Battery monomer, battery device and electric device

Abstract

The utility model provides a battery cell, a battery device and a power utilization device. The single battery comprises an electrode assembly and a shell, the shell comprises a first wall, a second wall and a side wall, the first wall and the second wall are arranged at the two ends of the side wall in the first direction respectively, and the side wall surrounds the electrode assembly. The first wall comprises a body part and an abutting part, and the body part is provided with a pressure relief mechanism. The body part is provided with a first surface and a second surface which are oppositely arranged; the first surface is the surface farthest from the second wall of the first wall; the abutting part is arranged on the outer edge of the body part in a surrounding mode and protrudes out of the second surface. The abutting part is provided with an abutting face closest to the second wall, and the abutting face abuts against the electrode assembly. The abutting face is provided with a flow guide groove, and the flow guide groove penetrates through the inner circumferential face of the abutting portion and the outer circumferential face of the abutting portion. In the first direction, the abutting part is provided with a third surface opposite to the groove bottom face of the flow guide groove, and the distance between the groove bottom face of the flow guide groove and the third surface is smaller than the distance between the first surface and the second surface. And the energy density of the single battery is relatively high.

Description

Technical Field

[0001] This application relates to the field of batteries, and more specifically, to a battery cell, a battery device, and an electrical device. Background Technology

[0002] Batteries are widely used in the new energy field, such as in electric vehicles and new energy vehicles, which have become a new trend in the automotive industry. The development of battery technology must consider multiple design factors simultaneously, such as cycle life, discharge capacity, and charge / discharge rate. Additionally, battery energy density also needs to be considered. However, the energy density of current batteries is relatively low. Utility Model Content

[0003] The purpose of this application is to provide a battery cell, a battery device, and an electrical device, which aims to improve the problem of low energy density of batteries in related technologies.

[0004] In a first aspect, embodiments of this application provide a battery cell, the battery cell including an electrode assembly and a housing, the housing accommodating the electrode assembly, the housing including a first wall, a second wall and a side wall, the first wall and the second wall respectively disposed at both ends of the side wall along a first direction, the side wall surrounding the electrode assembly; wherein, the first wall includes a body portion and an abutment portion, the body portion being provided with a pressure relief mechanism, the body portion having a first surface and a second surface disposed opposite to each other, the first surface being the surface of the first wall furthest from the second wall, the abutment portion being disposed around the outer edge of the body portion and protruding from the second surface, the abutment portion having an abutment surface closest to the second wall, the abutment surface directly or indirectly abutting against the electrode assembly, the abutment surface being provided with a guide groove, the guide groove penetrating the inner and outer peripheral surfaces of the abutment portion along the width direction of the abutment portion, along the first direction, the abutment portion having a third surface disposed opposite to the bottom surface of the guide groove, the distance between the bottom surface of the guide groove and the third surface being less than the distance between the first surface and the second surface.

[0005] In the above technical solution, the first wall includes abutting portion, the abutting surface of which directly or indirectly abuts against the electrode assembly. The abutting portion can restrict the electrode assembly, reducing the risk of the electrode assembly moving along the first direction within the casing. Since the abutting portion is provided with a guide channel penetrating both the inner and outer circumferential surfaces of the abutting portion, when a battery cell experiences thermal runaway, the discharge outside the abutting portion can flow through the guide channel to the pressure relief mechanism, thereby facilitating rapid actuation of the pressure relief mechanism. This shortens the time from battery cell thermal runaway to the start of pressure relief by the pressure relief mechanism, reducing the risk of battery cell explosion and fire, and effectively improving the reliability of the battery cell. By making the distance between the bottom surface of the guide channel and the third surface smaller than the distance between the first and second surfaces—that is, by thinning the portion of the abutting portion located between the bottom surface of the guide channel and the third surface—the height of the abutting portion protruding from the second surface can be reduced while maintaining the same depth of the guide channel. This allows for a reduction in the size of the first wall along the first direction, providing more space for the electrode assembly and improving the energy density of the battery cell.

[0006] As an optional technical solution in this application embodiment, along the first direction, the distance between the bottom surface of the guide channel and the third surface is H1, and the distance between the first surface and the second surface is H2, satisfying: 0.5≤H1 / H2<1, and optionally, 0.6≤H1 / H2≤0.8.

[0007] In the above technical solution, when H1 / H2 < 1, along the first direction, the distance between the bottom surface of the guide channel and the third surface is less than the distance between the first surface and the second surface. This means the portion of the abutment located between the bottom surface of the guide channel and the third surface is thinned. Thus, while keeping the depth of the guide channel constant, the height of the abutment protruding from the second surface can be reduced, allowing the dimension of the first wall along the first direction to be reduced. This provides more space for electrode components, which is beneficial for improving the energy density of the battery cell. When H1 / H2 ≥ 0.5, the distance between the bottom surface of the guide channel and the third surface is not too small, ensuring that the portion of the abutment located between the bottom surface of the guide channel and the third surface is not too thin. This provides sufficient strength to reduce the risk of deformation or breakage of the portion of the abutment located between the bottom surface of the guide channel and the third surface, which is beneficial for improving the reliability of the battery cell. Therefore, when 0.5 ≤ H1 / H2 < 1, both the reliability and energy density of the battery cell can be balanced.

[0008] When H1 / H2 ≤ 0.8, the distance between the bottom surface of the guide channel and the third surface is small along the first direction. This means that the thinning of the portion of the abutment located between the bottom surface of the guide channel and the third surface is greater. With the depth of the guide channel remaining constant, the height of the abutment protruding from the second surface can be further reduced, allowing for a further reduction in the dimension of the first wall along the first direction. This provides more space for electrode components, which is more conducive to improving the energy density of the battery cell. When H1 / H2 ≥ 0.6, the distance between the bottom surface of the guide channel and the third surface is not too small, ensuring that the portion of the abutment located between the bottom surface of the guide channel and the third surface is not too thin. This provides sufficient strength for the portion of the abutment located between the bottom surface of the guide channel and the third surface, reducing the risk of deformation and breakage, and improving the reliability of the battery cell. Therefore, when 0.6 ≤ H1 / H2 ≤ 0.8, a better balance between the reliability and energy density of the battery cell can be achieved.

[0009] As an optional technical solution in this application embodiment, along the first direction, the distance between the bottom surface of the guide channel and the third surface is H1, which satisfies: 0.18mm≤H1≤1.5mm, and optionally, 0.3mm≤H1≤0.5mm.

[0010] In the above technical solution, when H1 ≤ 1.5 mm, the distance between the bottom surface of the guide channel and the third surface is small along the first direction, which helps to reduce the size of the first wall along the first direction, thereby allowing more space to be placed for electrode components and improving the energy density of the battery cell. When H1 ≥ 0.18 mm, the distance between the bottom surface of the guide channel and the third surface is not too small, ensuring that the portion of the abutment located between the bottom surface of the guide channel and the third surface is not too thin. This provides sufficient strength to reduce the risk of deformation or breakage of the portion of the abutment located between the bottom surface of the guide channel and the third surface, thus improving the reliability of the battery cell. Therefore, when 0.18 mm ≤ H1 ≤ 1.5 mm, both the reliability and energy density of the battery cell can be balanced.

[0011] When H1 ≤ 0.5 mm, the distance between the bottom surface of the guide channel and the third surface is smaller along the first direction, which is more conducive to reducing the size of the first wall along the first direction, thereby allowing more space to be placed for electrode components and improving the energy density of the battery cell. When H1 ≥ 0.3 mm, the distance between the bottom surface of the guide channel and the third surface is not too small, ensuring that the portion of the abutment located between the bottom surface of the guide channel and the third surface is not too thin. This provides sufficient strength to reduce the risk of deformation or breakage of the portion of the abutment located between the bottom surface of the guide channel and the third surface, thus improving the reliability of the battery cell. Therefore, when 0.3 mm ≤ H1 ≤ 0.5 mm, both the reliability and energy density of the battery cell can be balanced.

[0012] As an optional technical solution in this application embodiment, the distance between the first surface and the second surface along the first direction is H2, which satisfies: 0.3mm≤H2≤2.5mm, and optionally, 0.45mm≤H2≤0.8mm.

[0013] In the above technical solution, when H2 ≥ 0.3 mm, the distance between the first surface and the second surface along the first direction is relatively large, ensuring that the portion of the body located between the first and second surfaces has sufficient thickness and strength. This helps reduce the risk of deformation and breakage of the body and improves the reliability of the battery cell. When H2 ≤ 2.5 mm, the distance between the first surface and the second surface along the first direction is not too large. On the one hand, this helps reduce the size of the first wall along the first direction, allowing more space to be placed for electrode components, which helps improve the energy density of the battery cell. On the other hand, it helps reduce the material used in the first wall, thereby reducing the manufacturing cost of the battery cell. Therefore, when 0.3 mm ≤ H2 ≤ 2.5 mm, both the reliability and energy density of the battery cell can be balanced.

[0014] When H2 ≥ 0.45 mm, the distance between the first and second surfaces along the first direction is greater, resulting in a thicker portion of the body between the first and second surfaces. This portion of the body has better strength, reducing the risk of deformation and breakage, and improving the reliability of the battery cell. When H2 ≤ 0.8 mm, the distance between the first and second surfaces along the first direction is not too large. On the one hand, this allows for a smaller dimension of the first wall along the first direction, providing more space for electrode components and improving the energy density of the battery cell. On the other hand, it reduces the material used in the first wall, thus lowering the manufacturing cost of the battery cell. Therefore, when 0.45 mm ≤ H2 ≤ 0.8 mm, both the reliability and energy density of the battery cell can be balanced.

[0015] As an optional technical solution in this application embodiment, along the first direction, the distance between the abutment surface and the bottom surface of the guide channel is H3, which satisfies: 0.2mm≤H3≤1.8mm, and optionally, 0.4mm≤H3≤1.6mm.

[0016] In the above technical solution, when H3 ≥ 0.2 mm, the distance between the contact surface and the bottom surface of the guide channel along the first direction is relatively large, and the depth of the guide channel is relatively large. This facilitates the flow of waste material from the outside of the contact part to the pressure relief mechanism through the guide channel, shortening the time from the thermal runaway of the battery cell to the start of pressure relief by the pressure relief mechanism, which is beneficial to improving the timeliness of pressure relief of the battery cell and improving its reliability. When H3 ≤ 1.8 mm, the distance between the contact surface and the bottom surface of the guide channel along the first direction is not too large, and the depth of the guide channel is not too deep, which is beneficial to reducing the size of the first wall along the first direction and improving the energy density of the battery cell. Therefore, when 0.2 mm ≤ H3 ≤ 1.8 mm, both the reliability and energy density of the battery cell can be balanced.

[0017] When H3 ≥ 0.4 mm, the distance between the contact surface and the bottom surface of the guide channel along the first direction is greater, and the depth of the guide channel is greater. This facilitates the flow of waste material from the outside of the contact area to the pressure relief mechanism through the guide channel, shortening the time from thermal runaway of the battery cell to the start of pressure relief by the mechanism. This improves the timeliness of pressure relief and the reliability of the battery cell. When H3 ≤ 1.6 mm, the distance between the contact surface and the bottom surface of the guide channel along the first direction is not too large, and the depth of the guide channel is not too deep. This helps to reduce the size of the first wall along the first direction, which is beneficial to improving the energy density of the battery cell. Therefore, when 0.4 mm ≤ H3 ≤ 1.6 mm, it is possible to better balance the reliability and energy density of the battery cell.

[0018] As an optional technical solution in this application embodiment, along the first direction, the third surface is closer to the second wall than the second surface.

[0019] In the above technical solution, by making the third surface closer to the second wall than the second surface, it is beneficial to reduce the risk of external force acting on the part of the abutment located between the bottom surface of the guide channel and the third surface, thereby reducing the risk of deformation and breakage of the part of the abutment located between the bottom surface of the guide channel and the third surface, which is beneficial to improving the reliability of the battery cell.

[0020] As an optional technical solution in this application embodiment, the hardness of the portion of the abutment located between the bottom surface of the guide channel and the third surface is greater than the hardness of the portion of the body located between the first surface and the second surface.

[0021] In the above technical solution, the hardness of the part of the abutment located between the bottom surface and the third surface of the guide channel is greater than the hardness of the part of the main body located between the first surface and the second surface. During manufacturing, the bottom wall of the guide channel can be thinned by forming methods such as stamping and cold heading, which is simple and convenient to manufacture and has a low cost.

[0022] As an optional technical solution in this application embodiment, the abutting part includes a first part and a first transition part. The first part is the bottom wall of the guide channel, the surface of the first part facing away from the second wall is the third surface, the first transition part connects the first part and the body part, and the thickness of the first transition part is greater than the thickness of the first part.

[0023] In the above technical solution, during manufacturing, the bottom wall of the guide channel can be thinned by forming methods such as stamping and cold heading. During the processing, the bottom wall of the guide channel will squeeze material towards the first transition part, thereby increasing the thickness of the first transition part, making the thickness of the first transition part greater than the thickness of the first part.

[0024] As an optional technical solution in this application embodiment, the first wall further includes an edge portion, which is disposed around the outer edge of the abutment portion. Along the first direction, the abutment surface is closer to the second wall than the edge portion. The edge portion is located on the side of the side wall away from the second wall and is connected to the side wall.

[0025] In the above technical solution, the first wall also includes an edge portion, which abuts against the side wall to limit the movement of the first wall in the direction close to the electrode assembly.

[0026] As an optional technical solution in this application embodiment, the abutment part includes a first part and a second transition part. The first part is the bottom wall of the guide channel, the surface of the first part facing away from the second wall is the third surface, the second transition part connects the first part and the edge part, and the thickness of the second transition part is greater than the thickness of the first part.

[0027] In the above technical solution, during manufacturing, the bottom wall of the guide channel can be thinned by forming methods such as stamping and cold heading. During the processing, the bottom wall of the guide channel will squeeze material towards the second transition part, thereby increasing the thickness of the second transition part, making the thickness of the second transition part greater than the thickness of the first part.

[0028] As an optional technical solution in this application embodiment, a first flow channel is formed between the sidewall and the electrode assembly, and the first flow channel is connected to the guide groove.

[0029] In the above technical solution, by connecting the first flow channel and the guide groove, when the battery cell experiences thermal runaway, the discharge from the first flow channel can flow to the pressure relief mechanism through the guide groove, thereby facilitating the rapid activation of the pressure relief mechanism. This shortens the time from the battery cell's thermal runaway to the battery cell starting to depressurize through the pressure relief mechanism, reduces the risk of battery cell explosion and fire, and effectively improves the reliability of the battery cell.

[0030] As an optional technical solution in this application embodiment, the body part includes a second part and a third part. The second part connects the third part and the abutment part. Along the first direction, the third part protrudes from the second part in a direction close to the second wall. The pressure relief mechanism is disposed on the third part. The surface of the second part away from the second wall is the first surface.

[0031] In the above technical solution, the third part protrudes from the second part along the direction close to the second wall. The pressure relief mechanism is set in the third part, which increases the distance between the pressure relief mechanism and the external component when the first surface contacts the external component, reduces the influence of the external component on the pressure relief mechanism, and reduces the risk of the pressure relief mechanism being prematurely activated by the impact force of the external component.

[0032] As an optional technical solution in this application embodiment, the outer shell includes a housing and an end cap. One end of the housing has an opening, and the end cap closes the opening. The end cap is the first wall, and along a first direction, the wall portion of the housing opposite to the end cap is the second wall.

[0033] In the above technical solution, when the end cap is the first wall, the pressure relief mechanism is set in the end cap, which is simple and convenient to manufacture.

[0034] Secondly, embodiments of this application also provide a battery device, which includes the aforementioned battery cell.

[0035] Thirdly, embodiments of this application also provide an electrical device, which includes the aforementioned battery cell, and the battery cell is used to provide electrical energy to the electrical device. Attached Figure Description

[0036] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0037] Figure 1This application provides structural schematic diagrams of vehicles for some embodiments;

[0038] Figure 2 Exploded views of battery devices provided in some embodiments of this application;

[0039] Figure 3 Exploded views of a single battery cell provided in some embodiments of this application;

[0040] Figure 4 Cross-sectional views of a battery cell provided in some embodiments of this application;

[0041] Figure 5 A schematic diagram of the structure of the first wall provided for some embodiments of this application;

[0042] Figure 6 A top view of the first wall provided for some embodiments of this application;

[0043] Figure 7 for Figure 6 A cross-sectional view at position AA.

[0044] Icons: 10-Box body; 11-First box body; 12-Second box body; 20-Battery cell; 21-Outer shell; 211-Shell; 2111-Side wall; 2112-Second wall; 2113-First flow channel; 212-End cap; 213-First wall; 2131-Abutting part; 21311-Abutting surface; 21312-Guide channel; 21313-Channel bottom wall; 21314-Channel bottom surface; 21315-Third surface; 21316-First part; 2132-Body part; 2132 1-First surface; 21322-Second surface; 2133-First transition portion; 2134-Second transition portion; 2135-Edge portion; 2136-Second part; 21361-First groove; 2137-Third part; 22-Electrode assembly; 221-Main body; 222-Electrode tab; 23-Current collector; 24-Electrode terminal; 25-Pressure relief mechanism; 251-Weak part; 252-Pressure relief groove; 100-Battery device; 200-Controller; 300-Motor; 1000-Vehicle. Detailed Implementation

[0045] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0046] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used in the description of this application is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms "comprising" and "having," and any variations thereof, in the description, claims, and accompanying drawings of this application are intended to cover non-exclusive inclusion. The terms "first," "second," etc., in the description, claims, or accompanying drawings of this application are used to distinguish different objects, not to describe a specific order or hierarchy.

[0047] In this application, the reference to "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment that is mutually exclusive with other embodiments.

[0048] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "attachment" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0049] In this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, in this application, the character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0050] In the embodiments of this application, the same reference numerals denote 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 this application shown in the accompanying drawings, as well as the overall thickness, length, width, and other dimensions of the integrated device, are merely illustrative and should not constitute any limitation on this application.

[0051] In this application, "multiple" means two or more (including two).

[0052] In this embodiment of the application, the battery cell can be a secondary battery, which refers to a battery cell that can be recharged to activate the active materials and continue to be used after the battery cell has been discharged.

[0053] 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-metal hydride batteries, nickel-cadmium batteries, lead-acid batteries, etc.

[0054] A single battery cell typically includes an electrode assembly. The electrode assembly includes a positive electrode, a negative electrode, and a separator. During the charging and discharging process of a single battery cell, active ions (such as lithium ions) repeatedly insert and extract between the positive and negative electrodes. The separator, positioned between the positive and negative electrodes, reduces the risk of short circuits while allowing active ions to pass through.

[0055] In some embodiments, the positive electrode may be a positive electrode sheet, which 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.

[0056] As an example, the positive current collector has two surfaces opposite each other in its own thickness direction, and the positive active material is disposed on either or both of the two opposite surfaces of the positive current collector.

[0057] As an example, the positive electrode current collector can be a metal foil or a composite current collector. For example, as a metal foil, it can be 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. Composite current collectors can include a polymer material base layer and a metal layer. Composite current collectors can 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.).

[0058] As an example, the positive electrode active material may include at least one of the following materials: lithium phosphate, lithium transition metal oxide, and their respective modified compounds. However, this application is not limited to these materials, and other conventional materials that can be used as positive electrode active materials in battery cells may also be used. These positive electrode active materials may be used alone or in combination of two or more. Examples of lithium phosphate may include, but are not limited to, at least one of lithium iron phosphate (such as LiFePO4 (also referred to as LFP)), lithium iron phosphate and carbon composites, lithium manganese phosphate (such as LiMnPO4), lithium manganese phosphate and carbon composites, lithium iron manganese phosphate, and lithium iron manganese phosphate and carbon composites. Examples of lithium transition metal oxide 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, and lithium nickel cobalt manganese oxide (such as LiNi). 1 / 3 Co 1 / 3Mn 1 / 3O2 (also known as NCM) 333 LiNi 0.5 Co 0.2 Mn 0.3 O2 (also known as NCM) 523 LiNi 0.5 Co 0.25 Mn 0.25 O2 (also known as NCM) 211 LiNi 0.6 Co 0.2 Mn 0.2 O2 (also known as NCM) 622 LiNi 0.8 Co 0.1 Mn 0.1 O2 (also known as NCM) 811 ), lithium nickel cobalt aluminum oxide (such as LiNi) 0.85 Co 0.15 Al 0.05 At least one of O2 and its modified compounds.

[0059] In some embodiments, the positive electrode can be a foamed metal. The foamed metal can be foamed nickel, foamed copper, foamed aluminum, foamed alloys, etc. When foamed metal is used as the positive electrode, the surface of the foamed metal may or may not contain a positive electrode active material. As an example, lithium source material, potassium metal, or sodium metal can also be filled and / or deposited within the foamed metal, where the lithium source material is lithium metal and / or a lithium-rich material.

[0060] In some embodiments, the negative electrode may be a negative electrode sheet, and the negative electrode sheet may include a negative electrode current collector.

[0061] As an example, the negative electrode current collector can be a metal foil, a foamed metal, or a composite current collector. For example, as a metal foil, it can be aluminum with a silver-plated surface, stainless steel with a silver-plated surface, stainless steel, copper, aluminum, nickel, carbon electrodes, carbon, nickel, or titanium, etc. Foamed metal can be nickel foam, copper foam, aluminum foam, foam alloy, etc. Composite current collectors can include a polymer material base layer and a metal layer. Composite current collectors can 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.).

[0062] 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.

[0063] As an example, the negative electrode current collector has two surfaces opposite each other in its own thickness direction, and the negative electrode active material is disposed on either or both of the two opposite surfaces of the negative electrode current collector.

[0064] As an example, the negative electrode active material may be a negative electrode active material known in the art for use in battery cells. 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, and lithium titanate, etc. Silicon-based materials may be selected from at least one of elemental silicon, silicon oxide compounds, silicon-carbon composites, silicon-nitrogen composites, and silicon alloys. Tin-based materials may be selected from at least one of elemental tin, tin oxide compounds, and tin alloys. However, this application is not limited to these materials, and other conventional materials that can be used as negative electrode active materials in battery cells may also be used. These negative electrode active materials may be used alone or in combination of two or more.

[0065] In some embodiments, the positive current collector can be made of aluminum, and the negative current collector can be made of copper.

[0066] In some embodiments, the separator is a separator membrane. The separator membrane can be any known porous structure separator membrane with good chemical and mechanical stability.

[0067] As an example, the material of the separator may include at least one of glass fiber, nonwoven 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 it may be attached to the surfaces of the positive and negative electrodes.

[0068] In some embodiments, the battery cell also includes an electrolyte, which acts as a conductor of ions between the positive and negative electrodes. The electrolyte can be liquid, gel-like, or solid. Liquid electrolytes include electrolyte salts and solvents.

[0069] In some embodiments, the electrolyte salt may include at least one of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium hexafluoroarsenate, lithium bis(fluorosulfonyl)imide, lithium bis(trifluoromethanesulfonyl)imide, lithium trifluoromethanesulfonate, lithium difluorophosphate, lithium difluorooxalate borate, lithium dioxalate borate, lithium difluorodioxalate phosphate, and lithium tetrafluorooxalate phosphate.

[0070] In some embodiments, the solvent may include at least one selected from ethylene carbonate, propylene carbonate, methyl ethyl carbonate, diethyl carbonate, dimethyl carbonate, dipropyl carbonate, methyl propyl carbonate, ethyl propyl carbonate, butyl carbonate, fluoroethylene carbonate, methyl formate, methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, propyl propionate, methyl butyrate, ethyl butyrate, 1,4-butyrolactone, sulfolane, dimethyl sulfone, methyl ethyl sulfone, and diethyl sulfone. The solvent may also be an ether solvent. Ether solvents may include one or more selected from ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, 1,3-dioxolane, tetrahydrofuran, methyl tetrahydrofuran, diphenyl ether, and crown ethers.

[0071] Among them, the gel electrolyte includes a polymer as the electrolyte backbone network, combined with an ionic liquid - lithium salt.

[0072] In some implementations, the electrode assembly is a wound structure. The positive and negative electrode sheets are wound into a wound structure.

[0073] In some implementations, the electrode assembly is a stacked structure.

[0074] As an example, multiple positive and negative electrodes can be set, and multiple positive and multiple negative electrodes can be stacked alternately.

[0075] As an example, multiple positive electrode plates can be provided, and negative electrode plates can be folded to form multiple stacked folded segments, with a positive electrode plate sandwiched between adjacent folded segments.

[0076] As an example, both the positive and negative electrode plates are folded to form multiple stacked folded segments.

[0077] As an example, multiple separators can be provided, each positioned between any adjacent positive or negative electrode plates.

[0078] As an example, the separators can be continuously arranged, either by folding or rolling between any adjacent positive or negative electrode plates.

[0079] In some implementations, the electrode assembly may be flat or polygonal in shape.

[0080] In some embodiments, the electrode assembly has tabs that allow current to be drawn from the electrode assembly. The tabs include a positive tab and a negative tab.

[0081] In some embodiments, the battery cell may include a housing. The housing is used to encapsulate components such as electrode assemblies and electrolytes. The housing may be made of steel, aluminum, or a composite metal (such as a copper-aluminum composite housing).

[0082] In some embodiments, the housing can be a sealed structure or a non-sealed structure. As an example, when the housing is a sealed structure, it can protect the electrode assembly and prevent, to some extent, electrolyte leakage. When the housing is a non-sealed structure, it can still protect the electrode assembly, and a sealing bag may be included between the housing and the electrode assembly to encapsulate the electrode assembly and electrolyte. Specifically, the sealing bag can be a bag-shaped insulating component or an aluminum-plastic film.

[0083] As an example, a battery cell can be a prismatic battery cell or a battery cell of other shapes. Prismatic battery cells include prismatic battery cells, blade-shaped battery cells, and multi-prismatic battery cells, such as hexagonal prismatic battery cells.

[0084] The battery device mentioned in the embodiments of this application may include one or more battery cell assemblies for providing voltage and capacity. A battery cell assembly may include multiple battery cells, which are connected in series, parallel, or mixed connections via a busbar.

[0085] In some embodiments, a battery cell assembly is typically formed by arranging multiple battery cells; as an example, a battery cell assembly can be a battery module, which is formed by arranging multiple battery cells and fixing them together to form an independent module.

[0086] As an example, a battery module can be formed by bundling multiple battery cells together with cable ties.

[0087] In some embodiments, the battery device may be a battery pack, which may include a housing and one or more individual battery cell assemblies housed within the housing.

[0088] As an example, the battery cell assembly can be a battery module, and the battery cell assembly can be housed in the housing by fixing the battery module in the housing.

[0089] As an example, battery cell assemblies can also be housed in a housing by directly fixing multiple battery cells to the housing.

[0090] As an example, the enclosure may include a first enclosure body and a second enclosure body. The first enclosure body and the second enclosure body are fastened together to form a closed space inside the enclosure to house the individual battery cells. Here, "closed" refers to covering or closing, which can be either sealed or unsealed. The first enclosure body may be a top cover or a bottom plate.

[0091] As an example, the enclosure may include a top cover, a frame, and a bottom plate. The top cover and bottom plate are connected to the frame, creating an enclosed space inside the enclosure to house the individual battery cells.

[0092] As an example, the housing can be part of the vehicle's chassis structure. For instance, the housing's roof can be at least part of the vehicle's floor, or the housing's frame can be at least part of the vehicle's crossbeams and longitudinal beams.

[0093] In some embodiments, the battery device refers to an energy storage device, which includes a housing with a door on at least one side. Energy storage devices include energy storage containers, energy storage cabinets, etc.

[0094] Currently, judging from market trends, battery applications are becoming increasingly widespread. Batteries are not only used in energy storage systems such as hydropower, thermal power, wind power, and solar power plants, but also extensively in electric vehicles such as electric bicycles, electric motorcycles, and electric cars, as well as in military equipment and aerospace. With the continuous expansion of battery applications, market demand is also constantly increasing.

[0095] The development of battery technology must consider multiple design factors simultaneously, such as cycle life, discharge capacity, and charge / discharge rate. Additionally, battery energy density also needs to be considered. However, the energy density of current batteries is relatively low.

[0096] In some embodiments, to improve the reliability of a battery cell, a pressure relief mechanism can generally be provided on the end cap of the battery cell's casing. In the event of thermal runaway of the battery cell, the pressure inside the battery cell can be released through the pressure relief mechanism.

[0097] A pressure relief mechanism is a component or part that is activated to release internal pressure when the internal pressure of a battery cell reaches a predetermined threshold. This threshold design varies depending on design requirements. The threshold may depend on the materials of one or more of the components in the battery cell: the positive electrode, the negative electrode, the electrolyte, and the separator.

[0098] The term "actuation" as used in this application refers to the activation or actuation of the pressure relief mechanism to a certain state, thereby releasing the internal pressure of the battery cell. The actions of the pressure relief mechanism may include, but are not limited to, at least a portion of the mechanism rupturing, breaking, tearing, or opening. When the pressure relief mechanism is actuated, the high-temperature, high-pressure substances inside the battery cell are discharged as waste from the actuated portion. This method allows for pressure relief of the battery cell under controlled pressure, thereby preventing potentially more serious accidents.

[0099] The emissions from battery cells mentioned in the embodiments of this application include, but are not limited to: electrolyte, dissolved or split positive and negative electrode plates, fragments of the separator, high-temperature and high-pressure gases generated by the reaction, flames, etc.

[0100] In a typical battery cell, a protruding abutment is formed on the end wall of the casing where a pressure relief mechanism is located, protruding towards the electrode assembly. This abutment directly or indirectly abuts against the electrode assembly to reduce the movement of the electrode assembly within the casing. However, because the abutment directly or indirectly abuts against the electrode assembly, in the event of thermal runaway of the battery cell, the discharged material outside the abutment may not reach the area where the pressure relief mechanism is located on the end wall. The pressure relief mechanism may not be activated in time, posing a risk of battery cell explosion and fire, thus affecting the reliability of the battery cell.

[0101] To address the issue of poor reliability in individual battery cells, a flow channel can be incorporated into the contact area, penetrating both its outer and inner circumferential surfaces. This allows waste material from the outside of the contact area to flow through the channel to the pressure relief mechanism, facilitating its rapid activation. However, achieving sufficient depth in the flow channel increases the thickness of the end walls, reducing the space available for electrode components and resulting in lower energy density in the individual battery cells.

[0102] In view of this, embodiments of this application provide a battery cell, which includes an electrode assembly and a housing, the housing accommodating the electrode assembly. The housing includes a first wall, a second wall, and a side wall, the first wall and the second wall being respectively disposed at both ends of the side wall along a first direction, the side wall surrounding the electrode assembly. The first wall includes a body portion and abutment portion, the body portion being provided with a pressure relief mechanism. The body portion has a first surface and a second surface disposed opposite to each other, the first surface being the surface of the first wall furthest from the second wall, the abutment portion being disposed around the outer edge of the body portion and protruding from the second surface. The abutment portion has an abutment surface closest to the second wall, the abutment surface directly or indirectly abutting against the electrode assembly. The abutment surface is provided with a guide groove, the guide groove penetrating the inner and outer peripheral surfaces of the abutment portion along the width direction. Along the first direction, the abutment portion has a third surface disposed opposite to the bottom surface of the guide groove, the distance between the bottom surface of the guide groove and the third surface being less than the distance between the first surface and the second surface.

[0103] The first wall includes abutment portion, the abutment surface of which directly or indirectly abuts against the electrode assembly. The abutment portion restricts the electrode assembly, reducing the risk of it moving within the casing along the first direction. Because the abutment portion has a guide channel penetrating both its inner and outer circumferential surfaces, when a battery cell experiences thermal runaway, the discharge outside the abutment portion can flow through the guide channel to the pressure relief mechanism. This facilitates rapid activation of the pressure relief mechanism, shortening the time from thermal runaway to the start of pressure relief by the mechanism, reducing the risk of battery cell explosion and fire, and effectively improving battery cell reliability. By making the distance between the bottom surface of the guide channel and the third surface smaller than the distance between the first and second surfaces—that is, by thinning the portion of the abutment portion between the bottom surface of the guide channel and the third surface—the height of the abutment portion protruding from the second surface can be reduced while maintaining the same depth of the guide channel. This allows for a reduction in the size of the first wall along the first direction, providing more space for the electrode assembly and improving the energy density of the battery cell.

[0104] The technical solutions described in the embodiments of this application are applicable to various electrical devices that use battery cells and battery devices, such as mobile phones, portable devices, laptops, electric vehicles, electric toys, power tools, vehicles, ships and spacecraft, etc. For example, spacecraft include airplanes, rockets, space shuttles and spacecraft.

[0105] For ease of explanation, the following embodiments will use a vehicle as an example of an electrical device.

[0106] Please refer to Figure 1 , Figure 1 This is a schematic diagram of the structure of a vehicle 1000 provided in some embodiments of this application. A battery device 100 is disposed inside the vehicle 1000, and the battery device 100 may be located at the bottom, front, or rear of the vehicle 1000. The battery device 100 can be used to power the vehicle 1000; for example, the battery device 100 can serve as the operating power source for the vehicle 1000.

[0107] The vehicle 1000 may also include a controller 200 and a motor 300. The controller 200 is used to control the battery device 100 to supply power to the motor 300, for example, for the power needs of the vehicle 1000 during startup, navigation and driving.

[0108] In some embodiments of this application, the battery device 100 can not only serve as the operating power source for the vehicle 1000, but also as the driving power source for the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0109] Please refer to Figure 2 , Figure 2This is an exploded view of a battery device 100 provided in some embodiments of this application. The battery device 100 may include a housing 10 and battery cells 20, the housing 10 being used to house the battery cells 20.

[0110] The housing 10 has an enclosed space inside for accommodating the battery cells 20. The housing 10 can have various structures. In some embodiments, the housing 10 may include a first housing body 11 and a second housing body 12, which are interlocked. The first housing body 11 and the second housing body 12 can have various shapes, such as cuboids or cylinders. The first housing body 11 can be a hollow structure open on one side, and the second housing body 12 can also be a hollow structure open on one side. The open side of the second housing body 12 interlocks with the open side of the first housing body 11, thus forming a housing 10 with an enclosed space. Alternatively, the first housing body 11 can be a hollow structure open on one side, and the second housing body 12 can be a plate-like structure, with the second housing body 12 interlocked with the open side of the first housing body 11, thus forming a housing 10 with an accommodating chamber.

[0111] In the battery device 100, there can be one or more battery cells 20. If there are multiple battery cells 20, they can be connected in series, parallel, or in a mixed configuration. A mixed configuration means that multiple battery cells 20 are connected in both series and parallel. Alternatively, multiple battery cells 20 can be first connected in series, parallel, or in a mixed configuration to form a battery module, and then multiple battery modules can be connected in series, parallel, or in a mixed configuration to form a whole, which is then housed within the housing 10. Another option is that all battery cells 20 can be directly connected in series, parallel, or in a mixed configuration, and then the whole consisting of all battery cells 20 is housed within the housing 10.

[0112] In some embodiments, the battery device 100 may further include a busbar component, through which multiple battery cells 20 can be electrically connected to each other to achieve series, parallel, or mixed connection of the multiple battery cells 20. The busbar component may be a metallic conductor, such as copper, iron, aluminum, stainless steel, aluminum alloy, etc.

[0113] Please refer to Figure 3 , Figure 4 , Figure 5 , Figure 6 and Figure 7 , Figure 3 An exploded view of a battery cell 20 provided in some embodiments of this application. Figure 4 A cross-sectional view of a battery cell 20 provided for some embodiments of this application. Figure 5 This is a structural schematic diagram of the first wall 213 provided for some embodiments of this application. Figure 6 This is a top view of the first wall 213 provided for some embodiments of this application. Figure 7 for Figure 6A cross-sectional view at position AA. This application provides a battery cell 20, which includes an electrode assembly 22 and a housing 21. The housing 21 accommodates the electrode assembly 22. The housing 21 includes a first wall 213, a second wall 2112, and a side wall 2111. The first wall 213 and the second wall 2112 are respectively disposed at both ends of the side wall 2111 along a first direction, and the side wall 2111 surrounds the electrode assembly 22. The first wall 213 includes a body portion 2132 and an abutment portion 2131. The body portion 2132 is provided with a pressure relief mechanism 25. The body portion 2132 has a first surface 21321 and a second surface 21322 disposed opposite to each other. The first surface 21321 is the surface of the first wall 213 furthest from the second wall 2112. The abutment portion 2131 is disposed around the outer edge of the body portion 2132 and protrudes from the second surface 21322. The abutment portion 2131 has an abutment surface 21311 closest to the second wall 2112, which directly or indirectly abuts against the electrode assembly 22. The abutment surface 21311 is provided with a guide groove 21312, which extends through the inner and outer peripheral surfaces of the abutment portion 2131 along its width direction. Along a first direction, the abutment portion 2131 has a third surface 21315 opposite to the bottom surface 21314 of the guide groove 21312, and the distance between the bottom surface 21314 of the guide groove 21312 and the third surface 21315 is less than the distance between the first surface 21321 and the second surface 21322.

[0114] Battery cell 20 refers to the smallest unit that makes up battery device 100.

[0115] The housing 21 includes a housing 211 and an end cap 212. The housing 211 has a receiving cavity with an opening at one end for accommodating the electrode assembly 22. The end cap 212 is connected to the housing 211 and closes the opening.

[0116] End cap 212 refers to a component that covers the opening of housing 211 to isolate the internal environment of battery cell 20 from the external environment. The shape of end cap 212 can be adapted to the shape of housing 211 to fit it. Optionally, end cap 212 can be made of a material with certain hardness and strength (such as aluminum alloy), so that end cap 212 is less prone to deformation under pressure and impact, enabling battery cell 20 to have higher structural strength and improved safety performance. The material of end cap 212 can also be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and this application embodiment does not impose any special limitations on this.

[0117] The housing 211 is a component used to cooperate with the end cap 212 to form the internal environment of the battery cell 20. This internal environment can accommodate the electrode assembly 22, electrolyte, and other components. The housing 211 and the end cap 212 can be independent components. An opening can be provided on the housing 211, and the end cap 212 can be used to close the opening to form the internal environment of the battery cell 20. Alternatively, the end cap 212 and the housing 211 can be integrated. Specifically, the end cap 212 and the housing 211 can form a common mating surface before other components are inserted into the housing. When it is necessary to encapsulate the interior of the housing 211, the end cap 212 closes the housing 211. The housing 211 can have various shapes and sizes, such as cuboid or hexagonal prism. Specifically, the shape of the housing 211 can be determined according to the specific shape and size of the electrode assembly 22. The material of the housing 211 can include, but is not limited to, copper, iron, aluminum, stainless steel, aluminum alloy, and plastic.

[0118] In some embodiments, the housing 211 may have an opening at only one end, with one end cap 212 correspondingly provided. In other embodiments, the housing 211 may have openings at both ends, with two end caps 212 correspondingly provided, the two end caps 212 respectively closing the two opposite openings of the housing 211. Figure 3 In the embodiment shown, the housing 211 has an opening at only one end, and an end cap 212 is provided accordingly.

[0119] Electrode terminals 24 may also be provided on the end cap 212 or the housing 211. These terminals are used for electrical connection to the tabs 222 of the electrode assembly 22 to input or output electrical energy from the battery cell 20. The electrode terminals 24 and tabs 222 can be directly connected, for example, by direct welding. Alternatively, they can be indirectly connected, for example, through a current collector 23. The current collector 23 can be a metallic conductor, such as copper, iron, aluminum, steel, or aluminum alloy.

[0120] As an example, in Figure 3 In the illustrated embodiment, the battery cell 20 is a cylindrical battery cell, the housing 211 has an opening at only one end, and there is one end cap 212 that closes the opening of the housing 211. Electrode terminals 24 are provided on the walls of the housing 211 and the end cap 212 opposite to each other. The electrode assembly 22 has tabs 222 at both opposite ends. One tab 222 at one end of the electrode assembly 22 is the positive tab, and the other tab 222 at the other end is the negative tab. The electrode terminal 24 is electrically connected to the positive tab through a current collector 23, and the end cap 212 is electrically connected to the negative tab through another current collector 23.

[0121] Electrode assembly 22 is the component in the battery cell 20 where electrochemical reactions occur. The housing 211 may contain one or more electrode assemblies 22. The electrode assembly 22 is mainly formed by winding or stacking positive and negative electrode sheets, and typically a separator is provided between the positive and negative electrode sheets. The portions of the positive and negative electrode sheets containing active material constitute the main body 221 of the electrode assembly 22, while the portions of the positive and negative electrode sheets without active material each constitute tabs 222. The positive and negative tabs may be located together at one end of the main body or at opposite ends of the main body 221. During the charging and discharging process of the battery cell 20, the positive and negative active materials react with the electrolyte.

[0122] In embodiments where the housing 211 has an opening at only one end, the end cap 212 can serve as the first wall 213, and the wall portion of the housing 211 opposite to the end cap 212 can serve as the second wall 2112. The side wall 2111 and the second wall 2112 are integrally formed to constitute the housing 211. Alternatively, the wall portion of the housing 211 opposite to the end cap 212 can serve as the first wall 213, the end cap 212 as the second wall 2112, and the side wall 2111 and the first wall 213 can be integrally formed to constitute the housing 211. In embodiments where both ends of the housing 211 have openings, one end cap 212 serves as the first wall 213, the other end cap 212 serves as the second wall 2112, and the side wall 2111 constitutes the housing 211.

[0123] Please refer to Figure 3 The first direction is the X direction shown in the figure.

[0124] The sidewall 2111 can be cylindrical, making the battery cell 20 a cylindrical battery cell; the sidewall 2111 can also be cuboid, making the battery cell 20 a prismatic battery cell or a blade battery cell. The sidewall 2111 and the first wall 213 can be integrally formed, constituting the housing 211. An opening in the housing 211 is formed at the end of the sidewall 2111 away from the first wall 213 along a first direction, and the second wall 2112 closes the opening, in which case the second wall 2112 serves as an end cap 212. Alternatively, the sidewall 2111 and the first wall 213 can be separate, with the first wall 213 serving as the end cap 212, and an opening in the housing 211 is formed at the end of the sidewall 2111 near the first wall 213 along a first direction. In embodiments where the sidewall 2111 and the first wall 213 are separate, the first wall 213 and the sidewall 2111 can be connected by welding, bonding, or roll sealing.

[0125] The main body 2132 and the abutment part 2131 can be integrally formed or can be separately provided and connected. The abutment part 2131 can be a ring structure surrounding the outer edge of the main body 2132. The ring structure can be a circular ring structure, a rectangular ring structure, etc.

[0126] The pressure relief mechanism 25 is a component used to actuate when the internal pressure or temperature of the battery cell 20 reaches a threshold, thereby releasing the internal pressure of the battery cell 20. The pressure relief mechanism 25 may be a component mounted on the body portion 2132, in which case the pressure relief mechanism 25 and the body portion 2132 are separately provided but connected. For example, the pressure relief mechanism 25 may be an explosion-proof plate mounted on the body portion 2132. Alternatively, the pressure relief mechanism 25 may be part of the body portion 2132, in which case the pressure relief mechanism 25 and the body portion 2132 are integrally formed.

[0127] The pressure relief mechanism 25 includes a weak portion 251, which serves to relieve pressure. When the internal pressure or temperature of the battery cell 20 reaches a threshold, the pressure relief mechanism 25 can break along the weak portion 251 to release the internal pressure of the battery cell 20. In some embodiments, the strength of the pressure relief mechanism 25 at the weak portion 251 may be lower than the strength at other locations, so that when the internal pressure or temperature of the battery cell 20 reaches the threshold, the weak portion 251 can break under the internal pressure to release the internal pressure of the battery cell 20. In other embodiments, the melting point of the pressure relief mechanism 25 at the weak portion 251 may be lower than the melting point at other locations. Thus, when the internal pressure or temperature of the battery cell 20 reaches the threshold, the weak portion 251 can break under high temperature to release the internal pressure of the battery cell 20.

[0128] In some embodiments, the body portion 2132 is provided with a pressure relief groove 252, and the remaining portion of the body portion 2132 at the location where the pressure relief groove 252 is provided is the aforementioned weak portion 251. The pressure relief groove 252 can be formed by various methods, such as stamping or cold heading. By providing the pressure relief groove 252 on the body portion 2132, an integrated pressure relief mechanism is formed, which simplifies the forming method of the pressure relief mechanism 25 and increases its reliability.

[0129] The body portion 2132 has a first surface 21321 and a second surface 21322, which are disposed opposite to each other along a first direction. The first surface 21321 is the surface of the first wall 213 furthest from the second wall 2112, i.e., the first surface 21321 is the outer surface of the first wall 213. The abutment portion 2131 protrudes from the second surface 21322 in a direction from the first surface 21321 toward the second surface 21322. In other words, the abutment portion 2131 protrudes from the body portion 2132 in a direction close to the electrode assembly 22.

[0130] The main body 2132 and the abutment part 2131 together define a flow guiding space, which corresponds to the pressure relief mechanism 25. After the pressure relief mechanism 25 is actuated, the discharge located in the flow guiding space can be discharged to the outside of the battery cell 20 through the pressure relief mechanism 25. Along the first direction, the flow guiding space has an opening at the end of the abutment part 2131 near the electrode assembly 22. After the abutment part 2131 directly or indirectly abuts against the electrode assembly 22, the opening is covered. It can be understood that if the abutment part 2131 directly abuts against the electrode assembly 22, the opening of the flow guiding space is covered by the electrode assembly 22; if the abutment part 2131 indirectly abuts against the electrode assembly 22 through an intermediate member, the opening of the flow guiding space is covered by the intermediate member.

[0131] The emissions from the battery cell 20 mentioned in this application embodiment include, but are not limited to: electrolyte, dissolved or split positive and negative electrode plates, fragments of the separator, high-temperature and high-pressure gases generated by the reaction, flames, etc.

[0132] The abutment surface 21311 is the surface of the abutment portion 2131 closest to the second wall 2112 along the first direction. The abutment surface 21311 can directly or indirectly abut against the electrode assembly 22. After the abutment surface 21311 directly or indirectly abuts against the electrode assembly 22, the abutment portion 2131 and the electrode assembly 22 can be electrically connected or insulated connected. If the abutment surface 21311 directly abuts against the electrode assembly 22, the abutment portion 2131 and the electrode assembly 22 are in direct contact. For example, the abutment portion 2131 directly abuts against the tab 222 at the end of the electrode assembly 22 to achieve an electrical connection between the first wall 213 and the electrode assembly 22. If the abutment surface 21311 indirectly abuts against the electrode assembly 22, an intermediate member is provided between the abutment portion 2131 and the electrode assembly 22. This intermediate member can be an insulating member or a conductive member. Taking the current collector 23 as an example, the abutment surface 21311 can indirectly abut against the tab 222 at the end of the electrode assembly 22 through the current collector 23, so as to realize the electrical connection between the first wall 213 and the electrode assembly 22.

[0133] Please refer to Figure 3 , Figure 4 , Figure 5 , Figure 6 and Figure 7In the embodiment shown in the figure, the battery cell 20 may further include a current collector 23. The current collector 23 is disposed along a first direction between the first wall 213 and the electrode assembly 22. The current collector 23 electrically connects the electrode assembly 22 and the first wall 213. The abutment portion 2131 directly abuts against the current collector 23, and the current collector 23 directly abuts against the electrode assembly 22. The current collector 23 is a conductive component that enables the electrical connection between the electrode assembly 22 and the first wall 213. The current collector 23 is located inside the housing 21 and between the first wall 213 and the electrode assembly 22. The current collector 23 can be welded to the tab 222 at the end of the electrode assembly 22, and the current collector 23 can also be welded to the abutment portion 2131. In this embodiment, the abutment portion 2131 indirectly abuts against the electrode assembly 22 through the current collector 23. The current collector 23 enables the electrical connection between the electrode assembly 22 and the first wall 213, reducing the difficulty of the electrical connection between the electrode assembly 22 and the first wall 213.

[0134] The flow guide groove 21312 is a recess provided on the abutment surface 21311. The flow guide groove 21312 is recessed from the abutment surface 21311 in a direction away from the electrode assembly 22, and the opening of the flow guide groove 21312 is located on the abutment surface 21311. The flow guide groove 21312 penetrates through the inner and outer peripheral surfaces of the abutment portion 2131 along the width direction of the abutment portion 2131, so that the outer space of the abutment portion 2131 communicates with the inner space of the abutment portion 2131. Please refer to... Figure 3 , Figure 4 , Figure 5 , Figure 6 and Figure 7 In the embodiment shown in the figure, the battery cell 20 is a cylindrical battery cell, and the guide groove 21312 penetrates the inner peripheral surface and the outer peripheral surface of the abutment portion 2131 along the radial direction of the cylindrical battery cell 20.

[0135] The guide groove 21312 on the abutment portion 2131 can be one or more. If there are multiple guide grooves 21312, the multiple guide grooves 21312 can be evenly distributed along the circumference of the abutment portion 2131, or they can be non-uniformly distributed along the circumference of the abutment portion 2131. The circumference of the abutment portion 2131 can be the circumference of a circle surrounding a centerline extending along the first direction.

[0136] In other words, the abutment portion 2131 includes multiple protrusions that directly or indirectly abut against the electrode assembly 22. Along the circumference of the abutment portion 2131, a guide groove 21312 is formed between two adjacent protrusions. The abutment portion 2131 can have two, three, four, five, or more protrusions. The number of guide grooves 21312 is equal to the number of protrusions, and they are alternately arranged along the circumference of the abutment portion 2131. As an example, the multiple protrusions in the abutment portion 2131 are evenly distributed along the circumference of the abutment portion 2131, meaning that the angle between any two adjacent protrusions along the circumference of the abutment portion 2131 is equal. Taking four protrusions in the abutment portion 2131 as an example, the distance between any two adjacent protrusions along the circumference of the abutment portion 2131 is 90°. The protrusion is located inside the side wall 2111, and the protrusion can contact the inner surface of the side wall 2111, and the two can also have a gap.

[0137] In an embodiment where the abutment surface 21311 directly abuts against the electrode assembly 22, the abutment surface 21311 may directly contact the tab 222 at the end of the electrode assembly 22, and the tab 222 may cover the groove formed by the guide groove 21312 on the abutment surface 21311; in an embodiment where the abutment surface 21311 and the electrode assembly 22 indirectly abut against the electrode assembly 22 through an intermediate component, the abutment surface 21311 may directly contact the intermediate component, and the intermediate component may cover the groove formed by the guide groove 21312 on the abutment surface 21311.

[0138] The abutment portion 2131 has a third surface 21315, which is disposed opposite to the bottom surface 21314 of the guide channel 21312 along a first direction. The bottom surface 21314 of the guide channel 21312 is the surface of the bottom wall 21313 of the guide channel 21312 facing the electrode assembly 22, and the third surface 21315 is the surface of the bottom wall 21313 of the guide channel 21312 facing away from the electrode assembly 22.

[0139] Please refer to Figure 3 , Figure 4 , Figure 5 , Figure 6 and Figure 7In the figure, H1 represents the distance between the bottom surface 21314 of the guide channel 21312 and the third surface 21315 along the first direction, and H2 represents the distance between the bottom surface 21314 of the guide channel 21312 and the first surface 21321 and the second surface 21322 along the first direction, satisfying that H1 < H2. Thus, during manufacturing, the bottom surface 21314 of the guide channel 21312 can be thinned, for example, by forming methods such as stamping or cold heading to thin the bottom wall 21313 of the guide channel 21312. In this way, while keeping the depth of the guide channel 21312 constant, the height of the abutment 2131 protruding from the second surface 21322 can be reduced, allowing the dimension of the first wall 213 along the first direction to be reduced.

[0140] The first wall 213 includes abutment portion 2131, the abutment surface 21311 of which directly or indirectly abuts against the electrode assembly 22. The abutment portion 2131 can restrict the electrode assembly 22, reducing the risk of the electrode assembly 22 moving along the first direction within the housing 21. Since the abutment portion 2131 is provided with a guide groove 21312 penetrating the inner and outer peripheral surfaces of the abutment portion 2131, when the battery cell 20 experiences thermal runaway, the discharge outside the abutment portion 2131 can flow to the pressure relief mechanism 25 through the guide groove 21312. This facilitates the rapid actuation of the pressure relief mechanism 25, shortening the time from thermal runaway of the battery cell 20 to the start of pressure relief by the pressure relief mechanism 25, reducing the risk of battery cell 20 explosion and fire, and effectively improving the reliability of the battery cell 20. By making the distance between the bottom surface 21314 of the guide channel 21312 and the third surface 21315 smaller than the distance between the first surface 21321 and the second surface 21322, that is, by thinning the portion of the abutment 2131 located between the bottom surface 21314 and the third surface 21315 of the guide channel 21312, the height of the abutment 2131 protruding from the second surface 21322 can be reduced while keeping the depth of the guide channel 21312 unchanged. This allows the size of the first wall 213 along the first direction to be reduced, thereby providing more space for the electrode assembly 22 and improving the energy density of the battery cell 20.

[0141] In addition, by controlling the thinning of the portion of the abutment 2131 located between the bottom surface 21314 and the third surface 21315 of the guide channel 21312, the height of the abutment 2131 protruding from the second surface 21322 can be reduced, and the depth of the guide channel 21312 can also be increased. This makes it easier for the discharge outside the abutment 2131 to flow through the guide channel 21312 to the pressure relief mechanism 25, further shortening the time from thermal runaway of the battery cell 20 to the start of pressure relief of the battery cell 20 through the pressure relief mechanism 25. This is beneficial to improving the timeliness of pressure relief of the battery cell 20 and improving the reliability of the battery cell 20.

[0142] Please refer to Figure 3 , Figure 4 , Figure 5 , Figure 6 and Figure 7 In some embodiments, along the first direction, the distance between the bottom surface 21314 of the guide channel 21312 and the third surface 21315 is H1, and the distance between the first surface 21321 and the second surface 21322 is H2, satisfying: 0.5≤H1 / H2<1.

[0143] H1 represents the distance between the bottom surface 21314 of the guide channel 21312 and the third surface 21315 along the first direction, which is also the thickness of the bottom wall 21313 of the guide channel 21312. During measurement, multiple measurements can be taken and the average value can be used as H1.

[0144] H2 represents the distance between the first surface 21321 and the second surface 21322 along the first direction. During measurement, multiple measurements can be taken and the average value can be used as H2.

[0145] H1 / H2 represents the ratio of the distance between the bottom surface 21314 and the third surface 21315 of the flow guide channel 21312 along the first direction to the distance between the first surface 21321 and the second surface 21322 along the first direction. The ratio of the distance between the bottom surface 21314 and the third surface 21315 of the flow guide channel 21312 along the first direction to the distance between the first surface 21321 and the second surface 21322 along the first direction is greater than or equal to 0.5 and less than 1.

[0146] H1 / H2 can be 0.5, 0.55, 0.6, 0.65, 0.7, 0.75, 0.8, 0.85, 0.9, 0.95, etc.

[0147] When H1 / H2 < 1, along the first direction, the distance between the bottom surface 21314 of the guide channel 21312 and the third surface 21315 is less than the distance between the first surface 21321 and the second surface 21322. That is, the portion of the abutment 2131 located between the bottom surface 21314 and the third surface 21315 of the guide channel 21312 is thinned. In this way, while the depth of the guide channel 21312 remains unchanged, the height of the abutment 2131 protruding from the second surface 21322 can be reduced, so that the size of the first wall 213 along the first direction can be reduced, thereby providing more space to place the electrode assembly 22, which is beneficial to improving the energy density of the battery cell 20. When H1 / H2 ≥ 0.5, the distance between the bottom surface 21314 and the third surface 21315 of the guide channel 21312 is not too small, ensuring that the portion of the abutment 2131 located between the bottom surface 21314 and the third surface 21315 of the guide channel 21312 is not too thin. This ensures that the portion of the abutment 2131 located between the bottom surface 21314 and the third surface 21315 of the guide channel 21312 has sufficient strength, reducing the risk of deformation or breakage of this portion and thus improving the reliability of the battery cell 20. Therefore, when 0.5 ≤ H1 / H2 < 1, both the reliability and energy density of the battery cell 20 can be balanced.

[0148] Optionally, 0.6 ≤ H1 / H2 ≤ 0.8.

[0149] H1 / H2 can take values ​​of 0.6, 0.61, 0.62, 0.63, 0.64, 0.65, 0.66, 0.67, 0.68, 0.69, 0.7, 0.71, 0.72, 0.73, 0.74, 0.75, 0.76, 0.77, 0.78, 0.79, 0.8, etc.

[0150] When H1 / H2≤0.8, along the first direction, the distance between the bottom surface 21314 of the guide channel 21312 and the third surface 21315 is small, that is, the thinning degree of the portion of the abutment 2131 located between the bottom surface 21314 and the third surface 21315 of the guide channel 21312 is large. With the depth of the guide channel 21312 remaining unchanged, the height of the abutment 2131 protruding from the second surface 21322 can be further reduced, so that the size of the first wall 213 along the first direction can be further reduced, thereby providing more space to place the electrode assembly 22, which is more conducive to improving the energy density of the battery cell 20. When H1 / H2 ≥ 0.6, the distance between the bottom surface 21314 and the third surface 21315 of the guide channel 21312 is not too small, ensuring that the portion of the abutment 2131 located between the bottom surface 21314 and the third surface 21315 of the guide channel 21312 is not too thin. This provides sufficient strength to reduce the risk of deformation or breakage of this portion, thus improving the reliability of the battery cell 20. Therefore, when 0.6 ≤ H1 / H2 ≤ 0.8, a better balance between the reliability and energy density of the battery cell 20 can be achieved.

[0151] Please refer to Figure 3 , Figure 4 , Figure 5 , Figure 6 and Figure 7 In some embodiments, along the first direction, the distance between the bottom surface 21314 of the guide channel 21312 and the third surface 21315 is H1, which satisfies: 0.18mm≤H1≤1.5mm.

[0152] H1 can be 0.18mm, 0.2mm, 0.4mm, 0.6mm, 0.8mm, 1mm, 1.2mm, 1.4mm, 1.5mm, etc.

[0153] When H1≤1.5mm, the distance between the bottom surface 21314 of the guide channel 21312 and the third surface 21315 is small along the first direction, which is beneficial to reduce the size of the first wall 213 along the first direction, thereby allowing more space to be placed for the electrode assembly 22, which is beneficial to improve the energy density of the battery cell 20. When H1 ≥ 0.18 mm, the distance between the bottom surface 21314 and the third surface 21315 of the guide channel 21312 is not too small, ensuring that the portion of the abutment 2131 located between the bottom surface 21314 and the third surface 21315 of the guide channel 21312 is not too thin. This ensures that the portion of the abutment 2131 located between the bottom surface 21314 and the third surface 21315 of the guide channel 21312 has sufficient strength, reducing the risk of deformation or breakage of this portion and thus improving the reliability of the battery cell 20. Therefore, when 0.18 mm ≤ H1 ≤ 1.5 mm, both the reliability and energy density of the battery cell 20 can be balanced.

[0154] Optionally, 0.3mm ≤ H1 ≤ 0.5mm.

[0155] H1 can be 0.3mm, 0.32mm, 0.34mm, 0.36mm, 0.38mm, 0.4mm, 0.42mm, 0.44mm, 0.46mm, 0.48mm, 0.5mm, etc.

[0156] When H1≤0.5mm, the distance between the bottom surface 21314 of the guide channel 21312 and the third surface 21315 is smaller along the first direction, which is more conducive to reducing the size of the first wall 213 along the first direction, thereby allowing more space to be placed for the electrode assembly 22, which is beneficial to improving the energy density of the battery cell 20. When H1 ≥ 0.3 mm, the distance between the bottom surface 21314 and the third surface 21315 of the guide channel 21312 is not too small, ensuring that the portion of the abutment 2131 located between the bottom surface 21314 and the third surface 21315 of the guide channel 21312 is not too thin. This ensures that the portion of the abutment 2131 located between the bottom surface 21314 and the third surface 21315 of the guide channel 21312 has sufficient strength, reducing the risk of deformation or breakage of this portion and thus improving the reliability of the battery cell 20. Therefore, when 0.3 mm ≤ H1 ≤ 0.5 mm, both the reliability and energy density of the battery cell 20 can be balanced.

[0157] Please refer to Figure 3 , Figure 4 , Figure 5 , Figure 6 and Figure 7 In some embodiments, along the first direction, the distance between the first surface 21321 and the second surface 21322 is H2, which satisfies: 0.3mm≤H2≤2.5mm.

[0158] H2 can be 0.3mm, 0.5mm, 0.8mm, 1mm, 1.2mm, 1.5mm, 1.8mm, 2mm, 2.2mm, 2.5mm, etc.

[0159] When H2 ≥ 0.3 mm, the distance between the first surface 21321 and the second surface 21322 along the first direction is relatively large. This results in sufficient thickness for the portion of the body 2132 located between the first surface 21321 and the second surface 21322, and sufficient strength for this portion. This helps reduce the risk of deformation and breakage of the body 2132, thus improving the reliability of the battery cell 20. When H2 ≤ 2.5 mm, the distance between the first surface 21321 and the second surface 21322 along the first direction is not too large. On the one hand, this helps reduce the size of the first wall 213 along the first direction, allowing more space to be placed for the electrode assembly 22, which helps improve the energy density of the battery cell 20. On the other hand, it helps reduce the material used in the first wall 213, thereby reducing the manufacturing cost of the battery cell 20. Therefore, when 0.3 mm ≤ H2 ≤ 2.5 mm, both the reliability and energy density of the battery cell 20 can be balanced.

[0160] Optionally, 0.45mm≤H2≤0.8mm.

[0161] H2 can be 0.45mm, 0.5mm, 0.55mm, 0.6mm, 0.65mm, 0.7mm, 1.8mm, 2mm, 2.2mm, 2.5mm, etc.

[0162] When H2 ≥ 0.45 mm, the distance between the first surface 21321 and the second surface 21322 along the first direction is larger, resulting in a greater thickness of the portion of the body 2132 located between the first surface 21321 and the second surface 21322. This portion of the body 2132 has better strength, which is more conducive to reducing the risk of deformation and breakage of the body 2132 and improving the reliability of the battery cell 20. When H2 ≤ 0.8 mm, the distance between the first surface 21321 and the second surface 21322 along the first direction is not too large. On the one hand, this helps to reduce the size of the first wall 213 along the first direction, thereby providing more space for the electrode assembly 22 and improving the energy density of the battery cell 20. On the other hand, it helps to reduce the material used in the first wall 213, thereby reducing the manufacturing cost of the battery cell 20. Therefore, when 0.45 mm ≤ H2 ≤ 0.8 mm, both the reliability and energy density of the battery cell 20 can be balanced.

[0163] Please refer to Figure 3 , Figure 4 , Figure 5 , Figure 6 and Figure 7 In some embodiments, along the first direction, the distance between the abutment surface 21311 and the bottom surface 21314 of the guide channel 21312 is H3, which satisfies: 0.2mm≤H3≤1.8mm.

[0164] H3 represents the distance along the first direction between the contact surface 21311 and the bottom surface 21314 of the guide channel 21312, which is also the depth of the guide channel 21312. During measurement, multiple measurements can be taken and the average value can be used as H3.

[0165] H3 can be 0.2mm, 0.3mm, 0.4mm, 0.6mm, 0.8mm, 1mm, 1.2mm, 1.4mm, 1.6mm, 1.7mm, 1.8mm, etc.

[0166] When H3 ≥ 0.2 mm, the distance between the contact surface 21311 and the bottom surface 21314 of the guide channel 21312 along the first direction is relatively large, and the depth of the guide channel 21312 is relatively large. This makes it easier for the discharge outside the contact part 2131 to flow through the guide channel 21312 to the pressure relief mechanism 25, shortening the time from the thermal runaway of the battery cell 20 to the start of pressure relief by the pressure relief mechanism 25, which is beneficial to improving the timeliness of pressure relief of the battery cell 20 and improving the reliability of the battery cell 20. When H3 ≤ 1.8 mm, the distance between the contact surface 21311 and the bottom surface 21314 of the guide channel 21312 along the first direction is not too large, and the depth of the guide channel 21312 is not too deep. This is beneficial to reducing the size of the first wall 213 along the first direction and improving the energy density of the battery cell 20. Therefore, when 0.2 mm ≤ H3 ≤ 1.8 mm, the reliability and energy density of the battery cell 20 can be balanced.

[0167] Optionally, 0.4mm ≤ H3 ≤ 1.6mm.

[0168] H3 can be 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1mm, 1.1mm, 1.2mm, 1.3mm, 1.4mm, 1.5mm, 1.6mm, etc.

[0169] When H3 ≥ 0.4 mm, the distance between the contact surface 21311 and the bottom surface 21314 of the guide channel 21312 along the first direction is larger, and the depth of the guide channel 21312 is greater. This makes it easier for the discharge outside the contact part 2131 to flow through the guide channel 21312 to the pressure relief mechanism 25, shortening the time from the thermal runaway of the battery cell 20 to the start of pressure relief by the pressure relief mechanism 25, which is beneficial to improving the timeliness of pressure relief of the battery cell 20 and improving the reliability of the battery cell 20. When H3 ≤ 1.6 mm, the distance between the contact surface 21311 and the bottom surface 21314 of the guide channel 21312 along the first direction is not too large, and the depth of the guide channel 21312 is not too deep. This is beneficial to reducing the size of the first wall 213 along the first direction and improving the energy density of the battery cell 20. Therefore, when 0.4mm≤H3≤1.6mm, the reliability and energy density of the battery cell 20 can be better balanced.

[0170] Please refer to Figure 3 , Figure 4 , Figure 5 , Figure 6 and Figure 7 In some embodiments, along the first direction, the third surface 21315 is closer to the second wall 2112 than the second surface 21322.

[0171] "Along the first direction, the third surface 21315 is closer to the second wall 2112 than the second surface 21322", that is, the distance between the third surface 21315 and the second wall 2112 along the first direction is less than the distance between the second surface 21322 and the second wall 2112 along the first direction.

[0172] By making the third surface 21315 closer to the second wall 2112 than the second surface 21322, it is beneficial to reduce the risk of external forces acting on the part of the abutment 2131 located between the bottom surface 21314 of the guide channel 21312 and the third surface 21315. This reduces the risk of deformation and breakage of the part of the abutment 2131 located between the bottom surface 21314 of the guide channel 21312 and the third surface 21315, which is beneficial to improving the reliability of the battery cell 20.

[0173] In some embodiments, the hardness of the portion of the abutment 2131 located between the bottom surface 21314 and the third surface 21315 of the guide channel 21312 is greater than the hardness of the portion of the body portion 2132 located between the first surface 21321 and the second surface 21322.

[0174] The hardness of the portion of the abutment 2131 located between the bottom surface 21314 and the third surface 21315 of the guide channel 21312 is the first hardness, that is, the hardness of the bottom wall 21313 of the guide channel 21312 is the first hardness. The hardness of the portion of the body 2132 located between the first surface 21321 and the second surface 21322 is the second hardness. The first hardness is greater than the second hardness.

[0175] The hardness of the portion of the abutment 2131 located between the bottom surface 21314 and the third surface 21315 of the guide groove 21312, and the hardness of the portion of the body 2132 located between the first surface 21321 and the second surface 21322, can be Vickers hardness. Vickers hardness refers to the Vickers hardness value of a metal obtained by pressing a diamond pyramid indenter with a 136-degree angle between its opposite faces into the surface of a test sample under a specified load, holding it for a certain time, removing the load, measuring the diagonal length of the indentation, calculating the surface area of ​​the indentation, and finally determining the average pressure on the indentation surface area. This value is represented by the symbol HV. In actual measurements, calculation is not required; instead, the hardness value is obtained directly from a table based on the measured diagonal length of the indentation.

[0176] The hardness of the portion of the abutment 2131 located between the bottom surface 21314 and the third surface 21315 of the guide channel 21312 is greater than the hardness of the portion of the body 2132 located between the first surface 21321 and the second surface 21322. During manufacturing, the bottom wall 21313 of the guide channel 21312 can be thinned by forming methods such as stamping and cold heading, which is simple and convenient to manufacture and has a low cost.

[0177] Please refer to Figure 3 , Figure 4 , Figure 5 , Figure 6 and Figure 7 In some embodiments, the abutment portion 2131 includes a first portion 21316 and a first transition portion 2133. The first portion 21316 is the bottom wall 21313 of the guide channel 21312. The surface of the first portion 21316 facing away from the second wall 2112 is the third surface 21315. The first transition portion 2133 connects the first portion 21316 and the body portion 2132. The thickness of the first transition portion 2133 is greater than the thickness of the first portion 21316.

[0178] The first part 21316 is the bottom wall 21313 of the guide channel 21312, the surface of the first part 21316 facing the second wall 2112 is the bottom surface 21314 of the guide channel 21312, and the surface of the first part 21316 away from the second wall 2112 is the third surface 21315.

[0179] The first transition section 2133 is the part that connects the first part 21316 and the main body part 2132 to the abutment part 2131.

[0180] It should be noted that the thickness of the first transition portion 2133 refers to the thickness measured along the thickness direction of the first transition portion 2133, and not necessarily along the first direction.

[0181] The thickness of the first part 21316 is also the distance between the bottom surface 21314 of the guide channel 21312 and the third surface 21315 along the first direction.

[0182] During manufacturing, the bottom wall 21313 of the guide channel 21312 can be thinned by forming methods such as stamping and cold heading. During the processing, the bottom wall 21313 of the guide channel 21312 will squeeze material towards the first transition portion 2133, thereby increasing the thickness of the first transition portion 2133, making the thickness of the first transition portion 2133 greater than the thickness of the first portion 21316.

[0183] Please refer to Figure 3 , Figure 4 , Figure 5 , Figure 6 and Figure 7 In some embodiments, the first wall 213 further includes an edge portion 2135, which surrounds the outer edge of the abutment portion 2131. Along the first direction, the abutment surface 21311 is closer to the second wall 2112 than the edge portion 2135, and the edge portion 2135 is located on the side of the side wall 2111 opposite to the second wall 2112 and is connected to the side wall 2111.

[0184] The edge portion 2135 is an annular structure surrounding the outer edge of the abutment portion 2131. The outer edge of the edge portion 2135 is the outer edge of the first wall 213.

[0185] As an example, the sidewall 2111 is part of the outer shell 21, the outer shell 21 has an opening at only one end along the first direction, the edge portion 2135 abuts against the end of the outer shell 21 with the opening along the direction from the first wall 213 to the second wall 2112, and the edge portion 2135 is welded to the sidewall 2111.

[0186] The first wall 213 also includes an edge portion 2135, which abuts against the side wall 2111 to limit the first wall 213 and restrict the first wall 213 from moving in the direction close to the electrode assembly 22.

[0187] Please refer to Figure 3 , Figure 4 , Figure 5 , Figure 6 and Figure 7 In some embodiments, the abutment portion 2131 includes a first portion 21316 and a second transition portion 2134. The first portion 21316 is the bottom wall 21313 of the guide channel 21312, and the surface of the first portion 21316 facing away from the second wall 2112 is a third surface 21315. The second transition portion 2134 connects the first portion 21316 and the edge portion 2135, and the thickness of the second transition portion 2134 is greater than the thickness of the first portion 21316.

[0188] The second transition section 2134 is the part that connects the first part 21316 and the edge part 2135 to the abutment part 2131.

[0189] It should be noted that the thickness of the second transition portion 2134 refers to the thickness measured along the thickness direction of the second transition portion 2134, and not necessarily along the first direction.

[0190] During manufacturing, the bottom wall 21313 of the guide channel 21312 can be thinned by forming methods such as stamping and cold heading. During the processing, the bottom wall 21313 of the guide channel 21312 will squeeze material towards the second transition portion 2134, thereby increasing the thickness of the second transition portion 2134, making the thickness of the second transition portion 2134 greater than the thickness of the first portion 21316.

[0191] Please refer to Figure 3 , Figure 4 , Figure 5 , Figure 6 and Figure 7 In some embodiments, a first flow channel 2113 is formed between the sidewall 2111 and the electrode assembly 22, and the first flow channel 2113 is connected to the guide groove 21312.

[0192] The first flow channel 2113 can be the gap formed between the outer peripheral surface of the main body 221 of the electrode assembly 22 and the outer peripheral surface of the tab 222 of the electrode assembly 22 and the inner peripheral surface 141 of the sidewall 2111. Alternatively, if the outer periphery of the main body 221 is covered with an insulating film, the first flow channel 2113 can be the gap formed between the outer peripheral surface of the insulating film and the outer peripheral surface of the tab 222 and the inner peripheral surface 141 of the sidewall 2111. The inner peripheral surface 141 of the sidewall 2111 is the surface of the sidewall 2111 facing the electrode assembly 22, and the inner peripheral surface 141 can extend circumferentially around the opening of the outer casing 21. It can be understood that if the sidewall 2111 is cylindrical, the inner peripheral surface 141 of the sidewall 2111 is cylindrical; if the sidewall 2111 is cuboid, the inner peripheral surface 141 of the sidewall 2111 is cuboid.

[0193] By connecting the first flow channel 2113 and the guide groove 21312, when the battery cell 20 experiences thermal runaway, the discharge from the first flow channel 2113 can flow to the pressure relief mechanism 25 through the guide groove 21312. This facilitates the rapid activation of the pressure relief mechanism 25, shortens the time from thermal runaway of the battery cell 20 to the start of pressure relief through the pressure relief mechanism 25, reduces the risk of explosion and fire of the battery cell 20, and effectively improves the reliability of the battery cell 20.

[0194] Please refer to Figure 3 , Figure 4 , Figure 5 , Figure 6 and Figure 7In some embodiments, the body portion 2132 includes a second portion 2136 and a third portion 2137, with the second portion 2136 connecting the third portion 2137 and the abutment portion 2131. Along a first direction, the third portion 2137 protrudes from the second portion 2136 in a direction close to the second wall 2112, and a pressure relief mechanism 25 is disposed on the third portion 2137. The surface of the second portion 2136 facing away from the second wall 2112 is the first surface 21321.

[0195] The first surface 21321 is provided with a first groove 21361, which is recessed from the first surface 21321 toward the second wall 2112, so as to form a third portion 2137 that at least partially protrudes from the second surface 21322 on the side of the second portion 2136 facing the second wall 2112. In other words, the bottom wall of the first groove 21361 is the third portion 2137.

[0196] The weak point 251 is located in the third part 2137, and the aforementioned pressure relief groove 252 is provided in the third part 2137. Please refer to... Figure 7 In the embodiment shown in the figure, the pressure relief groove 252 is provided on the surface of the third part 2137 facing the second wall 2112.

[0197] Along the first direction, the surface of the second part 2136 facing away from the second wall 2112 is the first surface, and the surface of the second part 2136 facing the second wall 2112 is the second surface.

[0198] The third part 2137 protrudes from the second part 2136 along the direction close to the second wall 2112. The pressure relief mechanism 25 is disposed in the third part 2137, which increases the distance between the pressure relief mechanism 25 and the external component when the first surface 21321 contacts the external component, reduces the influence of the external component on the pressure relief mechanism 25, and reduces the risk of the pressure relief mechanism 25 being prematurely actuated by the impact force of the external component.

[0199] Please refer to Figure 3 , Figure 4 , Figure 5 , Figure 6 and Figure 7 In some embodiments, the outer casing 21 includes a housing 211 and an end cap 212. One end of the housing 211 has an opening, and the end cap 212 closes the opening. The end cap 212 is a first wall 213. Along a first direction, the wall portion of the housing 211 opposite to the end cap 212 is a second wall.

[0200] The housing 21 may include a housing 211 and an end cap 212. The interior of the housing 211 forms an accommodating space with an opening for accommodating the electrode assembly 22. The end cap 212 closes the opening and is a first wall 213. The bottom wall of the housing 211, which is opposite to the end cap 212, is a second wall 2112.

[0201] It should be noted that the structure of the battery cell 20 can be varied. In some embodiments, the outer casing 21 may include a housing 211 and two end caps 212. The housing 211 has an internal accommodating space for accommodating the electrode assembly 22. Both ends of the housing 211 have openings that communicate with the accommodating space. The two end caps 212 close the two openings respectively. One end cap 212 is a first wall 213, and the other end cap 212 is a second wall 2112.

[0202] The housing 211 of the outer casing 21 has openings at both ends, and two end caps 212 respectively close the two openings. The first wall 213 is one of the two end caps 212, and the other end cap 212 is the second wall 2112. The battery cell 20 with this structure is easy to assemble from both ends of the housing 211, which helps to reduce the manufacturing and assembly difficulty of the battery cell 20.

[0203] When the end cap 212 is the first wall 213, the pressure relief mechanism 25 is installed on the end cap 212, which is simple and convenient to manufacture.

[0204] In other embodiments, the housing 211 includes an integrally formed sidewall 2111 and a bottom wall, meaning the housing 211 is manufactured using an integral forming process, such as stamping, casting, or extrusion molding. In other words, the sidewall 2111 and bottom wall of the housing 211 are a single, integral structure. The first wall 213 is the bottom wall of the housing 211, which is opposite to the end cap 212 in a first direction, and the second wall 2112 is the end cap.

[0205] This application embodiment also provides a battery device 100, which includes the aforementioned battery cell 20.

[0206] This application embodiment also provides an electrical device, which includes the aforementioned battery cell 20, and the battery cell 20 is used to provide electrical energy to the electrical device.

[0207] According to some embodiments of this application, please refer to Figures 3-7 .

[0208] This application provides a battery cell 20, which includes an electrode assembly 22 and a housing 21. The housing 21 accommodates the electrode assembly 22. The housing 21 includes a first wall 213, a second wall 2112, and a side wall 2111. The first wall 213 and the second wall 2112 are respectively disposed at both ends of the side wall 2111 along a first direction, and the side wall 2111 surrounds the electrode assembly 22. The first wall 213 includes a body portion 2132 and an abutment portion 2131. The body portion 2132 is provided with a pressure relief mechanism 25. The body portion 2132 has a first surface 21321 and a second surface 21322 disposed opposite to each other. The first surface 21321 is the surface of the first wall 213 furthest from the second wall 2112. The abutment portion 2131 is disposed around the outer edge of the body portion 2132 and protrudes from the second surface 21322. The abutment portion 2131 has an abutment surface 21311 closest to the second wall 2112, which directly or indirectly abuts against the electrode assembly 22. The abutment surface 21311 is provided with a guide groove 21312, which extends through the inner and outer peripheral surfaces of the abutment portion 2131 along its width direction. Along a first direction, the abutment portion 2131 has a third surface 21315 opposite to the bottom surface 21314 of the guide groove 21312, and the distance between the bottom surface 21314 of the guide groove 21312 and the third surface 21315 is less than the distance between the first surface 21321 and the second surface 21322. The first wall 213 includes abutment portion 2131, the abutment surface 21311 of which directly or indirectly abuts against the electrode assembly 22. The abutment portion 2131 can restrict the electrode assembly 22, reducing the risk of the electrode assembly 22 moving along the first direction within the housing 21. Since the abutment portion 2131 is provided with a guide groove 21312 penetrating the inner and outer peripheral surfaces of the abutment portion 2131, when the battery cell 20 experiences thermal runaway, the discharge outside the abutment portion 2131 can flow to the pressure relief mechanism 25 through the guide groove 21312. This facilitates the rapid actuation of the pressure relief mechanism 25, shortening the time from thermal runaway of the battery cell 20 to the start of pressure relief by the pressure relief mechanism 25, reducing the risk of battery cell 20 explosion and fire, and effectively improving the reliability of the battery cell 20. By making the distance between the bottom surface 21314 of the guide channel 21312 and the third surface 21315 smaller than the distance between the first surface 21321 and the second surface 21322, that is, by thinning the portion of the abutment 2131 located between the bottom surface 21314 and the third surface 21315 of the guide channel 21312, the height of the abutment 2131 protruding from the second surface 21322 can be reduced while keeping the depth of the guide channel 21312 unchanged. This allows the size of the first wall 213 along the first direction to be reduced, thereby providing more space for the electrode assembly 22 and improving the energy density of the battery cell 20.In addition, by controlling the thinning of the portion of the abutment 2131 located between the bottom surface 21314 and the third surface 21315 of the guide channel 21312, the height of the abutment 2131 protruding from the second surface 21322 can be reduced, and the depth of the guide channel 21312 can also be increased. This makes it easier for the discharge outside the abutment 2131 to flow through the guide channel 21312 to the pressure relief mechanism 25, further shortening the time from thermal runaway of the battery cell 20 to the start of pressure relief of the battery cell 20 through the pressure relief mechanism 25. This is beneficial to improving the timeliness of pressure relief of the battery cell 20 and improving the reliability of the battery cell 20.

[0209] Along the first direction, the distance between the bottom surface 21314 of the guide channel 21312 and the third surface 21315 is H1, and the distance between the first surface 21321 and the second surface 21322 is H2, satisfying: 0.6≤H1 / H2≤0.8. When H1 / H2≤0.8, along the first direction, the distance between the bottom surface 21314 of the guide channel 21312 and the third surface 21315 is smaller, that is, the thinning degree of the portion of the abutment 2131 located between the bottom surface 21314 and the third surface 21315 of the guide channel 21312 is larger. With the depth of the guide channel 21312 remaining unchanged, the height of the abutment 2131 protruding from the second surface 21322 can be reduced, so that the dimension of the first wall 213 along the first direction can be further reduced, thereby providing more space to place the electrode assembly 22, which is more conducive to improving the energy density of the battery cell 20. When H1 / H2 ≥ 0.6, the distance between the bottom surface 21314 and the third surface 21315 of the guide channel 21312 is not too small, ensuring that the portion of the abutment 2131 located between the bottom surface 21314 and the third surface 21315 of the guide channel 21312 is not too thin. This provides sufficient strength to reduce the risk of deformation or breakage of this portion, thus improving the reliability of the battery cell 20. Therefore, when 0.6 ≤ H1 / H2 ≤ 0.8, a better balance between the reliability and energy density of the battery cell 20 can be achieved.

[0210] Along the first direction, the distance between the bottom surface 21314 of the guide channel 21312 and the third surface 21315 is H1, satisfying: 0.18mm≤H1≤1.5mm. When H1≤1.5mm, the distance between the bottom surface 21314 of the guide channel 21312 and the third surface 21315 is smaller along the first direction, which helps to reduce the size of the first wall 213 along the first direction, thereby allowing more space to be placed for the electrode assembly 22, which is beneficial to improving the energy density of the battery cell 20. When H1 ≥ 0.18 mm, the distance between the bottom surface 21314 and the third surface 21315 of the guide channel 21312 is not too small, ensuring that the portion of the abutment 2131 located between the bottom surface 21314 and the third surface 21315 of the guide channel 21312 is not too thin. This ensures that the portion of the abutment 2131 located between the bottom surface 21314 and the third surface 21315 of the guide channel 21312 has sufficient strength, reducing the risk of deformation or breakage of this portion and thus improving the reliability of the battery cell 20. Therefore, when 0.18 mm ≤ H1 ≤ 1.5 mm, both the reliability and energy density of the battery cell 20 can be balanced.

[0211] The hardness of the portion of the abutment 2131 located between the bottom surface 21314 and the third surface 21315 of the guide channel 21312 is greater than the hardness of the portion of the body 2132 located between the first surface 21321 and the second surface 21322. Since the hardness of the portion of the abutment 2131 located between the bottom surface 21314 and the third surface 21315 of the guide channel 21312 is greater than the hardness of the portion of the body 2132 located between the first surface 21321 and the second surface 21322, the bottom wall 21313 of the guide channel 21312 can be thinned by forming methods such as stamping and cold heading during manufacturing. This makes manufacturing simple, convenient, and cost-effective.

[0212] The abutment portion 2131 includes a first portion 21316 and a first transition portion 2133. The first portion 21316 is the bottom wall 21313 of the guide channel 21312, and the surface of the first portion 21316 facing away from the second wall 2112 is the third surface 21315. The first transition portion 2133 connects the first portion 21316 and the main body portion 2132. The thickness of the first transition portion 2133 is greater than the thickness of the first portion 21316. During manufacturing, the bottom wall 21313 of the guide channel 21312 can be thinned by forming methods such as stamping and cold heading. During processing, the bottom wall 21313 of the guide channel 21312 will squeeze material towards the first transition portion 2133, thereby increasing the thickness of the first transition portion 2133, making the thickness of the first transition portion 2133 greater than the thickness of the first portion 21316.

[0213] The first wall 213 also includes an edge portion 2135, which surrounds the outer edge of the abutment portion 2131. Along the first direction, the abutment surface 21311 is closer to the second wall 2112 than the edge portion 2135. The edge portion 2135 is located on the side of the side wall 2111 facing away from the second wall 2112 and is connected to the side wall 2111. The abutment portion 2131 includes a first portion 21316 and a second transition portion 2134. The first portion 21316 is the bottom wall 21313 of the guide channel 21312, and the surface of the first portion 21316 facing away from the second wall 2112 is a third surface 21315. The second transition portion 2134 connects the first portion 21316 and the edge portion 2135. The thickness of the second transition portion 2134 is greater than the thickness of the first portion 21316. During manufacturing, the bottom wall 21313 of the guide channel 21312 can be thinned by forming methods such as stamping and cold heading. During the processing, the bottom wall 21313 of the guide channel 21312 will squeeze material towards the second transition portion 2134, thereby increasing the thickness of the second transition portion 2134, making the thickness of the second transition portion 2134 greater than the thickness of the first portion 21316.

[0214] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A battery cell, characterized in that, include: Electrode assembly; A housing for accommodating the electrode assembly, the housing including a first wall, a second wall and a side wall, the first wall and the second wall being respectively disposed at both ends of the side wall along a first direction, the side wall surrounding the electrode assembly; The first wall includes a body portion and an abutment portion. The body portion is provided with a pressure relief mechanism. The body portion has a first surface and a second surface disposed opposite to each other. The first surface is the surface of the first wall furthest from the second wall. The abutment portion is disposed around the outer edge of the body portion and protrudes from the second surface. The abutment portion has an abutment surface closest to the second wall. The abutment surface directly or indirectly abuts against the electrode assembly. The abutment surface is provided with a flow guide groove. The flow guide groove penetrates the inner and outer peripheral surfaces of the abutment portion along the width direction. Along the first direction, the abutment portion has a third surface disposed opposite to the bottom surface of the flow guide groove. The distance between the bottom surface of the flow guide groove and the third surface is less than the distance between the first surface and the second surface.

2. The battery cell according to claim 1, characterized in that, Along the first direction, the distance between the bottom surface of the guide channel and the third surface is H1, and the distance between the first surface and the second surface is H2, satisfying: 0.5≤H1 / H2<1, optionally, 0.6≤H1 / H2≤0.

8.

3. The battery cell according to claim 1, characterized in that, Along the first direction, the distance between the bottom surface of the guide channel and the third surface is H1, which satisfies: 0.18mm≤H1≤1.5mm, and optionally, 0.3mm≤H1≤0.5mm.

4. The battery cell according to claim 1, characterized in that, Along the first direction, the distance between the first surface and the second surface is H2, which satisfies: 0.3mm≤H2≤2.5mm, and optionally, 0.45mm≤H2≤0.8mm.

5. The battery cell according to claim 1, characterized in that, Along the first direction, the distance between the abutment surface and the bottom surface of the guide channel is H3, which satisfies: 0.2mm≤H3≤1.8mm, and optionally, 0.4mm≤H3≤1.6mm.

6. The battery cell according to claim 1, characterized in that, Along the first direction, the third surface is closer to the second wall than the second surface.

7. The battery cell according to claim 1, characterized in that, The hardness of the portion of the abutment located between the bottom surface of the guide channel and the third surface is greater than the hardness of the portion of the body located between the first surface and the second surface.

8. The battery cell according to any one of claims 1-6, characterized in that, The abutment portion includes a first part and a first transition portion. The first part is the bottom wall of the guide channel, and the surface of the first part facing away from the second wall is the third surface. The first transition portion connects the first part and the main body portion, and the thickness of the first transition portion is greater than the thickness of the first part.

9. The battery cell according to any one of claims 1-6, characterized in that, The first wall further includes an edge portion surrounding the outer edge of the abutment portion. Along the first direction, the abutment surface is closer to the second wall than the edge portion. The edge portion is located on the side of the side wall opposite to the second wall and is connected to the side wall.

10. The battery cell according to claim 9, characterized in that, The abutment portion includes a first part and a second transition portion. The first part is the bottom wall of the guide channel, and the surface of the first part facing away from the second wall is the third surface. The second transition portion connects the first part and the edge portion, and the thickness of the second transition portion is greater than the thickness of the first part.

11. The battery cell according to any one of claims 1-6, characterized in that, A first flow channel is formed between the sidewall and the electrode assembly, and the first flow channel is connected to the guide groove.

12. The battery cell according to any one of claims 1-6, characterized in that, The main body includes a second part and a third part. The second part connects the third part and the abutment part. Along the first direction, the third part protrudes from the second part in a direction close to the second wall. The pressure relief mechanism is disposed in the third part. The surface of the second part away from the second wall is the first surface.

13. The battery cell according to any one of claims 1-6, characterized in that, The outer casing includes a housing and an end cap. One end of the housing has an opening, and the end cap closes the opening. The end cap is the first wall, and along a first direction, the wall portion of the housing opposite to the end cap is the second wall.

14. A battery device, characterized in that, Includes the battery cell according to any one of claims 1-12.

15. An electrical appliance, characterized in that, Includes a battery cell according to any one of claims 1-12, the battery cell being used to provide electrical energy to the electrical device.

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