Battery monomer and battery pack

Abstract

The invention provides a battery monomer and a battery pack, and relates to the technical field of batteries. The single battery comprises a shell with an opening, a pole penetrating through the shell, an electrode assembly arranged in the shell and electrically connected with the pole, an end cover connected with the shell to seal the opening, and an anti-explosion valve arranged on the end cover. The shell is of an integrally-formed structure, the end cover and the pole are oppositely arranged in the first direction, an exhaust groove is formed in the side, close to the electrode assembly, of the end cover, and the anti-explosion valve and the exhaust groove are oppositely arranged in the first direction. According to the battery monomer provided by the invention, the position of the pole is not a weak area of the shell any more, so that the shell has higher structural strength at the position, and higher internal pressure of the shell can be resisted; and the exhaust groove on the end cover is convenient for evacuating high-temperature and high-pressure gas in the shell to the anti-explosion valve to be exhausted so as to reduce the internal pressure of the shell. Therefore, the safety of the battery monomer is improved.

Description

Technical Field

[0001] This application relates to the technical field of batteries, and particularly to a battery cell and a battery pack. Background Art

[0002] The battery cell is an important component module of the battery pack. In order to reduce the double failure risks of electrical insulation and thermal runaway, the battery cell usually adopts a thermoelectric separation design, arranging the terminal post on the end cover at the opening position of the housing and arranging the explosion-proof valve on the housing. However, when the battery cell undergoes thermal runaway, some of the gas in the housing is prone to gather towards the terminal post under heat. Due to the existence of the opening, the connection area between the end cover and the housing opening is a weak area. When the internal pressure of the housing continues to rise, the high-pressure gas blows off the end cover, causing the battery cell to explode, thus affecting the safety of the battery cell. Summary of the Invention

[0003] In view of this, the purpose of this application is to provide a battery cell and a battery pack, aiming to solve the technical problem of how to improve the safety of the battery cell.

[0004] To achieve the above purpose, the technical solution adopted in this application is as follows: In a first aspect, an embodiment of this application provides a battery cell having a first direction and including: A housing, which is an integrally formed structure and has an opening; A terminal post passing through the housing; An electrode assembly disposed inside the housing and electrically connected to the terminal post; An end cover connected to the housing to seal the opening. The end cover and the terminal post are oppositely disposed along the first direction, and an exhaust groove is provided on the side of the end cover close to the electrode assembly; An explosion-proof valve disposed on the end cover. The explosion-proof valve and the exhaust groove are oppositely disposed along the first direction.

[0005] In one of the embodiments of the first aspect, a plurality of support protrusions are provided on the side of the end cover close to the electrode assembly. The plurality of support protrusions are spaced apart and disposed in the exhaust groove. The support protrusions and the explosion-proof valve are spaced apart, and the support protrusions are in contact with the electrode assembly.

[0006] In one of the embodiments of the first aspect, the battery cell has a second direction perpendicular to the first direction. The positive projections of two adjacent support protrusions along the second direction on a plane perpendicular to the second direction at least partially overlap.

[0007] In one embodiment of the first aspect, a plurality of the support protrusions are connected to the side wall of the exhaust groove. Each of the support protrusions extends in a direction close to the explosion-proof valve, and an arc surface is formed on a side of each of the support protrusions close to the electrode assembly, and the arc surface abuts against the electrode assembly.

[0008] In one embodiment of the first aspect, a part of the plurality of support protrusions are connected to the bottom wall of the exhaust groove, and a circular surface is formed on a side of this part of the support protrusions close to the electrode assembly, and the circular surface abuts against the electrode assembly; another part of the plurality of support protrusions are connected to the side wall of the exhaust groove, and a semi-circular surface is formed on a side of this part of the support protrusions close to the electrode assembly, and the semi-circular surface abuts against the electrode assembly.

[0009] In one embodiment of the first aspect, the battery cell has a third direction that is perpendicular to each of the first direction and the second direction. The plurality of support protrusions are arranged at intervals in the second direction. Each of the support protrusions extends in the third direction, and an elliptical surface is formed on a side of each of the support protrusions close to the electrode assembly, and the elliptical surface abuts against the electrode assembly.

[0010] In one embodiment of the first aspect, a first reinforcing protrusion located in the exhaust groove is provided on a side of the end cover close to the electrode assembly. The first reinforcing protrusion and the support protrusions are arranged at intervals, and the first reinforcing protrusion is arranged along the circumference of the explosion-proof valve.

[0011] In one embodiment of the first aspect, the first reinforcing protrusion surrounds the explosion-proof valve. The vertical distance from a side of the first reinforcing protrusion close to the electrode assembly to the bottom wall of the exhaust groove is H1 mm, and the vertical distance from a side of each of the support protrusions close to the electrode assembly to the bottom wall of the exhaust groove is H2 mm, satisfying: H1 < H2.

[0012] In one embodiment of the first aspect, a notch penetrating through the first reinforcing protrusion is provided on the first reinforcing protrusion, and the notch communicates with the exhaust groove.

[0013] In one embodiment of the first aspect, a plurality of grooves are provided on a side of the end cover away from the electrode assembly. Adjacent two of the grooves are arranged at intervals, and the grooves and the exhaust groove are arranged opposite to each other in the first direction.

[0014] In one of the embodiments of the first aspect, a second reinforcing protrusion is provided on a side of the end cover away from the electrode assembly, the groove and the second reinforcing protrusion are arranged at intervals, the second reinforcing protrusion is located at the edge of the end cover and is arranged around the explosion-proof valve, and the second reinforcing protrusion is connected to the shell.

[0015] In one embodiment of the first aspect, the battery cell has a second direction perpendicular to the first direction, a notched groove is provided on a side of the end cap away from the electrode assembly, the notched groove and the explosion-proof valve are spaced apart along the second direction, and the notched groove and the exhaust groove are oppositely arranged along the first direction.

[0016] In one embodiment of the first aspect, the number of the scored grooves is multiple, the multiple scored grooves are spaced apart along the second direction, and the scored grooves and the explosion-proof valve are spaced apart along the second direction. In a second aspect, an embodiment of the present application provides a battery pack, comprising a separator and a battery cell as described in any embodiment of the first aspect, the end cap is disposed on the separator, the separator is provided with a vent extending along the first direction, and the vent and the explosion-proof valve are disposed opposite each other along the first direction.

[0017] In one embodiment of the second aspect, the end cover and the shell are welded to form a weld, the weld is located on the inner circumference of the shell, and the partition is connected to the weld.

[0018] In one embodiment of the second aspect, the end cover is welded to the shell to form a weld, and the weld is located on the outer peripheral side of the shell. A protruding structure is provided on the side of the partition close to the end cover, and the vertical distance from the side of the protruding structure close to the pole to the partition is H3mm, and the vertical distance from the side of the weld close to the pole to the partition is H4mm, satisfying: H3>H4, and the protruding structure is connected to the weld.

[0019] The beneficial effects of this application are as follows: The battery cell provided in this application has an integrally molded housing, an end cap connected to the housing to seal the housing opening, an explosion-proof valve disposed on the end cap, and a pole extending through the housing. The end cap and pole are disposed relative to each other along a first direction, thereby also achieving thermal and electrical separation. Furthermore, the location of the pole is no longer a weak point in the housing, giving the housing a higher structural strength at that location, thereby enabling it to withstand greater internal pressure within the housing. Furthermore, an exhaust groove is disposed on the side of the end cap close to the electrode assembly, and the exhaust groove and explosion-proof valve are disposed relative to each other along the first direction. This facilitates the evacuation of high-temperature, high-pressure gas within the housing to the explosion-proof valve for discharge, thereby reducing internal pressure within the housing. This improves the safety of the battery cell.

[0020] To make the above - mentioned objects, features, and advantages of the present application more obvious and understandable, the following provides preferred embodiments in conjunction with the accompanying drawings and makes a detailed description as follows. Brief Description of the Drawings

[0021] To more clearly illustrate the technical solutions of the embodiments of the present application, the accompanying drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present application, and thus should not be regarded as limiting the scope. For those of ordinary skill in the art, without creative efforts, other relevant drawings can also be obtained based on these drawings.

[0022] Figure 1 Shows a three - dimensional structural schematic diagram of a battery cell in an embodiment of the present application; Figure 2 Shows Figure 1 the exploded structural schematic Figure 1 ; Figure 3 Shows Figure 1 the exploded structural schematic Figure 2 ; Figure 4 Shows Figure 2 a three - dimensional structural schematic diagram of the end cap in the middle; Figure 5 Shows Figure 2 a perspective structural schematic diagram of the end cap in the middle; Figure 6 Shows Figure 2 another perspective structural schematic diagram of the end cap in the middle; Figure 7 Shows a three - dimensional structural schematic of the end cap of the battery cell in another embodiment of the present application Figure 1 ; Figure 8 Shows a three - dimensional structural schematic of the end cap of the battery cell in another embodiment of the present application Figure 2 ; Figure 9 Shows Figure 8 an enlarged structural schematic diagram of area A in; Figure 10 Shows a perspective structural schematic diagram of the end cap of the battery cell in another embodiment of the present application; Figure 11 Shows another perspective structural schematic diagram of the end cap of the battery cell in another embodiment of the present application; Figure 12 Shows a three - dimensional structural schematic diagram of the end cap of the battery cell in yet another embodiment of the present application; Figure 13 Shows Figure 12 an enlarged structural schematic diagram of area B in; Figure 14 Shows a schematic perspective view of the end cover of a battery cell in another embodiment of the present application; Figure 15 Shows a schematic assembly structure diagram of the battery cells and the separator in a battery pack in an embodiment of the present application; Figure 16 Shows Figure 15 The cross-sectional structure diagram at C-C; Figure 17 Shows Figure 16 The enlarged structure diagram of area D; Figure 18 Shows a schematic assembly structure diagram of the battery cells, the separator and the raised structure in a battery pack in another embodiment of the present application; Figure 19 Shows Figure 18 The cross-sectional structure diagram at E-E; Figure 20 Shows Figure 19 The enlarged structure diagram of area F; Figure 21 Shows a schematic exploded structure diagram of multiple battery cells, the separator and the raised structure in a battery pack in another embodiment of the present application.

[0023] Description of main element symbols: 100 - Battery cell; 110 - Housing; 111 - Opening; 112 - Mounting hole; 120 - Terminal post; 130 - Electrode assembly; 131 - Electrode body; 132 - Tab; 140 - End cover; 141 - Exhaust groove; 142 - Support projection; 1421 - Arc surface; 1422 - Circular surface; 1423 - Semi-circular surface; 1424 - Oval surface; 143 - First reinforcing projection; 144 - Notch; 145 - Groove; 146 - Second reinforcing projection; 147 - Scratch groove; 1471 - Ring groove; 1472 - Non-ring groove; 148 - Weld seam; 150 - Explosion-proof valve; 160 - First insulating part; 170 - Insulating layer; 171 - First ventilation hole; 180 - Protective layer; 181 - Second ventilation hole; 190 - Second insulating part; 200 - Separator; 210 - Exhaust hole; 300 - Raised structure; 310 - Positioning hole; Z - First direction; X - Second direction; Y - Third direction. Detailed description of the specific implementation

[0024] The embodiments of the present application will be described in detail below. The examples of the embodiments are shown in the drawings, where the same or similar reference numerals denote the same or similar elements or elements with the same or similar functions throughout. The embodiments described below by referring to the drawings are exemplary and are only used to explain the present application and should not be construed as a limitation to the present application.

[0025] In the description of the present application, the orientation or positional relationship indicated by terms such as "center", "longitudinal", "transverse", "length", "width", "height", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present application.

[0026] In addition, unless otherwise clearly specified and limited, the first feature being "on" or "under" the second feature may mean that the first feature is in direct contact with the second feature, or the first feature and the second feature are indirectly in contact through an intermediate medium. Moreover, the first feature being "above", "over" and "on top of" the second feature may mean that the first feature is directly above or obliquely above the second feature, or merely indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature being "under", "beneath" and "underneath" the second feature may mean that the first feature is directly below or obliquely below the second feature, or merely indicates that the horizontal height of the first feature is lower than that of the second feature.

[0027] In the description of the present application, terms such as "first", "second", etc. are used to distinguish different objects, and should not be construed as indicating or implying a specific order or primary-secondary relationship, nor implicitly indicating the quantity of the technical features indicated. Thus, features defined with "first", "second" may explicitly or implicitly include one or more of such features. In the description of the present application, the meaning of "a plurality of" is two or more, unless otherwise specifically and clearly defined.

[0028] In the description of the present application, unless otherwise clearly specified and limited, terms such as "mounted", "connected", "coupled", "fixed", etc. should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the internal communication of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific circumstances.

[0029] In the description of the present application, the term "and / or" indicates that three relationships may exist. For example, A and / or B may represent: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / ", generally represents an "or" relationship between the associated objects before and after.

[0030] In the description of the present application, "parallel" not only includes the case of absolute parallelism, but also includes the case of approximately parallelism commonly recognized in engineering; at the same time, "perpendicular" not only includes the case of absolute perpendicularity, but also includes the case of approximately perpendicularity commonly recognized in engineering. Exemplarily, when the included angle between two directions is 80° - 90°, the two directions can be considered perpendicular; when the included angle between two directions is 0° - 10°, the two directions can be considered parallel.

[0031] The battery cell is an important component module of the battery pack. In order to reduce the risk of double failures of electrical insulation and thermal runaway, the battery cell usually adopts a thermoelectric separation design, that is, the pole column is arranged on the end cover at the opening position of the housing, and the explosion-proof valve is arranged on the housing. However, when thermal runaway occurs in the battery cell, some gases in the housing are prone to gather towards the pole column when heated. Since the opening position of the housing is welded and fixed to the end cover, the existence of the opening results in a weak area at the connection area between the end cover and the housing opening. When the internal pressure of the housing continues to rise, the high-pressure gas blows off the end cover, causing the battery cell to explode, thus affecting the safety of the battery cell.

[0032] As Figure 1 shown, to solve the above technical problems, an embodiment of the present application provides a battery cell 100, which relates to the technical field of batteries and is mainly applied in a battery pack to be indirectly applied to an electrical device or an energy storage device in the form of a battery pack. Of course, the battery cell 100 can also be directly applied to an electrical device or an energy storage device without adopting the form of a battery pack, and the application scenarios of the battery cell 100 are not specifically limited herein.

[0033] Exemplarily, the electrical device can be a vehicle, a mobile phone, a portable device, a laptop computer, a ship, a spacecraft, an electric toy, and an electric tool, etc. The vehicle can be a fuel vehicle, a gas vehicle, a new energy vehicle, etc., and the new energy vehicle can be a pure electric vehicle, a hybrid vehicle, and an extended-range vehicle, etc.; the spacecraft can be an airplane, a rocket, a space shuttle, a drone, and a spaceship, etc.; the electric toy includes a fixed or mobile electric toy, for example, a game console, an electric vehicle toy, an electric ship toy, and an electric airplane toy, etc.; the electric tool can be a metal cutting electric tool, a grinding electric tool, an assembly electric tool, and a railway electric tool, etc., for example, an electric drill, an electric grinding wheel, an electric wrench, an electric screwdriver, a hammer drill, an impact electric drill, a concrete vibrator, and an electric planer, etc.; the energy storage device is, for example, an energy storage container, an energy storage power station, etc.; the types of the electrical device and the energy storage device are not specifically limited herein.

[0034] As Figures 1 to 3 shown, the battery cell 100 provided in this embodiment has a first direction Z and includes: a housing 110, a pole column 120, an electrode assembly 130, an end cover 140, and an explosion-proof valve 150.

[0035] Among them, the housing 110 is an integrally formed structure and has an opening 111; the terminal post 120 penetrates through the housing 110; the electrode assembly 130 is disposed inside the housing 110 and is electrically connected to the terminal post 120; the end cap 140 is connected to the housing 110 to seal the opening 111, the end cap 140 and the terminal post 120 are oppositely disposed along the first direction Z, and an exhaust groove 141 is provided on the side of the end cap 140 close to the electrode assembly 130; the explosion-proof valve 150 is disposed on the end cap 140, and the explosion-proof valve 150 and the exhaust groove 141 are oppositely disposed along the first direction Z.

[0036] It should be noted that the housing 110 being an integrally formed structure means that the housing 110 is a structure made by an integral forming process, such as stamping forming, injection molding, die casting forming, extrusion forming, blow molding, 3D printing forming, etc.; the opening 111 formed on the housing 110 made by the integral forming process facilitates the assembly of the electrode assembly 130 into the housing. After the electrode assembly 130 is assembled into the housing, the end cap 140 is connected to the housing 110 to seal the opening 111, so that a closed space is formed inside the housing 110 to be able to encapsulate the electrode assembly 130.

[0037] Exemplarily, the connection between the end cap 140 and the housing 110 can be welding, clamping, bonding, screw connection, roll pressing connection, etc., and no specific limitation is made here.

[0038] It can be understood that for the battery cell 100 provided in this embodiment, since the housing 110 is an integrally formed structure, the end cap 140 is connected to the housing 110 to seal the opening 111 of the housing 110, the explosion-proof valve 150 is disposed on the end cap 140, the terminal post 120 penetrates through the housing 110, and the end cap 140 and the terminal post 120 are oppositely disposed along the first direction Z, in this way, thermoelectric separation is also achieved, and the position where the terminal post 120 is located is no longer the weak area of the housing 110, so that the housing 110 has higher structural strength at this place, thereby being able to withstand a greater internal pressure of the housing 110; at the same time, since an exhaust groove 141 is provided on the side of the end cap 140 close to the electrode assembly 130, and the exhaust groove 141 and the explosion-proof valve 150 are oppositely disposed along the first direction Z, this facilitates evacuating the high-temperature and high-pressure gas inside the housing 110 to the explosion-proof valve 150 for discharge to reduce the internal pressure of the housing 110. Thus, the safety of the battery cell 100 is improved.

[0039] As Figure 2 shown, in one embodiment, a plurality of support protrusions 142 are provided on the side of the end cap 140 close to the electrode assembly 130, the plurality of support protrusions 142 are spaced apart and disposed in the exhaust groove 141, the support protrusions 142 and the explosion-proof valve 150 are spaced apart, and the support protrusions 142 are in contact with the electrode assembly 130.

[0040] It can be understood that since a plurality of support protrusions 142 are provided on the side of the end cap 140 close to the electrode assembly 130, and the electrode assembly 130 is abutted by the plurality of support protrusions 142 respectively to support the electrode assembly 130, this can not only increase the stability of the electrode assembly 130, but also reduce the possibility that the exhaust groove 141 is blocked by the electrode assembly 130 when the battery cell 100 undergoes thermal runaway or is externally impacted, thereby improving the safety of the battery cell 100.

[0041] As Figure 2 , Figure 5 , Figure 10 and Figure 14 shown, further, the battery cell 100 has a second direction X perpendicular to the first direction Z, and the positive projections of two adjacent support protrusions 142 along the second direction X on a plane perpendicular to the second direction X at least partially overlap, so that the plurality of support protrusions 142 can provide better support for the electrode assembly 130 when combined.

[0042] It should be noted that the positive projections of two adjacent support protrusions 142 along the second direction X on a plane perpendicular to the second direction X at least partially overlapping includes: Figure 5 and Figure 10 the partial overlap shown in Figure 14 and the complete overlap shown in

[0043] These two cases, and no specific limitation is made on the type of overlap here.

[0044] As Figure 2 , Figure 4 and Figure 5 shown, in a specific embodiment, a plurality of support protrusions 142 are connected to the side wall of the exhaust groove 141, each support protrusion 142 extends along the direction close to the explosion-proof valve 150, and the side of each support protrusion 142 close to the electrode assembly 130 is an arc surface 1421, and the arc surface 1421 abuts against the electrode assembly 130.

[0045] It can be understood that since multiple supporting protrusions 142 are connected to the side wall of the exhaust groove 141, that is, the positions of the multiple supporting protrusions 142 are at the side wall position of the exhaust groove 141, and each supporting protrusion 142 extends along the direction close to the explosion-proof valve 150, an acute angle α (i.e., 0° < α < 90°) is formed between the side of each supporting protrusion 142 close to the explosion-proof valve 150 and the side wall of the exhaust groove 141. This can reduce the flow resistance of the gas and guide the gas to the explosion-proof valve 150, thereby improving the exhaust performance of the battery cell 100. At the same time, since the orthographic projections of two adjacent supporting protrusions 142 along the second direction X on a plane perpendicular to the second direction X at least partially overlap, and the side of each supporting protrusion 142 close to the electrode assembly 130 is an arc surface 1421 that abuts against the electrode assembly 130, the electrode assembly 130 can be better supported.

[0046] Exemplarily, α can be selected as any value other than 0° and 90°, such as any value or the range between any two values among 1°, 2°, 5°, 8°, 10°, 15°, 18°, 20°, 25°, 30°, 38°, 40°, 45°, 50°, 55°, 60°, 64°, 70°, 80°, 89°. No specific limitation is made here.

[0047] As Figure 7 、 Figure 8 and Figure 10 shown, in another specific embodiment, a part of the multiple supporting protrusions 142 are connected to the bottom wall of the exhaust groove 141, and the side of this part of the supporting protrusions 142 close to the electrode assembly 130 is a circular surface 1422, and the circular surface 1422 abuts against the electrode assembly 130; another part of the multiple supporting protrusions 142 are connected to the side wall of the exhaust groove 141, and the side of this part of the supporting protrusions 142 close to the electrode assembly 130 is a semi-circular surface 1423, and the semi-circular surface 1423 abuts against the electrode assembly 130.

[0048] It can be understood that since a part of the plurality of support protrusions 142 is connected to the bottom wall of the exhaust groove 141, and the side of this part of the support protrusion 142 close to the electrode assembly 130 is a circular surface 1422 that abuts against the electrode assembly 130, that is, this part of the support protrusion 142 at the bottom wall position of the exhaust groove 141 has a circular surface 1422. Another part of the plurality of support protrusions 142 is connected to the side wall of the exhaust groove 141, and the side of this part of the support protrusion 142 close to the electrode assembly 130 is a semi-circular surface 1423 that abuts against the electrode assembly 130, that is, this part of the support protrusion 142 at the side wall position of the exhaust groove 141 has a semi-circular surface 1423. At the same time, the orthographic projections of two adjacent support protrusions 142 along the second direction X on a plane perpendicular to the second direction X at least partially overlap, and thus can also provide good support for the electrode assembly 130.

[0049] As Figure 12 , Figure 13 and Figure 14 shown, in yet another specific embodiment, the battery cell 100 has a third direction Y that is perpendicular to both the first direction Z and the second direction X (i.e., the first direction Z, the second direction X, and the third direction Y are perpendicular to each other pairwise). The plurality of support protrusions 142 are arranged at intervals along the second direction X, each support protrusion 142 extends along the third direction Y, and the side of each support protrusion 142 close to the electrode assembly 130 is an elliptical surface 1424, and the elliptical surface 1424 abuts against the electrode assembly 130.

[0050] It can be understood that since the plurality of support protrusions 142 are arranged at intervals along the second direction X, each support protrusion 142 extends along the third direction Y, and the side of each support protrusion 142 close to the electrode assembly 130 is an elliptical surface 1424 that abuts against the electrode assembly 130. At the same time, the orthographic projections of two adjacent support protrusions 142 along the second direction X on a plane perpendicular to the second direction X at least partially overlap, and thus can also provide good support for the electrode assembly 130.

[0051] As Figure 2 , Figure 12 and Figure 14 shown, further, a first reinforcing protrusion 143 located in the exhaust groove 141 is provided on the side of the end cap 140 close to the electrode assembly 130. The first reinforcing protrusion 143 and the support protrusion 142 are arranged at intervals, and the first reinforcing protrusion 143 is arranged along the circumferential direction of the explosion-proof valve 150.

[0052] It can be understood that when the battery cell 100 undergoes thermal runaway, there is a risk that the end cap 140 deforms under the influence of the internal pressure in the housing 110. In particular, the area where the explosion-proof valve 150 is located is the weak area of the end cap 140. By providing a first reinforcing protrusion 143 located in the exhaust groove 141 on the side of the end cap 140 close to the electrode assembly 130, and arranging the first reinforcing protrusion 143 along the circumferential direction of the explosion-proof valve 150, that is, the first reinforcing protrusion 143 is distributed around the explosion-proof valve 150, this can increase the structural strength of the end cap 140 at the position where the explosion-proof valve 150 is located, so as to reduce the risk of deformation of the end cap 140, thereby enhancing the safety of the battery cell 100.

[0053] As Figure 2 , Figure 12 and Figure 13 shown, further, the first reinforcing protrusion 143 is arranged around the explosion-proof valve 150. The vertical distance from the side of the first reinforcing protrusion 143 close to the electrode assembly 130 to the bottom wall of the exhaust groove 141 is H1, and the vertical distance from the side of each support protrusion 142 close to the electrode assembly 130 to the bottom wall of the exhaust groove 141 is H2, satisfying: H1 < H2; wherein, the units of both H1 and H2 are mm.

[0054] It can be understood that since the first reinforcing protrusion 143 is arranged around the explosion-proof valve 150, that is, the first reinforcing protrusion 143 is distributed around the explosion-proof valve 150 and is arranged in a ring shape, this can more effectively increase the structural strength of the end cap 140 at the position where the explosion-proof valve 150 is located; at the same time, since the vertical distance from the side of the first reinforcing protrusion 143 close to the electrode assembly 130 to the bottom wall of the exhaust groove 141 is H1 mm, and the vertical distance from the side of each support protrusion 142 close to the electrode assembly 130 to the bottom wall of the exhaust groove 141 is H2 mm, satisfying: H1 < H2, this can reduce the risk of the first reinforcing protrusion 143 hindering the gas from reaching the explosion-proof valve 150 from the exhaust groove 141, thereby reducing the possibility of a functional conflict between the first reinforcing protrusion 143 and the exhaust groove 141.

[0055] As Figure 12 and Figure 14 shown, further, a notch 144 penetrating through the first reinforcing protrusion 143 is provided on the first reinforcing protrusion 143, and the notch 144 is communicated with the exhaust groove 141, so that part of the gas flowing through the exhaust groove 141 can reach the explosion-proof valve 150 through the notch 144 and be discharged, further reducing the possibility of a functional conflict between the first reinforcing protrusion 143 and the exhaust groove 141.

[0056] It should be noted that the notch 144 penetrating the first reinforcing protrusion 143 means that the notch 144 penetrates the first reinforcing protrusion 143, and the penetration direction can be any direction. For example, the notch 144 penetrates the first reinforcing protrusion 143 along the second direction X, or penetrates the first reinforcing protrusion 143 along the third direction Y, or penetrates the first reinforcing protrusion 143 along other directions intersecting the second direction X and the third direction Y. No specific limitation is made here.

[0057] As Figure 3 and Figure 8 shown, in one embodiment, a plurality of grooves 145 are provided on the side of the end cap 140 away from the electrode assembly 130. Adjacent grooves 145 are arranged at intervals, and the grooves 145 and the exhaust groove 141 are arranged opposite to each other along the first direction Z.

[0058] It can be understood that by providing a plurality of grooves 145 on the side of the end cap 140 away from the electrode assembly 130, the weight of the end cap 140 can be reduced, thereby improving the energy density of the battery cell 100.

[0059] As Figure 7 and Figure 8 shown, further, each groove 145 and a support protrusion 142 are integrally formed by stamping, that is, the plurality of grooves 145 and the plurality of support protrusions 142 are in a one-to-one corresponding relationship of integral stamping. This can further enhance the structural strength of the end cap 140 and reduce the weight of the end cap 140, making the end cap 140 have the dual characteristics of high strength and light weight.

[0060] As Figure 8 and Figure 9 shown, further, a second reinforcing protrusion 146 is provided on the side of the end cap 140 away from the electrode assembly 130. The grooves 145 and the second reinforcing protrusion 146 are arranged at intervals. The second reinforcing protrusion 146 is located at the edge of the end cap 140 and surrounds the explosion-proof valve 150, and the second reinforcing protrusion 146 is connected to the housing 110.

[0061] It should be noted that the second reinforcing protrusion 146 surrounding the explosion-proof valve 150 means that the second reinforcing protrusion 146 is distributed around the explosion-proof valve 150 and is arranged in a ring shape.

[0062] It can be understood that by providing the second reinforcing protrusion 146, the connection strength between the end cap 140 and the housing 110 can be enhanced. Especially when the end cap 140 and the housing 110 are welded, the welding strength between the end cap 140 and the housing 110 can be increased, thereby reducing the possibility that the end cap 140 at the welding area is blown off and causing the battery cell 100 to explode.

[0063] As Figure 3As shown, in one embodiment, the battery cell 100 has a second direction X perpendicular to the first direction Z. A notch groove 147 is provided on a side of the end cap 140 away from the electrode assembly 130. The notch groove 147 and the explosion-proof valve 150 are arranged at intervals along the second direction X, and the notch groove 147 and the exhaust groove 141 are arranged opposite to each other along the first direction Z.

[0064] It can be understood that when the high-temperature and high-pressure gas generated by the thermal runaway of the battery cell 100 is large in quantity and high in rate, resulting in insufficient pressure relief by the explosion-proof valve 150, the notch groove 147 serves as a second weak area other than the explosion-proof valve 150 to open the valve for exhaust, which can assist the explosion-proof valve 150 in pressure relief, thereby further enhancing the safety of the battery cell 100.

[0065] It should be noted that in order to prioritize pressure relief through the explosion-proof valve 150, the bursting value of the end cap 140 at the position of the notch groove 147 is greater than the bursting value of the explosion-proof valve 150, that is, the pressure relief threshold at the notch groove 147 is greater than the pressure relief threshold of the explosion-proof valve 150; of course, it is also possible to prioritize pressure relief through the notch groove 147, or to perform pressure relief through the notch groove 147 and the explosion-proof valve 150 simultaneously, that is, the pressure relief threshold at the notch groove 147 is less than or equal to the pressure relief threshold of the explosion-proof valve 150, and the specific pressure relief thresholds of the two are not specifically limited herein.

[0066] As Figure 3 shown, further, the number of the notch grooves 147 is multiple, and the multiple notch grooves 147 are arranged at intervals along the second direction X. The notch groove 147 and the explosion-proof valve 150 are arranged at intervals along the second direction X.

[0067] It can be understood that by arranging multiple notch grooves 147 at intervals along the second direction X, the pressure relief efficiency can be increased, that is, it can cooperate with the explosion-proof valve 150 to discharge a large amount of high-temperature and high-pressure gas generated in the housing 110, thereby further enhancing the safety of the battery cell 100.

[0068] As Figure 6 shown, in a specific embodiment, the notch groove 147 is an annular groove 1471, such as an O-shaped groove, a 0-shaped groove, a D-shaped groove, etc. Of course, as Figure 11 shown, in another specific embodiment, the notch groove 147 can also be a non-annular groove 1472, such as a C-shaped groove, a U-shaped groove, a V-shaped groove, an M-shaped groove, etc., and the specific shape of the notch groove 147 is not specifically limited herein.

[0069] As Figures 1 to 3As shown, in one embodiment, the battery cell 100 further includes a first insulating member 160, a second insulating member 190, and an insulating layer 170. An installation hole 112 is provided on the housing 110. The installation hole 112 and the end cap 140 are oppositely arranged along the third direction Y. The pole posts 120 respectively pass through the installation hole 112 and the first insulating member 160. The electrode assembly 130 includes an electrode body 131 and a tab 132 connected to each other. The tab 132 is connected to the pole post 120. The first insulating member 160 is disposed inside the housing 110 and abuts against the electrode body 131, so that the side of the electrode body 131 close to the pole post 120 is insulated from the housing 110. The second insulating member 190 passes through the installation hole 112 and is respectively connected to the housing 110 and the pole post 120, so that the housing 110 and the pole post 120 are insulated from each other. The insulating layer 170 is disposed inside the housing 110 and wraps around the outside of the electrode body 131, so that the outer peripheral side of the electrode body 131 is insulated from the housing 110. Thereby, the risk of short circuit is reduced, and thus the safety of the battery cell 100 is improved.

[0070] Exemplarily, the material of the first insulating member 160 and / or the material of the second insulating member 190 is plastic, inorganic insulating material (such as ceramics, glass, mica, asbestos, quartz, etc.), organic insulating material (such as rubber, wood, etc.), synthetic polymer material (such as epoxy resin, polyurethane, silicone, etc.), etc., and no specific limitation is made here.

[0071] As Figure 2 and Figure 3 As shown, further, a first ventilation hole 171 communicating with the exhaust groove 141 is provided on the side of the insulating layer 170 close to the explosion-proof valve 150, so as to evacuate the high-temperature and high-pressure gas flowing between the insulating layer 170 and the electrode body 131 to the explosion-proof valve 150 through the first ventilation hole 171 for discharge.

[0072] Exemplarily, the insulating layer 170 can be a Mylar film (biaxially stretched polyester film made of polyethylene terephthalate), polypropylene film, polyethylene film, polyvinyl chloride film, polycarbonate film, etc., and no specific limitation is made here.

[0073] As Figure 2 and Figure 3 As shown, in one embodiment, the battery cell 100 further includes a protective layer 180. The protective layer 180 is connected to the side of the end cap 140 away from the electrode assembly 130 and can be separated from the end cap 140 under the impact of gas when the explosion-proof valve 150 opens for exhaust. The protective layer 180 and the explosion-proof valve 150 are oppositely arranged along the third direction Y. A second ventilation hole 181 is provided on the protective layer 180. The protective layer 180 can bear part of the adverse effects of the external environment on the explosion-proof valve 150, so as to reduce the risk of accidental opening of the explosion-proof valve 150.

[0074] It should be noted that, in the battery cell 100 provided in this embodiment, by way of example, the tab 132 includes a positive tab and a negative tab, the terminal 120 includes a positive terminal and a negative terminal. The positive terminal and the negative terminal respectively penetrate through the housing 110. The electrode body 131 includes a positive electrode plate, a negative electrode plate and a separator. The separator is disposed between the positive electrode plate and the negative electrode plate. The positive electrode plate, the negative electrode plate and the separator are formed into the electrode body 131 through a winding process or through a stacking process. The positive tab is connected to the positive electrode plate, the negative tab is connected to the negative electrode plate. The positive terminal is connected to the positive tab to serve as the positive electrode when connected to an external circuit, and the negative terminal is connected to the negative tab to serve as the negative electrode when connected to an external circuit, thereby facilitating the charging and discharging of the battery cell 100.

[0075] As Figure 15 shown, to solve the above technical problems, an embodiment of the present application further provides a battery pack, which includes a separator 200 and the battery cell 100 in any of the above embodiments. An end cap 140 is disposed on the separator 200 to support the battery cell 100 through the separator 200. At the same time, an exhaust hole 210 penetrating along the first direction Z is provided on the separator 200. The exhaust hole 210 and the explosion-proof valve 150 are disposed opposite to each other along the first direction Z, so that the high-temperature and high-pressure gas discharged through the explosion-proof valve 150 can be further discharged outside the battery pack.

[0076] As Figures 15 to 17 shown, in one embodiment, the end cap 140 and the housing 110 are welded to form a weld 148. The weld 148 is located on the inner peripheral side of the housing 110, and the separator 200 is connected to the weld 148.

[0077] It can be understood that when the weld 148 formed by welding between the end cap 140 and the housing 110 is located on the inner peripheral side of the housing 110, by connecting the separator 200 to the weld 148, a binding force along the first direction Z can be applied to the weld 148, so that the area where the weld 148 is located can withstand a greater internal pressure of the housing 110.

[0078] As Figures 18 to 20 shown, in another embodiment, the end cap 140 and the housing 110 are welded to form a weld 148. The weld 148 is located on the outer peripheral side of the housing 110. A convex structure 300 is provided on a side of the separator 200 close to the end cap 140. The vertical distance from a side of the convex structure 300 close to the terminal 120 to the separator 200 is H3 mm, and the vertical distance from a side of the weld 148 close to the terminal 120 to the separator 200 is H4 mm, satisfying: H3 > H4. The convex structure 300 is connected to the weld 148.

[0079] It can be understood that when the weld seam 148 formed by welding between the end cover 140 and the housing 110 is located on the outer peripheral side of the housing 110, by connecting the raised structure 300 with a height higher than the weld seam 148 to the weld seam 148, a binding force perpendicular to the first direction Z can be exerted on the weld seam 148, so that the area where the weld seam 148 is located can withstand a greater internal pressure of the housing 110.

[0080] It should be noted that the connection between the partition 200 and the weld seam 148 and / or the connection between the raised structure 300 and the weld seam 148 can be abutting, bonding, welding, screw connection, etc., or can be connected through an elastic member (such as polyurethane, silica gel, rubber, etc. for the elastic member), that is, the elastic member is arranged between the partition 200 and the weld seam 148 / the elastic member is arranged between the raised structure 300 and the weld seam 148, and no specific limitation is made here.

[0081] As Figure 21 shown, further, the battery cell 100 has a third direction Y perpendicular to the first direction Z, the raised structure 300 has a plurality of positioning holes 310, the number of exhaust holes 210 and the number of battery cells 100 are both plural, the plurality of positioning holes 310 and the plurality of exhaust holes 210 are both arranged at intervals along the third direction Y, each positioning hole 310 and an exhaust hole 210 are arranged opposite to each other and communicated along the first direction Z, and each battery cell 100 passes through a positioning hole 310.

[0082] It should be noted that each positioning hole 310 and an exhaust hole 210 are arranged opposite to each other and communicated along the first direction Z, and each battery cell 100 passes through a positioning hole 310 means that: the plurality of positioning holes 310 and the plurality of exhaust holes 210 are arranged in one-to-one correspondence, and the plurality of battery cells 100 and the plurality of positioning holes 310 are arranged in one-to-one correspondence.

[0083] It can be understood that through the plurality of positioning holes 310 formed on the raised structure 300, each battery cell 100 passes through a positioning hole 310 to realize respectively clamping the plurality of battery cells 100 on the raised structure 300. In this way, it is convenient to position the battery cells 100 when assembling them to the partition 200, so as to improve the assembly efficiency, and the movement of the battery cells 100 relative to the partition 200 in the direction perpendicular to the first direction Z can be limited. At the same time, the raised structure 300 is also connected to the weld seam 148 and can exert a binding force on the weld seam 148, that is, the raised structure 300 has the dual functions of facilitating the assembly of the battery cells 100 and enhancing the structural strength of the area where the weld seam 148 is located.

[0084] It should be noted that since the battery pack provided in this embodiment has the battery cell 100 in any of the above embodiments, it has all the beneficial effects of the battery cell 100, and will not be elaborated here one by one.

[0085] In the description of this specification, the descriptions referring to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples", etc. mean that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of this application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0086] Although the embodiments of this application have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting this application. Those of ordinary skill in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of this application.

Claims

1. A battery cell, characterized in that, having a first direction (Z) and comprising: a housing (110), which is an integrally formed structure and has an opening (111); a terminal post (120) passing through the housing (110); an electrode assembly (130) disposed within the housing (110) and electrically connected to the terminal post (120); an end cap (140) connected to the housing (110) to seal the opening (111), the end cap (140) and the terminal post (120) being oppositely disposed along the first direction (Z), and an exhaust groove (141) being provided on a side of the end cap (140) close to the electrode assembly (130); an explosion-proof valve (150) disposed on the end cap (140), the explosion-proof valve (150) and the exhaust groove (141) being oppositely disposed along the first direction (Z).

2. The battery cell according to claim 1, characterized in that, A plurality of support protrusions (142) are provided on a side of the end cap (140) close to the electrode assembly (130), the plurality of support protrusions (142) being spaced apart and disposed within the exhaust groove (141), the support protrusions (142) and the explosion-proof valve (150) being spaced apart, and the support protrusions (142) abutting against the electrode assembly (130).

3. The battery cell according to claim 2, characterized in that, The battery cell has a second direction (X) perpendicular to the first direction (Z), and the positive projections of two adjacent support protrusions (142) along the second direction (X) on a plane perpendicular to the second direction (X) at least partially overlap.

4. The battery cell according to claim 3, characterized in that, The plurality of support protrusions (142) are connected to the side wall of the exhaust groove (141), each support protrusion (142) extending along a direction close to the explosion-proof valve (150), and a side of each support protrusion (142) close to the electrode assembly (130) being an arc surface (1421), the arc surface (1421) abutting against the electrode assembly (130).

5. The battery cell according to claim 3, characterized in that, A part of the plurality of support protrusions (142) are connected to the bottom wall of the exhaust groove (141), and a side of this part of the support protrusions (142) close to the electrode assembly (130) being a circular surface (1422), the circular surface (1422) abutting against the electrode assembly (130); another part of the plurality of support protrusions (142) are connected to the side wall of the exhaust groove (141), and a side of this part of the support protrusions (142) close to the electrode assembly (130) being a semi-circular surface (1423), the semi-circular surface (1423) abutting against the electrode assembly (130).

6. The battery cell according to claim 3, wherein The battery cell has a third direction (Y) that is perpendicular to the first direction (Z) and the second direction (X) pairwise. A plurality of the support protrusions (142) are arranged at intervals along the second direction (X). Each of the support protrusions (142) extends along the third direction (Y). And on the side of each support protrusion (142) close to the electrode assembly (130) is an oval surface (1424), and the oval surface (1424) abuts against the electrode assembly (130).

7. The battery cell according to claim 2, characterized in that, On the side of the end cap (140) close to the electrode assembly (130), a first reinforcing protrusion (143) is provided in the exhaust groove (141). The first reinforcing protrusion (143) and the support protrusion (142) are arranged at intervals. The first reinforcing protrusion (143) is arranged along the circumference of the explosion-proof valve (150).

8. The battery cell according to claim 7, characterized in that, The first reinforcing protrusion (143) surrounds the explosion-proof valve (150). The vertical distance from the side of the first reinforcing protrusion (143) close to the electrode assembly (130) to the bottom wall of the exhaust groove (141) is H1 mm. The vertical distance from the side of each support protrusion (142) close to the electrode assembly (130) to the bottom wall of the exhaust groove (141) is H2 mm, and it satisfies: H1 < H2.

9. The battery cell according to claim 8, characterized in that, A notch (144) penetrating through it is provided on the first reinforcing protrusion (143), and the notch (144) communicates with the exhaust groove (141).

10. The battery cell according to claim 1, wherein, On the side of the end cap (140) away from the electrode assembly (130), a plurality of grooves (145) are provided. Adjacent two of the grooves (145) are arranged at intervals. The grooves (145) and the exhaust groove (141) are arranged opposite to each other along the first direction (Z).

11. The battery cell according to claim 10, characterized in that, On the side of the end cap (140) away from the electrode assembly (130), a second reinforcing protrusion (146) is provided. The grooves (145) and the second reinforcing protrusion (146) are arranged at intervals. The second reinforcing protrusion (146) is located at the edge of the end cap (140) and surrounds the explosion-proof valve (150), and the second reinforcing protrusion (146) is connected to the housing (110).

12. The battery cell according to claim 1, wherein, The battery cell has a second direction (X) perpendicular to the first direction (Z). On the side of the end cap (140) away from the electrode assembly (130), a scoring groove (147) is provided. The scoring groove (147) and the explosion-proof valve (150) are arranged at intervals along the second direction (X). The scoring groove (147) and the exhaust groove (141) are arranged opposite to each other along the first direction (Z).

13. The battery cell according to claim 12, characterized in that, The number of the scoring grooves (147) is multiple. A plurality of the scoring grooves (147) are arranged at intervals along the second direction (X). The scoring groove (147) and the explosion-proof valve (150) are arranged at intervals along the second direction (X).

14. A battery pack, characterized in that, Comprising a separator (200) and a battery cell as recited in any one of claims 1 to 13, the end cap (140) is disposed on the separator (200), an exhaust hole (210) penetrating along the first direction (Z) is provided on the separator (200), and the exhaust hole (210) and the explosion-proof valve (150) are oppositely disposed along the first direction (Z).

15. The battery pack according to claim 14, wherein, The end cap (140) and the housing (110) are welded to form a weld seam (148), the weld seam (148) is located on the inner peripheral side of the housing (110), and the separator (200) is connected to the weld seam (148).

16. The battery pack according to claim 14, wherein, The end cap (140) and the housing (110) are welded to form a weld seam (148), the weld seam (148) is located on the outer peripheral side of the housing (110), a convex structure (300) is provided on a side of the separator (200) close to the end cap (140), a perpendicular distance from a side of the convex structure (300) close to the pole column (120) to the separator (200) is H3 mm, a perpendicular distance from a side of the weld seam (148) close to the pole column (120) to the separator (200) is H4 mm, satisfying: H3 > H4, and the convex structure (300) is connected to the weld seam (148).

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