Battery cell and battery pack

Abstract

The application provides a battery monomer and a battery pack, and relates to the technical field of batteries. The battery monomer comprises a shell with an opening, a pole provided in the shell, an electrode assembly provided in the shell and electrically connected with the pole, an end cover connected with the shell to cover the opening, and an explosion-proof valve provided on the end cover. The shell is an integral molding structure, the end cover and the pole are oppositely arranged along a first direction, one side of the end cover close to the electrode assembly is provided with an exhaust groove, and the explosion-proof valve and the exhaust groove are oppositely arranged along the first direction. In the battery monomer provided by the application, the position of the pole is no longer a weak area of the shell, so that the shell has higher structural strength at the position, thereby being able to resist greater internal pressure of the shell; the exhaust groove on the end cover facilitates the dispersion of high-temperature and high-pressure gas in the shell to the explosion-proof valve 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 field of battery technology, and in particular to a battery cell and a battery pack. Background Technology

[0002] The battery cell is a crucial component of the battery pack. To mitigate the risk of dual failures—electrical insulation and thermal runaway—battery cells typically employ a thermoelectric separation design, placing the terminals on end caps at the opening of the casing and mounting explosion-proof valves on the casing itself. However, when a battery cell experiences thermal runaway, some of the gas inside the casing tends to accumulate towards the terminals under heat. Due to the opening, the connection area between the end cap and the casing opening becomes a weak point. As the internal pressure continues to rise, the high-pressure gas can force the end cap off, causing the battery cell to explode and compromising its safety. Utility Model Content

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

[0004] To achieve the above objectives, the technical solution adopted in this application is as follows:

[0005] In a first aspect, embodiments of this application provide a battery cell having a first orientation and comprising:

[0006] The shell is a one-piece molded structure and has an opening;

[0007] The pole is inserted into the housing;

[0008] An electrode assembly is disposed within the housing and electrically connected to the electrode post;

[0009] An end cap is connected to the housing to seal the opening. The end cap and the electrode post are arranged opposite to each other along the first direction. An exhaust groove is provided on the side of the end cap near the electrode assembly.

[0010] An explosion-proof valve is disposed on the end cap, and the explosion-proof valve and the exhaust channel are disposed opposite to each other along the first direction.

[0011] In one embodiment of the first aspect, the end cap is provided with a plurality of support protrusions on the side near the electrode assembly, the plurality of support protrusions are spaced apart in the vent groove, the support protrusions are spaced apart from the explosion-proof valve, and the support protrusions abut against the electrode assembly.

[0012] In one embodiment of the first aspect, the battery cell has a second direction perpendicular to the first direction, and the orthographic projections of two adjacent support protrusions along the second direction at least partially overlap on a plane perpendicular to the second direction.

[0013] In one embodiment of the first aspect, a plurality of the support protrusions are connected to the sidewall of the exhaust channel, each of the support protrusions extends in a direction close to the explosion-proof valve, and the side of each support protrusion close to the electrode assembly is an arc-shaped surface, the arc-shaped surface abutting against the electrode assembly.

[0014] In one embodiment of the first aspect, a portion of the plurality of support protrusions is connected to the bottom wall of the exhaust groove, and the side of this portion of the support protrusions near the electrode assembly is a circular surface, which abuts against the electrode assembly; another portion of the plurality of support protrusions is connected to the side wall of the exhaust groove, and the side of this portion of the support protrusions near the electrode assembly is a semi-circular surface, which abuts against the electrode assembly.

[0015] In one embodiment of the first aspect, the battery cell has a third direction that is mutually perpendicular to both the first direction and the second direction, a plurality of support protrusions are spaced apart along the second direction, each support protrusion extends along the third direction, and the side of each support protrusion near the electrode assembly is an elliptical surface, the elliptical surface abutting against the electrode assembly.

[0016] In one embodiment of the first aspect, the end cap is provided with a first reinforcing protrusion located in the vent groove on the side near the electrode assembly, the first reinforcing protrusion and the support protrusion being spaced apart, and the first reinforcing protrusion being arranged circumferentially along the explosion-proof valve.

[0017] In one embodiment of the first aspect, the first reinforcing protrusion is arranged around the explosion-proof valve, the vertical distance from the side of the first reinforcing protrusion near the electrode assembly to the bottom wall of the exhaust groove is H1 mm, and the vertical distance from the side of each of the supporting protrusions near the electrode assembly to the bottom wall of the exhaust groove is H2 mm, satisfying: H1 < H2.

[0018] In one embodiment of the first aspect, the first reinforcing protrusion is provided with a through notch that communicates with the exhaust groove.

[0019] In one embodiment of the first aspect, the end cap is provided with a plurality of grooves on the side away from the electrode assembly, with adjacent grooves spaced apart, and the grooves and the venting grooves are arranged opposite to each other along the first direction.

[0020] In one embodiment of the first aspect, a second reinforcing protrusion is provided on the side of the end cap away from the electrode assembly, the groove and the second reinforcing protrusion are spaced apart, the second reinforcing protrusion is located at the edge of the end cap and surrounds the explosion-proof valve, and the second reinforcing protrusion is connected to the housing.

[0021] In one embodiment of the first aspect, the battery cell has a second direction perpendicular to the first direction, the end cap is provided with a groove on the side away from the electrode assembly, the groove and the explosion-proof valve are spaced apart along the second direction, and the groove and the vent groove are arranged opposite to each other along the first direction.

[0022] In one embodiment of the first aspect, the number of the grooves is plurality, and the plurality of grooves are spaced apart along the second direction, the grooves and the explosion-proof valve being spaced apart along the second direction. In a second aspect, embodiments of this application provide a battery pack, including a separator as described in any embodiment of the first aspect, a battery cell, an end cap disposed on the separator, and a vent hole penetrating along the first direction on the separator, the vent hole and the explosion-proof valve being disposed opposite each other along the first direction.

[0023] In one embodiment of the second aspect, the end cap is welded to the housing to form a weld, the weld being located on the inner circumferential side of the housing, and the partition is connected to the weld.

[0024] In one embodiment of the second aspect, the end cap is welded to the housing to form a weld, the weld is located on the outer periphery of the housing, and the partition is provided with a protruding structure on the side near the end cap. The vertical distance from the side of the protruding structure near the pole post to the partition is H3mm, and the vertical distance from the side of the weld near the pole post to the partition is H4mm, satisfying: H3>H4, and the protruding structure is connected to the weld.

[0025] The beneficial effects of this application are as follows:

[0026] The battery cell provided in this application features a one-piece molded casing. The end cap is connected to the casing to seal the opening, and an explosion-proof valve is located on the end cap. The terminals penetrate the casing, and the end cap and terminals are positioned opposite each other along a first direction. This achieves thermal and electrical separation, and the location of the terminals is no longer a weak point in the casing, resulting in higher structural strength and the ability to withstand greater internal pressure. Furthermore, a venting groove is provided on the side of the end cap near the electrode assembly, and the venting groove and explosion-proof valve are positioned opposite each other along the first direction. This facilitates the dissipation of high-temperature, high-pressure gases from within the casing to the explosion-proof valve, reducing internal pressure. Therefore, the safety of the battery cell is improved.

[0027] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0028] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0029] Figure 1 A three-dimensional structural schematic diagram of a battery cell in one embodiment of this application is shown;

[0030] Figure 2 It shows Figure 1 Decomposition structure diagram Figure 1 ;

[0031] Figure 3 It shows Figure 1 Decomposition structure diagram Figure 2 ;

[0032] Figure 4 It shows Figure 2 A three-dimensional structural diagram of the middle end cap;

[0033] Figure 5 It shows Figure 2 A schematic diagram of the structure of the middle end cap from one perspective;

[0034] Figure 6 It shows Figure 2 Another structural diagram of the middle end cap;

[0035] Figure 7 A three-dimensional structural diagram of the end cap of a battery cell is shown in another embodiment of this application. Figure 1 ;

[0036] Figure 8 A three-dimensional structural diagram of the end cap of a battery cell is shown in another embodiment of this application. Figure 2 ;

[0037] Figure 9 It shows Figure 8 Enlarged structural diagram of region A in the middle;

[0038] Figure 10 This illustration shows a schematic diagram of the end cap structure of a battery cell in another embodiment of this application.

[0039] Figure 11This illustration shows a schematic diagram of the end cap of a battery cell from another perspective in another embodiment of this application;

[0040] Figure 12 A three-dimensional structural schematic diagram of the end cap of a battery cell in another embodiment of this application is shown;

[0041] Figure 13 It shows Figure 12 A magnified structural diagram of region B in the middle;

[0042] Figure 14 This shows a schematic diagram of the end cap of a battery cell from one perspective in yet another embodiment of this application;

[0043] Figure 15 This illustration shows a schematic diagram of the assembly structure of the battery cell and separator of a battery pack in one embodiment of this application;

[0044] Figure 16 It shows Figure 14 A schematic diagram of the cross-sectional structure at the CC section;

[0045] Figure 17 It shows Figure 15 A magnified structural diagram of region D in the middle;

[0046] Figure 18 This invention provides a schematic diagram of the assembly structure of the battery cell, separator, and protrusion structure of the battery pack in another embodiment of the present application.

[0047] Figure 19 It shows Figure 17 Schematic diagram of the cross-sectional structure at the middle EE;

[0048] Figure 20 It shows Figure 18 A magnified structural diagram of region F in the middle;

[0049] Figure 21 An exploded structural diagram of multiple battery cells, separators, and protrusions of a battery pack in another embodiment of this application is shown.

[0050] Explanation of key component symbols:

[0051] 100 - Battery cell; 110 - Housing; 111 - Opening; 112 - Mounting hole; 120 - Terminal post; 130 - Electrode assembly; 131 - Electrode body; 132 - Tab; 140 - End cap; 141 - Vent groove; 142 - Support protrusion; 1421 - Arc-shaped surface; 1422 - Circular surface; 1423 - Semi-circular surface; 1424 - Elliptical surface; 143 - First reinforcing protrusion; 144 - Notch; 145 - Groove; 146 - Second Reinforcing protrusion; 147-groove; 1471-annular groove; 1472-non-annular groove; 148-weld; 150-explosion-proof valve; 160-first insulating component; 170-insulating layer; 171-first vent; 180-protective layer; 181-second vent; 190-second insulating component; 200-partition; 210-vent hole; 300-protruding structure; 310-positioning hole; Z-first direction; X-second direction; Y-third direction. Detailed Implementation

[0052] The embodiments of this application are described in detail below. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application.

[0053] In the description of this application, the terms "center", "longitudinal", "lateral", "length", "width", "height", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0054] Furthermore, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first and second features are in direct contact, or that they are in indirect contact through an intermediate medium. Moreover, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0055] In the description of this application, the terms "first," "second," etc., are used to distinguish different objects and should not be construed as indicating or implying a specific order or hierarchy, or implicitly specifying the number of technical features indicated. Therefore, a feature marked "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly defined.

[0056] In the description of this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0057] In the description of this application, the term "and / or" indicates that three relationships can exist. For example, A and / or B can represent three cases: A alone, A and B simultaneously, and B alone. Additionally, the character " / " generally indicates that the preceding and following objects have an "or" relationship.

[0058] In the description of this application, "parallel" includes not only the case of absolute parallelism, but also the case of approximate parallelism as commonly understood in engineering; similarly, "perpendicular" also includes not only the case of absolute perpendicularity, but also the case of approximate perpendicularity as commonly understood in engineering. For example, if the angle between two directions is 80° to 90°, the two directions can be considered perpendicular; if the angle between two directions is 0° to 10°, the two directions can be considered parallel.

[0059] The battery cell is a crucial component of the battery pack. To mitigate the risk of dual failures—electrical insulation and thermal runaway—the battery cell typically employs a thermoelectric separation design. This means that the terminals are positioned on end caps at the opening of the casing, and the explosion-proof valve is located on the casing itself. However, when a battery cell experiences thermal runaway, some of the gas inside the casing tends to accumulate towards the terminals under heat. Since the casing has an opening that is welded to the end cap, the connection area between the end cap and the casing opening becomes a weak point. As the internal pressure of the casing continues to rise, the high-pressure gas can force the end cap off, causing the battery cell to explode and compromising its safety.

[0060] like Figure 1As shown, to solve the above-mentioned technical problems, embodiments of this application provide a battery cell 100, which relates to the field of battery technology and is mainly used in battery packs, so as to be indirectly used in electrical devices or energy storage devices in the form of battery packs. Of course, the battery cell 100 can also be directly used in electrical devices or energy storage devices without taking the form of a battery pack, and no specific limitation is made to the application scenarios of the battery cell 100 here.

[0061] For example, electrical devices can be vehicles, mobile phones, portable devices, laptops, ships, spacecraft, electric toys, and power tools. Vehicles can be gasoline-powered cars, natural gas-powered cars, new energy vehicles, etc., and new energy vehicles can be pure electric vehicles, hybrid electric vehicles, and range-extended electric vehicles, etc.; spacecraft can be airplanes, rockets, space shuttles, drones, and spacecraft, etc.; electric toys include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc.; power tools can be metal cutting power tools, grinding power tools, assembly power tools, and railway power tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, and electric planers, etc.; energy storage devices include energy storage containers, energy storage power stations, etc.; no specific limitations are made on the types of electrical devices and energy storage devices here.

[0062] like Figures 1 to 3 As shown, the battery cell 100 provided in this embodiment has a first direction Z and includes: a housing 110, a terminal post 120, an electrode assembly 130, an end cap 140, and an explosion-proof valve 150.

[0063] The housing 110 is an integrally formed structure and has an opening 111; the electrode post 120 passes through the housing 110; the electrode assembly 130 is disposed inside the housing 110 and is electrically connected to the electrode post 120; the end cap 140 is connected to the housing 110 to seal the opening 111, the end cap 140 and the electrode post 120 are arranged opposite each other along the first direction Z, and the end cap 140 is provided with an exhaust groove 141 on the side near 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 arranged opposite each other along the first direction Z.

[0064] It should be noted that the housing 110 is a one-piece molded structure, which means that the housing 110 is a structure made by a one-piece molding process, such as stamping, injection molding, die casting, extrusion molding, blow molding, 3D printing, etc. The opening 111 formed on the housing 110 made by the one-piece molding 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 sealed space is formed inside the housing 110 to encapsulate the electrode assembly 130.

[0065] For example, the connection between the end cap 140 and the housing 110 can be welding, snap-fitting, bonding, screw connection, roll forming connection, etc., without specific limitations.

[0066] It is understood that the battery cell 100 provided in this embodiment has a one-piece molded housing 110. 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, and the terminal post 120 passes through the housing 110. The end cap 140 and the terminal post 120 are arranged opposite each other along the first direction Z. This also achieves thermal and electrical separation, and the location of the terminal post 120 is no longer a weak area of ​​the housing 110, giving the housing 110 higher structural strength at that location, thereby being able to withstand greater internal pressure. At the same time, since the end cap 140 has an exhaust groove 141 on the side near the electrode assembly 130, and the exhaust groove 141 and the explosion-proof valve 150 are arranged opposite each other along the first direction Z, it is convenient to disperse the high-temperature and high-pressure gas inside the housing 110 to the explosion-proof valve 150 to reduce the internal pressure of the housing 110. Thus, the safety of the battery cell 100 is improved.

[0067] like Figure 2 As shown, in one embodiment, the end cap 140 is provided with a plurality of support protrusions 142 on the side near the electrode assembly 130. The plurality of support protrusions 142 are spaced apart in the vent groove 141. The support protrusions 142 and the explosion-proof valve 150 are spaced apart. The support protrusions 142 abut against the electrode assembly 130.

[0068] Understandably, since multiple support protrusions 142 are provided on the side of the end cap 140 near the electrode assembly 130, and the multiple support protrusions 142 abut against the electrode assembly 130 respectively to support the electrode assembly 130, this not only increases the stability of the electrode assembly 130, but also reduces the possibility that the venting groove 141 will be blocked by the electrode assembly 130 when the battery cell 100 experiences thermal runaway or is subjected to external impact, thereby improving the safety of the battery cell 100.

[0069] like Figure 2 , Figure 5 , Figure 10 and Figure 14 As shown, the battery cell 100 further has a second direction X perpendicular to the first direction Z, and the orthographic projections of two adjacent support protrusions 142 along the second direction X on the plane perpendicular to the second direction X at least partially overlap, so that the combination of multiple support protrusions 142 can provide better support for the electrode assembly 130.

[0070] It should be noted that the orthographic projections of two adjacent support protrusions 142 along the second direction X onto a plane perpendicular to the second direction X at least partially overlap, including: Figure 5 and Figure 10 The examples shown only partially overlap, and Figure 14 The examples shown are of two cases of complete overlap; no specific restrictions are placed on the type of overlap.

[0071] It should be noted that the plane perpendicular to the second direction X can be the wall of the housing 110 along the second direction X. Of course, the plane perpendicular to the second direction X can also be the wall of the end cap 140 along the second direction X. No specific limitation is made on the plane here.

[0072] like Figure 2 , Figure 4 and Figure 5 As shown, in a specific embodiment, a plurality of support protrusions 142 are connected to the sidewall of the exhaust groove 141. Each support protrusion 142 extends in 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-shaped surface 1421, which abuts against the electrode assembly 130.

[0073] Understandably, since multiple support protrusions 142 are connected to the sidewall of the exhaust channel 141, i.e., the multiple support protrusions 142 are located on the sidewall of the exhaust channel 141, and each support protrusion 142 extends along the direction close to the explosion-proof valve 150, the included angle α formed between the side of each support protrusion 142 near the explosion-proof valve 150 and the sidewall of the exhaust channel 141 is an acute angle (i.e., 0° < α < 90°). This reduces the flow resistance of the gas and guides 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 support protrusions 142 along the second direction X on the plane perpendicular to the second direction X at least partially overlap, and the side of each support protrusion 142 near the electrode assembly 130 is an arc-shaped surface 1421 that abuts against the electrode assembly 130, this better supports the electrode assembly 130.

[0074] For example, α can be any value other than 0° and 90°, such as any one or any range between any two of the following: 1°, 2°, 5°, 8°, 10°, 15°, 18°, 20°, 25°, 30°, 38°, 40°, 45°, 50°, 55°, 60°, 64°, 70°, 80°, and 89°, without any specific limitation here.

[0075] like Figure 7 , Figure 8 and Figure 10As shown, in another specific embodiment, a portion of the plurality of support protrusions 142 are connected to the bottom wall of the exhaust groove 141, and the side of this portion of the support protrusion 142 near the electrode assembly 130 is a circular surface 1422, which abuts against the electrode assembly 130; another portion of the plurality of support protrusions 142 are connected to the side wall of the exhaust groove 141, and the side of this portion of the support protrusion 142 near the electrode assembly 130 is a semi-circular surface 1423, which abuts against the electrode assembly 130.

[0076] It is understandable that, since a portion of the multiple support protrusions 142 are connected to the bottom wall of the exhaust groove 141, and the side of this portion of the support protrusion 142 near the electrode assembly 130 is a circular surface 1422 that abuts against the electrode assembly 130, that is, this portion of the support protrusion 142 at the bottom wall position of the exhaust groove 141 has a circular surface 1422, and another portion of the multiple support protrusions 142 are connected to the side wall of the exhaust groove 141, and the side of this portion of the support protrusion 142 near the electrode assembly 130 is a semi-circular surface 1423 that abuts against the electrode assembly 130, that is, this portion of the support protrusion 142 at the side wall position of the exhaust groove 141 has a semi-circular surface 1423, and 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, thus also providing good support for the electrode assembly 130.

[0077] like Figure 12 , Figure 13 and Figure 14 As shown, in another specific embodiment, the battery cell 100 has a third direction Y that is mutually perpendicular to 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 mutually perpendicular to each other). A plurality of support protrusions 142 are spaced apart along the second direction X. Each support protrusion 142 extends along the third direction Y, and the side of each support protrusion 142 near the electrode assembly 130 is an elliptical surface 1424, which abuts against the electrode assembly 130.

[0078] It is understandable that since multiple support protrusions 142 are spaced apart along the second direction X, each support protrusion 142 extends along the third direction Y, and the side of each support protrusion 142 near the electrode assembly 130 is an elliptical surface 1424 that abuts against the electrode assembly 130, and 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, thus providing good support for the electrode assembly 130.

[0079] like Figure 2 , Figure 12 and Figure 14As shown, the end cap 140 is further provided with a first reinforcing protrusion 143 located in the exhaust groove 141 on the side near the electrode assembly 130. The first reinforcing protrusion 143 and the support protrusion 142 are spaced apart. The first reinforcing protrusion 143 is arranged along the circumference of the explosion-proof valve 150.

[0080] It is understandable that when the battery cell 100 experiences thermal runaway, the end cap 140 is at risk of deformation due to the internal pressure of the housing 110, especially since the area where the explosion-proof valve 150 is located is a weak point of the end cap 140. By providing a first reinforcing protrusion 143 located in the vent groove 141 on the side of the end cap 140 near the electrode assembly 130, and by making the first reinforcing protrusion 143 arranged circumferentially around the explosion-proof valve 150, that is, the first reinforcing protrusion 143 is distributed around the explosion-proof valve 150, the structural strength of the end cap 140 at the location of the explosion-proof valve 150 can be increased, thereby reducing the risk of deformation of the end cap 140 and improving the safety of the battery cell 100.

[0081] like Figure 2 , Figure 12 and Figure 13 As 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 near the electrode assembly 130 to the bottom wall of the exhaust groove 141 is H1, and the vertical distance from the side of each supporting protrusion 142 near the electrode assembly 130 to the bottom wall of the exhaust groove 141 is H2, satisfying: H1 < H2; where the units of H1 and H2 are both mm.

[0082] Understandably, 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 arranged in a ring, this can more effectively increase the structural strength of the end cap 140 at the location of the explosion-proof valve 150. At the same time, since the vertical distance from the side of the first reinforcing protrusion 143 near the electrode assembly 130 to the bottom wall of the exhaust groove 141 is H1mm, and the vertical distance from the side of each support protrusion 142 near the electrode assembly 130 to the bottom wall of the exhaust groove 141 is H2mm, satisfying: H1 < H2, this can reduce the risk of gas being obstructed from reaching the explosion-proof valve 150 from the exhaust groove 141 due to the arrangement of the first reinforcing protrusion 143, thereby reducing the possibility of functional conflict between the first reinforcing protrusion 143 and the exhaust groove 141.

[0083] like Figure 12 and Figure 14As shown, the first reinforcing protrusion 143 is further provided with a through notch 144, which is connected to the exhaust groove 141, so that some 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 functional conflict between the first reinforcing protrusion 143 and the exhaust groove 141.

[0084] It should be noted that the notch 144 provided on the first reinforcing protrusion 143 means that the notch 144 penetrates the first reinforcing protrusion 143, and the direction of penetration can be any direction. For example, the notch 144 can penetrate the first reinforcing protrusion 143 along the second direction X, or along the third direction Y, or along other directions that intersect the second direction X and the third direction Y. No specific limitation is made here.

[0085] like Figure 3 and Figure 8 As shown, in one embodiment, the end cap 140 is provided with a plurality of grooves 145 on the side away from the electrode assembly 130, with adjacent grooves 145 spaced apart, and the grooves 145 and the vent grooves 141 are arranged opposite to each other along the first direction Z.

[0086] It is understandable that by providing multiple 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 increasing the energy density of the battery cell 100.

[0087] like Figure 7 and Figure 8 As shown, each groove 145 is integrally stamped with a support protrusion 142, that is, the multiple grooves 145 and the multiple support protrusions 142 are integrally stamped in a one-to-one correspondence. This can further enhance the structural strength of the end cap 140 and reduce the weight of the end cap 140, so that the end cap 140 has both high strength and light weight.

[0088] like Figure 8 and Figure 9 As shown, the end cap 140 is further provided with a second reinforcing protrusion 146 on the side away from the electrode assembly 130. The groove 145 and the second reinforcing protrusion 146 are spaced apart. The second reinforcing protrusion 146 is located at the edge of the end cap 140 and surrounds the explosion-proof valve 150. The second reinforcing protrusion 146 is connected to the housing 110.

[0089] 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.

[0090] Understandably, by setting the second reinforcing protrusion 146, the strength of the connection between the end cap 140 and the housing 110 can be enhanced. In particular, when the end cap 140 is welded to the housing 110, the welding strength between the end cap 140 and the housing 110 can be increased, thereby reducing the possibility that the end cap 140 in the welding area will be blown away and cause the battery cell 100 to explode.

[0091] like Figure 3 As shown, in one embodiment, the battery cell 100 has a second direction X perpendicular to the first direction Z, and the end cap 140 is provided with a groove 147 on the side away from the electrode assembly 130. The groove 147 and the explosion-proof valve 150 are spaced apart along the second direction X, and the groove 147 and the venting groove 141 are arranged opposite to each other along the first direction Z.

[0092] It is understandable that when the battery cell 100 experiences thermal runaway, generating a large amount of high-temperature and high-pressure gas at a high velocity, which makes the explosion-proof valve 150 insufficient to relieve pressure, the groove 147 is used as the second weak point besides the explosion-proof valve 150 to open the valve and release gas, which can assist the explosion-proof valve 150 in relieving pressure, thereby further improving the safety of the battery cell 100.

[0093] It should be noted that, in order to prioritize pressure relief through the explosion-proof valve 150, the burst value of the end cap 140 at the groove 147 is greater than that of the explosion-proof valve 150, that is, the pressure relief threshold at the groove 147 is greater than the pressure relief threshold of the explosion-proof valve 150; of course, pressure relief can also be prioritized through the groove 147, or pressure relief can be carried out simultaneously through the groove 147 and the explosion-proof valve 150, that is, the pressure relief threshold at the groove 147 is less than or equal to the pressure relief threshold of the explosion-proof valve 150. Here, no specific limit is made on the pressure relief thresholds of the two.

[0094] like Figure 3 As shown, further, there are multiple grooves 147, and the multiple grooves 147 are spaced apart along the second direction X. The grooves 147 and the explosion-proof valve 150 are spaced apart along the second direction X.

[0095] It is understandable that by setting multiple grooves 147 at intervals along the second direction X, the efficiency of pressure relief can be increased, that is, it can work with the explosion-proof valve 150 to discharge a large amount of high-temperature and high-pressure gas generated inside the casing 110, thereby further improving the safety of the battery cell 100.

[0096] like Figure 6 As shown, in a specific embodiment, the notched groove 147 is an annular groove 1471, such as an O-ring, a D-ring, etc. Of course, as... Figure 11As shown, in another specific embodiment, the 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. The shape of the groove 147 is not specifically limited here.

[0097] like Figures 1 to 3 As 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. A mounting hole 112 is provided on the housing 110. The mounting hole 112 and the end cap 140 are arranged opposite each other along a third direction Y. The electrode posts 120 are respectively disposed through the mounting hole 112 and the first insulating member 160. The electrode assembly 130 includes a connected electrode body 131 and an electrode tab 132. The electrode tab 132 is connected to the electrode post 120. The first insulating member 160... The electrode body 131 is disposed within the housing 110 and abuts against the electrode body 131, thereby insulating the side of the electrode body 131 near the terminal post 120 from the housing 110. A second insulating member 190 passes through the mounting hole 112 and is connected to both the housing 110 and the terminal post 120, thereby insulating the housing 110 and the terminal post 120 from each other. An insulating layer 170 is disposed within the housing 110 and covers the outside of the electrode body 131, thereby insulating the outer periphery of the electrode body 131 from the housing 110. This reduces the risk of short circuits, thus improving the safety of the battery cell 100.

[0098] For example, the materials of the first insulating member 160 and / or the second insulating member 190 may be plastic, inorganic insulating materials (such as ceramics, glass, mica, asbestos, quartz, etc.), organic insulating materials (such as rubber, wood, etc.), synthetic polymer materials (such as epoxy resin, polyurethane, silicone, etc.), etc., without specific limitations.

[0099] like Figure 2 and Figure 3 As shown, the insulating layer 170 is further provided with a first vent hole 171 communicating with the exhaust groove 141 on the side near the explosion-proof valve 150, so as to disperse 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 vent hole 171.

[0100] For example, the insulating layer 170 may be a Mylar film (a biaxially oriented polyester film made of polyethylene terephthalate), a polypropylene film, a polyethylene film, a polyvinyl chloride film, a polycarbonate film, etc., without any specific limitation.

[0101] like Figure 2 and Figure 3As 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 detached from the end cap 140 by gas impact when the explosion-proof valve 150 is opened to vent. The protective layer 180 and the explosion-proof valve 150 are arranged opposite to each other in the third direction Y. The protective layer 180 is provided with a second vent hole 181. 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 the explosion-proof valve 150 being opened accidentally.

[0102] It should be noted that, in the battery cell 100 provided in this embodiment, for 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 are respectively disposed in the housing 110, the electrode body 131 includes a positive electrode sheet, a negative electrode sheet and a separator, the separator is disposed between the positive electrode sheet and the negative electrode sheet, the positive electrode sheet, the negative electrode sheet and the separator are formed into the electrode body 131 by a winding process or by a stacking process, the positive tab is connected to the positive electrode sheet, the negative tab is connected to the negative electrode sheet, the positive terminal is connected to the positive tab to serve as the positive terminal when connected to an external circuit, and the negative terminal is connected to the negative tab to serve as the negative terminal when connected to an external circuit, thereby facilitating the charging and discharging of the battery cell 100.

[0103] like Figure 15 As shown, in order to solve the above-mentioned technical problems, the embodiments of this application also provide a battery pack, including a separator 200 and a 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, the separator 200 is provided with an exhaust hole 210 extending through the first direction Z. 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 to the outside of the battery pack.

[0104] like Figures 15 to 17 As shown, in one embodiment, the end cap 140 is welded to the housing 110 to form a weld 148, the weld 148 being located on the inner circumferential side of the housing 110, and the partition 200 is connected to the weld 148.

[0105] It is understandable that when the weld 148 formed between the end cap 140 and the housing 110 is located on the inner circumference of the housing 110, the partition 200 is connected to the weld 148, which can apply a constraint force along the first direction Z to the weld 148, so that the area where the weld 148 is located can withstand greater internal pressure of the housing 110.

[0106] like Figures 18 to 20As shown, in another embodiment, the end cap 140 is welded to the housing 110 to form a weld 148. The weld 148 is located on the outer periphery of the housing 110. A protruding structure 300 is provided on the side of the partition 200 near the end cap 140. The vertical distance from the side of the protruding structure 300 near the pole post 120 to the partition 200 is H3mm. The vertical distance from the side of the weld 148 near the pole post 120 to the partition 200 is H4mm, satisfying: H3>H4. The protruding structure 300 is connected to the weld 148.

[0107] It is understandable that when the weld 148 formed between the end cap 140 and the housing 110 is located on the outer periphery of the housing 110, the protruding structure 300, which is higher than the weld 148, is connected to the weld 148, and a constraint force perpendicular to the first direction Z can be applied to the weld 148, so that the area where the weld 148 is located can withstand greater internal pressure of the housing 110.

[0108] It should be noted that the connection between the partition 200 and the weld 148 and / or the connection between the protruding structure 300 and the weld 148 can be abutment, bonding, welding, screw connection, etc., or can be connected by elastic elements (elastic elements such as polyurethane, silicone, rubber, etc.). That is, the elastic element is set between the partition 200 and the weld 148 / the elastic element is set between the protruding structure 300 and the weld 148. No specific limitation is made here.

[0109] like Figure 21 As shown, the battery cell 100 further has a third direction Y perpendicular to the first direction Z. The protrusion structure 300 has a plurality of positioning holes 310. The number of vent holes 210 and the number of battery cells 100 are both multiple. The plurality of positioning holes 310 and the plurality of vent holes 210 are all spaced apart along the third direction Y. Each positioning hole 310 and one vent hole 210 are arranged opposite to and connected to each other along the first direction Z. Each battery cell 100 passes through one positioning hole 310.

[0110] It should be noted that each positioning hole 310 and an exhaust hole 210 are arranged opposite to each other along the first direction Z and are connected. Each battery cell 100 is inserted through a positioning hole 310, which means that multiple positioning holes 310 and multiple exhaust holes 210 are arranged in a one-to-one correspondence, and multiple battery cells 100 and multiple positioning holes 310 are arranged in a one-to-one correspondence.

[0111] It is understood that, through the multiple positioning holes 310 formed on the protruding structure 300, each battery cell 100 passes through one positioning hole 310, so as to realize the snapping of multiple battery cells 100 onto the protruding structure 300 respectively. This facilitates the positioning of the battery cells 100 when they are assembled onto the separator 200, thereby improving assembly efficiency. It can also limit the movement of the battery cells 100 relative to the separator 200 in a direction perpendicular to the first direction Z. At the same time, the protruding structure 300 is also connected to the weld 148, which can apply a constraint force to the weld 148. That is, the protruding structure 300 has the dual function of facilitating the assembly of the battery cells 100 and enhancing the structural strength of the area where the weld 148 is located.

[0112] 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, which will not be described in detail here.

[0113] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0114] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled 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 by, The battery cell has a first direction (Z) and comprises: a housing (110) which is a one-piece structure and has an opening (111); a pole (120) which is arranged in the housing (110); an electrode assembly (130) which is arranged in the housing (110) and is electrically connected to the pole (120); an end cover (140) which is connected to the housing (110) to cover the opening (111), the end cover (140) and the pole (120) are arranged opposite to each other along the first direction (Z), and the side of the end cover (140) close to the electrode assembly (130) is provided with an exhaust groove (141); an explosion-proof valve (150) which is arranged on the end cover (140), and the explosion-proof valve (150) and the exhaust groove (141) are arranged opposite to each other along the first direction (Z).

2. The battery cell of claim 1, wherein, The side of the end cover (140) close to the electrode assembly (130) is provided with a plurality of support protrusions (142), the plurality of support protrusions (142) are arranged in the exhaust groove (141) at intervals, the support protrusions (142) and the explosion-proof valve (150) are arranged at intervals, and the support protrusions (142) abut against the electrode assembly (130).

3. The battery cell of claim 2, wherein, The battery cell has a second direction (X) which is perpendicular to the first direction (Z), and the orthogonal projections of two adjacent support protrusions (142) along the second direction (X) on a plane perpendicular to the second direction (X) at least partially coincide.

4. The battery cell of claim 3, wherein, The plurality of support protrusions (142) are connected to the side wall of the exhaust groove (141), each of the support protrusions (142) is arranged in an extending manner close to the explosion-proof valve (150), and the side of each of the support protrusions (142) close to the electrode assembly (130) is an arc surface (1421) which abuts against the electrode assembly (130).

5. The battery cell of claim 3, wherein, Some of the plurality of support protrusions (142) are connected to the bottom wall of the exhaust groove (141), and the side of the support protrusions (142) close to the electrode assembly (130) is a circular surface (1422) which abuts against the electrode assembly (130); the other of the plurality of support protrusions (142) are connected to the side wall of the exhaust groove (141), and the side of the support protrusions (142) close to the electrode assembly (130) is a semicircular surface (1423) which abuts against the electrode assembly (130).

6. The battery cell of claim 3, wherein, The battery monomer has a third direction (Y) perpendicular to the first direction (Z) and the second direction (X) two by two, a plurality of the support protrusions (142) are arranged along the second direction (X), each of the support protrusions (142) is arranged along the third direction (Y), and the side of each of the support protrusions (142) close to the electrode assembly (130) is an oval surface (1424) abutting against the electrode assembly (130).

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

8. The battery cell of claim 7, wherein, 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 of the support protrusions (142) close to the electrode assembly (130) to the bottom wall of the exhaust groove (141) is H2 mm, and H1 < H2 is satisfied.

9. The battery cell of claim 8, wherein, The first reinforcing protrusion (143) is provided with a notch (144) penetrating the first reinforcing protrusion (143), and the notch (144) is in communication with the exhaust groove (141).

10. The battery cell of claim 1, wherein, The side of the end cover (140) away from the electrode assembly (130) is provided with a plurality of grooves (145), and adjacent two of the grooves (145) are arranged at intervals, the groove (145) and the exhaust groove (141) are arranged opposite along the first direction (Z).

11. The battery cell of claim 10, wherein, The side of the end cover (140) away from the electrode assembly (130) is provided with a second reinforcing protrusion (146), the groove (145) and the second reinforcing protrusion (146) are arranged at intervals, the second reinforcing protrusion (146) is located at the edge of the end cover (140) and surrounds the explosion-proof valve (150), and the second reinforcing protrusion (146) is connected with the shell (110).

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

13. The battery cell of claim 12, wherein, The number of the score grooves (147) is a plurality, and a plurality of the score grooves (147) are arranged at intervals along the second direction (X), and the score groove (147) and the explosion-proof valve (150) are arranged at intervals along the second direction (X).

14. A battery pack, characterized by The battery cell includes a separator (200) and the end cover (140) disposed on the separator (200), wherein the separator (200) is provided with an exhaust hole (210) penetrating in the first direction (Z), and the exhaust hole (210) and the explosion-proof valve (150) are oppositely disposed in the first direction (Z).

15. The battery pack of claim 14, wherein, The end cover (140) is welded with the shell (110) to form a weld (148), and the weld (148) is located on the inner circumferential side of the shell (110), and the separator (200) is connected with the weld (148).

16. The battery pack of claim 14, wherein, The end cover (140) is welded with the shell (110) to form a weld (148), and the weld (148) is located on the outer circumferential side of the shell (110), and the side of the separator (200) close to the end cover (140) is provided with a protruding structure (300), the vertical distance from the side of the protruding structure (300) close to the pole column (120) to the separator (200) is H3 mm, the vertical distance from the side of the weld (148) close to the pole column (120) to the separator (200) is H4 mm, and H3>H4 is satisfied, and the protruding structure (300) is connected with the weld (148).

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