Battery monomer, battery and electric equipment

Abstract

The embodiment of the utility model provides a battery monomer, a battery and electric equipment. The battery cell includes a housing and an electrode assembly. The shell comprises an end wall and a side wall, the end wall is arranged at one end, in the first direction, of the side wall, and the side wall surrounds the end wall. The electrode assembly is contained in the shell, and a first flow guide channel is formed between a tab at one end, facing the end wall, of the electrode assembly and the side wall. The end wall comprises a wall body and an abutting part, the wall body is provided with a pressure relief mechanism, and the abutting part is arranged on the outer edge of the wall body in a surrounding mode. In the first direction, the abutting portion protrudes from the wall body in the direction close to the electrode assembly and directly or indirectly abuts against the tab. The abutting part and the wall body jointly define a flow guide space, the abutting part is provided with a second flow guide channel, and the second flow guide channel communicates with the flow guide space and the first flow guide channel. When the single battery is in thermal runaway, emissions generated by the electrode assembly can quickly flow to the flow guide space through the second flow guide channel on the abutting part, so that the reliability of the single battery is effectively improved.

Description

Technical Field

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

[0002] In recent years, new energy vehicles have developed by leaps and bounds. In the field of electric vehicles, power batteries, as the power source of electric vehicles, play an irreplaceable and important role. With the vigorous promotion of new energy vehicles, the demand for power battery products is also growing. As the demand for batteries increases, higher requirements are placed on the reliability of battery cells. Therefore, how to improve the reliability of battery cells is an urgent problem to be solved in battery technology. Utility Model Content

[0003] The embodiments of the present application provide a battery cell, a battery and an electrical device, which can effectively improve the reliability of the battery cell.

[0004] In a first aspect, an embodiment of the present application provides a battery cell, comprising an outer shell and an electrode assembly; the outer shell comprises an end wall and a side wall, the end wall is arranged at one end of the side wall along a first direction, and the side wall is arranged around the end wall; the electrode assembly is accommodated in the outer shell, and the end of the electrode assembly facing the end wall has a pole ear, and a first guide channel is formed between the pole ear and the side wall; wherein the end wall comprises a wall body and a supporting portion, the wall body is provided with a pressure relief mechanism, and the supporting portion is arranged around the outer edge of the wall body; along the first direction, the supporting portion protrudes from the wall body in a direction close to the electrode assembly, and directly or indirectly abuts against the pole ear; the supporting portion and the wall body jointly define a guide space, and the supporting portion is provided with a second guide channel, and the second guide channel connects the guide space and the first guide channel.

[0005] In the above technical solution, the abutting portion of the end wall directly or indirectly abuts against the pole ear, and the abutting portion can play a limiting role on the electrode assembly, reducing the risk of the electrode assembly moving in the first direction in the housing. Since the abutting portion is provided with a second guide channel, the second guide channel connects the guide space and the first guide channel. When the battery cell is in thermal runaway, the emissions generated by the electrode assembly flow into the first guide channel. The emissions can flow quickly into the guide space through the second guide channel on the abutting portion, so that the air pressure in the guide space rises rapidly to quickly reach the bursting pressure of the pressure relief mechanism, shortening the time from the thermal runaway of the battery cell to the pressure relief of the battery cell through the pressure relief mechanism, so that the pressure relief mechanism can be actuated in time, reducing the risk of explosion and fire of the battery cell, and effectively improving the reliability of the battery cell.

[0006] In some embodiments, the abutment portion is provided with a plurality of second flow guiding channels, which are arranged at intervals along the circumference of the abutment portion, so that the emissions in the first flow guiding channel can enter the flow guiding space from the plurality of second flow guiding channels at different positions, thereby increasing the rate at which the emissions in the first flow guiding channel enter the flow guiding space, and further shortening the time from thermal runaway of the battery cell to the start of pressure relief of the battery cell through the pressure relief mechanism.

[0007] In some embodiments, along the first direction, the abutting portion has an abutting surface, the abutting surface is the surface of the abutting portion closest to the electrode assembly, and the second guide channel is a notch groove that penetrates the abutting portion in the radial direction of the abutting portion and extends to the abutting surface along the first direction. In this way, on the one hand, the difficulty of forming the second guide channel can be reduced, and on the other hand, it is conducive to increasing the size of the second guide channel along the first direction, and increasing the rate at which the discharge in the first guide channel enters the guide space through the second guide channel.

[0008] In some embodiments, the abutting portion includes a plurality of protrusions, and the plurality of protrusions abut against the pole ear directly or indirectly, and a second guide channel is formed between two adjacent protrusions along the circumference of the abutting portion. By forming a second guide channel between two adjacent protrusions, the discharge in the first guide channel can enter the guide space from the plurality of second guide channels at different positions, thereby increasing the rate at which the discharge in the first guide channel enters the guide space. In addition, the second guide channel of this structure is a notch groove formed on the abutting portion, which can reduce the difficulty of forming the second guide channel and is conducive to increasing the size of the second guide channel along the first direction.

[0009] In some embodiments, the protrusion has a butting surface, which is used to directly or indirectly butt against the pole ear to achieve electrical connection between the end wall and the electrode assembly; along the first direction, the height of the protrusion is H; along the radial direction of the butt portion, the width of the butt surface is W; 0.1W≤H≤0.5W. The electrical connection between the end wall and the electrode assembly can be achieved by directly or indirectly butting against the pole ear by the butt surface. In order to achieve stable flow between the end wall and the electrode assembly, the butt surface generally has a certain width. Therefore, the height of the protrusion is controlled within the range of 0.1W to 0.5W, which can not only make the size of the second guide channel along the first direction meet the flow requirements, so that the discharge in the first guide channel can quickly enter the guide space through the second guide channel, but also reduce the influence of the excessive height of the protrusion on the volume energy density of the battery cell.

[0010] In some embodiments, along the first direction, the height of the protrusion is H, 5mm≥H≥0.5mm. H≥0.5mm, so that the size of the second flow guide channel along the first direction is greater than or equal to 0.5mm, so that the size of the second flow guide channel along the first direction meets the flow requirement, so that the discharge in the first flow guide channel can quickly enter the flow guide space through the second flow guide channel; H≤5mm, so that the height of the protrusion is not too large, reducing the space occupied by the protrusion inside the shell along the first direction, which is conducive to improving the volume energy density of the battery cell. In this way, the flow requirement of the second flow guide channel and the volume energy density requirement of the battery cell are taken into account.

[0011] In some embodiments, along the circumference of the abutment portion, the protrusion has a first end and a second end opposite to each other; the projection of the outer edge of the end wall along the first direction forms a first circle; when viewed along the first direction, the line connecting the first end and the center of the first circle is the first line, the line connecting the second end and the center of the first circle is the second line, and the angle between the first line and the second line is α, 15°≤α≤60°. α is controlled between 15° and 60°, so that more protrusions can be arranged along the circumference of the abutment portion to form more second guide channels, so that the discharge in the first guide channel can enter the guide space from more positions.

[0012] In some embodiments, multiple protrusions are evenly arranged along the circumference of the abutting portion, so that multiple second guide channels on the abutting portion can be evenly arranged along the circumference of the abutting portion, so that the emissions in the second guide channels can enter the guide space more evenly from the multiple guide channels, further increasing the rate at which the emissions in the first guide channels enter the guide space.

[0013] In some embodiments, a flow guide gap is formed between the side wall and the protrusion along the radial direction of the abutment portion; the flow guide gap connects two adjacent second flow guide channels. The flow guide gap between the side wall and the protrusion can connect two adjacent second flow guide channels. When the emissions in the first flow guide channel flow to a certain second flow guide channel, the emissions can flow to another adjacent second flow guide channel through the flow guide gap, so that the emissions in the first flow guide channel can enter the flow guide space more quickly.

[0014] In some embodiments, the abutting portion further comprises a main body portion, which is disposed around the outer edge of the wall body and protrudes from the wall body in a direction close to the electrode assembly, and along the first direction, the main body portion has a first surface facing the electrode assembly, and the protrusion portion is disposed on the first surface. The main body portion serves to connect the wall body and the protrusion portion, and the main body portion is disposed around the wall body and protrudes from the wall body in a direction close to the electrode assembly, which can effectively improve the deformation resistance of the end wall.

[0015] In some embodiments, along the first direction, the wall body has a second surface, the second surface is the surface of the wall body closest to the electrode assembly, and the first surface is closer to the electrode assembly than the second surface. In this way, the distance between the second surface and the electrode assembly can be increased, the influence of the electrode assembly on the pressure relief mechanism on the wall body is reduced, and the size of the diversion space along the first direction can be effectively increased.

[0016] In some embodiments, the abutment portion is provided with a first groove; along the first direction, the body portion has a third surface arranged opposite to the first surface, the first surface is closer to the electrode assembly than the third surface, and the first groove is recessed from the third surface toward the electrode assembly to form a protrusion protruding from the first surface on the side of the body portion facing the electrode assembly. By providing the first groove on the abutment portion to form a corresponding protrusion, the difficulty of forming the protrusion can be effectively reduced, and the weight of the end wall can be effectively reduced.

[0017] In some embodiments, the first groove is a multi-stage groove, and along the first direction, the first-stage groove close to the electrode assembly in the adjacent two-stage groove is arranged at the groove bottom surface of the first-stage groove far away from the electrode assembly. By setting the first groove as a multi-stage groove, the forming force on the end wall when forming each stage of the groove is lower, thereby reducing the risk of the end wall being damaged due to excessive forming force when forming the first groove.

[0018] In some embodiments, the protrusion includes a first part and a second part, and the multi-level groove includes a first-level groove and a second-level groove; the first-level groove is recessed from the third surface toward the direction close to the electrode assembly to form a first part protruding from the first surface on the side of the body part facing the electrode assembly, and along the first direction, the first part has a fourth surface facing the electrode assembly; the second-level groove is recessed from the groove bottom surface of the first-level groove toward the direction close to the electrode assembly to form a second part protruding from the fourth surface on the side of the first part facing the electrode assembly. By providing the first-level groove on the body part, the first part of the protrusion can be formed accordingly, and by providing the second-level groove on the first part, the second part of the protrusion can be formed accordingly, which can reduce the difficulty of forming the protrusion.

[0019] In some embodiments, along the radial direction of the abutment portion, the first part has a first side surface facing the inner circumference of the side wall, the second part has a second side surface facing the inner circumference of the side wall, the first side surface is closer to the inner circumference of the side wall than the second side surface, a guide gap is formed between the second side surface and the inner circumference of the side wall, and the guide gap connects two adjacent second guide channels. The guide gap between the second side surface and the inner circumference of the side wall can connect two adjacent second guide channels, and when the emissions in the first guide channel flow to a certain second guide channel, the emissions can flow to another adjacent second guide channel through the guide gap, so that the emissions in the first guide channel can enter the guide space more quickly.

[0020] In some embodiments, a second groove is provided at a position corresponding to the main body on one side of the end wall away from the electrode assembly, and the third surface is the bottom surface of the second groove. By providing the second groove on the end wall to form the main body, the difficulty of forming the main body can be effectively reduced.

[0021] In some embodiments, the end wall and the side wall are separately provided, and at least a part of the main body is accommodated in the side wall and forms a positioning match with the side wall. The positioning match between the main body and the side wall can effectively improve the assembly difficulty of the end wall and the side wall.

[0022] In some embodiments, the end wall further includes an edge portion, which is disposed around the outer edge of the main body portion, and the edge portion abuts against one end of the side wall along the direction of the end wall pointing toward the electrode assembly. The abutment between the edge portion and the side wall can achieve the position limitation of the end wall, and restrict the end wall from moving in the direction close to the electrode assembly.

[0023] In some embodiments, the wall body and the abutting portion are integrally formed, so that the connection strength between the abutting portion and the wall body can be effectively improved.

[0024] In some embodiments, along the first direction, the wall body has a fifth surface, which is the surface of the end wall farthest from the electrode assembly, and the pressure relief mechanism is closer to the electrode assembly than the fifth surface. This increases the distance between the pressure relief mechanism and the external component when the fifth surface contacts the external component, reduces the impact of the external component on the pressure relief mechanism, and reduces the risk of the pressure relief mechanism being actuated prematurely by the impact force of the external component.

[0025] In some embodiments, the wall body is provided with a third groove, the third groove is recessed from the fifth surface toward the direction close to the electrode assembly, and the groove bottom wall of the third groove is provided with a pressure relief groove, so as to form a pressure relief mechanism at a position where the groove bottom wall of the third groove corresponds to the pressure relief groove. By providing the third groove recessed from the fifth surface toward the direction close to the electrode assembly in the wall body, and providing the pressure relief groove on the groove bottom wall of the third groove to form the pressure relief mechanism accordingly, the pressure relief mechanism is achieved to be closer to the electrode assembly than the fifth surface, and the implementation method is simple.

[0026] In some embodiments, the wall body is provided with a pressure relief groove to form a pressure relief mechanism at a position of the wall body corresponding to the pressure relief groove. By providing the pressure relief groove on the wall body to form an integrated pressure relief mechanism, the pressure relief mechanism is formed in a simple manner and has higher reliability.

[0027] In some embodiments, the battery cell further comprises a current collecting member, which is disposed between the end wall and the electrode assembly along the first direction, the current collecting member electrically connects the electrode assembly and the end wall, the abutting portion directly abuts against the current collecting member, and the current collecting member directly abuts against the electrode ear. The current collecting member can realize electrical connection between the electrode assembly and the end wall, thereby reducing the difficulty of electrical connection between the electrode assembly and the end wall.

[0028] In some embodiments, the electrode assembly is provided with a first central hole, the current collecting member is provided with a second central hole, and the second central hole is connected to the first central hole and the flow guiding space. When the battery cell is in thermal runaway, the emissions generated by the electrode assembly can enter the flow guiding space through the first central hole and the second central hole in sequence, further shortening the time from the thermal runaway of the battery cell to the pressure relief of the battery cell through the pressure relief mechanism, so that the pressure relief mechanism can be actuated more timely.

[0029] In some embodiments, the housing includes a shell and an end cover; the shell is formed with an opening at at least one end along the first direction; the end cover closes the opening; wherein at least one end cover is an end wall, and the shell includes a side wall. At least one end cover is an end wall, so that at least one end cover is provided with a pressure relief mechanism, which reduces the molding difficulty or installation difficulty of the pressure relief mechanism, and the second guide channel is provided on the end cover, which reduces the molding difficulty of the second guide channel.

[0030] In some embodiments, the battery cells are cylindrical battery cells.

[0031] In a second aspect, an embodiment of the present application provides a battery, comprising a battery cell provided by any embodiment of the first aspect.

[0032] In a third aspect, an embodiment of the present application further provides an electrical device, comprising a battery cell improved according to any one of the embodiments of the first aspect, wherein the battery cell is used to provide electrical energy to the electrical device. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0034] Figure 1 A schematic diagram of the structure of a vehicle provided in some embodiments of the present application;

[0035] Figure 2 An exploded view of a battery provided for some embodiments of the present application;

[0036] Figure 3 An exploded view of a battery cell provided for some embodiments of the present application;

[0037] Figure 4 for Figure 3 A cross-sectional view of a battery cell is shown;

[0038] Figure 5 for Figure 4 A partial enlarged view of a battery cell shown;

[0039] Figure 6 for Figure 5 A schematic diagram of the structure of the end wall shown;

[0040] Figure 7 for Figure 6 AA section view of the end wall shown;

[0041] Figure 8 for Figure 7 A view of the end wall as shown in direction B;

[0042] Fig. 9 A partial enlarged view of a battery cell provided in some other embodiments of the present application;

[0043] Fig.10 for Fig. 9 A partial enlarged view of point C in the middle;

[0044] Fig.11 for Fig. 9 A schematic diagram of the structure of the end wall shown;

[0045] Fig.12 for Fig.11 DD section view of the end wall shown.

[0046] Icons: 1-shell; 11-shell; 12-end cover; 13-end wall; 131-wall body; 1311-second surface; 1312-fifth surface; 1313-sixth surface; 1314-third groove; 13141-bottom wall of the third groove; 1315-reinforcement rib; 1316-pressure relief groove; 132-abutment portion; 1321-second flow guide channel; 1322-abutment surface; 1323-protrusion; 13231-first end; 13232-second end; 13233-first part; 13233a-fourth surface; 13233b-first side surface; 13234-second part; 13234a-second side surface; 1324-body; 13241-first surface; 13242-third surface; 1325-first groove; 13251-first-stage groove; 13252-second-stage groove; 133-conducting space; 134-second groove; 135-edge; 14-side wall; 141-inner circumferential surface; 2-electrode assembly; 21-ear; 22-main body; 23-first center hole; 3-electrode terminal; 4-current collecting member; 41-second center hole; 5-pressure relief mechanism; 6-first conduit channel; 7-conducting gap; 10-battery cell; 20-housing; 201-first housing; 202-second housing; 100-battery; 200-controller; 300-motor; 1000-vehicle; Q-first circle; U-first connecting line; V-second connecting line; X-first direction; Y-circumferential direction of the abutment; Z-radial direction of the abutment. DETAILED DESCRIPTION

[0047] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0048] Unless otherwise defined, all technical and scientific terms used in this application have the same meanings as those commonly understood by technicians in the technical field of this application; the terms used in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned drawings and any variations thereof are intended to cover non-exclusive inclusions. The terms "first", "second", etc. in the specification and claims of this application or the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order or a primary and secondary relationship.

[0049] Reference to "embodiment" in this application means that a particular feature, structure, or characteristic described in conjunction with the embodiment may be included in at least one embodiment of the present application. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments.

[0050] In the description of the present application, it should be noted that, unless otherwise clearly specified and limited, the terms "installation" and "connection" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to the specific circumstances.

[0051] The term "and / or" in this application is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this application generally indicates that the associated objects before and after are in an "or" relationship.

[0052] In the embodiments of the present application, the same reference numerals represent the same components, and for the sake of brevity, detailed descriptions of the same components are omitted in different embodiments. It should be understood that the thickness, length, width and other dimensions of various components in the embodiments of the present application shown in the drawings, as well as the overall thickness, length, width and other dimensions of the integrated device are only exemplary descriptions and should not constitute any limitation to the present application.

[0053] The term "plurality" used in the present application refers to two or more (including two).

[0054] In the embodiment of the present application, the battery cell may be a secondary battery. A secondary battery refers to a battery cell that can be continuously used by activating active materials by charging after the battery cell is discharged.

[0055] Battery cells include, but are not limited to, lithium-ion batteries, sodium-ion batteries, sodium-lithium-ion batteries, lithium metal batteries, sodium metal batteries, lithium-sulfur batteries, magnesium-ion batteries, nickel-hydrogen batteries, nickel-cadmium batteries, lead-acid batteries, and the like.

[0056] A battery cell generally includes an electrode assembly. The electrode assembly includes a positive electrode, a negative electrode, and a separator. During the charge and discharge process of the battery cell, active ions (such as lithium ions) are embedded and removed between the positive electrode and the negative electrode. The separator is set between the positive electrode and the negative electrode to reduce the risk of short circuit between the positive and negative electrodes, while allowing active ions to pass through.

[0057] In some embodiments, the positive electrode may be a positive electrode sheet, and the positive electrode sheet may include a positive electrode current collector and a positive electrode active material disposed on at least one surface of the positive electrode current collector.

[0058] As an example, the positive electrode current collector has two surfaces facing each other in its thickness direction, and the positive electrode active material is disposed on either or both of the two facing surfaces of the positive electrode current collector.

[0059] As an example, the positive electrode current collector may be a metal foil or a composite current collector. For example, as the metal foil, aluminum with a silver-plated surface, stainless steel with a silver-plated surface, stainless steel, copper, aluminum, nickel, carbon electrode, carbon, nickel or titanium, etc. may be used. The composite current collector may include a polymer material base and a metal layer. The composite current collector may be formed by forming a metal material (aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0060] As an example, the positive electrode active material may include at least one of the following materials: lithium-containing phosphates, lithium transition metal oxides and their respective modified compounds. However, the present application is not limited to these materials, and other traditional materials that can be used as positive electrode active materials for batteries can also be used. These positive electrode active materials can be used alone or in combination of two or more. Among them, examples of lithium-containing phosphates may include, but are not limited to, at least one of lithium iron phosphate (such as LiFePO4 (also referred to as LFP)), a composite material of lithium iron phosphate and carbon, lithium manganese phosphate (such as LiMnPO4), a composite material of lithium manganese phosphate and carbon, lithium iron manganese phosphate, and a composite material of lithium iron manganese phosphate and carbon. Examples of lithium transition metal oxides may include, but are not limited to, lithium cobalt oxide (such as LiCoO2), lithium nickel oxide (such as LiNiO2), lithium manganese oxide (such as LiMnO2, LiMn2O4), lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, lithium nickel cobalt manganese oxide (such as LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 O2 (also referred to as NCM 333 )、LiNi 0.5 Co 0.2 Mn 0.3 O2 (also referred to as NCM 523 )、LiNi 0.5 Co 0.25 Mn 0.25 O2 (also referred to as NCM 211 )、LiNi 0.6 Co 0.2 Mn 0.2 O2 (also referred to as NCM 622 )、LiNi 0.8 Co 0.1 Mn 0.1 O2 (also referred to as NCM811 ), lithium nickel cobalt aluminum oxide (such as LiNi 0.85 Co 0.15 Al 0.05 O2) and its modified compounds, etc.

[0061] In some embodiments, the positive electrode may be a foamed metal. The foamed metal may be a nickel foam, a copper foam, an aluminum foam, an alloy foam, etc. When the foamed metal is used as the positive electrode, the positive electrode active material may not be provided on the surface of the foamed metal, but of course, the positive electrode active material may also be provided. As an example, a lithium source material, potassium metal or sodium metal may also be filled or / and deposited in the foamed metal, and the lithium source material is lithium metal and / or a lithium-rich material.

[0062] In some embodiments, the negative electrode may be a negative electrode sheet, and the negative electrode sheet may include a negative electrode current collector.

[0063] As an example, the negative electrode current collector may be a metal foil, a foamed metal or a composite current collector. For example, as the metal foil, aluminum or stainless steel, stainless steel, copper, aluminum, nickel, carbon electrode, carbon, nickel or titanium, etc., treated with silver surface, may be used. The foamed metal may be a nickel foam, a copper foam, an aluminum foam, an alloy foam, etc. The composite current collector may include a polymer material base and a metal layer. The composite current collector may be formed by forming a metal material (copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0064] As an example, the negative electrode sheet may include a negative electrode current collector and a negative electrode active material disposed on at least one surface of the negative electrode current collector.

[0065] As an example, the negative electrode current collector has two surfaces facing each other in its thickness direction, and the negative electrode active material is disposed on either or both of the two facing surfaces of the negative electrode current collector.

[0066] As an example, the negative electrode active material may adopt the negative electrode active material for battery cells known in the art. As an example, the negative electrode active material may include at least one of the following materials: artificial graphite, natural graphite, soft carbon, hard carbon, silicon-based materials, tin-based materials, lithium titanate, etc. The silicon-based material may be selected from at least one of elemental silicon, silicon oxide compounds, silicon-carbon composites, silicon-nitrogen composites, and silicon alloys. The tin-based material may be selected from at least one of elemental tin, tin oxide compounds, and tin alloys. However, the present application is not limited to these materials, and other traditional materials that can be used as negative electrode active materials for batteries may also be used. These negative electrode active materials may be used alone or in combination of two or more.

[0067] In some embodiments, the material of the positive electrode current collector may be aluminum, and the material of the negative electrode current collector may be copper.

[0068] In some embodiments, the separator is a separator membrane, which can be any known porous separator membrane with good chemical stability and mechanical stability.

[0069] As an example, the material of the separator may include at least one of glass fiber, non-woven fabric, polyethylene, polypropylene and polyvinylidene fluoride. The separator may be a single-layer film or a multi-layer composite film. When the separator is a multi-layer composite film, the materials of each layer may be the same or different. The separator may be a separate component located between the positive and negative electrodes, or may be attached to the surface of the positive and negative electrodes.

[0070] In some embodiments, the separator is a solid electrolyte, which is disposed between the positive electrode and the negative electrode and serves to transmit ions and isolate the positive and negative electrodes.

[0071] In some embodiments, the battery cell further includes an electrolyte, which plays a role in conducting ions between the positive and negative electrodes. The electrolyte can be liquid, gel or solid. Among them, the liquid electrolyte includes an electrolyte salt and a solvent.

[0072] In some embodiments, the electrolyte salt may include at least one of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium hexafluoroarsenate, lithium bisfluorosulfonyl imide, lithium bistrifluoromethanesulfonyl imide, lithium trifluoromethanesulfonate, lithium difluorophosphate, lithium difluorooxalatoborate, lithium dioxalatoborate, lithium difluorodioxalatophosphate, and lithium tetrafluorooxalatophosphate.

[0073] In some embodiments, the solvent may include at least one of ethylene carbonate, propylene carbonate, ethyl methyl carbonate, diethyl carbonate, dimethyl carbonate, dipropyl carbonate, methyl propyl carbonate, ethyl propyl carbonate, butylene carbonate, fluoroethylene carbonate, methyl formate, methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, propyl propionate, methyl butyrate, ethyl butyrate, 1,4-butyrolactone, cyclopentane, dimethyl sulfone, methyl ethyl sulfone and diethyl sulfone. The solvent may also be an ether solvent. The ether solvent may include one or more of ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, 1,3-dioxolane, tetrahydrofuran, methyltetrahydrofuran, diphenyl ether and crown ether.

[0074] Among them, the gel electrolyte includes a skeleton network with a polymer as the electrolyte, combined with an ionic liquid-lithium salt.

[0075] Among them, solid electrolytes include polymer solid electrolytes, inorganic solid electrolytes, and composite solid electrolytes.

[0076] As an example, the polymer solid electrolyte may be polyether (polyethylene oxide), polysiloxane, polycarbonate, polyacrylonitrile, polyvinylidene fluoride, polymethyl methacrylate, a single ion polymer, polyionic liquid-lithium salt, cellulose, and the like.

[0077] As an example, the inorganic solid electrolyte may include an oxide solid electrolyte (crystalline perovskite, sodium superconducting ion conductor, garnet, amorphous LiPON film), a sulfide solid electrolyte (crystalline lithium superion conductor (lithium germanium phosphosulfide, silver germanium sulfide), amorphous sulfide) and one or more of a halide solid electrolyte, a nitride solid electrolyte and a hydride solid electrolyte.

[0078] As an example, the composite solid electrolyte is formed by adding an inorganic solid electrolyte filler to a polymer solid electrolyte.

[0079] In some embodiments, the electrode assembly is a wound structure, wherein the positive electrode sheet and the negative electrode sheet are wound into a wound structure.

[0080] In some embodiments, the electrode assembly is a laminate structure.

[0081] As an example, a plurality of positive electrode sheets and a plurality of negative electrode sheets may be provided respectively, and the plurality of positive electrode sheets and the plurality of negative electrode sheets may be alternately stacked.

[0082] As an example, a plurality of positive electrode sheets may be provided, and the negative electrode sheet is folded to form a plurality of stacked folded segments, with a positive electrode sheet sandwiched between adjacent folded segments.

[0083] As an example, both the positive electrode sheet and the negative electrode sheet are folded to form a plurality of stacked folded sections.

[0084] As an example, a plurality of separators may be provided, each of which is provided between any adjacent positive electrode sheets or negative electrode sheets.

[0085] As an example, the separator may be disposed continuously, and may be disposed between any adjacent positive electrode sheets or negative electrode sheets by folding or winding.

[0086] In some embodiments, the shape of the electrode assembly can be cylindrical, flat, or polygonal.

[0087] In some embodiments, the electrode assembly is provided with tabs, which can lead current out of the electrode assembly. The tabs include a positive tab and a negative tab.

[0088] In some embodiments, the battery cell may include a housing. The housing is used to encapsulate components such as the electrode assembly and the electrolyte. The housing may be a steel housing, an aluminum housing, a plastic housing (such as polypropylene), a composite metal housing (such as a copper-aluminum composite housing), or an aluminum-plastic film.

[0089] As an example, the battery cell may be a cylindrical battery cell, a prismatic battery cell, a soft-pack battery cell or a battery cell of other shapes. The prismatic battery cell includes a square-shell battery cell, a blade-shaped battery cell, a polygonal battery cell, such as a hexagonal battery cell.

[0090] The battery mentioned in the embodiments of the present application refers to a single physical module including one or more battery cells to provide higher voltage and capacity.

[0091] In some embodiments, the battery may be a battery module. When there are multiple battery cells, the multiple battery cells are arranged and fixed to form a battery module.

[0092] In some embodiments, the battery may be a battery pack, which includes a case and battery cells, wherein the battery cells or battery modules are accommodated in the case.

[0093] In some embodiments, the box body can be used as a part of the chassis structure of the vehicle. For example, part of the box body can become at least a part of the floor of the vehicle, or part of the box body can become at least a part of the cross beam and longitudinal beam of the vehicle.

[0094] In some embodiments, the battery may be an energy storage device, which includes an energy storage container, an energy storage cabinet, and the like.

[0095] In some embodiments, to improve the reliability of the battery cell, a pressure relief mechanism may be generally provided on the end wall of the battery cell housing, and when the battery cell thermally runs away, the pressure inside the battery cell may be released through the pressure relief mechanism.

[0096] The pressure relief mechanism refers to an element or component that is activated to release the internal pressure of the battery cell when the internal pressure reaches a predetermined threshold. The threshold design varies according to different design requirements. The threshold may depend on one or more materials of the positive electrode plate, negative electrode plate, electrolyte and separator in the battery cell.

[0097] The "actuation" mentioned in this application means that the pressure relief mechanism is in motion or activated to a certain state, so that the internal pressure of the battery cell can be released. The action produced by the pressure relief mechanism may include but is not limited to: at least a part of the pressure relief mechanism is ruptured, broken, torn or opened, etc. When the pressure relief mechanism is actuated, the high-temperature and high-pressure substances inside the battery cell will be discharged from the actuated part as emissions. In this way, the battery cell can be depressurized under controllable pressure, thereby avoiding potential more serious accidents.

[0098] The emissions from the battery cells mentioned in the embodiments of the present application include, but are not limited to: electrolyte, dissolved or split positive and negative electrode plates, fragments of the isolation membrane, high-temperature and high-pressure gases produced by the reaction, flames, etc.

[0099] In a general battery cell, abutment portion protruding toward the electrode assembly can be formed on the end wall provided with a pressure relief mechanism, and the abutment portion directly or indirectly abuts against the electrode lug of the electrode assembly to reduce the movement of the electrode assembly in the housing. However, since the abutment portion directly or indirectly abuts against the electrode lug of the electrode assembly, when the battery cell thermally runs away, the discharge between the electrode assembly and the side wall of the housing is difficult to reach the area of ​​the end wall provided with the pressure relief mechanism, and the pressure relief mechanism cannot be actuated in time, resulting in the risk of explosion and fire of the battery cell, affecting the reliability of the battery cell.

[0100] In order to solve the problem of poor reliability of battery cells, an embodiment of the present application provides a battery cell, wherein the end wall of the shell includes a wall body and a supporting portion, wherein the wall body is provided with a pressure relief mechanism, and the supporting portion is arranged around the outer edge of the wall body. The supporting portion protrudes from the wall body in a direction close to the electrode assembly, and directly or indirectly abuts against the electrode assembly, and a first guide channel is formed between the electrode assembly and the side wall of the shell. The supporting portion and the wall body together define a guide space, and the supporting portion is provided with a second guide channel, and the second guide channel connects the guide space and the first guide channel.

[0101] In such a battery cell, since the abutment portion is provided with a second guide channel, the second guide channel connects the guide space and the first guide channel. When the battery cell thermally runs away, after the emissions generated by the electrode assembly flow into the first guide channel, the emissions can quickly flow into the guide space through the second guide channel on the abutment portion, so that the air pressure in the guide space rises rapidly to quickly reach the bursting pressure of the pressure relief mechanism, shortening the time from thermal runaway of the battery cell to the battery cell starting to release pressure through the pressure relief mechanism, so that the pressure relief mechanism can be actuated in time, reducing the risk of explosion and fire of the battery cell, and effectively improving the reliability of the battery cell.

[0102] The battery cells described in the embodiments of the present application are suitable for batteries and electrical equipment using the battery cells.

[0103] Electrical equipment can be vehicles, mobile phones, portable devices, laptops, ships, spacecraft, electric toys and electric tools, etc. Vehicles can be fuel vehicles, gas vehicles or new energy vehicles, and new energy vehicles can be pure electric vehicles, hybrid vehicles or extended-range vehicles, etc.; spacecraft include aircraft, rockets, space shuttles and spacecraft, etc.; electric toys include fixed or mobile electric toys, such as game consoles, electric car toys, electric ship toys and electric airplane toys, etc.; electric tools include metal cutting electric tools, grinding electric tools, assembly electric tools and railway electric tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators and electric planers, etc.

[0104] For the convenience of description, the following embodiments are described by taking the electric device as a vehicle as an example.

[0105] Please refer to Figure 1 , Figure 1 The schematic diagram of the structure of the vehicle 1000 provided in some embodiments of the present application. The vehicle 1000 is provided with a battery 100 inside, and the battery 100 can be provided at the bottom, head or tail of the vehicle 1000. The battery 100 can be used to power the vehicle 1000, for example, the battery 100 can be used as an operating power source of the vehicle 1000.

[0106] The vehicle 1000 may further include a controller 200 and a motor 300 , wherein the controller 200 is used to control the battery 100 to supply power to the motor 300 , for example, to meet the power requirements of starting, navigating, and driving the vehicle 1000 .

[0107] In some embodiments of the present application, the battery 100 can not only serve as an operating power source for the vehicle 1000, but also serve as a driving power source for the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0108] Please refer to Figure 2 , Figure 2 The exploded view of the battery 100 provided in some embodiments of the present application. The battery 100 includes a battery cell 10 and a box body 20, and the battery cell 10 is accommodated in the box body 20.

[0109] Among them, the box body 20 is a component for accommodating the battery cell 10, and the box body 20 provides a storage space for the battery cell 10. The box body 20 can adopt a variety of structures. In some embodiments, the box body 20 may include a first box body 201 and a second box body 202, and the first box body 201 and the second box body 202 cover each other to define a storage space for accommodating the battery cell 10. The first box body 201 and the second box body 202 can be in a variety of shapes, such as a rectangular parallelepiped, a cylindrical shape, etc. The first box body 201 can be a hollow structure with one side open, and the second box body 202 can also be a hollow structure with one side open, and the open side of the second box body 202 covers the open side of the first box body 201, so as to form a box body 20 with a storage space. It is also possible that the first box body 201 is a hollow structure with one side open, and the second box body 202 is a plate-like structure, and the second box body 202 covers the open side of the first box body 201, so as to form a box body 20 with a storage space. The first box body 201 and the second box body 202 can be sealed by a sealing element, and the sealing element can be a sealing ring, a sealant, etc.

[0110] In the battery 100, there may be one or more battery cells 10. If there are more than one battery cell 10, the battery cells 10 may be connected in series, in parallel, or in a mixed connection. A mixed connection means that the battery cells 10 are both connected in series and in parallel. The battery modules may be connected in series, in parallel, or in a mixed connection to form a battery module, and then the battery modules may be connected in series, in parallel, or in a mixed connection to form a whole, and accommodated in the box 20. Alternatively, all the battery cells 10 may be directly connected in series, in parallel, or in a mixed connection, and then the whole formed by all the battery cells 10 may be accommodated in the box 20.

[0111] Please refer to Figure 3 and Figure 4 , Figure 3 An exploded view of a battery cell 10 provided in some embodiments of the present application; Figure 4 for Figure 3 The battery cell 10 is a cross-sectional view of the battery cell 10. The battery cell 10 may include a housing 1 and an electrode assembly 2, wherein the electrode assembly 2 is accommodated in the housing 1.

[0112] In some embodiments, the housing 1 may include a shell 11 and an end cover 12 , wherein the shell 11 has an opening, and the end cover 12 closes the opening of the shell 11 .

[0113] The housing 11 is a component for accommodating the electrode assembly 2. The housing 11 may be a hollow structure with an opening formed at one end, or a hollow structure with openings formed at opposite ends. The housing 11 may be in various shapes, such as a cylindrical shape, a rectangular parallelepiped shape, etc. The housing 11 may be made of various materials, such as copper, iron, aluminum, steel, aluminum alloy, etc.

[0114] The end cap 12 is a component that closes the opening of the shell 11 to isolate the internal environment of the battery cell 10 from the external environment. The end cap 12 and the shell 11 together define a receiving space for accommodating the electrode assembly 2, the electrolyte and other components. The end cap 12 can be connected to the shell 11 by welding or crimping to close the opening of the shell 11. The shape of the end cap 12 can be adapted to the shape of the shell 1. For example, the shell 11 is a rectangular parallelepiped structure, and the end cap 12 is a rectangular plate structure adapted to the shell 1. For another example, the shell 11 is cylindrical, and the end cap 12 is a circular plate structure adapted to the shell 11. The material of the end cap 12 can also be a variety of materials, such as copper, iron, aluminum, steel, aluminum alloy, etc. The material of the end cap 12 and the shell 11 can be the same or different.

[0115] In the embodiment where the housing 11 is opened at one end, one end cap 12 may be provided. In the embodiment where the housing 11 is opened at two opposite ends, two end caps 12 may be provided, and the two end caps 12 respectively close the two openings of the housing 11, and the two end caps 12 and the housing 11 together define a receiving space.

[0116] In some embodiments, the battery cell 10 may further include an electrode terminal 3, which is disposed on the housing 1 and is used to electrically connect to the tab 21 of the electrode assembly 2 to input or output the electrical energy of the battery cell 10. The electrode terminal 3 may be disposed on the shell 11 of the housing 1 or on the end cover 12 of the housing 1. The electrode terminal 3 and the tab 21 may be directly connected, for example, the electrode terminal 3 and the tab 21 are welded. The electrode terminal 3 and the tab 21 may also be indirectly connected, for example, the electrode terminal 3 and the tab 21 are indirectly connected through a current collecting member 4. The current collecting member 4 may be a metal conductor, for example, copper, iron, aluminum, steel, aluminum alloy, etc.

[0117] As an example, in Figure 3 and Figure 4 In the illustrated embodiment, the battery cell 10 is a cylindrical battery cell, the housing 11 is formed with an opening at only one end, there is one end cap 12, the end cap 12 closes the opening of the housing 11, and the electrode terminal 3 is provided on the wall portion of the housing 11 opposite to the end cap 12. The electrode assembly 2 has tabs 21 at opposite ends, the tab 21 at one end of the electrode assembly 2 is a positive tab, and the tab 21 at the other end is a negative tab, the electrode terminal 3 is electrically connected to the positive tab through a current collecting member 4, and the end cap 12 is electrically connected to the negative tab through another current collecting member 4.

[0118] Please refer to Figure 5 and Figure 6 , Figure 5 for Figure 4 A partial enlarged view of the battery cell 10 shown; Figure 6 for Figure 5 The schematic diagram of the structure of the end wall 13 is shown. The embodiment of the present application provides a battery cell 10, and the battery cell 10 includes a shell 1 and an electrode assembly 2. The shell 1 includes an end wall 13 and a side wall 14, the end wall 13 is arranged at one end of the side wall 14 along the first direction X, and the side wall 14 is arranged around the end wall 13. The electrode assembly 2 is accommodated in the shell 1, and the end of the electrode assembly 2 facing the end wall 13 has a pole ear 21, and a first guide channel 6 is formed between the pole ear 21 and the side wall 14. The end wall 13 includes a wall body 131 and a supporting portion 132, the wall body 131 is provided with a pressure relief mechanism 5, and the supporting portion 132 is arranged around the outer edge of the wall body 131. Along the first direction X, the supporting portion 132 protrudes from the wall body 131 in a direction close to the electrode assembly 2, and directly or indirectly abuts against the pole ear 21. The abutting portion 132 and the wall body 131 together define a flow guiding space 133 . The abutting portion 132 is provided with a second flow guiding channel 1321 . The second flow guiding channel 1321 connects the flow guiding space 133 and the first flow guiding channel 6 .

[0119] In the embodiment where the housing 11 is opened at only one end, the end cap 12 may be used as the end wall 13, and the side wall 14 may be a part of the housing 11; or the wall of the housing 11 opposite to the end cap 12 may be used as the end wall 13, and the side wall 14 and the end wall 13 may be integrally formed to form the housing 11. In the embodiment where openings are formed at both opposite ends of the housing 11, at least one of the two end caps 12 may be used as the end wall 13, and the side wall 14 may be the housing 11.

[0120] The side wall 14 may be cylindrical, so that the battery cell 10 is a cylindrical battery cell; the side wall 14 may also be rectangular, so that the battery cell 10 is a square shell battery cell 10 or a blade battery cell 10. The side wall 14 and the end wall 13 may be integrally formed, and the side wall 14 and the end wall 13 constitute the shell 11, and the end of the side wall 14 away from the end wall 13 along the first direction X forms an opening of the shell 11; the side wall 14 and the end wall 13 may also be separately arranged, and the end wall 13 is the end cover 12, and the end of the side wall 14 close to the end wall 13 along the first direction X forms an opening of the shell 11. In the embodiment in which the side wall 14 and the end wall 13 are separately arranged, the end wall 13 and the side wall 14 may be connected by welding, bonding, crimping, etc.

[0121] The electrode assembly 2 may also include a main body, and a pole ear 21 is provided at at least one end of the main body 22 along the first direction X. The first guide channel 6 may be a gap formed between the outer peripheral surface of the pole ear 21 and the inner peripheral surface 141 of the side wall 14. After the electrode assembly 2 is loaded into the shell 1, a gap connected to the first guide channel 6 may also be formed between the outer peripheral surface of the main body 22 and the inner peripheral surface 141 of the side wall 14, and the emissions generated by the thermal runaway of the electrode assembly 2 may enter the first guide channel 6 through the gap. Of course, if the outer peripheral surface of the main body 22 is covered with an insulating film, it may be a gap connected to the first guide gap 6 formed between the outer peripheral surface of the insulating film and the inner peripheral surface 141 of the side wall 14. Among them, the inner peripheral surface 141 of the side wall 14 is the surface of the side wall 14 facing the electrode assembly 2, and the inner peripheral surface 141 may extend along the circumference of the opening of the shell 11 for a whole circle. It can be understood that if the side wall 14 is cylindrical, the inner circumferential surface 141 of the side wall 14 is cylindrical; if the side wall 14 is rectangular, the inner circumferential surface 141 of the side wall 14 is rectangular.

[0122] The wall body 131 and the abutment portion 132 may be integrally formed, or may be separately provided and connected. The pressure relief mechanism 5 may be a pressure relief component separately provided from the wall body 131, and the pressure relief component is installed on the wall body 131. The pressure relief component may be a burst-proof disk, a pressure relief valve, etc. The pressure relief mechanism 5 may also be a structure integrally formed with the wall body 131, for example, the pressure relief mechanism 5 is a weak portion formed on the wall body 131. The weak portion may be formed by providing a groove on the wall body 131, or by heat treating a part of the wall body 131 so that the strength of the local area is weakened to form a corresponding weak portion.

[0123] The abutting portion 132 may be an annular structure surrounding the outer edge of the wall body 131, and the annular structure may be a circular ring structure, a rectangular ring structure, etc. After the abutting portion 132 directly or indirectly abuts against the pole ear 21 of the electrode assembly 2, the abutting portion 132 and the electrode assembly 2 may be electrically connected or insulated, and the pole ear 21 may be a positive pole ear or a negative pole ear. If the abutting portion 132 directly abuts against the pole ear 21 of the electrode assembly 2, the abutting portion 132 is in direct contact with the pole ear 21 of the electrode assembly 2, for example, the abutting portion 132 directly abuts against the pole ear 21 at the end of the electrode assembly 2 to achieve electrical connection between the end wall 13 and the electrode assembly 2; if the abutting portion 132 indirectly abuts against the pole ear 21 of the electrode assembly 2, an intermediate piece is provided between the abutting portion 132 and the electrode assembly 2, and the intermediate piece may be an insulating piece or a conductive piece. Taking the intermediate piece as the current collecting component 4 as an example, the abutting portion 132 may be indirectly abutted against the electrode ear 21 at the end of the electrode assembly 2 through the current collecting component 4 to achieve electrical connection between the end wall 13 and the electrode assembly 2 .

[0124] The flow guiding space 133 defined by the wall body 131 and the abutting portion 132 corresponds to the pressure relief mechanism 5. After the pressure relief mechanism 5 is actuated, the discharge in the flow guiding space 133 can be discharged to the outside of the battery cell 10 through the pressure relief mechanism 5. Along the first direction X, the flow guiding space 133 is formed with an opening at one end of the abutting portion 132 close to the electrode assembly 2. After the abutting portion 132 abuts against the electrode assembly 2 directly or indirectly, the opening is covered. It can be understood that if the abutting portion 132 abuts against the electrode assembly 2 directly, the opening of the flow guiding space 133 is covered by the electrode assembly 2; if the abutting portion 132 abuts against the electrode assembly 2 indirectly through an intermediate piece, the opening of the flow guiding space 133 is covered by the intermediate piece.

[0125] The second guide channel 1321 on the abutting portion 132 may be one or more. If there are more than one second guide channel 1321, the plurality of guide channels may be evenly distributed along the circumferential direction Y of the abutting portion, or may be unevenly distributed along the circumferential direction Y of the abutting portion. The circumferential direction Y of the abutting portion may be the circumferential direction of a circle surrounding a center line extending along the first direction X.

[0126] The second guide channel 1321 can be a through hole that penetrates the abutment portion 132 along the radial direction Z of the abutment portion, or can be a notch that penetrates the abutment portion 132 along the radial direction Z of the abutment portion and extends along the first direction X to one end of the abutment portion 132 close to the electrode assembly 2.

[0127] In the embodiment of the present application, the abutting portion 132 of the end wall 13 directly or indirectly abuts against the pole ear 21 of the electrode assembly 2, and the abutting portion 132 can limit the electrode assembly 2, reducing the risk of the electrode assembly 2 moving in the first direction X in the housing 1. Since the abutting portion 132 is provided with a second guide channel 1321, the second guide channel 1321 connects the guide space 133 and the first guide channel 6. When the battery cell 10 is in thermal runaway, the emission generated by the electrode assembly 2 flows into the first guide channel 6, and the emission can quickly flow into the guide space 133 through the second guide channel 1321 on the abutting portion 132, so that the gas pressure in the guide space 133 is quickly increased to quickly reach the bursting pressure of the pressure relief mechanism 5, shortening the time from the thermal runaway of the battery cell 10 to the pressure relief of the battery cell 10 through the pressure relief mechanism 5, so that the pressure relief mechanism 5 can be actuated in time, reducing the risk of explosion and fire of the battery cell 10, and effectively improving the reliability of the battery cell 10.

[0128] In some embodiments, please refer to Figure 6 The abutting portion 132 is provided with a plurality of second guide channels 1321 , and the plurality of second guide channels 1321 are arranged at intervals along the circumferential direction Y of the abutting portion.

[0129] The number of the second guide channels 1321 on the abutting portion 132 may be two, three, four, five, six or more.

[0130] As an example, the plurality of second guide channels 1321 on the abutting portion 132 are evenly distributed along the circumferential direction Y of the abutting portion, that is, the angles between each two adjacent second guide channels 1321 along the circumferential direction Y of the abutting portion are equal. Taking the number of the second guide channels 1321 on the abutting portion 132 as an example, the distance between each two adjacent second guide channels 1321 along the circumferential direction Y of the abutting portion is 90°.

[0131] In this embodiment, a plurality of second guide channels 1321 are provided on the abutment portion 132 at intervals along the circumferential direction Y of the abutment portion, so that the emissions in the first guide channel 6 can enter the guide space 133 from the plurality of second guide channels 1321 at different positions, thereby increasing the rate at which the emissions in the first guide channel 6 enter the guide space 133, and further shortening the time from thermal runaway of the battery cell 10 to the start of pressure relief of the battery cell 10 through the pressure relief mechanism 5.

[0132] In some embodiments, please refer to Figure 6 Along the first direction X, the abutment portion 132 has a abutment surface 1322, which is the surface of the abutment portion 132 closest to the electrode assembly 2, and the second guide channel 1321 is a notch groove that penetrates the abutment portion 132 along the radial direction Z of the abutment portion and extends along the first direction X to the abutment surface 1322.

[0133] The abutting surface 1322 is not only the surface of the abutting portion 132 closest to the electrode assembly 2, but also the surface of the entire end wall 13 closest to the electrode assembly 2. The radial direction Z of the abutting portion is perpendicular to the first direction X. The notch groove penetrates the abutting portion 132 along the radial direction Z of the abutting portion, so that the second guide channel 1321 connects the guide space 133 and the first guide channel 6. The notch groove extends along the first direction X to the abutting surface 1322, and the notch groove can be formed by being recessed from the abutting surface 1322 in a direction away from the electrode assembly 2, and the notch groove forms a notch on the abutting surface 1322.

[0134] In the embodiment where the abutting portion 132 directly abuts against the pole ear 21 of the electrode assembly 2, the abutting surface 1322 may be in direct contact with the pole ear 21 at the end of the electrode assembly 2, and the pole ear 21 covers the notch formed by the notch groove on the abutting surface 1322; in the embodiment where the abutting portion 132 and the electrode assembly 2 indirectly abut against the electrode assembly 2 via an intermediate piece, the abutting surface 1322 may be in direct contact with the intermediate piece, and the intermediate piece covers the notch formed by the notch groove on the abutting surface 1322.

[0135] In this embodiment, the second guide channel 1321 is a notch groove that penetrates the abutment portion 132 along the radial direction Z of the abutment portion and extends to the abutment surface 1322 along the first direction X. On the one hand, it can reduce the difficulty of forming the second guide channel 1321, and on the other hand, it is beneficial to increase the size of the second guide channel 1321 along the first direction X, thereby increasing the rate at which the discharge in the first guide channel 6 enters the guide space 133 through the second guide channel 1321.

[0136] In some embodiments, please refer to Figure 5 and Figure 6 The abutting portion 132 includes a plurality of protrusions 1323 , which directly or indirectly abut against the electrode tabs 21 of the electrode assembly 2 , and a second guide channel 1321 is formed between two adjacent protrusions 1323 along the circumferential direction Y of the abutting portion.

[0137] The protrusions 1323 in the abutment 132 may be two, three, four, five or more. The number of the second guide channels 1321 and the protrusions 1323 is equal, and along the circumferential direction Y of the abutment, the second guide channels 1321 and the protrusions 1323 are alternately arranged. As an example, the multiple protrusions 1323 in the abutment 132 are evenly distributed along the circumferential direction Y of the abutment, that is, the angles between each two adjacent protrusions 1323 along the circumferential direction Y of the abutment are equal. Taking the example of four protrusions 1323 in the abutment 132, each two adjacent protrusions 1323 along the circumferential direction Y of the abutment are 90° apart.

[0138] The protrusion 1323 is located inside the side wall 14 . The protrusion 1323 may be in contact with the inner surface of the side wall 14 , or there may be a gap between them.

[0139] By forming a second guide channel 1321 between two adjacent protrusions 1323, the discharge in the first guide channel 6 can enter the guide space 133 from multiple second guide channels 1321 at different positions, thereby increasing the rate at which the discharge in the first guide channel 6 enters the guide space 133. In addition, the second guide channel 1321 of this structure is a notch groove formed on the abutting portion 132, which can reduce the difficulty of forming the second guide channel 1321 and is conducive to increasing the size of the second guide channel 1321 along the first direction X.

[0140] In some embodiments, please refer to Figure 7 , Figure 7 for Figure 6 The AA cross-sectional view of the end wall 13 is shown. The protrusion 1323 has abutting surface 1322, which is used to directly or indirectly abut against the electrode ear 21 to achieve electrical connection between the end wall 13 and the electrode assembly 2. Along the first direction X, the height of the protrusion 1323 is H; along the radial direction Z of the abutting portion, the width of the abutting surface 1322 is W; 0.1W≤H≤0.5W.

[0141] In the embodiment where the abutting surface 1322 directly abuts against the pole ear 21 of the electrode assembly 2, the abutting surface 1322 may be in direct contact with the pole ear 21 at the end of the electrode assembly 2 to realize electrical connection between the end wall 13 and the electrode assembly 2; in the embodiment where the abutting surface 1322 and the electrode assembly 2 indirectly abut against the pole ear 21 of the electrode assembly 2 via an intermediate piece, the abutting surface 1322 may be in direct contact with the intermediate piece, the intermediate piece is a conductive piece, and the end wall 13 and the pole ear 21 of the electrode assembly 2 are electrically connected via the intermediate piece.

[0142] The height of the protrusion 1323 is equal to the depth of the notch groove (the second guide channel 1321 ).

[0143] It can be understood that 0.1≤H / W≤0.5, and H / W can be any point value among 0.1, 0.12, 0.15, 0.18, 0.2, 0.22, 0.25, 0.28, 0.3, 0.32, 0.35, 0.38, 0.4, 0.42, 0.45, 0.48, 0.5, or a range value between any two of them.

[0144] By directly or indirectly abutting the abutting surface 1322 against the pole ear 21 of the electrode assembly 2, the end wall 13 and the electrode assembly 2 can be electrically connected. In order to achieve stable flow between the end wall 13 and the electrode assembly 2, the abutting surface 1322 generally has a certain width. Therefore, the height of the protrusion 1323 is controlled within the range of 0.1W to 0.5W. This can not only ensure that the size of the second guide channel 1321 along the first direction X meets the flow requirement, so that the discharge in the first guide channel 6 can quickly enter the guide space 133 through the second guide channel 1321, but also reduce the influence of the excessive height of the protrusion 1323 on the volume energy density of the battery cell 10.

[0145] In some embodiments, along the first direction X, the height of the protrusion 1323 is H, and 5 mm ≥ H ≥ 0.5 mm.

[0146] H can be any point value among 0.5mm, 0.8mm, 1mm, 1.2mm, 1.5mm, 1.8mm, 2mm, 2.2mm, 2.5mm, 2.8mm, 3mm, 3.2mm, 3.5mm, 3.8mm, 4mm, 4.2mm, 4.5mm, 4.8mm, 5mm, or a range value between any two of them.

[0147] In this embodiment, H≥0.5mm, so that the size of the second flow guiding channel 1321 along the first direction X is greater than or equal to 0.5mm, so that the size of the second flow guiding channel 1321 along the first direction X meets the flow requirement, so that the discharge in the first flow guiding channel 6 can quickly enter the flow guiding space 133 through the second flow guiding channel 1321; H≤5mm, so that the height of the protrusion 1323 is not too large, reducing the space occupied by the protrusion 1323 in the housing 1 along the first direction X, which is conducive to improving the volume energy density of the battery cell 10. In this way, the flow requirement of the second flow guiding channel 1321 and the volume energy density requirement of the battery cell 10 are taken into account.

[0148] In some embodiments, please refer to Figure 8 , Figure 8 for Figure 7 The end wall 13 is shown in the B direction view. Along the circumferential direction Y of the abutment portion, the protrusion 1323 has a first end 13231 and a second end 13232 opposite to each other. The projection of the outer edge of the end wall 13 along the first direction X forms a first circle Q. When viewed along the first direction X, the line connecting the first end 13231 and the center of the first circle Q is the first line U, and the line connecting the second end 13232 and the center of the first circle Q is the second line V. The angle between the first line U and the second line V is α, 15°≤α≤60°.

[0149] The angle between the first connecting line U and the second connecting line V is the central angle of the protrusion 1323 . The first connecting line U and the second connecting line V are both straight lines.

[0150] α can take any point value among 15°, 20°, 25°, 30°, 35°, 40°, 45°, 50°, 55°, 60° or any range value between two of them.

[0151] By controlling α between 15° and 60°, more protrusions 1323 can be provided along the circumferential direction Y of the abutment portion to form more second guide channels 1321 , so that the discharge in the first guide channel 6 can enter the guide space 133 from more positions.

[0152] In some embodiments, please refer to Figure 8 , along the circumferential direction Y of the abutting portion, a plurality of protrusions 1323 are evenly arranged.

[0153] It can be understood that along the circumferential direction Y of the abutment portion, the angle between each two adjacent protrusions 1323 is equal, and the angle between each two adjacent protrusions 1323 is β=360° / N, where N is the number of protrusions 1323. Figure 8 In the illustrated embodiment, N=4 and β=90°.

[0154] In this embodiment, multiple protrusions 1323 are evenly arranged along the circumferential direction Y of the abutment portion, so that multiple second guide channels 1321 on the abutment portion 132 can be evenly arranged along the circumferential direction Y of the abutment portion, so that the emissions in the second guide channels 1321 can more evenly enter the guide space 133 from the multiple guide channels, further improving the rate at which the emissions in the first guide channel 6 enter the guide space 133.

[0155] In some embodiments, please refer to Fig. 9 and Fig.10 , Fig. 9 A partial enlarged view of a battery cell 10 provided in some other embodiments of the present application; Fig.10 for Fig. 9 A partial enlarged view of the center C. Along the radial direction Z of the abutting portion, a flow guiding gap 7 is formed between the side wall 14 and the protruding portion 1323. The flow guiding gap 7 communicates with two adjacent second flow guiding channels 1321.

[0156] The flow guide gap 7 is formed between the inner circumferential surface 141 of the side wall 14 and the surface of the protrusion 1323 facing the inner circumferential surface 141 of the side wall 14. The protrusion 1323 may not contact the inner circumferential surface 141 of the side wall 14 to form the flow guide gap 7 between the protrusion 1323 and the side wall 14, or a part of the protrusion 1323 may contact the inner circumferential surface 141 of the side wall 14, and the other part may not contact the inner circumferential surface 141 of the side wall 14 to form the flow guide gap 7 between the protrusion 1323 and the side wall 14.

[0157] The guide gap 7 between the side wall 14 and the protrusion 1323 can connect two adjacent second guide channels 1321. When the emissions in the first guide channel 6 flow toward one of the second guide channels 1321, the emissions can flow toward another adjacent second guide channel 1321 through the guide gap 7, so that the emissions in the first guide channel 6 can enter the guide space 133 more quickly.

[0158] For example, when the battery cell 10 is in thermal runaway, if the thermal runaway area of ​​the electrode assembly 2 is close to a second guide channel 1321, the emissions generated by the thermal runaway of the electrode assembly 2 will flow concentratedly to the second guide channel 1321. When the second guide channel 1321 is unable to guide the emissions into the guide space 133 in time, the emissions that have not entered the guide space 133 in time can flow to another adjacent second guide channel 1321 through the guide gap 7, and then quickly enter the guide space 133.

[0159] In some embodiments, please refer to Figure 10-12 , Fig.11 for Fig. 9 The schematic structural diagram of the end wall 13 shown; Fig.12 for Fig.11 DD cross-sectional view of the end wall 13 shown. The abutment portion 132 also includes a body portion 1324, which is arranged around the outer edge of the wall body 131 and protrudes from the wall body 131 in a direction close to the electrode assembly 2. Along the first direction X, the body portion 1324 has a first surface 13241 facing the electrode assembly 2, and the protrusion 1323 is arranged on the first surface 13241.

[0160] The body portion 1324 may be an annular structure surrounding the outer edge of the wall body 131. The first surface 13241 may be the surface of the body portion 1324 closest to the electrode assembly 2 along the first direction X. The protrusion 1323 is disposed on the first surface 13241, so that the protrusion 1323 extends from the first surface 13241 in a direction close to the electrode assembly 2. The second guide channel 1321 between two adjacent protrusions 1323 is a notch groove, and the groove bottom surface of the notch groove is located on the first surface 13241.

[0161] The main body 1324 and the wall body 131 can be formed as one piece; the main body 1324 and the wall body 131 can also be set separately and connected to each other, and the connection method between the two can be welding, bonding, etc.; the protrusion 1323 and the main body 1324 can be formed as one piece; the protrusion 1323 and the main body 1324 can also be set separately and connected to each other, and the connection method between the two can be welding, bonding, etc.

[0162] In this embodiment, the main body 1324 serves to connect the wall body 131 and the protruding portion 1323 . The main body 1324 is arranged around the wall body 131 and protrudes from the wall body 131 in a direction close to the electrode assembly 2 , which can effectively improve the deformation resistance of the end wall 13 .

[0163] In some embodiments, please refer to Figure 10-12 Along the first direction X, the wall body 131 has a second surface 1311 , which is the surface of the wall body 131 closest to the electrode assembly 2 , and the first surface 13241 is closer to the electrode assembly 2 than the second surface 1311 .

[0164] Along the first direction X, the wall body 131 has a sixth surface 1313 facing the electrode assembly 2, the body portion 1324 extends from the sixth surface 1313 toward the electrode assembly 2, and the second surface 1311 and the sixth surface 1313 can be the same surface or different surfaces. Fig.12 In the illustrated embodiment, the second surface 1311 and the sixth surface 1313 are different surfaces. Along the first direction X, the second surface 1311 is closer to the electrode assembly 2 than the sixth surface 1313 .

[0165] In this embodiment, the first surface 13241 is closer to the electrode assembly 2 than the second surface 1311, which can increase the distance between the second surface 1311 and the electrode assembly 2, reduce the impact of the electrode assembly 2 on the pressure relief mechanism 5 on the wall body 131, and effectively increase the size of the guide space 133 along the first direction X.

[0166] In some embodiments, please refer to Fig.10 , the abutting portion 132 is provided with a first groove 1325. Along the first direction X, the body portion 1324 has a third surface 13242 arranged opposite to the first surface 13241, the first surface 13241 is closer to the electrode assembly 2 than the third surface 13242, and the first groove 1325 is recessed from the third surface 13242 toward the direction close to the electrode assembly 2, so as to form a protrusion 1323 protruding from the first surface 13241 on the side of the body portion 1324 facing the electrode assembly 2.

[0167] The first groove 1325 corresponds to the protrusion 1323 one by one. The first groove 1325 can be formed on the abutting portion 132 by stamping. By stamping the first groove 1325 on the third surface 13242, the protrusion 1323 protruding from the first surface 13241 of the main body 1324 can be formed correspondingly, so that the protrusion 1323 and the main body 1324 are integrally formed. The first groove 1325 can be a primary groove, and the first groove 1325 can be formed by only one stamping during the processing; the first groove 1325 can also be a multi-stage groove, and the multi-stage groove can be formed step by step by multiple stampings during the processing.

[0168] By providing the first groove 1325 on the abutting portion 132 to form the protruding portion 1323 accordingly, the difficulty of forming the protruding portion 1323 can be effectively reduced, and the weight of the end wall 13 can be effectively reduced.

[0169] In some embodiments, please refer to Fig.10 The first groove 1325 is a multi-level groove. Along the first direction X, the first-level groove close to the electrode assembly 2 of the adjacent two-level grooves is arranged on the groove bottom surface of the first-level groove away from the electrode assembly 2.

[0170] It is understood that the first groove 1325 is a stepped groove. The first groove 1325 can be a two-level groove, a three-level groove, a four-level groove, a five-level groove, etc. As an example, in Fig.10 In the illustrated embodiment, the first groove 1325 is a two-stage groove.

[0171] By configuring the first groove 1325 as a multi-stage groove, the forming force applied to the end wall 13 when forming each stage of the groove is lower, thereby reducing the risk of the end wall 13 being damaged due to excessive forming force when forming the first groove 1325 .

[0172] In some embodiments, the protrusion 1323 includes a first portion 13233 and a second portion 13234, and the multi-stage groove includes a first-stage groove 13251 and a second-stage groove 13252. The first-stage groove 13251 is recessed from the third surface 13242 in a direction close to the electrode assembly 2 to form a first portion 13233 protruding from the first surface 13241 on the side of the body portion 1324 facing the electrode assembly 2, and along the first direction X, the first portion 13233 has a fourth surface 13233a facing the electrode assembly 2. The second-stage groove 13252 is recessed from the groove bottom surface of the first-stage groove 13251 in a direction close to the electrode assembly 2 to form a second portion 13234 protruding from the fourth surface 13233a on the side of the first portion 13233 facing the electrode assembly 2.

[0173] It should be noted that the protrusion 1323 may include only the first part 13233 and the second part 13234, or may include other parts except the first part 13233 and the second part 13234. If the protrusion 1323 includes only the first part 13233 and the second part 13234, along the first direction, the sum of the heights of the first part 13233 and the second part 13234 is equal to the height H of the protrusion 1323. The multi-stage groove may include only the first-stage groove 13251 and the second-stage groove 13252, or may include other-stage grooves except the first-stage groove 13251 and the second-stage groove 13252. Taking the multi-stage groove including only the first-stage groove 13251 and the second-stage groove 13252 as an example, the first-stage groove 13251 and the second-stage groove 13252 can be stamped. During molding, a first-level groove 13251 can be punched out on the third surface 13242 to form a first part 13233 protruding from the first surface 13241; and then a second-level groove 13252 can be punched out on the bottom surface of the first-level groove 13251 to form a second part 13234 of the fourth surface 13233a protruding from the first part 13233, and finally the first groove 1325 and the protrusion 1323 are formed.

[0174] The first portion 13233 and the second portion 13234 are both located inside the side wall 14. The first portion 13233 may contact the inner surface of the side wall 14 or have a gap therebetween. The second portion 13234 may contact the inner surface of the side wall 14 or have a gap therebetween.

[0175] In this embodiment, by setting a first-level groove 13251 on the main body 1324, the first part 13233 of the protrusion 1323 can be formed accordingly, and by setting a second-level groove 13252 on the first part 13233, the second part 13234 of the protrusion 1323 can be formed accordingly, which can reduce the difficulty of molding the protrusion 1323.

[0176] In some embodiments, please refer to Fig.10 Along the radial direction Z of the abutment portion, the first portion 13233 has a first side surface 13233b facing the inner circumferential surface 141 of the side wall 14, and the second portion 13234 has a second side surface 13234a facing the inner circumferential surface 141 of the side wall 14. The first side surface 13233b is closer to the inner circumferential surface 141 of the side wall 14 than the second side surface 13234a. A guide gap 7 is formed between the second side surface 13234a and the inner circumferential surface 141 of the side wall 14, and the guide gap 7 connects two adjacent second guide channels 1321.

[0177] A flow guide gap 7 is formed between the second side surface 13234a and the inner peripheral surface 141 of the side wall 14, that is, the second side surface 13234a does not contact the inner peripheral surface 141 of the side wall 14. Of course, a flow guide gap 7 may also be formed between the first side surface 13233b and the inner peripheral surface 141 of the side wall 14, or they may directly contact each other.

[0178] As an example, the first side surface 13233 b and the second side surface 13234 a are arc surfaces whose central axes extend along the first direction X, and the central axes of the first side surface 13233 b and the second side surface 13234 a coincide with the central axis of the inner circumferential surface 141 of the side wall 14 .

[0179] In this embodiment, the guide gap 7 between the second side surface 13234a and the inner circumferential surface 141 of the side wall 14 can connect two adjacent second guide channels 1321. When the emissions in the first guide channel 6 flow toward one of the second guide channels 1321, the emissions can flow toward another adjacent second guide channel 1321 through the guide gap 7, so that the emissions in the first guide channel 6 can enter the guide space 133 more quickly.

[0180] In some embodiments, please refer to Fig.10 A second groove 134 is provided at a position corresponding to the main body 1324 on one side of the end wall 13 away from the electrode assembly 2 , and the third surface 13242 is the bottom surface of the second groove 134 .

[0181] As an example, the second groove 134 and the main body 1324 have the same shape, both of which are annular structures.

[0182] The second groove 134 can be formed in the end wall 13 by stamping. If the second groove 134 is stamped on one side of the end wall 13, the body 1324 can be formed correspondingly on the other side of the end wall 13, so that the wall body 131 and the body 1324 are integrally formed. During the molding, the second groove 134 can be stamped on the end wall 13 first, and then the first groove 1325 can be stamped on the bottom surface of the second groove 134.

[0183] In this embodiment, the main body 1324 is formed correspondingly by providing the second groove 134 on the end wall 13 , which can effectively reduce the difficulty of forming the main body 1324 .

[0184] In some embodiments, please refer to Fig.10 The end wall 13 and the side wall 14 are separately arranged, and at least a portion of the main body 1324 is accommodated in the side wall 14 and forms a positioning fit with the side wall 14.

[0185] The end wall 13 and the side wall 14 are arranged separately, that is, the end wall 13 and the side wall 14 are two parts that are not formed in one piece. As an example, the end wall 13 is the end cover 12 in the housing 1, and the end wall 13 and the side wall 14 are connected by welding.

[0186] The portion of the body 1324 received in the side wall 14 forms a positioning fit with the side wall 14, so that the outer circumference of the body 1324 is in contact with the inner circumference 141 of the side wall 14. As an example, the portion of the body 1324 received in the side wall 14 forms an interference fit with the side wall 14.

[0187] In this embodiment, the main body 1324 and the side wall 14 form a positioning match, which can effectively improve the assembly difficulty of the end wall 13 and the side wall 14. Taking the welding connection of the end wall 13 and the side wall 14 as an example, during the assembly process, after the main body 1324 and the side wall 14 form a positioning match, the end wall 13 and the side wall 14 can be more easily welded together, reducing the welding difficulty of the two and improving the welding quality of the two.

[0188] In some embodiments, please refer to Fig.10 The end wall 13 further includes an edge portion 135 , which is disposed around the outer edge of the main body portion 1324 , and the edge portion 135 abuts against one end of the side wall 14 along a direction of the end wall 13 pointing toward the electrode assembly 2 .

[0189] The edge portion 135 is an annular structure surrounding the outer edge of the main body portion 1324. The outer edge of the edge portion 135 is the outer edge of the end wall 13.

[0190] As an example, the side wall 14 is a part of the outer shell 1 , and an opening is formed at only one end of the outer shell 1 along the first direction X. The edge portion 135 abuts against the end of the outer shell 1 forming the opening along the direction of the end wall 13 pointing to the electrode assembly 2 , and the edge portion 135 is welded to the side wall 14 .

[0191] In this embodiment, the edge portion 135 abuts against the side wall 14 to limit the end wall 13 and restrict the end wall 13 from moving in a direction close to the electrode assembly 2 .

[0192] In some embodiments, the wall body 131 and the abutting portion 132 are integrally formed.

[0193] As an example, a second groove 134 is provided at a position corresponding to the abutting portion 132 on a side of the end wall 13 facing away from the electrode assembly 2 , and the second groove 134 is formed by stamping.

[0194] In the embodiment where the end wall 13 further includes an edge portion 135 , the edge portion 135 , the abutting portion 132 and the wall body 131 may be integrally formed.

[0195] In this embodiment, the wall body 131 and the abutting portion 132 are integrally formed, which can effectively improve the connection strength between the abutting portion 132 and the wall body 131 .

[0196] In some embodiments, please refer to Fig.12 , along the first direction X, the wall body 131 has a fifth surface 1312, the fifth surface 1312 is the surface of the end wall 13 farthest from the electrode assembly 2, and the pressure relief mechanism 5 is closer to the electrode assembly 2 than the fifth surface 1312 ( Fig.12 not shown).

[0197] The fifth surface 1312 may be an end surface of the battery cell 10 at one end along the first direction X. The fifth surface 1312 is used to contact with an external component. In an embodiment in which the end wall 13 is electrically connected to the electrode assembly 2, the end wall 13 serves as an output pole of the battery cell 10, and the external component may be a busbar component for being electrically connected to the end wall 13; in an embodiment in which the end wall 13 is insulated from the electrode assembly 2, the end wall 13 may be a component located in the bottom area of ​​the battery cell 10, and the external component may be the case 20 in the battery 100. After the battery cell 10 is placed in the case 20, the fifth surface 1312 may serve as the lower end surface of the battery cell 10 in contact with the case 20.

[0198] It should be noted that, in the present embodiment, the pressure relief mechanism 5 may be a pressure relief component that is separately provided from the wall body 131 , or the pressure relief mechanism 5 may be a structure that is integrally formed with the wall body 131 .

[0199] In this embodiment, the pressure relief mechanism 5 is closer to the electrode assembly 2 than the fifth surface 1312, which increases the distance between the pressure relief mechanism 5 and the external component when the fifth surface 1312 contacts the external component, reduces the impact of the external component on the pressure relief mechanism 5, and reduces the risk of premature actuation of the pressure relief mechanism 5 due to the impact force of the external component.

[0200] In some embodiments, please refer to Fig.12 The wall body 131 is provided with a third groove 1314, and the third groove 1314 is recessed from the fifth surface 1312 toward the direction close to the electrode assembly 2. The bottom wall 13141 of the third groove is provided with a pressure relief groove 1316 to form a pressure relief mechanism 5 at a position corresponding to the bottom wall 13141 of the third groove and the pressure relief groove 1316.

[0201] The third groove 1314 can be stamped and formed on the wall body 131. The projection of the third groove 1314 along the first direction X can be rectangular, circular, elliptical, etc. The groove bottom wall 13141 of the third groove is the part of the wall body 131 located at the bottom of the third groove 1314 along the depth direction of the third groove 1314.

[0202] The pressure relief groove 1316 can be arranged on a side of the groove bottom wall 13141 of the third groove facing the electrode assembly 2 , or can be arranged on a side of the groove bottom wall 13141 of the third groove away from the electrode assembly 2 .

[0203] By providing the pressure relief groove 1316 on the groove bottom wall 13141 of the third groove, a corresponding pressure relief mechanism 5 is formed integrally with the wall body 131. The pressure relief mechanism 5 is the groove bottom wall of the pressure relief groove 1316, and the groove bottom wall of the pressure relief groove 1316 is the portion of the groove bottom wall 13141 of the third groove located at the bottom of the pressure relief groove 1316 along the depth direction of the pressure relief groove 1316.

[0204] As an example, Fig.12 As shown, a concave portion is provided on the side of the bottom wall 13141 of the third groove facing away from the electrode assembly 2, and a reinforcing rib 1315 is formed at a position corresponding to the concave portion on the side of the bottom wall 13141 of the third groove facing the electrode assembly 2. The reinforcing rib 1315 is roughly X-shaped. Along the first direction X, the surface of the end of the reinforcing rib 1315 facing the electrode assembly 2 is the surface of the wall body 131 closest to the electrode assembly 2 (the second surface 1311). The pressure relief groove 1316 is an annular groove, which surrounds the outside of the reinforcing rib 1315. The pressure relief groove 1316 defines a pressure relief zone, and the reinforcing rib 1315 is located in the pressure relief zone. When the battery cell 10 is depressurized, the wall body 131 will split along the pressure relief groove 1316, thereby opening the pressure relief zone. The reinforcing rib 1315 is used to strengthen the pressure relief zone, improve the deformation resistance of the pressure relief zone, and reduce the risk of the pressure relief mechanism 5 being deformed due to changes in the internal pressure of the battery cell 10, resulting in premature rupture due to fatigue.

[0205] In this embodiment, by setting a third groove 1314 that is recessed from the fifth surface 1312 toward the electrode assembly 2 on the wall body 131, and setting a pressure relief groove 1316 on the bottom wall 13141 of the third groove to form a corresponding pressure relief mechanism 5, the pressure relief mechanism 5 is closer to the electrode assembly 2 than the fifth surface 1312, and the implementation method is simple.

[0206] In some embodiments, the wall body 131 is provided with a pressure relief groove 1316 to form a pressure relief mechanism 5 at a position of the wall body 131 corresponding to the pressure relief groove 1316 .

[0207] There are many ways to form the pressure relief groove 1316, such as stamping, laser etching, milling, etc. The pressure relief groove 1316 can be a groove extending along a closed track, which can be a circular track, a rectangular track, etc. The pressure relief groove 1316 can also be a groove extending along a non-closed track, which can be an H-shaped track, a V-shaped track, a C-shaped track, a Y-shaped track, etc.

[0208] By providing the pressure relief groove 1316 on the wall body 131 , an integrated pressure relief mechanism 5 is formed accordingly. The molding method of the pressure relief mechanism 5 is simple, and the reliability of the pressure relief mechanism 5 is higher.

[0209] In some embodiments, please refer to Fig. 9 The battery cell 10 may further include a current collecting member 4, which is disposed between the end wall 13 and the electrode assembly 2 along the first direction X, the current collecting member 4 electrically connects the electrode assembly 2 and the end wall 13, the abutting portion 132 directly abuts against the current collecting member 4, and the current collecting member 4 directly abuts against the pole ear 21.

[0210] The current collecting member 4 is a conductive member for realizing electrical connection between the electrode assembly 2 and the end wall 13. The current collecting member 4 is located in the housing 1 and between the end wall 13 and the electrode assembly 2. The current collecting member 4 can be welded to the pole ear 21 at the end of the electrode assembly 2, and the current collecting member 4 can also be welded to the abutment portion 132.

[0211] In this embodiment, the abutting portion 132 indirectly abuts against the electrode lug 21 of the electrode assembly 2 through the current collecting component 4. The current collecting component 4 can realize electrical connection between the electrode assembly 2 and the end wall 13, thereby reducing the difficulty of electrical connection between the electrode assembly 2 and the end wall 13.

[0212] In some embodiments, the electrode assembly 2 is provided with a first central hole 23 , and the current collecting member 4 is provided with a second central hole 41 , and the second central hole 41 communicates with the first central hole 23 and the flow guiding space 133 .

[0213] As an example, the electrode assembly 2 is a winding structure, and the first center hole 23 is located at the winding center of the winding structure. The first center hole 23 and the second center hole 41 are both cylindrical holes, the first center hole 23 and the second center hole 41 are coaxially arranged, and the aperture of the first center hole 23 is larger than the aperture of the second center hole 41.

[0214] When the battery cell 10 thermally runs away, the emissions generated by the electrode assembly 2 can enter the guide space 133 through the first center hole 23 and the second center hole 41 in sequence, further shortening the time from the thermal runaway of the battery cell 10 to the pressure relief of the battery cell 10 through the pressure relief mechanism 5, so that the pressure relief mechanism 5 can be actuated more timely.

[0215] In some embodiments, the housing 1 includes a shell 11 and an end cap 12. The shell 11 is formed with an opening at at least one end along the first direction X, and the end cap 12 closes the opening. At least one end cap 12 is an end wall 13, and the shell 11 includes a side wall 14.

[0216] The shell 11 may have an opening formed at only one end along the first direction X, and one end cap 12 is provided accordingly. The shell 11 may have openings formed at both ends along the first direction X, and two end caps 12 are provided accordingly, and the two end caps 12 respectively close the two opposite openings of the shell 11, and one end cap 12 may be the end wall 13, or both end caps 12 may be the end wall 13. It can be understood that the end wall 13 and the side wall 14 are provided separately.

[0217] In this embodiment, at least one end cover 12 is an end wall 13, so that at least one end cover 12 is provided with a pressure relief mechanism 5, which reduces the difficulty of molding or installing the pressure relief mechanism 5, and enables the second guide channel 1321 to be provided on the end cover 12, which reduces the difficulty of molding the second guide channel 1321.

[0218] In some embodiments, the battery cell 10 is a cylindrical battery cell.

[0219] It can be understood that the battery cell 10 is cylindrical, and the axial direction of the battery cell 10 is parallel to the first direction X.

[0220] An embodiment of the present application provides a battery 100, comprising a battery cell 10 provided in any one of the above embodiments.

[0221] An embodiment of the present application further provides an electrical device, comprising the battery cell 10 improved according to any one of the above embodiments, wherein the battery cell 10 is used to provide electrical energy to the electrical device.

[0222] In addition, please refer to Figure 3-Figure 7 The embodiment of the present application also provides a cylindrical battery cell, including a shell 1, an electrode assembly 2 and a current collecting member 4, wherein the electrode assembly 2 and the current collecting member 4 are both contained in the shell 1. The shell 1 includes a shell 11 and an end cover 12, wherein the shell 11 has an opening formed at only one end along a first direction X, and the end cover 12 closes the opening, and the first direction X is parallel to the axial direction of the shell 1. The electrode assembly 2 includes a main body 22 and a tab 21, wherein tabs 21 are provided at both ends of the main body 22 along the first direction X, and the tabs 21 at both ends of the main body 22 are respectively a positive tab and a negative tab. The wall of the shell 11 opposite to the end cover 12 is provided with an electrode terminal 3, wherein the electrode terminal 3 is electrically connected to the positive tab through a current collecting member 4, and the end cover 12 is electrically connected to the negative tab through another current collecting member 4.

[0223] The end cap 12 is the end wall 13 of the outer shell 1, the shell 11 includes a side wall 14 surrounding the end wall 13, and a first flow guide channel 6 is formed between the negative pole ear of the electrode assembly 2 and the side wall 14. The end wall 13 includes a wall body 131 and a support portion 132, the wall body 131 is provided with a pressure relief groove 1316, so as to form a pressure relief mechanism 5 at a position corresponding to the wall body 131 and the pressure relief groove 1316, and the support portion 132 is arranged around the outer edge of the wall body 131. Along the first direction X, the support portion 132 protrudes from the wall body 131 in a direction close to the electrode assembly 2 and directly abuts against the current collecting member 4. The support portion 132 and the wall body 131 jointly define a flow guide space 133, and the support portion 132 is provided with a second flow guide channel 1321, and the second flow guide channel 1321 connects the flow guide space 133 and the first flow guide channel 6.

[0224] The abutting portion 132 includes a body portion 1324 and a plurality of protrusions 1323. The body portion 1324 is arranged around the outer edge of the wall body 131 and protrudes from the wall body 131 in a direction close to the electrode assembly 2. In the first direction X, the body portion 1324 has a first surface 13241 facing the electrode assembly 2. The protrusions 1323 are arranged on the first surface 13241. The protrusions 1323 directly abut against the current collecting member 4. A second groove 134 is arranged at a position corresponding to the body portion 1324 on the side of the end wall 13 facing away from the electrode assembly 2. The abutting portion 132 is provided with a first groove 1325. In the first direction X, the first groove 1325 is recessed from the groove bottom surface of the second groove 134 in a direction close to the electrode assembly 2, so as to form a protrusion 1323 protruding from the first surface 13241 on the side of the body portion 1324 facing the electrode assembly 2. The plurality of protrusions 1323 are evenly distributed along the circumferential direction Y of the abutting portion, and a second flow guide channel 1321 is formed between two adjacent protrusions 1323. Along the first direction X, the height of the protrusion 1323 is H; the protrusion 1323 has an abutting surface 1322 that directly abuts against the current collecting member 4, and along the radial direction Z of the abutting portion, the width of the abutting surface 1322 is W; 0.1W≤H≤0.5W, 5mm≥H≥0.5mm.

[0225] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application may be combined with each other.

[0226] The above embodiments are only used to illustrate the technical solution of the present application and are not used to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A battery cell, characterized in that: include: The housing comprises an end wall and a side wall, wherein the end wall is arranged at one end of the side wall along a first direction, and the side wall is arranged around the end wall; An electrode assembly is contained in the housing, wherein one end of the electrode assembly facing the end wall has an electrode ear, and a first flow guide channel is formed between the electrode ear and the side wall; In which, the end wall includes a wall body and a supporting portion, the wall body is provided with a pressure relief mechanism, and the supporting portion is arranged around the outer edge of the wall body; along the first direction, the supporting portion protrudes from the wall body in a direction close to the electrode assembly, and directly or indirectly abuts against the pole ear; the supporting portion and the wall body jointly define a guide space, and the supporting portion is provided with a second guide channel, and the second guide channel connects the guide space and the first guide channel.

2. The battery cell according to claim 1, characterized in that: The abutting portion is provided with a plurality of the second flow guiding channels, and the plurality of the second flow guiding channels are arranged at intervals along the circumferential direction of the abutting portion.

3. The battery cell according to claim 1, characterized in that: Along the first direction, the abutment portion has a abutment surface, which is the surface of the abutment portion closest to the electrode assembly, and the second guide channel is a notch groove that penetrates the abutment portion radially and extends to the abutment surface along the first direction.

4. The battery cell according to claim 1, characterized in that: The abutting portion comprises: A plurality of protrusions are directly or indirectly pressed against the pole lug, and a second flow guide channel is formed between two adjacent protrusions along the circumference of the pressing portion.

5. The battery cell according to claim 4, characterized in that: The protrusion has a contact surface, and the contact surface is used to directly or indirectly contact the electrode ear to achieve electrical connection between the end wall and the electrode assembly; Along the first direction, the height of the protruding portion is H; along the radial direction of the abutting portion, the width of the abutting surface is W; 0.1W≤H≤0.5W.

6. The battery cell according to claim 4, characterized in that: Along the first direction, the height of the protrusion is H, 5mm≥H≥0.5mm.

7. The battery cell according to claim 4, characterized in that: Along the circumference of the abutting portion, the protrusion has a first end and a second end opposite to each other; The projection of the outer edge of the end wall along the first direction forms a first circle. When observed along the first direction, the line connecting the first end and the center of the first circle is a first line, and the line connecting the second end and the center of the first circle is a second line. The angle between the first line and the second line is α, and 15°≤α≤60°.

8. The battery cell according to claim 4, characterized in that: Along the circumference of the abutting portion, a plurality of the protrusions are evenly arranged.

9. The battery cell according to claim 4, characterized in that: A flow guiding gap is formed between the side wall and the protruding portion along the radial direction of the abutting portion; and the flow guiding gap communicates with two adjacent second flow guiding channels.

10. The battery cell according to claim 4, characterized in that: The abutting portion further comprises: The main body is arranged around the outer edge of the wall body and protrudes from the wall body in a direction close to the electrode assembly. Along the first direction, the main body has a first surface facing the electrode assembly, and the protrusion is arranged on the first surface.

11. The battery cell according to claim 10, characterized in that: Along the first direction, the wall body has a second surface, the second surface is a surface of the wall body closest to the electrode assembly, and the first surface is closer to the electrode assembly than the second surface.

12. The battery cell according to claim 10, characterized in that: The abutment portion is provided with a first groove; along the first direction, the main body portion has a third surface arranged opposite to the first surface, the first surface is closer to the electrode assembly than the third surface, and the first groove is recessed from the third surface toward the direction close to the electrode assembly to form the protrusion protruding from the first surface on the side of the main body portion facing the electrode assembly.

13. The battery cell according to claim 12, characterized in that: The first groove is a multi-level groove. Along the first direction, a first-level groove close to the electrode assembly in two adjacent levels of grooves is arranged on a groove bottom surface of a first-level groove away from the electrode assembly.

14. The battery cell according to claim 13, characterized in that: The protrusion includes a first part and a second part, and the multi-stage groove includes: A first-level groove is recessed from the third surface toward the electrode assembly to form the first portion protruding from the first surface on the side of the body portion facing the electrode assembly, and the first portion has a fourth surface facing the electrode assembly along the first direction; The second-stage groove is recessed from the groove bottom surface of the first-stage groove toward the direction close to the electrode assembly to form the second portion protruding from the fourth surface on the side of the first portion facing the electrode assembly.

15. The battery cell according to claim 14, characterized in that: Along the radial direction of the abutment portion, the first part has a first side surface facing the inner circumferential surface of the side wall, and the second part has a second side surface facing the inner circumferential surface of the side wall, the first side surface is closer to the inner circumferential surface of the side wall than the second side surface, and a guide gap is formed between the second side surface and the inner circumferential surface of the side wall, and the guide gap connects two adjacent second guide channels.

16. The battery cell according to claim 12, characterized in that: A second groove is provided at a position corresponding to the main body on a side of the end wall away from the electrode assembly, and the third surface is a groove bottom surface of the second groove.

17. The battery cell according to claim 10, characterized in that: The end wall and the side wall are separately arranged, and at least a part of the main body is accommodated in the side wall and forms a positioning fit with the side wall.

18. The battery cell according to claim 17, characterized in that: The end wall further includes an edge portion, which is disposed around the outer edge of the main body portion, and the edge portion abuts against one end of the side wall along a direction from the end wall to the electrode assembly.

19. The battery cell according to any one of claims 1 to 18, characterized in that: The wall body and the abutting portion are integrally formed.

20. The battery cell according to any one of claims 1 to 18, characterized in that: Along the first direction, the wall body has a fifth surface, the fifth surface is the surface of the end wall farthest from the electrode assembly, and the pressure relief mechanism is closer to the electrode assembly than the fifth surface.

21. The battery cell according to claim 20, characterized in that The wall body is provided with a third groove, and the third groove is recessed from the fifth surface toward the direction close to the electrode assembly. The bottom wall of the third groove is provided with a pressure relief groove to form the pressure relief mechanism at a position where the bottom wall of the third groove corresponds to the pressure relief groove.

22. The battery cell according to any one of claims 1 to 18, characterized in that: The wall body is provided with a pressure relief groove, so that the pressure relief mechanism is formed at a position of the wall body corresponding to the pressure relief groove.

23. The battery cell according to any one of claims 1 to 18, characterized in that: The battery cell further comprises: A current collecting member is disposed between the end wall and the electrode assembly along the first direction, the current collecting member electrically connects the electrode assembly and the end wall, the abutting portion directly abuts against the current collecting member, and the current collecting member directly abuts against the electrode lug.

24. The battery cell according to claim 23, characterized in that: The electrode assembly is provided with a first central hole, and the current collecting member is provided with a second central hole, and the second central hole communicates with the first central hole and the flow guiding space.

25. The battery cell according to any one of claims 1 to 18, characterized in that: The housing comprises: A housing, at least one end of which is formed with an opening along the first direction; an end cap for closing the opening; Wherein, at least one end cover is the end wall, and the shell includes the side wall.

26. The battery cell according to any one of claims 1 to 18, characterized in that: The battery cell is a cylindrical battery cell.

27. A battery, characterized in that: Comprising the battery cell according to any one of claims 1-26.

28. An electrical equipment, characterized in that: The invention comprises a battery cell as claimed in any one of claims 1 to 26, wherein the battery cell is used to provide electrical energy to the electrical device.

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