Battery pack

Abstract

A battery pack, comprising a case, a battery module, and a partition plate. The case comprises a cover plate, a bottom plate, and a side beam. The cover plate, the bottom plate, and the side beam define an accommodating cavity. The partition plate is arranged in the accommodating cavity and divides the accommodating cavity into a battery accommodating cavity and a first exhaust space. The partition plate is provided with a plurality of exhaust through holes arranged in an array. The battery module is arranged in the battery accommodating cavity. The battery module comprises a plurality of battery cells in one-to-one correspondence with the exhaust through holes. Each battery cell is provided with a casing. The casing is provided with a first surface facing the partition plate. The first surface is provided with an explosion-proof valve plate. The orthographic projection of the explosion-proof valve plate on the partition plate is at least partially located in the exhaust through hole corresponding to the battery cell comprising the explosion-proof valve plate. The explosion-proof valve plate is provided with a plurality of bursting notches extending in the radial direction thereof. The explosion-proof valve plate is configured to be able to be cracked along the bursting notches when actuated and form a plurality of outwardly folded pieces to block the hole wall of the exhaust through hole. The outer surface of the explosion-proof valve plate is covered with a first insulating layer.

Description

Battery pack

[0001] Cross-reference to related applications

[0002] The present application claims priority to the Chinese patent application No. 202422424561.6, filed on September 30, 2024, and entitled "Battery pack", the content of which is incorporated herein by reference in its entirety. TECHNICAL FIELD

[0003] The present application relates to the technical field of batteries, in particular to a battery pack. BACKGROUND

[0004] The battery pack used in new energy vehicles usually includes a plurality of battery monomers (battery cells), and an explosion-proof valve is arranged on each battery monomer. When the battery monomer is in thermal runaway, the explosion-proof valve will burst open, and the spewing material (when the battery monomer is in thermal runaway, the internal temperature can reach more than 200 degrees Celsius, so the spewing material can include high-temperature gas, molten material, etc.) will spew out. If it is allowed to run among other battery monomers, its high-temperature and high-pressure characteristics will affect the stability of other battery monomers, and even cause safety problems such as heat spread. In the prior art, an exhaust passage is designed in the battery pack to solve this problem. The exhaust passage is separated from the area where the battery monomers are located by a separation component. By arranging, for example, an exhaust through hole on the separation component, the spewing material from the burst open of the explosion-proof valve of the battery monomer can pass through the separation component into the exhaust passage, and the spewing material can be dispersed through the exhaust passage, thereby solving the problem of the negative impact of high-temperature and high-pressure spewing material on other battery monomers.

[0005] However, it is found in the experiment that the spewing material is easy to cause a short circuit problem in the battery pack after contacting other charged objects because the spewing material is an internal substance of the battery monomer and has conductivity, thereby causing a more serious thermal runaway chain reaction. To solve the problem of short circuit caused by the spewing material in the battery pack, the prior art coats an insulating layer in the exhaust passage for insulation. In addition, if the separation component is a metal part, insulation treatment is also performed on both sides of the separation component. However, the existing process cannot guarantee that the hole wall part of the exhaust through hole on the separation component is completely covered by the insulating layer, and there is a risk of short circuit caused by the contact between the spewing material of the battery monomer and the hole wall of the exhaust through hole.

[0006] Therefore, there is an urgent need for a battery pack to solve the above problems. SUMMARY

[0007] The purpose of the present application is to provide a battery pack to solve the problem of short circuit caused by the contact between the spewing material and the hole wall when the battery monomer is in thermal runaway.

[0008] To achieve this purpose, the present application adopts the following technical solution:

[0009] A battery pack comprises:

[0010] A box body comprising a cover plate, a bottom plate and a side beam, the cover plate, the bottom plate and the side beam surrounding a containing cavity;

[0011] A partition plate arranged in the containing cavity and separating the containing cavity into a battery containing cavity and a first exhaust space, the partition plate being provided with a plurality of exhaust through holes arranged in an array, the plurality of exhaust through holes respectively communicating the battery containing cavity and the first exhaust space;

[0012] A battery pack arranged in the battery containing cavity, the battery pack comprising a plurality of battery monomers, each of the plurality of battery monomers having a shell, the shell having a first surface facing the partition plate, the first surface being provided with an explosion-proof valve piece, the explosion-proof valve piece being correspondingly arranged with one of the plurality of exhaust through holes, and the orthogonal projection of the explosion-proof valve piece on the partition plate being located in the corresponding one of the plurality of exhaust through holes, the explosion-proof valve piece being provided with a plurality of explosion score lines extending radially thereon, when one of the plurality of battery monomers is in thermal runaway, the explosion-proof valve piece arranged thereon can be cracked along the explosion score lines of the explosion-proof valve piece and form a plurality of outwardly folded pieces to shield the hole wall of the corresponding one of the plurality of exhaust through holes, and the outer surface of the explosion-proof valve piece is provided with a first insulating layer.

[0013] As an improvement of the above technical solution, the orthogonal projection of the explosion score line on the partition plate is located in the corresponding one of the plurality of exhaust through holes comprising the explosion-proof valve piece, the plurality of explosion score lines intersect at a cross point, and the cross point is located on the center line of the corresponding one of the plurality of exhaust through holes comprising the explosion-proof valve piece.

[0014] As an improvement of the above technical solution, the explosion-proof valve piece is provided with two explosion score lines, and the included angle between the two explosion score lines is 90°.

[0015] As an improvement of the above technical solution, the cross point of the plurality of explosion score lines on the explosion-proof valve piece is the midpoint of each explosion score line.

[0016] As an improvement of the above technical solution, taking the cross point as the center, along the same radial direction of the explosion-proof valve piece, the distance from the cross point to the end point of the explosion score line is L1, the distance from the cross point to the edge of the explosion-proof valve piece is L2, and it satisfies: 0.5≤L1 / L2≤0.8.

[0017] As an improvement of the above technical solution, the explosion-proof valve piece comprises an explosion zone, the explosion score line is arranged in the explosion zone, the thickness of the explosion score line is D1, the thickness of the explosion zone is D2, and it satisfies: 0.05≤D1 / D2≤0.4.

[0018] The explosion-proof valve plate is covered with a second insulation layer on the side facing the inside of the plurality of battery monomers; or the explosion-proof valve plate is a high-temperature-resistant insulation explosion-proof valve plate.

[0019] As an improvement of the above technical solution, a first communication hole is arranged on the side beam, the first communication hole communicates the outside of the box with the first exhaust space, and the first communication hole is provided with the pressure relief valve away from the first exhaust space.

[0020] As an improvement of the above technical solution, a support frame is arranged on the bottom plate and used for supporting the partition plate, so that the first exhaust space is formed between the partition plate and the bottom plate.

[0021] As an improvement of the above technical solution, a cooling flow channel for cooling medium circulation is arranged in the partition plate.

[0022] As an improvement of the above technical solution, the first surface is located at the bottom of one of the plurality of battery monomers.

[0023] As an improvement of the above technical solution, the battery pack further comprises a CCS (Cells Contact System) assembly arranged between the battery group and the cover plate and used for series connection or parallel connection of the plurality of battery monomers.

[0024] As an improvement of the above technical solution, the side beam has a second exhaust space in communication with the first exhaust space, and the first communication hole communicates with the first exhaust space through the second exhaust space.

[0025] As an improvement of the above technical solution, a plurality of first communication holes are arranged, and the plurality of first communication holes are arranged at intervals along the extension direction of the side beam.

[0026] As an improvement of the above technical solution, the battery pack further comprises a protective cover body fixedly arranged on the outer wall of the side beam and corresponding to the first communication hole.

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

[0028] The battery pack of the present application, the outer surface of the explosion-proof valve sheet has a first insulating layer, when a battery monomer has thermal runaway, the explosion-proof valve sheet breaks along the explosion mark and forms a plurality of outwardly folded sheet bodies to shield the hole wall of the exhaust hole, avoiding the contact of the spewing material with the hole wall of the exhaust hole, and because the outer surface of the explosion-proof valve sheet is covered with the first insulating layer, the explosion-proof valve sheet and the hole wall will not be in conductive communication, thereby solving the problem of short circuit caused by the contact of the spewing material with the hole wall when the battery monomer has thermal runaway, and improving the safety of the battery pack. BRIEF DESCRIPTION OF DRAWINGS

[0029] Fig. 1 is a structural schematic diagram of a battery pack provided by an embodiment of the present application;

[0030] Fig. 2 is an exploded view of a battery pack provided by an embodiment of the present application;

[0031] Fig. 3 is a structural schematic diagram of a battery monomer provided by an embodiment of the present application;

[0032] Fig. 4 is a structural schematic diagram of a battery monomer provided by an embodiment of the present application;

[0033] Fig. 5 is a schematic diagram of part of the structure of a battery pack after the explosion-proof valve sheet breaks open provided by an embodiment of the present application;

[0034] Fig. 6 is a sectional view of part of the structure of a battery pack provided by an embodiment of the present application;

[0035] Fig. 7 is an enlarged view of A in Fig. 6.

[0036] In the drawings: 1, box body; 11, cover plate; 12, bottom plate; 13, edge beam; 131, first communication hole; 132, second exhaust space; 2, battery pack; 21, battery monomer; 211, explosion-proof valve sheet; h, explosion mark; 2111, first explosion mark; 2112, second explosion mark; 2113, outer surface; 2114, explosion area; 212, shell; 2121, first surface; 3, partition plate; 31, exhaust hole; 311, hole wall; 32, cooling flow channel; 4, pressure relief valve; 5, protective cover; 6, support frame; 7, CCS assembly; 100, containing cavity; 10, first exhaust space; 20, battery containing cavity. DETAILED DESCRIPTION

[0037] The specific embodiments of the present application will be further described in detail below in conjunction with the drawings and examples. The following examples are used to illustrate the present application, but are not used to limit the scope of the present application.

[0038] In the description of the application, unless otherwise explicitly specified and limited, the terms "connected", "connected", "fixed" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the application can be understood according to the specific circumstances.

[0039] In the present application, unless otherwise explicitly specified and limited, the first feature "on" or "under" the second feature can include that the first and second features are in direct contact, or that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, the first feature "on", "above" and "above" the second feature includes that the first feature is directly above and obliquely above the second feature, or only indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature "under", "below" and "below" the second feature includes that the first feature is directly below and obliquely below the second feature, or only indicates that the horizontal height of the first feature is less than that of the second feature.

[0040] In the description of the present embodiment, the terms "up", "down", "right", and other orientation or position relationships are based on the orientation or position relationship shown in the drawings, and are only for the convenience of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second" are only used to distinguish in the description, and have no special meaning.

[0041] As shown in FIGS. 1-7, the present embodiment provides a battery pack, which comprises a box 1, a battery group 2 and a partition plate 3. The box 1 comprises a cover plate 11, a bottom plate 12 and a side beam 13, which surround to form a receiving cavity 100. The partition plate 3 is arranged in the receiving cavity 100 and separates the receiving cavity 100 into a battery receiving cavity 20 and a first exhaust space 10. The partition plate 3 is provided with a plurality of exhaust through holes 31 arranged in an array, and each of the exhaust through holes 31 communicates the battery receiving cavity 20 and the first exhaust space 10. The battery group 2 is arranged in the battery receiving cavity 20, and the battery group 2 comprises a plurality of battery monomers 21 corresponding to the exhaust through holes 31. The battery monomer 21 has a shell 212, and the shell 212 has a first surface 2121 facing the partition plate 3. The first surface 2121 is provided with an anti-explosion valve sheet 211, and the orthographic projection of the anti-explosion valve sheet 211 on the partition plate 3 is at least partially located in the exhaust through hole 31 corresponding to the battery monomer 21. The anti-explosion valve sheet 211 is provided with a plurality of explosion notches h extending in the radial direction thereof, and the anti-explosion valve sheet 211 is configured to be broken along the explosion notches h and form a plurality of outwardly folded sheet bodies to shield the hole wall 311 of the exhaust through hole 31 when opened. The outer surface 2113 of the anti-explosion valve sheet 211 is covered with a first insulating layer. The anti-explosion valve sheet 211 is configured to respond to the battery monomer 21 and break to allow the discharge from the inside of the battery monomer 21 to pass through. The first exhaust space 10 is used to collect the discharge (i.e., the eruption material), and the discharge enters the first exhaust space 10 through the exhaust through hole 31.

[0042] The battery pack of the present embodiment, the anti-explosion valve sheet 211 has the first insulating layer at least on the outer surface 2113. When the thermal runaway occurs in the battery monomer 21, the anti-explosion valve sheet 211 breaks along the explosion notches h and forms a plurality of outwardly folded sheet bodies to shield the hole wall 311 of the exhaust through hole 31, avoiding the contact between the eruption material and the hole wall 311. Due to the first insulating layer covering the outer surface 2113 of the anti-explosion valve sheet 211, the anti-explosion valve sheet 211 and the hole wall 311 do not conductively communicate, thereby solving the problem of short circuit caused by the contact between the eruption material and the hole wall 311 when the thermal runaway of the battery monomer 21 occurs, and improving the safety of the battery pack.

[0043] In other embodiments, the anti-explosion valve sheet 211 can be made of an insulating material.

[0044] Optionally, as shown in FIG. 5, the orthographic projection of each of the blasting score lines h on the separator plate 3 is located within the exhaust vent hole 31 corresponding to the battery cell 21 including the same, and the intersection points of the plurality of blasting score lines h are located on the center line of the exhaust vent hole 31 corresponding to the battery cell 21 including the same. That is to say, the orthographic projection of the blasting score line h on the separator plate 3 does not extend outside the exhaust vent hole 31 corresponding to the battery cell 21 including the same. When the battery cell 21 is in thermal runaway, the explosion-proof valve sheet 211 breaks at the blasting score line h to form a plurality of sheet bodies with a shape close to a triangle, and the orthographic projection of the blasting score line h on the separator plate 3 does not extend outside the exhaust vent hole 31 corresponding to the battery cell 21 including the same, which can avoid the crack of the explosion-proof valve sheet 211 after breaking extending to the area above the separator plate 3 which is not provided with the exhaust vent hole 31, thereby reducing the probability of the battery cell 21 spatter from the crack of the explosion-proof valve sheet 211 to the separator plate 3. In other embodiments, the plurality of radial blasting score lines h on the explosion-proof valve sheet 211 can also not intersect at a point, but a circular or polygonal blasting score line is additionally provided in the central region of the explosion-proof valve sheet 211, the plurality of radial blasting score lines h on the explosion-proof valve sheet 211 are arranged along the circumference of the circular or polygonal blasting score line, and one end of the radial blasting score line h on the explosion-proof valve sheet 211 is connected to the circular blasting score line or the vertex of the polygonal blasting score line, and the other end extends to the edge region of the explosion-proof valve sheet 211; when the battery cell 21 is in thermal runaway, the region surrounded by the circular or polygonal blasting score line on the explosion-proof valve sheet 211 falls off, the remaining part of the explosion-proof valve sheet 211 breaks along the radial blasting score lines h thereof and forms a plurality of outwardly folded sheet bodies to shield the hole wall 311 of the exhaust vent hole 31. However, this way of additionally providing a circular or polygonal blasting score line will lose part of the sheet body (the region surrounded by the circular or polygonal blasting score line on the explosion-proof valve sheet 211 falls off) when the explosion-proof valve sheet 211 breaks, resulting in a smaller area of the sheet body outwardly folded to shield the hole wall 311 of the exhaust vent hole 31, which will reduce the shielding effect on the hole wall 311 of the exhaust vent hole 31. In the present embodiment, the plurality of radial blasting score lines h on the explosion-proof valve sheet 211 intersect at a point, so that the explosion-proof valve sheet 211 will not lose part of the sheet body when it breaks, which is conducive to improving the shielding effect on the hole wall 311 of the exhaust vent hole 31.

[0045] Further, as shown in FIG. 3 and FIG. 4, the intersection points of the blasting score lines h on the explosion-proof valve sheet 211 are the midpoints of the blasting score lines h, so that the explosion-proof valve sheet 211 can form a plurality of sheet bodies with substantially consistent shape and size after breaking along the blasting score lines h, thereby ensuring the shielding effect of each sheet body on the hole wall 311 of the exhaust vent hole 31. Specifically, in the present embodiment, the intersection points of the blasting score lines h on the explosion-proof valve sheet 211 are located at the center of the outer surface 2113 of the explosion-proof valve sheet 211.

[0046] Optionally, as shown in FIG. 3 and FIG. 4, each of the explosion-proof valve pieces 211 is provided with two explosion score lines h, and the included angle between the two explosion score lines h is 90°, that is, the two explosion score lines h on the same explosion-proof valve piece 211 are perpendicular to each other. The two explosion score lines h are respectively a first explosion score line 2111 and a second explosion score line 2112, and the first explosion score line 2111 is perpendicular to the second explosion score line 2112. In other embodiments, more explosion score lines h intersecting at a point can also be provided, but too many explosion score lines h will reduce the overall structural strength of the explosion-proof valve piece 211, which is not conducive to the improvement of the service life of the battery monomer 21, and when the explosion-proof valve piece 211 is cracked, it is also easier to cause part of the piece to be torn off, which will reduce the shielding effect of the cracked explosion-proof valve piece 211 on the hole wall 311 of the exhaust passage 31. The embodiment sets two cross-shaped explosion score lines h on the explosion-proof valve piece 211, which has less effect on the overall structural strength of the explosion-proof valve piece 211, and has a good shielding effect on the hole wall 311 of the exhaust passage 31 after cracking.

[0047] In an embodiment, the explosion-proof valve piece 211 is a regular shape, such as a square, a circle, a waist-round shape (the waist-round shape is a shape formed by two semicircular end portions connected by parallel straight lines), etc. The intersection point of the explosion score lines is located at the center of the explosion-proof valve piece 211, and the intersection point is taken as the center. In the same radial direction of the explosion-proof valve piece 211, the distance from the intersection point to the end point of the explosion score line h in the radial direction is L1, and the distance from the intersection point to the edge of the explosion-proof valve piece 211 in the radial direction is L2, and it satisfies: 0.5≤L1 / L2≤0.8.

[0048] Specifically, L1 / L2 can be 0.5, 0.6, 0.65, 0.7, 0.8. If L1 is too short, i.e. L1 / L2<0.5, it means that the explosion score line h is too short, which increases the difficulty of breaking the explosion-proof valve piece 211. If L1 / L2>0.8, it means that the explosion score line h is too long, and the piece formed after the explosion-proof valve piece 211 is broken is easy to fall off instead of being adhered to the explosion-proof valve piece 211, so it cannot shield the hole wall 311 of the corresponding exhaust passage 31 of the battery monomer 21 including it.

[0049] In another embodiment, the explosion-proof valve piece 211 includes an explosion zone 2114, and the explosion zone 2114 is located in the middle of the explosion-proof valve piece 211 and is used to set the explosion score line. The thickness of the explosion score line h is D1, and the thickness of the explosion zone 2114 is D2, and it satisfies: 0.05≤D1 / D2≤0.4.

[0050] Specifically, the burst notch h is formed by thinning the thickness of the burst area 2114, and D1 / D2 can be 0.05, 0.1, 0.2, 0.3, etc. If the thickness of the burst notch h is too small, D1 / D2 < 0.05, that is, the explosion-proof valve is too thin and easily broken. If the thickness of the burst notch h is too large, D1 / D2 > 0.4, that is, the explosion-proof valve is difficult to open.

[0051] Optionally, the normal projection of the explosion-proof valve piece 211 on the partition plate 3 is located in the exhaust hole 31 corresponding to the battery monomer 21, that is, the cross-sectional size of the exhaust hole 31 is larger than the size of the explosion-proof valve piece 211, so as to avoid the crack extending to the area above the partition plate 3 not provided with the exhaust hole 31 after the explosion-proof valve piece 211 is broken, thereby further reducing the probability of the battery monomer 21 spattering to the partition plate 3 from the crack after the burst notch h is broken.

[0052] In the embodiment, the partition plate 3 is located below the battery pack 2, the battery pack 2 is arranged on the partition plate 3, and the first surface 2121 of the battery monomer 21 is located at the bottom of the battery monomer 21, so that the discharge material is spattered downward when the battery monomer 21 is out of control, thereby further reducing the probability of the spattering material contacting the hole wall 311 of the exhaust hole 31.

[0053] Optionally, the side of the explosion-proof valve piece 211 facing the inside of the battery monomer 21 is covered with a second insulating layer. When the explosion-proof valve piece 211 is broken, part of the piece body may be rolled over. In order to avoid the rolled piece body contacting the hole wall 311 of the exhaust hole 31 and conducting electricity, the side of the explosion-proof valve piece 211 facing the inside of the battery monomer 21 is covered with a second insulating layer in the embodiment, so that the inside and outside of the explosion-proof valve piece 211 have good insulating effect. In the embodiment, the first insulating layer and the second insulating layer can be coated with insulating powder or attached with a blue film or the like.

[0054] Optionally, as shown in FIGS. 6 and 7, the battery pack provided in the embodiment further comprises a pressure relief valve 4, the side beam 13 is provided with a first communication hole 131, the first communication hole 131 communicates the outside of the box body 1 with the first exhaust space 10, and the side of the first communication hole 131 away from the first exhaust space 10 is provided with the pressure relief valve 4. When the battery monomer 21 is out of control, the explosion-proof valve piece 211 is broken, the spattering material generated by the battery monomer 21 enters the first exhaust space 10 through the broken explosion-proof valve piece 211 and the corresponding exhaust hole 31, the pressure in the first exhaust space 10 increases, and when the pressure in the first exhaust space 10 increases to the opening pressure threshold of the pressure relief valve 4, the pressure relief valve 4 on the side beam 13 opens, and the spattering material can be discharged from the battery pack through the first communication hole 131. The first communication hole 131 is arranged on the side beam 13, which can avoid the spattering material spattering upward into the cab, thereby improving the safety of the vehicle.

[0055] Further, as shown in FIG. 6 and FIG. 7, the edge beam 13 is provided with a second exhaust space 132 in communication with the first exhaust space 10, and the first communication hole 131 is in communication with the first exhaust space 10 through the second exhaust space 132. By connecting the first exhaust space 10 and the first communication hole 131 through the second exhaust space 132, the position of the first communication hole 131 can be selected as needed, without being arranged in the lower region of the partition plate 3 as the first exhaust space 10, which is conducive to reducing the overall thickness of the battery pack. In the present embodiment, the first communication hole 131 is located above the partition plate 3, the first exhaust space 10 extends to below the second exhaust space 132, and the bottom of the second exhaust space 132 is in communication with the first exhaust space 10.

[0056] Further, the first communication hole 131 is provided in plurality, the plurality of first communication holes 131 are arranged at intervals along the extension direction of the edge beam 13, and the pressure relief valve 4 and the second exhaust space 132 are arranged one by one corresponding to the first communication hole 131. The plurality of first communication holes 131 cooperate with the corresponding pressure relief valve 4 and second exhaust space 132, so that when the battery monomer 21 at each position occurs thermal runaway, the spewing material can be discharged in time through the first communication hole 131.

[0057] Optionally, as shown in FIG. 1, the battery pack further comprises a protective cover 5, which is fixedly arranged on the outer wall of the edge beam 13 and arranged one by one corresponding to the first communication hole 131, and the protective cover 5 covers the corresponding first communication hole 131 and pressure relief valve 4.

[0058] Optionally, as shown in FIG. 2, the battery pack further comprises a support frame 6, which is arranged on the bottom plate 12 and used to support the partition plate 3, so that the first exhaust space 10 is formed between the partition plate 3 and the bottom plate 12, and the support frame 6 and the partition plate 3 are adhesively connected by structural glue.

[0059] Further, as shown in FIG. 2, the support frame 6 is provided in plurality, and the plurality of support frames 6 are arranged at intervals along the length direction of the bottom plate 12, so that the partition plate 3 can be more uniformly stressed.

[0060] Optionally, as shown in FIG. 7, the partition plate 3 is made of metal material, and the partition plate 3 is provided with a cooling flow channel 32 for flowing of cooling medium. That is to say, the partition plate 3 is also a liquid cooling plate. The cooling liquid flowing in the liquid cooling plate can cool the battery monomer 21, and also can cool and cool the spewing material entering the first exhaust space 10, so as to effectively control the temperature and reduce the influence on other battery monomers 21 in the temperature level. The partition plate 3 is adhesively connected to the bottom of the battery monomer 21 by structural glue.

[0061] Optionally, as shown in FIG. 2, the battery pack provided by the embodiment further comprises a CCS (Cells Contact System) component 7, which is arranged between the battery pack 2 and the cover plate 11, and is used for series and parallel connection of the battery monomers 21 and acquisition of temperature and pressure signals.

[0062] The above merely describes the preferred embodiments of the present application, and it should be noted that, for those skilled in the art, without departing from the technical principles of the present application, a number of improvements and replacements can be made, and these improvements and replacements should also be considered as the protection scope of the present application.

Claims

1. A battery pack, comprising: a box body (1) comprising a cover plate (11), a bottom plate (12) and a side beam (13), the cover plate (11), the bottom plate (12) and the side beam (13) surrounding a containing cavity (100); a partition plate (3) arranged in the containing cavity (100) and separating the containing cavity (100) into a battery containing cavity (20) and a first exhaust space (10), the partition plate (3) being provided with a plurality of exhaust through holes (31) arranged in an array, the plurality of exhaust through holes (31) each communicating the battery containing cavity (20) and the first exhaust space (10); a battery pack (2) arranged in the battery containing cavity (20), the battery pack (2) comprising a plurality of battery monomers (21), each of the plurality of battery monomers (21) having a shell (212) with a first face (2121) facing the partition plate (3), the first face (2121) being provided with an explosion-proof valve piece (211), the explosion-proof valve piece (211) being arranged corresponding to one of the plurality of exhaust through holes (31), and the orthogonal projection of the explosion-proof valve piece (211) on the partition plate (3) being located in the corresponding one of the plurality of exhaust through holes (31), the explosion-proof valve piece (211) being provided with a plurality of explosion score lines (h) extending radially thereon, when one of the plurality of battery monomers (21) is in thermal runaway, the explosion-proof valve piece (211) arranged thereon can be cracked along the explosion score lines (h) of the explosion-proof valve piece (211) and form a plurality of outwardly folded pieces to shield the hole wall (311) of the corresponding one of the plurality of exhaust through holes (31), and an outer surface (2113) of the explosion-proof valve piece (211) is provided with a first insulation layer.

2. The battery pack of claim 1, wherein, Orthogonal projections of the explosion score lines (h) on the partition plate (3) are each located in the one of the plurality of exhaust through holes (31) corresponding to the explosion-proof valve piece (211) comprising the explosion score line (h), a plurality of the explosion score lines (h) intersect at a cross point, and the cross point is located on a center line of the one of the plurality of exhaust through holes (31) corresponding to the explosion-proof valve piece (211) comprising the explosion score line (h).

3. The battery pack of claim 2, wherein, The explosion-proof valve piece (211) is provided with two explosion score lines (h), and an included angle between the two explosion score lines (h) is 90°.

4. The battery pack of claim 2, wherein, The cross point of a plurality of the explosion score lines (h) on the explosion-proof valve piece (211) is a midpoint of each of the explosion score lines (h).

5. The battery pack of claim 4, wherein, Taking the cross point as a center, along the same radial direction of the explosion-proof valve piece (211), a distance from the cross point to an end point of the explosion score line (h) is L1, a distance from the cross point to an edge of the explosion-proof valve piece (211) is L2, and 0.5≤L1 / L2≤0.8 is satisfied.

6. The battery pack of claim 2, wherein, The explosion-proof valve piece (211) comprises an explosion zone (2114), the explosion notch (h) is arranged in the explosion zone (2114), the thickness of the explosion notch (h) is D1, the thickness of the explosion zone (2114) is D2, and the following condition is met: 0.05<=D1 / D2<=0.

4.

7. The battery pack of claim 1, wherein, The explosion-proof valve piece (211) is covered with a second insulation layer on the side facing the inside of the plurality of battery monomers (21); or The explosion-proof valve piece (211) is a high-temperature-resistant insulation explosion-proof valve piece.

8. The battery pack of any one of claims 1-7, wherein, Further comprising a pressure relief valve (4), the edge beam (13) is provided with a first communication hole (131), the first communication hole (131) communicates the outside of the box (1) with the first exhaust space (10), and the first communication hole (131) is used for arranging the pressure relief valve (4).

9. The battery pack of claim 1, wherein, Further comprising a support frame (6), the support frame (6) is arranged on the bottom plate (12) and is used for supporting the partition plate (3), so that the first exhaust space (10) is formed between the partition plate (3) and the bottom plate (12).

10. The battery pack of any one of claims 1-7, wherein, The partition plate (3) is provided with a cooling flow channel (32) for the circulation of cooling medium.

11. The battery pack of claim 1, wherein, The first surface (2121) is located at the bottom of one of the plurality of battery monomers (21).

12. The battery pack of claim 11, wherein, The battery pack further comprises a CCS (Cells Contact System) assembly (7), the CCS assembly (7) is arranged between the battery group (2) and the cover plate (11) and is used for the series connection or parallel connection of the plurality of battery monomers (21).

13. The battery pack of claim 8, wherein, The edge beam (13) has a second exhaust space (132) in communication with the first exhaust space (10), and the first communication hole (131) communicates with the first exhaust space (10) through the second exhaust space (132).

14. The battery pack of claim 8, wherein, The first communication hole (131) is arranged in plurality, and the plurality of first communication holes (131) are arranged at intervals along the extension direction of the edge beam (13).

15. The battery pack of claim 13, wherein, The battery pack further comprises a protective cover (5); the protective cover (5) is fixedly arranged on the outer wall of the edge beam (13) and is arranged one-to-one with the first communication hole (131).

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