Battery cell, battery device and electric device

Abstract

Provided in the present application are a battery cell, a battery device and an electric device. The battery cell comprises a casing, an end cover, a pressure relief mechanism and an insulating member. The casing has an opening, and the casing has a first wall portion. The end cover closes the opening. The pressure relief mechanism is disposed on the first wall portion. The pressure relief mechanism comprises a first groove, and the pressure relief mechanism is configured to be able to crack along the first groove when the battery cell releases pressure. The insulating member is disposed on the outer side of the casing and covers at least a portion of the outer surface of the first wall portion. The insulating member is provided with a clearance opening. In the direction of thickness of the first wall portion, the orthographic projection of the first groove is located in the clearance opening. The clearance opening can provide clearance for the first groove. The insulating member does not easily suppress the deformation of the pressure relief mechanism when the battery cell releases pressure, such that the first groove can crack in a timely manner when the battery cell releases pressure, thereby being conducive to improving the pressure relief timeliness of the battery cell. A fluid medium can be directly discharged to the outer side of the battery cell through the clearance opening, thereby being conducive to improving the pressure relief rate and improving the reliability of the battery cell.

Description

Battery cells, battery packs and electrical devices 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 battery life, energy density, discharge capacity, and charge / discharge rate. Furthermore, battery reliability must also be considered. However, current batteries have relatively poor reliability.

[0003] Summary of the Invention

[0004] 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 poor battery reliability in related technologies.

[0005] In a first aspect, embodiments of this application provide a battery cell, the battery cell including a housing, an end cap, a pressure relief mechanism, and an insulating member. The housing has an opening and a first wall portion; the end cap closes the opening; the pressure relief mechanism is disposed on the first wall portion, the pressure relief mechanism includes a first groove, and the pressure relief mechanism is configured to split along the first groove when the battery cell is depressurized; the insulating member is disposed on the outside of the housing and covers at least a portion of the outer surface of the first wall portion; wherein, the insulating member is provided with a clearance opening, and the orthographic projection of the first groove is located within the clearance opening along the thickness direction of the first wall portion.

[0006] In the above technical solution, a pressure relief mechanism is provided on the first wall of the battery cell. When the internal pressure of the battery cell reaches the detonation pressure, the pressure relief mechanism can crack along the first groove to allow the fluid medium inside the battery cell to flow out and relieve pressure. An insulating member is provided on the outside of the casing. The insulating member can insulate and isolate the casing from other electrical connection components, thereby reducing the risk of short circuit and improving the reliability of the battery cell. By providing a clearance opening on the insulating member and placing the orthographic projection of the first groove along the thickness direction of the first wall within the clearance opening, the clearance opening can avoid the first groove. On the one hand, when the battery cell is depressurized, the insulating member is less likely to suppress the deformation of the pressure relief mechanism and the cracking of the first groove, allowing the first groove to crack in time when the battery cell is depressurized, which is beneficial to improving the timeliness of the battery cell's pressure relief. On the other hand, the presence of the clearance opening makes it less likely for the insulating member to block the fluid medium discharged from the pressure relief mechanism. The fluid medium can be directly discharged to the outside of the battery cell through the clearance opening, which is beneficial to improving the pressure relief rate and the reliability of the battery cell.

[0007] As an optional technical solution in this application embodiment, in the projection plane perpendicular to the thickness direction of the first wall portion, the minimum distance between the orthographic projection of the first groove and the orthographic projection of the edge of the clearance opening is A, which satisfies: 0.2mm≤A≤5mm.

[0008] In the above technical solution, when A ≥ 0.2 mm, the minimum distance between the orthographic projection of the first groove and the orthographic projection of the edge of the clearance opening is relatively large in the projection plane perpendicular to the thickness direction of the first wall. This results in a better clearance effect of the clearance opening on the first groove. When the battery cell is depressurized, the insulating component is less likely to suppress the deformation of the depressurization mechanism, allowing the first groove to crack promptly during battery cell depressurization. This improves the timeliness of battery cell depressurization, allowing the fluid medium to be directly discharged to the outside of the battery cell through the clearance opening, which improves the depressurization rate and overall reliability. Furthermore, the relatively large minimum distance between the orthographic projection of the first groove and the edge of the clearance opening in the projection plane perpendicular to the thickness direction of the first wall can also absorb assembly errors, reducing assembly requirements. When A ≤ 5 mm, the minimum distance between the orthographic projection of the first groove and the edge of the clearance opening in the projection plane perpendicular to the thickness direction of the first wall is not excessively large, preventing the clearance opening from becoming too large. This ensures the insulating component has a good insulation effect, further improving the reliability of the battery cell. Therefore, when 0.2mm≤A≤5mm, the internal pressure of the battery cell can reach the detonation pressure, which is convenient for the pressure relief mechanism to release pressure, and the insulating parts can have a good insulation effect, so that the battery cell has high reliability.

[0009] As an optional technical solution in this application embodiment, the first groove defines a predetermined pressure relief area, the pressure relief mechanism includes a second groove, the minimum residual thickness of the second groove is greater than the minimum residual thickness of the first groove, and the second groove is configured to guide at least a portion of the predetermined pressure relief area to flip over to open at least a portion of the predetermined pressure relief area.

[0010] In the above technical solution, by setting a second groove, the strength of the pressure relief mechanism at the second groove position is weakened, making it easier for the predetermined pressure relief area to flip open under the action of the fluid medium. This not only increases the probability of the predetermined pressure relief area opening, but also increases the opening speed of the predetermined pressure relief area, achieving rapid pressure relief, reducing the risk of battery cell explosion and fire, and helping to improve the reliability of the battery cell.

[0011] As an optional technical solution in this application embodiment, the orthographic projection of the second groove is located within the clearance opening along the thickness direction of the first wall portion.

[0012] In the above technical solution, by setting an avoidance opening on the insulating component and placing the orthographic projection of the second groove along the thickness direction of the first wall portion within the avoidance opening, the avoidance opening can avoid the second groove. When the battery cell is depressurized, the insulating component is less likely to prevent the predetermined depressurization area from flipping open, so that the predetermined depressurization area can flip open in time when the battery cell is depressurized. This is beneficial to improving the timeliness of depressurization of the battery cell and improving the reliability of the battery.

[0013] As an optional technical solution in this application embodiment, along the width direction of the second groove, the edge of the clearance opening has a first edge that is opposite to the second groove and closest to the second groove. In the projection plane perpendicular to the thickness direction of the first wall, the minimum distance between the orthographic projection of the second groove and the orthographic projection of the first edge along the width direction of the second groove is B, which satisfies: 0 < B ≤ 10 mm.

[0014] In the above technical solution, when the orthographic projection of the second groove is located within the clearance opening along the thickness direction of the first wall portion, and B > 0, the clearance opening can avoid the second groove. When the battery cell is depressurized, the insulating component is less likely to prevent the predetermined depressurization area from flipping open, allowing the predetermined depressurization area to flip open promptly when the battery cell is depressurized. This improves the timeliness of depressurization of the battery cell and enhances battery reliability. When the orthographic projection of the second groove is located within the clearance opening along the thickness direction of the first wall portion, and B ≤ 10mm, the minimum distance between the orthographic projection of the second groove and the orthographic projection of the first edge along the width direction of the second groove in the projection plane perpendicular to the thickness direction of the first wall portion is not too large. This prevents the clearance opening from becoming too large, resulting in better insulation performance from the insulating component and improving the reliability of the battery cell.

[0015] As an optional technical solution in this application embodiment, the insulating element covers the second groove.

[0016] In the above technical solution, when the insulating component covers the first groove, the size of the clearance opening is small, which makes the insulating component have a better insulation effect and helps to improve the reliability of the battery cell.

[0017] As an optional technical solution in this application embodiment, along the width direction of the second groove, the edge of the clearance opening has a first edge that is opposite to the second groove and closest to the second groove. In the projection plane perpendicular to the thickness direction of the first wall, the minimum distance between the orthographic projection of the second groove and the orthographic projection of the first edge along the width direction of the second groove is B, which satisfies: 0≤B≤3mm.

[0018] In the above technical solution, when the insulating component covers the second groove and B > 0, the size of the clearance opening is relatively small, resulting in better insulation performance and improving the reliability of the battery cell. When the insulating component covers the second groove and B ≤ 3mm, the size of the clearance opening is not too small, and the insulating component is less likely to prevent the predetermined pressure relief area from flipping open when the battery cell is depressurized. This allows the predetermined pressure relief area to flip open promptly when the battery cell is depressurized, improving the timeliness of pressure relief and thus enhancing battery reliability.

[0019] As an optional technical solution in this application embodiment, the first groove includes a first groove segment, a second groove segment, and a third groove segment. The second groove and the second groove segment are arranged opposite to each other along a first direction. The first groove segment and the third groove segment are arranged opposite to each other along a second direction. The second groove segment connects the first groove segment and the third groove segment. The first groove segment, the second groove segment, and the third groove segment together define at least one of the predetermined pressure relief zones. The first direction, the second direction, and the thickness direction of the first wall are perpendicular to each other.

[0020] In the above technical solution, the first groove includes a first groove segment, a second groove segment, and a third groove segment. The second groove segment connects the first groove segment and the third groove segment, so that the pressure relief mechanism can split along the first groove segment, the second groove segment, and the third groove segment when the battery cell is depressurized, thereby opening a predetermined pressure relief area to release the internal pressure of the battery cell. This structure of the first groove makes the connection points between the first and second groove segments, as well as between the first and third groove segments, weaker, making it easier to split and open the predetermined pressure relief area for pressure relief, and further increasing the pressure relief area and pressure relief rate of the battery cell. By arranging the second groove segment and the second groove opposite each other along a first direction, the predetermined pressure relief area jointly defined by the first, second, and third groove segments is more easily opened by the action of the fluid medium.

[0021] As an optional technical solution in this application embodiment, the housing includes a plurality of sidewalls, which surround the first wall portion; the insulating member includes a plurality of insulating portions and a plurality of flanged portions, each insulating portion covering at least a portion of the outer surface of one of the sidewalls, and along the thickness direction of the first wall portion, each insulating portion is provided with a flanged portion at one end near the first wall portion, the flanged portion covering a portion of the outer surface of the first wall portion, and the plurality of flanged portions defining the clearance opening.

[0022] In the above technical solution, by having each insulating part cover at least a portion of the outer surface of a sidewall, the insulation effect of the insulating component is improved. By providing a flanged portion at one end of each insulating part near the first wall portion, the flanged portion can cover a portion of the outer surface of the first wall portion, thereby reducing the risk of short circuits caused by the first wall portion contacting other electrical connection parts. Multiple flanged portions collectively define a clearance opening, resulting in a simple structure that eliminates the need for additional opening steps, thus reducing production processes and costs.

[0023] As an optional technical solution in this application embodiment, the width of the flange is L, which satisfies: L≥2mm.

[0024] In the above technical solution, when L≥2mm, the width of the flange is relatively large, which allows for sufficient creepage distance between the casing and other electrical connection components, resulting in better insulation of the insulating components. This helps reduce the risk of short circuits in the casing and improves the reliability of the battery cells.

[0025] As an optional technical solution in this application embodiment, the housing includes a plurality of sidewalls, which surround the first wall portion; the insulating member includes a first insulating portion and two second insulating portions, which are disposed opposite to each other along a first direction, the first insulating portion connects the two second insulating portions, the first insulating portion covers at least a portion of the outer surface of the first wall portion, each second insulating portion covers at least a portion of the outer surface of one sidewall, the clearance opening is a through hole provided in the first insulating portion, and the first direction is perpendicular to the thickness direction of the first wall portion.

[0026] In the above technical solution, the insulating component includes a first insulating part and two second insulating parts. The first insulating part covers a portion of the outer surface of the first wall, and each second insulating part covers at least a portion of the outer surface of a side wall. This simplifies the structure of the insulating component and facilitates its placement on the outside of the housing. The clearance opening is a through hole located in the first insulating part, making it easier to adapt the size of the clearance opening to the size of the pressure relief mechanism. This ensures the clearance opening is appropriately sized, effectively avoiding the pressure relief mechanism while maintaining good insulation performance.

[0027] As an optional technical solution in this application embodiment, the plurality of sidewalls include two second wall portions and two third wall portions disposed opposite to each other along the first direction and along the second direction, wherein the first direction, the second direction and the thickness direction of the first wall portion are perpendicular to each other; each second insulating portion covers at least a portion of the outer surface of a second wall portion; the insulating member includes a flange portion, wherein the flange portion is provided at least one end of the second insulating portion and the first insulating portion along the second direction, and the flange portion covers a portion of the outer surface of the third wall portion.

[0028] In the above technical solution, by setting a flange to cover part of the outer surface of the third wall, the insulation effect of the insulating component can be further improved, the risk of short circuit between the casing and other electrical connection components can be reduced, and the reliability of the battery cell can be improved.

[0029] As an optional technical solution in this application embodiment, along the thickness direction of the second insulating part, the minimum distance between the edge of the clearance opening and the outer surface of the second insulating part is C, which satisfies: C≥2mm.

[0030] In the above technical solution, when C≥2mm, the minimum distance between the edge of the clearance opening and the outer surface of the second insulating part along the thickness direction of the second insulating part is large, which makes the shell and other electrical connection parts have sufficient creepage distance, so that the insulating part has a better insulation effect, which helps to reduce the risk of short circuit in the shell and improve the reliability of the battery cell.

[0031] As an optional technical solution in this application embodiment, the insulating element is an insulating film covering the outer surface of the housing.

[0032] In the above technical solution, when the insulating component is an insulating film covering the outer surface of the casing, the cost of the insulating component itself is low. Furthermore, the process of coating the outer surface of the casing is simple and low-cost, which helps to reduce the cost of the battery cell.

[0033] As an optional technical solution in this application embodiment, the insulating film includes multiple insulating layers and multiple adhesive layers, the multiple insulating layers are stacked, and the insulating layers and the adhesive layers are alternately arranged along the stacking direction of the multiple insulating layers.

[0034] In the above technical solution, by setting multiple insulating layers and multiple adhesive layers, on the one hand, the insulating component has a better insulating effect; on the other hand, the insulating component has better toughness, thus facilitating film coating.

[0035] As an optional technical solution in this application embodiment, the insulating element is an insulating coating disposed on the outer surface of the housing.

[0036] In the above technical solution, the insulating coating is not easily damaged and has better insulation performance, which can effectively insulate and isolate the casing and other electrical connection components, thereby reducing the risk of short circuit and improving the reliability of the battery cell.

[0037] As an optional technical solution in this application embodiment, the thickness of the insulating component is H, which satisfies: 0.06mm≤H≤0.15mm.

[0038] In the above technical solutions, when H ≥ 0.06 mm, the insulation component has a relatively large thickness, resulting in better insulation performance, reducing the risk of short circuits in the casing, and improving the reliability of the battery cell. When H ≤ 0.15 mm, the insulation component thickness is not excessive, which helps to reduce the volume of the battery cell and increase its energy density. Therefore, when 0.06 mm ≤ H ≤ 0.15 mm, both the reliability and energy density of the battery cell can be balanced.

[0039] As an optional technical solution in this application embodiment, 0.09mm≤H≤0.13mm.

[0040] In the above technical solutions, when H ≥ 0.09 mm, the insulation component is thicker, resulting in better insulation performance, reducing the risk of short circuits in the casing, and improving the reliability of the battery cell. When H ≤ 0.13 mm, the insulation component thickness is not excessive, which helps to reduce the volume of the battery cell and increase its energy density. Therefore, when 0.06 mm ≤ H ≤ 0.15 mm, a better balance between the reliability and energy density of the battery cell can be achieved.

[0041] As an optional technical solution in this application embodiment, the pressure relief mechanism is integrally formed with the first wall portion.

[0042] In the above technical solution, the pressure relief mechanism is integrally formed with the first wall, eliminating the need for additional welding or bonding processes, which helps reduce the risk of leakage from the pressure relief mechanism. Furthermore, during production, it is easier to ensure that the detonation pressure of multiple battery cells produced is relatively consistent.

[0043] As an optional technical solution in this application embodiment, the pressure relief mechanism is separately disposed from the first wall portion, the first wall portion is provided with a pressure relief hole, and the pressure relief mechanism is installed on the first wall portion and covers the pressure relief hole.

[0044] In the above technical solution, the pressure relief mechanism is separately set and installed on the first wall portion to facilitate processing and manufacturing.

[0045] As an optional technical solution in this application embodiment, the first wall portion is a wall portion of the housing that is disposed opposite to the end cap along the thickness direction of the first wall portion.

[0046] In the above technical solution, the pressure relief mechanism is set on the wall of the housing that is opposite to the end cover along the thickness direction of the first wall. The fluid medium ejected by the pressure relief mechanism is less likely to act on other electrical connection structures on the end cover, which helps to reduce the risk of short circuit of the battery cell.

[0047] Secondly, embodiments of this application also provide a battery device, which includes the aforementioned battery cell.

[0048] 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

[0049] 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.

[0050] Figure 1 is a structural schematic diagram of a vehicle provided in some embodiments of this application;

[0051] Figure 2 is an exploded view of a battery device provided in some embodiments of this application;

[0052] Figure 3 is a schematic diagram of the structure of a battery cell provided in some embodiments of this application;

[0053] Figure 4 is an exploded view of a single battery cell provided in some embodiments of this application;

[0054] Figure 5 is an exploded view of the housing and insulation components provided in some embodiments of this application;

[0055] Figure 6 is a bottom view of a single battery cell provided in some embodiments of this application;

[0056] Figure 7 is a bottom view of a battery cell provided in some other embodiments of this application;

[0057] Figure 8 is a schematic diagram of the structure of a battery cell provided in some embodiments of this application;

[0058] Figure 9 is an exploded view of the housing and insulation provided in some other embodiments of this application;

[0059] Figure 10 is a bottom view of a battery cell provided in some embodiments of this application;

[0060] Figure 11 is a cross-sectional view of an insulating element provided in some embodiments of this application.

[0061] Icons: 10-Box body; 11-First box body; 12-Second box body; 20-Battery cell; 21-Shell; 211-First wall; 212-Side wall; 2121-Second wall; 2122-Third wall; 22-End cap; 23-Pressure relief mechanism; 231-First groove; 2311-First slot segment; 2312-Second slot segment; 2313-Third slot segment; 2314-First connecting line; 232-Second groove; 233-Predetermined pressure relief area; 24-Insulating component; 241-Insulating part; 242-Flanged part; 243-Avoidance opening; 244-First insulating part; 245-Second insulating part; 246-Insulating layer; 247-Adhesive layer; 2431-First edge; 25-Electrode assembly; 26-Electrode terminal; 100-Battery device; 200-Controller; 300-Motor; 1000-Vehicle. Detailed Implementation

[0062] 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.

[0063] 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.

[0064] 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.

[0065] 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.

[0066] 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.

[0067] 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.

[0068] In this application, "multiple" means two or more (including two).

[0069] 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.

[0070] 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.

[0071] 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.

[0072] 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.

[0073] 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.

[0074] 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.).

[0075] 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 / 3 Mn 1 / 3 O2 (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 0.05At least one of O2 and its modified compounds.

[0076] 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.

[0077] In some embodiments, the negative electrode may be a negative electrode sheet, and the negative electrode sheet may include a negative electrode current collector.

[0078] 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.).

[0079] 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.

[0080] 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.

[0081] 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.

[0082] In some embodiments, the positive current collector can be made of aluminum, and the negative current collector can be made of copper.

[0083] 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.

[0084] 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.

[0085] In some embodiments, the separator is a solid electrolyte. The solid electrolyte is disposed between the positive and negative electrodes, serving both to transport ions and to isolate the positive and negative electrodes.

[0086] 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.

[0087] 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.

[0088] 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.

[0089] Among them, the gel electrolyte includes a polymer as the electrolyte backbone network, combined with an ionic liquid - lithium salt.

[0090] Solid electrolytes include polymer solid electrolytes, inorganic solid electrolytes, and composite solid electrolytes.

[0091] As an example, polymer solid electrolytes can be polyether (polyoxyethylene), polysiloxane, polycarbonate, polyacrylonitrile, polyvinylidene fluoride, polymethyl methacrylate, monoionic polymers, polyionic liquids-lithium salts, cellulose, etc.

[0092] As an example, inorganic solid electrolytes may include one or more of the following: oxide solid electrolytes (crystalline perovskite, sodium superconducting ion conductor, garnet, amorphous LiPON thin film), sulfide solid electrolytes (crystalline lithium superconducting ion conductor (lithium germanium phosphate sulfide, silver sulfide germanium ore), amorphous sulfides), halide solid electrolytes, nitride solid electrolytes, and hydride solid electrolytes.

[0093] As an example, composite solid electrolytes are formed by adding inorganic solid electrolyte fillers to polymer solid electrolytes.

[0094] In some implementations, the electrode assembly is a wound structure. The positive and negative electrode sheets are wound into a wound structure.

[0095] In some implementations, the electrode assembly is a stacked structure.

[0096] As an example, multiple positive and negative electrodes can be set, and multiple positive and multiple negative electrodes can be stacked alternately.

[0097] 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.

[0098] As an example, both the positive and negative electrode plates are folded to form multiple stacked folded segments.

[0099] As an example, multiple separators can be provided, each positioned between any adjacent positive or negative electrode plates.

[0100] As an example, the separators can be continuously arranged, either by folding or rolling between any adjacent positive or negative electrode plates.

[0101] In some embodiments, the electrode assembly can be cylindrical, flat, or polygonal, etc.

[0102] 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.

[0103] 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, plastic (such as polypropylene), composite metal (such as copper-aluminum composite), or aluminum-plastic film, etc.

[0104] 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.

[0105] As an example, a battery cell can be a cylindrical battery cell, a prismatic battery cell, a pouch 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.

[0106] The battery apparatus 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.

[0107] 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.

[0108] As an example, a battery module can be formed by bundling multiple battery cells together with cable ties.

[0109] In some embodiments, the battery device may be a battery pack, which may include a housing and one or more individual battery cells housed within the housing.

[0110] As an example, the battery cell assembly can be a battery module, which can be housed in a housing by fixing the battery module in the housing.

[0111] As an example, battery cell assemblies can also be housed in a housing by directly fixing multiple battery cells to the housing.

[0112] 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.

[0113] 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.

[0114] 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.

[0115] 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.

[0116] 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.

[0117] The development of battery technology must consider multiple design factors simultaneously, such as energy density, cycle life, discharge capacity, and charge / discharge rate. Additionally, battery reliability must also be considered. However, current battery reliability is relatively poor.

[0118] To improve the reliability of individual battery cells, existing technologies include setting a pressure relief mechanism on the end cap of the battery cell. This mechanism has grooves that allow the pressure relief mechanism to crack along the grooves when the internal pressure of the battery cell reaches the burst pressure, thereby releasing the internal pressure of the battery cell and reducing the risk of explosion and fire.

[0119] To reduce the risk of short circuits caused by the fluid medium ejected from the pressure relief mechanism acting on other electrical connection structures on the end cap, the pressure relief mechanism can be installed on one wall of the housing. However, when the pressure relief mechanism is installed on one wall of the housing, it often cannot relieve pressure in a timely manner.

[0120] Research has revealed that the battery cell includes an insulating component located on the outside of the casing. This insulating component covers the pressure relief mechanism, which often fails to release pressure in a timely manner, resulting in poor battery reliability.

[0121] In view of this, embodiments of this application provide a battery cell, which includes a housing, an end cap, a pressure relief mechanism, and an insulating member. The housing has an opening and a first wall. The end cap closes the opening. The pressure relief mechanism is disposed on the first wall. The pressure relief mechanism includes a first groove and is configured to split along the first groove when the battery cell is depressurized. The insulating member is disposed on the outside of the housing and covers at least a portion of the outer surface of the first wall. The insulating member has a clearance opening, and the orthographic projection of the first groove is located within the clearance opening along the thickness direction of the first wall.

[0122] A pressure relief mechanism is provided on the first wall of the battery cell. When the internal pressure of the battery cell reaches the detonation pressure, the pressure relief mechanism can crack along the first groove to allow the fluid medium inside the battery cell to flow out and relieve pressure. An insulating member is provided on the outside of the casing. The insulating member can insulate and isolate the casing from other electrical connection components, thereby reducing the risk of short circuit and improving the reliability of the battery cell. By providing a clearance opening on the insulating member and placing the orthographic projection of the first groove along the thickness direction of the first wall within the clearance opening, the clearance opening can avoid the first groove. On the one hand, when the battery cell is depressurized, the insulating member is less likely to suppress the deformation of the pressure relief mechanism and the cracking of the first groove, allowing the first groove to crack in time when the battery cell is depressurized, which is beneficial to improving the timeliness of the battery cell's pressure relief. On the other hand, the presence of the clearance opening makes it less likely for the insulating member to block the fluid medium discharged from the pressure relief mechanism. The fluid medium can be directly discharged to the outside of the battery cell through the clearance opening, which is beneficial to improving the pressure relief rate and the reliability of the battery cell.

[0123] 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.

[0124] For ease of explanation, the following embodiments will use a vehicle as an example of an electrical device.

[0125] Please refer to Figure 1, which is a structural schematic diagram 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.

[0126] 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.

[0127] 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.

[0128] Please refer to Figure 2, which 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, with the housing 10 used to house the battery cells 20.

[0129] 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 space.

[0130] 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.

[0131] 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.

[0132] Please refer to Figures 3, 4, 5, and 6. Figure 3 is a structural schematic diagram of a battery cell 20 provided in some embodiments of this application. Figure 4 is an exploded view of a battery cell 20 provided in some embodiments of this application. Figure 5 is an exploded view of a housing 21 and an insulating member 24 provided in some embodiments of this application. Figure 6 is a bottom view of a battery cell 20 provided in some embodiments of this application. This application provides a battery cell 20, which includes a housing 21, an end cap 22, a pressure relief mechanism 23, and an insulating member 24. The housing 21 has an opening and a first wall portion 211. The end cap 22 closes the opening. The pressure relief mechanism 23 is disposed on the first wall portion 211 and includes a first groove 231. The pressure relief mechanism 23 is configured to split along the first groove 231 when the battery cell 20 is depressurized. The insulating member 24 is disposed on the outside of the housing 21 and covers at least a portion of the outer surface of the first wall portion 211. The insulating component 24 is provided with a clearance opening 243, and the orthographic projection of the first groove 231 is located within the clearance opening 243 along the thickness direction of the first wall portion 211.

[0133] Battery cell 20 refers to the smallest unit that makes up battery device 100.

[0134] The housing 21 has an open-end receiving space for accommodating the electrode assembly 25. An end cap 22 is attached to the housing 21 and closes the opening. Here, "closed" refers to covering or shutting off; it can be either sealed or unsealed.

[0135] End cap 22 refers to a component that covers the opening of housing 21 to isolate the internal environment of battery cell 20 from the external environment. The shape of end cap 22 can be adapted to the shape of housing 21 to fit it. Optionally, end cap 22 can be made of a material with certain hardness and strength (such as aluminum alloy), so that end cap 22 is not easily deformed under pressure and impact, giving battery cell 20 higher structural strength and improved reliability. The material of end cap 22 can include, but is not limited to, copper, iron, aluminum, stainless steel, aluminum alloy, and plastic. End cap 22 is also provided with electrode terminals 26, which are used for electrical connection with the tabs of electrode assembly 25 to input or output electrical energy to battery cell 20. Electrode terminals 26 and tabs can be directly connected, for example, by direct welding. Electrode terminals 26 and tabs can also be indirectly connected, for example, by indirect connection through current collectors. The battery cell 20 also includes a lower plastic layer disposed inside the end cap 22. The lower plastic layer can be used to isolate the electrical connection components within the housing 21 from the end cap 22 to reduce the risk of short circuits. For example, the lower plastic layer can be plastic, rubber, etc.

[0136] Electrode assembly 25 is the component in the battery cell 20 where electrochemical reactions occur. The housing 21 may contain one or more electrode assemblies 25. The electrode assembly 25 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 of the electrode assembly 25, while the portions of the positive and negative electrode sheets without active material each constitute a tab. The positive and negative tabs may be located together at one end of the main body or separately at both ends of the main body. During the charging and discharging process of the battery cell 20, the positive and negative active materials react with the electrolyte.

[0137] The first wall portion 211 is a wall portion of the housing 21. In Figures 3, 4, 5, and 6, the first wall portion 211 is the bottom wall of the housing 21 that is disposed opposite to the end cap 22. In other embodiments, the first wall portion 211 may also be a side wall 212 of the housing 21 that is adjacent to and connected to the end cap 22.

[0138] The pressure relief mechanism 23 is a component used to open when the internal pressure or temperature of the battery cell 20 reaches the burst pressure, thereby releasing the internal pressure of the battery cell 20. The pressure relief mechanism 23 can be a component mounted on the first wall portion 211, in which case the pressure relief mechanism 23 and the first wall portion 211 are separately configured and connected. For example, the pressure relief mechanism 23 can be an explosion-proof plate mounted on the first wall portion 211. The pressure relief mechanism 23 can also be a part of the first wall portion 211, in which case the pressure relief mechanism 23 and the first wall portion 211 are integrally formed. The location of the pressure relief mechanism 23 can be used to determine which wall of the housing 21 is the first wall portion 211. For example, when the pressure relief mechanism 23 is located on the bottom wall of the housing 21, the bottom wall is the first wall portion 211. When the pressure relief mechanism 23 is located on a side wall 212 of the housing 21, that side wall 212 is the first wall portion 211.

[0139] The first groove 231 serves to relieve pressure, allowing the pressure relief mechanism 23 to crack along the first groove 231 when the internal pressure or temperature of the battery cell 20 reaches the burst pressure, thereby releasing the internal pressure of the battery cell 20.

[0140] Optionally, the first groove 231 may be provided on the side of the pressure relief mechanism 23 away from the inside of the housing 21, or it may be provided on the side of the pressure relief mechanism 23 facing the inside of the housing 21. For example, in Figures 5 and 6, the first groove 231 is provided on the side of the pressure relief mechanism 23 away from the inside of the housing 21, that is, the first groove 231 is provided on the surface of the side of the pressure relief mechanism 23 away from the inside of the housing 21.

[0141] The insulating member 24 has an insulating function and is disposed on the outside of the housing 21 to reduce the risk of short circuit due to contact between the housing 21 and other electrical connection components. The insulating member 24 may cover a portion of the outer surface of the first wall portion 211, or it may completely cover the outer surface of the first wall portion 211.

[0142] In some embodiments, the insulating element 24 is an insulating film that covers the outer side of the housing 21. The insulating element 24 can be made of plastic, rubber, etc. For example, the insulating element is a blue film. In other embodiments, the insulating element 24 is an insulating coating that is applied to the outer surface of the housing 21.

[0143] Please refer to Figure 5. The thickness direction of the first wall portion 211 can be the X direction shown in the figure.

[0144] The clearance opening 243 is a structure used to avoid the first groove 231. For example, the clearance opening 243 can be a through hole provided in the insulating member 24. The orthographic projection of the first groove 231 along the thickness direction of the first wall portion 211 is located inside the clearance opening 243. In other words, along the thickness direction of the first wall portion 211, the orthographic projection of the edge of the first groove 231 surrounds the outside of the clearance opening 243.

[0145] A pressure relief mechanism 23 is provided on the first wall portion 211 of the battery cell 20. When the internal pressure of the battery cell 20 reaches the detonation pressure, the pressure relief mechanism 23 can crack along the first groove 231 to allow the fluid medium inside the battery cell 20 to flow out and relieve pressure. An insulating member 24 is provided on the outside of the housing 21. The insulating member 24 can insulate and isolate the housing 21 from other electrical connection components, thereby reducing the risk of short circuit and improving the reliability of the battery cell 20. By providing a clearance opening 243 on the insulating member 24 and placing the orthographic projection of the first groove 231 along the thickness direction of the first wall portion 211 within the clearance opening 243, the clearance opening 243 can avoid the first groove 231. On the one hand, when the battery cell 20 is depressurized, the insulating member 24 is less likely to suppress the deformation of the pressure relief mechanism 23 and the cracking of the first groove 231, so that the first groove 231 can crack in time when the battery cell 20 is depressurized, which is beneficial to improving the timeliness of the pressure relief of the battery cell 20. On the other hand, the presence of the clearance port 243 makes it less likely for the insulating component 24 to block the fluid medium discharged from the pressure relief mechanism 23. The fluid medium can be directly discharged to the outside of the battery cell 20 through the clearance port 243, which is beneficial to improving the pressure relief rate and the reliability of the battery cell 20.

[0146] Referring to Figures 3, 4, 5, and 6, in some embodiments, the minimum distance A between the orthographic projection of the first groove 231 and the orthographic projection of the edge of the clearance opening 243 in the projection plane perpendicular to the thickness direction of the first wall portion 211 satisfies: 0.2mm≤A≤5mm.

[0147] A represents the minimum distance between the orthographic projection of the first groove 231 in the projection plane perpendicular to the thickness direction of the first wall portion 211 and the orthographic projection of the edge of the clearance opening 243 in the projection plane perpendicular to the thickness direction of the first wall portion 211.

[0148] The minimum distance between the orthographic projection of the first groove 231 in the projection plane perpendicular to the thickness direction of the first wall portion 211 and the orthographic projection of the edge of the clearance opening 243 in the projection plane perpendicular to the thickness direction of the first wall portion 211 can be: A = 0.2mm, 0.5mm, 1mm, 1.5mm, 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm, 5mm, etc.

[0149] When A ≥ 0.2 mm, in the projection plane perpendicular to the thickness direction of the first wall portion 211, the minimum distance between the orthographic projection of the first groove 231 and the orthographic projection of the edge of the clearance opening 243 is relatively large. This results in a better clearance effect of the clearance opening 243 on the first groove 231. When the battery cell 20 is depressurized, the insulating component 24 is less likely to suppress the deformation of the depressurization mechanism 23, allowing the first groove 231 to crack promptly during depressurization of the battery cell 20. This improves the timeliness of depressurization of the battery cell 20, allowing the fluid medium to be directly discharged to the outside of the battery cell 20 through the clearance opening 243, which helps to increase the depressurization rate and improve the reliability of the battery cell 20. Furthermore, the larger minimum distance between the orthographic projection of the first groove 231 and the orthographic projection of the edge of the clearance opening 243 in the projection plane perpendicular to the thickness direction of the first wall portion 211 also helps to absorb assembly errors, reducing assembly requirements. When A ≤ 5mm, the minimum distance between the orthographic projection of the first groove 231 and the orthographic projection of the edge of the clearance opening 243 in the projection plane perpendicular to the thickness direction of the first wall portion 211 is not too large, and the clearance opening 243 is not too large, so that the insulating component 24 has a good insulation effect, which is beneficial to improving the reliability of the battery cell 20. Therefore, when 0.2mm ≤ A ≤ 5mm, the internal pressure of the battery cell 20 can reach the detonation pressure to facilitate the pressure relief mechanism 23 to relieve pressure, and the insulating component 24 can also have a good insulation effect, so that the battery cell 20 has high reliability.

[0150] Referring to Figures 3, 4, 5, and 6, in some embodiments, a first groove 231 defines a predetermined pressure relief region 233. The pressure relief mechanism 23 includes a second groove 232, the minimum residual thickness of which is greater than the minimum residual thickness of the first groove 231. The second groove 232 is configured to guide at least a portion of the predetermined pressure relief region 233 to flip, thereby opening at least a portion of the predetermined pressure relief region 233.

[0151] The first groove 231 defines a predetermined pressure relief area 233. When the battery cell 20 is depressurized, the first groove 231 cracks along the edge of the predetermined pressure relief area 233, allowing the predetermined pressure relief area 233 to open and release pressure. The first groove 231 can be an annular groove, for example, a circular annular groove or an elliptical annular groove. The first groove 231 can also be a non-annular groove, for example, a C-shaped groove or a U-shaped groove. The area enclosed by the first groove 231 is the predetermined pressure relief area 233, wherein the area enclosed by the first groove 231 is the area where the pressure relief mechanism 23 forms an opening after the first groove 231 is broken by the fluid medium inside the housing 21. When the first groove 231 is an annular groove, the area enclosed by the first groove 231 is the area enclosed by the annular groove; when the first groove 231 is a non-annular groove, the area enclosed by the first groove 231 is the area enclosed by the line connecting the free ends of the first groove 231.

[0152] The second groove 232 serves to guide at least a portion of the predetermined pressure relief zone 233 to flip open. The depth of the first groove 231 is greater than the depth of the second groove 232, such that the minimum residual thickness of the second groove 232 is greater than the minimum residual thickness of the first groove 231. "Minimum residual thickness of the first groove 231" refers to the minimum thickness of the pressure relief mechanism 23 at the location where the first groove 231 is located. "Minimum residual thickness of the second groove 232" refers to the minimum thickness of the pressure relief mechanism 23 at the location where the second groove 232 is located.

[0153] When the battery cell 20 is depressurized, the depressurization mechanism 23 first splits along the first groove 231 to allow the fluid medium inside the battery cell 20 to flow out and release pressure. Then, under the action of the fluid medium, the predetermined depressurization area 233 can be rotated outward about the second groove 232 as the rotation axis to open a larger opening and achieve rapid depressurization.

[0154] The second groove 232 may be located on the same side of the pressure relief mechanism 23 as the first groove 231, or it may be located on both sides of the pressure relief mechanism 23. For example, in Figures 5 and 6, the first groove 231 and the second groove 232 are respectively located on both sides of the pressure relief mechanism 23. The first groove 231 is located on the side of the pressure relief mechanism 23 away from the inside of the housing 21, and the second groove 232 is located on the side of the pressure relief mechanism 23 facing the inside of the housing 21.

[0155] Please refer to Figure 6. To make it easier to show the position of the second groove 232, the second groove 232 is shown in dashed lines in the figure.

[0156] For example, both the first groove 231 and the second groove 232 are formed by a stamping process.

[0157] By setting the second groove 232, the strength of the pressure relief mechanism 23 at the second groove 232 position is weakened, making the predetermined pressure relief area 233 easier to flip open under the action of the fluid medium. This not only increases the probability of the predetermined pressure relief area 233 opening, but also increases the opening speed of the predetermined pressure relief area 233, achieving rapid pressure relief, reducing the risk of battery cell 20 explosion and fire, and helping to improve the reliability of battery cell 20.

[0158] Referring to Figures 3, 4, 5 and 6, in some embodiments, the orthographic projection of the second groove 232 is located within the clearance opening 243 along the thickness direction of the first wall portion 211.

[0159] The orthographic projection of the second groove 232 along the thickness direction of the first wall portion 211 is located within the clearance opening 243. That is, the edge of the clearance opening 243 is arranged around the outside of the second groove 232 along the orthographic projection of the first wall portion 211. In this way, the clearance opening 243 can avoid the second groove 232, that is, the insulating member 24 does not cover the second groove 232.

[0160] By providing a clearance opening 243 on the insulating member 24 and placing the orthographic projection of the second groove 232 along the thickness direction of the first wall portion 211 within the clearance opening 243, the clearance opening 243 can avoid the second groove 232. When the battery cell 20 is depressurized, the insulating member 24 is less likely to prevent the predetermined depressurization area 233 from flipping open, so that the predetermined depressurization area 233 can flip open in time when the battery cell 20 is depressurized. This is beneficial to improving the timeliness of depressurization of the battery cell 20 and improving the reliability of the battery.

[0161] Referring to Figures 3, 4, 5, and 6, in some embodiments, along the width direction of the second groove 232, the edge of the clearance opening 243 has a first edge 2431 that is opposite to and closest to the second groove 232. In a projection plane perpendicular to the thickness direction of the first wall portion 211, the minimum distance B between the orthographic projection of the second groove 232 and the orthographic projection of the first edge 2431 along the width direction of the second groove 232 satisfies: 0 < B ≤ 10 mm.

[0162] Please refer to Figure 6. The width direction of the second groove 232 is the Z direction shown in the figure.

[0163] The first edge 2431 is the edge of the clearance opening 243 closest to the second groove 232. Along the width direction of the second groove 232, the first edge 2431 is positioned opposite to the second groove 232. Referring to Figure 6, in the embodiment shown in Figure 6, the pressure relief mechanism 23 includes two second grooves 232, which are arranged along the width direction of the first wall portion 211. Correspondingly, the clearance opening 243 has two first edges 2431, with one first edge 2431 corresponding to one second groove 232.

[0164] B represents the minimum distance along the width direction of the second groove 232 between the orthographic projection of the second groove 232 in a projection plane perpendicular to the thickness direction of the first wall portion 211 and the orthographic projection of the first edge 2431 in a projection plane perpendicular to the thickness direction of the first wall portion 211. During measurement, the distance between the second groove 232 and its corresponding first edge 2431 needs to be measured.

[0165] When the orthographic projection of the second groove 232 is located within the clearance opening 243 along the thickness direction of the first wall portion 211, the minimum distance between the orthographic projection of the second groove 232 and the orthographic projection of the first edge 2431 along the width direction of the second groove 232 in the projection plane perpendicular to the thickness direction of the first wall portion 211 can be: B = 0.5mm, 1mm, 1.5mm, 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm, 5mm, 5.5mm, 6mm, 6.5mm, 7mm, 7.5mm, 8mm, 8.5mm, 9mm, 9.5mm, 10mm, etc.

[0166] When the orthographic projection of the second groove 232 along the thickness direction of the first wall portion 211 is located within the clearance opening 243, and B > 0, the clearance opening 243 can avoid the second groove 232. When the battery cell 20 is depressurized, the insulating member 24 is less likely to prevent the predetermined depressurization area 233 from flipping open, allowing the predetermined depressurization area 233 to flip open promptly when the battery cell 20 is depressurized. This improves the timeliness of depressurization of the battery cell 20 and enhances battery reliability. When the orthographic projection of the second groove 232 along the thickness direction of the first wall portion 211 is located within the clearance opening 243, and B ≤ 10mm, in the projection plane perpendicular to the thickness direction of the first wall portion 211, the minimum distance between the orthographic projection of the second groove 232 and the orthographic projection of the first edge 2431 along the width direction of the second groove 232 is not too large. This prevents the clearance opening 243 from becoming too large, resulting in better insulation of the insulating member 24 and enhancing the reliability of the battery cell 20.

[0167] Please refer to Figure 7, which is a bottom view schematic diagram of the battery cell 20 provided in some other embodiments of this application. In some other embodiments, the insulating member 24 covers the second groove 232.

[0168] When the insulating member 24 covers the second groove 232, the orthographic projection of the second groove 232 along the thickness direction of the first wall portion 211 is located outside the clearance opening 243. In this way, the clearance opening 243 does not avoid the second groove 232.

[0169] When the insulating component 24 covers the first groove 231, the size of the clearance opening 243 is small, which makes the insulating component 24 have a better insulation effect, which is beneficial to improving the reliability of the battery cell 20.

[0170] Referring to Figure 7, in some embodiments, along the width direction of the second groove 232, the edge of the clearance opening 243 has a first edge 2431 that is opposite to and closest to the second groove 232. In a projection plane perpendicular to the thickness direction of the first wall portion 211, the minimum distance B between the orthographic projection of the second groove 232 and the orthographic projection of the first edge 2431 along the width direction of the second groove 232 satisfies: 0 ≤ B ≤ 3 mm.

[0171] The first edge 2431 is the edge of the clearance opening 243 closest to the second groove 232. Along the width direction of the second groove 232, the first edge 2431 is positioned opposite to the second groove 232. Referring to Figure 6, in the embodiment shown in Figure 6, the pressure relief mechanism 23 includes two second grooves 232, arranged along the width direction of the first wall portion 211. Correspondingly, the clearance opening 243 has two first edges 2431, with one first edge 2431 corresponding to one second groove 232. B represents the minimum distance along the width direction of the second groove 232 between the orthographic projection of the second groove 232 in a projection plane perpendicular to the thickness direction of the first wall portion 211 and the orthographic projection of the first edge 2431 in a projection plane perpendicular to the thickness direction of the first wall portion 211. During measurement, the distance between the second groove 232 and its corresponding first edge 2431 needs to be measured.

[0172] When the insulating member 24 covers the second groove 232, the minimum distance between the orthographic projection of the second groove 232 and the orthographic projection of the first edge 2431 along the width direction of the second groove 232 in the projection plane perpendicular to the thickness direction of the first wall portion 211 can be: B = 0, 0.2mm, 0.5mm, 0.8mm, 1mm, 1.2mm, 1.5mm, 1.8mm, 2mm, 2.2mm, 2.5mm, 2.8mm, 3mm, etc.

[0173] When the insulating member 24 covers the second groove 232 and B > 0, the size of the clearance opening 243 is relatively small, resulting in better insulation performance of the insulating member 24, which is beneficial to improving the reliability of the battery cell 20. When the insulating member 24 covers the second groove 232 and B ≤ 3mm, the size of the clearance opening 243 is not too small, and the insulating member 24 is less likely to prevent the predetermined pressure relief area 233 from flipping open when the battery cell 20 is depressurized. This allows the predetermined pressure relief area 233 to flip open in a timely manner when the battery cell 20 is depressurized, which is beneficial to improving the timeliness of pressure relief of the battery cell 20 and thus improving the reliability of the battery.

[0174] Referring to Figure 7, in some embodiments, the first groove 231 includes a first groove segment 2311, a second groove segment 2312, and a third groove segment 2313. The second groove 232 is disposed opposite to the second groove segment 2312 along a first direction, and the first groove segment 2311 and the third groove segment 2313 are disposed opposite to each other along a second direction. The second groove segment 2312 connects the first groove segment 2311 and the third groove segment 2313. The first groove segment 2311, the second groove segment 2312, and the third groove segment 2313 together define at least one predetermined pressure relief zone 233. The first direction, the second direction, and the thickness direction of the first wall portion 211 are perpendicular to each other.

[0175] Please refer to Figure 7. The first direction is the Z direction shown in the figure, and the second direction is the Y direction shown in the figure. The first direction, the second direction, and the thickness direction of the first wall portion 211 are perpendicular to each other.

[0176] The first groove segment 2311 and the third groove segment 2313 are spaced apart along the second direction and are at least partially opposite each other. Optionally, both the first groove segment 2311 and the third groove segment 2313 extend along the width direction of the first wall portion 211.

[0177] The second slot segment 2312 connects the first slot segment 2311 and the third slot segment 2313. That is, the second slot segment 2312 is located between the first slot segment 2311 and the third slot segment 2313, and the two ends of the second slot segment 2312 are respectively connected to the first slot segment 2311 and the third slot segment 2313. Of course, in other embodiments, the two ends of the second slot segment 2312 can extend out of the first slot segment 2311 and the third slot segment 2313 respectively.

[0178] Referring to Figure 7, the line connecting the free end of the first groove segment 2311 and the free end of the second groove segment 2312 is the first connecting line 2314. The first connecting line 2314 is arranged opposite to the second groove segment 2312 along the width direction of the first wall portion 211. The enclosed area formed by the first groove segment 2311, the second groove segment 2312, the third groove segment 2313, and the first connecting line 2314 is the predetermined pressure relief zone 233. In other words, the first groove segment 2311, the second groove segment 2312, and the third groove segment 2313 are arranged along the edge of the predetermined pressure relief area 233, so that the predetermined pressure relief area 233 can be opened with the first groove segment 2311, the second groove segment 2312, and the third groove segment 2313 as the boundary. That is, the predetermined pressure relief area 233 is formed in the area enclosed by the first groove segment 2311, the second groove segment 2312, and the third groove segment 2313, so that the part of the pressure relief mechanism 23 located in the predetermined pressure relief area 233 can be opened with the first groove segment 2311, the second groove segment 2312, and the third groove segment 2313 as the boundary when the battery cell 20 is depressurized, thereby releasing the internal pressure of the battery cell 20.

[0179] Referring to Figure 7, the first groove 231 defines two predetermined pressure relief areas 233, which are located on both sides of the second groove segment 2312. Each predetermined pressure relief area 233 is provided with at least one second groove 232. The shape of the first groove 231 formed by the first groove segment 2311, the second groove segment 2312, and the third groove segment 2313 can be an "H" shape to form two predetermined pressure relief areas 233 on the pressure relief mechanism 23, and the two predetermined pressure relief areas 233 are located on both sides of the second groove segment 2312.

[0180] Each predetermined pressure relief zone 233 may be provided with one, two, three, or more second grooves 232, as shown in Figure 7. Each predetermined pressure relief zone 233 is provided with one second groove 232.

[0181] The first groove 231 defines two predetermined pressure relief areas 233. Each predetermined pressure relief area 233 is provided with at least one second groove 232. When the battery cell 20 is depressurized, the two predetermined pressure relief areas 233 are flipped open under the guidance of their corresponding second grooves 232, so that the battery cell 20 has a larger pressure relief area, which is beneficial to improving the pressure relief rate of the battery cell 20 and improving the reliability of the battery cell 20.

[0182] The first groove 231 includes a first groove segment 2311, a second groove segment 2312, and a third groove segment 2313. The second groove segment 2312 connects the first groove segment 2311 and the third groove segment 2313, so that the pressure relief mechanism 23 can crack along the first groove segment 2311, the second groove segment 2312, and the third groove segment 2313 when the battery cell 20 is depressurized, so as to open the predetermined pressure relief area 233 to release the internal pressure of the battery cell 20. The first groove 231 with this structure makes the connection position of the first groove segment 2311 and the second groove segment 2312 and the connection position of the first groove segment 2311 and the third groove segment 2313 weaker, making it easier to crack and open the predetermined pressure relief area 233 for pressure relief, and can further improve the pressure relief area and pressure relief rate of the battery cell 20. By arranging the second groove segment 2312 and the second recess 232 opposite to each other in the first direction, the predetermined pressure relief zone 233, which is jointly defined by the first groove segment 2311, the second groove segment 2312 and the third groove segment 2313, can be more easily flipped open under the action of the fluid medium.

[0183] Referring again to Figures 4 and 5, in some embodiments, the housing 21 includes a plurality of sidewalls 212 surrounding the first wall portion 211. The insulating member 24 includes a plurality of insulating portions 241 and a plurality of flanges 242. Each insulating portion 241 covers at least a portion of the outer surface of one of the sidewalls 212. Along the thickness direction of the first wall portion 211, each insulating portion 241 has a flange 242 at one end near the first wall portion 211. The flanges 242 cover a portion of the outer surface of the first wall portion 211, and the plurality of flanges 242 define a clearance opening 243.

[0184] The shell 21 includes multiple integrally formed side walls 212 and bottom wall, that is, the shell 21 is manufactured by an integral forming process, such as stamping, casting or extrusion molding, etc. In other words, the multiple side walls 212 and bottom wall of the shell 21 are an integral structure.

[0185] Multiple sidewalls 212 are arranged circumferentially along the first wall portion 211, and the multiple sidewalls 212 are connected end to end to form a cylindrical structure. One end of each sidewall 212 is connected to the bottom wall, and the other end of each sidewall 212 is connected to the end cap 22. The ends of the multiple sidewalls 212 away from the bottom wall together define the opening of the housing 21.

[0186] Please refer to Figures 4, 5 and 6. In the embodiment shown in the figures, the first wall portion 211 is the bottom wall of the housing 21 that is disposed opposite to the end cap 22 in the thickness direction of the first wall portion 211.

[0187] The insulating member 24 includes a plurality of insulating portions 241, which are disposed one-to-one with the sidewalls 212. Each insulating portion 241 covers part or all of the outer surface of a sidewall 212.

[0188] The flange portion 242 is provided in a one-to-one correspondence with the insulating portion 241. Each insulating portion 241 has a flange portion 242 provided at one end of the first wall portion 211 along the thickness direction of the first wall portion 211. Each flange portion 242 covers a part of the outer surface of the first wall portion 211, and multiple flange portions 242 together define the clearance opening 243.

[0189] By having each insulating portion 241 cover at least a portion of the outer surface of a sidewall 212, the insulation effect of the insulating member 24 is improved. By providing a flange 242 at one end of each insulating portion 241 near the first wall portion 211, the flange 242 can cover a portion of the outer surface of the first wall portion 211, thereby reducing the risk of short circuits caused by the first wall portion 211 contacting other electrical connections. Multiple flanges 242 together define a clearance opening 243, resulting in a simple structure that eliminates the need for additional opening steps, thus reducing production processes and costs.

[0190] Please refer to Figures 4, 5 and 6. In some embodiments, the width of the flange 242 is L, which satisfies: L≥2mm.

[0191] L represents the width of the flange 242. During measurement, multiple measurements can be taken and the average value can be used as L. In addition, when the insulating member 24 is an insulating film, in order to facilitate measurement, the insulating member 24 can be removed from the housing 21, and the distance between the crease where the flange 242 connects to the insulating member 241 and the end of the flange 242 away from the insulating member 241 can be measured.

[0192] The width of the flange 242 can be: L = 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm, 5mm, etc.

[0193] When L≥2mm, the width of the flange 242 is relatively large, which allows for sufficient creepage distance between the housing 21 and other electrical connection components, resulting in better insulation of the insulating component 24. This helps reduce the risk of short circuit in the housing 21 and improves the reliability of the battery cell 20.

[0194] Please refer to Figures 8, 9 and 10. Figure 8 is a schematic diagram of the structure of a battery cell 20 provided in some embodiments of this application.

[0195] Figure 9 is an exploded view of the housing 21 and the insulating member 24 provided in some embodiments of this application. Figure 10 is a bottom view of the battery cell 20 provided in some embodiments of this application. In some embodiments, the housing 21 includes a plurality of sidewalls 212 surrounding a first wall portion 211. The insulating member 24 includes a first insulating portion 244 and two second insulating portions 245, the two second insulating portions 245 being disposed opposite each other along a first direction, and the first insulating portion 244 connecting the two second insulating portions 245. The first insulating portion 244 covers a portion of the outer surface of the first wall portion 211, and each second insulating portion 245 covers at least a portion of the outer surface of a sidewall 212. The clearance opening 243 is a through hole provided in the first insulating portion 244, and the first direction is perpendicular to the thickness direction of the first wall portion.

[0196] The housing 21 includes multiple integrally formed sidewalls 212 and a bottom wall, meaning the housing 21 is manufactured using an integral forming process, such as stamping, casting, or extrusion molding. In other words, the multiple sidewalls 212 and the bottom wall of the housing 21 are a single, integral structure. The multiple sidewalls 212 are arranged circumferentially along the first wall portion 211, and are connected end-to-end to form a cylindrical structure. One end of each sidewall 212 is connected to the bottom wall, and the other end of each sidewall 212 is connected to the end cap 22. The ends of the multiple sidewalls 212 away from the bottom wall collectively define the opening of the housing 21. Referring to Figures 8, 9, and 10, in the embodiment shown in the figures, the first wall portion 211 is the bottom wall of the housing 21, which is disposed opposite to the end cap 22 in the thickness direction of the first wall portion 211.

[0197] The first insulating portion 244 is the portion of the insulating member 24 that covers the outer surface of the first wall portion 211. The first insulating portion 244 may cover a portion of the outer surface of the first wall portion 211, or the first insulating portion 244 may completely cover the outer surface of the first wall portion 211.

[0198] The insulating member 24 also includes two opposing second insulating portions 245, with a first insulating portion 244 connecting the two second insulating portions 245. The two opposing second insulating portions 245 respectively cover the outer surfaces of two opposing sidewalls 212. Each second insulating portion 245 may cover a portion of the outer surface of a sidewall 212, or each second insulating portion 245 may completely cover the outer surface of a sidewall 212.

[0199] The clearance opening 243 is a through hole provided in the first insulating part 244, and the through hole penetrates the first insulating part 244 along the thickness direction of the wall.

[0200] The insulating member 24 includes a first insulating portion 244 and two second insulating portions 245. The first insulating portion 244 covers a portion of the outer surface of the first wall portion 211, and each second insulating portion 245 covers at least a portion of the outer surface of a side wall 212. This design simplifies the structure of the insulating member 24, making it easy to place it on the outside of the housing 21. The clearance opening 243 is a through hole located in the first insulating portion 244, allowing its size to be more easily adapted to the size of the pressure relief mechanism 23. This ensures that the clearance opening 243 is appropriately sized, effectively avoiding the pressure relief mechanism 23 while maintaining good insulation performance of the insulating member 24.

[0201] Referring to Figures 8, 9, and 10, in some embodiments, the plurality of sidewalls 212 include two second wall portions 2121 disposed opposite each other along a first direction and two third wall portions 2122 disposed opposite each other along a second direction, wherein the first direction, the second direction, and the thickness direction of the first wall portion 211 are perpendicular to each other. Each second insulating portion 245 covers at least a portion of the outer surface of a second wall portion 2121. The insulating member 24 includes a flange portion 242, which is provided at least at one end of the second insulating portion 245 and the first insulating portion 244 along the second direction, and the flange portion 242 covers a portion of the outer surface of the third wall portion 2122.

[0202] Please refer to Figure 9. The first direction is the Z direction shown in the figure, and the second direction is the Y direction shown in the figure. The first direction, the second direction, and the thickness direction of the first wall portion 211 are perpendicular to each other.

[0203] The plurality of sidewalls 212 include two second wall portions 2121 and two third wall portions 2122, wherein the two second wall portions 2121 are disposed opposite each other along a first direction, and the two third wall portions 2122 are disposed opposite each other along a second direction. The two second wall portions 2121 and the two third wall portions 2122 are connected end to end. Two second insulating portions 245 respectively cover at least a portion of the outer surface of the two second wall portions 2121.

[0204] The first insulating portion 244 is provided with a flange portion 242 at one or both ends along the second direction, and the second insulating portion 245 is also provided with a flange portion 242 at one or both ends along the second direction. Each flange portion 242 covers a portion of the outer surface of the third wall portion 2122.

[0205] Optionally, the second wall portion 2121 is the large surface of the shell 21 (the wall portion with the largest area on the outer surface of the shell 21), and the third wall portion 2122 is the small surface of the shell 21 (the wall portion with the smallest area on the outer surface of the shell 21).

[0206] By providing a flange 242 that covers at least a portion of the outer surface of the third wall portion 2122, the insulation effect of the insulating member 24 can be further improved, the risk of short circuit between the housing 21 and other electrical connection components can be reduced, and the reliability of the battery cell 20 can be improved.

[0207] Referring to Figures 8, 9, and 10, in some embodiments, the minimum distance between the edge of the clearance opening 243 and the outer surface of the second insulating portion 245 along the thickness direction of the second insulating portion 245 is C, which satisfies: C≥2mm.

[0208] Please refer to Figure 9. The thickness direction of the second insulating part 245 is the Z direction shown in the figure.

[0209] C represents the minimum distance between the edge of the clearance 243 and the outer surface of the second insulating part 245 along the thickness direction of the second insulating part 245. During measurement, multiple measurements can be taken and the average value can be used as C.

[0210] The minimum distance between the edge of the clearance opening 243 and the outer surface of the second insulating part 245 along the thickness direction of the second insulating part 245 can be: C = 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm, 5mm, etc.

[0211] When C≥2mm, the minimum distance between the edge of the clearance 243 and the outer surface of the second insulating part 245 along the thickness direction of the second insulating part 245 is large, which makes the housing 21 have sufficient creepage distance with other electrical connection parts, so that the insulating part 24 has a better insulation effect, which helps to reduce the risk of short circuit in the housing 21 and improve the reliability of the battery cell 20.

[0212] In some embodiments, the insulating element 24 is an insulating film covering the outer surface of the housing 21.

[0213] When the insulating element 24 is an insulating film, the insulating element 24 can be bonded to the outer surface of the housing 21 to limit the relative position of the insulating element 24 and the housing 21.

[0214] When the insulating component 24 is an insulating film covering the outer surface of the housing 21, the cost of the insulating component 24 itself is low. Furthermore, the process of coating the outer surface of the housing 21 is simple and low-cost, which helps to reduce the cost of the battery cell 20.

[0215] Please refer to Figure 11, which is a cross-sectional view of the insulating member 24 provided in some embodiments of this application. In some embodiments, the insulating film includes a plurality of insulating layers 246 and a plurality of adhesive layers 247. The plurality of insulating layers 246 are stacked, and the insulating layers 246 and adhesive layers 247 are alternately arranged along the stacking direction of the plurality of insulating layers 246.

[0216] The insulating layer 246 has insulating properties and can insulate and isolate the housing 21 from other electrical connection components. The insulating film may include two, three, four, or more insulating layers 246, with multiple insulating layers 246 stacked on top of each other. The material of the insulating layer 246 may be plastic, rubber, etc.

[0217] Along the stacking direction of the insulating layer 246, the insulating layer 246 and the adhesive layer 247 are alternately arranged. The adhesive layer 247 located between two adjacent insulating layers 246 can connect the two adjacent insulating layers 246, and the outermost adhesive layer 247 can be connected to the outer surface of the housing 21 to bond the insulating member 24 to the housing 21.

[0218] By providing multiple insulating layers 246 and multiple adhesive layers 247, the insulating component 24 achieves better insulation performance. Furthermore, it enhances the toughness of the insulating component 24, facilitating its encapsulation.

[0219] In other embodiments, the insulating element 24 is an insulating coating disposed on the outer surface of the housing 21.

[0220] The insulating coating is a coating structure applied to the outer surface of the housing 21. The insulating coating can be one of the following: electrophoretic coating, powder coating, and UV-cured coating.

[0221] The insulating coating is not easily damaged and has better insulation performance, which can effectively insulate the housing 21 and other electrical connection components, thereby reducing the risk of short circuit and improving the reliability of the battery cell 20.

[0222] Referring to Figure 11, in some embodiments, the thickness of the insulating element 24 is H, which satisfies: 0.06mm≤H≤0.15mm.

[0223] H represents the thickness of the insulation component 24. During measurement, multiple measurements can be taken and the average value can be used as H.

[0224] The thickness of the insulating component 24 can be: H = 0.06mm, 0.07mm, 0.08mm, 0.09mm, 0.1mm, 0.11mm, 0.12mm, 0.13mm, 0.14mm, 0.15mm, etc.

[0225] When H ≥ 0.06 mm, the insulation component 24 has a relatively large thickness, resulting in better insulation and reducing the risk of short circuits in the casing 21, thus improving the reliability of the battery cell 20. When H ≤ 0.15 mm, the thickness of the insulation component 24 is not excessive, which helps to reduce the volume of the battery cell 20 and increase its energy density. Therefore, when 0.06 mm ≤ H ≤ 0.15 mm, both the reliability and energy density of the battery cell 20 can be balanced.

[0226] Optionally, 0.09mm ≤ H ≤ 0.13mm.

[0227] The thickness of the insulating component 24 can be: H = 0.09mm, 0.095mm, 0.1mm, 0.105mm, 0.11mm, 0.115mm, 0.12mm, 0.125mm, 0.13mm, etc.

[0228] When H ≥ 0.09 mm, the insulation component 24 is thicker, resulting in better insulation and reducing the risk of short circuits in the casing 21, thus improving the reliability of the battery cell 20. When H ≤ 0.13 mm, the thickness of the insulation component 24 is not excessive, which helps to reduce the volume of the battery cell 20 and increase its energy density. Therefore, when 0.06 mm ≤ H ≤ 0.15 mm, a better balance between the reliability and energy density of the battery cell 20 can be achieved.

[0229] In some embodiments, the pressure relief mechanism 23 is integrally formed with the first wall portion 211.

[0230] "One-piece molding" means that the first wall portion 211 and the pressure relief mechanism 23 are provided as a single structure. For example, the pressure relief mechanism 23 can be formed on the first wall portion 211 by means of stamping or cold forging.

[0231] The pressure relief mechanism 23 is integrally formed with the first wall portion 211, eliminating the need for additional welding or bonding processes, which helps reduce the risk of leakage from the pressure relief mechanism 23. Furthermore, during production, it is easier to ensure that the detonation pressure of multiple battery cells 20 produced is more consistent.

[0232] In other embodiments, the pressure relief mechanism 23 is separately disposed from the first wall portion 211, the first wall portion 211 is provided with a pressure relief hole, and the pressure relief mechanism 23 is installed on the first wall portion 211 and covers the pressure relief hole.

[0233] The phrase "the pressure relief mechanism 23 is separately provided from the first wall portion 211, the first wall portion 211 is provided with a pressure relief hole, and the pressure relief mechanism 23 is installed on the first wall portion 211 and covers the pressure relief hole" means that during manufacturing, a pressure relief hole is provided on the first wall portion 211, and the pressure relief mechanism 23 and the first wall portion 211 are provided separately and ultimately connected together. For example, the pressure relief mechanism 23 can be welded to the first wall portion 211. The pressure relief mechanism 23 can be an explosion-proof plate installed on the first wall portion 211.

[0234] The pressure relief mechanism 23 is separately set and installed on the first wall portion 211 to facilitate processing and manufacturing.

[0235] In some embodiments, the first wall portion 211 is a wall portion of the housing 21 that is disposed opposite to the end cap 22 along the thickness direction of the first wall portion 211.

[0236] The pressure relief mechanism 23 is disposed on the wall of the housing 21 opposite to the end cover 22 along the thickness direction of the first wall 211. The fluid medium ejected by the pressure relief mechanism 23 is less likely to act on other electrical connection structures on the end cover 22, which helps to reduce the risk of short circuit of the battery cell 20.

[0237] This application embodiment also provides a battery device 100, which includes the aforementioned battery cell 20.

[0238] 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.

[0239] This application provides a battery cell 20, which includes a housing 21, an end cap 22, a pressure relief mechanism 23, and an insulating member 24. The housing 21 has an opening and a first wall portion 211. The end cap 22 closes the opening. The pressure relief mechanism 23 is disposed on the first wall portion 211. The pressure relief mechanism 23 includes a first groove 231 and is configured to split along the first groove 231 when the battery cell 20 is depressurized. The insulating member 24 is disposed on the outside of the housing 21 and covers at least a portion of the outer surface of the first wall portion 211. The insulating member 24 is provided with a relief opening 243, and the orthographic projection of the first groove 231 is located within the relief opening 243 along the thickness direction of the first wall portion 211. The pressure relief mechanism 23 is disposed on the first wall portion 211 of the battery cell 20. When the internal pressure of the battery cell 20 reaches the detonation pressure, the pressure relief mechanism 23 can split along the first groove 231 to allow the fluid medium inside the battery cell 20 to flow out and relieve pressure. An insulating member 24 is provided on the outer side of the housing 21. The insulating member 24 can insulate and isolate the housing 21 from other electrical connection components, thereby reducing the risk of short circuit and improving the reliability of the battery cell 20. By providing a clearance opening 243 on the insulating member 24 and placing the orthographic projection of the first groove 231 along the thickness direction of the first wall portion 211 within the clearance opening 243, the clearance opening 243 can avoid the first groove 231. On the one hand, when the battery cell 20 is depressurized, the insulating member 24 is less likely to suppress the deformation of the pressure relief mechanism 23 and the cracking of the first groove 231, allowing the first groove 231 to crack in time when the battery cell 20 is depressurized, which is beneficial to improving the timeliness of pressure relief of the battery cell 20. On the other hand, the presence of the clearance opening 243 makes it less likely for the insulating member 24 to block the fluid medium discharged from the pressure relief mechanism 23. The fluid medium can be directly discharged to the outside of the battery cell 20 through the clearance opening 243, which is beneficial to improving the pressure relief rate and the reliability of the battery cell 20.

[0240] In the projection plane perpendicular to the thickness direction of the first wall portion 211, the minimum distance A between the orthographic projection of the first groove 231 and the orthographic projection of the edge of the clearance opening 243 satisfies: 0.2mm≤A≤5mm. When A≥0.2mm, the minimum distance between the orthographic projection of the first groove 231 and the orthographic projection of the edge of the clearance opening 243 in the projection plane perpendicular to the thickness direction of the first wall portion 211 is relatively large, and the clearance opening 243 has a better clearance effect on the first groove 231. When the battery cell 20 is depressurized, the insulating component 24 is less likely to suppress the deformation of the depressurization mechanism 23, so that the first groove 231 can crack in time when the battery cell 20 is depressurized, which is beneficial to improving the timeliness of depressurization of the battery cell 20. The fluid medium can be directly discharged to the outside of the battery cell 20 through the clearance opening 243, which is beneficial to improving the depressurization rate and the reliability of the battery cell 20. Furthermore, in the projection plane perpendicular to the thickness direction of the first wall portion 211, the minimum distance between the orthographic projection of the first groove 231 and the orthographic projection of the edge of the clearance opening 243 is relatively large, which can absorb assembly errors and lower assembly requirements. When A≤5mm, in the projection plane perpendicular to the thickness direction of the first wall portion 211, the minimum distance between the orthographic projection of the first groove 231 and the orthographic projection of the edge of the clearance opening 243 is not too large, and the clearance opening 243 is not too large, so that the insulating component 24 has a better insulation effect, which is beneficial to improving the reliability of the battery cell 20. Therefore, when 0.2mm≤A≤5mm, the internal pressure of the battery cell 20 can reach the detonation pressure to facilitate the pressure relief mechanism 23 to release pressure, and the insulating component 24 can also have a better insulation effect, so that the battery cell 20 has high reliability.

[0241] The first groove 231 defines a predetermined pressure relief area 233. The pressure relief mechanism 23 includes a second groove 232, the minimum residual thickness of which is greater than the minimum residual thickness of the first groove 231. The second groove 232 is configured to guide at least a portion of the predetermined pressure relief area 233 to flip over, thereby opening at least a portion of the predetermined pressure relief area 233. Along the thickness direction of the first wall portion 211, the orthographic projection of the second groove 232 is located within the clearance opening 243. By providing the second groove 232, the strength of the pressure relief mechanism 23 at the location of the second groove 232 is weakened, making it easier for the predetermined pressure relief area 233 to flip over and open under the action of the fluid medium. This not only increases the probability of opening the predetermined pressure relief area 233 but also increases the opening speed of the predetermined pressure relief area 233, achieving rapid pressure relief, reducing the risk of battery cell 20 explosion and fire, and improving the reliability of the battery cell 20. By providing a clearance opening 243 on the insulating member 24 and placing the orthographic projection of the second groove 232 along the thickness direction of the first wall portion 211 within the clearance opening 243, the clearance opening 243 can avoid the second groove 232. When the battery cell 20 is depressurized, the insulating member 24 is less likely to prevent the predetermined depressurization area 233 from flipping open, so that the predetermined depressurization area 233 can flip open in time when the battery cell 20 is depressurized. This is beneficial to improving the timeliness of depressurization of the battery cell 20 and improving the reliability of the battery.

[0242] The housing 21 includes a plurality of sidewalls 212 surrounding the first wall portion 211. The insulating member 24 includes a plurality of insulating portions 241 and a plurality of flanged portions 242. Each insulating portion 241 covers at least a portion of the outer surface of a sidewall 212. Along the thickness direction of the first wall portion 211, each insulating portion 241 has a flanged portion 242 at one end near the first wall portion 211, and the flanged portion 242 covers a portion of the outer surface of the first wall portion 211. The plurality of flanged portions 242 define a clearance opening 243. By having each insulating portion 241 cover at least a portion of the outer surface of a sidewall 212, the insulation effect of the insulating member 24 is improved. By having a flanged portion 242 at one end of each insulating portion 241 near the first wall portion 211, the flanged portion 242 can cover a portion of the outer surface of the first wall portion 211, thereby reducing the risk of short circuits caused by the first wall portion 211 coming into contact with other electrical connections. Multiple flanges 242 together define the clearance opening 243, which has a simple structure and does not require additional opening steps, thus reducing production processes and production costs.

[0243] The housing 21 includes multiple sidewalls 212 surrounding the first wall portion 211. The insulating member 24 includes a first insulating portion 244 and two second insulating portions 245, which are disposed opposite to each other. The first insulating portion 244 connects the two second insulating portions 245. The first insulating portion 244 covers at least a portion of the outer surface of the first wall portion 211, and each second insulating portion 245 covers at least a portion of the outer surface of one sidewall 212. A clearance opening 243 is a through hole provided in the first insulating portion 244. The insulating member 24, with its first insulating portion 244 covering a portion of the outer surface of the first wall portion 211 and each second insulating portion 245 covering at least a portion of the outer surface of one sidewall 212, has a simple structure, facilitating its placement on the outside of the housing 21. The clearance opening 243 is a through hole provided in the first insulating part 244, which makes it easier for the size of the clearance opening 243 to be adapted to the size of the pressure relief mechanism 23, so that the size of the clearance opening 243 is moderate, which can not only properly avoid the pressure relief mechanism 23, but also enable the insulating part 24 to have a good insulation effect.

[0244] 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, wherein, include: A housing having an opening, the housing having a first wall portion; End cap, to close the opening; A pressure relief mechanism is disposed on the first wall portion, the pressure relief mechanism includes a first groove, and the pressure relief mechanism is configured to split along the first groove when the battery cell is depressurized; An insulating element is disposed on the outside of the housing and covers at least a portion of the outer surface of the first wall portion; The insulating component is provided with a clearance opening, and along the thickness direction of the first wall portion, the orthographic projection of the first groove is located within the clearance opening.

2. The battery cell according to claim 1, wherein, In the projection plane perpendicular to the thickness direction of the first wall portion, the minimum distance between the orthographic projection of the first groove and the orthographic projection of the edge of the clearance opening is A, which satisfies: 0.2mm≤A≤5mm.

3. The battery cell according to claim 1 or 2, wherein, The first groove defines a predetermined pressure relief area, and the pressure relief mechanism includes a second groove having a minimum residual thickness greater than that of the first groove. The second groove is configured to guide at least a portion of the predetermined pressure relief area to flip over to open at least a portion of the predetermined pressure relief area.

4. The battery cell according to claim 3, wherein, Along the thickness direction of the first wall portion, the orthographic projection of the second groove lies within the clearance opening.

5. The battery cell according to claim 4, wherein, Along the width direction of the second groove, the edge of the clearance opening has a first edge that is opposite to and closest to the second groove. In the projection plane perpendicular to the thickness direction of the first wall, the minimum distance between the orthographic projection of the second groove and the orthographic projection of the first edge along the width direction of the second groove is B, which satisfies: 0 < B ≤ 10 mm.

6. The battery cell according to claim 3, wherein, The insulating element covers the second groove.

7. The battery cell according to claim 6, wherein, Along the width direction of the second groove, the edge of the clearance opening has a first edge that is opposite to and closest to the second groove. In the projection plane perpendicular to the thickness direction of the first wall, the minimum distance between the orthographic projection of the second groove and the orthographic projection of the first edge along the width direction of the second groove is B, which satisfies: 0≤B≤3mm.

8. The battery cell according to any one of claims 3-7, wherein, The first groove includes a first groove segment, a second groove segment, and a third groove segment. The second groove and the second groove segment are arranged opposite to each other along a first direction. The first groove segment and the third groove segment are arranged opposite to each other along a second direction. The second groove segment connects the first groove segment and the third groove segment. The first groove segment, the second groove segment, and the third groove segment together define at least one of the predetermined pressure relief zones. The first direction, the second direction, and the thickness direction of the first wall are perpendicular to each other.

9. The battery cell according to any one of claims 1-8, wherein, The housing includes a plurality of sidewalls, which surround the first wall portion; The insulating member includes a plurality of insulating portions and a plurality of flanged portions. Each insulating portion covers at least a portion of the outer surface of one of the sidewalls. Along the thickness direction of the first wall portion, each insulating portion is provided with a flanged portion at one end near the first wall portion. The flanged portion covers a portion of the outer surface of the first wall portion. The plurality of flanged portions define the clearance opening.

10. The battery cell according to claim 9, wherein, The width of the flange is L, which satisfies: L≥2mm.

11. The battery cell according to any one of claims 1-8, wherein, The housing includes a plurality of sidewalls, which surround the first wall portion; The insulating component includes a first insulating portion and two second insulating portions. The two second insulating portions are disposed opposite each other along a first direction. The first insulating portion connects the two second insulating portions. The first insulating portion covers at least a portion of the outer surface of the first wall portion. Each second insulating portion covers at least a portion of the outer surface of one of the sidewalls. The clearance opening is a through hole provided in the first insulating portion. The first direction is perpendicular to the thickness direction of the first wall portion.

12. The battery cell according to claim 11, wherein, The plurality of sidewalls include two second wall portions disposed opposite to each other along the first direction and two third wall portions disposed opposite to each other along the second direction, wherein the first direction, the second direction and the thickness direction of the first wall portion are perpendicular to each other; Each of the second insulating portions covers at least a portion of the outer surface of one of the second wall portions; The insulating member includes a flanged portion, and at least one end of the second insulating portion and the first insulating portion is provided with the flanged portion along the second direction, the flanged portion covering a portion of the outer surface of the third wall portion.

13. The battery cell according to claim 11 or 12, wherein, Along the thickness direction of the second insulating part, the minimum distance between the edge of the clearance opening and the outer surface of the second insulating part is C, which satisfies: C≥2mm.

14. The battery cell according to any one of claims 1-13, wherein, The insulating component is an insulating film covering the outer surface of the housing.

15. The battery cell according to claim 14, wherein, The insulating film includes multiple insulating layers and multiple adhesive layers, with the multiple insulating layers stacked on top of each other and the insulating layers and adhesive layers alternately arranged along the stacking direction of the multiple insulating layers.

16. The battery cell according to any one of claims 1-13, wherein, The insulating element is an insulating coating disposed on the outer surface of the housing.

17. The battery cell according to any one of claims 1-16, wherein, The thickness of the insulating component is H, which satisfies the following condition: 0.06mm ≤ H ≤ 0.15mm.

18. The battery cell according to claim 17, wherein, 0.09mm≤H≤0.13mm.

19. The battery cell according to any one of claims 1-18, wherein, The pressure relief mechanism is integrally formed with the first wall portion.

20. The battery cell according to any one of claims 1-18, wherein, The pressure relief mechanism is separately disposed from the first wall portion, the first wall portion is provided with a pressure relief hole, and the pressure relief mechanism is installed on the first wall portion and covers the pressure relief hole.

21. The battery cell according to any one of claims 1-20, wherein, The first wall portion is a wall portion of the housing that is disposed opposite to the end cap along the thickness direction of the first wall portion.

22. A battery device, wherein, Includes the battery cell according to any one of claims 1-21.

23. An electrical appliance, wherein, Includes a battery cell according to any one of claims 1-21, the battery cell being used to provide electrical energy to the electrical device.

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