Battery cell, battery device and electric apparatus

Abstract

The embodiments of the present application belong to the technical field of batteries. Disclosed are a battery cell, a battery device and an electric apparatus. The battery cell comprises: a casing, which comprises a first wall; an electrode assembly, which is accommodated in the casing; and an insulating plate, which is arranged between the electrode assembly and the first wall and comprises a middle portion and ends, wherein in the direction of length of the first wall, the ends are located on two sides of the middle portion, and the thickness of the middle portion is greater than the thickness of the ends, such that the reliability of the battery cell can be improved.

Description

Battery cells, battery devices and electrical equipment Technical Field

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

[0002] With increasing environmental pollution, the new energy industry is attracting more and more attention. Within the new energy industry, battery technology is a crucial factor in its development.

[0003] The development of battery technology requires consideration of various design factors, such as energy density, cycle life, and reliability. How to provide a highly reliable battery cell is a pressing technical problem that needs to be solved.

[0004] Summary of the Invention

[0005] This application provides a battery cell, a battery device, and an electrical appliance, which can improve the reliability of the battery cell.

[0006] In a first aspect, a battery cell is provided, comprising: a housing including a first wall; an electrode assembly housed within the housing; and an insulating plate disposed between the electrode assembly and the first wall, the insulating plate including a middle portion and end portions, the end portions being located on both sides of the middle portion along the length direction of the first wall, the thickness of the middle portion being greater than the thickness of the end portions.

[0007] In this embodiment, the battery cell includes a casing, an electrode assembly, and an insulating plate. The electrode assembly is housed within the casing, and the insulating plate is disposed between the electrode assembly and the first wall of the casing. The insulating plate isolates the electrode assembly from the casing and provides some support for the electrode assembly. The thickness of the middle portion of the insulating plate is greater than that of the ends, which increases the strength of the middle portion and reduces its deformation. This reduces the risk of the ends damaging the electrode assembly due to excessive deformation of the middle portion, thus improving the reliability of the battery cell.

[0008] In some embodiments, along the thickness direction of the first wall, the intermediate portion includes a first intermediate surface facing the first wall, and the end portion includes a first end surface facing the first wall. The first intermediate surface is closer to the first wall than the first end surface, and the gap between the first intermediate surface and the first wall is smaller than the gap between the first end surface and the first wall. This reduces the maximum deformation of the intermediate portion, further reducing the risk of the end portion damaging the electrode assembly due to excessive deformation of the intermediate portion, thus improving the reliability of the battery cell.

[0009] In some embodiments, the gap D between the first intermediate surface and the first wall satisfies: 0 ≤ D ≤ 0.5 mm. This smaller gap between the first intermediate surface and the outer casing reduces the shaking of the electrode assembly within the casing and the maximum deformation of the intermediate portion, thus reducing the risk of the electrode assembly being damaged by excessive deformation of the intermediate portion at the ends, and improving the reliability of the battery cell.

[0010] In some embodiments, the housing includes a first wall and a second wall, the second wall being adjacent to the first wall and having electrode terminals disposed thereon; the electrode assembly includes a main body and tabs extending from the main body; the battery cell further includes an isolation member, the isolation member being at least partially disposed between the main body and the second wall, and at least a portion of the end portion being connected to the isolation member.

[0011] In the above embodiments, the isolation member is at least partially disposed between the main body of the electrode assembly and the second wall provided with the electrode terminals, thereby isolating at least a portion of the tab from the main body and reducing the risk of short circuit caused by inserting the tab into the main body; in addition, at least a portion of the end of the insulating plate is connected to the isolation member, thereby facilitating the connection of the electrode assembly, the isolation member and the insulating plate into a whole and reducing the shaking of the electrode assembly in the housing.

[0012] In some embodiments, the thickness H1 of the middle portion satisfies: 0.2mm≤H1≤7mm; and / or, the thickness H2 of the end portion satisfies: 0.1mm≤H2≤2mm.

[0013] When H1 is greater than or equal to 0.2 mm, it helps to reduce or fill the gap between the middle part of the insulating plate and the outer casing, thereby reducing the risk of the electrode assembly shaking within the casing and being squeezed by the ends of the insulating plate. When H1 is less than or equal to 7 mm, it helps to reduce the space occupied by the insulating plate and increase the energy density of the battery cell. When H2 is greater than or equal to 0.1 mm, the ends of the insulating plate have suitable strength, which can reduce the risk of end breakage. When H2 is less than or equal to 2 mm, it helps to reduce the space occupied by the insulating plate and increase the energy density of the battery cell.

[0014] In some embodiments, 0.4mm ≤ H1 ≤ 5mm; and / or, 0.3mm ≤ H2 ≤ 0.5mm.

[0015] When 0.4 mm ≤ H1 ≤ 5 mm, H1 has a relatively appropriate size, which can not only reduce or even fill the gap between the middle part of the insulating plate and the housing, reducing the risk of the electrode assembly shaking in the housing and being squeezed by the end of the insulating plate, but also be conducive to improving the energy density of the battery cell. When 0.3 mm ≤ H2 ≤ 0.5 mm, H2 has an appropriate size, which is conducive to both enhancing the strength of the end of the insulating plate and improving the energy density of the battery cell.

[0016] In some embodiments, the length L1 of the middle part satisfies: 1 mm ≤ L1 < L0, and / or, the length L2 of the end part satisfies: 5 mm ≤ L2 ≤ 0.5L0, where L0 is the length of the main body part of the electrode assembly, and the electrode assembly includes the main body part and the ear extending from the main body part.

[0017] By setting L1 to be greater than or equal to 1 mm, the middle part has a certain length, which can thus play a certain supporting role for the electrode assembly, reducing the risk of the electrode assembly shaking and being squeezed. By setting L1 to be less than L0, it is convenient to install the insulating plate into the housing, reducing the risk of interference between the insulating plate and the housing during the assembly of the battery cell. By setting L2 to be greater than or equal to 5 mm, it is convenient for the connection between the end part and the isolation member. By setting L2 to be less than or equal to 0.5L0, the end part has an appropriate length, so that the middle part also has a relatively appropriate length, the insulating plate has a relatively appropriate strength and has a good supporting effect on the electrode assembly, which is conducive to enhancing the reliability of the battery cell.

[0018] In some embodiments, 10 mm ≤ L1 ≤ 250 mm; and / or, 5 mm ≤ L2 ≤ 100 mm.

[0019] When L1 is greater than or equal to 10 mm, the middle part can play a certain supporting role for the electrode assembly, reducing the risk of the electrode assembly shaking and being squeezed; when L1 is less than or equal to 250 mm, the length of the insulating plate can be adapted to the length of the main body part of the electrode assembly, facilitating the assembly and preparation of the battery cell. When L2 is greater than or equal to 5 mm, it is convenient for the connection between the end part and the isolation member; when L2 is less than or equal to 100 mm, the insulating plate has a relatively appropriate strength and the middle part also has a relatively appropriate length, which is conducive to enhancing the reliability of the battery cell.

[0020] In some embodiments, 50 mm ≤ L1 ≤ 200 mm; and / or, 10 mm ≤ L2 < 30 mm.

[0021] When L1 ≤ 200 mm, the middle section has a suitable length, which can match the length of the electrode assembly and reduce the risk of electrode assembly shaking and being squeezed. When L2 < 30 mm, the end section has a suitable length, which facilitates the connection of the insulating plate and the isolation component, and makes it easier to obtain an end section with a suitable length and an insulating plate with a suitable strength, thereby improving the reliability of the battery cell.

[0022] In some embodiments, the insulating plate further includes a transition portion connecting the intermediate portion and the end portion; along the length direction of the first wall, the transition portion includes a first end and a second end, the first end being connected to the intermediate portion and the second end being connected to the end portion, and the thickness of the transition portion at the first end being greater than the thickness of the transition portion at the second end.

[0023] By setting a transition section, it is easier to insert the insulating plate into the outer casing during the assembly of the battery cell, reducing the risk of interference between the insulating plate and the outer casing.

[0024] In some embodiments, the transition portion includes a first transition surface and a second transition surface opposite to each other along the thickness direction of the first wall, the second transition surface protruding from the end portion. The arrangement of the first and second transition surfaces facilitates variations in the thickness of the transition portion.

[0025] In some embodiments, the connection between the second transition surface and the end portion, and / or the connection between the second transition surface and the middle portion, is provided with an arc-shaped structure. This makes the connections between the transition portion and the end portion, and between the transition portion and the middle portion, smoother, which helps reduce the risk of interference between the connections between the transition portion and the end portion, and between the transition portion and the middle portion, and the housing or electrode assembly.

[0026] In some embodiments, the second transition surface faces the electrode assembly, and the first transition surface faces the first wall. This makes the connections between the transition portion and the end portion, as well as between the transition portion and the middle portion, smoother, which helps reduce the risk of the second transition surface damaging the electrode assembly, thereby improving the reliability of the battery cell.

[0027] In some embodiments, a first groove is provided on the insulating plate at the corner corresponding to the electrode assembly, and the first groove is recessed in a direction away from the electrode assembly. The first groove corresponds to the corner of the electrode assembly, thereby forming a space to avoid the corner of the electrode assembly, reducing the risk of the insulating plate damaging the electrode assembly, and improving the reliability of the battery cell.

[0028] In some embodiments, the transition portion includes a first transition surface and a second transition surface that are opposite to each other in the thickness direction of the first wall. The second transition surface protrudes from the end portion, and the second transition surface faces the first wall. The end portion includes a first end surface and a second end surface that are opposite to each other in the thickness direction of the first wall, and the first end surface faces the first wall. The first groove is provided on the first transition surface, or the first groove is provided on the second end surface, or the first groove is provided at the connection between the first transition surface and the second end surface. By providing the first groove, the risk of the transition portion damaging the electrode assembly can be reduced, which is beneficial to improving the reliability of the battery cell.

[0029] In some embodiments, the relationship between the depth H3 of the first groove, the thickness H1 of the middle portion, and the thickness H2 of the end portion satisfies: 0.3H2 ≤ H3 < H2.

[0030] When H3 is greater than or equal to 0.2H2, the edges and corners of the electrode assembly can be avoided, and the risk of the insulating plate damaging the electrode assembly can be reduced; when H3 is less than H2, the insulating plate has a more appropriate strength at the first groove, and the risk of the insulating plate breaking at the first groove can be reduced.

[0031] In some embodiments, 0.2 mm ≤ H3 < 2 mm.

[0032] When H3 is greater than or equal to 0.2 mm, the edges and corners of the electrode assembly can be avoided, and the risk of the insulating plate damaging the electrode assembly can be reduced; when H3 is less than or equal to 2 mm, the insulating plate has a more appropriate strength at the first groove, and the risk of the insulating plate breaking at the first groove can be reduced.

[0033] In some embodiments, 0.3 mm ≤ H3 ≤ 0.5 mm. In this way, the first groove has an appropriate depth, which is beneficial to avoiding the edges and corners of the electrode assembly and reducing the risk of the electrode assembly being damaged, and the insulating plate also has a more appropriate strength.

[0034] In some embodiments, along the length direction of the first wall, the size L3 of the first groove satisfies: 1 mm ≤ L3 ≤ 20 mm.

[0035] When L3 is greater than or equal to 1 mm, the edges and corners of the electrode assembly can be avoided, and the risk of the insulating plate damaging the electrode assembly can be reduced; when L3 is less than or equal to 20 mm, the insulating plate has a more appropriate strength at the first groove, and the risk of the insulating plate breaking at the first groove can be reduced.

[0036] In some embodiments, 3mm ≤ L3 ≤ 15mm. In this way, the first groove has a suitable length, which helps to avoid the sharp edges of the electrode assembly, reducing the risk of the electrode assembly being crushed, while the insulating plate also has a suitable strength.

[0037] In some embodiments, the length L5 of the transition portion satisfies: 0 <L5≤60mm。

[0038] When L5 is greater than 0, the transition section has a certain length, which facilitates the insertion of the insulating plate into the housing; when L5 is less than or equal to 60mm, the transition section has a suitable length, so that the middle and end sections can also have suitable lengths, and the insulating plate provides good support for the electrode assembly and has suitable strength.

[0039] In some embodiments, 2mm ≤ L5 ≤ 20mm. This provides a suitable length for the transition portion, facilitating the insertion of the insulating plate into the housing and resulting in an insulating plate that provides good support for the electrode assembly and has appropriate strength.

[0040] In some embodiments, along the thickness direction of the first wall, at least one second groove is provided on the side of the insulating plate facing the outer casing. This facilitates the formation of an exhaust channel on the insulating plate, enabling the discharge of high-temperature, high-pressure substances inside the battery cell in the event of thermal runaway.

[0041] In some embodiments, the insulating plate has a plurality of second grooves on the side facing the outer casing, and the plurality of second grooves are spaced apart along the length of the first wall. By providing a plurality of second grooves, it is beneficial to form a plurality of exhaust channels, which is beneficial to the discharge of high-temperature and high-pressure substances inside the battery cell in the event of thermal runaway of the battery cell.

[0042] In some embodiments, the total projected area S1 of the at least one second groove on the first plane and the projected area S0 of the insulating plate on the first plane satisfy: 0.05S0≤S1≤0.5S0; the first plane is parallel to the length direction and thickness direction of the insulating plate.

[0043] When S1 is greater than or equal to 0.05S0, the exhaust channel formed by the second groove has a suitable exhaust area, which facilitates the smooth discharge of high-temperature and high-pressure substances inside the battery cell when the battery cell experiences thermal runaway; when S1 is less than or equal to 0.5S0, the insulating plate has suitable strength and provides suitable support for the electrode assembly, which can reduce the risk of the electrode assembly being crushed and shaking inside the casing.

[0044] In some embodiments, the depth H4 of the second groove satisfies: 0.2mm≤H4≤5mm, and / or, along the length direction of the first wall, the size L4 of the second groove satisfies: 1mm≤L4≤20mm.

[0045] When H4 is greater than or equal to 0.2 mm, the second groove has a suitable depth to facilitate the passage of gases and other emissions from the battery cell; when H4 is less than or equal to 5 mm, the middle portion has suitable strength to provide good support for the electrode assembly, reducing the risk of the electrode assembly being crushed or moving within the casing. When L4 is greater than or equal to 1 mm, the second groove has a suitable length to facilitate the passage of gases and other emissions from the battery cell; when L4 is less than or equal to 20 mm, the middle portion has suitable strength to provide good support for the electrode assembly, reducing the risk of the electrode assembly being crushed or moving within the casing.

[0046] In some embodiments, 0.2mm ≤ H4 ≤ 5mm, and / or 3mm ≤ L4 ≤ 15mm.

[0047] When the diameter is 0.2mm ≤ H4 ≤ 5mm, it facilitates the passage of gases and other emissions within the battery cell while reducing the risk of damage to the electrode assembly and movement within the casing. When the diameter is 3mm ≤ L4 ≤ 15mm, it facilitates the passage of gases and other emissions within the battery cell while reducing the risk of damage to the electrode assembly and movement within the casing.

[0048] In some embodiments, the materials of the insulating member and the insulating plate include thermoplastic insulating materials. Thus, during the fabrication of the battery cell, the insulating member and the insulating plate can be connected by heating them.

[0049] In some embodiments, the battery cell includes two second walls and two first walls, wherein the second walls and the first walls are perpendicular.

[0050] In some embodiments, the battery cell includes an insulating film that is sleeved on the outer surface of the electrode assembly and has an inner side of the housing; an insulating plate is at least partially disposed between the insulating film and the electrode assembly. Thus, the insulating film, electrode assembly, and insulating plate are connected to form a single unit, facilitating the assembly of the battery cell.

[0051] In some embodiments, the electrode assembly includes alternately stacked first and second electrodes, one of which is a positive electrode and the other a negative electrode. Thus, the battery cell including this electrode assembly is a stacked battery cell, which has a high energy density.

[0052] In a second aspect, a battery device is provided, which is the battery cell described in the first aspect or any embodiment of the first aspect.

[0053] Thirdly, an electrical device is provided, comprising: a battery cell as described in the first aspect or any embodiment of the first aspect, or a battery device as described in the second aspect, wherein the battery cell or the battery device is used to store or provide electrical energy.

[0054] In this embodiment, the battery cell includes a casing, an electrode assembly, and an insulating plate. The electrode assembly is housed within the casing, and the insulating plate is disposed between the electrode assembly and the first wall of the casing. The insulating plate isolates the electrode assembly from the casing and provides some support for the electrode assembly. The thickness of the middle portion of the insulating plate is greater than that of the ends, which increases the strength of the middle portion, reduces its deformation, and thus reduces the risk of the ends damaging the electrode assembly due to excessive deformation of the middle portion. Attached Figure Description

[0055] Figure 1 is a structural schematic diagram of a vehicle according to an embodiment of this application;

[0056] Figure 2 is a schematic diagram of the structure of a battery device according to an embodiment of this application;

[0057] Figure 3 is a schematic diagram of the structure of a battery cell according to an embodiment of this application;

[0058] Figure 4 is a schematic diagram of the exploded structure of a battery cell according to an embodiment of this application;

[0059] Figure 5 is a structural schematic diagram of a battery cell according to an embodiment of this application from another perspective;

[0060] Figure 6 is a cross-sectional view of the battery cell in Figure 5 along the AA direction;

[0061] Figure 7 is a schematic diagram of the structure of an insulating plate according to an embodiment of this application;

[0062] Figure 8 is an enlarged schematic diagram of region B in Figure 6;

[0063] Figure 9 is a schematic diagram of the deformed insulating plate and electrode assembly in the related technology;

[0064] Figure 10 is a structural schematic diagram of an isolation member according to an embodiment of this application;

[0065] Figure 11 is a schematic diagram of the structure of a battery cell according to an embodiment of this application;

[0066] Figure 12 is a schematic diagram of the structure of an insulating plate according to an embodiment of this application;

[0067] Figure 13 is an enlarged schematic diagram of region C of the battery cell in Figure 11;

[0068] Figure 14 is a schematic diagram of the structure of a battery cell according to an embodiment of this application;

[0069] Figure 15 is a schematic diagram of the structure of an insulating plate according to an embodiment of this application;

[0070] Figure 16 is an enlarged schematic diagram of region D in Figure 14;

[0071] Figure 17 is a schematic diagram of the structure of an insulating plate according to an embodiment of this application;

[0072] The accompanying drawings are not drawn to scale.

[0073] Reference numerals: 1: Vehicle; 10: Battery device; 30: Controller; 40: Motor; 11: Housing; 111: First housing section; 112: Second housing section; 20: Battery cell; 21: Housing; 22: Electrode assembly; 221: Main body section; 222: Tab; 22a: Edge; 23: Isolation member; 2330: Channel; 601: Slot structure; 24: Second wall; 240: Electrode terminal; 211: Housing; 212: End cap; 25: First wall; 26: Insulating film; 27: Insulating plate; 271: Middle section; 272: End; 273: Transition section; 2711: First intermediate surface; 2712: Second intermediate surface; 2721: First end surface; 2722: Second end surface; 2731: First transition surface; 2732: Second transition surface; 281: First groove; 282: Second groove. Detailed Implementation

[0074] The technical solutions in the embodiments of this application will now be described with reference to the accompanying drawings.

[0075] 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.

[0076] 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.

[0077] In this application, the reference to "embodiment" means that a specific 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 throughout the specification does not necessarily refer to the same embodiment, nor is it a mutually exclusive, independent, or alternative embodiment. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described in this application can be combined with other embodiments.

[0078] 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.

[0079] 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.

[0080] 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.

[0081] In this application, "multiple" refers to two or more (including two), and similarly, "multiple groups" refers to two or more (including two), and "multiple pieces" refers to two or more (including two).

[0082] Unless otherwise specified, all embodiments and optional embodiments of this application can be combined to form new technical solutions.

[0083] Unless otherwise specified, all technical features and optional technical features of this application may be combined to form new technical solutions.

[0084] Unless otherwise specified, all steps of this application may be performed sequentially or randomly, preferably sequentially. For example, the method includes steps (a) and (b), indicating that the method may include steps (a) and (b) performed sequentially, or it may include steps (b) and (a) performed sequentially. For example, the mention that the method may also include step (c) indicates that step (c) may be added to the method in any order; for example, the method may include steps (a), (b), and (c), or it may include steps (a), (c), and (b), or it may include steps (c), (a), and (b), etc.

[0085] 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.

[0086] The battery cell can be a lithium-ion battery, sodium-ion battery, sodium-lithium-ion battery, lithium metal battery, sodium metal battery, lithium-sulfur battery, magnesium-ion battery, nickel-metal hydride battery, nickel-cadmium battery, lead-acid battery, etc., and the embodiments of this application are not limited to this.

[0087] A single battery cell typically includes an electrode assembly. The electrode assembly includes a positive electrode, a negative electrode, and a separator, with the separator positioned between the positive and negative electrodes. 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, prevents short circuits while allowing active ions to pass through.

[0088] 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.

[0089] 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.

[0090] As an example, the positive current collector can be a metal foil, a conductive polymer material, a carbon material, or a composite current collector. For example, as a metal foil, pure metals, alloys, or surface-treated metals can be used, including but not limited to stainless steel, copper, aluminum, nickel, titanium, or silver. The composite current collector may include a polymer material base layer and a metal layer. The composite current collector can be formed by forming a metal material (aluminum, aluminum alloys, nickel, nickel alloys, titanium, titanium alloys, silver, and silver alloys, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0091] 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 battery positive electrode active materials 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) 0.8 Co 0.15 Al 0.05At least one of O2 and its modified compounds. Modified compounds refer to substances obtained by modification methods such as doping or coating based on the above-mentioned substances.

[0092] In some embodiments, the positive electrode can be a foamed metal. The foamed metal can be foamed nickel, foamed copper, foamed aluminum, foamed alloy, or foamed carbon, 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, a positive electrode active material is filled and / or deposited within the foamed metal.

[0093] In some embodiments, the negative electrode may be a negative electrode sheet, and the negative electrode sheet may include a negative electrode current collector.

[0094] As an example, the negative electrode current collector can be a metal foil, a conductive polymer material, a carbon material, or a composite current collector. For example, as a metal foil, pure metals, alloys, or surface-treated metals can be used, including but not limited to stainless steel, copper, aluminum, nickel, titanium, or silver. The composite current collector may include a polymer material substrate and a metal layer. The composite current collector can be formed by forming a metal material (copper, copper alloys, nickel, nickel alloys, titanium, titanium alloys, silver, and silver alloys, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0095] 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.

[0096] 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.

[0097] 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 for battery cells may also be used. These negative electrode active materials may be used alone or in combination of two or more.

[0098] In some embodiments, the negative electrode can be a foamed metal. The foamed metal can be foamed nickel, foamed copper, foamed aluminum, foamed alloy, or foamed carbon, etc. When foamed metal is used as the negative electrode sheet, the surface of the foamed metal may or may not have a negative electrode active material.

[0099] As an example, negative electrode active materials can be filled or / and deposited within the negative electrode current collector.

[0100] In some embodiments, the positive current collector can be made of aluminum, and the negative current collector can be made of copper.

[0101] In some embodiments, the electrode assembly further includes an isolator disposed between the positive and negative electrodes.

[0102] In some embodiments, the separator is a separator membrane. This application does not impose any particular limitation on the type of separator membrane; any known porous separator membrane with good chemical and mechanical stability can be selected.

[0103] As an example, the main material of the separator can be selected from at least one of glass fiber, non-woven fabric, polyethylene, polypropylene, polyvinylidene fluoride, and ceramic. The separator can be a single-layer film or a multi-layer composite film, without particular limitation. When the separator is a multi-layer composite film, the materials of each layer can be the same or different, without particular limitation. The separator can be a single component located between the positive and negative electrodes, or it can be attached to the surfaces of the positive and negative electrodes. An inorganic particle coating, an organic particle coating, or an organic / inorganic composite coating can also be applied to the surface of the separator.

[0104] 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.

[0105] In some embodiments, the battery cell further includes an electrolyte, which acts as a conductor of ions between the positive and negative electrodes. This application does not impose specific limitations on the type of electrolyte; it can be selected according to requirements. The electrolyte can be liquid, gel, or solid.

[0106] Liquid electrolytes include electrolyte salts and solvents.

[0107] In some embodiments, the electrolyte salt may be selected from 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.

[0108] In some embodiments, the solvent may be selected from at least one of 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 of ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, 1,3-dioxolane, tetrahydrofuran, methyl tetrahydrofuran, diphenyl ether, and crown ethers.

[0109] In some embodiments, the electrolyte may optionally include additives. For example, additives may include negative electrode film-forming additives, positive electrode film-forming additives, and additives that can improve certain properties of the battery cell, such as additives that improve the overcharge / fast charge performance of the battery cell, additives that improve the high-temperature performance of the battery cell, and additives that improve the low-temperature performance of the battery cell.

[0110] The gel electrolyte includes a polymer as a backbone network and can be used in conjunction with an ionic liquid-lithium salt.

[0111] Solid electrolytes include polymer solid electrolytes, inorganic solid electrolytes, and composite solid electrolytes.

[0112] As an example, the polymers of polymeric solid electrolytes may include polyethers (polyoxyethylene), polysiloxanes, polycarbonates, polyacrylonitrile, polyvinylidene fluoride, polymethyl methacrylate, monoionic polymers, polyionic liquids, cellulose, etc.

[0113] As an example, inorganic solid electrolytes can be 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-phosphorus-sulfur, sulfosilium-germanium), amorphous sulfides), halide solid electrolytes, nitride solid electrolytes, and hydride solid electrolytes.

[0114] As an example, composite solid electrolytes are formed by adding inorganic solid electrolyte fillers to polymer solid electrolytes.

[0115] The technical solutions described in the embodiments of this application are applicable to various electrical devices that use individual battery cells, such as mobile phones, portable devices, laptops, electric vehicles, electric toys, power tools, vehicles, ships, and spacecraft. For example, spacecraft include airplanes, rockets, space shuttles, and spacecraft.

[0116] Currently, judging from market trends, the application of power batteries is becoming increasingly widespread. Power batteries are not only used in energy storage systems such as hydropower, thermal power, wind power, and solar power plants, but also extensively used 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 power 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, charge / discharge rate, and reliability. Among these, the structure of the battery cell is crucial to its performance. A battery cell consists of a casing, electrode components, and an insulating plate. The insulating plate is positioned between the electrode components and the casing to support the electrode components, thereby constraining and fixing them to a certain extent.

[0118] In battery cells, a certain gap is usually left to facilitate the insertion of electrode components and insulating plates into the casing during battery cell assembly. However, due to the existence of the gap, there is a risk of the electrode components moving around inside the casing; and the insulating plate may bend or deform under the weight of the electrode components. The deformed insulating plate will severely compress the electrode components, and there is a risk of crushing the edges of the electrode components, which is detrimental to the reliability of the battery cell.

[0119] In view of this, embodiments of this application provide a battery cell, which includes a casing, an electrode assembly, and an insulating plate. The electrode assembly is housed within the casing, and the insulating plate is disposed between the electrode assembly and a first wall of the casing. The insulating plate includes a middle portion and end portions. Along the length direction of the first wall, the end portions are located on both sides of the middle portion, and the thickness of the middle portion is greater than the thickness of the end portions. This increases the strength of the middle portion and reduces its deformation, thereby reducing the risk of the end portions damaging the electrode assembly due to excessive deformation of the middle portion.

[0120] The technical solutions described in the embodiments of this application are applicable to various electrical devices that use battery devices.

[0121] Electrical equipment can include vehicles, mobile phones, portable devices, laptops, ships, spacecraft, electric toys, and power tools, etc. Vehicles can be gasoline-powered cars, natural gas-powered cars, or new energy vehicles; new energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles, etc. Spacecraft include airplanes, rockets, space shuttles, and spacecraft, etc. Electric toys include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc. Power tools include metal cutting power tools, grinding power tools, assembly power tools, and railway power tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, and electric planers, etc. This application does not impose any special limitations on the above-mentioned electrical equipment.

[0122] For ease of explanation, the following embodiments use a vehicle as an example of electrical equipment.

[0123] Figure 1 is a schematic diagram of the structure of a vehicle according to an embodiment of this application. For example, as shown in Figure 1, vehicle 1 can be a gasoline vehicle, a natural gas vehicle, or a new energy vehicle. New energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles, etc. A motor 40, a controller 30, and a battery device 10 can be installed inside vehicle 1. The controller 30 is used to control the battery device 10 to supply power to the motor 40. For example, the battery device 10 can be installed at the bottom, front, or rear of vehicle 1. The battery device 10 can be used to supply power to vehicle 1. For example, the battery device 10 can serve as the operating power source for vehicle 1, for example, for the electrical system of vehicle 1, such as for the power requirements of vehicle 1's starting, navigation, and operation. In another embodiment of this application, the battery device 10 can not only serve as the operating power source for vehicle 1, but also as the driving power source for vehicle 1, replacing or partially replacing gasoline or natural gas to provide driving power to vehicle 1.

[0124] Figure 2 is a schematic diagram of the structure of a battery device according to an embodiment of this application. For example, as shown in Figure 2, the battery device 10 of this application embodiment may include multiple battery cells 20 to meet different power usage requirements. The shape of the battery cell 20 in this application embodiment can be set according to actual applications. For example, the battery cell 20 can be a cuboid shape as shown in Figure 2, or it can be a cylindrical shape or other shapes different from those shown in Figure 2. This application embodiment is not limited to these.

[0125] It should be understood that, as shown in FIG. 2, the battery device 10 of this embodiment may further include a housing 11, which can be used to accommodate multiple battery cells 20. The housing 11 of this embodiment has a hollow internal structure, and the multiple battery cells 20 are accommodated within the housing 11. The housing 11 may include two parts, referred to herein as a first housing portion 111 and a second housing portion 112, which are fastened together. The shapes of the first housing portion 111 and the second housing portion 112 can be determined according to the shape of the components housed inside, for example, according to the shape of the combination of the multiple battery cells 20 housed inside. At least one of the first housing portion 111 and the second housing portion 112 has an opening. For example, as shown in Figure 2, the first housing portion 111 and the second housing portion 112 can both be hollow cuboids with one open side each. The openings of the first housing portion 111 and the second housing portion 112 are opposite to each other, and the first housing portion 111 and the second housing portion 112 are interlocked to form a housing 11 with a closed cavity, which can be used to accommodate multiple battery cells 20. The multiple battery cells 20 are connected in parallel, series, or mixed and placed inside the housing 11 formed by the interlocking of the first housing portion 111 and the second housing portion 112.

[0126] For example, unlike what is shown in Figure 2, only one of the first housing portion 111 and the second housing portion 112 may be a hollow cuboid with an opening, while the other is plate-shaped to cover the opening. Taking the second housing portion 112 as a hollow cuboid with one opening, and the first housing portion 111 as a plate-shaped example, then the first housing portion 111 covers the opening of the second housing portion 112 to form a housing 11 with a closed chamber, which can be used to accommodate multiple battery cells 20.

[0127] Figure 3 is a structural schematic diagram of a battery cell according to an embodiment of this application; Figure 4 is an exploded structural schematic diagram of a battery cell according to an embodiment of this application; Figure 5 is a structural schematic diagram of a battery cell according to another perspective according to an embodiment of this application; Figure 6 is a cross-sectional view of the battery cell in Figure 5 along the AA direction; Figure 7 is a structural schematic diagram of an insulating plate according to an embodiment of this application; Figure 8 is an enlarged schematic diagram of region B in Figure 6; and Figure 9 is a schematic diagram of a deformed insulating plate and electrode assembly in the related art.

[0128] This application provides a battery cell. For example, as shown in Figures 3 to 8, the battery cell 20 includes a housing 21, an electrode assembly 22, and an insulating plate 27.

[0129] The outer casing 21 can be made of steel, aluminum, plastic (such as polypropylene), composite metal (such as copper-aluminum composite), or aluminum-plastic film, etc. In some embodiments, the outer casing 21 can be a sealed structure or a non-sealed structure. As an example, when the outer casing is a non-sealed structure, the outer casing 21 serves to protect the electrode assembly 22, and a sealing bag is also included between the outer casing 21 and the electrode assembly 22. The sealing bag is used to encapsulate the electrode assembly 22 and the electrolyte. Specifically, the sealing bag can be a bag-shaped insulating component or an aluminum-plastic film. When the outer casing 21 is a sealed structure, it is used to encapsulate the electrode assembly 22 and electrolyte components.

[0130] The outer casing 21 includes a first wall 25, which can be any wall of the outer casing 21.

[0131] The battery cell 20 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 batteries, such as hexagonal prismatic batteries.

[0132] In some embodiments, the housing 21 includes an end cap 212 and a housing 211, the housing 211 having an opening, and the end cap 212 covering the opening. The housing 211 may have one or more openings. The end cap 212 may also be provided one or more.

[0133] The electrode assembly 22 can be a wound structure, a stacked structure, or a hybrid structure of wound and stacked.

[0134] In some embodiments, the electrode assembly 22 is a wound structure, with the positive electrode sheet and the negative electrode sheet wound into a wound structure.

[0135] In some embodiments, the electrode assembly 22 is a stacked structure. As an example, multiple positive and negative electrodes can be provided, and multiple positive and multiple negative electrodes can be stacked alternately.

[0136] In some embodiments, the electrode assembly 22 may be cylindrical, flat, or polygonal, etc.

[0137] In some embodiments, the electrode assembly 22 is provided with tabs 222, which can conduct current from the electrode assembly 22. The tabs 222 include a positive tab and a negative tab.

[0138] As an example, the casing 21 is a sealed structure, the battery cell 20 is a square-shaped battery cell, and the electrode assembly 22 is a stacked structure.

[0139] An insulating plate 27 is disposed between the electrode assembly 22 and the first wall 25 of the outer casing 21. The insulating plate 27 is disposed between the surfaces of the electrode assembly 22 and the outer casing 21 facing the electrode assembly 22, and can provide a certain degree of support and fixation for the electrode assembly 22.

[0140] As an example, the battery cell 20 includes two insulating plates 27, at least one of which supports the electrode assembly 22. For example, one insulating plate 27 abuts against the housing 21, while the other insulating plate 27 has a gap with the housing 21. As another example, both insulating plates 27 abut against the housing 21.

[0141] For example, as shown in Figure 9, during the use of the battery cell 20, due to the placement of the battery cell 20, one insulating plate 27 abuts against the electrode assembly 22 and the outer casing 21, while the other insulating plate 27 has a gap with the outer casing 21. Thus, under the weight of the electrode assembly 22, for example, as shown in region E of Figure 9, the insulating plate 27 bends and deforms. Compared to before deformation, the insulating plate 27 exerts more severe pressure on the electrode assembly (for example, before deformation, the insulating plate 27 and the electrode assembly 22 are in surface contact, but when the insulating plate 27 is significantly deformed, the insulating plate 27 and the electrode assembly 22 are in line contact, and the insulating plate 27 exerts more severe pressure on the edges 22a of the electrode assembly 22, increasing the risk of the electrode assembly 22 being damaged).

[0142] The insulating plate 27 includes a middle portion 271 and an end portion 272. Along the length direction of the first wall 25, the end portion 272 is located on both sides of the middle portion 271, and the thickness of the middle portion 271 is greater than the thickness of the end portion 272.

[0143] The length direction of the first wall 25 can be the z-direction in Figure 6.

[0144] As examples, the length direction of the first wall 25 is the same as the length direction of the insulating plate 27. The insulating plate 27 has a plate-like structure, and the dimension of the insulating plate 27 along the length direction is larger than the dimension of the insulating plate 27 along the width and thickness directions. For example, referring to Figures 4 to 8, the length direction of the insulating plate 27 is the z-direction, the thickness direction of the insulating plate 27 is the x-direction, and the width direction is the y-direction.

[0145] Along the length of the insulating plate 27, the middle portion 271 is closer to the center of the insulating plate 27 than the end portion 272.

[0146] Along the length of the insulating plate 27, the middle portion 271 may have the same thickness or different thicknesses. As an example, the middle portion 271 has the same thickness along the length of the insulating plate 27.

[0147] Along the length of the insulating plate 27, the ends 272 may have the same thickness or different thicknesses. As an example, the ends 272 have the same thickness along the length of the insulating plate 27.

[0148] The thickness of the middle portion 271 is greater than that of the end portion 272. This gives the middle portion 271 greater strength and reduces the deformation of the middle portion 271, thereby reducing the risk of the end portion 272 being damaged by excessive deformation of the middle portion 271.

[0149] In this embodiment, the battery cell 20 includes a housing 21, an electrode assembly 22, and an insulating plate 27. The electrode assembly 22 is housed within the housing 21. The insulating plate 27 is disposed between the electrode assembly 22 and the first wall 25 of the housing 21. The insulating plate 27 isolates the electrode assembly 22 from the housing 21 and provides some support for the electrode assembly 22. The thickness of the middle portion 271 of the insulating plate 27 is greater than the thickness of the end portion 272. This increases the strength of the middle portion 271 and reduces the deformation of the middle portion 272, thereby reducing the risk of the end portion 272 being damaged by excessive deformation of the middle portion 271 and improving the reliability of the battery cell 20.

[0150] In some embodiments, along the thickness direction of the first wall 25, the middle portion 271 includes a first intermediate surface 2711 facing the first wall 25, and the end portion 272 includes a first end surface 2721 facing the first wall 25. The first intermediate surface 2711 is closer to the first wall 25 than the first end surface 2721, and the gap between the first intermediate surface 2711 and the first wall 25 is smaller than the gap between the first end surface 2721 and the first wall 25.

[0151] The thickness direction of the first wall 25 can be the x direction in Figure 6.

[0152] As examples, the thickness direction of the first wall 25 is the same as the thickness direction of the insulating plate 27.

[0153] The intermediate portion 271 includes two opposing surfaces along the thickness direction of the first wall 25, namely a first intermediate surface 2711 and a second intermediate surface 2712. The first intermediate surface 2711 faces the first wall 25, and the second intermediate surface 2712 faces the electrode assembly 22.

[0154] The end portion 272 includes two opposing surfaces along the thickness direction of the first wall 25, namely a first end surface 2721 and a second end surface 2722, the first end surface 2721 facing the first wall 25 and the second end surface 2722 facing the electrode assembly 22.

[0155] As shown in Figure 8, along the thickness direction of the first wall 25, the gap between the first intermediate surface 2711 and the first wall 25 is denoted as D, and the gap between the first end surface 2721 and the first wall 25 is denoted as D0, where D is less than D0.

[0156] D and D0 can be measured as follows: along the length of the first wall 25, measure the gap between the first intermediate surface 2711 and the first wall 25 and the gap between the first end surface 2721 and the first wall 25 at multiple locations, and take the average value of the multiple gaps as D and D0 respectively.

[0157] In the above embodiment, along the thickness direction of the first wall 25, the gap between the first intermediate surface 2711 and the first wall 25 is smaller than the gap between the first end surface 2721 and the first wall 25. This can reduce the maximum deformation of the intermediate part and further reduce the risk of the end being damaged by the electrode assembly due to excessive deformation of the intermediate part, which is beneficial to improving the reliability of the battery cell.

[0158] In some embodiments, the gap D between the first intermediate surface 2711 and the first wall 25 satisfies: 0 ≤ D ≤ 0.5 mm.

[0159] D can be 0, 0.1mm, 0.2mm, 0.3mm, 0.4mm, 0.5mm or any value within the above range.

[0160] By setting 0≤D≤0.5mm, the gap between the first intermediate surface 2711 and the first wall 25 of the outer casing 21 is smaller, which can reduce the shaking of the electrode assembly 22 in the outer casing 21. In addition, when the electrode assembly 22 is supported by the insulating plate 27, the smaller gap between the insulating plate 27 and the outer casing 21 is beneficial to reduce the deformation of the insulating plate 27, thereby reducing the squeezing effect of the deformed insulating plate on the electrode assembly 22, reducing the risk of the electrode assembly 22 being crushed, and improving the reliability of the battery cell 20.

[0161] The insulating plate 27 may include only the middle portion 271 and the end portion 272, or it may include a transition portion 273 located between the middle portion 271 and the end portion 272.

[0162] As an example, the insulating plate 27 includes only a middle portion 271 and an end portion 272, the middle portion 271 and the end portion 272 having different thicknesses, and a stepped structure is formed at the connection between the middle portion 271 and the end portion 272.

[0163] In some embodiments, the housing 21 includes a first wall 25 and a second wall 24, the second wall 24 being adjacent to the first wall 25 and having an electrode terminal 240 disposed thereon; the electrode assembly 22 includes a main body 221 and a tab 222 extending from the main body 221; the battery cell 20 further includes an isolation member 23, the isolation member 23 being at least partially disposed between the main body 221 and the second wall 24, and at least a portion of the end 272 being connected to the isolation member 23.

[0164] The isolation member 23 may be partially disposed between the electrode terminal 240 and the main body 221, or it may be disposed entirely between the electrode terminal 240 and the main body 221.

[0165] The isolation member 23 can be a one-piece structure or a split structure. As one example, the isolation member 23 is composed of multiple independently formed parts connected together. As another example, the isolation member 23 is formed by stamping.

[0166] Electrode assembly 22 includes a positive electrode, a negative electrode, and a separator, the separator being located between the positive and negative electrode to isolate them. The positive electrode includes a positive electrode body and a positive tab, and the negative electrode includes a negative electrode body and a negative tab. At least a portion of the positive electrode body is covered by a positive active material, and at least a portion of the positive tab is not covered by the positive active material. At least a portion of the negative electrode body is covered by a negative active material, and at least a portion of the negative tab is not covered by the active material.

[0167] As one example, the main body 221 of the electrode assembly 22 may include a positive electrode body, a negative electrode body, and a separator. As another example, the main body 221 of the electrode assembly 22 may be the portion excluding the tabs 222, where the tabs 222 include a positive tab and a negative tab. For example, the electrode assembly 22 may include multiple stacked positive and negative electrodes, with the positive tabs of the multiple positive electrodes and / or the negative tabs of the multiple negative electrodes forming the tabs 222 of the electrode assembly 22.

[0168] The tab 222 may include at least two parts: one part is located between the main body 221 and the insulating member 23, and the other part is located between the insulating member 23 and the electrode terminal 240. The insulating member 23 can insulate at least a portion of the tab 222 from the end face of the main body 221, thereby reducing the risk of the tab 222 inserting into the main body 221 when the battery cell 20 is affected by external impacts, vibrations, etc., thereby reducing the risk of short circuit in the battery cell 20 and improving the reliability of the battery cell 20.

[0169] Figure 10 is a schematic diagram of the structure of an isolation member according to an embodiment of this application. In some embodiments, as shown in Figure 10, a channel 2330 for the electrode tab 222 to pass through is provided in the middle region along the length direction of the isolation member 23, and the electrode tab 222 passes through the channel 2330 to be electrically connected to the electrode terminal.

[0170] In some embodiments, the isolation member 23 is provided with a slot structure 601, and the second wall 24 of the outer shell 21 is provided with a protrusion structure corresponding to the slot structure 601. The protrusion structure is inserted into the slot structure 601 to achieve the fixation and connection between the isolation member 23 and the second wall 24.

[0171] At least a portion of end 272 is connected to the isolation member 23. End 272 may be fully connected to the isolation member 23 or partially connected to the isolation member 23.

[0172] As an example, a portion of end 272 is connected to the isolation member 23.

[0173] As an example, the end 272 is thermally fused to the end region of the isolation member 23 along its length direction (e.g., the x direction in FIG. 6), thereby achieving the fixation and connection between the insulating plate 27 and the isolation member 23.

[0174] In the above embodiments, the isolation member 23 is at least partially disposed between the electrode terminals 240 of the main body 221, thereby isolating at least a portion of the tab 222 from the main body 221, thereby reducing the risk of short circuit caused by the tab 222 being inserted into the main body 221; in addition, at least a portion of the end 272 of the insulating plate 27 is connected to the isolation member 23, thereby facilitating the connection of the electrode assembly 22, the isolation member 23 and the insulating plate 27 into a whole, reducing the shaking of the electrode assembly 22 in the housing.

[0175] In some embodiments, the thickness H1 of the middle portion 271 satisfies: 0.2mm≤H1≤7mm; and / or, the thickness H2 of the end portion 272 satisfies: 0.1mm≤H2≤2mm.

[0176] The thickness of the intermediate portion 271 can be the average thickness of the intermediate portion 271 at multiple locations. For example, the thickness of the intermediate portion 271 can be measured at multiple locations (e.g., 5 locations) along the length of the insulating plate 27, resulting in multiple thickness values. The average of these multiple thickness values ​​is then used to obtain the thickness H1 of the intermediate portion 271. Similarly, the thickness H2 of the end portion 272 is the average thickness of the end portion 272 at multiple locations, and the measurement method can refer to the method used for measuring the intermediate portion 271.

[0177] H1 can be 0.2mm, 0.5mm, 0.8mm, 0.9mm, 1mm, 2mm, 3mm, 4mm, 5mm, 6mm, 7mm or any value within the above range.

[0178] H2 can be 0.1 mm, 0.15 mm, 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, 0.8 mm, 0.9 mm, 1 mm, 2 mm or any value within the above range.

[0179] When H1 is greater than or equal to 0.2 mm, it is beneficial to reduce or fill the gap between the middle portion 271 of the insulating plate 27 and the outer shell 21, thereby reducing the risk of the electrode assembly 22 shaking in the outer shell 21 and the electrode assembly 22 being squeezed by the end portion 272 of the insulating plate 27; when H1 is less than or equal to 7 mm, it is beneficial to reduce the space occupied by the insulating plate 27 and improve the energy density of the battery cell 20.

[0180] When H2 is greater than or equal to 0.1 mm, the end portion 272 of the insulating plate 27 has a suitable strength, which can reduce the risk of the end portion 272 of the insulating plate 27 breaking; when H2 is less than or equal to 2 mm, it is beneficial to reduce the space occupied by the insulating plate 27 and improve the energy density of the battery cell 20.

[0181] In some embodiments, 0.4 mm ≤ H1 ≤ 5 mm; and / or, 0.3 mm ≤ H2 ≤ 0.5 mm.

[0182] When 0.4 mm ≤ H1 ≤ 5 mm, H1 has a suitable size, which can not only reduce or even fill the gap between the middle portion 271 of the insulating plate 27 and the outer shell 21, reduce the risk of the electrode assembly 22 shaking in the outer shell 21 and the electrode assembly 22 being squeezed by the end portion 272 of the insulating plate 27, but also improve the energy density of the battery cell 20.

[0183] When 0.3 mm ≤ H2 ≤ 0.5 mm, H2 has a suitable size, which is beneficial to both improving the strength of the end portion 272 of the insulating plate 27 and improving the energy density of the battery cell 20.

[0184] In some embodiments, the length L1 of the middle portion 271 satisfies: 1 mm ≤ L1 < L0, and / or, the length L2 of the end portion 272 satisfies: 5 mm ≤ L2 ≤ 0.5L0, where L0 is the length of the main body portion 221 of the electrode assembly 22, and the electrode assembly 22 includes a main body portion 221 and a tab 222 extending from the main body portion 221.

[0185] As an example, as shown in FIG. 4, L0 is the dimension of the main body portion 221 in the z direction.

[0186] By setting L1 to be greater than or equal to 1 mm, the middle part 271 has a certain length, which can provide a certain support for the electrode assembly 22 and reduce the risk of the electrode assembly 22 shaking and being squeezed; by setting L1 to be less than L0, it is convenient to install the insulating plate 27 into the housing and reduce the risk of interference between the insulating plate 27 and the first wall 25 during the assembly of the battery cell 20.

[0187] By setting L2 to be greater than or equal to 5 mm, the connection between the end 272 and the isolation member 23 is facilitated; by setting L2 to be less than or equal to 0.5L0, the end 272 has a suitable length, so the middle part 271 also has a suitable length, the insulating plate 27 has a suitable strength and a good supporting effect on the electrode assembly 22, which is conducive to improving the reliability of the battery cell 20.

[0188] In some embodiments, 10mm ≤ L1 ≤ 250mm; and / or, 5mm ≤ L2 ≤ 100mm.

[0189] L1 can be 10mm, 12mm, 15mm, 18mm, 20mm, 30mm, 40mm, 50mm, 60mm, 70mm, 80mm, 90mm, 100mm, 120mm, 130mm, 140mm, 150mm, 160mm, 180mm, 190mm, 200mm, 220mm, 230mm, 240mm, 250mm or any value within the above range.

[0190] L2 can be 5mm, 8mm, 10mm, 12mm, 15mm, 18mm, 20mm, 24mm, 26mm, 30mm, 40mm, 50mm, 60mm, 70mm, 80mm, 90mm, 100mm or any value within the above range.

[0191] When L1 is greater than or equal to 10 mm, the middle portion 271 can provide some support for the electrode assembly 22, reducing the risk of the electrode assembly 22 shaking or being squeezed. When L1 is less than or equal to 250 mm, the length of the insulating plate 27 can be adapted to the length of the electrode assembly 22, facilitating the assembly and fabrication of the battery cell 20. When L2 is greater than or equal to 5 mm, it facilitates the connection between the end 272 and the insulating member 23. When L2 is less than or equal to 100 mm, the insulating plate 27 has suitable strength and the middle portion 271 also has a suitable length, which helps to improve the reliability of the battery cell 20.

[0192] In some embodiments, 50mm≤L1≤200mm; and / or, 10mm≤L2<30mm.

[0193] When L1 ≤ 200 mm, the middle portion 271 has a suitable length, which can match the length of the electrode assembly 22 and reduce the risk of the electrode assembly 22 shaking or being squeezed. When L2 < 30 mm, the end portion 272 has a suitable length, which facilitates the connection between the insulating plate 27 and the isolation member 23, and also makes it easier to obtain an end portion 272 with a suitable length and an insulating plate 27 with a suitable strength, thereby improving the reliability of the battery cell 20.

[0194] In some embodiments, the insulating plate 27 further includes a transition portion 273, which connects the intermediate portion 271 and the end portion 272; along the length direction of the first wall 25, the transition portion 273 includes a first end and a second end, the first end is connected to the intermediate portion 271, the second end is connected to the end portion 272, and the thickness of the transition portion 273 at the first end is greater than the thickness of the transition portion 273 at the second end.

[0195] The transition portion 273 connects the middle portion 271 and the end portion 272, and the thickness of the transition portion 273 decreases in the direction from the middle portion 271 to the end portion 272.

[0196] By providing the transition section 273, it is easier to insert the insulating plate 27 into the housing 21 during the assembly process of the battery cell 20, thereby reducing the risk of interference between the insulating plate 27 and the housing 21.

[0197] In some embodiments, the transition portion 273 includes a first transition surface 2731 and a second transition surface 2732 opposite to each other along the thickness direction of the insulating plate 27, the second transition surface 2732 protruding from the end portion 272.

[0198] The provision of the first transition surface 2731 and the second transition surface 2732 facilitates the variation of the thickness of the transition portion 273.

[0199] In some embodiments, an arcuate structure is provided at the connection between the second transition surface 2732 and the end 272, and / or at the connection between the second transition surface 2732 and the middle portion 271.

[0200] For example, as shown in Figure 7, the second transition surface 2732 has an arc-shaped structure at the connection between the end portion 272 and the middle portion 271. This makes the connection and transition between the transition portion 273 and the end portion 272 and the middle portion 271 smoother, which helps to reduce the risk of interference between the connection between the transition portion 273 and the end portion 272 and the connection between the transition portion 273 and the middle portion 271 and the housing or electrode assembly 22.

[0201] In some embodiments, the second transition surface 2732 faces the electrode assembly 22, and the first transition surface 2731 faces the first wall 25 of the housing 21. In this way, the connection between the transition portion 273 and the end portion 272, as well as between the transition portion 273 and the middle portion 271, is smoother, which helps to reduce the risk of the second transition surface 2732 damaging the electrode assembly 22, and thus helps to improve the reliability of the battery cell 20.

[0202] Figure 11 is a schematic diagram of the structure of a battery cell according to an embodiment of this application, Figure 12 is a schematic diagram of the structure of an insulating plate according to an embodiment of this application, and Figure 13 is an enlarged schematic diagram of region C of the battery cell in Figure 11. In some embodiments, for example, as shown in Figures 11 to 13, a first groove 281 is provided at the corner 22a of the corresponding electrode assembly 22 of the insulating plate 27, and the first groove 281 is recessed in a direction away from the electrode assembly 22.

[0203] Along the thickness direction of the first wall 25 (x direction in the figure), the first groove 281 is recessed in a direction away from the electrode assembly 22.

[0204] The first groove 281 corresponds to the corner 22a of the electrode assembly 22, thereby forming a space to avoid the corner 22a of the electrode assembly 22, reducing the risk of the insulating plate 27 damaging the electrode assembly 22, and improving the reliability of the battery cell 20.

[0205] The first groove 281 can be disposed at the end 272 of the insulating plate 27, or at the middle part 271, or at the transition part 273, or at the connection between the end 272 and the transition part 273. The position of the first groove 281 is related to the relative position of the electrode assembly 22 and the insulating plate 27, and can be set according to the size and relative position of the electrode assembly 22 and the insulating plate 27.

[0206] In some embodiments, the transition portion 273 includes a first transition surface 2731 and a second transition surface 2732 that are opposite each other along the thickness direction of the first wall 25, the second transition surface 2732 protruding from the end portion 272 and facing the first wall 25 of the housing 21; the end portion 272 includes a first end surface 2721 and a second end surface 2722 that are opposite each other along the thickness direction of the first wall 25, the second end surface 2722 facing the housing 21; a first groove 281 is disposed on the first transition surface 2731, or the first groove 281 is disposed on the second end surface 2722, or the first groove 281 is disposed at the junction of the first transition surface 2731 and the second end surface 2722.

[0207] As an example, as shown in Figures 12 and 13, a first groove 281 is provided at the junction of a first transition surface 2731 and a second end surface 2722.

[0208] In other examples, the first groove 281 may also be provided on the first transition surface 2731 or the second end surface 2722. The specific position of the first groove 281 may be set according to the relative position of the electrode assembly 22 and the insulating plate 27.

[0209] By providing the first groove 281, a relief space for avoiding the edges 22a of the electrode assembly 22 can be formed, reducing the risk of the transition portion 273 damaging the electrode assembly 22, which is beneficial to improving the reliability of the battery cell 20.

[0210] In some embodiments, the relationship between the depth H3 of the first groove 281, the thickness H1 of the middle portion 271, and the thickness H2 of the end portion 272 satisfies: 0.3H2 ≤ H3 < H2.

[0211] The depth of the first groove 281 is the dimension of the first groove 281 along the thickness direction of the first wall 25 (e.g., the x direction in FIG. 11).

[0212] As an example, along the length direction of the first groove 281 (the z direction in FIG. 11), the depth of the first groove 281 is measured at multiple positions, and the average value of the measured multiple depth values is taken to obtain H3.

[0213] H3 can be 0.3H2, 0.4H2, 0.5H2, 0.6H2, 0.7H2, 0.8H2, 0.9H2 or any value within the above range.

[0214] When H3 is greater than or equal to 0.2H2, the edges 22a of the electrode assembly 22 can be avoided, reducing the risk of the insulating plate 27 damaging the electrode assembly 22; when H3 is less than H2, the insulating plate 27 has a relatively appropriate strength at the first groove 281, reducing the risk of the insulating plate 27 breaking at the first groove 281.

[0215] In some embodiments, 0.2 mm ≤ H3 < 2 mm.

[0216] H3 can be 0.2 mm, 0.3 mm, 0.5 mm, 0.6 mm, 0.8 mm, 1 mm, 1.2 mm, 1.4 mm, 1.6 mm, 1.8 mm, 2 mm or any value within the above range.

[0217] When H3 is greater than or equal to 0.2 mm, the edges 22a of the electrode assembly 22 can be avoided, reducing the risk of the insulating plate 27 damaging the electrode assembly 22; when H3 is less than or equal to 2 mm, the insulating plate 27 has a relatively appropriate strength at the first groove 281, reducing the risk of the insulating plate 27 breaking at the first groove 281.

[0218] In some embodiments, 0.3mm ≤ H3 ≤ 0.5mm. In this way, the first groove 281 has a suitable depth, which is beneficial for avoiding the sharp corners 22a of the electrode assembly 22 and reducing the risk of the electrode assembly 22 being crushed, while the insulating plate 27 also has a suitable strength.

[0219] In some embodiments, along the length of the first wall 25, the dimension L3 of the first groove 281 satisfies: 1mm≤L3≤20mm.

[0220] L3 can be 1mm, 2mm, 3mm, 5mm, 6mm, 8mm, 10mm, 12mm, 14mm, 15mm, 16mm, 18mm, 20mm or any value within the above range.

[0221] When L3 is greater than or equal to 1 mm, the sharp edges of the electrode assembly 22 can be avoided, reducing the risk of the insulating plate 27 damaging the electrode assembly 22; when L3 is less than or equal to 20 mm, the insulating plate 27 has a suitable strength at the first groove 281, which can reduce the risk of the insulating plate 27 breaking at the first groove 281.

[0222] In some embodiments, 3mm ≤ L3 ≤ 15mm. In this way, the first groove 281 has a suitable length, which is beneficial for avoiding the sharp corners 22a of the electrode assembly 22 and reducing the risk of the electrode assembly 22 being crushed, while the insulating plate 27 also has a suitable strength.

[0223] In some embodiments, the length L5 of the transition portion 273 satisfies: 0 <L5≤60mm。

[0224] L5 can be 0.5mm, 1mm, 2mm, 3mm, 5mm, 6mm, 8mm, 10mm, 12mm, 14mm, 15mm, 16mm, 18mm, 20mm, 30mm, 40mm, 50mm, 60mm or any value within the above range.

[0225] When L5 is greater than 0, the transition portion 273 has a certain length, which facilitates the insertion of the insulating plate 27 into the housing 21; when L5 is less than or equal to 60 mm, the transition portion 273 has a suitable length, so that the middle portion 271 and the end portion 272 can also have suitable lengths, and the insulating plate 27 provides good support for the electrode assembly 22 and has suitable strength.

[0226] In some embodiments, 2mm ≤ L5 ≤ 20mm. In this way, the transition portion 273 has a suitable length, which facilitates the insertion of the insulating plate 27 into the housing 21 and is also beneficial to obtaining an insulating plate 27 with good support effect and suitable strength for the electrode assembly 22.

[0227] Figure 14 is a schematic diagram of a battery cell according to an embodiment of this application; Figure 15 is a schematic diagram of the structure of an insulating plate according to an embodiment of this application; Figure 16 is an enlarged schematic diagram of region D in Figure 14; and Figure 17 is a schematic diagram of the structure of an insulating plate according to an embodiment of this application.

[0228] In some embodiments, for example as shown in Figures 14 to 17, at least one second groove 282 is provided on the side of the insulating plate 27 facing the housing 21 along the thickness direction of the first wall 25.

[0229] The insulating plate 27 has at least one second groove 282 on the side facing the outer casing 21. For example, one second groove 282, two or more second grooves 282 may be provided.

[0230] The second groove 282 can be a groove extending along the y-direction, and the second groove 282 can serve as an exhaust channel. For example, when thermal runaway occurs in the battery cell 20, the material inside the battery cell 20 can flow through the exhaust channel formed by the second groove 282 to the pressure relief mechanism of the battery cell 20, and then be discharged from the battery cell 20 through the pressure relief mechanism.

[0231] As an example, as shown in Figures 14 to 16, the intermediate portion 271 includes a first intermediate surface 2711 and a second intermediate surface 2712 disposed opposite to each other along the thickness direction of the first wall 25. The second intermediate surface 2712 faces the outer casing 21 and is provided with a second groove 282.

[0232] In the structure shown in Figures 14 to 16, the transition portion 273 includes a first transition surface 2731 and a second transition surface 2732 that are opposite each other along the thickness direction of the first wall 25. The second transition surface 2732 protrudes from the end portion 272 and faces the outer shell 21. The end portion 272 includes a first end surface 2721 and a second end surface 2722 that are opposite each other along the thickness direction of the first wall 25. The second end surface 2722 faces the outer shell 21. A first groove 281 is provided at the connection between the first transition surface 2731 and the first end surface 2721. The second intermediate surface 2712 of the intermediate portion 271 is provided with a second groove 282.

[0233] As another example, as shown in FIG16, a second groove 282 is provided on the side of the middle portion 271 and the transition portion 273 facing the outer casing 21.

[0234] In the structure shown in FIG17, the transition portion 273 includes a first transition surface 2731 and a second transition surface 2732 that are opposite each other along the thickness direction of the first wall 25. The second transition surface 2732 protrudes from the end 272. An arc-shaped structure is provided at the connection between the second transition surface 2732 of the transition portion 273 and the end 272 and the intermediate portion 271. The intermediate portion 271 includes a first intermediate surface 2711 and a second intermediate surface 2712 that are opposite each other along the thickness direction of the first wall 25. The second intermediate surface 2712 is provided with a plurality of second grooves 282. The second intermediate surface 2712 faces the outer shell 21.

[0235] By providing at least one second groove 282 on the side of the insulating plate 27 facing the outer casing 21, it is beneficial to form an exhaust channel on the insulating plate 27, which facilitates the discharge of high-temperature and high-pressure substances inside the battery cell 20 in the event of thermal runaway.

[0236] In some embodiments, a plurality of second grooves 282 are provided on the side of the insulating plate 27 facing the outer casing 21, and the plurality of second grooves 282 are spaced apart along the length direction of the first wall 25. By providing a plurality of second grooves 282, it is beneficial to form a plurality of exhaust channels, which is beneficial to the discharge of high-temperature and high-pressure substances inside the battery cell 20 in the event of thermal runaway.

[0237] In some embodiments, the total projected area S1 of at least one second groove 282 on the first plane and the projected area S0 of the insulating plate 27 on the first plane satisfy: 0.05S0≤S1≤0.5S0; the first plane is parallel to the length direction and thickness direction of the insulating plate 27.

[0238] The projected area S0 of the insulating plate 27 on the first plane can be the area of ​​the region filled by the cross-sectional line in Figure 15.

[0239] The total projected area S1 of at least one second groove 282 on the first plane is S1 = N × L4 × H4, where N is the number of second grooves 282, L4 is the dimension of the second groove 282 along the length of the first wall 25, and H4 is the depth of the second groove.

[0240] S1 can be 0.05S0, 0.1S0, 0.2S0, 0.3S0, 0.4S0, 0.5S0, or any value within the above range.

[0241] When S1 is greater than or equal to 0.05S0, the exhaust channel formed by the second groove 282 has a suitable exhaust area, which facilitates the smooth discharge of high-temperature and high-pressure substances inside the battery cell 20 in the event of thermal runaway. When S1 is less than or equal to 0.5S0, the insulating plate 27 has a suitable strength and provides suitable support for the electrode assembly 22, which can reduce the risk of the electrode assembly 22 being crushed and shaking inside the housing 21.

[0242] In some embodiments, the depth H4 of the second groove 282 satisfies: 0.2mm≤H4≤5mm, and / or, along the length direction of the first wall 25, the size L4 of the second groove 282 satisfies: 1mm≤L4≤20mm.

[0243] L4 can be 1mm, 2mm, 3mm, 5mm, 6mm, 8mm, 10mm, 12mm, 14mm, 15mm, 16mm, 18mm, 20mm or any value within the above range.

[0244] H4 can be 0.2mm, 0.3mm, 0.5mm, 0.6mm, 0.8mm, 1mm, 1.2mm, 1.4mm, 1.6mm, 1.8mm, 2mm, 3mm, 4mm, 5mm or any value within the above range.

[0245] When H4 is greater than or equal to 0.2 mm, the second groove 282 has a suitable depth to facilitate the passage of gases and other emissions within the battery cell 20. When H4 is less than or equal to 5 mm, the middle portion 271 has suitable strength to provide good support for the electrode assembly 22, reducing the risk of the electrode assembly 22 being crushed or shaking within the casing 21. When L4 is greater than or equal to 1 mm, the second groove 282 has a suitable length to facilitate the passage of gases and other emissions within the battery cell 20. When L4 is less than or equal to 20 mm, the middle portion 271 has suitable strength to provide good support for the electrode assembly 22, reducing the risk of the electrode assembly 22 being crushed or shaking within the casing 21.

[0246] In some embodiments, 0.2mm ≤ H4 ≤ 5mm, and / or 3mm ≤ L4 ≤ 15mm.

[0247] When the diameter is 0.2mm≤H4≤5mm, it facilitates the passage of gases and other emissions within the battery cell 20, while also reducing the risk of the electrode assembly 22 being damaged by pressure and shaking within the casing 21. When the diameter is 3mm≤L4≤15mm, it facilitates the passage of gases and other emissions within the battery cell 20, while also reducing the risk of the electrode assembly 22 being damaged by pressure and shaking within the casing 21.

[0248] In some embodiments, the middle portion 271 of the insulating plate 27 abuts against the inner sidewall of the housing 21. This reduces the risk of the electrode assembly 22 shifting within the housing 21.

[0249] In some embodiments, the materials of the insulating member 23 and the insulating plate 27 include thermoplastic insulating materials.

[0250] Thermoplastic insulating materials can include polyethylene, polypropylene, polyimide, etc.

[0251] As an example, the materials of the isolation member 23 and the insulating plate 27 are polypropylene.

[0252] The materials of the isolation component 23 and the insulating plate 27 include thermoplastic insulating materials. During the preparation of the battery cell 20, the connection between the isolation component 23 and the insulating plate 27 can be achieved by heating the insulating plate 27 and the insulating plate 27.

[0253] In some embodiments, the battery cell 20 includes two second walls 24 and two first walls 25, wherein the second walls 24 and the first walls 25 are perpendicular to each other.

[0254] Both second walls 24 are provided with electrode terminals 240, one of which is a positive electrode terminal and the other is a negative electrode terminal. Correspondingly, the battery cell 20 includes two isolation members 23, and the positive and negative electrodes of the electrode assembly 22 are arranged opposite to each other along the length direction of the first wall 25. The battery cell 20 includes two insulating plates 27, which are located between the electrode assembly 22 and the two first walls 25 respectively.

[0255] In some embodiments, the first wall 25 is provided with a pressure relief mechanism, and the insulating plate 27 is provided with a pressure relief area at the position corresponding to the pressure relief mechanism.

[0256] The pressure relief mechanism is used to release the internal gas of the battery cell 20.

[0257] As an example, the internal pressure or temperature of a battery cell is actuated to release the internal pressure or temperature when it reaches a predetermined threshold. When the internal pressure or temperature of the battery cell reaches the predetermined threshold, the pressure relief mechanism is activated or a weak structure in the pressure relief mechanism is broken, thereby creating an opening or channel for the internal pressure or temperature to be released. The threshold design varies depending on the design requirements. The threshold may depend on the materials of one or more of the positive electrode, negative electrode, electrolyte, and separator in the battery cell.

[0258] As an example, the pressure relief mechanism can be integrally formed with the first wall 25.

[0259] As an example, the pressure relief mechanism can also be set and connected to the first wall 25 separately.

[0260] The term "actuation" as used in this application refers to the pressure relief mechanism being activated or undergoing a certain state, thereby releasing the internal pressure and temperature of the battery cell 20. The actions of the pressure relief mechanism may include, but are not limited to: movement of components within the pressure relief mechanism to form an exhaust channel, rupture, breakage, tearing, or opening of at least a portion of the pressure relief mechanism, etc. When the pressure relief mechanism is actuated, the high-temperature, high-pressure substances inside the battery cell 20 are discharged outwards from the actuated portion as waste. This method enables pressure and temperature relief of the battery cell under controllable pressure or temperature, thereby preventing potentially more serious accidents.

[0261] In some embodiments, when the housing 21 is a non-sealed structure, the pressure relief mechanism can be configured as a through hole for discharging gas inside the battery cell 20.

[0262] The emissions from the battery cell 20 mentioned in this application include, but are not limited to: electrolyte, dissolved or split positive and negative electrode plates, fragments of separators, high-temperature and high-pressure gases generated by the reaction, flames, etc.

[0263] The pressure relief area can be a through hole or a groove. For example, the second groove 282 can serve as a pressure relief area. Alternatively, the insulating plate 27 may have a through hole positioned to correspond to the pressure relief mechanism, facilitating the discharge of high-temperature, high-pressure substances from inside the battery cell 20.

[0264] In some embodiments, the battery cell 20 includes an insulating film 26, which is sleeved on the outer surface of the electrode assembly 22 and has an inner side of the housing; an insulating plate 27 is at least partially disposed between the insulating film 26 and the electrode assembly 22. In this way, the insulating film 26, the electrode assembly 22, and the insulating plate 27 are connected to form a whole, which facilitates the assembly of the battery cell 20.

[0265] The insulating film 26 is made of thermoplastic insulating materials. For example, the insulating film 26 is made of polypropylene.

[0266] In some embodiments, the electrode assembly 22 includes alternately stacked first and second electrodes, one of which is a positive electrode and the other is a negative electrode.

[0267] 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.

[0268] As an example, multiple negative electrode sheets can be provided, and positive electrode sheets can be folded to form multiple stacked folded segments, with a negative electrode sheet sandwiched between adjacent folded segments.

[0269] As an example, both the positive and negative electrode plates are folded to form multiple stacked folded segments.

[0270] As an example, multiple separators can be provided, each positioned between any adjacent positive or negative electrode plates.

[0271] As an example, the separators can be continuously arranged, either by folding or rolling between any adjacent positive or negative electrode plates.

[0272] In the above embodiments, the battery cell 20 including the electrode assembly 22 is a stacked battery cell, and the battery cell 20 has a high energy density.

[0273] In some embodiments, the second electrodes of the first electrode are stacked alternately in a first direction, which is perpendicular to the thickness and length directions of the first wall 25. This results in minimal change in the gap between the insulating plate 27 and the outer casing 21 during the cycling process of the battery cell 20.

[0274] According to some embodiments of this application, this application also provides a battery device 10, including a battery cell 20 as described in any of the above embodiments.

[0275] As an example, the battery device 10 includes a plurality of battery cells 20, and each of the plurality of battery cells 20 is arranged in such a way that the thickness direction of the insulating plate 27 is parallel to the direction of gravity, that is, a first wall 25 of the battery cell 20 faces the top cover or bottom wall of the battery device 10.

[0276] 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 20, which are connected in series, parallel, or mixed connections via busbars.

[0277] In some embodiments, a battery cell assembly is typically formed by arranging multiple battery cells 20.

[0278] As an example, a battery cell assembly can be a battery module, which is formed by arranging and fixing multiple battery cells together to form an independent module. As another example, a battery module can be formed by bundling multiple battery cells together with cable ties.

[0279] In some embodiments, the battery device may be a battery pack, which includes a housing and one or more individual battery cells housed within the housing.

[0280] 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.

[0281] As an example, battery cell assemblies can also be housed in a housing by directly fixing multiple battery cells to the housing.

[0282] As an example, the enclosure may include a first enclosure and a second enclosure. The first enclosure and the second enclosure are fastened together to form a closed space inside the enclosure to house the individual battery cells. Here, "closed" refers to covering or closing, and can be either sealed or unsealed. The first enclosure may be a top cover or a bottom plate.

[0283] 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.

[0284] In some embodiments, the housing may be part of the vehicle's chassis structure. For example, a portion of the housing may be at least a part of the vehicle's floor, or a portion of the housing may be at least a part of the vehicle's crossbeams and longitudinal beams.

[0285] According to some embodiments of this application, this application also provides an electrical device including the battery device described in any of the above embodiments, and the battery device is used to provide electrical energy to the electrical device.

[0286] The electrical equipment can be any of the aforementioned devices or systems that utilize battery devices.

[0287] According to some embodiments of this application, referring to Figures 14 to 17, this application provides a battery cell 20, including a housing 21, an electrode assembly 22, an insulating member 23, and an insulating plate 27. The insulating plate 27 is disposed between the first wall 25 of the housing 21 and the electrode assembly 22, and the second wall 24 of the housing 21 is provided with electrode terminals 240. The insulating member 23 is disposed between the main body 221 of the electrode assembly 22 and the electrode terminals 240. The insulating plate 27 includes a middle portion 271, a transition portion 273, and an end portion 272 disposed along the length direction of the insulating plate. The thickness of the middle portion 271 is greater than the thickness of the end portion 272. A first groove 281 is provided on the side of the insulating plate 27 facing the electrode assembly 22 at the corner 22a corresponding to the electrode assembly 22, and a plurality of second grooves 282 are provided on the side of the insulating plate 27 facing the housing 21. With the above settings, the shaking of the electrode assembly 22 inside the housing 21 can be reduced, and the risk of the edge 22a of the electrode assembly being crushed can be reduced. At the same time, the battery cell 20 also has a lot of venting channels inside, so the battery cell 20 has high reliability.

[0288] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and not to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application, and they should all be covered within the scope of the claims and specification of this application. In particular, as long as there is no structural conflict, the various technical features mentioned in the embodiments can be combined in any way. This application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A battery cell, characterized in that, Comprising: A housing (21), the housing (21) including a first wall (25); An electrode assembly (22), the electrode assembly (22) being received in the housing (21); An insulating plate (27), the insulating plate (27) being disposed between the electrode assembly (22) and the first wall (25), the insulating plate (27) including a middle portion (271) and end portions (272), along the length direction of the first wall (25), the end portions (272) being located on both sides of the middle portion (271), and the thickness of the middle portion (271) being greater than the thickness of the end portions (272).

2. The battery cell according to claim 1, characterized in that, Along the thickness direction of the first wall (25), the middle portion (271) includes a first middle surface (2711) facing the first wall (25), the end portions (272) include first end surfaces (2721) facing the first wall (25), the first middle surface (2711) is closer to the first wall (25) than the first end surfaces (2721), and the gap between the first middle surface (2711) and the first wall (25) is smaller than the gap between the first end surfaces (2721) and the first wall (25).

3. The battery cell according to claim 2, characterized in that, The gap D between the first middle surface (2711) and the first wall (25) satisfies: 0 ≤ D ≤ 0.5 mm.

4. The battery cell according to any one of claims 1-3, characterized in that, The housing (21) includes the first wall (25) and a second wall (24), the second wall (24) being adjacent to the first wall (25), and the second wall (24) is provided with electrode terminals (240); The electrode assembly (22) includes a main body portion (221) and a tab (222) extending from the main body portion (221); The battery cell further includes an isolation member (23), the isolation member (23) being at least partially disposed between the main body portion (221) and the second wall (24), and at least part of the end portions (272) is connected to the isolation member (23).

5. The battery cell according to any one of claims 1-4, characterized in that, The thickness H1 of the middle portion (271) satisfies: 0.2 mm ≤ H1 ≤ 7 mm; and / or, the thickness H2 of the end portions (272) satisfies: 0.1 mm ≤ H2 ≤ 2 mm.

6. The battery cell according to claim 5, characterized in that, 0.4 mm ≤ H1 ≤ 5 mm; and / or, 0.3 mm ≤ H2 ≤ 0.5 mm.

7. The battery cell according to any one of claims 1-6, characterized in that, The length L1 of the middle portion (271) satisfies: 1 mm ≤ L1 < L0, and / or, the length L2 of the end portions (272) satisfies: 5 mm ≤ L2 ≤ 0.5L0, where L0 is the length of the main body portion (221) of the electrode assembly (22), and the electrode assembly (22) includes the main body portion (221) and a tab (222) extending from the main body portion (221).

8. The battery cell according to claim 7, characterized in that, 10 mm ≤ L1 ≤ 250 mm; and / or, 5 mm ≤ L2 ≤ 100 mm.

9. The battery cell according to claim 8, characterized in that, 50 mm ≤ L1 ≤ 200 mm; and / or, 10 mm ≤ L2 < 30 mm.

10. The battery cell according to any one of claims 1-9, characterized in that, The insulating plate (27) further includes a transition portion (273), the transition portion (273) connecting the middle portion (271) and the end portions (272); Along the length of the first wall (25), the transition portion (273) includes a first end and a second end, the first end being connected to the middle portion (271) and the second end being connected to the end portion (272), and the thickness of the transition portion (273) at the first end being greater than the thickness of the transition portion (273) at the second end.

11. The battery cell according to claim 10, characterized in that, The transition portion (273) includes a first transition surface (2731) and a second transition surface (2732) opposite to each other along the thickness direction of the first wall (25), the second transition surface (2732) protruding from the end portion (272).

12. The battery cell according to claim 11, characterized in that, An arc-shaped structure is provided at the connection between the second transition surface (2732) and the end (272), and / or at the connection between the second transition surface (2732) and the middle portion (271).

13. The battery cell according to claim 12, characterized in that, The second transition surface (2732) faces the electrode assembly (22), and the first transition surface (2731) faces the first wall (25).

14. The battery cell according to any one of claims 10-13, characterized in that, The insulating plate (27) is provided with a first groove (281) at the corner (22a) corresponding to the electrode assembly (22), and the first groove (281) is recessed in a direction away from the electrode assembly (22).

15. The battery cell according to claim 14, characterized in that, The transition portion (273) includes a first transition surface (2731) and a second transition surface (2732) opposite each other along the thickness direction of the first wall (25), the second transition surface (2732) protruding from the end (272) and facing the first wall (25); The end portion (272) includes a first end surface (2721) and a second end surface (2722) opposite each other along the thickness direction of the first wall (25), the first end surface (2721) facing the first wall (25); The first groove (281) is disposed on the first transition surface (2731), or the first groove (281) is disposed on the second end surface (2722), or the first groove (281) is disposed at the connection between the first transition surface (2731) and the second end surface (2722).

16. The battery cell according to claim 14 or 15, characterized in that, The relationship between the depth H3 of the first groove (281), the thickness H1 of the middle part (271), and the thickness H2 of the end part (272) satisfies: 0.3H2≤H3 <H2。 17. The battery cell according to claim 16, characterized in that, 0.2mm≤H3<2mm.

18. The battery cell according to claim 17, characterized in that, 0.3mm≤H3≤0.5mm.

19. The battery cell according to any one of claims 14-18, characterized in that, Along the length of the first wall (25), the dimension L3 of the first groove (281) satisfies: 1mm≤L3≤20mm.

20. The battery cell according to claim 19, characterized in that, 3mm≤L3≤15mm.

21. The battery cell according to any one of claims 10-20, characterized in that, The length L5 of the transition section (273) satisfies: 0 <L5≤60mm。 22. The battery cell according to claim 21, characterized in that, 2mm≤L5≤20mm.

23. The battery cell according to any one of claims 1-22, characterized in that, Along the thickness direction of the first wall (25), at least one second groove (282) is provided on the side of the insulating plate (27) facing the outer shell (21).

24. The battery cell according to claim 23, characterized in that, The insulating plate (27) has a plurality of second grooves (282) on the side facing the outer shell (21), and the plurality of second grooves (282) are spaced apart along the length direction of the first wall (25).

25. The battery cell according to claim 23 or 24, characterized in that, The total projected area S1 of the at least one second groove (282) on the first plane and the projected area S0 of the insulating plate (27) on the first plane satisfy: 0.05S0≤S1≤0.5S0; The first plane is parallel to the length and thickness directions of the insulating plate (27).

26. The battery cell according to any one of claims 23-25, characterized in that, The depth H4 of the second groove (282) satisfies: 0.2mm≤H4≤5mm, and / or, along the length direction of the first wall (25), the size L4 of the second groove (282) satisfies: 1mm≤L4≤20mm.

27. The battery cell according to claim 26, characterized in that, 0.2mm≤H4≤5mm, and / or, 3mm≤L4≤15mm.

28. The battery cell according to any one of claims 4-27, characterized in that, The materials of the isolation member (23) and the insulating plate (27) include thermoplastic insulating materials.

29. The battery cell according to any one of claims 4-28, characterized in that, The battery cell includes two second walls (24) and two first walls (25), with the second walls (24) and the first walls (25) being perpendicular to each other.

30. The battery cell according to any one of claims 1-29, characterized in that, The battery cell includes an insulating film (26), which is sleeved on the outer surface of the electrode assembly (22) and has the inner side of the outer shell (21). The insulating plate (27) is at least partially disposed between the insulating film (26) and the electrode assembly (22).

31. The battery cell according to any one of claims 1-30, characterized in that, The electrode assembly (22) includes alternating stacked first and second electrodes, one of which is a positive electrode and the other is a negative electrode.

32. A battery device, characterized in that, It includes multiple battery cells according to any one of claims 1-31.

33. An electrical appliance, characterized in that, It includes a plurality of battery cells according to any one of claims 1-31 or a battery device according to claim 32, wherein the battery cells or the battery device are used to store or provide electrical energy.

Images