Battery box and battery pack

Abstract

The application relates to the technical field of batteries, and provides a battery box and a battery pack. The battery box comprises a bottom plate and a side wall. The side wall is surrounded on the circumferential side of the bottom plate to form a liquid cooling cavity for storing a battery module. The bottom plate is internally provided with an inlet cavity, the bottom plate is provided with a through gap for connecting the inlet cavity and the liquid cooling cavity, and the bottom plate is further provided with an inlet hole in communication with the inlet cavity. The cooling liquid is injected through the inlet hole, so that the cooling liquid can flow into the liquid cooling cavity through the inlet cavity and the through gap. Based on the fact that the battery module is stored in the liquid cooling cavity, the cooling liquid can be used for immersion liquid cooling of the battery module, so that the cooling effect is improved, the consistency of the temperatures of the battery cells in the battery module is improved, high-power discharge of the battery module can be realized, and the safety of the battery pack is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of batteries, in particular to a battery box and a battery pack. BACKGROUND

[0002] In the related art, the battery module is usually cooled by natural cooling, air cooling, phase change cooling or bottom liquid cooling plate cooling. The above cooling methods cannot meet the high-power discharge requirement of the battery module, and the temperature consistency between the battery cells is poor. SUMMARY

[0003] Embodiments of the present application provide a battery box and a battery pack, which can improve the technical problem of temperature consistency of battery cells and meet the high-power discharge requirement of the battery module.

[0004] In a first aspect, embodiments of the present application provide a battery pack, comprising:

[0005] a bottom plate;

[0006] a side wall enclosing a periphery of the bottom plate to form a liquid cooling cavity for storing a battery module;

[0007] wherein the bottom plate has a liquid inlet cavity, the bottom plate is provided with a through gap for connecting the liquid inlet cavity and the liquid cooling cavity, and the bottom plate is further provided with a liquid inlet hole communicating with the liquid inlet cavity.

[0008] In an embodiment, the bottom plate has a first side close to the liquid inlet hole and a second side away from the liquid inlet hole, wherein the liquid inlet hole is located on the first side, the through gap extends from the second side to the first side, and the through gap is spaced apart from the first side.

[0009] In an embodiment, the through gap is provided as at least two, and the at least two through gaps are spaced apart in a direction perpendicular to the first side to the second side, the liquid cooling cavity includes a first cooling zone close to the first side, a third cooling zone close to the second side, and a second cooling zone between the first cooling zone and the third cooling zone, wherein at least part of the through gaps extends from the third cooling zone to the first cooling zone.

[0010] In an embodiment, the first cooling zone, the second cooling zone and the third cooling zone segment all the through gaps, the number of segments located in the first cooling zone is L, the number of segments located in the second cooling zone is M, and the number of segments located in the third cooling zone is N, wherein L

[0011] In an embodiment, each of the segments in the first cooling zone has a width of D1, each of the segments in the second cooling zone has a width of D2, and each of the segments in the third cooling zone has a width of D3, wherein D1 < D2 ≤ D3.

[0012] Each of the through openings has a width of 10-30 mm.

[0013] In an embodiment, the bottom plate comprises:

[0014] The plate body and the plate cover are connected to enclose the recess and form the liquid inlet cavity, wherein the through opening is formed in the plate cover, the liquid inlet hole is formed in the plate body, and the liquid inlet hole communicates with the recess.

[0015] One of the plate body and the plate cover is provided with a protrusion, which is located in the recess when the plate body and the plate cover are connected, wherein the height of the protrusion is less than the depth of the recess.

[0016] In an embodiment, the protrusion comprises a first protrusion and a second protrusion formed in the plate body, wherein the first protrusion has a first equal-width section and a first tapering section with decreasing width along a direction from the first side to the second side, and the second protrusion has a second equal-width section and a second tapering section with decreasing width, and wherein at least two battery modules are arranged in the liquid cooling cavity in a spaced manner, and the spacing between the first equal-width section and the second equal-width section is adapted to the spacing between two adjacent battery modules.

[0017] In an embodiment, the battery box further comprises:

[0018] A box cover is arranged on the side wall to enclose the liquid cooling cavity.

[0019] The box cover has a liquid outlet channel, which communicates with the liquid cooling cavity.

[0020] The liquid outlet channel is formed with a communication hole at a position of the box cover close to the second side, and is formed with a liquid discharge hole at a position of the box cover close to the first side, and the cooling liquid flows into the liquid outlet channel from the communication hole and is discharged from the battery box through the liquid discharge hole.

[0021] In an embodiment, the liquid outlet channel and the communication hole are provided as at least two, each of the liquid outlet channels is formed with a communication hole on the box cover, at least two of the liquid outlet channels communicate with each other and are formed with a liquid discharge hole on the box cover, or at least two of the liquid outlet channels are arranged in a spaced manner and are formed with multiple liquid discharge holes on the box cover.

[0022] The at least two communication holes are arranged at intervals on the box cover.

[0023] In an embodiment, the liquid cooling cavity further comprises a filler, and a liquid cooling gap is left between the filler and the battery module, the filler abuts against the bottom plate and the side wall;

[0024] The width of the liquid cooling gap is 2-3 mm.

[0025] In a second aspect, embodiments of the present application provide a battery pack, comprising:

[0026] A battery module;

[0027] A battery box as described above;

[0028] The battery module is arranged in the liquid cooling cavity.

[0029] In an embodiment, along the direction from the first side to the second side of the bottom plate, the battery module comprises at least two electric cells arranged at intervals, and a partition is arranged between each two adjacent electric cells, the partition extends along a first direction, and the partition is arranged at intervals along a second direction, wherein the first direction is perpendicular to the second direction, a liquid cooling channel is formed between each two adjacent partitions and / or between the partition and the side wall, the liquid cooling channel communicates with the through-opening, and the width of the liquid cooling channel is adapted to the width of the segment in the third cooling area.

[0030] In an embodiment, along the direction from the first side to the second side, the battery module comprises electric cells arranged at intervals from the first side to the Sth electric cell, S is a natural number, and S≥3, wherein at least part of the through-opening is configured to extend from the second side to the position of the second electric cell.

[0031] In an embodiment, along the width direction of the box cover, the projection of the communication hole is located at the position between each two adjacent battery modules, and / or the projection of the communication hole is located at the position between the battery module and the side wall.

[0032] Along the length direction of the box cover, the projection of the communication hole is located at the position between the electric cell of the battery module and the end plate.

[0033] In an embodiment, the electric cell is connected with a copper bar, at least one copper bar penetrates through the side wall to supply power to an external electrical device, and a sealing unit is arranged at the connection position of the copper bar and the side wall.

[0034] The embodiments of the present application have the following beneficial effects:

[0035] In the embodiment of the present application, the cooling liquid is injected through the liquid inlet hole, and the cooling liquid can flow into the liquid cooling cavity through the liquid inlet cavity and the through gap, based on the battery module being stored in the liquid cooling cavity, the cooling liquid can perform immersion liquid cooling on the battery module, so as to improve the cooling effect and the consistency of the temperature of each cell in the battery module, the high-power discharge of the battery module can be realized, and the safety of the battery pack is improved. BRIEF DESCRIPTION OF DRAWINGS

[0036] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the embodiment description will be briefly introduced as follows. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor on the basis of these drawings.

[0037] Figure 1 is a perspective view of a battery pack provided by an embodiment of the present application;

[0038] Figure 2 is an exploded view of a battery pack provided by an embodiment of the present application;

[0039] Figure 3 is a perspective view of a battery box provided by an embodiment of the present application.

[0040] Figure 4 is a top view of a bottom plate provided by an embodiment of the present application.

[0041] Figure 5 is a perspective view of a plate body provided by an embodiment of the present application.

[0042] Figure 6 is a perspective view of a box cover provided by an embodiment of the present application.

[0043] Figure 7 is a perspective view of a battery module provided by an embodiment of the present application.

[0044] Figure 8 is Figure 7 is a partial enlarged view of position A in FIG. 8.

[0045] Figure 9 is a perspective view of a copper bar provided by an embodiment of the present application.

[0046] Figure 10 is a temperature change curve diagram of a battery pack provided by an embodiment of the present application.

[0047] Figure 11 is a cell temperature cloud chart of a battery pack provided by an embodiment of the present application.

[0048] Figure 12A watershed temperature cloud chart of the battery pack provided by an embodiment of the present application.

[0049] Figure 13 A temperature change curve chart of the battery pack in the related art.

[0050] Figure 14 A cell temperature cloud chart of the battery pack in the related art.

[0051] Figure 15 A watershed temperature cloud chart in the related art.

[0052] Reference signs:

[0053] 10-bottom plate, 120-conducting gap, 130-liquid inlet hole, 140-plate body, 150-plate cover, 160-groove, 170-first protruding part, 1710-first equal-width section, 1720-first tapered section, 180-second protruding part, 1810-second equal-width section, 1820-second tapered section, 20-side wall, 30-liquid cooling cavity, 310-first cooling zone, 320-second cooling zone, 330-third cooling zone, 40-box cover, 410-liquid outlet channel, 420-communication hole, 430-liquid outlet hole, 440-exhaust channel, 450-air inlet hole, 460-exhaust hole, 50-battery module, 510-cell, 520-separation strip, 530-copper bar, 540-sealing unit, 60-filling piece, 70-first side, 80-second side. DETAILED DESCRIPTION

[0054] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application. In addition, it should be understood that the specific embodiments described herein are only used to illustrate and explain the present application, and are not used to limit the present application. In the present application, the orientation words such as "upper" and "lower" generally refer to the upper and lower in the actual use or working state of the device, and specifically refer to the drawing direction in the drawings; and "inner" and "outer" refer to the contour of the device.

[0055] As shown in FIG. 1, an embodiment of the present application provides a battery box. The battery box comprises a bottom plate 10 and a side wall 20. The side wall 20 is enclosed on the peripheral side of the bottom plate 10 to form a liquid cooling cavity 30 for storing a battery module 50. The bottom plate 10 has a liquid inlet cavity therein, the bottom plate 10 is provided with a conducting gap 120 for connecting the liquid inlet cavity and the liquid cooling cavity 30, and the bottom plate 10 is further provided with a liquid inlet hole 130 communicating with the liquid inlet cavity. Figures 1 to 15 ​

[0056] In some embodiments, the cooling liquid is injected through the liquid inlet hole 130, and the cooling liquid can flow into the liquid cooling cavity 30 through the liquid inlet cavity and the through gap 120. Based on the battery module 50 being stored in the liquid cooling cavity 30, the cooling liquid can perform immersion liquid cooling on the battery module 50 to improve the cooling effect, improve the consistency of the temperature of each battery cell 510 in the battery module 50, and reduce the temperature difference between the battery cells 510 at both ends of the battery module 50. Thus, the high-power discharge of the battery module 50 can be realized, and the safety of the battery pack can be improved.

[0057] It can be understood that the cooling liquid can cool the battery module 50 placed on the bottom plate 10 through heat transfer after entering the liquid inlet cavity from the liquid inlet hole 130. After the cooling liquid fills the liquid inlet cavity, the cooling liquid will gradually overflow from the through gap 120 and enter the liquid cooling cavity 30. As the cooling liquid is continuously injected, the liquid level of the cooling liquid in the liquid cooling cavity 30 will gradually rise and eventually immerse the battery module 50. Thus, immersion cooling of the battery module 50 is realized.

[0058] Based on the way of from bottom to top to supplement the cooling liquid into the liquid cooling cavity 30, the cooling liquid can fill the liquid cooling cavity 30, and the cooling effect on the battery module 50 is ensured. Storing the battery module 50 in the liquid cooling cavity 30 can well improve the consistency of the temperature of each battery cell 510 in the battery module 50, and the battery module 50 can meet the requirement of high-power discharge.

[0059] The battery box is usually a cuboid, and the bottom plate 10 is usually a rectangular bottom plate 10, and the side wall 20 is four square plates surrounding the side of the bottom plate 10. The side wall 20 can be integrally formed with the bottom plate 10. The side wall 20 can also be assembled on the upper surface of the bottom plate 10 by fasteners. At this time, a sealing element needs to be arranged at the connection between the side wall 20 and the bottom plate 10. For example, a sealing ring is arranged at the connection between the side wall 20 and the bottom plate 10 by sealing glue.

[0060] In some embodiments, the bottom plate 10 has a first side 70 close to the liquid inlet hole 130 and a second side 80 away from the liquid inlet hole 130. The liquid inlet hole 130 is located on the first side 70, the through gap 120 extends from the second side 80 to the first side 70, and the through gap 120 is arranged spaced apart from the first side 70.

[0061] Based on the conductive gap 120 extending from the second side 80 to the first side 70, and the conductive gap 120 being spaced apart from the first side 70, no coolant will flow out near the liquid inlet hole 130. Here, the coolant enters the liquid cooling chamber 30 and flows there to obtain the coolant. As a result, the coolant can flow out first at a position away from the liquid inlet hole 130. Based on the coolant, the battery cells 510 of the battery module 50 near the liquid inlet hole 130 can be cooled by heat exchange, while the battery cells 510 away from the liquid inlet hole 130 can be immersed in cooling first, thereby improving the temperature consistency between the battery cells 510 in the battery module 50.

[0062] The direction from the first side 70 to the second side 80 is the length direction of the battery box, that is, the conductive gap 120 extends along the length direction of the battery box.

[0063] like Figure 3 As shown, in some embodiments, at least two conductive gaps 120 are provided, and along a direction perpendicular to the first side 70 to the second side 80 , at least two conductive gaps 120 are spaced apart.

[0064] By setting a plurality of conductive gaps 120 and spacing the plurality of conductive gaps 120 in a direction perpendicular to the first side 70 to the second side 80, coolant can flow out simultaneously at a plurality of positions of the base plate 10, which will make the cooling of the battery module 50 more uniform, and further improve the temperature consistency between the battery cells 510 in the battery module 50.

[0065] The direction perpendicular to the first side 70 to the second side 80 is the width direction of the battery box, that is, at least two conductive gaps 120 are spaced apart along the width direction of the battery box.

[0066] For example, the number of conductive gaps 120 is set to 10, and the 10 conductive gaps 120 are spaced apart along the width direction of the battery box. The length of each conductive gap 120 is the same or different, the width of each conductive gap 120 is the same or different, and the spacing between each two adjacent conductive gaps 120 is the same or different.

[0067] See also Figure 4 In some embodiments, the liquid-cooling chamber 30 includes a first cooling zone 310 near the first side 70, a third cooling zone 330 near the second side 80, and a second cooling zone 320 located between the first cooling zone 310 and the third cooling zone 330, wherein at least a portion of the conductive gap 120 extends from the third cooling zone 330 to the first cooling zone 310, at least a portion of the conductive gap 120 extends from the third cooling zone 330 to the second cooling zone 320, and at least a portion of the conductive gap 120 extends only within a certain length within the third cooling zone 330.

[0068] It can be understood that the first cooling area 310, the second cooling area 320 and the third cooling area 330 are sequentially communicated in the direction from the first side 70 to the second side 80. Based on the fact that part of the through gaps 120 extend to the first cooling area 310, the cooling liquid penetrating close to the first side 70 can be less, and the temperature difference between the first cooling area 310 and the third cooling area 330 and the battery cells 510 can be prevented from being too large.

[0069] Part of the through gaps 120 extend to the first cooling area 310, part of the through gaps 120 extend to the second cooling area 320, and part of the through gaps 120 extend to the third cooling area 330. Based on the fact that all the through gaps 120 extend from the direction of the third cooling area 330, all the through gaps 120 can penetrate the cooling liquid outward from the third cooling area 330. Since the third cooling area 330 is far away from the liquid inlet hole 130, most of the cooling liquid penetrates into the liquid cooling cavity 30 from the position far away from the liquid inlet hole 130, and a small part of the cooling liquid penetrates into the liquid cooling cavity 30 from the position close to the liquid inlet hole 130. Based on the flow direction of the cooling liquid in the liquid inlet cavity and the amount of cooling liquid penetrating the first cooling area 310, the second cooling area 320 and the third cooling area 330, the temperature difference between the battery cells 510 in the battery module 50 can be small, and the temperature consistency between the battery cells 510 in the battery module 50 can be improved.

[0070] Please continue to refer to Figure 4 In some embodiments, the first cooling area 310, the second cooling area 320 and the third cooling area 330 segment all the through gaps 120, the number of segments located in the first cooling area 310 is L, the number of segments located in the second cooling area 320 is M, and the number of segments located in the third cooling area 330 is N, wherein L

[0071] Based on the number distribution of the corresponding segments of the through gaps 120 in the first cooling area 310, the second cooling area 320 and the third cooling area 330, most of the cooling liquid penetrates into the liquid cooling cavity 30 from the position far away from the liquid inlet hole 130, and a small part of the cooling liquid penetrates into the liquid cooling cavity 30 from the position close to the liquid inlet hole 130. Based on the flow direction of the cooling liquid in the liquid inlet cavity and the amount of cooling liquid penetrating the first cooling area 310, the second cooling area 320 and the third cooling area 330, the temperature difference between the battery cells 510 in the battery module 50 can be small, and the temperature consistency between the battery cells 510 in the battery module 50 can be improved.

[0072] For example, the number of conductive gaps 120 can be set to 10, and the lengths of the 10 conductive gaps 120 can be the same or different. The first cooling zone 310, the second cooling zone 320, and the third cooling zone 330 can divide the 10 conductive gaps 120 into segments, with the number of segments in the first cooling zone 310 being 2, the number of segments in the second cooling zone 320 being 6, and the number of segments in the third cooling zone 330 being 10.

[0073] It is understandable that L, M, and N are all natural numbers, and reasonable values ​​of L, M, and N are selected based on actual conditions. Generally speaking, the value of N is equal to the number of conductive gaps 120 arranged.

[0074] like Figure 4 As shown, in some embodiments, the width of each segment in the first cooling zone 310 is D1, the width of each segment in the second cooling zone 320 is D2, and the width of each segment in the third cooling zone 330 is D3, wherein D1<D2≤D3.

[0075] It is understood that by setting the width of the segment located in the first cooling zone 310 to the minimum and the width of the segment located in the third cooling zone 330 to the maximum, the amount of coolant penetrating at a position away from the liquid inlet 130 can be increased, while the amount of coolant penetrating at a position close to the liquid inlet 130 can be reduced. As a result, the amount of coolant penetrating at a position close to the liquid inlet 130 can be further reduced, and the temperature difference between the battery cells 510 located close to the liquid inlet 130 and the battery cells 510 located away from the liquid inlet 130 can be better balanced, thereby improving the temperature consistency between the battery cells 510 in the battery module 50.

[0076] For example, the width of each segment located in the first cooling zone 310 is 10 mm, the width of each segment located in the second cooling zone 320 is 20 mm, and the width of each segment located in the third cooling zone 330 is 30 mm.

[0077] For example, the width of each segment in the first cooling zone 310 is 15 mm, and the width of each segment in the second cooling zone 320 and each segment in the third cooling zone 330 are both 30 mm.

[0078] In some embodiments, the width of each conductive gap 120 is 10 mm to 30 mm.

[0079] For example, the width of the conductive gap 120 is 10 mm, 15 mm, 20 mm, 25 mm, 30 mm, or any value therebetween.

[0080] It can be understood that the width of the through gap 120 is set to 10-30 mm. If the width of the through gap 120 is too large, exceeding 30 mm, the number of through gaps 120 that can be arranged on the bottom plate 10 will be reduced, thereby affecting the control of the permeation amount and the permeation speed of each region. If the width of the through gap 120 is too small, less than 10 mm, the permeation speed of the through gap 120 will be slow, which is not conducive to the cooling of the battery module 50.

[0081] As shown in Figures 3 to 5 In some embodiments, the bottom plate 10 includes a plate body 140 and a plate cover 150. At least one of the plate body 140 and the plate cover 150 is configured with a groove 160. The plate body 140 is connected with the plate cover 150 to close the groove 160 and form a liquid inlet cavity. The through gap 120 is configured on the plate cover 150, the liquid inlet hole 130 is configured on the plate body 140, and the liquid inlet hole 130 communicates with the groove 160.

[0082] Based on the groove 160 configured on the plate body 140 or the plate cover 150, when the plate cover 150 is connected with the plate body 140 to close the groove 160, a liquid inlet cavity is formed. Based on the liquid inlet hole 130 arranged on the plate body 140 and the liquid inlet hole 130 communicating with the groove 160, the cooling liquid can be injected into the groove 160 through the liquid inlet hole 130 and overflowed through the through gap 120 to cool the battery module 50.

[0083] After the cooling liquid is injected into the groove 160 from the liquid inlet hole 130, the liquid level of the cooling liquid in the groove 160 is continuously raised. Based on the continuous rise of the liquid level, the cooling liquid is overflowed from the through gap 120 to enter the liquid cooling cavity 30 to perform immersion cooling on the battery module 50.

[0084] The plate body 140 and the plate cover 150 can be connected with each other by fasteners, or the plate cover 150 can be bonded to the plate body 140 to achieve the connection of the two. The sealing of the connection between the plate body 140 and the plate cover 150 is sufficient.

[0085] The plate cover 150 is located above the plate body 140. When the groove 160 is arranged on the plate body 140, the groove opening of the groove 160 faces upward. When the groove 160 is arranged on the plate cover 150, the groove opening of the groove 160 faces downward.

[0086] As shown in Figure 5 In some embodiments, one of the plate body 140 and the plate cover 150 is configured with a protruding portion. When the plate body 140 is connected with the plate cover 150, the protruding portion is located in the groove 160. The height of the protruding portion is less than the depth of the groove 160.

[0087] Based on setting the protruding part and making the height of the protruding part less than the depth of the groove 160, the protruding part can occupy part of the depth space of the groove 160, but it does not close the groove 160, so that the cooling liquid can flow in the groove 160, and the use amount of the cooling liquid can be reduced.

[0088] For example, the protruding part can be arranged on the plate body 140. Alternatively, the protruding part can be arranged on the plate cover 150.

[0089] Please refer to Figure 5 In some embodiments, the plate body 140 is configured with a first protruding part 170 and a second protruding part 180 extending towards the plate cover 150, and the first protruding part 170 and the second protruding part 180 are arranged at intervals, wherein the height of the first protruding part 170 is less than the groove depth of the groove 160, and the height of the second protruding part 180 is less than the groove depth of the groove 160.

[0090] It can be understood that, based on the first protruding part 170 and the second protruding part 180 being arranged on the plate body 140, and the height of the first protruding part 170 being less than the groove depth of the groove 160 and the height of the second protruding part 180 being less than the groove depth of the groove 160, the first protruding part 170 and the second protruding part 180 can occupy part of the depth space of the groove 160, but it does not close the groove 160, so that the cooling liquid can flow in the groove 160, and the use amount of the cooling liquid can be reduced.

[0091] Based on the cooling liquid first filling the groove 160, and then overflowing from the upper through gap 120, when the first protruding part 170 and the second protruding part 180 occupy a certain height of the groove 160, the liquid inlet cavity can flow out from the through gap 120 with less cooling liquid, so as to reduce the use amount of the cooling liquid and reduce the cost.

[0092] For example, the height of the first protruding part 170 and the second protruding part 180 is 1 mm, and the groove depth of the groove 160 is 2 mm. Of course, the height of the first protruding part 170 and the second protruding part 180 and the groove depth of the groove 160 can be reasonably selected based on the model, size, use scene, etc. of the battery box, so that the groove depth of the groove 160 is greater than the height of the first protruding part 170 and the second protruding part 180.

[0093] Please continue to refer to Figure 5In some embodiments, along the direction from the first side 70 to the second side 80, the first protruding portion 170 has a first equal-width section 1710 and a first tapered section 1720 with decreasing width, and the second protruding portion 180 has a second equal-width section 1810 and a second tapered section 1820 with decreasing width, wherein the liquid cooling cavity 30 stores at least two battery modules 50 spaced apart, and the spacing between the first equal-width section 1710 and the second equal-width section 1810 is adapted to the spacing between the adjacent two battery modules 50.

[0094] Based on the design of the first equal-width section 1710, the first tapered section 1720, the second equal-width section 1810, and the second tapered section 1820, the liquid cooling cavity can have less cooling liquid near the liquid inlet hole 130 region and more cooling liquid away from the liquid inlet hole 130 region. In combination with the aforementioned flow direction of the cooling liquid in the liquid cooling cavity and the amount of permeated cooling liquid in the first cooling area 310, the second cooling area 320, and the third cooling area 330, the temperature difference between the battery cells 510 in the battery module 50 can be smaller, and the temperature consistency between the battery cells 510 in the battery module 50 can be further improved.

[0095] Specifically, the first protruding portion 170 and the second protruding portion 180 are both trapezoidal protruding portions, and the short sides of the first protruding portion 170 and the second protruding portion 180 are oppositely arranged. The first protruding portion 170 and the second protruding portion 180 are both protruding structures integrally formed on the plate body 140.

[0096] The first equal-width section 1710 and the second equal-width section 1810 can extend from the first side 70 to the position of the fourth battery cell. This is to prevent the first equal-width section 1710 and the second equal-width section 1810 from being too long, which would cause excessive material consumption of the first protruding portion 170 and the second protruding portion 180, and thus reduce the manufacturing cost of the first protruding portion 170 and the second protruding portion 180.

[0097] The spacing between the first equal-width section 1710 and the second equal-width section 1810 is the same as the spacing between the adjacent two battery modules 50. Since the two battery modules 50 do not need to be directly injected with cooling liquid for heat dissipation, the bottom plate 10 does not need to be provided with a through gap 120 between the two battery modules 50. Thus, this position does not need to be processed in the groove 160, thereby saving the manufacturing cost of the bottom plate 10.

[0098] Based on the spacing arrangement of the first protruding portion 170 and the second protruding portion 180, the manufacturing cost of the bottom plate 10 and the usage cost of the cooling liquid can be reasonably reduced, thereby reducing the manufacturing cost of the battery box and the battery pack.

[0099] As Figure 2 and Figure 6As shown, in some embodiments, the battery box further comprises a box cover 40. The box cover 40 covers the side wall 20 to enclose the liquid cooling cavity 30. Among them, the box cover 40 has a liquid outlet passage 410 which communicates with the liquid cooling cavity 30.

[0100] It can be understood that the box cover 40 covers the side wall 20 to enclose the liquid cooling cavity 30 on the one hand, so as to carry out immersion cooling in a closed environment and prevent the cooling liquid from overflowing from the side wall 20. On the other hand, the box cover 40 is provided with a liquid outlet passage 410 to discharge the heat-exchanged cooling liquid, so that the low-temperature cooling liquid can be continuously injected into the liquid cooling cavity 30.

[0101] Among them, the liquid outlet passage 410 and the liquid inlet hole 130 can be communicated through a liquid cooling circulation pipeline, so as to realize the circulation use of the refrigerant. Among them, the liquid cooling circulation pipeline is provided with a refrigeration device, so as to cool the high-temperature cooling liquid.

[0102] Among them, the plate cover 150 can be fixed to the side wall 20 through fasteners, and the connection part of the two has a sealing element. For example, an annular groove is formed on the upper surface of the side wall 20, and a sealing ring is clamped in the annular groove. After the plate cover 150 covers the side wall 20, the plate cover 150 presses the sealing ring, so that the plate cover 150 and the side wall 20 are sealingly connected.

[0103] In some embodiments, the liquid outlet passage 410 is formed with a communication hole 420 at a position close to the second side 80 of the box cover 40, and the liquid outlet passage 410 is formed with a liquid discharge hole 430 at a position close to the first side 70 of the box cover 40. The cooling liquid flows into the liquid outlet passage 410 from the communication hole 420 and is discharged from the battery box through the liquid discharge hole 430.

[0104] The cooling liquid flows into the liquid outlet passage 410 from the communication hole 420 and is discharged from the battery box through the liquid discharge hole 430. Since the liquid discharge hole 430 is located on the first side 70, the liquid discharge hole 430 and the liquid inlet hole 130 can be located on the same side, so that the liquid cooling pipeline is arranged conveniently. At the same time, since the liquid discharge hole 430 is located on the side away from the liquid inlet hole 130, the high-temperature cooling liquid after one round of cooling can be discharged from the side away from the liquid inlet hole 130, so as to prevent the high-temperature cooling liquid from being too close to the liquid inlet hole 130 and affecting the cooling effect.

[0105] Please refer to Figure 6 In some embodiments, the liquid outlet passage 410 and the communication hole 420 are each provided as at least two. Each liquid outlet passage 410 is formed with a communication hole 420 on the box cover 40. The at least two liquid outlet passages 410 are communicated and form a liquid discharge hole 430 on the box cover 40. Alternatively, the at least two liquid outlet passages 410 are arranged at intervals and form a plurality of liquid discharge holes 430 on the box cover 40.

[0106] Because the connecting holes 420 are located on the side away from the liquid inlet 130, rapid discharge of the high-temperature coolant is ensured. By having a greater number of connecting holes 420 than the number of battery modules 50, backflow of the high-temperature coolant, which could occur if there were fewer connecting holes 420, is prevented. This ensures rapid discharge of the high-temperature coolant and prevents slow discharge of the high-temperature coolant, which could affect the cooling effect.

[0107] The multiple outlet channels 410 can converge into a drain hole 430 and then be discharged from the battery box together. Thus, only one pipe connected to the surface of the battery box is required to complete the recovery of all high-temperature coolant.

[0108] Of course, the plurality of liquid outlet channels 410 may flow to different liquid drainage holes 430 respectively, so that each liquid outlet channel 410 corresponds to a liquid drainage hole 430 .

[0109] In some embodiments, at least two communication holes 420 are spaced apart on the tank cover 40. High-temperature coolant in different areas can be quickly discharged through the multiple spaced communication holes 420 to prevent the high-temperature coolant from flowing back and affecting the subsequent cooling effect.

[0110] For example, the orthographic projection of the connecting hole 420 can be located between two battery modules, so that the high-temperature coolant after cooling the two battery modules 50 can be directly and quickly discharged from the connecting hole 420, thereby preventing the high-temperature coolant from flowing back and affecting the subsequent cooling effect.

[0111] like Figure 6 As shown, in some embodiments, an exhaust channel 440 is further constructed in the box cover 40, and an air inlet hole 450 connected to the exhaust channel 440 is formed on the side of the box cover 40 facing the base plate 10, and an exhaust hole 460 is formed at a position close to the second side 80 of the box cover 40, wherein the box cover 40 is in contact with the battery module 50 through a seal to discharge exhaust gas through the air inlet hole 450, the exhaust channel 440 and the exhaust hole 460.

[0112] The exhaust channel 440 in the box cover 40 is used to discharge tail gas and waste gas generated when the battery cell 510 fails, so as to prevent the tail gas from entering the liquid cooling chamber 30 and contaminating the coolant.

[0113] Among them, the exhaust hole 460 is located on the side away from the liquid inlet hole 130, so the exhaust hole 460 is arranged on the opposite side of the liquid inlet hole 130 and the liquid discharge hole 430, which can keep the exhaust gas away from the liquid cooling pipe and facilitate the arrangement of the exhaust gas pipe.

[0114] The box cover 40 is provided with a seal at the position of the air inlet 450. When the box cover 40 is closed on the side wall 20, the seal is squeezed to form a good sealing effect. Specifically, the box cover 40 abuts against the explosion-proof valve of the battery cell 510 of the battery module 50 through the seal.

[0115] As shown in the drawings, in some embodiments, the liquid cooling cavity 30 is further provided with a filler 60, and a liquid cooling gap is left between the filler 60 and the battery module 50, and the filler 60 abuts against the bottom plate 10 and the side wall 20. Figure 2

[0116] By arranging the filler 60 in the liquid cooling cavity 30, the filler 60 can reduce the distance between the battery module 50 and the side wall 20, thereby reducing the internal space of the battery box, and the liquid cooling cavity 30 can be filled with less coolant, thereby reducing the amount of coolant and the cost. At the same time, the liquid cooling gap formed between the filler 60 and the battery module 50 can also guide the flow of the coolant, so that the coolant can flow along the liquid cooling gap, and the flow direction of the coolant can be easily controlled.

[0117] In some embodiments, the width of the liquid cooling gap is 2-3 mm.

[0118] It can be understood that a too wide liquid cooling gap requires more coolant to fill the liquid cooling cavity 30, resulting in excessive amount of coolant and increased cost. A too narrow liquid cooling gap can result in insufficient amount of coolant in the liquid cooling cavity 30, causing poor cooling effect of the battery module 50. Controlling the width of the liquid cooling gap within a reasonable range can reduce the cost while ensuring the liquid cooling effect.

[0119] For example, the width of the liquid cooling gap is 2 mm, 2.5 mm or 3 mm, or any value between any two of them.

[0120] In some embodiments, the filler 60 is bonded to the bottom plate 10 and the side wall 20. The filler 60 is fixed to the bottom plate 10 and the side wall 20 by bonding to prevent the filler 60 from moving in the liquid cooling cavity 30 and ensure the cooling effect of the battery module 50.

[0121] It can be understood that if the position of the filler 60 is not fixed, the filler 60 can float up and down or left and right when the liquid cooling cavity 30 is filled with coolant. If the filler 60 floats left and right to reduce the liquid cooling gap, the cooling effect of the battery module 50 will be affected.

[0122] On the other hand, the present application also provides a battery pack. The battery pack comprises a battery module 50 and a battery box according to the foregoing embodiments. The battery module 50 is arranged in the liquid cooling cavity 30.

[0123] ​In some embodiments, the cooling liquid is injected through the liquid inlet hole 130, and the cooling liquid can flow into the liquid cooling cavity 30 through the liquid inlet cavity and the through gap 120. Based on the battery module 50 being stored in the liquid cooling cavity 30, the cooling liquid can be used for immersion liquid cooling of the battery module 50, so as to improve the cooling effect and improve the consistency of the temperature of each battery cell 510 in the battery module 50. The high-power discharge of the battery module 50 can be realized, and the safety of the battery pack is improved.

[0124] As shown in Figure 7 and Figure 8 In some embodiments, a partition strip 520 is arranged between each two adjacent battery cells 510. The partition strip 520 extends along a first direction, and the partition strips 520 are arranged in at least two rows along a second direction. The first direction is perpendicular to the second direction. A liquid cooling channel is formed between each two adjacent partition strips 520 and / or between the partition strip 520 and the side wall 20. The liquid cooling channel is in communication with the through gap 120, and the width of the liquid cooling channel is adapted to the width of the segment of the through gap 120 located in the third cooling area 330.

[0125] The partition strip 520 can be bonded to the battery cell 510. Based on the arrangement of the partition strip 520, the two adjacent battery cells 510 are spaced apart. Based on the liquid cooling channel being formed between the two adjacent partition strips 520 or between the partition strip 520 and the side wall 20, the liquid cooling channel is in communication with the through gap 120. Therefore, the cooling liquid overflowing from the through gap 120 will directly flow into the liquid cooling channel and cool the battery cells 510 on both sides. When the liquid cooling channel is filled with the cooling liquid, the cooling liquid will gradually penetrate into the remaining area of the liquid cooling cavity 30. When all areas in the liquid cooling cavity 30 are filled with the cooling liquid, the cooling liquid will flow from the communication hole 420 into the liquid outlet channel 410 and be discharged from the battery box through the liquid outlet hole 430.

[0126] Since the segment located in the third cooling area 330 is the widest part of the through gap 120, the width of the liquid cooling channel is the same as the width of the segment located in the third cooling area 330. Therefore, the cooling liquid overflowing from the first cooling area 310, the second cooling area 320 and the third cooling area 330 can directly flow into the cooling channel.

[0127] As shown in Figure 7 The first direction is the height direction of the battery module 50, and the second direction is the width direction of the battery module 50.

[0128] In some embodiments, along the direction from the first side 70 to the second side 80, the battery module 50 comprises one to S number of battery cells arranged in sequence and spaced apart. The battery cell 510 close to the first side 70 is the first number of battery cell, and the battery cell 510 close to the second side 80 is the S number of battery cell. S is a natural number, and S≥3. At least part of the through gap 120 is arranged to extend from the second side 80 to the position of the second number of battery cell.

[0129] By extending at least part of the through gaps 120 to the position of the second-positioned battery cell, the farthest distance that the cooling liquid can permeate in the through gaps 120 is the position of the second-positioned battery cell in the direction from the second side 80 to the first side 70. Thus, it is ensured that the cooling liquid cannot permeate into the liquid cooling cavity 30 from the position of the first-positioned battery cell, thereby preventing the temperature difference between the first-positioned battery cell and the second-positioned battery cell from being too large.

[0130] In the case that at least part of the through gaps 120 extend to the position of the second-positioned battery cell, the cooling liquid permeating out of the through gaps 120 can directly cool the battery cell 510 at the large face.

[0131] It can be understood that the through gap 120 extending from the second side 80 to the position of the second-positioned battery cell is the longest through gap 120, and the rest of the through gaps 120 do not extend to the position of the second-positioned battery cell.

[0132] For example, the through gaps 120 are provided as 10, and the battery cells 510 are provided as 8, wherein 2 of the through gaps 120 extend from the second side 80 to the position of the second-positioned battery cell, 4 of the through gaps 120 extend from the second side 80 to the position of the fourth-positioned battery cell, and 6 of the through gaps 120 extend from the second side 80 to the position of the sixth-positioned battery cell.

[0133] In the case that S can be understood as the number of battery cells 510 contained in the battery module 50. For example, S = 9, and the battery module 50 includes 9 battery cells 510 arranged at intervals. In the direction from the first side 70 to the second side 80, the 9 battery cells 510 are respectively a first-positioned battery cell, a second-positioned battery cell, …, and a ninth-positioned battery cell.

[0134] In some embodiments, the projection of the communication hole 420 is located between every two adjacent battery modules 50 in the width direction of the tank cover 40, and / or the projection of the communication hole 420 is located between the battery module 50 and the side wall 20.

[0135] By arranging the projection of the communication hole 420 between the two battery modules 50, the high-temperature cooling liquid after cooling the two battery modules 50 can be directly discharged from the communication hole 420 quickly, thereby preventing the high-temperature cooling liquid from flowing back and affecting the subsequent cooling effect.

[0136] By arranging the projection of the communication hole 420 between the battery module 50 and the side wall 20, the high-temperature cooling liquid after cooling the edge battery module 50 can be directly discharged from the communication hole 420 quickly, thereby preventing the high-temperature cooling liquid from flowing back and affecting the subsequent cooling effect.

[0137] In some embodiments, along the width direction of the box cover 40, the communication holes 420 are arranged at intervals as P, and the liquid cooling cavity 30 stores Q battery modules 50 at intervals, where P = Q + 1.

[0138] By making the number of communication holes 420 greater than the number of battery modules 50, and based on the position distribution relationship between the communication holes 420 and the battery modules 50, it can be ensured that the high-temperature cooling liquid after cooling each battery module 50 can be quickly discharged, preventing the high-temperature cooling liquid from flowing back and affecting the subsequent cooling effect.

[0139] For example, the liquid cooling cavity 30 stores 2 battery modules 50, and the liquid outlet channel 410 is provided as 3, and the number of communication holes 420 is provided as 3. Based on the width of the battery box, the number of battery modules 50 stored in the liquid cooling cavity 30 is reasonably selected, so that the number of communication holes 420 is correspondingly set. The specific number of the two is not limited in the embodiments of the application.

[0140] In some embodiments, along the length direction of the box cover 40, the communication holes 420 are located at the position between the battery core 510 and the end plate of the battery module 50.

[0141] The communication holes 420 are arranged between the battery core 510 and the end plate of the battery module 50, so that the high-temperature cooling liquid after cooling the battery module 50 can be quickly discharged from the communication holes 420, and will not flow to the end plate and the position further back, which can prevent the high-temperature cooling liquid from flowing back and affecting the subsequent cooling effect.

[0142] In some embodiments, the distance between each adjacent two battery cores 510 is 2.5-3.5 mm.

[0143] It can be understood that the distance between the two battery cores 510 cooperates with the width of the through gap 120, which can determine the cross-sectional size of the liquid cooling channel between the battery cores 510. Since the width of the liquid cooling channel is the same as the width of the segment located in the third cooling area 330, that is, the interval distance between the adjacent two partitions in the second direction depends on the width of the third channel. At this time, it is necessary to control the distance between the two battery cores 510 to reasonably set the cross-sectional size of the liquid cooling channel. The cross-sectional size of the liquid cooling channel is controlled within a reasonable range, so as to ensure the liquid cooling effect, and not to waste the cooling capacity of the cooling liquid, and not to waste the internal space of the battery box. Therefore, the distance between each adjacent two battery cores 510 is 2.5-3.5 mm.

[0144] When the distance between each adjacent two battery cores 510 is less than 2.5 mm, the width of the liquid cooling channel is relatively narrow, which will cause less cooling liquid to be filled in the liquid cooling channel, affecting the cooling effect of the battery core 510.

[0145] When the distance between each two adjacent battery cells 510 is greater than 3.5 mm, the width of the liquid cooling channel is too wide, which will waste some of the cooling capacity of the coolant in the liquid cooling channel and cause the battery module 50 to occupy too much internal space of the battery box, resulting in space waste.

[0146] For example, the distance between each two adjacent battery cells 510 is 2.5 mm, 3 mm, 3.5 mm, or any value in between.

[0147] The distance between each two adjacent battery cells 510 corresponds to the thickness of the spacer 520 . Based on the distance between each two adjacent battery cells 510 , a spacer 520 of corresponding thickness is reasonably selected so that both sides of the spacer 520 are respectively bonded between the two adjacent battery cells 510 .

[0148] like Figure 9 As shown, in some embodiments, a copper busbar 530 is connected to the battery cell 510 , and at least one copper busbar 530 passes through the side wall 20 to supply power to external electrical devices, wherein a sealing unit 540 is provided at the connection between the copper busbar 530 and the side wall 20 .

[0149] Copper busbars 530 are used to electrically connect the battery cells 510 and to power external electrical components. The copper busbars 530 at the outermost edge of the battery compartment extend through the sidewalls 20 to provide power to external components. Sealing units 540 are installed at the junctions between the copper busbars 530 and the sidewalls 20 to ensure a tight seal and prevent coolant leakage.

[0150] Since the copper busbar 530 will also be immersed in the coolant, in order to prevent faults such as short circuits, an insulating coolant is used as the coolant.

[0151] like Figures 10 to 15 As shown, when the ambient temperature is 25°C (degrees Celsius), the coolant flow rate is 5L / min (liters per minute), and the coolant temperature is 20°C, the battery pack is first charged and then discharged at 1C times, and then rests for 30 minutes, and the cycle is repeated once. It can be seen that in the cooling method in the related art, the maximum temperature of the temperature monitoring point in the battery pack is 42.4°C, and the maximum temperature difference between the battery cells 510 is 4.8°C. The battery module 50 is cooled by the solution in the present application, and the maximum temperature of the temperature monitoring point in the battery pack is 28.6°C, and the maximum temperature difference between the battery cells 510 is 2.3°C. It can be seen that the maximum temperature of the battery cell 510 can be greatly reduced, and the temperature difference between the battery cells 510 can be reduced.

[0152] In addition, the cooling liquid required in the cooling process of the related art is about 12 L. However, in the present application, based on the presence of the filling structure, the amount of cooling liquid used is only 5.5 L, which reduces the amount of cooling liquid used by 54%.

[0153] The above has carried out the detailed introduction to the embodiment of the application, the principle and implementation mode of the application have been described by applying specific examples in this paper, the above embodiment description is only used for helping understanding the method of the application and its core idea; at the same time, for the person skilled in the art, according to the idea of the application, there will be changes in specific implementation mode and application range, and the above is described, the content of the specification should not be understood as the limitation of the application.

Claims

1. A battery box, characterized in that: include: base plate; Side walls, enclosing the periphery of the bottom plate to form a liquid cooling chamber for storing the battery module; The bottom plate has a liquid inlet cavity, the bottom plate is configured with a conducting notch for connecting the liquid inlet cavity and the liquid cooling cavity, and the bottom plate is further configured with a liquid inlet hole communicating with the liquid inlet cavity; The bottom plate has a first side close to the liquid inlet hole and a second side away from the liquid inlet hole, the conductive gap extends in a direction from the second side to the first side, and the conductive gap is spaced apart from the first side; At least two conductive gaps are provided, and at least two conductive gaps are spaced apart in a direction perpendicular to the first side to the second side. The liquid cooling chamber includes a first cooling zone near the first side, a third cooling zone near the second side, and a second cooling zone located between the first cooling zone and the third cooling zone, wherein at least some of the conductive gaps extend from the third cooling zone to the first cooling zone. The first cooling zone, the second cooling zone and the third cooling zone segment all the conductive gaps. The number of segments in the first cooling zone is L, the number of segments in the second cooling zone is M, and the number of segments in the third cooling zone is N, wherein L<M<N.

2. The battery box according to claim 1, characterized in that: The width of each segment located in the first cooling zone is D1, the width of each segment located in the second cooling zone is D2, and the width of each segment located in the third cooling zone is D3, wherein D1<D2≤D3; The width of each conductive gap is 10 mm to 30 mm.

3. The battery box according to claim 1 or 2, characterized in that: The bottom plate comprises: A plate body and a plate cover, at least one of the plate body and the plate cover is configured with a groove, the plate body and the plate cover are connected to close the groove and form the liquid inlet cavity, wherein the conducting notch is configured in the plate cover, the liquid inlet hole is configured in the plate body, and the liquid inlet hole is connected to the groove; One of the plate body and the plate cover is configured with a protrusion, and when the plate body and the plate cover are connected, the protrusion is located in the groove, wherein the height of the protrusion is less than the depth of the groove.

4. The battery box according to claim 3, characterized in that: The protrusion includes a first protrusion and a second protrusion constructed on the plate body, wherein, along the direction from the first side to the second side, the first protrusion has a first equal-width section and a first tapered section with decreasing width, and the second protrusion has a second equal-width section and a second tapered section with decreasing width, wherein at least two battery modules distributed at intervals are stored in the liquid-cooling chamber, and the spacing between the first equal-width section and the second equal-width section is adapted to the spacing between two adjacent battery modules.

5. The battery box according to claim 1 or 2, characterized in that: The battery box also includes: a box cover, covering the side wall to close the liquid cooling chamber; Wherein, the box cover has a liquid outlet channel, and the liquid outlet channel is connected to the liquid cooling cavity; The liquid outlet channel is formed with a connecting hole at a position of the box cover close to the second side, and the liquid outlet channel is formed with a drainage hole at a position of the box cover close to the first side. The coolant flows into the liquid outlet channel from the connecting hole and is discharged from the battery box through the drainage hole.

6. The battery box according to claim 5, characterized in that: There are at least two liquid outlet channels and at least two communicating holes, each of which has a communicating hole formed on the box cover. At least two liquid outlet channels are connected to form a drainage hole on the box cover, or at least two liquid outlet channels are spaced apart and multiple drainage holes are formed on the box cover. Wherein, the at least two communicating holes are arranged at intervals on the box cover.

7. The battery box according to claim 1 or 2, characterized in that: A filling piece is further provided in the liquid cooling cavity, a liquid cooling gap is left between the filling piece and the battery module, and the filling piece abuts against the bottom plate and the side wall; Wherein, the width of the liquid cooling gap is 2 mm to 3 mm.

8. A battery pack, characterized in that: include: Battery modules; The battery box according to any one of claims 1 to 7; Wherein, the battery module is arranged in the liquid cooling chamber.

9. The battery pack according to claim 8, characterized in that: Along the direction from the first side to the second side of the base plate, the battery module includes at least two spaced-apart battery cells, and a partition bar is provided between each two adjacent battery cells, the partition bar extends along the first direction, and the partition bars are spaced at least two along the second direction, wherein the first direction is perpendicular to the second direction, and a liquid cooling channel is formed between each two adjacent partition bars and / or between the partition bar and the side wall, the liquid cooling channel is connected to the conductive gap, and the width of the liquid cooling channel is adapted to the width of the segment of the conductive gap located in the third cooling zone.

10. The battery pack according to claim 8, wherein: Along the direction from the first side to the second side, the battery module includes battery cells No. 1 to No. S arranged in sequence, where S is a natural number and S≥3, wherein at least part of the conductive gap is configured to extend from the second side to the position of the battery cell No.

2.

11. The battery pack according to claim 8, characterized in that: Along the width direction of the box cover, the orthographic projection of the connecting hole of the box cover is located between each two adjacent battery modules, and / or the orthographic projection of the connecting hole is located between the battery module and the side wall; Wherein, along the length direction of the box cover, the orthographic projection of the communication hole is located between the battery cell and the end plate of the battery module.

12. The battery pack according to claim 9, wherein: The battery core is connected to a copper busbar, and at least one of the copper busbars passes through the side wall to supply power to external electrical devices. A sealing unit is provided at the connection between the copper busbar and the side wall.

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