Battery cells, battery devices and power-consuming devices

Abstract

The present application provides a battery cell, a battery device and an electrical device, wherein the battery cell comprises an electrode assembly and an insulating member; the positive electrode plate of the electrode assembly comprises a positive electrode body and a positive electrode tab at one end along a first direction connected to a positive electrode current collecting layer of the positive electrode body, and along the first direction, an end of the negative electrode body of the negative electrode plate close to the positive electrode tab is the first end, and the negative electrode tab is connected to the first end; the insulating member is arranged at an end of the positive electrode active material layer of the positive electrode body close to the positive electrode tab along the first direction, and covers a part of the surface of the positive electrode current collecting layer facing the positive electrode active material layer, the insulating member comprises a first insulating portion and a second insulating portion, the first insulating portion is arranged between the second insulating portion and the positive electrode active material layer, the thickness of the first insulating portion is greater than the thickness of the second insulating portion, and the first insulating portion extends beyond the first end along the first direction, which is beneficial to improving energy density and reducing the risk of tab redundancy, thereby improving the reliability of the battery cell.

Description

Technical Field

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

[0002] Batteries are widely used in new energy vehicles, electronic equipment and other fields. As the demand for batteries increases, higher requirements are placed on battery reliability. As the market's requirements for battery life increase, the requirements for battery reliability are also increasing. Summary of the invention

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

[0004] In a first aspect, an embodiment of the present application provides a battery cell, comprising an electrode assembly and an insulating member; the electrode assembly comprises a positive electrode sheet and a negative electrode sheet, the positive electrode sheet comprises a positive electrode body and a positive electrode tab, the negative electrode sheet comprises a negative electrode body and a negative electrode tab, the positive electrode tab is connected to one end of the positive electrode body along a first direction, along the first direction, the end of the negative electrode body close to the positive electrode tab is a first end, the negative electrode tab is connected to the first end, the positive electrode body comprises a positive current collecting layer and a positive active material layer, the positive electrode tab is connected to the positive current collecting layer, the positive electrode collecting The positive electrode active material layer is arranged on at least one side of the current collecting layer along its thickness direction; the insulating member is arranged at one end of the positive electrode active material layer close to the positive electrode tab along the first direction, and covers a part of the surface of the positive current collecting layer facing the positive electrode active material layer, the insulating member includes a first insulating portion and a second insulating portion arranged and connected along the first direction, the first insulating portion is arranged between the second insulating portion and the positive electrode active material layer, the thickness of the first insulating portion is greater than the thickness of the second insulating portion, and the first insulating portion extends beyond the first end along the first direction.

[0005] In the above technical solution, the insulating member includes a first insulating portion and a second insulating portion arranged and connected along the first direction, the first insulating portion is arranged between the second insulating portion and the positive electrode active material layer, the thickness of the first insulating portion is greater than the thickness of the second insulating portion, the first insulating portion exceeds the first end along the first direction, the negative electrode tab is connected to the first end of the negative electrode body, then the first end can be considered as the die-cutting position of the negative electrode tab, and also the position where the burr is generated, the first insulating portion with a larger thickness exceeds the first end, then the first insulating portion can separate the first end and the positive electrode sheet, and the first insulating portion can separate the negative electrode tab and the positive electrode sheet, the first insulating portion has a larger thickness, reducing the risk of the burr of the negative electrode tab piercing the insulating member and the separator at the same time, after the burr of the negative electrode tab pierces the separator, the first insulating portion of the insulating member can play the role of insulating separation between the negative electrode tab and the positive electrode sheet, thereby reducing the risk of short circuit of the battery cell and improving the reliability of the battery cell. The second insulating portion with a smaller thickness is arranged close to the positive electrode tab, which can alleviate the problem of increasing the size of the electrode assembly and thus causing energy density loss when the positive electrode tab is bent. Since the thickness of the second insulating part is small, the size of the positive pole tab after bending is small, so a smaller positive pole tab bending space can be reserved in the first direction, for example, by increasing the width of the area corresponding to the positive active material layer of the positive pole sheet, so that the space reserved for the positive pole tab bending in the first direction in the shell of the battery cell is reduced, thereby improving the energy density of the battery cell. The thickness of the second insulating part is less than that of the first insulating part, and it can also reduce the risk of tab redundancy, thereby further reducing the risk of short circuit of the battery cell and further improving the reliability of the battery cell.

[0006] In some embodiments of the first aspect of the present application, the thickness of the first insulating portion is D1, the thickness of the second insulating portion is D2, and D1-D2≥20 μm.

[0007] In the above technical solution, D1-D2≥20μm, so that the thickness of the first insulating part can be set larger, and the thickness of the second insulating part is set smaller, reducing the risk of burrs generated by die-cutting the negative electrode tabs piercing the separator and the insulating member at the same time, thereby reducing the risk of short circuit of the battery cell and improving the reliability of the battery cell. The smaller thickness of the second insulating part can alleviate the problem of increased size of the electrode assembly and thus loss of energy density when the positive electrode tab is bent. Since the thickness of the second insulating part is set smaller, the size of the positive electrode tab after bending is smaller, so a smaller positive electrode tab bending space can be reserved in the first direction, such as by increasing the width of the corresponding area of ​​the positive active material layer of the positive electrode sheet, so that the space reserved for the positive electrode tab bending in the first direction in the outer shell of the battery cell is reduced, thereby improving the energy density of the battery cell. The smaller thickness of the second insulating part can also reduce the risk of tab redundancy, thereby further reducing the risk of short circuit of the battery cell and further improving the reliability of the battery cell.

[0008] In some embodiments of the first aspect of the present application, the thickness of the first insulating portion is D1, 30 μm≤D1≤80 μm.

[0009] In the above technical solution, 30μm≤D1 makes the thickness of the first insulating part larger, reducing the risk of burrs generated by die-cutting the negative electrode tab piercing the first insulating part, thereby reducing the risk of short circuit of the battery cell and improving the reliability of the battery cell. D1≤80μm alleviates the problem of reduced energy density of the battery cell due to the installation of insulating parts, so that the battery cell has higher reliability and higher energy density.

[0010] In some embodiments of the first aspect of the present application, the thickness of the second insulating portion is D2, 10 μm≤D2≤60 μm.

[0011] In the above technical solution, 10μm≤D2 makes the thickness of the second insulating part large enough, which not only enables the second insulating part to play a good insulating role between the positive electrode sheet and the negative electrode sheet, but also reduces the risk of burrs generated when die-cutting the negative electrode tab piercing the second insulating part, thereby reducing the risk of short circuit of the battery cell, which is conducive to improving the reliability of the battery cell. D2≤60μm reduces the influence of the insulating part of the battery cell on the energy density of the battery cell, so that the battery cell has higher reliability and higher energy density.

[0012] In some embodiments of the first aspect of the present application, along the thickness direction of the positive electrode tab, the positive electrode tab has a first surface, and the second insulating portion covers a portion of the first surface.

[0013] In the above technical solution, the second insulating portion covers a portion of the first surface of the positive electrode tab, and the second insulating portion can insulate and separate the positive electrode tab and the negative electrode sheet. The second insulating portion can form a double insulating separation with the isolation membrane between the positive electrode tab and the negative electrode sheet, further reducing the risk of short circuit of the battery cell and improving the reliability of the battery cell. After the isolation membrane is punctured, the second insulating portion can continue to play the role of insulating and separating the positive electrode tab and the negative electrode sheet, which is beneficial to reduce the risk of short circuit of the battery cell after the burr of the positive electrode tab punctures the isolation membrane, and improve the reliability of the battery cell. In addition, the second insulating portion is relatively thin, which is also convenient for bending the positive electrode tab, thereby reducing the size of the electrode assembly in the first direction.

[0014] In some embodiments of the first aspect of the present application, the first insulating portion covers a portion of the first surface.

[0015] In the above technical solution, the first insulating part covers a part of the first surface, and the first insulating part can cover the positive electrode tab, so that the first insulating part can insulate and separate the negative electrode tab and the positive electrode tab, and the first insulating part can form a double insulation separation with the separator between the positive electrode tab and the negative electrode tab, further reducing the risk of short circuit of the battery cell and improving the reliability of the battery cell. After the burrs generated by die-cutting the negative electrode tab pierce the separator, the first insulating part can continue to play an insulating and separating role between the negative electrode tab and the positive electrode tab, reducing the risk of short circuit of the battery cell and improving the reliability of the battery cell.

[0016] In some embodiments of the first aspect of the present application, the positive electrode current collecting layer includes a first region covered by the positive electrode active material layer and a second region not covered by the positive electrode active material layer, the first region and the second region are arranged and connected along the first direction, the positive electrode tab is connected to an end of the second region away from the first region, and the insulating member covers the second region.

[0017] In the above technical solution, the positive electrode current collecting layer includes a first area covered by the positive electrode active material layer and a second area not covered by the positive electrode active material layer. The first area and the second area are arranged and connected along the first direction. The positive electrode ear is connected to the end of the second area away from the first area, which is convenient for die-cutting to form the positive electrode ear. The second area provides an installation position for the insulating member. The insulating member covers the second area and can form a double insulating separation between the negative electrode plate and the positive electrode plate together with the isolation membrane, further reducing the risk of short circuit of the battery cell and improving the reliability of the battery cell. After the burrs generated by die-cutting the negative electrode ear pierce the isolation membrane, the insulating member can continue to play the role of insulating separation, which is conducive to reducing the risk of short circuit of the battery cell and improving the reliability of the battery cell.

[0018] In some embodiments of the first aspect of the present application, along the first direction, a size of the second area is H1, 1mm≤H1≤5mm.

[0019] In the above technical solution, 1mm≤H1 allows sufficient distance between the positive electrode active material layer and the die-cutting position of the positive electrode tab, reducing the risk of damaging the positive electrode active material layer during die-cutting. H1≤5mm controls the size of the second region, alleviating the problem of energy density loss of the battery cell caused by the second region without the positive electrode active material layer.

[0020] In some embodiments of the first aspect of the present application, 2mm≤H1≤3mm.

[0021] In the above technical solution, 2mm≤H1 makes the distance between the positive electrode active material layer and the die-cutting position of the positive electrode tab larger, further reducing the risk of damaging the positive electrode active material layer during die-cutting. H1≤3mm further alleviates the problem of energy density loss of the battery cell due to the second area where the positive electrode active material layer is not provided.

[0022] In some embodiments of the first aspect of the present application, the first insulating portion includes a first part and a second part, the first part and the second part are stacked along the thickness direction of the positive electrode sheet, the second part is connected to the surface of the first part away from the positive electrode current collecting layer, and the first part connects the positive electrode active material layer and the second insulating portion.

[0023] In the above technical solution, the first insulating part includes a first part and a second part stacked along the thickness direction of the positive electrode plate. When manufacturing the insulating part, the first part and the second part with smaller thickness can be manufactured in steps. The first part and the second part together form a first insulating part with larger thickness, which facilitates the manufacturing and molding of the first insulating part.

[0024] In some embodiments of the first aspect of the present application, the first portion and the second insulating portion have the same thickness.

[0025] In the above technical solution, the thickness of the first part and the second insulating part are the same, which facilitates the connection of the first part and the second insulating part and facilitates the manufacture of the insulating part.

[0026] In some embodiments of the first aspect of the present application, the first portion and the second insulating portion are integrally formed.

[0027] In the above technical solution, the first part and the second insulating part are integrally formed, which facilitates the manufacture of the insulating part.

[0028] In some embodiments of the first aspect of the present application, the first part and the second part are made of the same material.

[0029] In the above technical solution, the first part and the second part are made of the same material, which facilitates the first part and the second part to form a stable connection relationship and also facilitates the manufacture of the insulating part.

[0030] In some embodiments of the first aspect of the present application, the first part and the second part are made of different materials.

[0031] In the above technical solution, the first part and the second part are made of different materials, which facilitates the selection of appropriate materials for the first part and the second part respectively, so that the overall structural performance formed by the insulating part and the positive electrode plate is better.

[0032] In some embodiments of the first aspect of the present application, the first portion and the second insulating portion are made of the same material.

[0033] In the above technical solution, the first part and the second insulating part are made of the same material, which facilitates the manufacturing and molding of the insulating part.

[0034] In some embodiments of the first aspect of the present application, the first portion and the second insulating portion are made of different materials.

[0035] In the above technical solution, the first part and the second insulating part are made of different materials, which facilitates the selection of appropriate materials for the first part and the second insulating part, so that the overall structural performance formed by the insulating part and the positive electrode sheet is better.

[0036] In some embodiments of the first aspect of the present application, the first insulating part includes a first part and a second part, the positive electrode active material layer and the positive electrode current collecting layer are both connected to the first part, a first accommodating part is provided on the surface of the first part facing the positive electrode current collecting layer, and the second part is accommodated in the first accommodating part and connected to the second insulating part.

[0037] In the above technical solution, the first insulating part includes a first portion and a second portion. When manufacturing the insulating part, the first portion and the second portion can be manufactured in steps. The first portion and the second portion together form a first insulating part with a larger thickness, which facilitates the manufacturing and molding of the first insulating part. When the second insulating part and the second portion are integrally formed, the second portion is accommodated in the first accommodating portion and connected to the second insulating part, which is equivalent to increasing the connection area between the first insulating part and the second insulating part, so that the connection between the first insulating part and the second insulating part is more stable.

[0038] In some embodiments of the first aspect of the present application, along the thickness direction of the first insulating portion, the surface of the positive electrode active material layer facing away from the positive electrode current collecting layer is farther away from the positive electrode current collecting layer than the surface of the first insulating portion facing away from the positive electrode current collecting layer.

[0039] In the above technical solution, the surface of the positive active material layer away from the positive current collecting layer is farther away from the positive current collecting layer than the surface of the first insulating part away from the positive current collecting layer, so as to avoid the insulating member increasing the distance between the positive electrode sheet and the negative electrode sheet, which is beneficial for the battery cell to have better cycle performance. The surface of the positive active material layer away from the positive current collecting layer is farther away from the positive current collecting layer than the surface of the first insulating member away from the positive current collecting layer, which can also make the insulating member fully utilize the space between the positive electrode sheet and the negative electrode sheet, and the insulating member occupies a smaller space, which is beneficial for the battery cell to have better energy density.

[0040] In some embodiments of the first aspect of the present application, the positive electrode plate further includes an adhesive layer, which is disposed between the positive electrode active material layer and the positive electrode current collecting layer and connects the positive electrode active material layer and the positive electrode current collecting layer.

[0041] In the above technical solution, the positive electrode active material layer and the positive electrode current collecting layer are connected by the adhesive layer, which can improve the connection stability between the positive electrode active material layer and the positive electrode current collecting layer and is also beneficial to improving the strength of the positive electrode sheet.

[0042] In some embodiments of the first aspect of the present application, the positive electrode current collecting layer includes a first region covered by the positive electrode active material layer and a second region not covered by the positive electrode active material layer, the first region and the second region are arranged and connected along the first direction, the first pole ear is connected to an end of the second region away from the first region, and the insulating member covers the second region; along the first direction, the bonding layer includes an overhanging portion extending beyond one end of the positive electrode active material layer close to the insulating member, and the overhanging portion covers at least a portion of the second region.

[0043] In the above technical solution, the adhesive layer includes a protruding portion that protrudes beyond one end of the positive electrode active material layer close to the insulating member, and the protruding portion covers at least a portion of the second region not covered by the positive electrode active material layer, thereby increasing the coverage area of ​​the adhesive layer on the positive electrode current collecting layer, which is beneficial to improving the strength of the positive electrode sheet. The adhesive layer has a protruding portion, and the insulating member and the second region can be connected through the protruding portion of the adhesive layer, which is beneficial to improving the connection stability of the insulating member.

[0044] In some embodiments of the first aspect of the present application, the first insulating portion is connected to the protruding portion.

[0045] In the above technical solution, the first insulating portion is connected to the protruding portion, which is beneficial to improving the bonding stability between the insulating member and the positive electrode current collecting layer.

[0046] In some embodiments of the first aspect of the present application, the first insulating portion has a second accommodating portion, and the protruding portion is accommodated in the second accommodating portion and connected to the first insulating portion.

[0047] In the above technical solution, the protruding portion is accommodated in the second accommodating portion of the first insulating portion and connected to the first insulating portion, so that the connection area between the insulating member and the adhesive layer is larger, the bonding stability is better, and it is also beneficial to reduce the volume of the overall structure formed by the positive electrode sheet and the insulating member.

[0048] In some embodiments of the first aspect of the present application, a thickness of the adhesive layer is less than or equal to a thickness of the second insulating portion.

[0049] In the above technical solution, the thickness of the adhesive layer is less than or equal to the thickness of the second insulating part, and the adhesive layer can be made small enough to alleviate the problem of reducing the energy density of the battery cell due to the provision of the adhesive layer.

[0050] In some embodiments of the first aspect of the present application, the bonding layer includes a carbon coating.

[0051] In the above technical solution, the bonding layer includes a carbon coating, which can not only increase the bonding performance between the positive electrode current collecting layer and the positive electrode active material layer, but also enhance the conductivity between the positive electrode current collecting layer and the positive electrode active material layer.

[0052] In some embodiments of the first aspect of the present application, along the first direction, the width of the positive electrode active material layer is D3, the width of the bonding layer is D4, and 0.1 mm≤D4-D3≤5 mm.

[0053] In the above technical solution, 0.1mm≤D4-D3 increases the coverage area of ​​the adhesive layer on the positive electrode current collecting layer, which is beneficial to enhance the strength of the positive electrode sheet. D4-D3≤5mm reduces the space occupied by the adhesive layer and alleviates the problem of energy density loss of the battery cell due to the setting of the adhesive layer.

[0054] In some embodiments of the first aspect of the present application, 0.5 mm ≤ D4 - D3 ≤ 1 mm.

[0055] In the above technical solution, 0.5mm≤D4-D3 further increases the coverage area of ​​the adhesive layer on the positive current collecting layer, which is conducive to further enhancing the strength of the positive electrode sheet. D4-D3≤1mm further reduces the space occupied by the adhesive layer, thereby further alleviating the problem of energy density loss of the battery cell due to the setting of the adhesive layer.

[0056] In a second aspect, an embodiment of the present application provides a battery device, comprising a battery cell provided by any of the above embodiments.

[0057] In the above technical solution, the above battery cell has good reliability, and the battery device including the battery cell has good reliability.

[0058] In a third aspect, an embodiment of the present application provides an electrical device, comprising a battery cell provided by any of the above embodiments or a battery device provided by the above embodiments.

[0059] In the above technical solution, the reliability of the above battery cells and battery devices is good, which is beneficial to improving the power consumption reliability of the power-consuming devices powered by the battery cells and the power-consuming devices. BRIEF DESCRIPTION OF THE DRAWINGS

[0060] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0061] Figure 1A schematic diagram of the structure of a vehicle provided in some embodiments of the present application;

[0062] Figure 2 An exploded view of a battery device provided in some embodiments of the present application;

[0063] Figure 3 An exploded view of a battery cell provided for some embodiments of the present application;

[0064] Figure 4 A schematic diagram of the structure of a battery cell provided in some embodiments of the present application;

[0065] Figure 5 for Figure 4 A1-A1 sectional view;

[0066] Figure 6 for Figure 5 A schematic diagram of the structure of the electrode assembly in the middle shell;

[0067] Figure 7 for Figure 6 Schematic diagram of the relative position relationship between the positive electrode piece, the separator, the negative electrode piece and the insulating member;

[0068] Figure 8 for Figure 7 A schematic diagram of a positive electrode sheet provided with an insulating member from a perspective;

[0069] Fig. 9 for Figure 7 Another perspective schematic diagram of a positive electrode sheet provided with an insulating member;

[0070] Fig.10 A schematic diagram of a current collector provided with a positive electrode active material layer and an insulating member before die-cutting a positive electrode tab;

[0071] Fig.11 A schematic diagram of a positive electrode plate provided with an insulating member from one perspective provided in some other embodiments of the present application;

[0072] Fig.12 A schematic diagram of a positive electrode sheet provided with an insulating member from another perspective provided in some embodiments of the present application;

[0073] Fig.13 A schematic diagram of the structure of a positive electrode sheet provided with an insulating member provided in some other embodiments of the present application;

[0074] Fig.14 A schematic structural diagram of a positive electrode sheet provided with an insulating member provided in yet other embodiments of the present application;

[0075] Fig.15 A schematic structural diagram of a positive electrode sheet provided with an insulating member provided in some further embodiments of the present application;

[0076] Fig.16 A schematic structural diagram of a positive electrode sheet provided with an insulating member provided in yet other embodiments of the present application;

[0077] Fig.17 A schematic structural diagram of a positive electrode plate provided with an insulating member is provided in some other embodiments of the present application.

[0078] Icon: 1000-vehicle; 100-battery device; 10-housing; 11-first housing; 12-second housing; 20-battery cell; 21-housing; 211-housing; 2111-opening; 212-end cover; 22-electrode assembly; 221-positive electrode sheet; 2211-positive electrode body; 22111-positive electrode current collecting layer; 22111'-current collector; 221111-first region; 221112-second region; 22112-positive electrode active material layer; 2212-positive electrode ear; 22121-first surface; 22121a-first region; 2 2121b-second zone; 2213-adhesive layer; 22131-extension portion; 222-negative electrode sheet; 2221-negative electrode body; 22211-first end; 2222-negative electrode ear; 223-isolation film; 23-electrode terminal; 24-insulating member; 241-first insulating portion; 2411-first part; 2412-second part; 2413-first accommodating portion; 2414-second accommodating portion; 242-second insulating portion; 200-controller; 300-motor; X-first direction; X'-width direction of current collector; Y-thickness direction of positive electrode sheet. DETAILED DESCRIPTION

[0079] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0080] Unless otherwise defined, all technical and scientific terms used in this application have the same meanings as those commonly understood by technicians in the technical field of this application; the terms used in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned drawings and any variations thereof are intended to cover non-exclusive inclusions. The terms "first", "second", etc. in the specification and claims of this application or the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order or a primary and secondary relationship.

[0081] Reference to "embodiment" in this application means that a particular feature, structure, or characteristic described in conjunction with the embodiment may be included in at least one embodiment of the present application. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments.

[0082] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", and "attached" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0083] The term "and / or" in this application is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this application generally indicates that the associated objects before and after are in an "or" relationship.

[0084] In the embodiments of the present application, the same reference numerals represent the same components, and for the sake of brevity, detailed descriptions of the same components are omitted in different embodiments. It should be understood that the thickness, length, width and other dimensions of various components in the embodiments of the present application shown in the drawings, as well as the overall thickness, length, width and other dimensions of the integrated device are only exemplary descriptions and should not constitute any limitation to the present application.

[0085] The term “plurality” used in this application refers to two or more (including two).

[0086] In the embodiment of the present application, the battery cell may be a secondary battery. A secondary battery refers to a battery cell that can be continuously used by activating active materials by charging after the battery cell is discharged.

[0087] Battery cells include, but are not limited to, lithium-ion batteries, sodium-ion batteries, sodium-lithium-ion batteries, lithium metal batteries, sodium metal batteries, lithium-sulfur batteries, magnesium-ion batteries, nickel-hydrogen batteries, nickel-cadmium batteries, lead-acid batteries, and the like.

[0088] A battery cell generally includes an electrode assembly. The electrode assembly includes a positive electrode, a negative electrode, and a separator. During the charge and discharge process of the battery cell, active ions (such as lithium ions) are embedded and removed between the positive electrode and the negative electrode. The separator is set between the positive electrode and the negative electrode to reduce the risk of short circuit between the positive and negative electrodes, while allowing active ions to pass through.

[0089] In some embodiments, the positive electrode may be a positive electrode sheet, and the positive electrode sheet may include a positive electrode current collector and a positive electrode active material disposed on at least one surface of the positive electrode current collector.

[0090] As an example, the positive electrode current collector has two surfaces facing each other in its thickness direction, and the positive electrode active material is disposed on either or both of the two facing surfaces of the positive electrode current collector.

[0091] As an example, the positive electrode current collector may be a metal foil or a composite current collector. For example, as the metal foil, aluminum with a silver-plated surface, stainless steel with a silver-plated surface, stainless steel, copper, aluminum, nickel, carbon electrode, carbon, nickel or titanium, etc. may be used. The composite current collector may include a polymer material base layer and a metal layer. The composite current collector may be formed by forming a metal material (aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0092] As an example, the positive electrode active material may include at least one of the following materials: lithium-containing phosphates, lithium transition metal oxides, and their respective modified compounds. However, the present application is not limited to these materials, and other traditional materials that can be used as positive electrode active materials for battery cells may also be used. These positive electrode active materials may be used alone or in combination of two or more. Among them, examples of lithium-containing phosphates may include, but are not limited to, at least one of lithium iron phosphate (such as LiFePO4 (also referred to as LFP)), a composite material of lithium iron phosphate and carbon, lithium manganese phosphate (such as LiMnPO4), a composite material of lithium manganese phosphate and carbon, lithium iron manganese phosphate, and a composite material of lithium iron manganese phosphate and carbon. Examples of lithium transition metal oxides may include, but are not limited to, lithium cobalt oxide (such as LiCoO2), lithium nickel oxide (such as LiNiO2), lithium manganese oxide (such as LiMnO2, LiMn2O4), lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, lithium nickel cobalt manganese oxide (such as LiNi 1 / 3 Co 1 / 3Mn 1 / 3 O2 (also referred to as NCM 333 )、LiNi 0.5 Co 0.2 Mn 0.3 O2 (also referred to as NCM 523 )、LiNi 0.5 Co 0.25 Mn 0.25 O2 (also referred to as NCM 211 )、LiNi 0.6 Co 0.2 Mn 0.2O2 (also referred to as NCM 622 )、LiNi 0.8 Co 0.1 Mn 0.1 O2 (also referred to as NCM 811 ), lithium nickel cobalt aluminum oxide (such as LiNi 0.85 Co 0.15 Al 0.05 O2) and its modified compounds, etc.

[0093] In some embodiments, the positive electrode may be a foamed metal. The foamed metal may be a nickel foam, a copper foam, an aluminum foam, an alloy foam, etc. When the foamed metal is used as the positive electrode, the positive electrode active material may not be provided on the surface of the foamed metal, but of course, the positive electrode active material may also be provided. As an example, a lithium source material, potassium metal or sodium metal may also be filled or / and deposited in the foamed metal, and the lithium source material is lithium metal and / or a lithium-rich material.

[0094] In some embodiments, the negative electrode may be a negative electrode sheet, and the negative electrode sheet may include a negative electrode current collector.

[0095] As an example, the negative electrode current collector may be a metal foil, a foamed metal or a composite current collector. For example, as the metal foil, aluminum with a silver-plated surface, stainless steel with a silver-plated surface, stainless steel, copper, aluminum, nickel, carbon electrode, carbon, nickel or titanium, etc. may be used. The foamed metal may be foamed nickel, foamed copper, foamed aluminum, foamed alloy, etc. The composite current collector may include a polymer material base layer and a metal layer. The composite current collector may be formed by forming a metal material (copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0096] 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.

[0097] As an example, the negative electrode current collector has two surfaces facing each other in its thickness direction, and the negative electrode active material is disposed on either or both of the two facing surfaces of the negative electrode current collector.

[0098] As an example, the negative electrode active material may adopt the negative electrode active material for battery cells known in the art. As an example, the negative electrode active material may include at least one of the following materials: artificial graphite, natural graphite, soft carbon, hard carbon, silicon-based materials, tin-based materials, lithium titanate, etc. The silicon-based material may be selected from at least one of elemental silicon, silicon oxide compounds, silicon-carbon composites, silicon-nitrogen composites, and silicon alloys. The tin-based material may be selected from at least one of elemental tin, tin oxide compounds, and tin alloys. However, the present application is not limited to these materials, and other traditional materials that can be used as negative electrode active materials for battery cells may also be used. These negative electrode active materials may be used alone or in combination of two or more.

[0099] In some embodiments, the material of the positive electrode current collector may be aluminum, and the material of the negative electrode current collector may be copper.

[0100] In some embodiments, the separator is a separator membrane, which can be any known porous separator membrane with good chemical stability and mechanical stability.

[0101] As an example, the material of the separator may include at least one of glass fiber, non-woven fabric, polyethylene, polypropylene and polyvinylidene fluoride. The separator may be a single-layer film or a multi-layer composite film. When the separator is a multi-layer composite film, the materials of each layer may be the same or different. The separator may be a separate component located between the positive and negative electrodes, or may be attached to the surface of the positive and negative electrodes.

[0102] In some embodiments, the separator is a solid electrolyte, which is disposed between the positive electrode and the negative electrode and serves to transmit ions and isolate the positive and negative electrodes.

[0103] In some embodiments, the battery cell further includes an electrolyte, which plays a role in conducting ions between the positive and negative electrodes. The electrolyte can be liquid, gel or solid. Among them, the liquid electrolyte includes an electrolyte salt and a solvent.

[0104] In some embodiments, the electrolyte salt may include at least one of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium hexafluoroarsenate, lithium bisfluorosulfonyl imide, lithium bistrifluoromethanesulfonyl imide, lithium trifluoromethanesulfonate, lithium difluorophosphate, lithium difluorooxalatoborate, lithium dioxalatoborate, lithium difluorodioxalatophosphate, and lithium tetrafluorooxalatophosphate.

[0105] In some embodiments, the solvent may include at least one of ethylene carbonate, propylene carbonate, ethyl methyl carbonate, diethyl carbonate, dimethyl carbonate, dipropyl carbonate, methyl propyl carbonate, ethyl propyl carbonate, butylene carbonate, fluoroethylene carbonate, methyl formate, methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, propyl propionate, methyl butyrate, ethyl butyrate, 1,4-butyrolactone, cyclopentane, dimethyl sulfone, methyl ethyl sulfone and diethyl sulfone. The solvent may also be an ether solvent. The ether solvent may include one or more of ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, 1,3-dioxolane, tetrahydrofuran, methyltetrahydrofuran, diphenyl ether and crown ether.

[0106] Among them, the gel electrolyte includes a skeleton network with a polymer as the electrolyte, combined with an ionic liquid-lithium salt.

[0107] Among them, solid electrolytes include polymer solid electrolytes, inorganic solid electrolytes, and composite solid electrolytes.

[0108] As an example, the polymer solid electrolyte may be polyether (polyethylene oxide), polysiloxane, polycarbonate, polyacrylonitrile, polyvinylidene fluoride, polymethyl methacrylate, a single ion polymer, polyionic liquid-lithium salt, cellulose, and the like.

[0109] As an example, the inorganic solid electrolyte may include an oxide solid electrolyte (crystalline perovskite, sodium superconducting ion conductor, garnet, amorphous LiPON film), a sulfide solid electrolyte (crystalline lithium superion conductor (lithium germanium phosphosulfide, silver germanium sulfide), amorphous sulfide) and one or more of a halide solid electrolyte, a nitride solid electrolyte and a hydride solid electrolyte.

[0110] As an example, the composite solid electrolyte is formed by adding an inorganic solid electrolyte filler to a polymer solid electrolyte.

[0111] In some embodiments, the electrode assembly is a wound structure, wherein the positive electrode sheet and the negative electrode sheet are wound into a wound structure.

[0112] In some embodiments, the electrode assembly is a laminate structure.

[0113] As an example, a plurality of positive electrode sheets and a plurality of negative electrode sheets may be provided respectively, and the plurality of positive electrode sheets and the plurality of negative electrode sheets may be alternately stacked.

[0114] As an example, a plurality of positive electrode sheets may be provided, and the negative electrode sheet is folded to form a plurality of stacked folded segments, with a positive electrode sheet sandwiched between adjacent folded segments.

[0115] As an example, both the positive electrode sheet and the negative electrode sheet are folded to form a plurality of stacked folded sections.

[0116] As an example, a plurality of separators may be provided, each of which is provided between any adjacent positive electrode sheets or negative electrode sheets.

[0117] As an example, the separator may be disposed continuously, and may be disposed between any adjacent positive electrode sheets or negative electrode sheets by folding or winding.

[0118] In some embodiments, the shape of the electrode assembly can be cylindrical, flat, or polygonal.

[0119] In some embodiments, the electrode assembly is provided with tabs, which can lead current out of the electrode assembly. The tabs include a positive tab and a negative tab.

[0120] In some embodiments, the battery cell may include a housing. The housing is used to encapsulate components such as the electrode assembly and the electrolyte. The housing may be a steel housing, an aluminum housing, a plastic housing (such as polypropylene), a composite metal housing (such as a copper-aluminum composite housing), or an aluminum-plastic film.

[0121] As an example, the battery cell may be a cylindrical battery cell, a prismatic battery cell, a soft-pack battery cell or a battery cell of other shapes. The prismatic battery cell includes a square-shell battery cell, a blade-shaped battery cell, a polygonal battery cell, such as a hexagonal battery cell.

[0122] The battery apparatus mentioned in the embodiments of the present application may include one or more battery cell assemblies for providing voltage and capacity. The battery cell assembly may include multiple battery cells, which are connected in series, in parallel or in mixed connection through a busbar.

[0123] In some embodiments, a battery cell assembly is generally formed by arranging a plurality of battery cells; as an example, the battery cell assembly may be a battery module, which is formed by arranging and fixing a plurality of battery cells to form an independent module.

[0124] As an example, a battery module may be formed by bundling a plurality of battery cells by cable ties.

[0125] In some embodiments, the battery device may be a battery pack, which may include a case and one or more battery cell assemblies, wherein the battery cell assemblies are accommodated in the case.

[0126] As an example, the battery cell assembly may be a battery module, and the battery cell assembly may be accommodated in the box by fixing the battery module in the box.

[0127] As an example, the battery cell assembly may also be housed in the case by directly fixing a plurality of battery cells to the case.

[0128] As an example, the box may include a first box and a second box. The first box and the second box are buckled together to form a closed space inside the box to accommodate the battery cell assembly. The closed here means covered or closed, which can be sealed or unsealed. The first box can be a top cover or a bottom plate.

[0129] As an example, the box body may include a top cover, a frame and a bottom plate. The top cover and the bottom plate are respectively connected to the frame, so that a closed space is formed inside the box body to accommodate the battery cell assembly.

[0130] As an example, the box body can be used as a part of the chassis structure of the vehicle. For example, the top cover of the box body can become at least a part of the floor of the vehicle, or the frame of the box body can become at least a part of the cross beam and longitudinal beam of the vehicle.

[0131] In some embodiments, the battery device refers to an energy storage device, which includes a box body, at least one side of which is provided with a door. The energy storage device includes an energy storage container, an energy storage cabinet, and the like.

[0132] Batteries have outstanding advantages such as high energy density, low environmental pollution, high power density, long service life, wide adaptability, and low self-discharge coefficient. They are an important part of the development of new energy today. The development of battery technology must consider many design factors at the same time, such as performance parameters such as energy density, cycle life, discharge capacity, and charge and discharge rate. In addition, the reliability of the battery must also be considered.

[0133] The negative electrode sheet of the battery cell includes a negative electrode body and a negative electrode ear, the negative electrode ear is connected to one end of the negative electrode body along the first direction, the negative electrode ear is formed by die-cutting the negative electrode collector of the negative electrode sheet, and die-cutting the negative electrode ear is prone to burrs. The positive electrode sheet of the battery cell includes a positive electrode body and a positive electrode ear, the positive electrode ear is connected to one end of the positive electrode body along the first direction, and the positive electrode current collecting layer of the positive electrode body is provided with an insulating member in the area near the positive electrode ear. The insulating member is used to reduce the risk of the burrs generated when die-cutting the negative electrode ear piercing the isolation membrane and causing the battery cell to short-circuit. In order to achieve this purpose, the insulating member needs to be thicker to avoid being pierced by the burrs, but if the insulating member is too thick, the size of the positive electrode ear in the first direction will be larger after the positive electrode ear is bent, which will increase the energy density loss of the battery cell and the redundant ear situation, and reduce the reliability of the battery cell; if the thickness of the insulating member is too small, the burrs generated by die-cutting the negative electrode ear will easily pierce the insulating member and cause a short circuit, and the reliability of the battery cell is low.

[0134] Based on the above considerations, in order to alleviate the problem that the insulating part arranged on the positive electrode plate is too thick, which will increase the energy density loss of the battery cell and cause the tab redundancy, thereby reducing the reliability of the battery cell, and the insulating part is too thin, and the insulating part is easily punctured by burrs, causing a short circuit in the battery cell, an embodiment of the present application provides a battery cell, the battery cell includes an electrode assembly and an insulating part; the electrode assembly includes a positive electrode plate and a negative electrode plate, the positive electrode plate includes a positive electrode body and a positive electrode tab, the negative electrode plate includes a negative electrode body and a negative electrode tab, the positive electrode tab is connected to one end of the positive electrode body along a first direction, along the first direction, the end of the negative electrode body close to the positive electrode tab is the first end, and the negative electrode body is close to the positive electrode tab. The tab is connected to the first end, the positive electrode body includes a positive current collecting layer and a positive active material layer, the positive tab is connected to the positive current collecting layer, and the positive current collecting layer is provided with a positive active material layer on at least one side along the thickness direction thereof; the insulating member is provided at one end of the positive active material layer close to the positive tab along the first direction X, and covers a part of the surface of the positive current collecting layer facing the positive active material layer, the insulating member includes a first insulating portion and a second insulating portion arranged and connected along the first direction, the first insulating portion is provided between the second insulating portion and the positive active material layer, the thickness of the first insulating portion is greater than the thickness of the second insulating portion, and the first insulating portion extends beyond the first end along the first direction.

[0135] The insulating member includes a first insulating portion and a second insulating portion arranged and connected along a first direction, the first insulating portion is arranged between the second insulating portion and the positive electrode active material layer, the thickness of the first insulating portion is greater than the thickness of the second insulating portion, the first insulating portion extends beyond the first end along the first direction, the negative electrode tab is connected to the first end of the negative electrode body, then the first end can be considered as the die-cutting position of the negative electrode tab, and also the position where the burr is generated, the first insulating portion with a larger thickness extends beyond the first end, then the first insulating portion can separate the first end and the positive electrode sheet, and the first insulating portion can separate the negative electrode tab and the positive electrode sheet, the first insulating portion has a larger thickness, reducing the risk of the burr of the negative electrode tab piercing the insulating member and the separator at the same time, after the burr of the negative electrode tab pierces the separator, the first insulating portion of the insulating member can play the role of insulating separation between the negative electrode tab and the positive electrode sheet, thereby reducing the risk of short circuit of the battery cell and improving the reliability of the battery cell. The second insulating portion with a smaller thickness is arranged close to the positive electrode tab, which can alleviate the problem of increasing the size of the electrode assembly and thus causing energy density loss when the positive electrode tab is bent. Since the thickness of the second insulating part is small, the size of the positive pole tab after bending is small, so a smaller positive pole tab bending space can be reserved in the first direction, for example, by increasing the width of the area corresponding to the positive active material layer of the positive pole sheet, so that the space reserved for the positive pole tab bending in the first direction in the shell of the battery cell is reduced, thereby improving the energy density of the battery cell. The thickness of the second insulating part is less than that of the first insulating part, and it can also reduce the risk of tab redundancy, thereby further reducing the risk of short circuit of the battery cell and further improving the reliability of the battery cell.

[0136] The technical solutions described in the embodiments of the present application are applicable to various electrical devices that use battery cells and battery devices, such as mobile phones, portable devices, laptops, electric vehicles, electric toys, electric tools, vehicles, ships and spacecraft, for example, spacecraft include airplanes, rockets, space shuttles and spacecraft, etc.

[0137] For the convenience of description, the following embodiments are described by taking the electric device as a vehicle as an example.

[0138] Please refer to Figure 1 , Figure 1 The schematic diagram of the structure of the vehicle 1000 provided in some embodiments of the present application. The vehicle 1000 is provided with a battery device 100 inside, and the battery device 100 can be provided at the bottom, head or tail of the vehicle 1000. The battery device 100 can be used to power the vehicle 1000, for example, the battery device 100 can be used as an operating power source of the vehicle 1000.

[0139] The vehicle 1000 may further include a controller 200 and a motor 300 , wherein the controller 200 is used to control the battery device 100 to supply power to the motor 300 , for example, to meet the power requirements of starting, navigating, and driving the vehicle 1000 .

[0140] In some embodiments of the present application, the battery device 100 can not only serve as an operating power source for the vehicle 1000, but also serve as a driving power source for the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0141] Please refer to Figure 2 , Figure 2 This is an exploded view of a battery device 100 provided in some embodiments of the present application. The battery device 100 may include a case 10 and a battery cell 20 . The case 10 is used to accommodate the battery cell 20 .

[0142] Among them, a closed space for accommodating the battery cell 20 is formed inside the box 10. The box 10 can adopt a variety of structures. In some embodiments, the box 10 may include a first box 11 and a second box 12, and the first box 11 and the second box 12 are buckled with each other. The first box 11 and the second box 12 can be in various shapes, such as a cuboid, a cylinder, etc. The first box 11 can be a hollow structure with one side open, and the second box 12 can also be a hollow structure with one side open. The open side of the second box 12 is buckled with the open side of the first box 11 to form a box 10 with a closed space. It is also possible that the first box 11 is a hollow structure with one side open, and the second box 12 is a plate-like structure. The second box 12 is buckled on the open side of the first box 11, so as to form a box 10 with a accommodating space.

[0143] In the battery device 100, there may be one or more battery cells 20. If there are more than one battery cell 20, the battery cells 20 may be connected in series, in parallel, or in a mixed connection. A mixed connection means that the battery cells 20 are connected in series and in parallel. A battery module may be formed by connecting a plurality of battery cells 20 in series, in parallel, or in a mixed connection, and then the plurality of battery modules are connected in series, in parallel, or in a mixed connection to form a whole and accommodated in the box 10. Alternatively, all the battery cells 20 may be directly connected in series, in parallel, or in a mixed connection, and then the whole formed by all the battery cells 20 is accommodated in the box 10.

[0144] In some embodiments, the battery device 100 may further include a busbar component (not shown in the figure), and the multiple battery cells 20 may be electrically connected through the busbar component to achieve series connection, parallel connection, or mixed connection of the multiple battery cells 20. The busbar component may be a metal conductor, such as copper, iron, aluminum, stainless steel, aluminum alloy, etc.

[0145] Please refer to Figure 3 and Figure 4 , Figure 3 An exploded view of a battery cell 20 provided in some embodiments of the present application, Figure 4 This is a schematic structural diagram of a battery cell 20 provided in some embodiments of the present application; the battery cell 20 may include a housing 21 and an electrode assembly 22 , and the electrode assembly 22 is accommodated in the housing 21 .

[0146] In some embodiments, the housing 21 may include a shell 211 and an end cap 212, wherein the shell 211 has an opening 2111, and the end cap 212 closes the opening 2111 of the shell 211. The closing here means covering or closing, which may be sealed or unsealed.

[0147] The shell 211 is a component for accommodating the electrode assembly 22. The shell 211 may be a hollow structure with an opening 2111 formed at one end, or a hollow structure with openings 2111 formed at opposite ends. The shell 211 may be in various shapes, such as a cylindrical shape, a rectangular parallelepiped shape, etc. The material of the shell 211 may be various, such as copper, iron, aluminum, steel, aluminum alloy, etc. The electrode assembly 22 may be partially located in the shell 211, or may be completely located in the shell 211.

[0148] The end cap 212 and the shell 211 together define a receiving space for accommodating the electrode assembly 22 and other components. The end cap 212 can be connected to the shell 211 by welding, crimping, etc. to close the opening 2111 of the shell 211. The shape of the end cap 212 can be adapted to the shape of the shell 211. For example, the shell 211 is a rectangular parallelepiped structure, and the end cap 212 is a rectangular plate structure adapted to the shell 211. For another example, the shell 211 is a cylindrical structure, and the end cap 212 is a circular plate structure adapted to the shell 211. The material of the end cap 212 can also be a variety of materials, such as copper, iron, aluminum, steel, aluminum alloy, etc. The material of the end cap 212 and the shell 211 can be the same or different.

[0149] In the embodiment where the housing 211 forms an opening 2111 at one end, one end cap 212 may be provided accordingly. In the embodiment where the housing 211 forms openings 2111 at two opposite ends, two end caps 212 may be provided accordingly, and the two end caps 212 respectively close the two openings 2111 of the housing 211, and the two end caps 212 and the housing 211 together define a receiving space.

[0150] In some embodiments, the battery cell 20 may further include an electrode terminal 23, which is disposed on the housing 21, and the electrode terminal 23 is used to electrically connect to the tab of the electrode assembly 22 to input or output the electrical energy of the battery cell 20. The electrode terminal 23 may be disposed on the shell 211 of the housing 21, or may be disposed on the end cover 212 of the housing 21. The electrode terminal 23 may be directly connected to the tab, for example, the electrode terminal 23 is welded to the tab. The electrode terminal 23 may also be indirectly connected to the tab, for example, the electrode terminal 23 is indirectly connected to the tab through a current collecting member. The current collecting member may be a metal conductor, for example, copper, iron, aluminum, steel, aluminum alloy, etc.

[0151] As an example, Figure 3 and Figure 4 As shown, an opening 2111 is formed at one end of the shell 211, and there is one end cap 212 in the shell 21, and one end cap 212 closes one opening 2111 of the shell 211. Two electrode terminals 23 are provided on the end cap 212, and the two electrode terminals 23 are respectively a positive electrode terminal 23 and a negative electrode terminal 23. A positive electrode tab 2212 and a negative electrode tab 2222 are formed at one end of the electrode assembly 22 facing the end cap 212, and the positive electrode terminal 23 is electrically connected to the positive electrode tab 2212, and the negative electrode terminal 23 is electrically connected to the negative electrode tab 2222.

[0152] Please refer to Figure 4-Figure 7, the embodiment of the present application provides a battery cell 20, the electrode assembly 22 includes the electrode assembly 22 and the insulating member 24; the electrode assembly 22 includes a positive electrode sheet 221 and a negative electrode sheet 222, the positive electrode sheet 221 includes a positive electrode body 2211 and a positive electrode ear 2212, the negative electrode sheet 222 includes a negative electrode body 2221 and a negative electrode ear 2222, the positive electrode ear 2212 is connected to one end of the positive electrode body 2211 along a first direction X, along the first direction X, the end of the negative electrode body 2221 close to the positive electrode ear 2212 is a first end 22211, the negative electrode ear 2222 is connected to the first end 22211, the positive electrode body 2211 includes a positive electrode current collecting layer and a positive electrode active material layer 22112, the positive electrode ear 2212 is connected The positive electrode current collecting layer 22111 is connected to the positive electrode current collecting layer 22111, and a positive electrode active material layer 22112 is arranged on at least one side of the positive electrode current collecting layer along the thickness direction thereof; the insulating member 24 is arranged at one end of the positive electrode active material layer 22112 close to the positive electrode ear 2212 along the first direction X, and covers a part of the surface of the positive electrode current collecting layer 22111 facing the positive electrode active material layer 22112, and the insulating member 24 includes a first insulating portion 241 and a second insulating portion 242 arranged and connected along the first direction X, the first insulating portion 241 is arranged between the second insulating portion 242 and the positive electrode active material layer 22112, the thickness of the first insulating portion 241 is greater than the thickness of the second insulating portion 242, and the first insulating portion 241 exceeds the first end 22211 along the first direction X.

[0153] The positive current collecting layer 22111 is connected to the positive electrode tab 2212 to form a positive current collector of the positive electrode sheet 221. The positive current collecting layer 22111 and the positive electrode tab 2212 can be integrally formed, for example, by die-cutting the same current collector to form an integral positive current collecting layer and positive electrode tab 2212, which facilitates the manufacturing of the positive electrode sheet 221 and helps improve production efficiency.

[0154] The positive electrode current collecting layer 22111 and the positive electrode tab 2212 can also be split structures. For example, different current collectors are die-cut separately to form a split positive electrode current collecting layer 22111 and a positive electrode tab 2212, and then the positive electrode current collecting layer 22111 and the positive electrode tab 2212 are connected as a whole through conductive glue, welding and other connection methods to form a positive electrode collector of the positive electrode sheet 221, so that the structural setting of the positive electrode collector is more flexible.

[0155] In some embodiments, only one surface of the positive current collecting layer along its thickness direction is coated with the positive active material layer 22112. In other embodiments, both opposite surfaces of the positive current collecting layer along its thickness direction may be coated with the positive active material layer 22112.

[0156] The positive electrode active material layer 22112 may only cover a portion of the surface of the positive electrode current collecting layer along the thickness direction thereof. Exemplarily, the positive electrode current collecting layer includes a first region 221111 covered by the positive electrode active material layer 22112 and a second region 221112 not covered by the positive electrode active material layer 22112, the first region 221111 and the second region 221112 are arranged and connected along the first direction X, and the positive electrode tab 2212 is connected to one end of the second region 221112 away from the first region 221111. In the positive electrode current collecting layer including a first region 221111 covered by the positive electrode active material layer 22112 and a second region 221112 not covered by the positive electrode active material layer 22112, the first insulating portion 241 of the insulating member 24 may be provided on the surface of the second region 221112 along the thickness direction of the positive electrode current collecting layer 22111.

[0157] In the embodiment where the positive electrode active material is disposed on only one side of the first region 221111 along the thickness direction of the positive electrode current collecting layer, the second region 221112 is provided with an insulating member 24 at least close to the surface of the positive electrode active material layer 22112. In the embodiment where the positive electrode active material is disposed on both sides of the first region 221111 along the thickness direction of the positive electrode current collecting layer, the insulating member 24 may be disposed on both opposite surfaces of the second region 221112 along the thickness direction of the positive electrode current collecting layer.

[0158] In some embodiments, the insulating member 24 may be partially disposed in the second region 221112, and another portion of the insulating member 24 may be disposed in the positive electrode tab 2212. Figure 8 , Fig. 9 As shown, a portion of the first insulating portion 241 is disposed in the second region 221112, and another portion of the first insulating portion 241 and the second insulating portion 242 are disposed in the positive electrode tab 2212. Fig.10 As shown, along the width direction X' of the current collector 22111' (i.e., the width direction of the positive electrode sheet 221, corresponding to the first direction X), the positive electrode active material layer 22112 and the insulating member 24 are sequentially arranged, and the current collector 22111' forms a blank area on the side of the insulating member 24 away from the positive electrode active material layer 22112. The first insulating portion 241 of the insulating member 24 is arranged between the second insulating portion 242 and the positive electrode active material layer 22112. Fig.10 The dotted line path in the figure is die-cut to form the positive electrode ear 2212, and finally the positive electrode ear 2212 is formed. Figure 8 and Fig. 9The positive electrode tab 221 in the embodiment. Part of the die-cutting path is located at the first insulating portion 241 of the insulating member 24, so that after the die-cutting of the positive electrode tab 2212 is completed, along the width direction of the positive electrode tab 221, a part of the first insulating portion 241 of the insulating member 24 is located at the second region 221112 of the positive current collecting layer 22111 where the positive active material layer 22112 is not provided, and another part of the first insulating portion 241 and the second insulating portion 242 are both located at the positive electrode tab 2212 protruding from the second region 221112 away from the first region 221111.

[0159] like Fig.11 As shown, the first insulating portion 241 is disposed in the second region 221112, and the second insulating portion 242 is disposed in the positive electrode tab 2212. In this embodiment, when die-cutting the positive electrode tab 2212, die-cutting is performed along the boundary between the first insulating portion 241 and the second insulating portion 242. Alternatively, as Fig.12 As shown, a portion of the second insulating portion 242 and the first insulating portion 241 are disposed in the second region 221112, and another portion of the second insulating portion 242 is disposed in the positive electrode tab 2212. In this embodiment, when the positive electrode tab 2212 is formed by die cutting, the die cutting track is located in the second insulating portion 242.

[0160] like Fig.13 As shown, in other embodiments, the insulating member 24 may be completely disposed in the second region 221112. In this embodiment, when die-cutting to form the positive electrode tab 2212, die-cutting is performed along the edge of the second insulating portion 242 away from the first insulating portion 241.

[0161] For the wound electrode assembly 22 , the first direction X may be parallel to the extension direction of the winding axis of the wound electrode assembly 22 .

[0162] The negative electrode current collecting layer is connected to the negative electrode tab 2222 to form a negative electrode current collector of the negative electrode sheet 222. The negative electrode current collecting layer and the negative electrode tab 2222 can be integrally formed, for example, by die-cutting the same current collector to form an integral negative electrode current collecting layer and negative electrode tab 2222, which facilitates the manufacturing of the negative electrode sheet 222 and helps improve production efficiency.

[0163] The negative electrode current collecting layer and the negative electrode tab 2222 can also be separate structures. For example, different current collectors are die-cut separately to form separate negative electrode current collectors and negative electrode tabs 2222, and then the negative electrode current collecting layer and the negative electrode tab 2222 are connected as a whole through conductive glue, welding and other connection methods to form a negative electrode current collector of the negative electrode sheet 222, so that the structural setting of the negative electrode current collector is more flexible.

[0164] Only one surface of the negative electrode current collecting layer along its thickness direction is coated with the negative electrode active material layer. In other embodiments, both opposite surfaces of the negative electrode current collecting layer along its thickness direction may be coated with the negative electrode active material layer.

[0165] There are many ways to set the insulating member 24 on the positive electrode plate 221. For example, the insulating member 24 can be formed on the positive electrode plate 221 by coating, and the insulating member 24 is formed after the slurry solidifies; or the solid insulating member 24 can be bonded to the positive electrode plate 221.

[0166] In some embodiments, the insulating member 24 may be an integrally formed structure. In other embodiments, the insulating member 24 may also be formed by connecting a first insulating portion 241 and a second insulating portion 242 that are separated.

[0167] The thickness of the first insulating portion 241 and the thickness of the second insulating portion 242 are both the dimensions of the first insulating portion 241 along the stacking direction of the positive electrode current collecting layer 22111 and the insulating member 24. The first insulating portion 241 can be an equal thickness structure, or the first insulating portion 241 can be a non-equal thickness structure. In an embodiment in which the first insulating portion 241 is a non-equal thickness structure, the thickness of the first insulating portion 241 can be the maximum thickness of the first insulating portion 241. The second insulating portion 242 can be an equal thickness structure, or the second insulating portion 242 can be a non-equal thickness structure. In an embodiment in which the second insulating portion 242 is a non-equal thickness structure, the thickness of the second insulating portion 242 can be the maximum thickness of the second insulating portion 242.

[0168] In the first direction X, two opposite ends of the first insulating portion 241 may be connected to the positive electrode active material layer 22112 and the second insulating portion 242 , respectively.

[0169] The insulating member 24 includes a first insulating portion 241 and a second insulating portion 242 arranged and connected along the first direction X. The first insulating portion 241 is arranged between the second insulating portion 242 and the positive electrode active material layer 22112. The thickness of the first insulating portion 241 is greater than the thickness of the second insulating portion 242. The first insulating portion 241 exceeds the first end 22211 along the first direction X. The negative electrode tab 2222 is connected to the first end 22211 of the negative electrode body 2221. The first end 22211 can be considered as the die-cutting position of the negative electrode tab 2222, which is also the position where the burr is generated. The first insulating portion 241 with a larger thickness exceeds the first end 22211. 2211, the first insulating portion 241 can separate the first end 22211 and the positive electrode sheet 221, and the first insulating portion 241 can separate the negative electrode tab 2222 and the positive electrode sheet 221. The first insulating portion 241 has a greater thickness, which reduces the risk of the burr of the negative electrode tab 2222 piercing the insulating member 24 and the separator 223 at the same time. After the burr of the negative electrode tab 2222 pierces the separator 223, the first insulating portion 241 of the insulating member 24 can play the role of insulating separation between the negative electrode tab 2222 and the positive electrode sheet 221, thereby reducing the risk of short circuit of the battery cell 20 and improving the reliability of the battery cell 20. The second insulating portion 242 with a smaller thickness is arranged close to the positive electrode tab 2212, which can alleviate the problem of increasing the size of the electrode assembly 22 and thus causing energy density loss when the positive electrode tab 2212 is bent. Since the thickness of the second insulating portion 242 is relatively small, the size of the positive pole tab 2212 after bending is relatively small, so a smaller bending space of the positive pole tab 2212 can be reserved in the first direction X, for example, by increasing the width of the area corresponding to the positive active material layer 22112 of the positive electrode sheet 221, so that the space reserved for the bending of the positive pole tab 2212 in the shell 21 of the battery cell 20 in the first direction X is reduced, thereby improving the energy density of the battery cell. The thickness of the second insulating portion 242 is less than that of the first insulating portion 241, and can also reduce the risk of pole tab redundancy, thereby further reducing the risk of short circuit of the battery cell 20 and further improving the reliability of the battery cell 20.

[0170] like Figure 8 As shown, in some embodiments, the thickness of the first insulating portion 241 is D1, the thickness of the second insulating portion 242 is D2, and D1-D2≥20 μm.

[0171] Illustratively, D1-D2 may be 20 μm, 23 μm, 25 μm, 27 μm, 30 μm, 33 μm, 35 μm, 37 μm, 40 μm, etc.

[0172] D1-D2≥20μm, so that the thickness of the first insulating part 241 can be set larger, and the thickness of the second insulating part 242 is set smaller, reducing the risk of the burrs generated by the die-cutting of the negative electrode tab 2222 piercing the separator 223 and the insulating member 24 at the same time, thereby reducing the risk of short circuit of the battery cell 20 and improving the reliability of the battery cell 20. The smaller thickness of the second insulating part 242 can alleviate the problem of the increase in the size of the electrode assembly 22 when the positive electrode tab 2212 is bent, thereby causing the loss of energy density. Since the thickness of the second insulating part 242 is set smaller, the size of the positive electrode tab 2212 after bending is smaller, so that a smaller bending space of the positive electrode tab 2212 can be reserved in the first direction X, for example, by increasing the width of the corresponding area of ​​the positive active material layer 22112 of the positive electrode sheet 221, so that the space reserved for the bending of the positive electrode tab 2212 in the first direction X is reduced, thereby improving the energy density of the battery cell. The smaller thickness of the second insulating portion 242 can also reduce the risk of tab redundancy, thereby further reducing the risk of short circuit of the battery cell 20 and further improving the reliability of the battery cell 20 .

[0173] In some embodiments, the first insulating portion 241 has a thickness D1, 30 μm≤D1≤80 μm.

[0174] Illustratively, D1 may be 30 μm, 35 μm, 40 μm, 45 μm, 50 μm, 55 μm, 60 μm, 65 μm, 70 μm, 75 μm, 80 μm, etc.

[0175] 30μm≤D1, so that the thickness of the first insulating portion 241 is relatively large, reducing the risk of burrs generated by die-cutting the negative electrode tab 2222 piercing the first insulating portion 241, thereby reducing the risk of short circuit of the battery cell 20 and improving the reliability of the battery cell 20. D1≤80μm, the problem of the battery cell 20 having a reduced energy density due to the provision of the insulating member 24 is alleviated, so that the battery cell 20 has higher reliability and higher energy density.

[0176] In some embodiments, the second insulating portion 242 has a thickness D2, 10 μm≤D2≤60 μm.

[0177] Illustratively, D2 may be 10 μm, 15 μm, 20 μm, 25 μm, 30 μm, 35 μm, 40 μm, 45 μm, 50 μm, 55 μm, 60 μm, etc.

[0178] 10μm≤D2, so that the thickness of the second insulating part 242 is large enough, not only so that the second insulating part 242 can play a good insulating role between the positive electrode sheet 221 and the negative electrode sheet 222, but also reduce the risk of burrs generated when die-cutting the negative electrode tab 2222 piercing the second insulating part 242, thereby reducing the risk of short circuit of the battery cell 20, which is conducive to improving the reliability of the battery cell 20. D2≤60μm, reduce the influence of the insulating member 24 provided on the battery cell 20 on the energy density of the battery cell 20, so that the battery cell 20 has higher reliability and higher energy density.

[0179] like Figure 8 , Fig.10 , Fig.11 As shown, in some embodiments, along the thickness direction of the positive electrode tab 2212 , the positive electrode tab 2212 has a first surface 22121 , and the second insulating portion 242 covers a portion of the first surface 22121 .

[0180] The first surface 22121 includes a first area 22121a and a second area 22121b connected along the first direction X. The first area 22121a is closer to the positive electrode body 2211 than the second area 22121b, and the second insulating portion 242 covers the first area 22121a. The area of ​​the positive electrode tab 2212 not covered by the second insulating portion 242 can be connected to other structures inside the battery cell 20, such as a current collecting member.

[0181] like Figure 8 , Fig.11 As shown, the second insulating portion 242 may only cover a portion of the first surface 22121. Fig.12 As shown, the second insulating portion 242 may cover both a portion of the first surface 22121 of the positive electrode tab 2212 and a portion of the surface of the second region 221112 .

[0182] In an embodiment where the second insulating portion 242 covers a portion of the first surface 22121, as shown in FIG. Figure 8 As shown, the first insulating portion 241 may cover both the surface of the second region 221112 and a portion of the first surface 22121; Fig.11 As shown, the first insulating portion 241 may also only cover the surface of the second region 221112 .

[0183] The second insulating portion 242 covers a portion of the first surface 22121 of the positive electrode tab 2212. The second insulating portion 242 can insulate and separate the positive electrode tab 2212 and the negative electrode tab 222. The second insulating portion 242 can form a double insulation separation with the separator 223 between the positive electrode tab 2212 and the negative electrode tab 222, further reducing the risk of short circuit of the battery cell 20 and improving the reliability of the battery cell 20. After the separator 223 is punctured, the second insulating portion 242 can continue to play the role of insulating and separating the positive electrode tab 2212 and the negative electrode tab 222, which is conducive to reducing the risk of short circuit of the battery cell 20 after the burr of the positive electrode tab 2212 punctures the separator 223, and improving the reliability of the battery cell 20. In addition, the second insulating portion 242 has a small thickness, which is also convenient for the positive electrode tab 2212 to bend, thereby reducing the size of the electrode assembly 22 in the first direction X.

[0184] like Figure 8 As shown, in some embodiments, the first insulating portion 241 covers a portion of the first surface 22121. It can be understood that the first insulating portion 241 not only completely covers a surface of the second region 221112 in the thickness direction of the current collector, but also covers a portion of the first surface 22121 of the positive electrode tab 2212, so that the first insulating portion 241 with a larger thickness covers a larger area, which can further reduce the risk of the burrs generated by the die-cutting of the negative electrode tab 2222 piercing the separator 223 and the insulating member 24 at the same time, causing the battery cell 20 to short-circuit.

[0185] In the embodiment where the first insulating portion 241 covers a portion of the first surface 22121 , the second insulating portion 242 covers a portion of the first surface 22121 .

[0186] The first insulating portion 241 covers a portion of the first surface 22121, and the first insulating portion 241 can cover the positive electrode tab 2212, so that the first insulating portion 241 can insulate and separate the negative electrode tab 222 and the positive electrode tab 2212. The first insulating portion 241 can form a double insulation separation with the separator 223 between the positive electrode tab 2212 and the negative electrode tab 222, further reducing the risk of short circuit of the battery cell 20 and improving the reliability of the battery cell 20. After the burrs generated by die-cutting the negative electrode tab 2222 pierce the separator 223, the first insulating portion 241 can continue to play an insulating and separating role between the negative electrode tab 222 and the positive electrode tab 2212, reducing the risk of short circuit of the battery cell 20 and improving the reliability of the battery cell 20.

[0187] like Figure 8 , Figure 11-13As shown, in some embodiments, the positive electrode current collecting layer includes a first region 221111 covered by the positive electrode active material layer 22112 and a second region 221112 not covered by the positive electrode active material layer 22112, the first region 221111 and the second region 221112 are arranged and connected along a first direction X, the positive electrode ear 2212 is connected to one end of the second region 221112 away from the first region 221111, and the insulating member 24 covers the second region 221112.

[0188] The second region 221112 is the empty foil region of the positive electrode current collecting layer 22111. The insulating member 24 covers the second region 221112, which means that the surface of the second region 221112 in the thickness direction of the positive electrode current collecting layer 22111 is completely covered by the insulating member 24.

[0189] The insulating member 24 covers the second region 221112. The surface of the second region 221112 in the thickness direction of the positive electrode current collecting layer 22111 can be completely covered by the first insulating part 241, or the surface of the second region 221112 in the thickness direction of the positive electrode current collecting layer 22111 is completely covered by both the first insulating part 241 and the second insulating part 242. Figure 8 , Fig.11 , the surface of the second region 221112 in the thickness direction of the positive electrode current collecting layer 22111 is completely covered by the first insulating portion 241 . Fig.12 , Fig.13 Graph 2 shows a situation where the surface of the second region 221112 in the thickness direction of the positive electrode current collecting layer 22111 is completely covered by both the first insulating portion 241 and the second insulating portion 242 .

[0190] The positive electrode current collecting layer includes a first region 221111 covered by the positive electrode active material layer 22112 and a second region 221112 not covered by the positive electrode active material layer 22112. The first region 221111 and the second region 221112 are arranged and connected along the first direction X. The positive electrode ear is connected to the end of the second region 221112 away from the first region 221111, which is convenient for die-cutting to form the positive electrode ear 2212. The second region 221112 provides an installation position for the insulating member 24. The insulating member 24 covers the second region 221112 and can form a double insulating separation effect between the negative electrode plate 222 and the positive electrode plate 221 together with the isolation film 223, further reducing the risk of short circuit of the battery cell 20 and improving the reliability of the battery cell 20. After the burrs generated by die-cutting the negative electrode tab 2222 pierce the isolation membrane 223, the insulating member 24 can continue to play the role of insulation and separation, which is beneficial to reduce the risk of short circuit of the battery cell 20 and improve the reliability of the battery cell.

[0191] like Figure 8 , Figure 11-13As shown, in some embodiments, along the first direction X, the size of the second region 221112 is H1, 1mm≤H1≤5mm.

[0192] Illustratively, H1 may be 1 mm, 1.5 mm, 2 mm, 2.5 mm, 3 mm, 3.5 mm, 4 mm, 4.5 mm, 5 mm, etc.

[0193] 1mm≤H1 allows sufficient distance between the positive electrode active material layer 22112 and the die-cutting position of the positive electrode tab 2212, reducing the risk of damaging the positive electrode active material layer 22112 during die-cutting. H1≤5mm controls the size of the second region 221112, alleviating the problem of energy density loss of the battery cell 20 caused by the second region 221112 without the positive electrode active material layer 22112.

[0194] Furthermore, 2mm≤H1≤3mm.

[0195] Illustratively, H1 may be 2 mm, 2.1 mm, 2.2 mm, 2.3 mm, 2.4 mm, 2.5 mm, 2.6 mm, 2.7 mm, 2.8 mm, 2.9 mm, 3 mm, etc.

[0196] 2mm≤H1 makes the distance between the positive electrode active material layer 22112 and the die-cutting position of the positive electrode tab 2212 larger, further reducing the risk of damaging the positive electrode active material layer 22112 during die-cutting. H1≤3mm further alleviates the problem of the second area 221112 without the positive electrode active material layer 22112 causing the battery cell 20 to lose energy density.

[0197] like Fig.14 As shown, in some embodiments, the first insulating portion 241 includes a first part 2411 and a second part 2412, the first part 2411 and the second part 2412 are stacked along the thickness direction Y of the positive electrode sheet, the second part 2412 is connected to the surface of the first part 2411 away from the positive electrode current collecting layer, and the first part 2411 connects the positive electrode active material layer 22112 and the second insulating portion 242.

[0198] Along the thickness direction Y of the positive electrode sheet, the first portion 2411 is located between the positive current collecting layer and the second portion 2412. The first portion 2411 may be directly connected to the positive current collecting layer 22111 or indirectly connected. Along the first direction X, the two ends of the first portion 2411 are respectively connected to the positive active material layer 22112 and the second insulating portion 242.

[0199] The first part 2411 and the second part 2412 can be arranged in steps on the positive electrode sheet 221. Taking the insulating member 24 formed on the positive electrode sheet 221 by coating slurry as an example, the slurry can be coated for the first time in the second area 221112, and the first part 2411 is formed after solidification, and then the slurry is coated for the second time on the surface of the first part 2411 away from the positive current collecting layer 22111, and the second part 2412 is formed after solidification, so that the thickness of each slurry coating can be smaller, which reduces the difficulty of coating and makes it easier to ensure the quality of each coating.

[0200] The thickness of the first part 2411 and the thickness of the second part 2412 may be the same or different. The thickness of the first part 2411 is the distance between the two surfaces of the first part 2411 that are farthest together along the thickness direction Y of the positive electrode sheet. The thickness of the second part 2412 is the distance between the two surfaces of the second part 2412 that are farthest together along the thickness direction Y of the positive electrode sheet.

[0201] The first insulating part 241 includes a first part 2411 and a second part 2412 which are stacked along the thickness direction Y of the positive electrode plate. When manufacturing the insulating part 24, the first part 2411 and the second part 2412 with smaller thickness can be manufactured in steps. The first part 2411 and the second part 2412 together form the first insulating part 241 with larger thickness, which facilitates the manufacturing and molding of the first insulating part 241.

[0202] like Fig.14 As shown, in some embodiments, the first portion 2411 and the second insulating portion 242 have the same thickness.

[0203] Along the thickness direction Y of the positive electrode sheet, the surface of the first portion 2411 away from the positive current collecting layer 22111 is flush with the surface of the second insulating portion 242 away from the positive current collecting layer, and the surface of the first portion 2411 close to the positive current collecting layer 22111 is flush with the surface of the second insulating portion 242 close to the positive current collecting layer. Taking the insulating member 24 formed on the positive electrode sheet 221 by coating slurry as an example, since the first portion 2411 and the second insulating portion 242 have the same thickness, the first portion 2411 and the second insulating portion 242 can be formed by one coating.

[0204] The first portion 2411 and the second insulating portion 242 have the same thickness, which facilitates the connection between the first portion 2411 and the second insulating portion 242 and the manufacture of the insulating member 24 .

[0205] In some embodiments, the first portion 2411 and the second insulating portion 242 are integrally formed.

[0206] It is understandable that the first portion 2411 and the second insulating portion 242 are formed by an integral molding method, such as injection molding, coating, etc. Exemplarily, in an embodiment where the first portion 2411 and the second insulating portion 242 have the same thickness, the first portion 2411 and the second insulating portion 242 can be formed by one coating.

[0207] The first portion 2411 and the second insulating portion 242 are integrally formed, which facilitates the manufacture of the insulating member 24 .

[0208] In some embodiments, the first portion 2411 and the second portion 2412 are made of the same material.

[0209] Exemplarily, the materials of the first part 2411 and the second part 2412 can both be ceramic, rubber, silicone, etc.

[0210] The first portion 2411 and the second portion 2412 are made of the same material, which facilitates a stable connection between the first portion 2411 and the second portion 2412 and facilitates the manufacture of the insulating member 24 .

[0211] In other embodiments, the first portion 2411 and the second portion 2412 are made of different materials.

[0212] Exemplarily, the material of the first part 2411 is ceramic, and the material of the second part 2412 is rubber; the material of the first part 2411 is rubber, and the material of the second part 2412 is ceramic.

[0213] The first part 2411 and the second part 2412 are made of different materials, which facilitates the selection of appropriate materials for the first part 2411 and the second part 2412 respectively, so that the overall structural performance formed by the insulating member 24 and the positive electrode plate 221 is better.

[0214] In some embodiments, the first portion 2411 and the second insulating portion 242 are made of the same material.

[0215] Exemplarily, the materials of the first portion 2411 and the second insulating portion 242 may both be ceramic, rubber, silicone, etc.

[0216] The first portion 2411 and the second insulating portion 242 are made of the same material, which facilitates the manufacturing of the insulating member 24 .

[0217] In some other embodiments, the first portion 2411 and the second insulating portion 242 are made of different materials.

[0218] Exemplarily, the first part 2411 is made of ceramic, and the second insulating part 242 is made of rubber; the first part 2411 is made of rubber, and the second insulating part 242 is made of ceramic.

[0219] The first portion 2411 and the second insulating portion 242 are made of different materials, which facilitates the selection of appropriate materials for the first portion 2411 and the second insulating portion 242 , so that the overall structural performance formed by the insulating member 24 and the positive electrode plate 221 is better.

[0220] like Fig.15 As shown, in other embodiments, the first insulating part 241 includes a first part 2411 and a second part 2412, the positive electrode active material layer 22112 and the positive electrode current collecting layer are both connected to the first part 2411, and a first accommodating part 2413 is provided on the surface of the first part 2411 facing the positive electrode current collecting layer, and the second part 2412 is accommodated in the first accommodating part 2413 and connected to the second insulating part 242.

[0221] One end of the first portion 2411 located in the first direction X is connected to the positive electrode active material layer 22112. The surface of the first portion 2411 facing the positive electrode current collecting layer in the thickness direction Y of the positive electrode sheet is connected to the positive electrode current collecting layer.

[0222] The surface of the positive electrode sheet of the first portion 2411 facing the positive electrode current collecting layer in the thickness direction Y may be directly connected to the positive electrode current collecting layer or may be indirectly connected to the positive electrode current collecting layer. Fig.15 The vertical dotted line in the middle is the boundary between the second portion 2412 and the second insulating portion 242 .

[0223] The first accommodating portion 2413 is recessed from the surface of the first portion 2411 facing the positive electrode current collecting layer in the thickness direction Y of the positive electrode sheet in the direction away from the positive electrode current collecting layer, and extends along the first direction X to the surface of the first portion 2411 away from the positive electrode active material layer 22112. The second portion 2412 is accommodated in the first accommodating portion 2413, and the thickness of the second portion 2412 can be the same as the depth of the first accommodating portion 2413 along the thickness direction Y of the positive electrode sheet, and the size of the second portion 2412 along the first direction X can be the same as the size of the first accommodating portion 2413 along the first direction X, so that the second portion 2412 completely fills the first accommodating portion 2413, and the second portion 2412 can support the first portion 2411, reducing the risk of collapse of the first portion 2411.

[0224] The first insulating portion 241 includes a first part 2411 and a second part 2412. When manufacturing the insulating member 24, the first part 2411 and the second part 2412 can be manufactured in steps. The first part 2411 and the second part 2412 together form the first insulating portion 241 with a relatively large thickness, which facilitates the manufacturing and molding of the first insulating portion 241. When the second insulating portion 242 and the second part 2412 are integrally formed, the second part 2412 is accommodated in the first accommodating portion 2413 and connected to the second insulating portion 242, which is equivalent to increasing the connection area between the first insulating portion 241 and the second insulating portion 242, so that the connection between the first insulating portion 241 and the second insulating portion 242 is more stable.

[0225] In some embodiments, along the thickness direction of the first insulating portion 241, the distance between the surface of the positive electrode active material layer 22112 facing away from the positive electrode current collecting layer and the positive electrode current collecting layer is not less than the distance between the surface of the first insulating portion 241 facing away from the positive electrode current collecting layer and the positive electrode current collecting layer. In this way, the insulating member 24 will not increase the spacing between the positive electrode plate 221 and the negative electrode plate 222, which is beneficial for the battery cell 20 to have better cycle performance, and also enables the insulating member 24 to make full use of the space between the positive electrode plate 221 and the negative electrode plate 222. The insulating member 24 occupies a smaller space, which is beneficial for the battery cell 20 to have better energy density.

[0226] For example, Figure 8 , Figure 11-Figure 14 As shown, along the thickness direction of the first insulating portion 241 , the surface of the positive electrode active material layer 22112 facing away from the positive electrode current collecting layer is farther away from the positive electrode current collecting layer than the surface of the first insulating portion 241 facing away from the positive electrode current collecting layer.

[0227] The surface of the positive electrode active material layer 22112 facing away from the positive electrode current collecting layer is farther away from the positive electrode current collecting layer than the surface of the first insulating portion 241 facing away from the positive electrode current collecting layer, so as to prevent the insulating member 24 from increasing the distance between the positive electrode pole piece 221 and the negative electrode pole piece 222, which is beneficial for the battery cell 20 to have better cycle performance. The surface of the positive electrode active material layer 22112 facing away from the positive electrode current collecting layer is farther away from the positive electrode current collecting layer than the surface of the first insulating portion 241 facing away from the positive electrode current collecting layer, which can also make the insulating member 24 fully utilize the space between the positive electrode pole piece 221 and the negative electrode pole piece 222, and the insulating member 24 occupies a smaller space, which is beneficial for the battery cell 20 to have better energy density.

[0228] In other embodiments, along the thickness direction of the first insulating part 241, the surface of the positive electrode active material layer 22112 away from the positive electrode current collecting layer can be flush with the surface of the first insulating part 241 away from the positive electrode current collecting layer, so as to achieve that along the thickness direction of the first insulating part 241, the distance between the surface of the positive electrode active material layer 22112 away from the positive electrode current collecting layer and the positive electrode current collecting layer is not less than the distance between the surface of the first insulating part 241 away from the positive electrode current collecting layer and the positive electrode current collecting layer. In this way, the thickness of the first insulating part 241 can be made larger, further reducing the risk of puncture by burrs.

[0229] like Fig.16 , Fig.17 As shown, in some embodiments, the positive electrode sheet 221 further includes an adhesive layer 2213, which is disposed between the positive electrode active material layer 22112 and the positive electrode current collecting layer, and connects the positive electrode active material layer 22112 and the positive electrode current collecting layer.

[0230] The two opposite surfaces of the adhesive layer 2213 along the thickness direction of the positive electrode sheet 221 are respectively connected to the positive current collecting layer and the positive active material layer 22112. The positive active material layer 22112 and the positive current collecting layer are indirectly connected through the adhesive layer 2213.

[0231] The bonding layer 2213 is connected between the positive electrode active material layer 22112 and the positive electrode current collecting layer, so that the connection stability between the positive electrode active material layer 22112 and the positive electrode current collecting layer 22111 can be improved, and the strength of the positive electrode sheet 221 can also be improved.

[0232] In some embodiments, the positive electrode current collecting layer includes a first region 221111 covered by the positive electrode active material layer 22112 and a second region 221112 not covered by the positive electrode active material layer 22112, the first region 221111 and the second region 221112 are arranged and connected along a first direction X, the first pole ear is connected to one end of the second region 221112 away from the first region 221111, and the insulating member 24 covers the second region 221112; along the first direction X, the bonding layer 2213 includes a protruding portion 22131 that protrudes beyond one end of the positive electrode active material layer 22112 close to the insulating member 24, and the protruding portion 22131 covers at least a portion of the second region 221112.

[0233] Along the first direction X, the adhesive layer 2213 extends beyond the end of the positive electrode active material layer 22112 facing the insulating member 24 to form a protruding portion 22131. Along the first direction X, the size of the protruding portion 22131 may be smaller than the size of the second region 221112, so that the protruding portion 22131 covers at least a portion of the second region 221112. In the embodiment where the protruding portion 22131 covers a portion of the second region 221112 along the first direction X, along the first direction X, a portion of the insulating member 24 is indirectly connected to the positive electrode current collecting layer through the protruding portion 22131, a portion of the insulating member 24 is indirectly connected to the positive electrode current collecting layer through the protruding portion 22131, a portion of the protruding portion 22131 is directly connected to the positive electrode current collecting layer, and a portion of the protruding portion 22131 is directly connected to the positive electrode tab 2212.

[0234] Along the first direction X, the size of the protruding portion 22131 and the size of the second region 221112 may be the same, so that the protruding portion 22131 covers the entire second region 221112 along the first direction X. In an embodiment where the protruding portion covers the entire second region 221112 along the first direction X, a portion of the protruding portion 22131 is indirectly connected to the positive electrode current collecting layer through the protruding portion 22131, and another portion of the protruding portion 22131 is directly connected to the positive electrode tab 2212.

[0235] The size of the protruding portion 22131 along the first direction X can be designed according to the actual product. For example, along the first direction X, the size of the protruding portion 22131 is H2, 0.5 mm ≤ H2 ≤ 1 mm. For example, H2 can be 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1 mm, etc.

[0236] The bonding layer 2213 includes a protruding portion 22131 that protrudes beyond one end of the positive electrode active material layer 22112 close to the insulating member 24, and the protruding portion 22131 covers at least a portion of the second region 221112 that is not covered by the positive electrode active material layer 22112, thereby increasing the coverage area of ​​the bonding layer 2213 on the positive electrode current collecting layer, which is beneficial to improving the strength of the positive electrode sheet 221. The bonding layer 2213 has the protruding portion 22131, and the insulating member 24 and the second region 221112 can be connected through the protruding portion 22131 of the bonding layer 2213, which is beneficial to improving the connection stability of the insulating member 24.

[0237] In some embodiments, the first insulating portion 241 is connected to the protruding portion 22131 .

[0238] It can be understood that at least a portion of the first insulating portion 241 along the first direction X is connected to the protruding portion 22131 .

[0239] The first insulating portion 241 is connected to the protruding portion 22131 , which is beneficial to improving the bonding stability between the insulating member 24 and the positive electrode current collecting layer.

[0240] like Fig.16 As shown, in some embodiments, the first insulating portion 241 has a second accommodating portion 2414 , and the protruding portion 22131 is accommodated in the second accommodating portion 2414 and connected to the first insulating portion 241 .

[0241] The second receiving portion 2414 is provided on the surface of the first insulating portion 241 facing the positive current collecting layer and is recessed in a direction away from the positive current collecting layer, and extends along the first direction X to the surface of the first insulating portion 241 facing the positive active material layer 22112 .

[0242] The protruding portion 22131 is accommodated in the second accommodating portion 2414 of the first insulating portion 241 and connected to the first insulating portion 241, so that the connection area between the insulating member 24 and the adhesive layer 2213 is larger, the bonding stability is better, and it is also beneficial to reduce the volume of the overall structure formed by the positive electrode sheet 221 and the insulating member 24.

[0243] like Fig.16 , Fig.17 As shown, in some embodiments, the thickness of the adhesive layer 2213 is less than or equal to the thickness of the second insulating portion 242 .

[0244] The thickness of the second insulating portion 242 is D2, the thickness of the adhesive layer 2213 is D6, and D6≤D2.

[0245] The thickness of the adhesive layer 2213 is less than or equal to the thickness of the second insulating portion 242 . The adhesive layer 2213 can be made small enough to alleviate the problem of reducing the energy density of the battery cell 20 due to the provision of the adhesive layer 2213 .

[0246] The material of the adhesive layer 2213 needs to have good adhesive properties and conductive properties. In some embodiments, the adhesive layer 2213 includes a carbon coating.

[0247] The bonding layer 2213 includes a carbon coating, which can not only increase the bonding performance between the positive electrode current collecting layer and the positive electrode active material layer 22112 , but also enhance the conductivity between the positive electrode current collecting layer and the positive electrode active material layer 22112 .

[0248] In some embodiments, along the first direction X, the width of the positive electrode active material layer 22112 is D3, the width of the adhesive layer 2213 is D4, and 0.1 mm≤D4-D3≤5 mm.

[0249] In an embodiment where one end of the positive electrode active material layer 22112 away from the positive electrode tab 2212 is flush with one end of the bonding layer 2213 away from the positive electrode tab 2212 , D4 - D3 is the dimension of the protruding portion 22131 along the first direction X, that is, D4 - D3 = H2.

[0250] Exemplarily, D4-D3 may be 0.1 mm, 0.5 mm, 1 mm, 2 mm, 2.5 mm, 3 mm, 3.5 mm, 4 mm, 4.5 mm, 5 mm, etc.

[0251] 0.1mm≤D4-D3 increases the coverage area of ​​the adhesive layer 2213 on the current collector, which is beneficial to enhancing the strength of the positive electrode sheet 221. D4-D3≤5mm reduces the space occupied by the adhesive layer 2213 and alleviates the problem of energy density loss of the battery cell 20 due to the provision of the adhesive layer 2213.

[0252] In some embodiments, 0.5 mm ≤ D4 - D3 ≤ 1 mm.

[0253] Illustratively, D4-D3 may be 0.5 mm, 0.55 mm, 0.6 mm, 0.65 mm, 0.7 mm, 0.75 mm, 0.8 mm, 0.85 mm, 0.9 mm, 0.95 mm, etc.

[0254] 0.5mm≤D4-D3 further increases the coverage area of ​​the adhesive layer 2213 on the current collector, which is beneficial to further enhance the strength of the positive electrode sheet 221. D4-D3≤1mm further reduces the space occupied by the adhesive layer 2213, thereby further alleviating the problem of energy density loss of the battery cell 20 due to the provision of the adhesive layer 2213.

[0255] The embodiment of the present application further provides a battery device 100 , and the battery device 100 includes the battery cell 20 provided in any of the above embodiments.

[0256] The battery cell 20 has good reliability, and the battery device 100 including the battery cell 20 has good reliability.

[0257] The embodiment of the present application further provides an electrical device, which includes the battery cell 20 provided by any of the above embodiments or the battery device 100 provided by the above embodiments.

[0258] The battery cell 20 and the battery device 100 are used to provide electric energy to the electric device. The electric device can be powered by the battery cell 20 or by the electric device.

[0259] The battery cell 20 and the battery device 100 described above have good reliability, which is beneficial to improving the reliability of power consumption of the power-consuming device powered by the battery cell 20 and the power-consuming device.

[0260] The present application provides a battery cell 20, which includes an electrode assembly 22, an insulating member 24 and an adhesive layer 2213; the electrode assembly 22 includes a positive electrode sheet 221 and a negative electrode sheet 222, the positive electrode sheet 221 includes a positive electrode body 2211 and a positive electrode tab 2212, the negative electrode sheet 222 includes a negative electrode body 2221 and a negative electrode tab 2222, the positive electrode tab 2212 is connected to the positive electrode body 2211 along a first direction X end, along the first direction X, the end of the negative electrode body 2221 close to the positive electrode ear 2212 is the first end 22211, the negative electrode ear 2222 is connected to the first end 22211, the positive electrode body 2211 includes a positive electrode current collecting layer and a positive electrode active material layer 22112, the positive electrode ear 2212 is connected to the positive electrode current collecting layer 22111, along the first direction X, the positive electrode current collecting layer 22111 includes a first region 221 provided with a positive electrode active material layer 22112 111 and a second region 221112 where the positive electrode active material layer 22112 is not provided; the insulating member 24 is provided at one end of the positive electrode active material layer 22112 close to the positive electrode tab 2212 along the first direction X, and covers a portion of the surface of the positive electrode current collecting layer 22111 facing the positive electrode active material layer 22112, the insulating member 24 includes a first insulating portion 241 and a second insulating portion 242 arranged and connected along the first direction X, the first insulating portion 241 is connected between the second insulating portion 242 and the positive electrode active material layer 22112, the first insulating portion 241 covers the surface of the second region 221112 and a portion of the surface of the positive electrode tab 2212 in its thickness direction, the second insulating portion 242 covers a portion of the surface of the positive electrode tab 2212 in its thickness direction, the thickness of the first insulating portion 241 is greater than the thickness of the second insulating portion 242, and the first insulating portion 241 exceeds the first end 22211 along the first direction X. The first insulating portion 241 includes a first portion 2411 and a second portion 2412, which are stacked along the thickness direction Y of the positive electrode sheet; the first portion 2411 is arranged close to the positive current collecting layer, and the second portion 2412 is arranged on the surface of the first portion 2411 away from the positive current collecting layer 22111. The adhesive layer 2213 is arranged between the positive active material layer 22112 and the positive current collecting layer 22111, and along the first direction X, the adhesive layer 2213 has a protruding portion 22131 that protrudes from one end of the positive active material layer 22112 close to the positive electrode tab 2212. The first portion 2411 has a second accommodating portion 2414, and the protruding portion 22131 is accommodated in the second accommodating portion 2414. Alternatively, the first insulating portion 241 includes a first part 2411 and a second part 2412 , the first part 2411 has a first accommodation portion 2413 on a surface facing the positive electrode current collecting layer, the second part 2412 is accommodated in the first accommodation portion 2413 , and the second insulating portion 242 is connected to the second part 2412 .The bonding layer 2213 is disposed between the positive electrode active material layer 22112 and the positive electrode current collecting layer 22111. Along the first direction X, the bonding layer 2213 has a protruding portion 22131 that protrudes beyond the positive electrode active material layer 22112 and is close to one end of the positive electrode tab 2212. The surface of the first portion 2411 facing the positive electrode current collecting layer has a second accommodating portion 2414, and the protruding portion 22131 is accommodated in the second accommodating portion 2414.

[0261] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application may be combined with each other.

[0262] The above embodiments are only used to illustrate the technical solution of the present application and are not used to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A battery cell, characterized in that: include: An electrode assembly, comprising a positive electrode sheet and a negative electrode sheet, wherein the positive electrode sheet comprises a positive electrode body and a positive electrode tab, and the negative electrode sheet comprises a negative electrode body and a negative electrode tab, wherein the positive electrode tab is connected to one end of the positive electrode body along a first direction, wherein an end of the negative electrode body close to the positive electrode tab along the first direction is a first end, and the negative electrode tab is connected to the first end, wherein the positive electrode body comprises a positive current collecting layer and a positive active material layer, wherein the positive electrode tab is connected to the positive current collecting layer, and wherein the positive active material layer is provided on at least one side of the positive current collecting layer along the thickness direction thereof; An insulating member is arranged along the first direction at one end of the positive electrode active material layer close to the positive electrode tab, and covers a portion of the surface of the positive electrode current collector facing the positive electrode active material layer, the insulating member includes a first insulating portion and a second insulating portion arranged and connected along the first direction, the first insulating portion is arranged between the second insulating portion and the positive electrode active material layer, the thickness of the first insulating portion is greater than the thickness of the second insulating portion, and the first insulating portion extends beyond the first end along the first direction.

2. The battery cell according to claim 1, characterized in that: The thickness of the first insulating portion is D1, the thickness of the second insulating portion is D2, and D1-D2≥20 μm.

3. The battery cell according to claim 1, characterized in that: The thickness of the first insulating portion is D1, 30 μm≤D1≤80 μm.

4. The battery cell according to claim 1, characterized in that: The thickness of the second insulating portion is D2, 10 μm≤D2≤60 μm.

5. The battery cell according to claim 1, characterized in that: The positive electrode tab has a first surface along a thickness direction of the positive electrode tab, and the second insulating portion covers a portion of the first surface.

6. The battery cell according to claim 5, characterized in that: The first insulating portion covers a portion of the first surface.

7. The battery cell according to claim 1, characterized in that: The positive electrode current collecting layer includes a first region covered by the positive electrode active material layer and a second region not covered by the positive electrode active material layer, the first region and the second region are arranged and connected along the first direction, the positive electrode tab is connected to an end of the second region away from the first region, and the insulating member covers the second region.

8. The battery cell according to claim 7, characterized in that: Along the first direction, a size of the second area is H1, 1 mm ≤ H1 ≤ 5 mm.

9. The battery cell according to claim 8, characterized in that: 2mm≤H1≤3mm.

10. The battery cell according to claim 1, characterized in that: The first insulating portion includes a first part and a second part, the first part and the second part are stacked along the thickness direction of the positive electrode sheet, the second part is connected to the surface of the first part away from the positive electrode current collecting layer, and the first part connects the positive electrode active material layer and the second insulating portion.

11. The battery cell according to claim 10, characterized in that: The first portion and the second insulating portion have the same thickness.

12. The battery cell according to claim 10, characterized in that: The first portion and the second insulating portion are integrally formed.

13. The battery cell according to claim 10, characterized in that: The first part and the second part are made of the same material.

14. The battery cell according to claim 10, characterized in that: The first part and the second part are made of different materials.

15. The battery cell according to claim 10, characterized in that: The first portion and the second insulating portion are made of the same material.

16. The battery cell according to claim 10, characterized in that: The first portion and the second insulating portion are made of different materials.

17. The battery cell according to claim 1, characterized in that: The first insulating part includes a first portion and a second portion, the positive electrode active material layer and the positive electrode current collecting layer are both connected to the first portion, a first accommodating portion is provided on the surface of the first portion facing the positive electrode current collecting layer, and the second portion is accommodated in the first accommodating portion and connected to the second insulating part.

18. The battery cell according to claim 1, characterized in that: Along the thickness direction of the first insulating portion, a surface of the positive electrode active material layer facing away from the positive electrode current collecting layer is farther away from the positive electrode current collecting layer than a surface of the first insulating portion facing away from the positive electrode current collecting layer.

19. The battery cell according to any one of claims 1 to 18, characterized in that: The positive electrode sheet further includes an adhesive layer, which is disposed between the positive electrode active material layer and the positive electrode current collecting layer and connects the positive electrode active material layer and the positive electrode current collecting layer.

20. The battery cell according to claim 19, characterized in that The positive electrode current collecting layer comprises a first region covered by the positive electrode active material layer and a second region not covered by the positive electrode active material layer, the first region and the second region are arranged and connected along the first direction, the positive electrode tab is connected to an end of the second region away from the first region, and the insulating member covers the second region; Along the first direction, the adhesive layer includes a protruding portion that protrudes beyond one end of the positive electrode active material layer close to the insulating member, and the protruding portion covers at least a portion of the second region.

21. The battery cell according to claim 20, characterized in that The first insulating portion is connected to the protruding portion.

22. The battery cell according to claim 20, characterized in that The first insulating portion has a second accommodation portion, and the protruding portion is accommodated in the second accommodation portion and connected to the first insulating portion.

23. The battery cell according to claim 19, characterized in that The thickness of the adhesive layer is less than or equal to the thickness of the second insulating portion.

24. The battery cell according to claim 19, characterized in that: The bonding layer includes a carbon coating.

25. The battery cell according to claim 19, characterized in that: Along the first direction, the width of the positive electrode active material layer is D3, the width of the adhesive layer is D4, and 0.1 mm≤D4-D3≤5 mm.

26. The battery cell according to claim 25, characterized in that 0.5mm≤D4-D3≤1mm.

27. A battery device, characterized in that: Comprising a battery cell as claimed in any one of claims 1 to 26.

28. An electrical device, characterized in that: Comprising the battery cell according to any one of claims 1 to 26 or the battery device according to claim 27.

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