smaller and the cooling medium cannot be sprayed in time.

[0063] In some examples, such as Figure 1 As shown, along the direction perpendicular to the second end surface, the distance between the spray device 1 and the second end surface is 0-20 mm, that is, the spray device 1 and the second end surface can be arranged in a close contact or a non-close contact manner.

[0064] When the spray device 1 and the second end face are fitted together, that is, the distance between the spray device 1 and the second end face is 0, this setting enables the spray device 1 to provide cooling medium for the battery cell 2 after thermal runaway, and to provide surface cooling for the battery cell 2 operating normally, and the cooling effect is obvious.

[0065] In some embodiments, the liquid cooling member is connected to the liquid cooling circuit, and at least part of the outer wall of the liquid cooling member is in contact with the second end face. If at least part of the outer wall of the liquid cooling member is in contact with the second end face, it means that part of the outer wall of the liquid cooling member facing the second end face is in contact with the second end face, or all the side walls of the liquid cooling member facing the second end face are in contact with the second end face. The contact of the liquid cooling member with the second end face can cool down the second end face. Since the liquid cooling circuit is connected to the spray device 1, the liquid cooling circuit can provide the spray device 1 with a circulating cooling medium, thereby ensuring that the cooling medium entering the spray device 1 is in a low temperature state. The circulating cooling medium can ensure that the temperature of the cooling medium is continuously maintained at a relatively low temperature to cool down the battery cell 2, thereby ensuring that the battery cell 2 has a good working environment. In addition, it can ensure that the temperature of the cooling medium is maintained at a relatively low temperature when spraying the battery cell 2 in thermal runaway, thereby improving the cooling effect on the battery cell 2 in thermal runaway. The specific structure of the liquid cooling circuit is prior art and will not be described in detail here.

[0066] In some examples, the liquid cooling element may be a harmonica tube, which is at least arranged on one side of the explosion-proof valve 4 and is in contact with the second end face. When the battery cell 2 fails due to thermal failure, high-temperature substances are ejected from the explosion-proof valve 4. Since the liquid cooling element is arranged close to the explosion-proof valve 4, the high-temperature substances can melt through the liquid cooling element, so that the cooling medium in the harmonica tube is sprayed onto the battery cell 2 with thermal runaway and the surface of the surrounding battery cells 2. After the cooling medium flows out from the melted-through part, part of it will enter the inside of the thermal runaway battery cell 2, thereby achieving the purpose of cooling the inside of the battery cell 2, and part of the cooling medium is sprayed on the surface of the battery cell 2, thereby achieving the purpose of cooling the outside of the battery cell 2. In addition, the harmonica tube can also cool the outer surface of other battery cells that have not experienced thermal runaway, thereby achieving the purpose of cooling from different positions of the battery cell 2.

[0067] Since the liquid cooling element is specifically a harmonica tube, the area of ​​the liquid cooling element for cooling the battery cell 2 can be increased, so that the liquid cooling element can dissipate heat for the battery cell 2 when the battery cell 2 works normally. The specific structure of the harmonica tube is prior art and will not be described in detail. In some other embodiments, the liquid cooling element can also be specifically a liquid cooling plate.

[0068] In addition, when the spray device 1 is arranged in close contact with the second end surface, and the spray device 1 and the explosion-proof valve 4 are arranged away from each other, this saves a certain amount of space compared to the arrangement of the spray device 1 and the explosion-proof valve 4 facing each other, making the battery module more compact as a whole.

[0069] like Figure 2 As shown, the spray device 1 and the second end face can also be non-fitted, and the two spray devices 1 are respectively arranged on both sides of the explosion-proof valve 4, the first end face has a pole, and the second end face has an explosion-proof valve 4. In some embodiments, the distance between the spray device 1 and the second end face is 1mm, 9mm or 20mm, which is not specifically limited here. When the distance between the spray device 1 and the second end face is 1mm, since the distance between the spray device 1 and the battery cell 2 is small, the heat dissipated by the battery cell 2 can be absorbed by the spray device 1, which has a good heat dissipation effect. In addition, the spray range of the spray device 1 will also increase accordingly, thereby improving the cooling effect. When the distance between the spray device 1 and the second end face is 9mm, it can also absorb part of the heat dissipated by the battery cell 2. Since the distance between the spray device 1 and the second end face increases, this can further increase the probability of melting the high-temperature material sprayed by the explosion-proof valve, thereby improving the response speed of the spray device 1. When the distance between the spray device and the second end face is 20 mm, it can ensure that the high-temperature material sprayed by the explosion-proof valve is sprayed on the surface of the spray device 1 in time, thereby improving the response speed to the cooling of the thermal runaway battery cell 2. Through the above structural design, since the distance between the spray device 1 and the second end face is small, the spray device 1 is more easily melted by the high-temperature material sprayed by the explosion-proof valve 4, thereby further ensuring the battery module's better response capability to thermal runaway.

[0070] In some embodiments, a heat-conducting layer is provided between the spray device 1 and the second end face, and the provision of the heat-conducting layer can facilitate the conduction of heat from the battery cell 2, and the spray device 1 is provided in a bonded manner with the heat-conducting layer. In some examples, the heat-conducting layer may be a heat-conducting silicone layer or a heat-conducting silicone grease layer. In some examples, the thickness of the heat-conducting layer is 0.5 to 1.5 mm, and specifically, the thickness of the heat-conducting layer is 0.5 mm, 1 mm or 1.5 mm. When the thickness of the heat-conducting layer is 0.5 mm, the heat of the battery cell can be quickly transferred to the spray device 1, and when the thickness of the heat-conducting layer is 1 mm, the spray device 1 and the battery cell 2 can have a good heat-conducting effect, and the spray device 1 can be prevented from overheating and affecting the subsequent cooling of the out-of-control battery cell 2. When the thickness of the heat-conducting layer is 1.5 mm, it can achieve a heat-conducting effect while enabling the spray device to maintain a certain temperature to meet the cooling requirements of the thermal runaway battery cell.

[0071] In some embodiments, Figure 2As shown, along the direction perpendicular to the second end face, the offset between the projection of the spray device 1 on the second end face and the explosion-proof valve 4 is 0 to 30 mm. Optionally, the offset between the projection of the spray device 1 on the second end face and the explosion-proof valve 4 is 0 mm, 1 mm, 10 mm or 30 mm, which is not specifically limited here. The offset between the projection of the spray device 1 on the second end face and the explosion-proof valve 4 is 0 mm. Since the temperature around the explosion-proof valve 4 tends to decrease from near to far, the spray device 1 is arranged close to the explosion-proof valve 4, which can ensure that the position of the spray device 1 close to the explosion-proof valve 4 is melted through as soon as possible, so that the cooling medium is sprayed out to improve the spray device 1's ability to respond to thermal runaway cells. The offset between the projection of the spray device 1 on the second end face and the explosion-proof valve 4 is 1 mm, which can ensure that the spray device 1 does not contact the explosion-proof valve 4, avoiding being melted through by the explosion-proof valve 4 at high temperature without spraying. When the offset between the projection of the spray device 1 on the second end face and the explosion-proof valve 4 is 10mm, it is possible to avoid the temperature of the explosion-proof valve 4 being higher than the temperature of other positions of the battery cell 2. The higher heat is transferred to the spray device 1 through heat transfer, causing the spray device 1 to be melted through by mistake. At the same time, it can also ensure that the spray device 1 and the explosion-proof valve 4 are within the optimal spray range of each other. When the offset between the projection of the spray device 1 on the second end face and the explosion-proof valve 4 is 30mm, it is possible to ensure that the spray range of the spray device 1 is larger, and that the high-temperature area can be sprayed more to cool down. Through the above-mentioned structural design, due to the small offset between the projection of the spray device 1 and the explosion-proof valve 4, the spray device 1 is more easily melted by the high-temperature material sprayed by the explosion-proof valve 4, thereby further ensuring the battery module's better ability to cope with thermal runaway.

[0072] From the comparison table of the effects of the spray device made of an aluminum alloy liquid cooling device and a composite material, it can be seen that: when the spray device 1 and the explosion-proof valve 4 are offset (when the projection of the spray device 1 on the second end surface and the offset of the explosion-proof valve 4 are greater than 0), the difference in the cooling effect is small, and both can meet the demand of suppressing the spread of thermal runaway of the battery cell 2.

[0073] Comparison table of the effects of aluminum alloy liquid cooling device and spray device made of composite materials

[0074]

[0075] From the comparison table of the effects of the aluminum alloy liquid cooling device and the spray device made of composite materials, it can be seen that when the spray device made of composite materials is used, when the projection offset between the explosion-proof valve 4 and the spray device 1 is 1mm, 8mm and 10mm respectively, and the distance between the spray device 1 and the second end face of the battery cell 2 is 0mm, 3mm and 4mm respectively, the maximum temperature of the battery cell 2 adjacent to the out-of-control battery cell 2 can be effectively reduced, thereby suppressing the heat spread from the out-of-control battery cell 2 to the adjacent battery cell 2, ensuring the safety of the battery system, and avoiding the consequences of chain thermal runaway.

[0076] The present invention uses a spray device 1 made of composite materials through simulation calculation, and the effect comparison table of the spray device 1 and the aluminum alloy liquid cooling device is as follows:

[0077] Comparison table of charging effects between aluminum alloy liquid cooling device and spray device made of composite material of the present invention

[0078]

[0079]

[0080] The data in the charging effect comparison table of the aluminum alloy liquid cooling device and the spray device 1 made of the composite material of the present invention show that the spray device 1 made of the composite material provided by the present invention can achieve a fast charge of 628s to reach a range of 500km. Even compared with the traditional aluminum alloy cooling plate, the fast charging time of the battery pack of the spray device 1 made of the composite material is only extended by 12s, which is a small difference.

[0081] In some embodiments, the ratio of the cross-section of the spray device 1 to the capacity of the battery cell 2 is greater than 0.4 mm 2 / Ah, if the ratio of the cross section of the spray device 1 to the capacity of the battery cell 2 is too small, the cooling effect of the battery cell 2 will be poor. By limiting the ratio of the cross section of the spray device 1 to the capacity of the battery cell 2, the amount of cooling medium can be guaranteed to avoid the failure to achieve cooling effect on the battery cell 2 due to a small amount of cooling medium. In some examples, the ratio of the cross section of the spray device 1 to the capacity of the battery cell 2 is 0.7mm 2 / Ah, the cooling of the battery cell 2 is ensured under the premise that the cross section of the spray device 1 is not too large, thereby reducing the amount of cooling medium used. In some examples, the ratio of the cross section of the spray device 1 to the capacity of the battery cell 2 is 1.1mm 2 / Ah, which can increase the total amount of cooling medium for cooling the battery core 2 and improve the cooling effect.

[0082] In some embodiments, the spray device 1 includes a cooling medium, which is one of water, 50% ethylene glycol coolant, fluorinated liquid or R134a (1,1,1,2-tetrafluoroethane). In some examples, in order to reduce manufacturing costs, the cooling medium can be selected as water.

[0083] In some embodiments, one explosion-proof valve is provided with a corresponding spray device, and at least a portion of the spray device is located within the spray range of the explosion-proof valve, thereby achieving the purpose of spray cooling of the battery cell.

[0084] Since the projection of the spray device 1 provided in the embodiment of the present invention on the second end face does not overlap with the explosion-proof valve 4, in order to make the cooling and spraying of the battery cell 2 more uniform, in other embodiments of the present invention, one explosion-proof valve 4 is provided with two spray devices 1 to achieve the purpose of cooling the battery cell 2 with thermal runaway. The two spray devices 1 are provided to cool the battery cell 2 with thermal runaway, which can not only improve the efficiency of spraying and cooling the battery cell 2 with thermal runaway, but also increase the cooling area of ​​the battery cell 2 working normally, further improving the cooling effect. In addition, the interval between the spray device 1 that melts through first and the spray device 1 that melts through later is large, and the cooling medium will not be sprayed to the spray device 1 that melts through later, thereby ensuring the double spray cooling effect.

[0085] In some embodiments, there are multiple battery cells, multiple battery cells are arranged in an array and form at least one battery cell group arranged along a first direction, the spray device extends along the arrangement direction of the battery cell group, and the length of the spray device is greater than or equal to the total length of the multiple battery cells arranged in the first direction. In this way, it can be ensured that each battery cell can be arranged corresponding to the spray device, thereby reducing the number of spray devices arranged, while reducing the cost of the spray device arrangement, ensuring the relative position of the spray device and each battery cell, and thus ensuring that any battery cell can be sprayed and cooled in time after thermal runaway. For any battery cell, the projection of the spray device on the second end face does not overlap with the explosion-proof valve. It can be understood that the spray device completely avoids the explosion-proof valve arrangement of each battery cell, that is, the spray device and the explosion-proof valve of each battery cell are completely deviated from each other, so that the spray device can be melted through when the explosion-proof valve of any battery cell is opened and the cooling medium is sprayed to the explosion-proof valve.

[0086] In some embodiments, reference Figure 3 and Figure 4, when there are multiple battery cells 2, the first end face and the second end face of each battery cell 2 are arranged along the height direction of the battery cell 2, and the first end faces of the multiple battery cells 2 are arranged on the same side, and the second end faces of the multiple battery cells 2 are arranged on the same side. The spray device 1 is arranged along the arrangement direction of the battery cells 2, and two spray devices 1 are arranged on a row of battery cells 2, that is, a spray device 1 is arranged on both sides of each explosion-proof valve 4. It is assumed that the explosion-proof valves of the battery cells in the same battery pack have a first side and a second side, and the first side and the second side are arranged oppositely. When a spray device is correspondingly arranged for a row of battery cells, the spray devices of the two adjacent rows of battery cells are arranged on the first side of the explosion-proof valve, or the spray devices of the two adjacent rows of battery cells are arranged on the second side of the explosion-proof valve. In some examples, it can also be that in two adjacent columns of battery cells, the spray device corresponding to one column of battery cells is arranged on the first side of the explosion-proof valve, and the spray device corresponding to the other column of battery cells is arranged on the second side of the explosion-proof valve, so that the spray devices corresponding to different columns of battery cells are far away from or close to each other. When the spray devices corresponding to different columns of battery cells are far away from each other, it can be avoided that the spray devices corresponding to the adjacent columns of battery cells are melted through by the spray cooling medium due to heat transfer. When the spray devices corresponding to different columns of battery cells are close to each other, when any battery cell in one column of battery cells thermally runs away, the spray device corresponding to the other column of battery cells can block the heat emitted by the thermally runaway battery cell to avoid heat transfer to the other column of battery cells.

[0087] In some other embodiments, the first end face of each battery cell is arranged adjacent to the second end face, the first end faces of multiple battery cells are arranged on the same side, and the second end faces of multiple battery cells are arranged on the same side. In some examples, the second end faces of two adjacent columns of battery cells are arranged in the same plane, and the first end faces of two adjacent columns of battery cells are arranged in parallel, and the first end faces are all located on the same side of the second end face. Such an arrangement can prevent the explosion-proof valve of the second end face from spraying high-temperature substances to affect the battery cells in the adjacent columns. In some examples, two spray devices are arranged for each column of battery cells, and the two spray devices are arranged along the arrangement direction of the battery cells. In other embodiments, a spray device is arranged for each column of battery cells, and the explosion-proof valves of the battery cells in the same battery pack are set to have a first side and a second side, and the first side and the second side are arranged oppositely. When a spray device is correspondingly arranged for a column of battery cells, the spray devices of the two adjacent columns of battery cells are arranged on the first side of the explosion-proof valve, or the spray devices of the two adjacent columns of battery cells are arranged on the second side of the explosion-proof valve. In some examples, it can also be that in two adjacent columns of battery cells, the spray device corresponding to one column of battery cells is arranged on the first side of the explosion-proof valve, and the spray device corresponding to the other column of battery cells is arranged on the second side of the explosion-proof valve, so that the spray devices corresponding to different columns of battery cells are far away from or close to each other. When the spray devices corresponding to different columns of battery cells are far away from each other, it can be avoided that the spray devices corresponding to the adjacent columns of battery cells are melted through by the spray cooling medium due to heat transfer. When the spray devices corresponding to different columns of battery cells are close to each other, when any battery cell in one column of battery cells thermally runs away, the spray device corresponding to the other column of battery cells can block the heat emitted by the thermally runaway battery cell to avoid heat transfer to the other column of battery cells.

[0088] In some embodiments, Figure 3 and Figure 4 As shown, the first direction can be the width direction of the battery cell 2, the two spray devices 1 are arranged at intervals along the width direction of the battery cell 2, and the explosion-proof valve 4 is located between the two spray devices 1. The two spray devices 1 are arranged at intervals along the width direction of the battery cell 2. In this way, the length of the spray device 1 can be reduced, and the use cost of the spray device 1 can be reduced while ensuring that the battery cell 2 can be sprayed after thermal runaway.

[0089] The battery cell 2 also has a tab 3, wherein the tab 3 and the pole are located at the first end face of the battery cell 2, and each tab 3 is connected to the poles of two adjacent battery cells 2 to form a tab row. Specifically, the tab 3 is welded, screwed, riveted or bonded to the pole of the battery cell 2 with a conductive adhesive. For example, the tab 3 can be connected to the pole of the battery cell 2 by riveting or laser welding, so as to realize high-voltage series or parallel connection of the entire battery module. The tab 3 can be a copper alloy tab or an aluminum alloy tab, and an observation hole is provided on the tab 3. Furthermore, the tab 3 can be formed by stamping, machining or casting.

[0090] In the description of the present invention, reference is made to Figure 3 As shown, with the battery cell 2 stationary on the ground, the front and back are the stacking direction of the battery cell 2, and are also the width direction of the battery cell 2, that is, the first direction; the top and bottom are the height direction of the battery cell 2, that is, the second direction, and are also the direction perpendicular to the second end face, and the pole and the explosion-proof valve 4 are arranged along the second direction; the left and right are the length extension direction of the battery cell 2, that is, the third direction, and the two spray devices 1 are arranged at intervals along the third direction. The directional words disclosed in the present invention are only for the convenience of description and are not used to limit the specific direction of the battery module disclosed in the present invention.

[0091] Of course, in some other embodiments, the first direction may be the length direction of the battery cell 2, the two spray devices 1 are arranged at intervals along the length direction of the battery cell 2, and the explosion-proof valve 4 is located between the two spray devices 1. The two spray devices 1 are arranged at intervals along the length direction of the battery cell 2, which can increase the contact area between the battery cell 2 and the spray device 1, thereby improving the cooling effect on the non-thermal runaway battery cell 2. In addition, this arrangement can also make the explosion-proof valve 4 longer, thereby being able to release more high-temperature substances to increase the area of ​​the spray device 1 that is melted through. The increase in the melted through area can increase the total amount of cooling medium sprayed, thereby improving the cooling effect and response capability of the thermal runaway battery cell 2.

[0092] It should be noted that the projected length of the spray device 1 on the plane where the second end face is located should be greater than or equal to the total length of the multiple battery cells 2 arranged in the first direction. This can not only ensure that the spray device 1 cools the multiple battery cells 2, but also ensure that the spray device 1 is effectively connected to the current collector of the battery pack, and the current collector is connected to the liquid cooling circuit to distribute cooling medium to the spray device 1.

[0093] In some embodiments, each spray device 1 is provided with a weak area in the spray range corresponding to different battery cells 2 of the same battery cell group, so that it can be ensured that after any battery cell 2 of the same battery cell group goes into thermal runaway, the spray device 1 can be melted through to release the cooling medium and spray and cool down the battery cell 2 in thermal runaway. Of course, the spray device 1 can also be provided with a weak area in the non-spray range of multiple battery cells 2, so that no matter how the spray device 1 is installed, it can be ensured that the weak area is within the spray range, reducing the installation requirements for the spray device 1. When installing the spray device 1, it is not necessary to install it in a specified installation order, so as to avoid the spray device 1 being installed in the wrong position and unable to spray and cool the battery cell 2 in thermal runaway.

[0094] In some embodiments, the spray device 1 is a liquid cooling part made of composite materials, so that the overall performance of the spray device 1 tends to be consistent, and the spray device 1 may not be provided with a weak area, and the high-temperature substances sprayed out by the explosion-proof valves 4 corresponding to different battery cells 2 can more accurately and timely melt through the parts of the spray device 1 located within the spray range. The spray device 1 is simultaneously arranged at the bottom of different battery cells 2 in the same battery cell group, and the purpose of spraying and cooling after the thermal runaway battery cell 2 is accurately melted through can also be achieved.

[0095] In some embodiments, the liquid cooling element made of composite material may also be provided with a weak area to further improve the cooling response capability of the spray device 1 to the thermal runaway battery cell 2 .

[0096] In some embodiments, the spray device 1 is simultaneously attached to multiple battery cells 2 of the same battery cell group, so that the spray device 1 can simultaneously cool the surface of multiple battery cells 2 of the same battery cell group, and is easy to install and arrange. In other embodiments, the spray device 1 is simultaneously arranged at a certain distance from multiple battery cells 2, and each battery cell 2 is equidistant from the spray device 1, so that it is convenient to arrange the battery cells 2 and the spray device 1. Since the spray device 1 is a tube structure, the cooling effect of the battery cell 2 located upstream of the spray device 1 will be better than the cooling effect of the battery cell 2 located downstream of the spray device 1. When the battery cell 2 is arranged at a certain distance from the spray device 1, the problem of uneven cooling of the multiple battery cells 2 by the spray device 1 can be avoided. Of course, in other embodiments, the distances between the multiple battery cells 2 and the spray device 1 may not be equidistant, and can be set according to actual needs. In some other embodiments, the spray device 1 may be partially in contact with the battery cell 2, while the other part is set at a distance from the battery cell 2. In this way, it can be selectively set according to the actual needs of different battery cells 2. For example, in the upstream section of the spray device 1, the spray device 1 is set at a certain distance from the battery cell 2, and in the downstream section of the spray device 1, the spray device 1 is in contact with the battery cell 2, thereby adaptively cooling each battery cell 2 locally, so that the battery cell 2 can be cooled while preventing the battery cell 2 from overheating and causing the temperature of the cooling medium to rise to a high level.

[0097] An embodiment of the present invention further provides a battery pack, such as Figure 5 As shown, the battery pack includes a shell 6, and a plurality of battery modules provided by the above embodiments are arranged inside the shell 6.

[0098] When the spray device is fitted with the second end face of the battery cell, for a battery cell group having multiple battery cells, each battery cell is fitted with the spray device, and the accommodating cavity formed by the shell is relative to the inner wall of the explosion-proof valve and the opposite side walls of the two liquid cooling parts to jointly enclose the exhaust channel corresponding to the explosion-proof valve. Compared with the prior art that requires additional grooves, the battery pack provided by the present invention does not require additional grooves, and only needs to be formed by the spray device and the shell 6 that are arranged at intervals. This reduces the requirements for the side wall thickness of the shell 6, so that the battery pack as a whole can be more compact. In addition, there is no need to process additional grooves on the shell 6, which can reduce processing costs and processing difficulties.

[0099] In some embodiments, Figure 6 and Figure 7As shown, a buffer layer 5 is filled between the spray device 1 and the inner wall of the shell 6, and the inner wall of the accommodating cavity opposite to the explosion-proof valve 4, the side walls opposite to the two buffer layers 5, and the side walls opposite to the two spray devices 1 together enclose the exhaust channel 7. The buffer layer 5 can absorb the impact energy in the vibration and play a role in protecting the battery cell 2. In some embodiments, the buffer layer 5 is a foam layer. Since foam is easy to obtain, the manufacturing difficulty and manufacturing cost are reduced. In some embodiments, the buffer layer 5 can be a silicone foam layer, a melamine foam layer, a polyurethane foam layer, etc.

[0100] When the shell 6 is impacted by the outside, a force acts on the shell 6 and is buffered by the buffer layer 5, thereby weakening the impact effect of the force, thereby protecting the explosion-proof valve 4 and protecting the entire battery pack.

[0101] In some embodiments, continue to refer to Figure 6 , the width of the buffer layer 5 is w1, and the width of the spray device 1 is w2, wherein 0.1≤w1 / w2≤10. In some embodiments, the value of w1 / w2 is 0.1, 5 or 10, which is not specifically limited herein. It can be seen from the value of w1 / w2 that the width of the buffer layer 5 can be smaller than the width of the spray device 1 or larger than the width of the spray device 1, but it needs to be ensured that the buffer layer 5 can isolate the spray device 1 from the inner wall of the accommodating cavity, and the buffer layer 5 can absorb the impact energy in the vibration. When the value of w1 / w2 is 0.1, the width of the spray device 1 is much larger than the width of the buffer layer 5, thereby reducing the manufacturing cost while absorbing the vibration impact energy. When the value of w1 / w2 is 5, the width of the spray device 1 is smaller than the width of the buffer layer 5, thereby preventing the buffer layer 5 from being burned by high-temperature substances and causing the battery cell 2 to have no buffer protection. When the value of w1 / w2 is 10, it indicates that the width of the buffer layer 5 is large enough, so that the battery cell 2 in the housing 6 can be fully protected, and the battery cell 2 can be prevented from being damaged due to vibration impact at the weaker position of the battery cell 2, thereby improving the safety of the battery cell 2.

[0102] In some embodiments, the thickness of the buffer layer 5 is D, where 0mm<D≤10mm. In some embodiments, the thickness D of the buffer layer 5 is 1mm, 6mm or 10mm, which is not specifically limited here. The buffer layer 5 has a small thickness, and can play a buffering role without taking up much height space of the battery pack. In some embodiments, when the thickness D of the buffer layer 5 is 1mm, it can reduce the volume of the space where the battery pack is located and play a good buffering role. When the thickness of the buffer layer 5 is 10mm, it can increase the protection of the battery cell 2 on the basis of buffering, so that more vibration impact energy can be absorbed. When the thickness of the buffer layer 5 is 6mm, it can reduce the overall space of the battery pack while absorbing more vibration impact energy.

[0103] In some embodiments, a fireproof layer (not shown in the figure) is provided on the inner wall of the shell 6 facing the first end surface, and the fireproof layer can prevent thermal runaway from damaging the shell 6 of the battery pack when thermal runaway occurs in the battery cell 2.

[0104] In some embodiments, the fireproof layer is a mica plate, a ceramic composite tape, a ceramic silicone rubber spray layer, a tungsten carbide spray layer, a chromium carbide spray layer, a ceramic organic hybrid material spray layer, a steel sheet, an aluminum alloy layer, or a glass fiber composite layer or a carbon fiber composite layer. All of the above fireproof layers can achieve the purpose of fireproofing.

[0105] In some embodiments, continue to refer to Figure 6 , the distance between the opposite side walls of the two spray devices 1 is w3, and the length of the battery cell 2 is w4, wherein 0.1≤w3 / w4≤0.8. In some embodiments, the ratio of w3 / w4 may be 0.1, 0.5 or 0.8. When w3 / w4 is 0.1, the width of the exhaust channel 7 is small, which can ensure that the high-temperature substances in the exhaust channel 7 can be discharged smoothly. When the ratio of w3 / w4 is 0.5, while ensuring that the high-temperature substances can be discharged smoothly, it can also prevent the high-temperature substances from adhering to the exhaust channel 7 and causing the exhaust channel 7 to be easily blocked. In addition, it can also avoid the interference of the ratio being too large with other structures of the battery cell 2 (such as the pole 5). When the ratio of w3 / w4 is 0.8, the exhaust channel 7 is wide, which can provide more accommodation space for high-temperature substances, prevent the high-temperature substances from gathering inside and outside the explosion-proof valve 4 of the battery cell 2 and affecting the overall structure of the battery cell 2. In addition, it can also avoid the interference of the ratio being too large with other structures of the battery cell 2 (such as the pole 5).

[0106] In some embodiments, the inner wall of the shell 6 facing the explosion-proof valve 4 is the first inner wall, and the distance between the first inner wall and the explosion-proof valve 4 is 6mm to 20mm. In some embodiments, the distance between the first inner wall and the explosion-proof valve 4 is 6mm, 13mm or 20mm. When the distance between the first inner wall and the explosion-proof valve 4 is 6mm, the overall space requirement of the battery pack is low while ensuring the formation of the exhaust channel 7. When the distance between the first inner wall and the explosion-proof valve 4 is 13mm, the thickness requirements of the spray device 1 and the buffer layer 5 are reduced, thereby ensuring that the flow rate of the cooling medium per unit time of the spray device 1 increases, ensuring the cooling of the surface of the battery cell 2, and absorbing more vibration impact energy. When the distance between the first inner wall and the explosion-proof valve 4 is 20mm, the height of the exhaust channel 7 can be guaranteed to be higher, the volume of the exhaust channel 7 can be increased, and the exhaust capacity of the exhaust channel 7 can be guaranteed.

[0107] Continue to refer Figure 6A current collector 8 is also provided in the shell 6. The current collector 8 is connected to each spray device 1. The current collector 8 is connected to a liquid cooling circuit. The liquid cooling circuit provides a circulating cooling medium for the current collector 8. The current collector 8 is used to distribute the cooling medium to each spray device 1.

[0108] Since the battery pack according to the embodiment of the present invention includes the above-mentioned battery module, the battery pack has all the advantages and beneficial effects of the above-mentioned embodiments, which will not be described in detail here.

[0109] The embodiments of the present invention further provide a vehicle, in some embodiments, the vehicle is an electric vehicle or a hybrid vehicle, and the vehicle comprises a vehicle body and a power battery pack provided in the above embodiments, the power battery pack is arranged on the vehicle body, and the vehicle body provides support for the battery module.

[0110] Since the vehicle of the embodiment of the present invention includes the above-mentioned battery pack, it has all the advantages and beneficial effects of the above-mentioned embodiments, which will not be described in detail here.

[0111] It should be noted that the battery pack disclosed in the present invention can be used not only in vehicles, but also in ships or other mechanical devices.

[0112] In addition, the above are only preferred embodiments of the present invention and the technical principles used. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and that various obvious changes, readjustments and substitutions can be made by those skilled in the art without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in more detail through the above embodiments, the present invention is not limited to the above embodiments, and may include more other equivalent embodiments without departing from the concept of the present invention, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. A battery module, characterized in that: include: A battery cell (2), the battery cell (2) having a first end face and a second end face, a pole of the battery cell (2) being located on the first end face, and an explosion-proof valve (4) of the battery cell (2) being located on the second end face; A spray device (1), arranged relative to the second end surface; The projection of the spray device (1) on the second end surface does not overlap with the explosion-proof valve (4), and at least part of the spray device (1) is located within the spraying range of the explosion-proof valve (4).

2. The battery module according to claim 1, characterized in that: The portion of the spray device (1) located within the spraying range is provided with a weak area; And / or, the spray device (1) is a liquid cooling component made of a composite material.

3. The battery module according to claim 2, characterized in that: The melting point of the meltable portion of the spray device (1) is ≤ 400° C.; and / or, The wall thickness of the meltable portion is 0.1 mm to 2 mm.

4. The battery module according to claim 2, characterized in that: The liquid cooling component is in communication with a liquid cooling circuit, and at least a portion of an outer wall of the liquid cooling component is in contact with the second end surface.

5. The battery module according to claim 1, characterized in that: In a direction perpendicular to the second end face, the distance between the spray device (1) and the second end face is 0 to 20 mm; and / or, The offset between the projection of the spray device (1) on the second end surface and the explosion-proof valve (4) is 0 to 30 mm.

6. The battery module according to claim 1, characterized in that: The ratio of the cross-sectional area of ​​the spray device (1) to the capacity of the battery core (2) is greater than 0.4 mm 2 / Ah.

7. The battery module according to any one of claims 1 to 6, characterized in that: The number of the battery cells (2) is multiple, the multiple battery cells (2) are arranged in an array and form at least one battery cell group arranged along a first direction, the spray device (1) extends along the arrangement direction of the battery cell group, and the length of the spray device (1) is greater than or equal to the total length of the multiple battery cells (2) arranged in the first direction.

8. The battery module according to claim 7, characterized in that: The first direction is the width direction of the battery core (2), the two spray devices (1) are arranged at intervals along the width direction of the battery core (2), and the explosion-proof valve (4) is located between the two spray devices (1); Alternatively, the first direction is the length direction of the battery cell (2), the two spray devices (1) are arranged at intervals along the length direction of the battery cell (2), and the explosion-proof valve (4) is located between the two spray devices (1).

9. A battery pack, comprising a battery box, characterized in that: A plurality of battery modules according to any one of claims 1 to 8 are arranged in the battery box.

10. A vehicle, comprising a vehicle body, characterized in that: Comprising the battery pack as claimed in claim 9, wherein the battery pack is arranged on the vehicle body.

Images