Battery pack

Abstract

The invention provides a battery pack which comprises a battery box, a battery cell assembly and a CCS assembly, the battery box comprises a box body and a box cover which are distributed in the height direction of the battery pack, and a cavity is defined by the box body and the box cover; the battery cell assembly is arranged in the cavity and comprises a plurality of battery cells, and pressure relief holes are formed in the end faces, facing the box cover, of the battery cells; the CCS assembly is arranged on the side, facing the box cover, of the battery cell assembly, the CCS assembly comprises a busbar connected with the multiple battery cells and a support used for installing the busbar, a pressure relief channel is formed between the support and the box cover, a through hole is formed in the position, corresponding to at least one pressure relief hole, of the support, and the through hole penetrates through the support in the height direction. According to the battery pack provided by the embodiment of the invention, the pressure relief channel is formed between the bracket of the CCS assembly and the box cover, so that the rapid pressure relief of the battery cell can be realized, the structure of the pressure relief channel is relatively simple, excessive space in the battery pack cannot be occupied, and the space utilization rate of the battery pack can be improved.

Description

Technical Field

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

[0002] The battery pack's cells are equipped with pressure relief holes. When the air pressure inside the cells exceeds a preset pressure, the pressure relief valve located in the pressure relief hole will open, allowing the gas in the cells to be discharged through the pressure relief hole into the pressure relief channel of the battery pack.

[0003] However, in the related art, the design of the pressure relief channel in the battery pack is relatively complex, which will occupy too much space in the battery pack, resulting in low space utilization of the battery pack. Summary of the Invention

[0004] An embodiment of the present application provides a battery pack that can improve the technical problem that the design of the pressure relief channel in the battery pack is relatively complex, which occupies more space in the battery pack and leads to low space utilization of the battery pack.

[0005] In a first aspect, an embodiment of the present application provides a battery pack, comprising:

[0006] The battery box includes a box body and a box cover distributed along the height direction of the battery pack, wherein the box body and the box cover enclose a cavity;

[0007] A battery cell assembly is disposed in the cavity, the battery cell assembly includes a plurality of battery cells, and a pressure relief hole is provided on the end surface of the battery cell facing the box cover;

[0008] A CCS assembly is provided on a side of the battery cell assembly facing the box cover. The CCS assembly includes a busbar connected to the multiple battery cells and a bracket for mounting the busbar. A pressure relief channel is formed between the bracket and the box cover. The bracket is provided with a through hole at a position corresponding to at least one of the pressure relief holes. The through hole penetrates the bracket along the height direction.

[0009] In one embodiment, on a projection plane perpendicular to the height direction, the orthographic projection of the through hole covers the orthographic projection of the corresponding pressure relief hole.

[0010] In one embodiment, the through hole is an arc-shaped hole extending circumferentially along the central axis of the corresponding battery cell.

[0011] In one embodiment, the angle of the arc-shaped hole is greater than or equal to 20° and less than or equal to 40°.

[0012] In one embodiment, in the direction from the central axis to the arc-shaped hole, the width of the arc-shaped hole is greater than the outer diameter of the pressure relief hole, and the difference between the width of the arc-shaped hole and the outer diameter of the pressure relief hole is greater than or equal to 1 mm.

[0013] In one embodiment, the battery pack further includes an insulating layer, which is disposed on a side of the CCS assembly facing away from the battery cell assembly, and the insulating layer covers at least a portion of the busbar.

[0014] In one embodiment, the insulating layer is bonded to at least a portion of the busbar.

[0015] In one embodiment, the bonding strength between the insulating layer and the busbar is greater than or equal to 9 N / cm.

[0016] In one embodiment, the area of the busbar used for bonding with the insulating layer is S1, and the total area of the surface of the busbar facing away from the battery cell assembly is S, wherein S1 / S≥0.85.

[0017] In one embodiment, the insulating layer further covers at least a portion of the through hole.

[0018] In one embodiment, the insulating layer is bonded to at least a portion of the bracket.

[0019] In one embodiment, a protrusion is provided on a side of the bracket facing away from the battery cell assembly, and the through hole passes through the protrusion.

[0020] In one embodiment, the insulating layer is bonded to a surface of the protrusion away from the battery cell assembly and covers the through hole.

[0021] In one embodiment, the insulating layer is bonded to at least a portion of the busbar, and the bonding force between the insulating layer and the busbar is greater than or equal to 9 N / cm; and / or,

[0022] The insulating layer is bonded to at least a portion of the bracket, and the bonding force between the insulating layer and the bracket is greater than or equal to 9 N / cm.

[0023] In one embodiment, the insulating layer is bonded to at least a portion of the bus and at least a portion of the bracket, a height of a surface of the bus for bonding to the insulating layer relative to the end face is H1, and a height of a surface of the bracket for bonding to the insulating layer relative to the end face is H2, wherein |H1-H2|≤5mm.

[0024] In one embodiment, the height of the surface of the busbar for bonding with the insulating layer relative to the end face is H1, and the height of the surface of the bracket for bonding with the insulating layer relative to the end face is H2, wherein H1≤H2.

[0025] In one embodiment, the insulating layer comprises mica paper.

[0026] Beneficial effects of the embodiments of the present application:

[0027] The battery pack provided in the embodiments of the present application comprises a cell assembly disposed within a cavity formed by the body and lid of a battery box. Pressure relief holes are provided on the end faces of the cells of the battery assembly facing the lid. A through-hole extending along the height of the battery pack is provided at a position corresponding to at least one of the pressure relief holes in the CCS assembly bracket, and a pressure relief channel is formed between the CCS assembly bracket and the lid. When the air pressure within the cell exceeds a preset pressure, causing the pressure relief hole to open, gases, electrolytes, etc. within the cell can be discharged from the pressure relief hole and discharged through the through-holes in the bracket into the pressure relief channel between the bracket and the lid, thereby achieving rapid pressure relief for the cell.

[0028] Moreover, a pressure relief channel can be formed between the bracket and the box cover by simply setting the bracket and the box cover at a distance. The structure of the pressure relief channel is relatively simple and will not occupy too much space in the battery pack, which can improve the space utilization of the battery pack. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0030] Figure 1 A cross-sectional view of an embodiment of a battery pack provided in an embodiment of the present application, wherein the cross-sectional view is parallel to the height direction of the battery pack;

[0031] Figure 2 for Figure 1 Enlarged view of point A in the middle;

[0032] Figure 3 A schematic diagram of the exploded structure of a battery pack according to an embodiment of the present application;

[0033] Figure 4 for Figure 3 Enlarged view of point B in the middle;

[0034] Figure 5 A top view of the bracket and battery cell assembly provided in an embodiment of the present application;

[0035] Figure 6 for Figure 5 Enlarged view of point C in the middle.

[0036] Battery pack 1; battery cell assembly 10; battery cell 11; end face 111; pole 112; pressure relief hole 113; pressure relief valve 114; CCS assembly 20; busbar 21; connector 211; output bus 212; bracket 22; through hole 221; protrusion 222; battery box 30; box body 31; box cover 32; cavity 33; pressure relief channel 34; insulation layer 40. DETAILED DESCRIPTION

[0037] The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without making creative work are within the scope of protection of the present application. In addition, it should be understood that the specific implementation methods 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, unless otherwise specified, the directional words used, such as "upper" and "lower", generally refer to the upper and lower parts of the device in actual use or working state, specifically the drawing direction in the accompanying drawings; and "inside" and "outside" refer to the outline of the device.

[0038] The present application provides a battery pack. Each embodiment of the battery pack is described in detail below.

[0039] Figure 1 This is a cross-sectional view of an embodiment of a battery pack provided in an embodiment of the present application, wherein the cross-sectional view is parallel to the height direction of the battery pack. Figure 2 for Figure 1 The enlarged view of point A in the middle. Figure 1 and Figure 2 As shown, the battery pack 1 includes a cell assembly 10, which includes a plurality of cell 11. The cell 11 is provided with a pressure relief hole 113 on an end face 111 at one end of the height direction Z of the battery pack 1. When the air pressure in the cell 11 exceeds the preset air pressure, the pressure relief hole 113 will be opened to allow the gas in the cell 11 to be discharged through the pressure relief hole 113, thereby achieving rapid pressure relief of the cell 11. A pressure relief valve 114 can be provided at the pressure relief hole 113, which covers the pressure relief hole 113. When the air pressure in the cell 11 exceeds the preset air pressure, the pressure relief valve 114 opens, thereby opening the pressure relief hole 113.

[0040] Of course, a thinning groove can also be directly provided in the cover plate at one end of the battery cell 11 along the height direction Z of the battery pack 1 to form a closed pressure relief hole 113. When the air pressure in the battery cell 11 exceeds the preset pressure, the high-pressure gas will cause the cover plate to break at the thinning groove, thereby opening the pressure relief hole 113.

[0041] Continue to refer to Figure 1 and Figure 2The battery pack 1 further includes a CCS (Cells Contact System) assembly, wherein the CCS assembly 20 includes a busbar 21 for connecting to the multiple cells 11 of the cell assembly 10. The multiple cells 11 of the cell assembly 10 can be connected in series and in parallel via the busbar 21.

[0042] The battery cell 11 includes a pole 112 protruding from the end face 111. The pole 112 is insulated from the end face 111, and the polarity of the pole 112 is opposite to the polarity of the end face 111. The pole 112 can be a negative pole and the end face 111 can be a positive pole, or the pole 112 can be a positive pole and the end face 111 can be a negative pole.

[0043] The busbar 21 includes a plurality of connectors 211. The pole 112 of one of the two battery cells 11 is connected to the end face 111 of the other battery cell 11 via the connectors 211, thereby connecting the two battery cells 11 in series. Of course, the poles 112 of the two battery cells 11 can also be connected via the connectors 211 to connect the two battery cells 11 in series; or the end faces 111 of the two battery cells 11 can be connected via the connectors 211 to connect the two battery cells 11 in series.

[0044] Specifically, the battery cell assembly 10 includes multiple rows of battery cells 11. In the same row of battery cells 11, the pole 112 of one of two adjacent battery cells 11 is connected to the end face 111 of the other battery cell 11 via a connector 211, so that the battery cells 11 in the same row are connected in series. The connectors 211 connected to different rows of battery cells 11 can be connected via an output bus 212, so that multiple battery cells 11 are connected in parallel.

[0045] The pressure relief hole 113 of the battery cell 11 may be located at an end of the battery cell 11 close to the bus bar 21 , or may be located at an end of the battery cell 11 away from the bus bar 21 .

[0046] like Figure 2 and Figure 3 As shown, the battery pack 1 may further include a bracket 22, which is located on the side of the battery cell 11 where the pressure relief hole 113 is provided. The bracket 22 may be a component of the CCS assembly 20 and is used to mount the busbar 21 of the CCS assembly 20. The bracket 22 is located at one end of the battery cell 11 near the busbar 21, facilitating mounting of the busbar 21 thereon.

[0047] Of course, the bracket 22 can also be a structure for mounting the battery cell 11 or other components within the battery pack 1. The bracket 22 can be located on the side of the battery cell 11 close to the bus bar 21 or on the side of the battery cell 11 away from the bus bar 21, depending on the location of the pressure relief hole 113 of the battery cell 11.

[0048] In some embodiments, a through hole 221 may be provided at a position on the bracket 22 corresponding to at least one pressure relief hole 113, and the through hole 221 extends through the bracket 22 along the height direction Z of the battery pack 1. The through hole 221 corresponds to the position of the pressure relief hole 113. Specifically, on a projection plane perpendicular to the height direction Z, the orthographic projection of the through hole 221 at least partially overlaps with the orthographic projection of the corresponding pressure relief hole 113. Thus, when the pressure relief hole 113 of the battery cell 11 is opened, the gas, electrolyte, etc. within the battery cell 11 can pass through the through hole 221 and be discharged into the pressure relief channel 34 on the side of the bracket 22 facing away from the battery cell 11, and the pressure relief of the battery cell 11 will not be blocked by the bracket 22.

[0049] It should be noted that the bracket 22 can be provided with a through hole 221 at the position corresponding to the pressure relief hole 113 of one battery cell 11, or the bracket 22 can be provided with through holes 221 at the positions corresponding to the pressure relief holes 113 of multiple or all battery cells 11. Of course, the latter allows more battery cells 11 to be pressure-relieved through the through holes 221 of the bracket 22, thereby improving the safety of the battery pack 1.

[0050] In some embodiments, the battery pack 1 may further include a battery box 30, which includes a box body 31 and a box cover 32 arranged along the height direction Z of the battery pack 1. The box body 31 and the box cover 32 enclose a cavity 33. The battery cell assembly 10 is disposed within the cavity 33, and the end surface 111 of the battery cell 11 of the battery cell assembly 10 facing the box cover 32 is provided with a pressure relief hole 113. A pressure relief channel 34 is formed between the bracket 22 of the CCS assembly 20 and the box cover 32.

[0051] The battery pack 1 provided in the embodiment of the present application is configured such that the cell assembly 10 is disposed within a cavity 33 formed by the body 31 and cover 32 of the battery box 30. A pressure relief hole 113 is provided on the end face 111 of the cell 11 of the battery assembly facing the cover 32 of the battery box 30. A through hole 221 is provided on the bracket 22 of the CCS assembly 20 at a position corresponding to at least one pressure relief hole 113, extending along the height direction Z of the battery pack 1. A pressure relief channel 34 is formed between the bracket 22 of the CCS assembly 20 and the cover 32. When the air pressure within the cell 11 exceeds a preset pressure, causing the pressure relief hole 113 to be opened, the gas, electrolyte, etc. within the cell 11 can be discharged from the pressure relief hole 113 and discharged through the through hole 221 of the bracket 22 to the pressure relief channel 34 between the bracket 22 and the cover 32, thereby achieving rapid pressure relief for the cell 11.

[0052] Moreover, by simply setting the CCS bracket 22 and the box cover 32 at a distance, a pressure relief channel 34 can be formed between the bracket 22 and the box cover 32. The structure of the pressure relief channel 34 is relatively simple and does not occupy too much space in the battery pack 1, which can improve the space utilization of the battery pack 1.

[0053] In some embodiments, an exhaust hole (not shown in the figure) connected to the pressure relief channel 34 can be provided in the box body 31 or the box cover 32, so that the gas, electrolyte, etc. entering the pressure relief channel 34 can be discharged out of the battery box 30 through the exhaust hole.

[0054] In some embodiments, on a projection plane perpendicular to the height direction Z of the battery pack 1, the orthographic projection of the through-hole 221 of the bracket 22 can overlap the orthographic projection of the pressure relief hole 113 of the corresponding battery cell 11. As a result, the edge of the through-hole 221 does not obstruct the gas, electrolyte, etc. discharged from the corresponding pressure relief hole 113, allowing the gas, electrolyte, etc. discharged from the pressure relief hole 113 to pass more smoothly through the through-hole 221 of the bracket 22 and enter the pressure relief channel 34 between the bracket 22 and the box cover 32, thereby improving the safety and pressure relief efficiency of the battery pack 1.

[0055] Specifically, the orthographic projection of the through hole 221 of the bracket 22 on a projection plane perpendicular to the height direction Z of the battery pack 1 can be made to coincide with the orthographic projection of the pressure relief hole 113 of the corresponding battery cell 11 on a projection plane perpendicular to the height direction Z of the battery pack 1. Alternatively, the orthographic projection area of the through hole 221 of the bracket 22 on a projection plane perpendicular to the height direction Z of the battery pack 1 can be made larger than the orthographic projection area of the pressure relief hole 113 of the corresponding battery cell 11 on a projection plane perpendicular to the height direction Z of the battery pack 1. Of course, the latter option can further reduce the obstruction caused by the edge of the through hole 221 to the discharge of gas, electrolyte, etc. from the corresponding pressure relief hole 113, thereby facilitating smoother pressure relief of the battery cell 11.

[0056] In some embodiments, as Figures 4 to 6 As shown, the through hole 221 of the bracket 22 can be an arc-shaped hole extending circumferentially along the central axis X of the corresponding battery cell 11, thereby reducing the assembly accuracy requirements for the battery cell 11 and the bracket 22, which is beneficial to reducing the production cost of the battery pack 1 and improving the production efficiency of the battery pack 1.

[0057] It is understandable that during the assembly of the battery cells 11 and the bracket 22 of the battery pack 1 by machine or manual means, the multiple battery cells 11 rotate at different angles relative to the central axis X. Therefore, there may be a certain assembly error in the assembly angle of the battery cells 11 relative to the bracket 22.

[0058] By making the through hole 221 of the bracket 22 an arc-shaped hole extending circumferentially along the central axis X of the corresponding battery cell 11, even if there is a certain assembly error between the battery cell 11 and the bracket 22 during the assembly process, the orthographic projection of the through hole 221 of the bracket 22 on the projection plane perpendicular to the height direction Z of the battery pack 1 can still cover the orthographic projection of the pressure relief hole 113 of the corresponding battery cell 11 on the projection plane perpendicular to the height direction Z of the battery pack 1, or, the orthographic projection of the through hole 221 of the bracket 22 on the projection plane perpendicular to the height direction Z of the battery pack 1 and the orthographic projection of the pressure relief hole 113 of the corresponding battery cell 11 on the projection plane perpendicular to the height direction Z of the battery pack 1 have a large overlapping area, so that the gas, electrolyte, etc. discharged from the pressure relief hole 113 can pass through the through hole 221 of the bracket 22 more smoothly and enter the pressure relief channel 34 between the bracket 22 and the box cover 32.

[0059] Therefore, the assembly accuracy requirements for the bracket 22 and the battery cell 11 are relatively low, and there is no need to assemble the battery cell 11 and the bracket 22 through complex machines, or there is no need to manually calibrate the assembly angle of the battery cell 11, which is beneficial to reducing the production cost of the battery pack 1 and improving the production efficiency of the battery pack 1.

[0060] The central axis X of the battery cell 11 extends along the height direction Z of the battery pack 1 .

[0061] In some embodiments, the center of the arc-shaped through hole 221 can be located on the central axis X of the battery cell 11, so that when the battery cell 11 rotates around the central axis X relative to the bracket 22, there will be no large misalignment between the through hole 221 of the bracket 22 and the pressure relief hole 113 of the battery cell 11 in the width direction of the through hole 221.

[0062] Specifically, the arc-shaped hole extends along an arc segment S. The center of the arc segment S is located on the central axis X of the battery cell 11 .

[0063] In some embodiments, the angle of the arc-shaped hole can be greater than or equal to 20° and less than or equal to 40°. This can minimize the assembly precision requirements for the battery cell 11 and the bracket 22 while preventing the arc-shaped hole from being too large and affecting the strength of the bracket 22. The angle of the arc-shaped hole can be 21°, 25°, 28°, 30°, 37°, etc.

[0064] Specifically, the arc hole extends along the arc segment S and extends to both ends of the arc segment S. The angle of the arc hole is the angle α formed by the center of the arc segment S and the line connecting the two ends of the arc segment S, where 20°≤α≤40°.

[0065] In some embodiments, as Figure 2As shown, in the direction from the central axis X to the arc-shaped hole, the width W of the arc-shaped hole is greater than the outer diameter D of the pressure relief hole 113, and the difference between the width W of the arc-shaped hole and the outer diameter D of the pressure relief hole 113 is greater than or equal to 1 mm. As a result, during the assembly process of the battery cell 11, a certain amount of displacement of the battery cell 11 in the width direction of the arc-shaped hole is allowed, reducing the assembly accuracy requirements of the battery cell 11. The difference between the width W of the arc-shaped hole and the outer diameter D of the pressure relief hole 113 can be 1.1 mm, 1.3 mm, 1.5 mm, 2 mm, etc.

[0066] In some embodiments, as Figure 2 and Figure 3 As shown, the battery pack 1 further includes an insulating layer 40, which is provided on the side of the CCS assembly 20 facing away from the cell assembly 10, and the insulating layer 40 covers at least a portion of the busbar 21. As a result, the pressure relief channel 34 is located between the box cover 32 and the insulating layer 40. The insulating layer 40 can protect at least a portion of the busbar 21, reducing the risk of gas, electrolyte, or metal particles, etc., in the cell 11 being discharged into the pressure relief channel 34 between the bracket 22 and the box cover 32 through the pressure relief holes 113 of the cell 11 and the through holes 221 of the bracket 22. After the gas, electrolyte, or metal particles come into contact with the busbar 21 and the cell 11, the risk of secondary short circuit of the cell 11 and further thermal runaway is reduced.

[0067] It should be noted that the insulating layer 40 may cover a portion of the busbars 21 or may cover all of the busbars 21 . Of course, the latter can further reduce the risk of secondary thermal runaway of the battery cell 11 .

[0068] Specifically, the insulating layer 40 may cover the surfaces of the multiple connectors 211 and the output bar 212 of the busbar 21 facing away from the battery cell assembly 10 , so as to minimize the risk of secondary thermal runaway of the battery cell 11 .

[0069] In some embodiments, the insulating layer 40 may be bonded to at least a portion of the busbar 21 to improve the connection strength between the insulating layer 40 and the busbar 21 , thereby improving the insulation isolation effect of the insulating layer 40 on at least a portion of the busbar 21 .

[0070] Specifically, the insulating layer 40 can be bonded to at least a portion of the busbar 21 using double-sided tape. Of course, glue can also be applied to the surface of the insulating layer 40 facing the busbar 21 or to the surface of at least a portion of the busbar 21 facing the insulating layer 40, so that the insulating layer 40 and at least a portion of the busbar 21 are bonded together using glue.

[0071] In some embodiments, the area of the busbar 21 used for bonding with the insulating layer 40 is S1, and the total area of the surface of the busbar 21 facing away from the battery cell assembly 10 is S, wherein S1 / S can be ≥ 0.85. This can maximize the area of the busbar 21 used for bonding with the insulating layer 40, which is beneficial for improving the bonding strength between the busbar 21 and the insulating layer 40.

[0072] The ratio of the area S1 of the busbar 21 for bonding with the insulating layer 40 to the total area S of the surface of the busbar 21 facing away from the battery cell assembly 10 can be 0.86, 0.88, 0.9, 0.95, 1, etc.

[0073] In some embodiments, the bonding strength between the insulating layer 40 and the busbar 21 can be greater than or equal to 9 N / cm to maximize the bonding strength between the insulating layer 40 and the busbar 21. The bonding strength between the insulating layer 40 and the busbar 21 can be 10 N / cm, 12 N / cm, 15 N / cm, 20 N / cm, and the like.

[0074] In some embodiments, as Figure 2 As shown, the insulating layer 40 also covers at least a portion of the through-holes 221. When the air pressure within the battery cell 11 exceeds the preset pressure, causing the pressure relief hole 113 to open, the gas, electrolyte, etc. within the battery cell 11 can be discharged from the pressure relief hole 113 into the through-hole 221 of the bracket 22, breaking through the insulating layer 40 and entering the pressure relief channel 34. By having the insulating layer 40 cover at least a portion of the through-holes 221, the risk of conductive materials such as electrolyte and metal particles ejected from the through-holes 221 flowing into the gap between the insulating layer 40 and the bracket 22 and contacting the busbar 21 and the battery cell 11, thereby causing a secondary short circuit, can be reduced.

[0075] It should be noted that the insulating layer 40 may cover a portion of the through holes 221 or may cover all of the through holes 221. Of course, the latter can further reduce the risk of secondary short circuits, making the battery pack 1 safer.

[0076] In some embodiments, the insulating layer 40 can be bonded to at least a portion of the bracket 22 to further improve the installation stability of the insulating layer 40, so that the insulating layer 40 can more stably insulate the busbar 21. Moreover, when the insulating layer 40 covers at least a portion of the through hole 221, the insulating layer 40 can more stably cover the through hole 221.

[0077] The insulating layer 40 can be bonded to the bracket 22 by double-sided tape. Of course, glue can also be applied to the surface of the insulating layer 40 facing the busbar 21 or the surface of the bracket 22 facing the insulating layer 40 so that the insulating layer 40 and the bracket 22 are bonded by glue.

[0078] In some embodiments, as Figure 4 and Figure 6 As shown, a protrusion 222 is provided on the side of the bracket 22 facing away from the battery cell assembly 10, and the through hole 221 passes through the protrusion 222. As a result, the depth of the through hole 221 in the thickness direction Z can be extended by the protrusion 222, which is conducive to the communication between the through hole 221 and the pressure relief channel 34 on the side of the bracket 22 facing away from the battery cell 11.

[0079] The insulating layer 40 can be bonded to the surface of the protrusion 222 at one end away from the battery cell assembly 10 and cover the through-hole 221. As a result, the insulating layer 40 and the edge of the through-hole 221 have a high bonding strength. When the gas, electrolyte, and metal particles ejected from the through-hole 221 break through the insulating layer 40, the insulating layer 40 and the edge of the through-hole 221 remain sealed, which can prevent the electrolyte, metal particles, or other conductive materials from entering the gap between the edge of the through-hole 221 and the insulating layer 40 and contacting the busbar 21 or the battery cell 11, thereby causing a secondary short circuit.

[0080] In some embodiments, the bonding strength between the insulating layer 40 and the bracket 22 can be greater than or equal to 9 N / cm to maximize the bonding strength between the insulating layer 40 and the bracket 22. The bonding strength between the insulating layer 40 and the bracket 22 can be 10 N / cm, 12 N / cm, 15 N / cm, 20 N / cm, and the like.

[0081] It should be noted that the bonding strength between the insulating layer 40 and the busbar 21 and the bracket 22 can be greater than or equal to 9 N / cm, or only the bonding strength between the insulating layer 40 and the busbar 21 can be greater than or equal to 9 N / cm, or only the bonding strength between the insulating layer 40 and the bracket 22 can be greater than or equal to 9 N / cm.

[0082] In some embodiments, the insulating layer 40 can be bonded to at least a portion of the busbar 21 and at least a portion of the bracket 22. The height of the busbar 21 surface bonded to the insulating layer 40 relative to the end surface 111 is H1. The height of the bracket 22 surface bonded to the insulating layer 40 relative to the end surface 111 is H2. Here, |H1-H2|≤5mm.

[0083] By ensuring that the absolute value of the difference between H1 and H2 is less than or equal to 5 mm, it is possible to prevent a significant height difference between the surface of busbar 21 bonded to insulation layer 40 and the surface of bracket 22 bonded to insulation layer 40, which could result in the insulation layer 40 being unable to be stably bonded to both bracket 22 and busbar 21. The absolute value of the difference between H1 and H2 can be 0 mm, 1 mm, 3 mm, etc., as long as the insulation layer 40 is stably bonded to both busbar 21 and bracket 22.

[0084] In which, the height H1 of the surface of the busbar 21 used for bonding to the insulating layer 40 relative to the end face 111 can be less than the height H2 of the surface of the bracket 22 used for bonding to the insulating layer 40 relative to the end face 111, or it can be greater than or equal to the height H2 of the surface of the bracket 22 used for bonding to the insulating layer 40 relative to the end face 111.

[0085] In some embodiments, the height of the surface of the busbar 21 for bonding to the insulating layer 40 relative to the end face 111 is H1. The height of the surface of the bracket 22 for bonding to the insulating layer 40 relative to the end face 111 is H2. Among them, H1 can be made ≤ H2. As a result, the surface of the bracket 22 for bonding to the insulating layer 40 exceeds the surface of the busbar 21 for bonding to the insulating layer 40, which can prioritize the stable bonding between the insulating layer 40 and the bracket 22, and is conducive to reducing the problem of secondary short circuit caused by the gas, electrolyte, and metal particles ejected from the through hole 221 breaking through the insulating layer 40, and the electrolyte, metal particles or other conductive materials entering the gap between the edge of the through hole 221 and the insulating layer 40 and contacting the busbar 21 or the battery cell 11.

[0086] In some embodiments, the insulating layer 40 can include mica paper. This provides excellent insulation and high-temperature combustion resistance, effectively insulating and isolating the busbar 21 from the battery cell 11. Furthermore, the gas, electrolyte, and metal particles ejected from the through-holes 221 can smoothly penetrate the insulating layer 40 and enter the pressure relief channel 34.

[0087] The above is a detailed introduction to the embodiments of the present application. Specific examples are used herein to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the method and core idea of the present application. At the same time, for those skilled in the art, based on the ideas of the present application, there may be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as a limitation on the present application.

Claims

1. A battery pack, characterized in that: include: A battery box, comprising a box body and a box cover distributed along the height direction of the battery pack, wherein the box body and the box cover enclose a cavity; A battery cell assembly is disposed in the cavity, the battery cell assembly includes a plurality of battery cells, and a pressure relief hole is provided on the end surface of the battery cell facing the box cover; A CCS assembly is provided on a side of the battery cell assembly facing the box cover. The CCS assembly includes a busbar connected to the multiple battery cells and a bracket for mounting the busbar. A pressure relief channel is formed between the bracket and the box cover. The bracket is provided with a through hole at a position corresponding to at least one of the pressure relief holes. The through hole penetrates the bracket along the height direction.

2. The battery pack according to claim 1, wherein: On a projection plane perpendicular to the height direction, the orthographic projection of the through hole covers the orthographic projection of the corresponding pressure relief hole.

3. The battery pack according to claim 2, wherein: The through hole is an arc-shaped hole extending circumferentially along the central axis of the corresponding battery cell.

4. The battery pack according to claim 3, wherein: The angle of the arc-shaped hole is greater than or equal to 20° and less than or equal to 40°.

5. The battery pack according to claim 3, wherein: In the direction from the central axis to the arc-shaped hole, the width of the arc-shaped hole is greater than the outer diameter of the pressure relief hole, and the difference between the width of the arc-shaped hole and the outer diameter of the pressure relief hole is greater than or equal to 1 mm.

6. The battery pack according to any one of claims 1 to 5, wherein: The battery pack further includes an insulating layer, which is disposed on a side of the CCS assembly facing away from the battery cell assembly, and covers at least a portion of the busbar.

7. The battery pack according to claim 6, wherein: The insulating layer is bonded to at least a portion of the busbar.

8. The battery pack according to claim 7, wherein: The bonding force between the insulating layer and the busbar is greater than or equal to 9 N / cm.

9. The battery pack according to claim 7, wherein: The area of the busbar used for bonding with the insulating layer is S1, and the total area of the surface of the busbar facing away from the battery core assembly is S, wherein S1 / S≥0.

85.

10. The battery pack according to claim 6, wherein: The insulating layer also covers at least a portion of the through hole.

11. The battery pack according to claim 6, wherein: The insulating layer is bonded to at least a portion of the bracket.

12. The battery pack according to claim 11, wherein: A protrusion is provided on a side of the bracket facing away from the battery core assembly, and the through hole passes through the protrusion.

13. The battery pack according to claim 12, wherein: The insulating layer is bonded to a surface of the protrusion away from the battery core assembly and covers the through hole.

14. The battery pack according to claim 10, wherein: The bonding strength between the insulating layer and the bracket is greater than or equal to 9 N / cm.

15. The battery pack according to claim 6, wherein: The insulating layer is bonded to at least part of the bus and at least part of the bracket, the height of the surface of the bus for bonding to the insulating layer relative to the end face is H1, and the height of the surface of the bracket for bonding to the insulating layer relative to the end face is H2, wherein |H1-H2|≤5mm.

16. The battery pack according to claim 6, wherein: The height of the surface of the busbar for bonding with the insulating layer relative to the end face is H1, and the height of the surface of the bracket for bonding with the insulating layer relative to the end face is H2, wherein H1≤H2.

17. The battery pack according to claim 6, wherein: The insulating layer includes mica paper.

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