Battery pack

Abstract

The battery pack has the height direction, the battery pack comprises a box body assembly, the box body assembly comprises a box main body and a box cover body, the box main body comprises a bottom wall and a side wall surrounding the periphery of the bottom wall, the bottom wall and the side wall are matched to define a containing cavity with one end being an opening, and the box cover body covers the opening in the height direction; a limiting groove is formed in the side, facing the box cover body, of the bottom wall and extends in the height direction. The flow channel cover body is matched with the bottom wall and the side wall to define a cooling cavity, and a first through hole is formed in the flow channel cover body; the single batteries are arranged in the first through holes in a penetrating manner, at least parts of the single batteries are located in the cooling cavities, and the bottoms of the single batteries are embedded in the limiting grooves. The single batteries are jointly limited by the tops and the bottoms respectively, the single batteries can be kept in a stable state when subjected to scouring force or tremor force of the cooling medium, and the sealing structures between the single batteries and the first through holes are prevented from being damaged, so that the connection between the single batteries and the box body is more reliable.

Description

Technical Field

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

[0002] Power batteries are the core power source in the new energy field and are widely used in new energy vehicles. With the rapid development of fast charging and super charging technologies, while achieving high current charging of power batteries, it also brings about rapid heating of single cells.

[0003] At present, some technologies use immersion cooling to achieve temperature control of single cells. Its basic structure includes a box body, a cooling channel in the box body, and a liquid inlet and a liquid outlet on the box body, which are connected to the cooling channel respectively. The single cell is inserted into the box body so that the single cell is partially immersed in the box body, so that the cooling medium directly contacts the outer wall of the single cell to achieve cooling. The above scheme adopts direct contact heat conduction and greatly increases the heat dissipation area of ​​the single cell to improve the cooling efficiency.

[0004] The single cell is partially immersed in the cooling medium, and one end of the single cell with the pole ear needs to be placed outside the cooling channel, so the side wall of the single cell needs to be sealed with the box. The common sealing method at present is low-power welding or glue fixing, which can achieve sealing and fix the single cell at the same time.

[0005] However, when one end of the single battery is placed in the cooling channel, the only connection between the single battery and the box is the sealing area. When the cooling medium flows in the cavity or the vehicle is in a bumpy condition, it will give the single battery a flushing force perpendicular to the axis of the single battery, which makes the single battery prone to shaking along its own axis, which may cause the risk of tearing and damage to the sealing area during long-term use, reducing service life and reliability. Utility Model Content

[0006] The present application provides a battery pack to solve the current technical problem that single cells are not fixed firmly and reliably when immersion cooling is adopted.

[0007] The present application provides a battery pack, the battery pack having a height direction, comprising:

[0008] A box assembly, comprising a box body and a box cover body, wherein the box body comprises a bottom wall and a side wall arranged around the outer periphery of the bottom wall, wherein the bottom wall and the side wall cooperate to enclose a receiving cavity with an open end, wherein the box cover body covers the open end along the height direction, and a limiting groove is arranged on a side of the bottom wall facing the box cover body, wherein the limiting groove extends along the height direction;

[0009] A flow channel cover body is disposed in the accommodating cavity, the flow channel cover body cooperates with the bottom wall and the side wall to enclose a cooling cavity, and the flow channel cover body is provided with a first through hole;

[0010] A single cell battery is inserted into the first through hole and at least a portion of the single cell battery is located in the cooling cavity, and a bottom of the single cell battery is embedded in the limiting groove.

[0011] To implement the above technical solution, when the single cell is installed, its top is sealed and fixed to the first through hole, and the bottom of the single cell in the cooling chamber is limited by the limiting groove, so that the contact area of ​​the single cell is increased. The single cell is limited by the top and bottom respectively, and can maintain a relatively stable state when the single cell is subjected to the flushing force or vibration force of the cooling medium, so as to avoid the sealing structure between the single cell and the first through hole from being damaged, so that the connection between the single cell and the box body is more reliable.

[0012] As one of the optional embodiments of the present application, a limiting protrusion is provided on the surface of the bottom wall facing the box cover body, the limiting protrusion extends along the height direction, and the limiting protrusion and the bottom wall are combined to form the limiting groove.

[0013] To implement the above technical solution, a limit groove structure is provided, which can increase the extension length of the limit groove in the height direction to increase the contact area between the limit groove and the single battery. The fixation of the limit protrusion and the fixation of the first through hole work together to enable the single battery to remain in a relatively stable state when subjected to the flushing force.

[0014] As one of the optional implementation schemes of the present application, a stabilizing sleeve is further provided on one side of the flow channel cover body facing the bottom wall, the stabilizing sleeve extends along the height direction, and the stabilizing sleeve is provided on the outer peripheral side of the single battery.

[0015] To implement the above technical solution, the stabilizing sleeve and the limiting protrusion are respectively close to the two ends of the single battery, and the synergistic limiting effect further improves the stability of the single battery fixation.

[0016] As one of the optional implementation schemes of the present application, there is a gap between the limiting protrusion and the outer peripheral side of the single battery, and the gap is filled with a fixing glue layer.

[0017] To implement the above technical solution, the single cell and the limiting protrusion are fixedly connected, and the limiting protrusion can not only provide a limiting effect perpendicular to the axis of the single cell to overcome the scouring force of the cooling medium; but also provide a limiting force in the axial direction of the single cell to further ensure the stability of the single cell when it vibrates along its own axis.

[0018] As one of the optional embodiments of the present application, a sealing groove is provided on the surface of the flow channel cover body facing away from the bottom wall, the sealing groove surrounds the circumference of the first through hole and is connected to the first through hole, and the sealing groove is filled with a sealant layer.

[0019] The above technical solution is implemented to provide a structure for sealing the single cell and the first through hole. The setting of the sealing groove makes the application of the sealing glue layer more uniform and convenient.

[0020] As one of the optional embodiments of the present application, the box body is provided with a liquid inlet and a liquid outlet connected to the cooling chamber, and a plurality of partitions are arranged inside the box body at intervals, and the partitions are respectively sealed and fixedly connected to the flow channel cover and the bottom wall, each of the partitions extends in a length direction parallel to the box body, and a cooling flow channel for the cooling medium to pass through is formed between two adjacent partitions.

[0021] To implement the above technical solution, the cooling channel divides the cooling cavity into a plurality of narrow channels, and connects the liquid inlet and the liquid outlet to allow the cooling medium to circulate, thereby improving the heat dissipation effect.

[0022] As one of the optional implementation schemes of the present application, the number of the liquid inlets is two, and they are arranged on opposite sides of the liquid outlet, the cooling channel includes two branch channels and one confluence channel, the two branch channels are located on opposite sides of the confluence channel, the liquid inlet end of each branch channel is connected to one of the liquid inlets, and the liquid outlet end is connected to the liquid inlet end of the confluence channel; the liquid outlet end of the confluence channel is connected to the liquid outlet, the flow path length of the coolant in the two branch channels differs by 0 to 10 cm, and the sum of the flow areas of the two liquid inlets is less than or equal to the flow area of ​​the liquid outlet.

[0023] To implement the above technical solution, the cooling medium flow paths in multiple branch channels are roughly the same, and the coolant introduced from multiple liquid inlets eventually flows out from the liquid outlet almost simultaneously. The cooling effects on the single cells located in different branch channels are basically consistent, so that the temperatures of the multiple single cells 4 tend to be consistent, improving the temperature uniformity performance, so as to ensure the overall charging and discharging performance of the battery pack.

[0024] As one of the optional implementation schemes of the present application, each branch channel includes N linear flow channel portions and N-1 reversing flow channel portions, each linear flow channel portion is extended along the length direction of the box body; the N linear flow channel portions are arranged along the direction from the liquid inlet to the liquid outlet, and the reversing flow channel portion is connected between two adjacent linear flow channel portions, N≥2.

[0025] As one of the optional embodiments of the present application, the partition includes a connecting portion and an extending portion, the connecting portion is fixedly connected to the side wall, one end of the connecting portion is fixedly connected to one of the side walls, and the other end is connected to the extending portion; the extending portion extends along the length direction toward the direction of the other side wall, and a gap is left between one end of the extending portion away from the connecting portion and the other side wall to form the reversing flow channel portion.

[0026] As one of the optional embodiments of the present application, the single cell is arranged to abut the bottom wall at one end face facing the bottom wall, an explosion-proof valve is provided at one end face of the single cell facing the bottom wall, a plurality of second through holes covering the explosion-proof valve area are opened on the bottom wall, and an end of the single cell close to the bottom wall is sealed between the second through holes.

[0027] As one of the optional implementation schemes of the present application, a pressure relief channel is provided in the box body, the pressure relief channel is connected to the area of ​​the second through hole, and a pressure relief hole connected to the pressure relief channel is provided on the box body.

[0028] By implementing the above technical solution, when thermal runaway occurs in the battery, the gas or liquid released by the single battery is discharged from the pressure relief channel to ensure the overall safety of the battery pack.

[0029] As one of the optional implementation schemes of the present application, a side of the bottom wall facing away from the box cover body is provided with a recessed groove, and the side of the bottom wall facing away from the box cover body is also covered and fixed with a bottom plate, and the bottom plate and the recessed groove together form the pressure relief channel.

[0030] One of the above technical solutions has the following advantages or beneficial effects:

[0031] 1. When the monomer adopts immersion cooling, the bottom of the monomer battery in the cooling chamber is limited by the limiting groove. When the monomer battery is subjected to the scouring force or vibration force of the cooling medium, it can maintain a relatively stable state. The limiting groove can give the monomer battery a limiting fixing force perpendicular to its own axis, reduce the shaking or shaking tendency of the monomer battery, and avoid the sealing structure between the monomer battery and the first through hole from being destroyed, so as to make the connection between the monomer battery and the box body more reliable.

[0032] 2. The bottom of the single cell is limited along the height direction of the battery pack by a fixed glue layer. When the battery pack is subjected to vibration along its own height direction, it can also provide fixing force to ensure the stability of the single cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The technical solution and other beneficial effects of the present application will be made apparent by describing in detail the specific implementation methods of the present application in conjunction with the accompanying drawings.

[0034] Figure 1 is an overall structural diagram of the battery pack provided in Example 1 of the present application;

[0035] Figure 2 is a cross-sectional view of a battery pack in an exploded state provided in Example 1 of the present application;

[0036] Figure 3 is an exploded structural diagram of a battery pack provided in Example 1 of the present application;

[0037] Figure 4 is a cross-sectional view of a battery pack provided in Example 1 of the present application;

[0038] Figure 5 This is provided in Example 1 of the present application Figure 2 A partial enlarged view of part A;

[0039] Figure 6 It is an overall stereogram provided in Example 1 of the present application and mainly used to show the cooling channel structure;

[0040] Figure 7 It is a top plan view provided in Example 1 of the present application and mainly used to show the cooling channel;

[0041] Figure 8 It is a top plan view mainly used to show the positions of the liquid inlet and the liquid outlet in another embodiment;

[0042] Fig. 9 It is a schematic diagram provided in Example 1 of the present application and mainly used to show the partition structure;

[0043] Fig.10 It is an exploded structure diagram provided in Example 1 of the present application, mainly used to show the pressure relief channel.

[0044] Reference numerals: 1, box assembly; 11, box body; 111, bottom wall; 1111, second through hole; 112, side wall; 113, accommodating cavity; 12, box cover; 1a, liquid inlet; 1b, liquid outlet; 13, mounting groove; 2, limiting protrusion; 21, limiting groove; 3, flow channel cover; 31, cooling cavity; 32, first through hole; 33, sealing groove; 331, sealing adhesive layer; 4, single battery; 4 1. Explosion-proof valve; 5. Stabilizing sleeve; 6. Gap; 7. Partition; 71. Connecting part; 72. Extending part; 721. Recessed space; 8. Cooling channel; 81. Branch channel; 811. Linear channel; 812. Reversing channel; 82. Converging channel; 9. Pressure relief channel; 91. Pressure relief hole; 911. Blocking screw; 9a. Recessed groove; 9b. Bottom plate; 101. Converging groove; 102. Exhaust channel. DETAILED DESCRIPTION

[0045] The technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present application.

[0046] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the term "and / or" in this article is only a description of the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article, unless otherwise specified, generally indicates that the associated objects before and after are in an "or" relationship.

[0047] The following is combined with Figure 1-10 The present application is further described.

[0048] Reference Figure 1 and Figure 2 This embodiment discloses a battery pack, which has a height direction. The battery pack includes a box assembly 1, a flow channel cover 3 and a single battery 4. The box assembly 1 includes a box body 11 and a box cover 12. Among them, the box body 11 includes a bottom wall 111 and a side wall 112 surrounding the periphery of the bottom wall 111. The bottom wall 111 and the side wall 112 cooperate to enclose a receiving cavity 113 with an open end. The box cover 12 covers the open opening along the height direction.

[0049] Reference Figure 2 and Figure 3 The flow channel cover 3 is disposed in the accommodating cavity 113, and the edge of the flow channel cover 3 is fixed on the side wall 112, which is fixed by welding in this embodiment. The flow channel cover 3 cooperates with the bottom wall 111 and the side wall 112 to enclose a cooling cavity 31, and a plurality of first through holes 32 are opened on the flow channel cover 3. The single cell 4 is passed through the first through hole 32 and at least part of the single cell 4 is located in the cooling cavity 31, thereby realizing immersion cooling of the single cell 4.

[0050] Reference Figure 4 and Figure 5 The bottom wall 111 is provided with a limiting groove 21 on one side facing the box cover 12, and the limiting groove 21 extends in the height direction. In this embodiment, the formation structure of the limiting groove 21 is as follows: a limiting protrusion 2 is provided on the surface of the bottom wall 111 facing the box cover 12, and the limiting protrusion 2 extends in the height direction. The limiting protrusion 2 and the bottom wall 111 are surrounded to form the limiting groove 21. The bottom of the single battery 4 is embedded in the limiting groove 21. In other optional embodiments, the limiting groove 21 can also be formed by directly concavely on the side of the bottom wall 111 facing the box cover 12.

[0051] The above setting makes the top of the single cell 4 and the first through hole 32 sealed and fixed when the single cell 4 is installed. In the present embodiment, the top of the single cell 4 and the first through hole 32 are welded. Specifically, it is low-frequency welding, which means providing an alternating current with a frequency below 12 Hz for resistance welding. The bottom of the single cell 4 located in the cooling chamber 31 is limited by the limiting groove 21. When the single cell 4 is subjected to the flushing force or vibration force of the cooling medium, it can maintain a relatively stable state to avoid the sealing structure between the single cell 4 and the first through hole 32 from being destroyed, so as to make the connection between the single cell 4 and the box body 11 more reliable. The single cell 4 is also limited by the first through hole 32 at the top, which further improves the stability of the single cell 4.

[0052] In this embodiment, the single cell 4 is cylindrical, and the shape of the limiting protrusion 2 is set to be a cylindrical sleeve and is sleeved on the circumferential outer side of the single cell 4. In other optional embodiments, the limiting protrusion 2 can be adaptively changed according to the shape of the single cell 4. For example, for a square single cell 4, the limiting protrusion 2 can be configured as a square sleeve. Of course, the limiting protrusion 2 is not limited to a sleeve shape, as long as it can provide a limiting force perpendicular to the height direction to the single cell 4. For example, for a cylindrical battery cell, the limiting protrusion 2 can also be set as a plurality of arc-shaped plates spaced around the limiting protrusion 2 in the circumferential direction. For example, for a square battery cell, the limiting protrusion 2 can be set to a baffle corresponding to each outer side of the single cell 4.

[0053] Reference Figure 5 The flow channel cover 3 is also integrally provided with a stabilizing sleeve 5 on one side facing the bottom wall 111. The stabilizing sleeve 5 extends in the height direction and is sleeved on the outer peripheral side of the single battery 4. The structure of the stabilizing sleeve 5 matches the shape setting of the single battery 4 and is not limited to the sleeve shape. The stabilizing sleeve 5 increases the contact area between the circumferential side surface of the single battery 4 near the top and the box body 11, so that the position of the single battery 4 is more stable.

[0054] Reference Figure 5 There is a gap 6 between the limiting protrusion 2 and the outer peripheral side of the single cell 4, and the gap 6 is filled with a fixed glue layer. In this embodiment, since the limiting protrusion 2 is sleeve-shaped, the fixed glue layer can simultaneously play the role of fixing and sealing. That is, the fixed glue layer seals the gap 6, and the cooling medium cannot invade the bottom of the single cell 4. The limiting protrusion 2 can not only provide a limiting effect perpendicular to the axial direction of the single cell 4 to overcome the scouring force of the cooling medium; it can also provide a limiting force in the axial direction of the single cell 4 to further ensure the stability of the single cell 4 when it vibrates along its own axial direction.

[0055] Reference Figure 5A sealing groove 33 is provided on the surface of the flow channel cover body 3 away from the bottom wall 111. The sealing groove 33 surrounds the circumference of the first through hole 32 and is connected to the first through hole 32. The sealing groove 33 is filled with a sealing glue layer 331. A structure for sealing the single cell 4 and the first through hole 32 is provided. The low-temperature welding between the single cell 4 and the first through hole 32 forms a first sealing fixing structure, and the setting of the sealing glue layer 331 forms a second sealing fixing structure. On the one hand, the sealing is ensured to prevent the cooling medium from overflowing. On the other hand, the stability of the connection between the single cell 4 and the box body 11 is further improved, and the shaking problem caused by the scouring of the cooling medium or the vibration working condition is reduced.

[0056] Reference Figure 2 , Figure 6 and Figure 7 The box body 11 is provided with a liquid inlet 1a and a liquid outlet 1b which are connected to the cooling chamber 31. The box body 11 has a length direction and a width direction, and the direction in which the cooling medium flows in the liquid inlet 1a and the liquid outlet 1b is in the same direction as the length direction. A plurality of partitions 7 are arranged at intervals in the box body 11, each of which extends in a length direction parallel to the box body 11, and a plurality of partitions 7 are arranged at intervals along the width direction of the box body 11. The top and bottom of the partition 7 are sealed and fixedly connected to the flow channel cover 3 and the bottom wall 111 respectively, and a cooling flow channel 8 for the cooling medium to pass through is formed between two adjacent partitions 7.

[0057] Reference Figure 6 and Figure 7 The number of liquid inlets 1a is two, and they are arranged on opposite sides of the liquid outlet 1b, specifically, the two liquid inlets 1a are arranged on opposite sides of the axial direction of the liquid outlet 1b. The cooling channel 8 includes two branch channels 81 and a confluence channel 82. The two branch channels 81 are located on opposite sides of the confluence channel 82. The liquid inlet end of each branch channel 81 is connected to a liquid inlet 1a, and the liquid outlet end is connected to the liquid inlet end of the confluence channel 82; the liquid outlet end of the confluence channel 82 is connected to the liquid outlet 1b, and the flow path length of the coolant in the two branch channels 81 differs by 0 to 10 cm.

[0058] The cooling medium flow paths in the multiple branch channels 81 are roughly the same. The coolant introduced from the multiple liquid inlets 1a eventually flows out from the liquid outlet 1b almost simultaneously. The cooling effects on the single cells 4 located in different branch channels 81 are basically consistent, so that the temperatures of the multiple single cells 4 tend to be consistent, improving the temperature uniformity performance, so as to ensure the overall charging and discharging performance of the battery pack.

[0059] It should be noted that, in other optional embodiments, the liquid inlet 1a and the liquid outlet 1b may not be located on the same side wall 112 of the box body 11. Figure 8, two liquid inlets 1a are located on a side wall 112 of the box body 11, and a liquid outlet 1b is opened on a side wall 112 of the box body 11 facing the liquid inlet 1a. It is only necessary to ensure that the flow paths of the cooling medium in the shunt channel 81 are close, such as 0 to 10 cm provided in this embodiment, so that the cooling effect of the single battery 4 in different shunt channels 81 can be consistent. The specific difference value is not limited to 0 to 10 cm, and needs to be determined comprehensively in combination with the composition of the cooling medium and the working performance of the single battery 4.

[0060] Reference Figure 7 Each flow channel 81 includes N linear flow channel portions 811 and N-1 reversing flow channel portions 812. Each linear flow channel 811 is extended along the length direction of the box body 11. The N linear flow channel portions 811 are arranged along the width direction of the box body 11 (i.e., the direction from the liquid inlet 1a to the liquid outlet 1b), and the reversing flow channel portion 812 is connected between two adjacent linear flow channel portions 811, and N≥2. In this embodiment, N is 3. The cooling medium bends and turns 180 degrees when passing through each reversing flow channel portion 812. This setting makes the flow channel 81 "S"-shaped, so that it contacts the single battery 4 in a larger range.

[0061] Reference Fig. 9 Each partition 7 includes a connecting portion 71 and an extending portion 72, and the connecting portion 71 and the extending portion 72 are integrally connected. In this embodiment, the connecting portion 71 is a flat plate, one end of the connecting portion 71 is fixedly connected to a side wall 112, and the other end is connected to the extending portion 72, and the extending portion 72 extends along the length direction in the direction where the other side wall 112 is located, and a gap is left between the end of the extending portion 72 away from the connecting portion 71 and the other side wall 112 to form a reversing flow channel portion 812. Among them, the projection of the extending portion 72 on the bottom wall 111 is a wave-shaped structure.

[0062] Reference Fig. 9, the extension part 72 is set to be wavy, so that a plurality of recessed spaces 721 are formed on one side of the extension part 72 facing the single battery 4, and each recessed space 721 is designed to be in the same shape as the outer wall of a single battery 4, that is, the recessed direction of the recessed space 721 is the same as the arc shape of the outer wall of the corresponding single battery 4. This setting is based on the following considerations: if the side of the extension part 72 is designed to be a plane, when the cooling medium flows in the cooling channel 8, the single battery 4 in the middle blocks the cooling medium, while the resistance on both sides is small, which will cause the cooling medium to flow fast on both sides and slow in the middle, thereby causing the flow rate of the cooling medium to be uneven. On the one hand, it causes different cooling effects at different positions of the single battery 4. For example, the outer peripheral side of the single battery 4 close to both sides has a good cooling effect because the cooling medium flows fast, and the heat is taken away in time, while the cooling effect at the middle position is not good enough. On the other hand, it also causes differences in the cooling effects of the single batteries 4 at different positions. In the design of the present solution, the cooling medium will encounter resistance when passing through each recessed space 721, so that the overall flow rate of the cooling medium in the cooling channel 8 tends to be consistent, thereby ensuring that the cooling effect of the single cell 4 is as consistent as possible, reducing the temperature difference between the single cells 4, and improving the temperature uniformity of multiple single cells 4, thereby ensuring the performance of the battery pack.

[0063] It should be noted that the adjacent lines of the wave shape at the turning point may also be straight lines, and the turning position may not be set as an arc transition, but may be set as, for example, point contact, straight line transition, etc. At this time, the concave space 721 may also have a certain resistance to improve the flow uniformity of the cooling medium.

[0064] Reference Figure 5 , one end face of the single cell 4 facing the bottom wall 111 is arranged against the bottom wall 111, an explosion-proof valve 41 is arranged on one end face of the single cell 4 facing the bottom wall 111, a plurality of second through holes 1111 covering the explosion-proof valve 41 area are opened on the bottom wall 111, and one end of the single cell 4 close to the bottom wall 111 is sealed with the second through hole 1111. In this embodiment, the sealing between the single cell 4 and the second through hole 1111 is achieved by filling the gap 6 with a fixed adhesive layer. In other optional embodiments, the side surface of the single cell 4 and the side surface of the sleeve-shaped limiting protrusion 2 can also be welded and sealed by low-temperature welding, or a glue layer can be applied on one side of the bottom wall 111 close to the single cell 4. When the single cell 4 is embedded in the limiting groove 21, the side of the single cell 4 close to the bottom wall 111 is bonded with the glue layer to complete the sealing.

[0065] Reference Figure 5 and Fig.10, a pressure relief channel 9 is provided on the bottom wall 111 of the box body 11, and the pressure relief channel 9 is correspondingly connected to the area of ​​the second through hole 1111, and a pressure relief hole 91 connected to the pressure relief channel 9 is provided on the box body 11. Its specific formation structure is: a recessed groove 9a is provided on the side of the bottom wall 111 away from the box cover body 12, and the recessed groove 9a is long and extends along the length direction of the box body 11. The side of the bottom wall 111 away from the box cover body 12 is also covered and fixed with a bottom plate 9b, and the bottom plate 9b is welded and fixed to the bottom wall 111, and the bottom plate 9b and the recessed groove 9a are surrounded to form a pressure relief channel 9. When the battery has thermal runaway, the gas or liquid released by the single battery 4 is discharged from the pressure relief channel 9 to ensure the overall safety of the battery pack.

[0066] Reference Figure 3 and Fig.10 , the top surface of the box body 11 in the height direction is also provided with an installation groove 13, and the installation groove 13 is used to install electrical components. The bottom wall 111 of the box body 11 is recessed and provided with a confluence groove 101, which is connected to multiple recessed grooves 9a at the same time, and the bottom wall 111 of the box body 11 is located at both ends of the length of the installation groove 13. The exhaust channel 102 is connected to the pressure relief channel 9 and the confluence groove 101. When the battery has thermal runaway, the gas is discharged from the pressure relief channel 9, the confluence groove 101, and the exhaust channel 102 to the outside of the battery pack through the pressure relief hole 91. The pressure relief hole 91 is also threaded with a plugging screw 911. When the pressure in the exhaust channel 102 reaches a certain value, the plugging screw 911 will be flushed open.

[0067] The above description is only a partial implementation method of the embodiments of the present application and does not constitute any form of limitation on the application. The protection scope of the embodiments of the present application is not limited thereto. Any simple modifications, equivalent changes and modifications that can be easily thought of by any technician familiar with the technical field within the technical scope disclosed in the embodiments of the present application should be covered within the protection scope of the embodiments of the present application.

Claims

1. A battery pack, the battery pack having a height direction, characterized in that: include: A box assembly (1) comprises a box body (11) and a box cover (12), wherein the box body (11) comprises a bottom wall (111) and a side wall (112) arranged around the periphery of the bottom wall (111), wherein the bottom wall (111) and the side wall (112) cooperate to enclose a receiving cavity (113) with an open end, wherein the box cover (12) covers the open end along the height direction, and a limiting groove (21) is arranged on a side of the bottom wall (111) facing the box cover (12), wherein the limiting groove (21) extends along the height direction; A flow channel cover body (3) is disposed in the accommodating cavity (113); the flow channel cover body (3) cooperates with the bottom wall (111) and the side wall (112) to enclose a cooling cavity (31); and the flow channel cover body (3) is provided with a first through hole (32); A single cell (4), wherein the single cell (4) is inserted into the first through hole (32) and at least a portion of the single cell (4) is located in the cooling cavity (31), and the bottom of the single cell (4) is embedded in the limiting groove (21).

2. The battery pack according to claim 1, characterized in that: A limiting protrusion (2) is provided on the surface of the bottom wall (111) facing the box cover body (12); the limiting protrusion (2) extends along the height direction; the limiting protrusion (2) and the bottom wall (111) are combined to form the limiting groove (21).

3. The battery pack according to claim 1 or 2, characterized in that: A stabilizing sleeve (5) is also provided on one side of the flow channel cover body (3) facing the bottom wall (111); the stabilizing sleeve (5) extends along the height direction; the stabilizing sleeve (5) is sleeved on the outer peripheral side of the single battery (4).

4. The battery pack according to claim 2, characterized in that: A gap (6) is provided between the limiting protrusion (2) and the outer peripheral side surface of the single battery (4), and the gap (6) is filled with a fixing glue layer.

5. The battery pack according to claim 1, wherein: A sealing groove (33) is provided on the surface of the flow channel cover body (3) facing away from the bottom wall (111), the sealing groove (33) surrounds the circumference of the first through hole (32) and is connected to the first through hole (32), and the sealing groove (33) is filled with a sealing rubber layer (331).

6. The battery pack according to claim 1, wherein: The box body (11) is provided with a liquid inlet (1a) and a liquid outlet (1b) which are connected to the cooling chamber (31); a plurality of partitions (7) are arranged at intervals inside the box body (11); the partitions (7) are respectively sealed and fixedly connected to the flow channel cover (3) and the bottom wall (111); each of the partitions (7) extends in a length direction parallel to the box body (11); and a cooling flow channel (8) for cooling medium to pass through is formed between two adjacent partitions (7).

7. The battery pack according to claim 6, characterized in that: The number of the liquid inlets (1a) is two and they are arranged on two opposite sides of the liquid outlet (1b); the cooling flow channel (8) comprises two branch channels (81) and one converging channel (82); the two branch channels (81) are located on two opposite sides of the converging channel (82); the liquid inlet end of each branch channel (81) is connected to one of the liquid inlets (1a), and the liquid outlet end is connected to the liquid inlet end of the converging channel (82); The liquid outlet end of the converging channel (82) is connected to the liquid outlet (1b), the flow path lengths of the coolant in the two branching channels (81) differ by 0 to 10 cm, and the sum of the flow areas of the two liquid inlets (1a) is less than or equal to the flow area of ​​the liquid outlet (1b).

8. The battery pack according to claim 7, characterized in that: Each branch flow channel (81) includes N linear flow channel portions (811) and N-1 reversing flow channel portions (812); Each linear flow channel portion (811) is extended along the length direction of the box body (11); N linear flow channel portions (811) are arranged along the direction from the liquid inlet (1a) to the liquid outlet (1b), and the reversing flow channel portion (812) is connected between two adjacent linear flow channel portions (811), and N≥2.

9. The battery pack according to claim 8, characterized in that: The partition (7) comprises a connecting portion (71) and an extending portion (72); one end of the connecting portion (71) is fixedly connected to one of the side walls (112), and the other end is connected to the extending portion (72); the extending portion (72) extends along the length direction in the direction where the other side wall (112) is located, and a gap is left between one end of the extending portion (72) away from the connecting portion (71) and the other side wall (112) to form the reversing flow channel portion (812).

10. The battery pack according to claim 1, wherein: One end face of the single cell (4) facing the bottom wall (111) is arranged against the bottom wall (111); one end face of the single cell (4) facing the bottom wall (111) is provided with an explosion-proof valve (41); a plurality of second through holes (1111) covering the area of ​​the explosion-proof valve (41) are provided on the bottom wall (111); and one end of the single cell (4) close to the bottom wall (111) is sealed from the second through hole (1111).

11. The battery pack according to claim 10, characterized in that: A pressure relief channel (9) is provided in the box body (11), and the pressure relief channel (9) is connected to a region corresponding to the second through hole (1111); and a pressure relief hole (91) connected to the pressure relief channel (9) is provided on the box body (11).

12. The battery pack according to claim 11, characterized in that: A concave groove (9a) is provided on one side of the bottom wall (111) facing away from the box cover body (12), and a bottom plate (9b) is also covered and fixed on the other side of the bottom wall (111) facing away from the box cover body (12), and the bottom plate (9b) and the concave groove (9a) together form the pressure relief channel (9).

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