Battery pack and vehicle

Abstract

The invention relates to the technical field of vehicles, in particular to a battery pack and a vehicle. The battery comprises a shell, a battery cell and a liquid cooling structure, the shell is provided with a containing cavity, the battery cell is located in the containing cavity, an anti-explosion valve of the battery cell is located on the first end face of the battery cell, the liquid cooling structure comprises two cooling parts, and the two cooling parts are attached to the first end face and arranged on the two sides of the anti-explosion valve at intervals; an exhaust channel corresponding to the anti-explosion valve is jointly defined by the inner wall, opposite to the anti-explosion valve, of the containing cavity and the side walls, opposite to the two cooling pieces, of the two cooling pieces. Compared with the prior art that a groove needs to be additionally arranged, the battery pack provided by the invention does not need to be additionally provided with the groove, and the battery pack can be formed by jointly enclosing the cooling pieces and the shell which are arranged at intervals, so that the requirement on the thickness of the side wall of the shell is reduced, and the whole battery pack can be more compact; a groove does not need to be additionally machined in the shell, and the machining cost and machining difficulty can be reduced.

Description

Technical Field

[0001] The present invention relates to the field of vehicle technology, and in particular to 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 cooling medium is generally used to spray thermal runaway cells, so as to cool the runaway cells and their adjacent cells and prevent the thermal runaway from spreading. However, after the high-temperature material is released through the explosion-proof valve, the high-temperature material needs to be discharged from the casing as soon as possible. For this reason, in the related art, a groove is usually opened in the casing facing the explosion-proof valve to discharge the high-temperature material through the groove. Since the groove has a certain depth requirement, this leads to an increase in the thickness of the casing wall, which also increases the difficulty and cost of processing the casing.

[0004] Therefore, there is an urgent need for a battery pack to solve the above technical problems. Summary of the invention

[0005] The object of the present invention is to provide a battery pack and a vehicle, which can form an exhaust channel to guide high-temperature substances.

[0006] To achieve this object, the present invention adopts the following technical solutions:

[0007] A battery pack is provided, comprising:

[0008] A housing having a receiving cavity;

[0009] A battery cell, the battery cell is located in the accommodating cavity, and a first end surface of the battery cell is provided with an explosion-proof valve;

[0010] A liquid cooling structure, the liquid cooling structure comprising two cooling members, the two cooling members are respectively arranged in contact with the first end surface and are arranged at intervals on both sides of the explosion-proof valve;

[0011] The inner wall of the accommodating cavity opposite to the explosion-proof valve and the side walls opposite to the two cooling components together enclose an exhaust passage corresponding to the explosion-proof valve.

[0012] As a preferred technical solution for the above-mentioned battery pack, the projection of the cooling member on the first end face does not overlap with the explosion-proof valve, at least part of the cooling member is located within the spray range of the explosion-proof valve, and the portion of the cooling member located within the spray range of the explosion-proof valve can be melted through by the high-temperature material sprayed from the battery cell in thermal runaway.

[0013] As a preferred technical solution of the above battery pack, a portion of the cooling member located within the injection range of the explosion-proof valve is provided with a weak area; and / or,

[0014] The cooling element is a liquid cooling element made of composite material.

[0015] As a preferred technical solution for the above-mentioned battery pack, a buffer layer is filled between the cooling element and the inner wall of the outer shell, and the inner wall of the accommodating cavity opposite to the explosion-proof valve, the side walls opposite to the two buffer layers and the side walls opposite to the two cooling elements together enclose the exhaust channel.

[0016] As a preferred technical solution of the above battery pack, the width of the buffer layer is w1, the width of the cooling member is w2, wherein 0.1≤w1 / w2≤10; and / or,

[0017] The thickness of the buffer layer is D, wherein 0mm<D≤10mm.

[0018] As a preferred technical solution of the above-mentioned battery pack, a fireproof layer is provided on the inner wall of the outer shell facing the first end surface.

[0019] As a preferred technical solution of the above battery pack, the distance between the two opposite side walls of the cooling member is w3, the length of the battery cell is w4, wherein 0.1≤w3 / w4≤0.8;

[0020] And / or, the inner wall of the shell facing the explosion-proof valve is a first inner wall, and the distance between the first inner wall and the explosion-proof valve is 6 mm to 20 mm.

[0021] As a preferred technical solution for the above-mentioned battery pack, 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 cooling member extends along the arrangement direction of the battery cell group, and the length of the cooling member is greater than or equal to the total length of the multiple battery cells arranged in the first direction.

[0022] As a preferred technical solution of the above-mentioned battery pack, the shell is provided with an exhaust port, and the exhaust port is connected to the exhaust channel.

[0023] The present invention also provides a vehicle, comprising a vehicle body and any one of the above-mentioned battery packs, wherein the battery pack is arranged on the vehicle body.

[0024] The present invention has at least the following beneficial effects:

[0025] The battery pack and vehicle provided by the present invention have two cooling members, and the cooling members are fitted with the first end face of the battery cell, so that the inner wall of the accommodating cavity opposite to the explosion-proof valve and the side walls opposite to the two cooling members jointly form an exhaust channel. Compared with the prior art that requires additional grooves to be arranged, the battery pack provided by the present invention does not require additional grooves, and only needs to be formed by the cooling members and the outer shell arranged at intervals. This reduces the requirements for the thickness of the side walls of the outer shell, so that the battery pack as a whole is more compact. In addition, there is no need to additionally process grooves on the outer shell, which can reduce processing costs and processing difficulty. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] 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.

[0027] Figure 1 Schematic diagram of the positional relationship between the cooling element and the battery cell provided in an embodiment of the present invention Figure 1 ;

[0028] Figure 2 Schematic diagram of the positional relationship between the cooling element and the battery cell provided in an embodiment of the present invention Figure 2 ;

[0029] Figure 3 Schematic diagram of the positional relationship between the cooling element and the battery cell provided in an embodiment of the present invention Figure 3 ;

[0030] Figure 4 A cross-sectional view of a battery pack provided by an embodiment of the present invention Figure 1 ;

[0031] Figure 5 A cross-sectional view of a battery pack provided by an embodiment of the present invention Figure 2 ;

[0032] Figure 6 Schematic diagram of the structure of the battery cell provided in the embodiment of the present invention Figure 1 ;

[0033] Figure 7 Schematic diagram of the structure of the battery cell provided in the embodiment of the present invention Figure 2 ;

[0034] Figure 8 An exploded schematic diagram of a battery pack provided in an embodiment of the present invention;

[0035] Fig. 9 An exploded schematic diagram of a housing provided in an embodiment of the present invention.

[0036] In the figure:

[0037] 1. Outer shell; 11. First shell; 12. Second shell; 2. Battery cell; 3. Explosion-proof valve; 4. Cooling element; 5. Pole; 6. Buffer layer; 7. Bar; 8. Exhaust channel; 9. Current collector. DETAILED DESCRIPTION

[0038] 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.

[0039] 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.

[0040] 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.

[0041] 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.

[0042] The present invention is based on the inventor's discovery and understanding of the following facts and problems:

[0043] In the related art, after thermal runaway occurs in the battery cell, the high-temperature substance dissipates through the explosion-proof valve of the battery cell. The high-temperature substance needs to be discharged from the outer casing as soon as possible. For this purpose, in the related art, a groove is usually opened in the position of the outer casing facing the explosion-proof valve or a diversion structure for diverting the high-temperature substance is set to discharge the high-temperature substance through the groove or the diversion structure.

[0044] However, the related technology has the following defects: the groove has a certain depth requirement, which leads to an increase in the wall thickness of the shell, and the guide structure occupies the accommodating cavity space formed by the shell, which in turn causes the overall space requirement of the battery pack to increase.

[0045] To this end, the inventor considered solving the above technical problems by adjusting the existing structure without increasing the current battery pack space requirements. After continuous efforts by the inventor, the inventor formed an exhaust channel through two spaced-apart liquid cooling parts and a shell to guide the high-temperature medium.

[0046] In addition, the explosion-proof valve sprays high-temperature materials 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 if two spray devices are set at least partially opposite each other, the spray device that melts through first will spray and cool down the spray device that melts through later, thereby hindering the melting of the spray device that melts through later, and the cooling effect is poor. For this reason, the relevant technology adopts a method in which a spray device and the explosion-proof valve are at least partially opposite each other to ensure that the spray device can be melted through, thereby ignoring the scheme of setting two spray devices, and no further research is conducted on the staggered arrangement of the spray device and the explosion-proof valve.

[0047] Since both the spray device and the liquid cooling structure are used to cool the battery cells, the inventors considered combining the spray device with the liquid cooling structure.

[0048] Therefore, the present invention conducts multiple tests and studies on the positional relationship between the spray device and the explosion-proof valve, and confirms the positional relationship between the three when the spray device is melted through when the battery cell has thermal runaway.

[0049] The inventors have obtained the battery pack provided by the present invention through continuous efforts. When one of the battery cells has thermal runaway, the two opposite side walls of the cooling parts and the inner wall of the shell facing the explosion-proof valve together form an exhaust channel, so that the high-temperature substances ejected from the battery cell in thermal runaway can be dispersed out of the battery pack along the extension direction of the exhaust channel, reducing the processing cost and difficulty of the shell without increasing the space requirements of the battery pack. It is further defined that the projection of the cooling part on the end face where the explosion-proof valve is located does not overlap with the explosion-proof valve, and the cooling part is located within the spray range of the explosion-proof valve. The part of the cooling part located within the spray range of the explosion-proof valve can be melted through by the high-temperature substances ejected from the battery cell in thermal runaway. Since the cooling part that melts through first will not affect the melting through of the other cooling part, the above-mentioned technical prejudice of those skilled in the art that the cooling effect is poor when two spray devices are provided is effectively overcome.

[0050] To this end, an embodiment of the present invention provides a battery pack that can form an exhaust channel to guide high-temperature substances without separately providing a groove.

[0051] A battery pack is provided in an embodiment of the present invention, comprising a shell, a liquid cooling structure and a battery cell, wherein the liquid cooling structure and the battery cell are arranged in a accommodating cavity formed by the shell, an explosion-proof valve is arranged on the first end surface of the battery cell, and the liquid cooling structure comprises two cooling members, which are respectively arranged in contact with the first end surface, and the two cooling members are arranged on both sides of the explosion-proof valve, and the inner wall of the accommodating cavity opposite to the explosion-proof valve and the side walls opposite to the two cooling members jointly enclose an exhaust channel corresponding to the explosion-proof valve.

[0052] The liquid cooling structure includes two cooling elements, and the cooling elements can cool the battery cells. The cooling elements are fitted to the first end faces of the battery cells, so that the inner wall of the accommodating cavity opposite to the explosion-proof valve and the side walls opposite to the two cooling elements together form an exhaust channel. Compared with the prior art that requires additional grooves, the battery pack provided by the present invention does not require additional grooves, but only needs to be formed by the cooling elements and the outer shell that are arranged at intervals. This reduces the requirements for the side wall thickness of the outer shell, so that the battery pack as a whole can be more compact. In addition, there is no need to additionally process grooves on the outer shell, which can reduce processing costs and processing difficulty.

[0053] In some embodiments, the cooling member extends along the length direction or width direction of the battery cell, so that two cooling members form an exhaust channel along the length direction or width direction of the battery cell. When the cooling member extends along the length direction of the battery cell, a larger area of ​​the battery cell can be attached to the cooling member, thereby improving the overall cooling ability of the cooling member on the battery cell. When the cooling member extends along the width direction of the battery cell, more battery cells can be cooled.

[0054] Considering that the cooling element can spray and cool down the battery cell in thermal runaway when it is melted through, but the cooling element cannot be melted through by the high-temperature material sprayed from the battery cell in thermal runaway at all positions, the present invention has confirmed the spray range of the explosion-proof valve that can melt through the cooling element when the battery cell is in thermal runaway by conducting multiple tests and studies on the positional relationship between the cooling element and the explosion-proof valve, wherein the spray range is specifically the area range where the high-temperature material actually passes through and the area range where the high-temperature material can effectively melt through at least part of the cooling element by heat transfer. The cooling element 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 thermal radiation, heat conduction, and heat convection). This effectively overcomes the technical prejudice mentioned above by those skilled in the art that the spray device cannot effectively melt through the spray device when the projection of the end face where the explosion-proof valve is located does not overlap with the explosion-proof valve.

[0055] In some embodiments, along a direction perpendicular to the first end surface, such as Figure 1-Figure 3 As shown, the projection of the cooling member 4 on the first end face does not overlap with the explosion-proof valve 3, and at least part of the cooling member 4 is located within the spray range of the explosion-proof valve 3, and the portion of the cooling member 4 located within the spray range of the explosion-proof valve 3 can be melted through by the high-temperature material sprayed from the thermal runaway battery cell 2. The fact that the projection of the cooling member 4 on the first end face does not overlap with the explosion-proof valve 3 can be understood as the cooling member 4 and the explosion-proof valve 3 being arranged in a avoided manner, so that the cooling member 4 and the explosion-proof valve 3 are at least partially arranged opposite to each other, causing the cooling member 4 to hinder the opening of the explosion-proof valve 3. Such an arrangement can ensure that the high-temperature material in the battery cell 2 can flow out of the battery cell 2 smoothly, so as to prevent the internal pressure of the thermal runaway battery cell 2 from continuing to rise, and avoid structural failure of the battery cell 2.

[0056] It can be understood that the positive projection of the cooling member 4 on the first end face does not overlap with the explosion-proof valve 3, which can effectively prevent the cooling member from hindering the smooth opening of the explosion-proof valve 3, and at the same time prevent high-temperature substances from being reflected by the surface of the cooling member 4 and splashing back to the position of the explosion-proof valve 3, causing subsequent high-temperature substances to fail to be sprayed out in time.

[0057] The cooling element 4 can be completely located within the spray range of the explosion-proof valve 3, or it can be partially located within the spray range of the explosion-proof valve 3. Such a setting can ensure that the cooling element 4 can cool down the high-temperature substances in the exhaust channel 8 more, and can also reduce the temperature in the exhaust channel 8 while cooling the battery cell 2.

[0058] In some embodiments, Figure 3As shown, along the direction perpendicular to the first end face, the offset between the projection of the cooling member 4 on the first end face and the explosion-proof valve 3 is 0 to 30 mm. Optionally, the offset between the projection of the cooling member 4 on the first end face and the explosion-proof valve 3 is 0 mm, 1 mm, 10 mm or 30 mm, which is not specifically limited here. If the offset between the projection of the cooling member 4 on the first end face and the explosion-proof valve 3 is 0 mm, it can ensure that the position of the cooling member 4 close to the explosion-proof valve 3 is melted through as soon as possible, so that the cooling medium is sprayed out to improve the ability of the cooling member 4 to cope with thermal runaway cells. If the offset between the projection of the cooling member 4 on the first end face and the explosion-proof valve 3 is 1 mm, it can ensure that the spray device does not contact the explosion-proof valve 3, avoiding being melted through by the high-temperature explosion-proof valve 3 without spraying. When the projection of the cooling element 4 on the first end face and the offset of the explosion-proof valve 3 are 10mm, it is possible to avoid the temperature of the explosion-proof valve 3 being higher than the temperature of other positions of the battery cell 2, and the higher heat radiation to the cooling element 4 causing the cooling element 4 to be melted through by mistake. At the same time, it is also possible to ensure that the cooling element 4 and the explosion-proof valve 3 are within the optimal spray range of each other. When the projection of the cooling element 4 on the first end face and the offset of the explosion-proof valve 3 are 30mm, it is possible to ensure that the spray range of the cooling element 4 is larger, and it is possible to ensure that the high-temperature area can be sprayed and cooled more. Through the above-mentioned structural design, since the offset of the projection of the cooling element 4 and the explosion-proof valve 3 is small, the cooling element 4 is more easily melted by the high-temperature material sprayed from the explosion-proof valve 3, thereby further ensuring that the battery pack has a better ability to cope with thermal runaway.

[0059] In some embodiments, a portion of the cooling member 4 within the spraying range is provided with a weak zone, wherein the wall thickness of the weak zone is thinner than that of other positions of the cooling member 4, so that it can be easily melted through. Such a setting can avoid heat spread caused by untimely spraying.

[0060] In some embodiments, the cooling member 4 is a metal material member, for example, the cooling member 4 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 2. The cooling member 4 made of metal material is located in the injection range of the explosion-proof valve 3 and is provided with a weak area, so that it is easy to be melted through.

[0061] 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 set toward the explosion-proof valve 3, 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 set toward the explosion-proof valve 3 to improve the melting rate of the cooling part 4.

[0062] In some embodiments, the cooling element 4 may also be a liquid cooling element made of a composite material. The liquid cooling element 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 cooling medium is sprayed out after being melted to achieve the purpose of cooling. In some embodiments, the cooling element 4 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 cooling element 4. In some examples, the composite material may be nylon, polyphenylene ether, polypropylene or polycarbonate.

[0063] Since the cooling member 4 is made of a composite material, the overall performance tends to be consistent. In some embodiments, the cooling member 4 is a liquid-cooled member with the same wall thickness throughout, that is, the cooling member 4 is not provided with a weak area, and the high-temperature material sprayed out by the explosion-proof valve 3 can more accurately and timely melt through the portion of the cooling member 4 within the spraying range.

[0064] 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 3, thereby improving the response capability of the liquid cooling component to the thermal runaway battery cell 2.

[0065] 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 2 that is working normally. When the cooling member 4 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 member made of the composite material on the battery cell 2 being poorer than the cooling effect of the liquid cooling member 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, and can be specifically 0.5W / m·K, 0.7W / m·K / , 1.1W / m·K / or higher. In some examples, the thermal conductivity may be 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 sprayed can be quickly reduced, thereby improving the cooling effect. For example, the composite material is nylon. In some examples, the thermal conductivity may be 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 may 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.

[0066] Since the temperature of the high-temperature material sprayed from the explosion-proof valve 3 is greater than 500°C, when the melting point of the meltable part of the cooling member 4 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 meltable part of the cooling member 4 is less than or equal to 400°C, and the meltable part is a position where the high-temperature material can be melted after being sprayed onto the cooling member 4. For example, the meltable 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 meltable part can ensure that the cooling member 4 can melt quickly in a high-temperature environment to ensure that the cooling medium is sprayed from the cooling member 4. When the melting point of the meltable part is less than or equal to 400°C, since the melting point of the meltable part is much lower than the temperature of the high-temperature material, the meltable part can be melted after the high-temperature material is sprayed on the meltable part, and the melting response speed is fast, which prevents the high-temperature material from accumulating around the explosion-proof valve 3 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 cooling member 4 can be melted through relatively quickly, so that the cooling medium can be 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 prevent the ambient temperature from rising after the 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 spray and cool the battery cell 2 that has experienced thermal runaway, further preventing heat spread. For example, the composite material can be nylon.

[0067] 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 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 cooling element from being used again when the battery cell 2 actually has 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 coolable element 4. When the wall thickness of the meltable part is 2 mm, the wall thickness of other parts of the cooling element 4 is thicker, which can improve the overall strength of the cooling element 4, prevent the cooling element 4 from being damaged after being impacted, and ensure that the cooling element 4 is melted. The above-mentioned wall thickness limitation can prevent the cooling element 4 from melting for a long time in the spraying range, and the melting gap becomes smaller and the cooling medium cannot be sprayed in time.

[0068] From the comparison table of the effects of the cooling element 4 made of an aluminum alloy liquid cooling device and a composite material, it can be seen that: when the cooling element 4 and the explosion-proof valve 3 are offset (when the offset between the projection of the cooling element 4 on the first end face and the explosion-proof valve 3 is 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.

[0069] Comparison table of cooling effects between aluminum alloy liquid cooling devices and cooling parts made of composite materials

[0070]

[0071] From the comparison table of the effects of the aluminum alloy liquid cooling device and the cooling member 4 made of composite materials, it can be seen that when the cooling member 4 made of composite materials is used, when the projection offset between the explosion-proof valve 3 and the cooling member 4 is 1mm, 8mm and 10mm respectively, and the distance between the cooling member 4 and the first 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.

[0072] Through simulation calculation, the present invention compares the charging effect of the cooling member made of the composite material provided by the present invention with that of the aluminum alloy cooling plate as follows:

[0073] Comparison table of charging effects of aluminum alloy cooling plate and cooling member made of composite material of the present invention

[0074]

[0075] The data in the charging effect comparison table of the aluminum alloy liquid cooling device and the cooling piece made of the composite material of the present invention show that the cooling piece made of the composite material provided by the present invention can achieve the ability of fast charging in 628s to reach a range of 500km. Even compared with the traditional aluminum alloy cooling plate, the fast charging time of the battery pack using the cooling piece made of the composite material is only extended by 12s, which is a small difference.

[0076] In some embodiments, a heat-conducting layer is provided between the cooling member 4 and the second end face, and the provision of the heat-conducting layer can facilitate the conduction of heat of the battery cell 2, and the cooling member 4 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 mm 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 2 can be quickly transferred to the cooling member 4, and when the thickness of the heat-conducting layer is 1 mm, the cooling member 4 and the battery cell 2 can have a good heat-conducting effect, and the cooling member 4 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 also enabling the cooling member 4 to maintain a certain temperature to meet the cooling requirements of the thermal runaway battery cell 2.

[0077] In some embodiments, the ratio of the cross section of the cooling member 4 to the capacity of the battery cell 2 is greater than 0.4mm2 / Ah. If the ratio of the cross section of the cooling member 4 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 cooling member 4 to the capacity of the battery cell 2, the amount of cooling medium can be guaranteed, and the cooling effect of the battery cell 2 cannot be achieved due to the small amount of cooling medium. In some examples, the ratio of the cross section of the cooling member 4 to the capacity of the battery cell 2 is 0.7mm2 / Ah, which ensures the cooling of the battery cell 2 while ensuring that the cross section of the cooling member 4 is not too large, thereby reducing the amount of cooling medium used. In some examples, the ratio of the cross section of the cooling member 4 to the capacity of the battery cell 2 is 1.1mm2 / Ah, which can increase the total amount of cooling medium for cooling the battery cell 2 and improve the cooling effect.

[0078] In some embodiments, the cooling member 4 is connected to the liquid cooling circuit, and at least part of the outer wall of the cooling member 4 is in contact with the first end face. If at least part of the outer wall of the liquid cooling member is in contact with the first end face, it means that part of the outer wall of the cooling member 4 facing the first end face is in contact with the first end face or all the side walls of the cooling member 4 facing the first end face are in contact with the first end face. The contact of the liquid cooling member with the first end face can cool the first end face. Since the liquid cooling circuit is connected to the cooling member 4, the liquid cooling circuit can provide a circulating cooling medium for the cooling member 4, thereby ensuring that the cooling medium entering the cooling member 4 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 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.

[0079] In some embodiments, reference Figure 4A current collector 9 is also provided in the housing 1 . The current collector 9 is connected to each cooling element 4 . The current collector 9 is connected to a liquid cooling circuit. The liquid cooling circuit provides a circulating cooling medium for the current collector 9 . The current collector 9 is used to distribute the cooling medium to each cooling element 4 .

[0080] In some embodiments, the cooling member 4 may be a harmonica tube, which is at least arranged on one side of the explosion-proof valve 3 and is in contact with the first end face. When the battery cell 2 fails due to thermal failure, high-temperature substances are ejected from the explosion-proof valve 3. Since the cooling member 4 is arranged close to the explosion-proof valve 3, the high-temperature substances can melt through the cooling member 4, so that the cooling medium in the harmonica tube is sprayed onto the battery cell 2 that has thermal runaway and the surface of the surrounding battery cells 2. After the cooling medium flows out from the part where the cooling member is melted through, 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 2 that have not experienced thermal runaway, thereby achieving the purpose of cooling from different positions of the battery cell 2.

[0081] Since the cooling member 4 is specifically a harmonica tube, the cooling area of ​​the cooling member 4 for cooling the battery cell 2 can be increased, so that the cooling member 4 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 cooling member 4 can also be a liquid cooling plate.

[0082] In some embodiments, Figure 4 and Figure 5 As shown, a buffer layer 6 is filled between the cooling member 4 and the inner wall of the housing 1, and the inner wall of the accommodating cavity opposite to the explosion-proof valve 3, the side walls opposite to the two buffer layers 6, and the side walls opposite to the two cooling members 4 together enclose an exhaust channel 8. The buffer layer 6 can absorb the impact energy in the vibration and play a role in protecting the battery core 2. In some embodiments, the buffer layer 6 is a foam layer. Since foam is easy to obtain, the manufacturing difficulty and manufacturing cost are reduced. In some embodiments, the buffer layer 6 can be a silicone foam layer, a melamine foam layer, a polyurethane foam layer, etc.

[0083] When the shell 1 is impacted by the outside, the force acts on the shell 1 and is buffered by the buffer layer 6, thereby weakening the impact effect of the force, thereby protecting the explosion-proof valve 3 and the entire battery pack.

[0084] In some embodiments, continue to refer to Figure 1, the width of the buffer layer 6 is w1, and the width of the cooling element 4 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 6 can be smaller than the width of the cooling element 4 or larger than the width of the cooling element 4, but it needs to be ensured that the buffer layer 6 can isolate the cooling element 4 from the inner wall of the accommodating cavity, and the buffer layer 6 can absorb the impact energy in the vibration. When the value of w1 / w2 is 0.1, the width of the cooling element 4 is much larger than the width of the buffer layer 6, thereby reducing the manufacturing cost while absorbing the vibration impact energy. When the value of w1 / w2 is 5, the width of the cooling element 4 is smaller than the width of the buffer layer 6, thereby preventing the buffer layer 6 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 6 is large enough, so that the battery cell 2 in the housing 1 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.

[0085] In some embodiments, the thickness of the buffer layer 6 is D, where 0mm<D≤10mm. In some embodiments, the thickness D of the buffer layer 6 is 1mm, 6mm or 10mm, which is not specifically limited here. The buffer layer 6 has a small thickness, which 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 6 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 6 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 6 is 6mm, it can reduce the overall space of the battery pack while absorbing more vibration impact energy.

[0086] In some embodiments, a fireproof layer (not shown in the figure) is provided on the inner wall of the shell 1 facing the first end surface, and the fireproof layer can prevent thermal runaway from damaging the shell 1 of the battery pack when thermal runaway occurs in the battery cell 2 .

[0087] 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.

[0088] In some embodiments, continue to refer to Figure 4, the distance between the opposite side walls of the two cooling members 4 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 8 is small, which can ensure that the high-temperature substances in the exhaust channel 8 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 8 and causing the exhaust channel 8 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 8 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 3 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).

[0089] In some embodiments, the inner wall of the housing 1 facing the explosion-proof valve 3 is the first inner wall, and the distance between the first inner wall and the explosion-proof valve 3 is 6mm to 20mm. In some embodiments, the distance between the first inner wall and the explosion-proof valve 3 is 6mm, 13mm or 20mm. When the distance between the first inner wall and the explosion-proof valve 3 is 6mm, the overall space requirement of the battery pack is low while ensuring the formation of the exhaust channel 8. When the distance between the first inner wall and the explosion-proof valve 3 is 13mm, the thickness requirements of the cooling member 4 and the buffer layer 6 are reduced, thereby ensuring that the flow rate of the cooling medium per unit time of the cooling member 4 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 3 is 20mm, the height of the exhaust channel 8 can be guaranteed to be higher, the volume of the exhaust channel 8 can be increased, and the exhaust capacity of the exhaust channel 8 can be guaranteed.

[0090] Therefore, two cooling members 4 are provided to cool down the battery cell 2 in thermal runaway, which can not only improve the efficiency of spray cooling for the battery cell 2 in thermal runaway, but also increase the cooling area for the battery cell 2 in normal operation, further improving the cooling effect. The interval between the cooling member 4 that melts through first and the cooling member 4 that melts through later is large, and the cooling medium will not be sprayed onto the cooling member 4 that melts through later, thereby ensuring the double spray cooling effect.

[0091] 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 cooling element extends along the arrangement direction of the battery cell group, and the length of the cooling element 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 cooling element, thereby reducing the number of cooling elements arranged, while reducing the cost of cooling element arrangement, ensuring the relative position of the cooling element 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 first end face does not overlap with the explosion-proof valve. It can be understood that the cooling element completely avoids the explosion-proof valve arrangement of each battery cell, that is, the cooling element and the explosion-proof valve of each battery cell are completely deviated from each other, so that the cooling element 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. In addition, it can also ensure that each battery cell can be arranged corresponding to the cooling element to form a through exhaust channel. It can be understood that multiple battery cells share one exhaust channel, thereby making the battery cells and the cooling element more compact when arranged, reducing the overall space requirement of the battery pack.

[0092] In some embodiments, reference Figure 3 , Figure 4 , Figure 6 and Figure 7 The battery cell 2 also has a second end surface, and the pole is arranged on the second end surface, wherein the first end surface and the second end surface are arranged opposite to each other. In some other embodiments, the first end surface and the second end surface can be arranged adjacent to each other.

[0093] In some embodiments, reference Figure 3 and Figure 4 , the first end face and the second end face are arranged along the height direction of the battery cell 2. The battery cell 2 also has a bar piece 7, wherein the bar piece 7 and the pole are located on the second end face of the battery cell 2, and each bar piece 7 is connected to the poles of two adjacent battery cells 2 to form a bar piece row. Specifically, the bar piece 7 is welded, screwed, riveted or bonded to the pole of the battery cell 2 with a conductive adhesive. For example, the bar piece 7 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 bar piece 7 can be a copper alloy bar piece or an aluminum alloy bar piece, and an observation hole is provided on the bar piece 7. Furthermore, the bar piece 7 can be formed by stamping, machining or casting.

[0094] The first end face is arranged opposite to the second end face. When the explosion-proof valve 3 is opened by a high-temperature substance, the high-temperature substance dissipated from the explosion-proof valve 3 will not affect the pole 5, thereby avoiding a short circuit in the battery pack. Other battery cells 2 in the battery pack that are not thermally runaway can still work normally.

[0095] In other embodiments, the first end surface and the second end surface may also be arranged adjacent to each other, that is, the first end surface and the second end surface are arranged perpendicularly.

[0096] In some embodiments, Figure 1 and Figure 2 As shown, the first direction can be the width direction of the battery cell 2, the two cooling members 4 are arranged at intervals along the width direction of the battery cell 2, and the explosion-proof valve 3 is located between the two cooling members 4. The two cooling members 4 are arranged at intervals along the width direction of the battery cell 2. In this way, the length of the cooling member 4 can be reduced. On the premise that the battery cell 2 can be sprayed after thermal runaway, the use cost of the cooling member 4 is reduced, thereby reducing the manufacturing cost of the battery cell 2.

[0097] In the description of the present invention, reference is made to Figure 2 As shown, with the battery cell 2 stationary on the ground, the front and back are the stacking 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 also the direction perpendicular to the second end face, and the pole and the explosion-proof valve 3 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 cooling members 4 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.

[0098] Of course, in some other embodiments, the first direction may be the length direction of the battery cell 2, the two cooling members 4 are arranged at intervals along the length direction of the battery cell 2, and the explosion-proof valve 3 is located between the two cooling members 4. The two cooling members 4 are arranged at intervals along the length direction of the battery cell, which can increase the contact area between the battery cell 2 and the cooling member 4, thereby improving the cooling effect on the non-thermal runaway battery cell 2. In addition, this setting can also meet the scenario where the explosion-proof valve 3 is longer, and more high-temperature materials can be released to increase the area of ​​the cooling member 4 that is melted through. The increase in the melt-through area can increase the total amount of the cooling medium spraying, thereby improving the cooling effect and response capability of the thermal runaway battery cell 2.

[0099] It should be noted that the projected length of the cooling member 4 on the plane where the first 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 cooling member 4 cools the multiple battery cells 2, but also ensure that the cooling member 4 is effectively connected to the current collector 9 of the battery pack, and the current collector 9 is connected to the liquid cooling circuit to distribute cooling medium to the cooling member 4.

[0100] In some embodiments, each cooling member 4 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 has thermal runaway, the cooling member 4 can be melted through to release the cooling medium to spray and cool the battery cell 2 with thermal runaway. In some examples, the cooling member 4 can also be provided with a weak area in the non-spray range of multiple battery cells 2, so that no matter how the cooling member 4 is installed, it can be ensured that the weak area is within the spray range, reducing the installation requirements for the cooling member 4. When installing the cooling member 4, it is not necessary to install it in a specified installation order, so as to avoid the cooling member 4 being installed in the wrong position and failing to spray and cool the battery cell 2 with thermal runaway.

[0101] In some embodiments, the cooling member 4 is a liquid cooling member made of composite materials, so that the overall performance of the cooling member 4 tends to be consistent, and the cooling member 4 may not be provided with a weak area, and the high-temperature material sprayed out by the explosion-proof valve 3 corresponding to different battery cells 2 can more accurately and timely melt through the part of the cooling member 4 located within the spraying range. The cooling member 4 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.

[0102] 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 cooling element 4 to the thermal runaway battery cell 2 .

[0103] In some embodiments, the cooling member 4 is simultaneously attached to multiple battery cells 2 of the same battery cell group, so that the cooling member 4 can simultaneously cool the surfaces of multiple battery cells 2 of the same battery cell group and is easy to install and arrange.

[0104] In some embodiments, the housing 1 is provided with an exhaust port, which is connected to the exhaust channel 8. The provision of the exhaust port can ensure that the high-temperature material can be discharged as quickly as possible, and prevent the high-temperature material from accumulating in the exhaust channel and damaging the battery cell 2 that is not in thermal runaway. The number of the exhaust ports is the same as the number of the exhaust channels 8, so that the high-temperature material can be discharged in time to avoid affecting other battery cells 2.

[0105] like Figure 8 and Fig. 9 As shown, the outer shell 1 is a rectangular parallelepiped structure, which can accommodate larger battery cells 2 or more battery cells 2. In addition, the outer shell 1 is a rectangular parallelepiped structure, which can facilitate the arrangement of the battery pack and further save the space volume occupied by the entire battery pack.

[0106] The housing 1 includes a first shell 11 and a second shell 12, at least one of the first shell 11 and the second shell 12 has a housing cavity for accommodating the battery cell 2, and the first shell 11 and the second shell 12 are detachably connected. The detachable connection of the first shell 11 and the second shell 12 is convenient for installation and later maintenance. In other embodiments, the first shell 11 and the second shell 12 can also be fixedly connected by welding, and the second shell 12 is located below the first shell 11. The inner wall of the second shell 12, the side walls opposite to the two buffer layers 6, and the side walls opposite to the two cooling members 4 together enclose an exhaust channel 8 corresponding to the explosion-proof valve 3, so that high-temperature substances can be gathered in the exhaust channel 8 and then discharged through an exhaust port connected to the exhaust channel 8. Optionally, the exhaust port is arranged on the side wall of the first shell 11 or the second shell 12, and the side wall provided with the exhaust port is arranged perpendicular to the extension direction of the exhaust channel. In order to reduce the flow path of the high-temperature substance, the exhaust port is specifically arranged at the second shell 12.

[0107] In some embodiments, the cooling element 4 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.

[0108] 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 battery pack provided in the above embodiments, the battery pack is arranged on the vehicle body, and the vehicle body provides support for the battery pack.

[0109] 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.

[0110] In some embodiments, the battery pack disclosed in the present invention can be used not only in vehicles, but also in ships or other mechanical devices.

[0111] 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 pack, characterized in that: include: A housing (1), wherein the housing (1) has a receiving cavity; A battery core (2), the battery core (2) being located in the accommodating cavity, and a first end surface of the battery core (2) being provided with an explosion-proof valve (3); A liquid cooling structure, the liquid cooling structure comprising two cooling elements (4), the two cooling elements (4) being respectively arranged in contact with the first end surface and spaced apart on both sides of the explosion-proof valve (3); The inner wall of the accommodating cavity opposite to the explosion-proof valve (3) and the side walls opposite to the two cooling components (4) together enclose an exhaust passage (8) corresponding to the explosion-proof valve (3).

2. The battery pack according to claim 1, characterized in that: The projection of the cooling member (4) on the first end face does not overlap with the explosion-proof valve (3), at least a portion of the cooling member (4) is located within the spray range of the explosion-proof valve (3), and the portion of the cooling member (4) located within the spray range of the explosion-proof valve (3) can be melted through by the high-temperature material sprayed from the battery cell (2) in thermal runaway.

3. The battery pack according to claim 1, characterized in that: The portion of the cooling element (4) located within the spraying range of the explosion-proof valve (3) is provided with a weak area; and / or, The cooling element (4) is a liquid cooling element made of a composite material.

4. The battery pack according to claim 1, characterized in that: A buffer layer (6) is filled between the cooling element (4) and the inner wall of the outer shell (1); the inner wall of the accommodating cavity opposite to the explosion-proof valve (3), the side walls opposite to the two buffer layers (6), and the side walls opposite to the two cooling elements (4) together enclose the exhaust passage (8).

5. The battery pack according to claim 4, characterized in that: The width of the buffer layer (6) is w1, and the width of the cooling element (4) is w2, wherein 0.1≤w1 / w2≤10; and / or, The thickness of the buffer layer (6) is D, wherein 0 mm < D ≤ 10 mm.

6. The battery pack according to claim 1, characterized in that: The inner wall of the outer shell (1) facing the first end surface is provided with a fireproof layer.

7. The battery pack according to any one of claims 1 to 6, characterized in that: The distance between the two opposite side walls of the cooling members (4) is w3, and the length of the battery core (2) is w4, wherein 0.1≤w3 / w4≤0.8; And / or, the inner wall of the housing (1) facing the explosion-proof valve (3) is a first inner wall, and the distance between the first inner wall and the explosion-proof valve (3) is 6 mm to 20 mm.

8. The battery pack 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 cooling member (4) extends along the arrangement direction of the battery cell group, and the length of the cooling member (4) is greater than or equal to the total length of the multiple battery cells (2) arranged in the first direction.

9. The battery pack according to any one of claims 1 to 6, characterized in that: The housing (1) is provided with an exhaust port, and the exhaust port is communicated with the exhaust channel (8).

10. A vehicle, comprising a vehicle body, characterized in that: Comprising a battery pack as described in any one of claims 1 to 9, wherein the battery pack is arranged on the vehicle body.

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