Battery monomer, battery pack and power utilization device
By forming tab grooves in the separator to avoid the tabs, the problem of low energy density of battery cells caused by tab welding is solved, and the energy density of battery cells is improved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-07
- Publication Date
- 2026-03-06
AI Technical Summary
In existing technologies, battery cells with centrally located tabs have lower energy density due to the welding of the tabs to the electrode sheets.
A tab groove is formed in the separator to avoid the tabs, reduce the protrusion of the tabs in the thickness direction, and cover the projection area of the tabs by the tab groove, thereby reducing the overall thickness of the battery cell.
It improves the energy density of the battery cell, reduces the degree of protrusion at the tab position, and reduces the size of the battery cell in the thickness direction.
Smart Images
Figure CN223978041U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of battery technology, and in particular to a battery cell, battery pack and power supply device. Background Technology
[0002] With the development of new energy sources, more and more fields are adopting new energy as a power source. Due to their advantages such as high energy density, rechargeability, safety, and environmental friendliness, battery devices are widely used in new energy vehicles, consumer electronics, energy storage systems, and other fields. For battery cells with centrally located tabs, the tabs are usually electrically connected to the electrode plates by welding, resulting in a thicker welded area between the tab and the electrode plate compared to the main electrode plate area, thus causing a lower energy density in the battery cell. Utility Model Content
[0003] This application aims to address at least one of the technical problems existing in the prior art. To this end, this application proposes a battery cell, a battery pack, and an electrical device that can solve the problem of low energy density in battery cells.
[0004] The battery cell according to the first aspect of this application includes:
[0005] An electrode assembly includes interconnected electrode plates and tabs, and the number of electrode assemblies is two, one of which is a positive electrode assembly and the other is a negative electrode assembly;
[0006] At least two diaphragms, at least one of the diaphragms is located between the positive electrode assembly and the negative electrode assembly, at least one of the diaphragms is located on the side of the negative electrode assembly away from the positive electrode assembly, the diaphragms are formed with tab grooves, the diaphragm located between the positive electrode assembly and the negative electrode assembly is the first diaphragm, and the diaphragm located on the side of the negative electrode assembly away from the positive electrode assembly is the second diaphragm;
[0007] Wherein, when projected along the thickness direction of the battery cell, the projection area of the tab groove corresponding to the first separator covers the projection area of the tab corresponding to the positive electrode assembly, and the projection area of the tab groove corresponding to the second separator covers the projection area of the tab corresponding to the negative electrode assembly.
[0008] The power device according to the embodiments of this application has at least the following beneficial effects:
[0009] In the embodiments of this application, the battery cell is provided with a separator, and the separator has tab grooves that project along the thickness direction. The projected area of the tab groove covers the projected area of the corresponding tab. The tab groove can avoid the tab in the thickness direction. After the battery cell is wound, the tab groove can reduce the degree of protrusion of the tab, thereby reducing the size of the battery cell in the thickness direction and increasing the energy density of the battery cell.
[0010] According to some embodiments of this application, the length and width of the tab groove are respectively greater than the embedding length and width of the corresponding tab;
[0011] Wherein, the embedding length of the electrode tab is the length of the overlapping portion of the projection area of the electrode tab and the projection area of the corresponding electrode sheet, projected along the thickness direction.
[0012] According to some embodiments of this application, the difference between the length of the tab groove and the embedding length of the tab is in the range of 0.5mm to 2.0mm, and / or the difference between the width of the tab groove and the width of the tab is in the range of 1mm to 3mm.
[0013] According to some embodiments of this application, the embedding length of the electrode tab ranges from 15mm to 20mm;
[0014] Wherein, the embedding length of the electrode tab is the length of the overlapping portion of the projection area of the electrode tab and the projection area of the corresponding electrode sheet, projected along the thickness direction.
[0015] According to some embodiments of this application, the electrode includes an interconnected current collector and an active coating, the active coating having a clearance groove, the electrode tab being partially located within the clearance groove, and the electrode tab being electrically connected to the current collector.
[0016] According to some embodiments of this application, the length of the clearance groove is greater than the length of the tab groove, and / or the width of the clearance groove is greater than the width of the tab groove.
[0017] According to some embodiments of this application, the difference between the length of the clearance groove and the embedding length of the electrode tab is in the range of 1mm to 3mm, and / or the difference between the width of the clearance groove and the width of the electrode tab is in the range of 3mm to 5mm.
[0018] According to some embodiments of this application, the electrode assembly further includes adhesive tape, which is adhered to the active coating. The adhesive tape is located on the side of the tab opposite to the corresponding current collector. The tab has a connecting portion for connecting to the current collector. Projected along the thickness direction, the projection area of the connecting portion is located within the projection area of the adhesive tape.
[0019] A second aspect of this application provides a battery pack, comprising:
[0020] Box;
[0021] The battery cell of any of the above, wherein the battery cell is located inside the casing.
[0022] A third aspect of this application provides an electrical device, comprising:
[0023] Main body of the device;
[0024] The battery pack of any of the above is used to power the main body of the device.
[0025] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description
[0026] The present application will be further described below with reference to the accompanying drawings and embodiments, wherein:
[0027] Figure 1 This is a schematic diagram of the assembly of the tab and the electrode sheet in one embodiment of this application;
[0028] Figure 2 This is a simplified structural diagram of a battery cell in one embodiment of this application.
[0029] Figure label:
[0030] 100, Electrode assembly; 110, Electrode sheet; 111, Current collector; 112, Active coating; 112a, Clearance groove; 120, Tab; 200, Positive electrode assembly; 300, Negative electrode assembly; 400, Separator; 400a, Tab groove; 500, First diaphragm; 600, Second diaphragm; 700, Sticker. Detailed Implementation
[0031] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application.
[0032] In the description of this application, it should be understood that the orientation descriptions, such as up, down, front, back, left, right, etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.
[0033] In the description of this application, "several" means one or more, "multiple" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. The use of "first" and "second" in the description is merely for distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.
[0034] In the description of this application, unless otherwise expressly defined, terms such as "setup," "installation," and "connection" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this application in conjunction with the specific content of the technical solution.
[0035] In the description of this application, the terms "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.
[0036] Currently, judging from market trends, the application of battery devices is becoming increasingly widespread. Battery devices are not only used in energy storage power systems such as hydropower, thermal power, wind power, and solar power plants, but also widely applied in electric vehicles such as electric bicycles, electric motorcycles, and electric cars, as well as in military equipment and aerospace. With the continuous expansion of battery device applications, market demand is also constantly increasing.
[0037] In related technologies, in battery cells with centrally located tabs, the tabs are welded to the electrode sheets to achieve electrical connection between them. The tabs protrude from the electrode sheets in the thickness direction. After the battery cell is wound to form a wound cell, the tabs protrude in the thickness direction, thereby lifting the separator and electrode sheets by a certain distance, increasing the overall volume of the battery cell, and resulting in a lower energy density for the battery cell.
[0038] In this embodiment, a tab groove 400a is formed in the separator 400 to avoid the tab 120, thereby reducing the size of the battery cell in the thickness direction and resulting in a higher energy density of the battery cell.
[0039] This application provides an electrical device, which includes a device body and a battery pack, the battery pack being used to supply power to the device body.
[0040] Electrical devices can be, for example, mobile phones, portable devices, laptops, electric vehicles, electric toys, power tools, vehicles, ships, and spacecraft.
[0041] The technical solutions described in this application are not limited to the devices described above, but can also be applied to all devices that use battery devices.
[0042] The battery apparatus mentioned in the embodiments of this application may include one or more battery cell assemblies for providing voltage and capacity. A battery cell assembly may include multiple battery cells connected in series, parallel, or mixed connections via a busbar.
[0043] In some embodiments, a battery cell assembly is typically formed by arranging multiple battery cells.
[0044] As an example, a battery cell assembly can be a battery module, which consists of multiple battery cells 10 arranged and fixed together to form an independent module. As another example, a battery module can be formed by bundling multiple battery cells together with cable ties.
[0045] In some embodiments, the battery device may be a battery pack, which includes a housing and one or more individual battery cells housed within the housing.
[0046] This application also provides a battery pack, which includes a housing and at least one battery cell, with the battery cell located inside the housing.
[0047] In some embodiments of this application, the battery cell can be a secondary battery, which refers to a battery cell that can be recharged to activate the active materials and continue to be used after the battery cell has been discharged.
[0048] The battery cell can be a lithium-ion battery, sodium-ion battery, sodium-lithium-ion battery, lithium metal battery, sodium metal battery, lithium-sulfur battery, magnesium-ion battery, nickel-metal hydride battery, nickel-cadmium battery, lead-acid battery, etc., and the embodiments of this application are not limited to this.
[0049] This application provides a single battery cell; please refer to [link / reference]. Figure 1 and Figure 2The battery cell includes an electrode assembly 100 and at least two separators 400. The electrode assembly 100 includes interconnected electrode plates 110 and tabs 120. There are two electrode assemblies 100, one of which is a positive electrode assembly 200, and the other is a negative electrode assembly 300. At least one separator 400 is located between the positive electrode assembly 200 and the negative electrode assembly 300, and at least one separator 400 is located on the side of the negative electrode assembly 300 opposite to the positive electrode assembly 200. The separator 400 has a tab groove 400a. The separator 400 located between the positive electrode assembly 200 and the negative electrode assembly 300 is a first separator 500, and the separator 400 located on the side of the negative electrode assembly 300 opposite to the positive electrode assembly 200 is a second separator 600. Among them, when projected along the thickness direction of the battery cell, the projection area of the tab groove 400a corresponding to the first separator 500 covers the projection area of the tab 120 corresponding to the positive electrode assembly 200, and the projection area of the tab groove 400a corresponding to the second separator 600 covers the projection area of the tab 120 corresponding to the negative electrode assembly 300.
[0050] The separator 400 refers to a structure used to reduce short circuits between the positive electrode assembly 200 and the negative electrode assembly 300. Exemplarily, the separator 400 can be made of at least one of glass fiber, nonwoven fabric, polyethylene, polypropylene, polyvinylidene fluoride, and ceramic. The separator 400 can be a single-layer film or a multi-layer composite film, without particular limitation. When the separator 400 is a multi-layer composite film, the materials of each layer can be the same or different, without particular limitation. The separator can be a separate component located between the positive and negative electrodes, or it can be attached to the surfaces of the positive and negative electrodes. An inorganic particle coating, an organic particle coating, or an organic / inorganic composite coating can also be applied to the surface of the separator 400.
[0051] For example, the thickness direction of a battery cell refers to the direction perpendicular to the large surface of the battery cell.
[0052] For example, the tab 120 is welded to the electrode 110.
[0053] For example, the battery cell is a square wound cell.
[0054] For example, the thickness direction of a single battery cell is as follows: Figure 2 The direction indicated by the middle arrow R1.
[0055] In the embodiment of this application, the battery cell is provided with a separator 400, and the separator 400 forms a tab groove 400a. Projected along the thickness direction, the projection area of the tab groove 400a covers the projection area of the corresponding tab 120. The tab groove 400a can avoid the tab 120 in the thickness direction. After the battery cell is wound, the tab groove 400a can reduce the degree of protrusion of the tab 120, thereby reducing the size of the battery cell in the thickness direction and increasing the energy density of the battery cell.
[0056] In one embodiment, the length and width of the tab groove 400a are greater than the embedding length and width of the corresponding tab 120, respectively.
[0057] The embedding length of the tab 120 is the length of the overlapping portion of the projection area of the tab 120 and the projection area of the corresponding electrode 110, projected along the thickness direction.
[0058] For example, the length direction of the tab groove 400a is the direction in which the tab 120 extends out of the electrode sheet 110, the length direction of the tab groove 400a is parallel to the length direction of the tab 120, and the length direction of the tab groove 400a is orthogonal to the thickness direction.
[0059] For example, the width direction of the tab groove 400a is orthogonal to both the length direction and the thickness direction of the tab groove 400a.
[0060] For example, the length direction of the tab groove 400a is as follows: Figure 1 The direction indicated by the middle arrow R2, the width direction of the tab groove 400a is as follows: Figure 1 The direction indicated by the middle arrow R3.
[0061] In the embodiment of this application, the length and width of the tab groove 400a are greater than the embedding length and width of the corresponding tab 120, respectively. The larger length and width of the tab groove 400a reduce the assembly difficulty of the tab 120. This also reduces the likelihood that the tab groove 400a cannot completely avoid the tab 120 in the event of manufacturing or assembly errors, thereby reducing the decrease in the energy density of the battery cell.
[0062] It is understood that other embodiments of this application are not limited to the length and width of the tab groove 400a being greater than the embedding length and width of the corresponding tab 120, respectively. For example, the length of the tab groove 400a is equal to the embedding length of the tab 120, and the width of the tab groove 400a is equal to the width of the tab 120.
[0063] In one embodiment, the difference between the length of the tab groove 400a and the embedding length of the tab 120 is in the range of 0.5mm to 2.0mm, and / or the difference between the width of the tab groove 400a and the width of the tab 120 is in the range of 1mm to 3mm.
[0064] For example, the difference between the length of the tab groove 400a and the embedding length of the tab 120 is 0.5mm, 1.0mm, 1.5mm or 2.0mm.
[0065] For example, the difference between the width of the tab groove 400a and the width of the tab 120 is 1.0mm, 1.5mm, 2.0mm, 2.5mm or 3.0mm.
[0066] Understandably, the length and width of the tab groove 400a, and the embedding length and width of the tab 120 can be measured with a ruler under normal temperature and pressure conditions.
[0067] For example, the width of the tab groove 400a is as follows: Figure 2 As shown in the medium dimension D1, the insertion length of the tab 120 is as follows: Figure 1 As shown in the medium dimension D2, the width of the tab 120 is as follows: Figure 1 As shown in the medium dimension D3.
[0068] In the embodiments of this application, the difference between the size of the tab groove 400a and the size of the tab 120 is within a suitable range, which allows the tab groove 400a to avoid the tab 120 as much as possible, and also allows the diaphragm 400 to minimize the possibility of short circuit between the positive electrode assembly 200 and the negative electrode assembly 300.
[0069] It is understood that other embodiments of this application do not limit the difference between the length of the tab groove 400a and the embedding length of the tab 120, or the difference between the width of the tab groove 400a and the width of the tab 120.
[0070] In one embodiment, the embedding length of the tab 120 ranges from 15mm to 20mm;
[0071] The embedding length of the tab 120 is the length of the overlapping portion of the projection area of the tab 120 and the projection area of the corresponding electrode 110, projected along the thickness direction.
[0072] For example, the embedding length of the tab 120 is 15mm, 16mm, 17mm, 18mm, 19mm or 20mm.
[0073] Understandably, the embedding length of tab 120 can be measured using a ruler under normal temperature and pressure conditions.
[0074] In the embodiments of this application, the embedding length of the tab 120 within a suitable range can enable the tab 120 and the electrode 110 to have a high connection strength, making it difficult for the tab 120 to detach from the electrode 110. It can also control the manufacturing cost of the battery cell to a certain extent and reduce the processing difficulty of connecting the tab 120 and the electrode 110.
[0075] It is understood that other embodiments of this application do not limit the embedding length of the tab 120.
[0076] In one embodiment, please refer to Figure 2 The electrode 110 includes a current collector 111 and an active coating 112 connected to each other. The active coating 112 has a relief groove 112a. The tab 120 is partially located in the relief groove 112a and is electrically connected to the current collector 111.
[0077] For example, the electrode 110 corresponding to the positive electrode assembly 200 includes a positive current collector 111 and a positive active coating 112. The positive active coating 112 is coated on at least one large surface of the positive current collector 111.
[0078] For example, the positive current collector 111 may be a metal foil, a conductive polymer material, a carbon material, or a composite current collector 111. For instance, as a metal foil, pure metals, alloys, or surface-treated metals may be used, including but not limited to stainless steel, copper, aluminum, nickel, titanium, or silver. The composite current collector 111 may include a polymer material substrate and a metal layer. The composite current collector 111 can be formed by forming a metal material (aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver, and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).
[0079] Exemplarily, the positive electrode active material may include at least one of the following materials: lithium phosphate, lithium transition metal oxide, and their respective modified compounds. However, this application is not limited to these materials, and other conventional materials that can be used as positive electrode active materials for batteries may also be used. These positive electrode active materials may be used alone or in combination of two or more. Examples of lithium phosphate may include, but are not limited to, at least one of lithium iron phosphate (such as LiFePO4 (also referred to as LFP)), lithium iron phosphate and carbon composites, lithium manganese phosphate (such as LiMnPO4), lithium manganese phosphate and carbon composites, lithium iron manganese phosphate, and lithium iron manganese phosphate and carbon composites.
[0080] For example, the electrode 110 corresponding to the negative electrode assembly 300 includes a negative current collector 111 and a negative active coating 112. The negative active coating 112 is coated on at least one large surface of the negative current collector 111.
[0081] For example, the negative current collector 111 may be a metal foil, a conductive polymer material, a carbon material, or a composite current collector 111. For instance, as a metal foil, pure metals, alloys, or surface-treated metals may be used, including but not limited to stainless steel, copper, aluminum, nickel, titanium, or silver. The composite current collector 111 may include a polymer material substrate and a metal layer. The composite current collector 111 can be formed by forming a metal material (copper, copper alloys, nickel, nickel alloys, titanium, titanium alloys, silver, and silver alloys, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).
[0082] Exemplarily, the negative electrode active material may be a negative electrode active material known in the art for use in battery cells. As an example, the negative electrode active material may include at least one of the following materials: artificial graphite, natural graphite, soft carbon, hard carbon, silicon-based materials, tin-based materials, and lithium titanate, etc. Silicon-based materials may be selected from at least one of elemental silicon, silicon oxide compounds, silicon-carbon composites, silicon-nitrogen composites, and silicon alloys. Tin-based materials may be selected from at least one of elemental tin, tin oxide compounds, and tin alloys. However, this application is not limited to these materials.
[0083] For example, the clearance groove 112a can be formed by scraping the active coating 112 with an external force. The tab 120 is welded to the current collector 111.
[0084] In the embodiment of this application, the active coating 112 has a relief groove 112a, and the tab 120 is partially located within the relief groove 112a. The relief groove 112a can further reduce the degree of protrusion of the tab 120 in the thickness direction of the battery cell, and can expose the current collector 111, which facilitates the welding of the tab 120 and the electrode 110, resulting in a high connection strength between the tab 120 and the electrode 110.
[0085] It is understood that other embodiments of this application do not limit whether the active coating 112 is formed with a clearance groove 112a.
[0086] In one embodiment, the length of the clearance groove 112a is greater than the length of the tab groove 400a, and / or the width of the clearance groove 112a is greater than the width of the tab groove 400a.
[0087] For example, the length direction of the clearance groove 112a is parallel to the length direction of the tab groove 400a, and the width direction of the clearance groove 112a is parallel to the width direction of the tab groove 400a.
[0088] For example, the length of the clearance groove 112a is as follows Figure 1 As shown in the intermediate dimension D4, the width of the clearance groove 112a is as follows: Figure 1 As shown in the medium dimension D5.
[0089] In the embodiment of this application, the length and width of the clearance groove 112a are both greater than the length and width of the tab groove 400a. The larger size of the clearance groove 112a can minimize the assembly difficulty of the tab 120. When manufacturing or assembly errors occur in the tab 120, the clearance groove 112a can be offset from the tab 120 as much as possible, thereby enabling the tab 120 to be welded to the current collector 111 more stably. Furthermore, the tab groove 400a is smaller than the clearance groove 112a, which can reduce the possibility of short circuits between the positive electrode assembly 200 and the negative electrode assembly 300.
[0090] It is understood that other embodiments of this application are not limited to the relationship between the length and width of the clearance groove 112a and the length and width of the tab groove 400a. For example, the length of the clearance groove 112a is equal to the length of the tab groove 400a, and the width of the clearance groove 112a is equal to the width of the tab groove 400a.
[0091] In one embodiment, the difference between the length of the clearance groove 112a and the embedding length of the tab 120 is in the range of 1 mm to 3 mm, and / or the difference between the width of the clearance groove 112a and the width of the tab 120 is in the range of 3 mm to 5 mm.
[0092] For example, the difference between the length of the clearance groove 112a and the embedding length of the tab 120 is 1.0 mm, 1.5 mm, 2.0 mm, 2.5 mm or 3.0 mm.
[0093] For example, the difference between the width of the tab groove 400a and the width of the tab 120 is 3.0mm, 3.5mm, 4.0mm, 4.5mm or 5.0mm.
[0094] It is understandable that the length and width of the clearance groove 112a can be obtained by measuring with a ruler under normal temperature and pressure.
[0095] In the embodiments of this application, the difference between the size of the clearance groove 112a and the size of the tab 120 is within a suitable range, which enables the clearance groove 112a to avoid the tab 120 as much as possible, while also reducing the impact on the stability of the electrode assembly 100 due to the large size of the clearance groove 112a.
[0096] It is understood that other embodiments of this application do not limit the difference between the size of the clearance groove 112a and the size of the tab groove 400a.
[0097] In one embodiment, the electrode assembly 100 further includes adhesive tape, which is adhered to the active coating 112. The adhesive tape is located on the side of the tab 120 opposite to the corresponding current collector 111. The tab 120 has a connecting portion for connecting to the current collector 111. Projected along the thickness direction, the projection area of the connecting portion is located within the projection area of the adhesive tape.
[0098] For example, the length of the adhesive tape is greater than the embedding length of the tab 120, and the width of the adhesive tape is greater than the width of the tab 120.
[0099] For example, adhesive tape is provided on the connecting parts of the tabs 120 corresponding to the positive electrode assembly 200 and the negative electrode assembly 300.
[0100] In the embodiment of this application, the electrode assembly 100 further includes adhesive tape, projected along the thickness direction, with the projection area of the connection portion located within the projection area of the adhesive tape. The tab 120 and the electrode 110 are typically connected by welding. After welding, burrs may appear at the connection portion. During the winding process, these burrs may puncture the electrode 110 or the separator 400. The adhesive tape can isolate the burrs from the separator 400 and the electrode 110, thereby reducing the likelihood of burrs puncturing the separator 400 or the electrode 110 and improving the yield of the battery cell.
[0101] It is understood that other embodiments of this application do not limit whether the electrode assembly 100 is provided with adhesive tape.
[0102] The above embodiments are merely illustrative of the technical solutions of this application and are not intended to limit it. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application, and all should be covered within the scope of the specification of this application. In particular, as long as there is no structural conflict, the various technical features mentioned in the embodiments can be combined in any way. This application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of protection.
Claims
1. A battery cell, characterized by, The application relates to a battery cell, comprising: an electrode assembly, including a tab and a lug connected with each other, the number of the electrode assembly being two, wherein one of the electrode assembly is a positive electrode assembly, and the other of the electrode assembly is a negative electrode assembly; at least two separators, at least one of the separators is located between the positive electrode assembly and the negative electrode assembly, and at least one of the separators is located on the side of the negative electrode assembly away from the positive electrode assembly, the separator is formed with a lug groove, the separator located between the positive electrode assembly and the negative electrode assembly is a first separator, and the separator located on the side of the negative electrode assembly away from the positive electrode assembly is a second separator; wherein, in the thickness direction of the battery cell, the projection area of the lug groove corresponding to the first separator covers the projection area of the lug corresponding to the positive electrode assembly, and the projection area of the lug groove corresponding to the second separator covers the projection area of the lug corresponding to the negative electrode assembly.
2. The battery cell of claim 1, wherein, The length and width of the lug groove are greater than the embedding length and width of the corresponding lug respectively. The embedding length of the lug is the length of the overlapping part of the projection area of the lug and the projection area of the corresponding tab in the thickness direction.
3. The battery cell of claim 2, wherein, The difference between the length of the lug groove and the embedding length of the lug is in the range of 0.5mm to 2.0mm, and / or the difference between the width of the lug groove and the width of the lug is in the range of 1mm to 3mm.
4. The battery cell of claim 1, wherein, The embedding length of the lug is in the range of 15mm to 20mm. The embedding length of the lug is the length of the overlapping part of the projection area of the lug and the projection area of the corresponding tab in the thickness direction.
5. The battery cell according to any one of claims 1 to 4, characterized in that, The tab includes a current collector and an active coating connected with each other, the active coating has a relief groove, and the lug is partially located in the relief groove, and the lug is electrically connected with the current collector.
6. The battery cell of claim 5, wherein, The length of the relief groove is greater than the length of the lug groove, and / or the width of the relief groove is greater than the width of the lug groove.
7. The battery cell of claim 5, wherein, The difference between the length of the relief groove and the embedding length of the lug is in the range of 1mm to 3mm, and / or the difference between the width of the relief groove and the width of the lug is in the range of 3mm to 5mm.
8. The battery cell of claim 5, wherein, The electrode assembly further comprises a gum paper, the gum paper is attached to the active coating, the lug has a connecting part for connecting with the current collector, and in the thickness direction, the projection area of the connecting part is located in the projection area of the gum paper.
9. A battery pack, characterized by, The application relates to a battery cell, comprising: a box body; at least one battery cell as claimed in any one of claims 1 to 8, the battery cell being located in the box body.
10. An electrical device, characterized by The application relates to a battery cell, comprising: a device body; a battery pack as claimed in claim 9, the battery pack being used for supplying power to the device body.