Battery box cover and battery pack

Abstract

The invention relates to a battery box cover and a battery pack, and the battery box cover comprises a main body which is internally provided with a liquid cooling flow channel, a fire-fighting flow channel and a communication flow channel; the communicating flow channel comprises a first communicating flow channel and a second communicating flow channel; at least one fire-fighting flow channel is communicated with the liquid cooling flow channel through a first communication flow channel, and is communicated with the same liquid cooling flow channel through a second communication flow channel; the first communication flow channel and the second communication flow channel which are communicated with the same fire-fighting flow channel are correspondingly arranged and form a first communication port and a second communication port with the liquid cooling flow channel respectively, and the first communication port is located at the upstream of the corresponding second communication port; the area, used for forming the fire-fighting flow channel, of the main body forms a fire-fighting part, and the fire-fighting part can be broken when the battery cell is in thermal runaway, so that cooling liquid in the fire-fighting flow channel is sprayed out. And the thermal runaway battery cells are cooled in time, so that the risk of heat spreading of the battery pack is greatly reduced, and the safety performance of the battery pack is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of batteries, and in particular to a battery box cover and a battery pack. Background Art

[0002] With the rapid expansion and development of the new energy market, the market share of new energy vehicles has gradually increased. Therefore, power batteries, as the core components of new energy vehicles, are increasingly used in people's lives.

[0003] Power batteries usually include multiple cells connected in series, parallel or mixed, and the cells are installed in a battery box. When a cell experiences thermal runaway, the explosion-proof valve of the cell discharges the gas inside the cell into the storage space, and the thermal runaway cell is not cooled down at this time. Due to the high temperature of the thermal runaway gas, the risk of heat spread in the battery is greater, which is not conducive to improving the safety performance of the battery. Summary of the invention

[0004] Based on this, it is necessary to provide a battery box cover and a battery pack that can improve the safety performance of the battery pack in order to address the problem of low safety performance of traditional battery packs.

[0005] In one aspect, the present application provides a battery box cover, comprising:

[0006] A main body, wherein a liquid cooling flow channel, a fire fighting flow channel and a connecting flow channel are arranged in the main body; the connecting flow channel comprises a first connecting flow channel and a second connecting flow channel; at least one of the fire fighting flow channels is connected to the liquid cooling flow channel through the first connecting flow channel, and is connected to the same liquid cooling flow channel through the second connecting flow channel; the first connecting flow channel and the second connecting flow channel connected to the same fire fighting flow channel are arranged correspondingly and form a first connecting port and a second connecting port with the liquid cooling flow channel respectively, and the first connecting port is located upstream of the second connecting port corresponding thereto;

[0007] The area of ​​the main body used to form the fire-fighting flow channel forms a fire-fighting portion, and the fire-fighting portion can be broken when the battery cell thermally runs away, so that the coolant in the fire-fighting flow channel is sprayed out.

[0008] In one of the embodiments, the ratio of the cross-sectional area of ​​the liquid-cooling channel to the cross-sectional area of ​​the connecting channel is greater than or equal to 2.5.

[0009] In one embodiment, the liquid cooling channel includes a plurality of sub-channels that are interconnected, the flow directions of two adjacent sub-channels belonging to the same liquid cooling channel are opposite, and one sub-channel is located upstream of another sub-channel; at least one fire protection channel is arranged between two adjacent sub-channels; the first connecting channel and the upstream sub-channel form the first connecting port, and the second connecting channel and the downstream sub-channel form the second connecting port;

[0010] The first communication port is disposed at the end of the upstream sub-flow channel, and the second communication port is disposed at the end of the downstream sub-flow channel, so that the flow direction of the fire fighting flow channel is the same as that of the downstream sub-flow channel.

[0011] In one embodiment, the battery box cover further includes a first regulating mechanism, which is disposed in the first communicating flow channel; when the fire-fighting part is in a ruptured state, the first regulating mechanism is used to accelerate the coolant to flow into the fire-fighting flow channel;

[0012] and / or

[0013] The battery box cover also includes a second adjusting mechanism, which is arranged in the second connecting flow channel; when the fire-fighting part is in an unruptured state, the second adjusting mechanism is used to reduce the flow rate of the coolant in the fire-fighting flow channel, and when the fire-fighting part is in a ruptured state, the second adjusting mechanism is used to accelerate the flow of the coolant into the fire-fighting flow channel.

[0014] In one embodiment, the first regulating mechanism is a Tesla valve disposed in the first communicating flow channel, and the coolant flows through the Tesla valve in a positive direction;

[0015] and / or

[0016] The second regulating mechanism is a Tesla valve arranged in the second connecting flow channel; when the fire-fighting part is in the unruptured state, the coolant flows through the Tesla valve in the reverse direction, and when the fire-fighting part is in the ruptured state, the coolant flows through the Tesla valve in the forward direction.

[0017] In one embodiment, the main body includes a lower plate and an upper plate, the upper plate covers the lower plate and the liquid cooling channel, the connecting channel and the fire fighting channel are formed therebetween;

[0018] The lower plate is stamped toward the upper plate to form the stamped weak portion, and the stamped weak portion forms the fire protection portion. The height h1 of the stamped weak portion and the depth h3 of the fire protection flow channel satisfy the relationship: 0.3≤h1 / h3≤0.8.

[0019] In one embodiment, the main body includes a lower plate and an upper plate, the upper plate covers the lower plate and the liquid cooling channel, the connecting channel and the fire fighting channel are formed therebetween;

[0020] The lower plate includes a first groove portion and a first straight portion, and the upper plate includes a second groove portion and a second straight portion, and the first groove portion and the second groove portion have opposite concave directions;

[0021] The first groove portion and the second straight portion form the liquid cooling channel, the first straight portion and the second groove portion form the fire fighting channel, and the fire fighting portion is disposed on the first straight portion.

[0022] In one embodiment, the liquid cooling channel includes a plurality of sub-channels that are interconnected, the flow directions of two adjacent sub-channels belonging to the same liquid cooling channel are opposite, and one sub-channel is located upstream of another sub-channel; at least one fire protection channel is arranged between two adjacent sub-channels; the first connecting channel and the upstream sub-channel form the first connecting port, and the second connecting channel and the downstream sub-channel form the second connecting port;

[0023] The fire-fighting flow channel is used to correspond to the explosion-proof valve of the battery cell. The sub-flow channels are respectively arranged on both sides of the fire-fighting flow channel. At least two adjacent sub-flow channels on one side belonging to the same liquid-cooling flow channel correspond to one pole of the battery cell, and at least two adjacent sub-flow channels on the other side belonging to the same liquid-cooling flow channel correspond to another pole of the battery cell.

[0024] In one of the embodiments, a heat insulating member is provided on a side of the first straight portion away from the upper plate, the heat insulating member is provided in an area where the first straight portion and the second straight portion overlap, and the heat insulating member is used to isolate the explosion-proof valve and the pole of the battery cell.

[0025] On the other hand, the present application also provides a battery pack, comprising a box body, a battery cell and the above-mentioned battery box cover; the battery cell is installed in the box body, and the battery box cover is arranged on the box body;

[0026] The liquid cooling channel is opposite to the pole of the battery cell, and the fire protection channel is opposite to the explosion-proof valve of the battery cell.

[0027] Compared with the prior art, this application has the following beneficial effects:

[0028] The main body has a liquid cooling channel, which can cool the battery cell; at the same time, the main body has a fire-fighting channel. When the battery cell has thermal runaway and the explosion-proof valve of the battery cell discharges the high-temperature gas inside the battery cell, the fire-fighting part can rupture under the action of the high-temperature gas. When the fire-fighting part ruptures, the coolant can flow out of the fire-fighting channel and spray toward the battery cell, thereby continuously cooling the thermal runaway battery cell. In this way, by timely cooling the thermal runaway battery cell, the risk of heat spread in the battery pack is greatly reduced, which is conducive to improving the safety performance of the battery pack. In addition, when the battery cell does not have thermal runaway, the coolant can circulate in the fire-fighting channel. It is precisely because the coolant is always circulating in the fire-fighting channel that when the battery cell has thermal runaway, the coolant can flow out of the fire-fighting channel in time compared to the closed fire-fighting channel (the closed fire-fighting channel is a channel in which the coolant cannot circulate), thereby timely cooling the thermal runaway battery cell. At the same time, when the fire protection part ruptures, the fire protection part acts as the fluid outlet of the fire protection flow channel, so that the second connecting flow channel originally serving as the liquid outlet channel becomes the liquid inlet flow channel under the action of the pressure difference, and the first connecting flow channel and the second connecting flow channel both serve as the liquid inlet flow channel of the fire protection flow channel, which can ensure that sufficient coolant flows to the thermal runaway battery cell and ensure the cooling effect on the thermal runaway battery cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 A structural diagram of a battery pack provided in one embodiment of the present application;

[0030] Figure 2 for Figure 1 An exploded view of the battery pack shown in;

[0031] Figure 3 for Figure 1 A structural diagram of a partial structure of a battery pack shown in ;

[0032] Figure 4 for Figure 1 The structural diagram of the battery box cover shown in;

[0033] Figure 5 for Figure 4 The structural diagram of the lower plate of the battery box cover shown in ;

[0034] Figure 6 A distribution diagram of the flow channel in the battery box cover provided in one embodiment of the present application ( Figure 6 The green arrows in the middle represent the flow direction of the coolant in the liquid cooling channel, and the cyan arrows represent the flow direction of the coolant in the fire protection channel when the fire protection part is not broken);

[0035] Figure 7 It is the flow diagram of the coolant in the liquid cooling channel and the fire protection channel when the battery cell has thermal runaway;

[0036] Figure 8 for Figure 1A cross-sectional view of a battery pack shown in ;

[0037] Fig. 9 for Figure 8 An enlarged view of the battery pack at point F shown in FIG.

[0038] Fig.10 for Figure 4 An enlarged view of the battery box cover at point A shown in FIG.

[0039] Fig.11 A distribution diagram of battery cells of a battery pack provided in another embodiment of the present application;

[0040] Fig.12 For the corresponding Fig.11 Flow path arrangement diagram of the cell layout shown in ;

[0041] Fig.13 It is a schematic diagram of the structure when the fluid flows through the Tesla valve in the forward direction;

[0042] Fig.14 Schematic diagram of the structure when the fluid flows through the Tesla valve in the reverse direction.

[0043] Description of reference numerals:

[0044] 1000, battery pack; 100, battery box cover; 10, main body; 11, liquid cooling channel; 111, sub-channel; 12, fire protection channel; 13, connecting channel; 131, first connecting channel; 132, second connecting channel; 14, fire protection part; 15, lower plate; 151, first groove part; 152, first straight part; 16, upper plate; 161, second groove part; 162, second straight part; 17, liquid inlet; 18, liquid outlet; 20, Tesla valve; 200, box; 300, battery cell; 301, pole; 302, explosion-proof valve; 400, thermal conductive gasket; 500, thermal insulation; 600, convergence assembly; 601, bar piece; A1, first module; A2, second module; B, first connecting port; D, second connecting port. DETAILED DESCRIPTION

[0045] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present invention, so the present invention is not limited by the specific embodiments disclosed below.

[0046] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0047] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0048] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like 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, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0049] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0050] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used herein are for illustrative purposes only and are not intended to be the only implementation method.

[0051] See also Figure 1-Figure 3 An embodiment of the present application provides a battery pack 1000, including a box body 200, a battery cell 300 and a battery box cover 100. The battery cell 300 is installed in the box body 200, and the battery box cover 100 is covered on the box body 200 to close the opening of the box body 200, thereby protecting the battery cell 300 located in the box body 200.

[0052] Optionally, the box body 200 is a hollow rectangular parallelepiped structure with one end open. To match the shape of the box body 200, the battery box cover 100 is a rectangular parallelepiped plate structure. After the battery box cover 100 with a rectangular parallelepiped plate structure is placed on the box body 200, the battery box cover 100 and the box body 200 together form a hollow rectangular parallelepiped structure. At this time, the outer contour of the entire battery pack 1000 is a rectangular parallelepiped. It is conceivable that in some other embodiments, the shapes of the box body 200 and the battery box cover 100 are not limited. For example, the box body 200 can also be set as a hollow cylindrical structure with one end open. To match the shape of the box body 200, the battery box cover 100 is set to be circular.

[0053] See also Figure 4-Figure 6 The battery box cover 100 includes a main body 10, and at least one liquid cooling channel 11 is provided in the main body 10. The coolant in the external liquid cooling system flows from the liquid inlet 17 to the liquid cooling channel 11, and flows back to the liquid cooling system from the liquid outlet 18, and the cycle repeats to cool the battery cell 300 installed in the box body 200. Generally, the power for the circulation of the coolant is provided by a pump. Figure 6 When a plurality of liquid cooling channels 11 are provided in the main body 10, the plurality of liquid cooling channels 11 may share the liquid inlet 17 and the liquid outlet 18. Of course, in other implementations, when a plurality of liquid cooling channels 11 are provided in the main body 10, the liquid inlets 17 and the liquid outlets 18 of the plurality of liquid cooling channels 11 may also be independently provided, which is not limited here.

[0054] Optionally, the pole 301 is disposed on the side of the battery cell 300 facing the battery box cover 100, and the position of the liquid cooling channel 11 is opposite to the pole 301, and the coolant flowing through the liquid cooling channel 11 can cool the pole 301 of the battery cell 300. Of course, in some other embodiments, the liquid cooling channel 11 can also be opposite to other positions of the battery cell 300, as long as the effect of cooling the battery cell 300 can be achieved, which is not limited here.

[0055] In some embodiments, the battery pack 1000 has multiple rows of battery cells arranged in sequence along a first direction, and each row of battery cells includes multiple battery cells 300 arranged along a second direction. In other embodiments, the battery pack 1000 may also include only one row of battery cells, and the row of battery cells includes multiple battery cells 300 arranged along the second direction. The first direction intersects with the second direction. Specifically, the first direction and the second direction are perpendicular. When the battery pack 1000 is a rectangular parallelepiped structure, one of the first direction and the second direction is the length direction of the battery pack 1000, and the other is the width direction of the battery pack 1000, and the battery box cover 100 is covered on the top of the box body 200 in the height direction. As Figure 2 As shown, the first direction is Figure 2 The middle Y direction, the second direction is Figure 2 In the X direction, one liquid cooling channel 11 corresponds to one battery cell row, so that each battery cell 300 can be cooled to improve the heat exchange efficiency.

[0056] Generally, each battery cell 300 has two poles 301, and each row of battery cells includes two rows of poles 301 arranged along the first direction, and each row of poles 301 includes a plurality of poles 301 arranged in sequence along the second direction. Figure 5 In order to make the liquid cooling channel 11 and the pole 301 opposite to each other, each liquid cooling channel 11 is configured to include a plurality of interconnected sub-channels 111, and the flow directions of each two adjacent sub-channels 111 belonging to the same liquid cooling channel 11 are opposite, and one sub-channel 111 is located upstream of another sub-channel 111. Specifically, each sub-channel 111 extends along the second direction, and each sub-channel 111 is arranged at intervals along the first direction. Figure 6 At this time, there are two rows of battery cells, each row of battery cells corresponds to a liquid cooling channel 11, and each liquid cooling channel 11 includes two sub-channels 111 with opposite flow directions. The liquid cooling channel 11 can be arranged reasonably to improve the cooling effect of the battery cell 300.

[0057] In some specific embodiments, the battery pack 1000 has two rows of battery cells, and in this case, there are four rows of poles. Each row of poles may be opposite to at least two adjacent sub-channels 111 of the same liquid cooling channel 11. In this case, each row of poles corresponds to at least two sub-channels 111 with opposite flow directions. Figure 5As shown. Specifically, each row of poles is opposite to two adjacent sub-channels 111, and at this time, each row of poles corresponds to two sub-channels 111 with opposite flow directions. The coolant exchanges heat with the battery cells 300 on the flow path. As the temperature of the coolant increases during the heat exchange, if each row of battery cells corresponds to only one sub-channel 111, the temperature of the battery cells 300 at both ends will be uneven. By providing at least two sub-channels 111 with opposite flow directions corresponding to each row of poles, the temperature uniformity of the battery cells 300 at both ends can be improved. It is conceivable that in some other specific embodiments, there is no limitation on how the battery cells 300 are arranged in the battery pack 1000, and there is no limitation on how the liquid cooling channel 11 is arranged. The arrangement of the liquid cooling channel 11 is sufficient as long as it can achieve the purpose of cooling the battery cells 300.

[0058] The battery pack 1000 further includes a busbar assembly 600, which includes a bar 601, which is electrically connected to the poles 301 of the battery cells 300 to achieve series connection, parallel connection or mixed connection between the battery cells 300. The bar 601 is located between the battery box cover 100 and the battery cells 300, and the liquid cooling channel 11 is based on being able to cover the bar 601. The battery box cover 100 can conduct heat to the poles 301 of the battery cells 300 through the bar 601. When the poles 301 of the battery cells 300 are arranged in a row, the bar 601 is also arranged in a row.

[0059] Continue reading Figure 2 The battery pack 1000 also includes a thermally conductive gasket 400, which extends along the second direction and is disposed between the bar piece 601 and the battery case cover 100 to transfer heat between the bar piece 601 and the battery case cover 100. The thermally conductive gasket 400 can not only conduct heat, but also fill the gap between the battery case cover 100 and the bar piece 601, so that the two are in contact for heat exchange. In addition, the thermally conductive gasket 400 can also play a buffering role to avoid hard contact between the battery case cover 100 and the bar piece 601. The thermal conductivity coefficient of the thermally conductive gasket 400 λ ≥ 0.5W / (m·K), ensuring that the thermally conductive gasket 400 has a certain thermal conductivity, and the thickness is 1≤a≤5mm. If the thickness of the thermally conductive gasket 400 is too thin, the buffering effect is too weak, and if the thickness is too thick, the heat exchange between the battery case cover 100 and the bar piece 601 is affected.

[0060] Further reading Figure 5 and Figure 6, a fire-fighting flow channel 12 and a connecting flow channel 13 are also provided in the main body 10, and at least one fire-fighting flow channel 12 is provided with a corresponding connecting flow channel 13. Each connecting flow channel 13 includes a first connecting flow channel 131 and a second connecting flow channel 132, and at least one fire-fighting flow channel 12 is connected to the liquid-cooling flow channel 11 through the first connecting flow channel 131, and is connected to the same liquid-cooling flow channel 11 through the second connecting flow channel 132. That is, at least one fire-fighting flow channel 12 is connected to the same liquid-cooling flow channel 11 through the corresponding first connecting flow channel 131 and the second connecting flow channel 132.

[0061] Specifically, the connecting flow channel 13 and the fire flow channel 12 are arranged in a one-to-one correspondence. That is, the number of connecting flow channels 13 is the same as the number of fire flow channels 12 arranged in the main body 10, so as to ensure that each fire flow channel 12 is provided with a corresponding connecting flow channel 13, that is, each fire flow channel 12 is provided with a corresponding first connecting flow channel 131 and a second connecting flow channel 132. The fire flow channel 12 is connected to the liquid cooling flow channel 11 through the corresponding first connecting flow channel 131, and the fire flow channel 12 is also connected to the same liquid cooling flow channel 11 through the corresponding second connecting flow channel 132. Continue reading Figure 6 The first communication channel 131 and the liquid cooling channel 11 form a first communication port B, and the second communication channel 132 and the liquid cooling channel 11 form a second communication port D. The first communication port B corresponds to the second communication port D. The first communication port B is located upstream of the second communication port D corresponding thereto.

[0062] It should be noted that the first connecting port B is located upstream of the second connecting port D, which means that on the flow path of the coolant, the coolant first flows through the first connecting port B and then flows through the second connecting port D. In the above arrangement, the fire-fighting channel 12 is connected to the liquid-cooling channel 11 through the first connecting channel 131 and the second connecting channel 132, and the first connecting port B between the first connecting channel 131 and the liquid-cooling channel 11 is located upstream of the second connecting port D between the second connecting channel 132 and the liquid-cooling channel 11. Then, after the coolant flows to the liquid-cooling channel 11 through the liquid inlet 17, it can enter the fire-fighting channel 12 through the first connecting port B (at this time, the first connecting channel 131 serves as the liquid inlet channel of the fire-fighting channel 12), and finally flows to the liquid-cooling channel 11 again from the second connecting port D (at this time, the second connecting channel 132 serves as the liquid outlet channel of the fire-fighting channel 12), so as to realize the circulation of the coolant in the fire-fighting channel 12.

[0063] For further information, see Figure 5The area of ​​the main body 10 used to form the fire-fighting flow channel 12 forms a fire-fighting section 14, and the fire-fighting section 14 can rupture when the battery cell 300 is under thermal runaway, so that the coolant in the fire-fighting flow channel 12 is ejected. Optionally, the fire-fighting flow channel 12 is opposite to the explosion-proof valve 302 of the battery cell 300, so that the high-temperature gas ejected from the explosion-proof valve 302 can be directly ejected to the fire-fighting section 14, so that the fire-fighting section 14 ruptures (due to the high temperature and high pressure of the high-temperature gas, the fire-fighting section 14 can be melted through under the high temperature of the high-temperature gas and / or broken through under the high pressure of the high-temperature gas), so as to avoid the fire-fighting section 14 being too far away from the explosion-proof valve 302 of the battery cell 300, so as to achieve a better fire-fighting effect.

[0064] The battery box cover 100 provided by the present application has a liquid cooling channel 11 in the main body 10, which can play a role in cooling the battery cell 300; at the same time, the main body 10 has a firefighting channel 12. When the battery cell 300 has thermal runaway and the explosion-proof valve 302 of the battery cell 300 discharges the high-temperature gas inside the battery cell 300, the firefighting part 14 can rupture under the action of the high-temperature gas. When the firefighting part 14 ruptures, the coolant can flow out of the firefighting channel 12 and spray toward the battery cell 300, thereby continuously cooling the thermal runaway battery cell 300. In this way, by timely cooling the thermal runaway battery cell 300, the risk of heat spread of the battery pack 1000 is greatly reduced, which is conducive to improving the safety performance of the battery pack 1000.

[0065] It should be noted that when the battery cell 300 does not experience thermal runaway, the coolant can circulate in the fire flow channel 12. It is because the coolant is always circulating in the fire flow channel 12 that when the battery cell 300 experiences thermal runaway, compared with the closed fire flow channel 12 (the closed fire flow channel 12 is a flow channel in which the coolant cannot circulate), the coolant can flow out of the fire flow channel 12 in time, thereby timely cooling down the thermal runaway battery cell 300 and continuously cooling down the temperature. At the same time, refer to Figure 7 When the fire-fighting part 14 ruptures, the fire-fighting part 14 serves as the fluid outlet of the fire-fighting flow channel 12, so that the second connecting flow channel 132 originally serving as the liquid outlet channel becomes the liquid inlet flow channel under the action of the pressure difference, and the first connecting flow channel 131 and the second connecting flow channel 132 both serve as the liquid inlet flow channels of the fire-fighting flow channel 12, which can ensure that more coolant flows to the thermal runaway battery cell 300, thereby ensuring the cooling effect on the thermal runaway battery cell 300.

[0066] In some embodiments, see Figure 3, the explosion-proof valves 302 of the battery cells 300 included in the battery cell row are arranged in rows, that is, each battery cell 300 is provided with an explosion-proof valve 302, and the explosion-proof valves 302 of the battery cells 300 of the battery cell row are arranged in sequence along the second direction. In order to make the fire-fighting flow channel 12 opposite to the explosion-proof valve 302, the fire-fighting flow channel 12 is arranged to extend along the second direction. Optionally, the first connecting flow channel 131 and the second connecting flow channel 132 both extend along the first direction. Each row of explosion-proof valves 302 is provided with poles 301 on both sides of the first direction, and at this time, sub-flow channels 111 are provided on both sides of the fire-fighting flow channel 12, and the sub-flow channels 111 are opposite to the poles 301 on both sides to cool the poles 301 on both sides. It can be understood that in other embodiments, the explosion-proof valve 302 of the battery cell 300 can also be arranged in other ways, and at the same time, the fire-fighting flow channel 12 is different according to the different positions of the explosion-proof valve 302.

[0067] In some specific embodiments, at least one fire-fighting flow channel 12 is disposed between two adjacent sub-flow channels 111, and the two adjacent sub-flow channels 111 are respectively an upstream sub-flow channel 111 and a downstream sub-flow channel 111. The first connecting flow channel 131 forms a first connecting port B with the upstream sub-flow channel 111, and the second connecting flow channel 132 forms a second connecting port D with the downstream sub-flow channel 111. The first connecting port B is disposed at the end of the upstream sub-flow channel 111, and the second connecting port D is disposed at the end of the downstream sub-flow channel 111, so that the flow direction of the fire-fighting flow channel 12 is the same as that of the downstream sub-flow channel 111. In this way, when the fire-fighting part 14 is not broken, the diversion of the fire-fighting flow channel 12 is at the end of the upstream sub-flow channel 111, so as to avoid the fire-fighting flow channel 12 diverting too much coolant, affecting the heat exchange effect of the liquid-cooling flow channel 11, and reducing the heat exchange effect of the fire-fighting flow channel 12 as much as possible. In another specific embodiment, the first connecting port B is arranged at the starting end of the upstream sub-channel 111, and the second connecting port D is arranged at the starting end of the downstream sub-channel 111, so that the flow direction of the fire-fighting channel 12 is the same as that of the upstream sub-channel 111. When the fire-fighting part 14 is broken, the coolant flows from the starting ends of the upstream and downstream sub-channels 111 to the fire-fighting part 14, which can increase the fire-fighting flow rate and ensure the fire-fighting effect.

[0068] Continue reading Figure 2 , Figure 8 and Fig. 9The battery pack 1000 also includes a heat insulating member 500 extending along the second direction. The heat insulating member 500 is disposed between the battery cell 300 and the battery box cover 100, and the heat insulating member 500 is disposed on both sides of the explosion-proof valve 302 in the first direction. The heat insulating member 500 can prevent the high-temperature gas ejected from the battery cell 300 due to thermal runaway from being ejected toward the area corresponding to the liquid cooling channel 11 and causing the area corresponding to the liquid cooling channel 11 to rupture. At the same time, it can also isolate the bar 601 and the explosion-proof valve 302 or isolate the pole 301 and the explosion-proof valve 302 to prevent the ejected metal chips from falling next to the bar 601 or the pole 301 and causing a short circuit. The thermal conductivity of the heat insulating member 500 is λ≤0.05W / (m·K). The excellent thermal insulation performance of the heat insulating member 500 is beneficial to both the liquid cooling channel 11 and the bar 601.

[0069] Continue reading Figure 4 The main body 10 includes a lower plate 15 and an upper plate 16, which are covered with a liquid cooling channel 11, a communication channel 13 and a fire fighting channel 12, and the lower plate 15 is located on the side of the battery box cover 100 close to the battery cell 300, and the fire fighting part 14 is formed on the lower plate 15. The upper plate 16 and the lower plate 15 are sealed by gluing or welding to prevent leakage of the coolant.

[0070] Continue reading Figure 4 Also see Fig.10 The lower plate 15 includes a first groove portion 151 and a first straight portion 152, and the upper plate 16 includes a second groove portion 161 and a second straight portion 162. The first groove portion 151 and the second groove portion 161 are recessed in opposite directions. The first groove portion 151 and the second straight portion 162 form a liquid cooling channel 11, that is, the groove wall of the first groove portion 151 and the second straight portion 162 form a liquid cooling channel 11. The first straight portion 152 and the second groove portion 161 form a fire fighting channel 12, that is, the groove wall of the first straight portion 152 and the second groove portion 161 form a fire fighting channel 12. The fire fighting portion 14 is disposed on the first straight portion 152. With this arrangement, the position where the liquid cooling channel 11 is provided on the battery box cover 100 is closer to the battery cell 300, thereby improving the cooling effect on the battery cell 300; at the same time, the position where the fire protection channel 12 is provided on the battery box cover 100 is farther away from the battery cell 300, thereby ensuring that there is a sufficient gap between the explosion-proof valve 302 and the battery box cover 100, so that the lower plate 15 will not block the spray valve of the explosion-proof valve 302, thereby ensuring the pressure relief effect of the battery cell 300, and at the same time, the large gap between the explosion-proof valve 302 and the battery box cover 100 can reserve a sufficient exhaust path for convenient exhaust.

[0071] Generally, the second groove portion 161 of the upper plate 16 is formed by stamping, and the stamping shape can provide the overall strength of the battery box cover 100 .

[0072] In other embodiments, the lower plate 15 and the upper plate 16 may also be arranged in other ways, which are not limited here. For example, the groove portion of the upper plate 16 and the groove wall of the groove portion of the lower plate 15 may be arranged to jointly form the liquid cooling channel 11, the fire protection channel 12 and the connecting channel 13.

[0073] In some specific implementations, please refer to Figure 8 The heat insulating member 500 is disposed on the side of the first straight portion 152 away from the upper plate 16, and the heat insulating member 500 is disposed in the region where the first straight portion 152 and the second straight portion 162 overlap. In this way, the heat insulating member 500 does not occupy the space formed by the upper plate 16 and the lower plate 15 to form the liquid cooling channel 11 and the fire fighting channel 12, thereby ensuring the cooling and fire fighting effects.

[0074] In some embodiments, the flow channel depth h of the liquid-cooling flow channel 11 (when the battery box cover 100 is installed on the top of the box body 200, the flow channel depth of the liquid-cooling flow channel 11 is its dimension in the height direction) satisfies: 2≤h≤8mm, so as to ensure the heat dissipation effect on the pole 301 of the battery cell 300. At the same time, the liquid-cooling flow channel 11 can cover the bar 601 in the first direction to prevent the ejection of the thermal runaway battery cell 300 from falling on the bar 601 and causing the battery cell 300 to short-circuit. The width s of the fire-fighting flow channel 12 depends on the diameter d of the explosion-proof valve 302, and s≥1.5d is generally set. Optionally, the depression depth b of the second groove portion 161 satisfies: 3≤b≤15mm, that is, the depth h3 of the fire-fighting flow channel 12 satisfies 3≤h3≤15mm.

[0075] Further, the lower plate 15 is punched to form a punched weak portion, and the punched weak portion forms the fire protection portion 14. The punched weak portion is easy to break under the action of high-temperature gas to ensure the fire protection effect.

[0076] Since the stamping process will cause the stamping part to stretch, that is, thinning will occur in the stamping R corner area, the thinning rate of the R corner area of ​​the stamping weak part can be controlled at 40%-60%, and the thinning rate of other areas of the stamping weak part is controlled at ≤20%. In this way, when the battery cell 300 thermally runs away, the R corner area will be damaged first, allowing the fluid to flow out to cool the battery cell 300.

[0077] It should be noted that the stamped weak portion may be a protrusion formed on the lower plate 15 or a convex strip formed on the lower plate 15, and the shape of the stamped weak portion is not limited here. At the same time, each fire flow channel 12 may correspond to one stamped weak portion, or may correspond to multiple stamped weak portions, and this is also not limited here. Such a design can further increase the gap between the explosion-proof valve 302 and the battery box cover 100, which is convenient for exhaust.

[0078] In some specific implementations, each explosion-proof valve 302 is provided with a stamping weak portion, and the stamping shape is determined according to the shape of the explosion-proof valve 302. The lower plate 15 is stamped in a direction close to the upper plate 16 to form a stamping weak portion, and the ratio of the stamping area S3 of the stamping weak portion to the area S4 of the explosion-proof valve 302 is 0.8≤S3 / S4≤1.2. If the stamping area is too small, it will affect the high-temperature gas of the explosion-proof valve 302 to break through the stamping weak portion, and if the stamping area is too large, it will occupy more space in the inner cavity of the fire-fighting flow channel 12, affecting the flow of fluid.

[0079] In some other specific implementations, a plurality of explosion-proof valves 302 may be provided with one corresponding stamping weakened portion, or one explosion-proof valve 302 may be provided with a plurality of stamping weakened portions.

[0080] Furthermore, the height h1 of the punched weak part and the depth h3 of the fire channel 12 satisfy the relationship: 0.3≤h1 / h3≤0.8. If the height of the punched weak part is too small, the strength of the weak area is large and it is not easy to break through. If the height is too large, it occupies the volume of the fire channel 12 and affects the flow of fluid.

[0081] In some embodiments, since the explosion-proof valve 302 area of ​​the battery cell 300 does not need heat exchange during normal use of the battery, the flow in the fire-fighting flow channel 12 can be controlled when the battery cell 300 is not in thermal runaway. Specifically, the cross-sectional areas of the first communication flow channel 131 and the second communication flow channel 132 are both smaller than the cross-sectional area of ​​the liquid cooling flow channel 11, so that the flow of the coolant in the fire-fighting flow channel 12 is smaller, so that more coolant is used for heat dissipation of other parts of the battery cell 300.

[0082] Optionally, the ratio of the cross-sectional area S1 of the liquid cooling channel 11 to the cross-sectional area S2 of the connecting channel 13 (including the first connecting channel 131 and the second connecting channel 132) is greater than or equal to 2.5, so that the flow rate of the fluid in the fire fighting channel 12 can be ensured to be small. The position setting of the first connecting channel 131 and the second connecting channel 132 can work together to reduce the influence of the fire fighting channel 12 on the overall liquid cooling efficiency.

[0083] In the above embodiments, the cross-sectional areas of the first connecting flow channel 131 and the second connecting flow channel 132 corresponding to the fire-fighting flow channel 12 are both smaller than the cross-sectional area of ​​the liquid-cooling flow channel 11. It is conceivable that in some other embodiments, the cross-sectional area of ​​one of the first connecting flow channel 131 and the second connecting flow channel 132 corresponding to the fire-fighting flow channel 12 can be set to be smaller than the cross-sectional area of ​​the liquid-cooling flow channel 11, and the cross-sectional area of ​​the other can be equal to or larger than the cross-sectional area of ​​the liquid-cooling flow channel 11.

[0084] In some specific implementations, the width c of the communication channel 13 is: 4mm≤c≤15mm, and the depth h2 of the communication channel 13 is: 1mm≤h2≤3mm. If the width and depth of the communication channel 13 are too small, impurities will easily block the communication channel 13, and if the width and depth of the communication channel 13 are too large, the flow rate in the fire protection channel 12 will be too large, increasing the liquid cooling energy loss.

[0085] See also Fig.11 and Fig.12 At the same time, the connecting flow channel 13 can also control the flow size of each area. For example, when the battery pack 1000 includes two asymmetric modules, the flow channels corresponding to the areas of the two modules need to be set asymmetrically, which can reduce the temperature difference between the two modules. Fig.11 It can be seen that the heat exchange area required by the first module A1 is greater than the heat exchange area required by the second module A2. Therefore, the flow rate of the liquid-cooling channel 11 in the corresponding area of ​​the first module A1 needs to be greater than the flow rate of the liquid-cooling channel 11 in the corresponding area of ​​the second module A2. In order to reduce the flow rate of the liquid-cooling channel 11 in the corresponding area of ​​the second module A2, the cross-sectional area of ​​the connecting channel 13 in this area can be increased, so that the excess flow flows into the fire protection channel 12, thereby improving the uniformity of heat exchange.

[0086] In some embodiments, the battery box cover 100 further includes a first regulating mechanism, which is disposed in the first communicating flow channel 131. When the fire-fighting portion 14 is in a ruptured state, the first regulating mechanism is used to accelerate the coolant to flow into the fire-fighting flow channel 12. In this way, when the fire-fighting portion 14 is ruptured, the coolant can flow into the fire-fighting flow channel 12 at an accelerated speed under the action of the first regulating mechanism, so as to cool down the thermal runaway battery cell 300 and ensure the fire-fighting effect.

[0087] Furthermore, the battery box also includes a second regulating mechanism, which is arranged in the second connecting flow channel 132. When the fire-fighting part 14 is in an unbroken state, the second regulating mechanism is used to reduce the flow of coolant in the fire-fighting flow channel 12, and when the fire-fighting part 14 is in a broken state, the second regulating mechanism is used to accelerate the flow of coolant into the fire-fighting flow channel 12. In this way, when the fire-fighting part 14 is not broken, the second regulating mechanism can reduce the flow of coolant in the fire-fighting flow channel 12, so that more coolant is used for heat dissipation of the battery cell 300, and when the fire-fighting part 14 is broken, the second regulating mechanism can accelerate the flow of coolant into the fire-fighting flow channel 12 to cool down the thermal runaway battery cell 300 and ensure the fire-fighting effect.

[0088] It should be understood that in some other embodiments, the battery box cover 100 may include only the first adjustment mechanism without the second adjustment mechanism, or only the second adjustment mechanism without the first adjustment mechanism.

[0089] Specifically, the first regulating mechanism is a Tesla valve 20 disposed in the first communicating flow channel 131, and the coolant flows forward through the Tesla valve 20. In order to facilitate the installation of the Tesla valve 20, a first installation groove can be opened in the first communicating flow channel 131, and the Tesla valve 20 can be installed in the first installation groove. Fig.13 The core structure of the Tesla valve 20 includes a plurality of wing-shaped obstacles that can be bypassed when the fluid flows in the forward direction, allowing the fluid to flow unimpeded and gain an acceleration effect due to the flow pressure; see Fig.14 When the fluid flows in the reverse direction, it will encounter a wing-shaped obstacle every time it passes through a channel, which will lead to an enhanced backflow blocking effect and a significant increase in flow resistance. By setting the Tesla valve 20 in the first connecting flow channel 131, when the fire fighting part 14 is broken, the coolant can flow to the fire fighting flow channel 12 at an accelerated speed, thereby improving the fire fighting effect.

[0090] The second regulating mechanism is a Tesla valve 20 provided in the second connecting flow channel 132. In order to facilitate the installation of the Tesla valve 20, a second installation groove can be opened in the second connecting flow channel 132, and the Tesla valve 20 can be installed in the second installation groove. When the fire-fighting part 14 is in an unbroken state, the coolant flows through the Tesla valve 20 in the reverse direction. When the fire-fighting part 14 is in a broken state, the coolant flowing out of the liquid-cooling flow channel 11 flows through the Tesla valve 20 in the forward direction. When the fire-fighting part 14 is in an unbroken state, the coolant flowing out of the liquid-cooling flow channel 11 flows through the Tesla valve 20 in the reverse direction, and the fluid resistance increases, thereby achieving the effect of reducing the coolant flow rate in the fire-fighting flow channel 12. When the fire-fighting is in a broken state, the coolant can flow into the fire-fighting flow channel 12 at an accelerated speed, thereby improving the fire-fighting effect.

[0091] At the same time, a Tesla valve 20 is provided in the first connecting flow channel 131 and the second connecting flow channel 132 . When the fire-fighting part 14 is broken, the Tesla valve 20 can also reduce the reflux of the coolant into the liquid cooling flow channel 11 caused by the erupting gas.

[0092] It is conceivable that in some other embodiments, the first adjustment mechanism and the second adjustment mechanism may also adopt other configurations, as long as they can achieve the corresponding functions, and this is not limited in the present application.

[0093] Another embodiment of the present application further provides a battery box cover 100, which belongs to the above-mentioned battery pack 1000. Since the above-mentioned battery pack 1000 has beneficial effects, the battery box cover 100 belonging to the above-mentioned battery pack 1000 has the same beneficial effects, which will not be described in detail here.

[0094] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0095] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A battery box cover, characterized in that: include: A main body (10), wherein a liquid cooling channel (11), a fire fighting channel (12) and a connecting channel (13) are provided in the main body (10); the connecting channel (13) comprises a first connecting channel (131) and a second connecting channel (132); at least one of the fire fighting channels (12) is connected to the liquid cooling channel (11) through the first connecting channel (131), and is connected to the same liquid cooling channel (11) through the second connecting channel (132); the first connecting channel (131) and the second connecting channel (132) connected to the same fire fighting channel (12) are arranged correspondingly and respectively form a first connecting port (B) and a second connecting port (D) with the liquid cooling channel (11), and the first connecting port (B) is located upstream of the corresponding second connecting port (D); The main body (10) is used to form a fire-fighting portion (14) in an area of ​​the fire-fighting flow channel (12); the fire-fighting portion (14) can rupture when the battery cell (300) is thermally runaway, so that the coolant in the fire-fighting flow channel (12) is sprayed out.

2. The battery box cover according to claim 1, characterized in that: The ratio of the cross-sectional area of ​​the liquid cooling channel (11) to the cross-sectional area of ​​the connecting channel (13) is greater than or equal to 2.

5.

3. The battery box cover according to claim 1, characterized in that: The liquid cooling channel (11) comprises a plurality of sub-channels (111) that are interconnected, and the flow directions of two adjacent sub-channels (111) belonging to the same liquid cooling channel (11) are opposite, and one sub-channel (111) is located upstream of another sub-channel (111); at least one fire protection channel (12) is arranged between two adjacent sub-channels (111); the first connecting channel (131) and the upstream sub-channel (111) form the first connecting port (B), and the second connecting channel (132) and the downstream sub-channel (111) form the second connecting port (D); The first connecting port (B) is arranged at the end of the upstream sub-channel (111), and the second connecting port (D) is arranged at the end of the downstream sub-channel (111), so that the flow direction of the fire protection channel (12) is the same as that of the downstream sub-channel (111).

4. The battery box cover according to any one of claims 1 to 3, characterized in that: The battery box cover also includes a first regulating mechanism, which is disposed in the first communicating flow channel (131); when the fire-fighting portion (14) is in a ruptured state, the first regulating mechanism is used to accelerate the flow of coolant into the fire-fighting flow channel (12); and / or The battery box cover also includes a second regulating mechanism, which is arranged in the second connecting flow channel (132); when the fire-fighting part (14) is in an unbroken state, the second regulating mechanism is used to reduce the flow rate of the coolant in the fire-fighting flow channel (12); when the fire-fighting part (14) is in a broken state, the second regulating mechanism is used to accelerate the flow of the coolant into the fire-fighting flow channel (12).

5. The battery box cover according to claim 4, characterized in that: The first regulating mechanism is a Tesla valve (20) disposed in the first communicating flow channel (131), and the coolant flows through the Tesla valve (20) in a positive direction; and / or The second regulating mechanism is a Tesla valve (20) arranged in the second communicating flow channel (132); when the fire-fighting part (14) is in the unbroken state, the coolant flows through the Tesla valve (20) in the reverse direction, and when the fire-fighting part (14) is in the ruptured state, the coolant flows through the Tesla valve (20) in the forward direction.

6. The battery box cover according to claim 1, characterized in that: The main body (10) comprises a lower plate (15) and an upper plate (16), wherein the upper plate (16) covers the lower plate (15) and forms the liquid cooling channel (11), the communication channel (13) and the fire fighting channel (12) therebetween; The lower plate (15) is punched in a direction close to the upper plate (16) to form the punched weak portion, and the punched weak portion forms the fire protection portion (14). The height h1 of the punched weak portion and the depth h3 of the fire protection flow channel (12) satisfy the relationship: 0.3≤h1 / h3≤0.

8.

7. The battery box cover according to claim 1, characterized in that: The main body (10) comprises a lower plate (15) and an upper plate (16), wherein the upper plate (16) covers the lower plate (15) and forms the liquid cooling channel (11), the communication channel (13) and the fire fighting channel (12) therebetween; The lower plate (15) comprises a first groove portion (151) and a first straight portion (152), and the upper plate (16) comprises a second groove portion (161) and a second straight portion (162), wherein the first groove portion (151) and the second groove portion (161) have opposite concave directions; The first groove portion (151) and the second straight portion (162) form the liquid cooling channel (11), the first straight portion (152) and the second groove portion (161) form the fire fighting channel (12), and the fire fighting portion (14) is arranged on the first straight portion (152).

8. The battery box cover according to claim 7, characterized in that: The liquid cooling channel (11) comprises a plurality of sub-channels (111) that are interconnected, and the flow directions of two adjacent sub-channels (111) belonging to the same liquid cooling channel (11) are opposite, and one sub-channel (111) is located upstream of another sub-channel (111); at least one fire protection channel (12) is arranged between two adjacent sub-channels (111); the first connecting channel (131) and the upstream sub-channel (111) form the first connecting port (B), and the second connecting channel (132) and the downstream sub-channel (111) form the second connecting port (D); The fire-fighting flow channel (12) is used to correspond to the explosion-proof valve (302) of the battery cell (300), and the sub-flow channels (111) are respectively arranged on both sides of the fire-fighting flow channel (12), and at least two adjacent sub-flow channels (111) on one side and belonging to the same liquid-cooling flow channel (11) correspond to one pole (301) of the battery cell (300), and at least two adjacent sub-flow channels (111) on the other side and belonging to the same liquid-cooling flow channel (11) correspond to another pole (301) of the battery cell (300).

9. The battery box cover according to claim 8, characterized in that: A heat insulating member (500) is provided on a side of the first straight portion (152) away from the upper plate (16); the heat insulating member (500) is provided in an area where the first straight portion (152) and the second straight portion (162) overlap; the heat insulating member (500) is used to isolate the explosion-proof valve (302) and the pole (301) of the battery cell (300).

10. A battery pack, characterized in that: The battery box comprises a box body (200), a battery cell (300) and a battery box cover according to any one of claims 1 to 9; the battery cell (300) is installed in the box body (200), and the battery box cover is arranged on the box body (200); The liquid cooling channel (11) is opposite to the pole (301) of the battery cell (300), and the fire protection channel (12) is opposite to the explosion-proof valve (302) of the battery cell (300).

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