Battery cells and electrical equipment

Abstract

The present application provides a battery cell and an electrical device. Among them, the battery cell includes a packaging bag, an electrode assembly and a tab lead. The electrode assembly is contained in the packaging bag, and the electrode assembly includes a main body and a tab. The tab is located at one end of the main body in the first direction. The tab includes a root, a connecting section and a bending section connected in sequence. The root is connected to the main body, and the bending section is bent relative to the connecting section. One end of the tab lead is electrically connected to the bending section, and the other end extends out of the packaging bag. The angle between the bending section and the thickness direction of the main body is 10° to 80°, and the thickness direction of the main body is perpendicular to the first direction. The battery cell of this structure makes the bending section an inclined structure in the first direction, so that after the bending section is connected to the tab lead, the space occupied by the bending section and the tab lead as a whole in the thickness direction of the main body can be reduced, so as to alleviate the phenomenon that the bending section and the tab lead as a whole exceed the main body in the thickness direction of the main body after being connected, which is conducive to optimizing the thickness 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 and an electrical device. Background Art

[0002] In recent years, with the rapid development of new energy technologies, batteries have been widely used in electronic equipment, electric vehicles, electric two-wheelers, power tools and other fields. Among them, as the size of electronic equipment becomes smaller and thinner, the thickness of the battery is also required. Therefore, the optimization of battery thickness has become an urgent problem to be solved.

[0003] The inventors of the present application have found that in the prior art, the electrode assembly of a battery cell is usually a stacked structure or a wound structure. After the electrode assembly of the battery cell is stacked or wound, the multiple tab units of the electrode assembly need to be stacked after die-cutting to form a tab, and then the tab lead is welded and glued to the tab and then led out of the packaging bag of the battery cell to realize the input or output of electric energy of the battery cell. However, in the existing battery cell, due to the limitations of the assembly process and the uncontrollable assembly precision, the total length of the area where the tab and the tab lead are welded and glued to each other will exceed the thickness of the electrode assembly itself, so that the tab and the tab lead need to occupy a large amount of space in the thickness direction of the battery cell after being welded and assembled to each other, so that the battery cell needs to be designed as a structure with thickened local area, which is not conducive to optimizing the thickness of the battery cell. Summary of the invention

[0004] In view of the above problems, the present application provides a battery cell and an electrical device, which can effectively reduce the thickness of the battery cell.

[0005] In a first aspect, the present application provides a battery cell, comprising a packaging bag, an electrode assembly and a tab lead; the electrode assembly is contained in the packaging bag, the electrode assembly comprising a main body and a tab, the tab being located at one end of the main body in a first direction, the tab comprising a root, a connecting section and a bending section connected in sequence, the root being connected to the main body, and the bending section being bent relative to the connecting section; one end of the tab lead is electrically connected to the bending section, and the other end extends out of the packaging bag; wherein an angle between the bending section and the thickness direction of the main body is α, satisfying 10°≤α≤80°, and the thickness direction of the main body is perpendicular to the first direction.

[0006] In the above technical scheme, the electrode ear of the electrode assembly includes a root, a connecting section and a bending section which are connected in sequence, the root is connected to the main body of the electrode assembly, and the bending section is bent relative to the connecting section, so that the electrode ear of the electrode assembly has a U-shaped structure, and the bending section connecting the electrode ear and the electrode ear lead is set to 10 degrees to 80 degrees with the thickness direction of the main body, so that the bending section is a structure inclined in a first direction, so that after the bending section is connected to the electrode ear lead, the space occupied by the bending section and the electrode ear lead as a whole in the thickness direction of the main body can be reduced, so as to alleviate the phenomenon that the bending section and the electrode ear lead as a whole exceed the main body in the thickness direction of the main body after being connected, which is beneficial to optimize the thickness of the battery cell.

[0007] In some embodiments, the bending section is inclined toward a direction approaching the main body.

[0008] In the above technical solution, the bending section is arranged to be a structure inclined toward the main body in the first direction, that is, the bending section is inclined toward the main body after being bent relative to the connecting section, thereby reducing the space occupied by the bending section in the thickness direction of the main body and optimizing the space occupied by the pole ear in the first direction, so as to improve the space utilization inside the battery cell, thereby effectively improving the energy density of the battery cell.

[0009] In some embodiments, along the first direction, a maximum distance between a surface of the root facing the bending segment and a surface of the bending segment facing away from the root is L, satisfying 1.5 mm ≤ L ≤ 3 mm.

[0010] In the above technical solution, by setting the maximum distance between the surface of the root of the pole ear facing the bending section and the surface of the bending section of the pole ear away from the root at 1.5mm to 3mm, that is, the maximum size of the connection position between the root and the connecting section and the bending position of the bending section relative to the connecting section in the first direction is 1.5mm to 3mm. The battery cell with such a structure can, on the one hand, alleviate the phenomenon that the space for the bending section to tilt toward the main body is too small due to its too small size, making it inconvenient to adjust the space occupied by the bending section in the thickness direction of the main body; on the other hand, it can alleviate the phenomenon that the space occupied by the pole ear in the first direction is too large due to its too large size, resulting in low internal space utilization of the battery cell and loss of energy density of the battery cell.

[0011] In some embodiments, the angle between the bent section and the thickness direction of the main body is α, satisfying 20°≤α≤60°.

[0012] In the above technical scheme, by setting the angle between the extension direction of the bending section and the thickness direction of the main body at 20 degrees to 60 degrees, that is, the angle between the bending section and the first direction is set to 30 degrees to 70 degrees, on the one hand, it can alleviate the phenomenon that the bending section occupies too much space in the thickness direction of the main body due to the angle between the extension direction of the bending section and the thickness direction of the main body is too small, so as to cause the bending section to occupy too much space in the thickness direction of the main body after being connected to the pole ear lead; on the other hand, it can alleviate the phenomenon that the pole ear occupies too much space in the first direction due to the angle between the extension direction of the bending section and the thickness direction of the main body is too large, which is beneficial to improve the space utilization inside the battery cell and reduce the loss of energy density of the battery cell.

[0013] In some embodiments, an angle α between the bending section and the thickness direction of the main body is 27°≤α≤33°.

[0014] In some embodiments, an angle α between the bending section and the thickness direction of the main body is 42°≤α≤48°.

[0015] In the above technical solution, α is set as a preferred solution to more reasonably balance the thickness of the tab and the space utilization of the tab in the first direction.

[0016] In some embodiments, the connecting segment is substantially parallel to the first direction.

[0017] In the above technical solution, by setting the connecting section as a structure roughly parallel to the first direction, on the one hand, it is convenient to process the pole ear, which is conducive to reducing the processing difficulty. On the other hand, it can save the space occupied by the pole ear in the thickness direction of the main body, so as to further optimize the space occupied by the bending section in the thickness direction of the main body after being connected to the pole ear lead.

[0018] In some embodiments, the tab lead includes a first section and a second section connected to each other, the first section is located in the packaging bag and connected to the bending section, and the second section extends out of the packaging bag along the first direction; wherein the first section is bent relative to the second section, and the first section is parallel to the bending section.

[0019] In the above technical solution, by setting the pole ear lead to a first section and a second section that are connected to each other, the second section extends out of the packaging bag along the first direction and the first section is a structure that is bent relative to the second section, so that the first section and the bent section are parallel to each other. On the one hand, the battery cell adopting this structure facilitates the connection between the bent section of the pole ear and the first section of the pole ear lead, which is beneficial to reducing the difficulty of assembly. On the other hand, the bent section and the first section are both structures that are inclined in the first direction, and the second section extends along the first direction, which is beneficial to saving the overall space occupied by the pole ear and the pole ear lead in the thickness direction of the main body after the pole ear and the pole ear lead are connected to each other, so as to optimize the thickness of the battery cell.

[0020] In some embodiments, the first section is connected to a side of the bent section facing away from the main body.

[0021] In the above technical solution, by connecting the first section of the tab lead to the side of the bent section away from the main body, it is helpful to reduce the difficulty of assembling the first section and the bent section, so as to improve the production efficiency of the battery cell.

[0022] In some embodiments, the battery cell further includes an insulating member, which is disposed on a side of the first section away from the bending section along the first direction, and is configured to insulate and isolate the first section from the packaging bag.

[0023] In the above technical solution, an insulating member is provided on the side of the first section of the tab lead away from the bending section, so that the insulating member can insulate and isolate the first section from the packaging bag, thereby reducing the risk of short circuit between the first section and the packaging bag, thereby improving the safety of the battery cell.

[0024] In some embodiments, along the thickness direction of the main body, the tab and the tab lead do not extend beyond two sides of the main body.

[0025] In the above technical solution, by setting the tabs and the tab leads in the thickness direction of the main body so as not to exceed the two sides of the main body, the phenomenon of local thickening of the battery cell caused by the tabs and the tab leads occupying too much space in the thickness direction of the main body can be alleviated, which is beneficial to optimize the overall thickness of the battery cell and reduce the processing difficulty of the battery cell.

[0026] In some embodiments, the thickness of the body is D, satisfying D≤2.5 mm.

[0027] In the above technical solution, the thickness of the main body of the electrode assembly is set to be less than or equal to 2.5 mm to meet the manufacturing requirements of the ultra-thin battery cell.

[0028] In some embodiments, the thickness of the body is D, satisfying D≤2 mm.

[0029] In the above solution, the thickness of the main body of the electrode assembly is set to be less than or equal to 2 mm to meet the manufacturing requirements of the ultra-thin battery cell.

[0030] In some embodiments, the electrode assembly is a laminated structure, and the thickness direction of the main body is the electrode sheet stacking direction of the electrode assembly.

[0031] In the above technical solution, the electrode assembly is set as a stacked structure, and the thickness direction of the main body is the stacking direction of the electrode sheets of the electrode assembly, so as to optimize the thickness of the battery cell while improving the internal space utilization of the battery cell and reducing the processing difficulty.

[0032] In a second aspect, the present application also provides an electrical device, comprising the above-mentioned battery cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] 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 also be obtained based on these drawings.

[0034] Figure 1 A cross-sectional view of a battery cell provided in some embodiments of the present application;

[0035] Figure 2 for Figure 1 A partial enlarged view of the cell at A shown;

[0036] Figure 3 A partial cross-sectional view of an electrode assembly of a battery cell provided in some embodiments of the present application.

[0037] Icons: 100-battery cell; 10-packaging bag; 11-lead-out hole; 20-electrode assembly; 21-main body; 22-ear; 221-root; 222-connecting section; 223-bending section; 30-ear lead; 31-first section; 32-second section; 40-weld stamp; 50-seal; 60-insulation; X-first direction; Y-thickness direction of the main body. DETAILED DESCRIPTION

[0038] In order to make the purpose, technical solutions and advantages of the present application clearer, the technical solutions 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, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field belong to the scope of protection of this application.

[0039] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as those commonly understood by technicians in the technical field to which this application belongs; 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" and any variations thereof in the specification and claims of this application and the above-mentioned drawings 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.

[0040] 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.

[0041] 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.

[0042] 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.

[0043] In the present application, the battery cell may be a lithium-ion battery, a sodium-ion battery, a magnesium-ion battery, etc., and the embodiments of the present application are not limited to this.

[0044] The battery cell includes a packaging bag, an electrode assembly and an electrolyte, and the packaging bag is used to contain the electrode assembly and the electrolyte. The electrode assembly is composed of a positive electrode sheet, a negative electrode sheet and a separator. The battery cell mainly relies on the movement of metal ions between the positive electrode sheet and the negative electrode sheet to work. The positive electrode sheet includes a positive electrode collector and a positive electrode active material layer, the positive electrode active material layer is coated on the surface of the positive electrode collector, and the part of the positive electrode collector that is not coated with the positive electrode active material layer is used as a positive electrode ear to realize the input or output of electric energy of the positive electrode sheet through the positive electrode ear. Taking lithium-ion batteries as an example, the material of the positive electrode collector can be aluminum, and the positive electrode active material can be lithium cobalt oxide, lithium iron phosphate, ternary material or lithium manganese oxide. The negative electrode sheet includes a negative electrode collector and a negative electrode active material layer, the negative electrode active material layer is coated on the surface of the negative electrode collector, and the part of the negative electrode collector that is not coated with the negative electrode active material layer is used as a negative electrode ear to realize the input or output of electric energy of the negative electrode sheet through the negative electrode ear. The negative electrode current collector may be made of copper, and the negative electrode active material may be made of carbon material or silicon material.

[0045] The material of the isolation film may be polypropylene (PP) or polyethylene (PE), etc. In addition, the electrode assembly may be a winding structure or a stacked structure, which is not limited in the embodiment of the present application.

[0046] In this application, the thickness limit error is within 3°, such as β = 90°. Considering the possible errors in the process or measurement, it should be considered that 90°±3° is within the protection scope of this application. Similarly, parallel and perpendicular in this application should be understood as approximately parallel.

[0047] The inventors found that for general battery cells, especially for the manufacturing process of battery cells with thinner electrode assemblies (bare battery cells), the electrode assemblies of the battery cells are usually set to a laminated structure or a wound structure, that is, the positive electrode sheets and the negative electrode sheets are alternately stacked or wound together. However, after the electrode assembly of the battery cell is laminated or wound, the multiple tab units of the electrode assembly need to be stacked after die-cutting to form tabs, and then the tab leads are welded and glued to the tabs to lead the tab leads out of the packaging bag of the battery cell to realize the input or output of the electric energy of the battery cell. However, due to the limitations of the current assembly process and the influence of the uncontrollable assembly accuracy, the total length of the area where the tabs and the tab leads are welded and glued to each other will exceed the thickness of the electrode assembly itself, so that the tabs and the tab leads need to occupy a large amount of space in the thickness direction of the battery cell after being welded and assembled to each other, resulting in the need to design the battery cell as a structure with thickened local areas, which is not conducive to optimizing the thickness of the battery cell.

[0048] Based on the above considerations, in order to solve the problem that the tabs of the electrode assembly and the tab leads occupy too much space in the thickness direction of the battery cell after being connected to each other, the inventors have designed a battery cell after in-depth research, which includes a packaging bag, an electrode assembly and a tab lead. The electrode assembly is contained in the packaging bag, and the electrode assembly includes a main body and a tab. The tab is located at one end of the main body in the first direction. The tab includes a root, a connecting section and a bending section connected in sequence. The root is connected to the main body, and the bending section is bent relative to the connecting section. One end of the tab lead is electrically connected to the bending section, and the other end extends out of the packaging bag. The angle between the bending section and the main body in the thickness direction is α, which satisfies 10°≤α≤80°, and the thickness direction of the main body is perpendicular to the first direction.

[0049] In a battery cell of this structure, the electrode tab of the electrode assembly includes a root portion, a connecting section and a bending section which are connected in sequence, the root portion is connected to the main body of the electrode assembly, and the bending section is bent relative to the connecting section, so that the electrode tab of the electrode assembly has a U-shaped structure, and the bending section connecting the tab and the tab lead is set to have an angle of 10° to 80° with the thickness direction of the main body, so that the bending section is a structure inclined in a first direction, so that after the bending section is connected to the tab lead, the space occupied by the connection position of the bending section and the tab lead in the thickness direction of the main body can be reduced, so as to alleviate the phenomenon that the overall area after the bending section and the tab lead are connected exceeds the main body in the thickness direction of the main body, which is beneficial to optimize the thickness of the battery cell.

[0050] The embodiments of the present application provide an electrical device that uses a battery cell as a power source. The electrical device may be, but is not limited to, a mobile phone, a tablet, a laptop computer, an electric toy, an electric tool, an electric vehicle, an electric car, a ship, a spacecraft, and the like.

[0051] It should be noted that each battery cell may be a secondary battery or a primary battery; for example, a lithium ion battery, a sodium ion battery or a magnesium ion battery, but not limited thereto. Figure 1 middle, Figure 1 This is a cross-sectional view of a battery cell 100 provided in some embodiments of the present application, and the battery cell 100 is a rectangular parallelepiped structure.

[0052] According to some embodiments of the present application, referring to Figure 1 , and please refer to Figure 2 and Figure 3 , Figure 2 for Figure 1 The partial enlarged view of the cell 100 at A is shown. Figure 3 A partial cross-sectional view of an electrode assembly 20 of a battery cell 100 provided in some embodiments of the present application. The present application provides a battery cell 100, which includes a packaging bag 10, an electrode assembly 20, and a tab lead 30. The electrode assembly 20 is contained in the packaging bag 10, and the electrode assembly 20 includes a main body 21 and a tab 22. The tab 22 is located at one end of the main body 21 in the first direction X. The tab 22 includes a root 221, a connecting section 222, and a bending section 223 connected in sequence. The root 221 is connected to the main body 21, and the bending section 223 is bent relative to the connecting section 222. One end of the tab lead 30 is electrically connected to the bending section 223, and the other end extends out of the packaging bag 10. Among them, the angle between the bending section 223 and the thickness direction Y of the main body is α, which satisfies 10°≤α≤80°, and the thickness direction Y of the main body is perpendicular to the first direction X.

[0053] The pole ear 22 of the electrode assembly 20 includes a root portion 221, a connecting section 222 and a bending section 223 which are connected in sequence. The root portion 221 is connected to the main body 21 of the electrode assembly 20, and the bending section 223 is bent relative to the connecting section 222, so that the pole ear 22 of the electrode assembly 20 has a U-shaped structure. The bending section 223 connecting the pole ear 22 and the pole ear lead 30 is set to be 10 degrees to 80 degrees with the thickness direction Y of the main body, so that the bending section 223 is a structure inclined in the first direction X, so that after the bending section 223 is connected to the pole ear lead 30, the space occupied by the bending section 223 and the pole ear lead 30 as a whole in the thickness direction Y of the main body can be reduced, so as to alleviate the phenomenon that the bending section 223 and the pole ear lead 30 as a whole after being connected exceed the main body 21 in the thickness direction Y of the main body, which is beneficial to optimize the thickness of the battery cell 100.

[0054] The packaging bag 10 can also be used to contain electrolytes, such as electrolytes. The packaging bag 10 can be in various structural forms, such as a cylinder, a cuboid, etc. For example, Figure 1 In the embodiment, the packaging bag 10 is a rectangular parallelepiped structure. The material of the packaging bag 10 can be an aluminum-plastic film.

[0055] exist Figure 1 In the embodiment, the packaging bag 10 is a hollow structure, and a receiving space for receiving the electrode assembly 20 is formed inside the packaging bag 10 . The electrode assembly 20 is received in the receiving space of the packaging bag 10 .

[0056] It should be noted that the electrode assembly 20 is a component in the battery cell 100 where an electrochemical reaction occurs. The electrode assembly 20 may include a negative electrode sheet, a separator, and a positive electrode sheet. The electrode assembly 20 may be a wound structure formed by winding the negative electrode sheet, the separator, and the positive electrode sheet, or a laminated structure formed by stacking the negative electrode sheet, the separator, and the positive electrode sheet.

[0057] In some embodiments, the electrode assembly 20 is a laminated structure, and the thickness direction Y of the main body is the stacking direction of the pole pieces of the electrode assembly 20. By setting the electrode assembly 20 as a laminated structure, and the thickness direction Y of the main body being the stacking direction of the pole pieces of the electrode assembly 20, it is convenient to optimize the thickness of the battery cell 100 while improving the internal space utilization of the battery cell 100 and reducing the processing difficulty.

[0058] Among them, the electrode assembly 20 is a laminated structure, that is, the electrode assembly 20 is a laminated structure formed by alternatingly stacking the negative electrode sheets, the isolation membranes and the positive electrode sheets, so that the stacking direction of the negative electrode sheets, the isolation membranes and the positive electrode sheets is the thickness direction Y of the main body.

[0059] exist Figure 2 and Figure 3 In the figure, the pole ear 22 includes a root 221, a connecting section 222 and a bending section 223 connected in sequence, the root 221 is connected to the main body 21, and the bending section 223 is bent relative to the connecting section 222, so that the root 221 and the bending section 223 are arranged relatively in the first direction X, that is, the root 221, the connecting section 222 and the bending section 223 are connected in sequence to form a "U"-shaped structure, wherein the pole ear 22 includes a plurality of pole ear 22 units, each positive pole sheet or each negative pole sheet is provided with a pole ear 22 unit, and a plurality of pole ear 22 units with the same polarity are gathered together at the connecting section 222 and the bending section 223 of the pole ear 22.

[0060] It should be noted that the bending section 223 is bent relative to the connecting section 222, so that the position where the bending section 223 and the connecting section 222 are connected to each other can be various. For example, Figure 2 and Figure 3In the embodiment, the connection position between the bending section 223 and the connecting section 222 is an arc transition, that is, the bending section 223 includes a first part and a second part, the first part is the area of ​​the bending section 223 arc transition, that is, the second part is connected to the connecting section 222 through the first part, and the second part is the area where the bending section 223 is connected to the tab lead 30. In this embodiment, the angle between the bending section 223 and the thickness direction Y of the main body is α, and 10°≤α≤80° means that the angle formed by the second part of the bending section 223 and the thickness direction Y of the main body is 10 degrees to 80 degrees. Of course, in other embodiments, the connection position between the bending section 223 and the connecting section 222 may not be an arc transition, that is, the connection position between the bending section 223 and the connecting section 222 forms an angle, that is, the bending section 223 is a flat plate structure as a whole.

[0061] In some embodiments, see Figure 3 As shown, the thickness of the main body 21 is D, which satisfies D≤2.5 mm. By setting the thickness of the main body 21 of the electrode assembly 20 to be less than or equal to 2.5 mm, the manufacturing requirements of the ultra-thin battery cell 100 are met.

[0062] According to some embodiments of the present application, see Figure 1 , Figure 2 and Figure 3 As shown, the bending section 223 is inclined toward the direction close to the main body 21. That is, in the first direction X, the end of the bending section 223 connected to the connecting section 222 is farther away from the main body 21 than the end of the bending section 223 away from the connecting section 222.

[0063] By setting the bending section 223 to be a structure inclined toward the direction close to the main body 21 in the first direction X, that is, the bending section 223 is inclined toward the direction of the main body 21 after being bent relative to the connecting section 222, thereby reducing the space occupied by the bending section 223 in the thickness direction Y of the main body and optimizing the space occupied by the tab 22 in the first direction X, so as to improve the space utilization inside the battery cell 100, thereby effectively improving the energy density of the battery cell 100.

[0064] Of course, the structure of the electrode assembly 20 is not limited thereto. In other embodiments, the bending section 223 of the electrode tab 22 may also be configured to deviate in the first direction X in a direction away from the main body 21 .

[0065] In some embodiments, see Figure 3 As shown, along the first direction X, the maximum distance between the surface of the root 221 facing the bending section 223 and the surface of the bending section 223 away from the root 221 is L, which satisfies 1.5mm≤L≤3mm. That is, in the first direction X, the distance from the end of the tab 22 farthest from the body 21 to the surface of the root 221 facing the bending section 223 is L.

[0066] By setting the maximum distance between the surface of the root 221 of the pole ear 22 facing the bending section 223 and the surface of the bending section 223 of the pole ear 22 away from the root 221 to 1.5mm to 3mm, that is, the maximum size of the connection position between the root 221 and the connecting section 222 and the bending position of the bending section 223 relative to the connecting section 222 in the first direction X is 1.5mm to 3mm. The battery cell 100 adopting this structure can, on the one hand, alleviate the phenomenon that the space for the bending section 223 to tilt toward the direction close to the main body 21 is too small due to its too small size, making it inconvenient to adjust the occupied space of the bending section 223 in the thickness direction Y of the main body. On the other hand, it can alleviate the phenomenon that the space occupied by the pole ear 22 in the first direction X is too large due to its too large size, resulting in low internal space utilization of the battery cell 100, resulting in loss of energy density of the battery cell 100.

[0067] According to some embodiments of this application, please continue to refer to Figure 3 As shown, the angle between the bending section 223 and the thickness direction Y of the main body is α, which satisfies 20°≤α≤60°. In other words, the angle of the bending section 223 deviating from the thickness direction Y of the main body is between 20 degrees and 60 degrees.

[0068] By setting the angle between the extension direction of the bending section 223 and the thickness direction Y of the main body at 20 degrees to 60 degrees, that is, setting the angle between the bending section 223 and the first direction X at 30 degrees to 70 degrees, on the one hand, it can alleviate the phenomenon that the bending section 223 occupies too much space in the thickness direction Y of the main body due to the angle between the extension direction of the bending section 223 and the thickness direction Y of the main body is too small, so as to cause the bending section 223 to occupy too much space in the thickness direction Y of the main body after being connected to the tab lead 30. On the other hand, it can alleviate the phenomenon that the tab 22 occupies too much space in the first direction X due to the angle between the extension direction of the bending section 223 and the thickness direction Y of the main body is too large, which is beneficial to improve the space utilization inside the battery cell 100 and reduce the loss of energy density of the battery cell 100.

[0069] In some embodiments, the angle α between the bent section and the thickness direction of the main body is 27°≤α≤33°. This allows the battery cell to meet the ultra-thin thickness requirement while avoiding excessive head space occupation. The thickness D of the main body can meet D≤2.5mm.

[0070] In some embodiments, the angle α between the bent section and the thickness direction of the main body is 42°≤α≤48°. The thickness can be made thinner while the battery cell meets the head space utilization rate. The thickness D of the main body can meet D≤2.0mm.

[0071] In some embodiments, the connecting section 222 is substantially parallel to the first direction X.

[0072] By setting the connecting section 222 to a structure that is roughly parallel to the first direction X, on the one hand, it is convenient to process the pole ear 22, which is helpful to reduce the processing difficulty. On the other hand, it can save the space occupied by the pole ear 22 in the thickness direction Y of the main body, so as to further optimize the space occupied by the bending section 223 in the thickness direction Y of the main body after being connected to the pole ear lead 30.

[0073] According to some embodiments of the present application, see Figure 1 and Figure 2 As shown, the tab lead 30 includes a first section 31 and a second section 32 connected to each other, the first section 31 is located in the packaging bag 10 and connected to the bending section 223, and the second section 32 extends out of the packaging bag 10 along the first direction X. The first section 31 is bent relative to the second section 32, and the first section 31 is parallel to the bending section 223.

[0074] By setting the tab lead 30 as a first section 31 and a second section 32 connected to each other, the second section 32 extends out of the packaging bag 10 along the first direction X and the first section 31 is a structure bent relative to the second section 32, so that the first section 31 and the bent section 223 are parallel to each other. The battery cell 100 adopting this structure is convenient for the bent section 223 of the tab 22 to be connected to the first section 31 of the tab lead 30, which is conducive to reducing the difficulty of assembly. On the other hand, the bent section 223 and the first section 31 are both structures inclined in the first direction X, and the second section 32 extends along the first direction X, which is conducive to saving the space occupied by the tab 22 and the tab lead 30 in the thickness direction Y of the main body after the tab 22 and the tab lead 30 are connected to each other, so as to optimize the thickness of the battery cell 100.

[0075] In the thickness direction Y of the body, the first section 31 of the tab lead 30 is bent relative to the second section 32 to the side of the second section 32 facing the bent section 223 of the tab 22 , so that the first section 31 is connected to the bent section 223 .

[0076] Optionally, there are many ways to connect the first section 31 and the bent section 223, such as welding, clamping, etc. Figure 2 In the embodiment, the first section 31 and the bending section 223 are welded to each other to form a welding mark 40 . The welding mark 40 and the bending section 223 are parallel to each other, that is, the extending direction of the welding mark 40 is the same as the extending direction of the bending section 223 .

[0077] In some embodiments, a lead-out hole 11 is disposed at one end of the packaging bag 10 close to the tab 22 in the first direction X, and the second section 32 passes through the lead-out hole 11 and extends out of the packaging bag 10 .

[0078] Optionally, the battery cell 100 may further include a sealant 50 , which is disposed between the second section 32 and the hole wall of the lead-out hole 11 , and is configured to seal the gap between the second section 32 and the hole wall of the lead-out hole 11 .

[0079] Exemplarily, the sealing member 50 may be made of various materials, such as rubber, silicone or plastic.

[0080] According to some embodiments of the present application, see Figure 1 and Figure 2 As shown, the first section 31 is connected to the side of the bending section 223 away from the main body 21. That is, the first section 31 is located in the first direction X on the side of the bending section 223 away from the main body 21.

[0081] By connecting the first section 31 of the tab lead 30 to the side of the bent section 223 facing away from the main body 21 , it is helpful to reduce the difficulty of assembling the first section 31 and the bent section 223 , so as to improve the production efficiency of the battery cell 100 .

[0082] In some embodiments, the battery cell 100 may further include an insulating member 60 . Along the first direction X, the insulating member 60 is disposed on a side of the first section 31 away from the bent section 223 . The insulating member 60 is configured to insulate and isolate the first section 31 from the packaging bag 10 .

[0083] The insulating member 60 and the first section 31 may be connected in various ways, such as bonding, clamping, etc. Exemplarily, the insulating member 60 is bonded to a side of the first section 31 that is away from the main body 21 .

[0084] Exemplarily, the insulating member 60 may be made of various materials, such as rubber, silicone or plastic.

[0085] By arranging an insulating member 60 on the side of the first section 31 of the tab lead 30 away from the bending section 223, the insulating member 60 can insulate and isolate the first section 31 and the packaging bag 10, thereby reducing the risk of short circuit between the first section 31 and the packaging bag 10, thereby improving the safety of the battery cell 100.

[0086] In some embodiments, see Figure 1 As shown, along the thickness direction Y of the main body, the tab 22 and the tab lead 30 do not exceed the two sides of the main body 21. That is, in the thickness direction Y of the main body, the tab 22 and the tab lead 30 are connected to form a whole body located between the two sides of the main body 21.

[0087] By setting the tab 22 and the tab lead 30 in the thickness direction Y of the main body so as not to exceed the two sides of the main body 21, the phenomenon of local thickening of the battery cell 100 caused by the tab 22 and the tab lead 30 occupying too much space in the thickness direction Y of the main body can be alleviated, which is beneficial to optimize the overall thickness of the battery cell 100 and reduce the processing difficulty of the battery cell 100.

[0088] According to some embodiments of the present application, an electrical device is further provided, comprising a battery cell 100 according to any of the above schemes, and the battery cell 100 is used to provide electrical energy to the electrical device.

[0089] The electric device may be any of the aforementioned devices or systems using the battery cell 100 .

[0090] 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.

[0091] The above are only preferred embodiments of the present application and are not intended 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: Packaging bags; an electrode assembly, contained in the packaging bag, the electrode assembly comprising a main body and a tab, the tab being located at one end of the main body in the first direction, the tab comprising a root portion, a connecting section and a bending section connected in sequence, the root portion being connected to the main body, and the bending section being bent relative to the connecting section; as well as A tab lead, one end of which is electrically connected to the bending section and the other end of which extends out of the packaging bag; Among them, the bending section is inclined towards the direction close to the main body, and the root and the bending section are arranged relatively in the first direction, the angle between the bending section and the thickness direction of the main body is α, satisfying 10°≤α≤80°, and the thickness direction of the main body is perpendicular to the first direction.

2. The battery cell according to claim 1, characterized in that: Along the first direction, a maximum distance between a surface of the root facing the bending section and a surface of the bending section away from the root is L, satisfying 1.5 mm ≤ L ≤ 3 mm.

3. The battery cell according to claim 1, characterized in that: An included angle α between the bending section and the main body in a thickness direction is 20°≤α≤60°.

4. The battery cell according to claim 3, characterized in that: An included angle α between the bending section and the main body in the thickness direction is 27°≤α≤33°.

5. The battery cell according to claim 3, characterized in that: An included angle α between the bending section and the main body in the thickness direction is 42°≤α≤48°.

6. The battery cell according to claim 1, characterized in that: The connecting section is parallel to the first direction.

7. The battery cell according to any one of claims 1 to 6, characterized in that: The tab lead comprises a first section and a second section connected to each other, the first section is located in the packaging bag and connected to the bending section, and the second section extends out of the packaging bag along the first direction; Wherein, the first section is bent relative to the second section, and the first section is parallel to the bent section.

8. The battery cell according to claim 7, characterized in that: The first section is connected to a side of the bent section facing away from the main body.

9. The battery cell according to claim 8, characterized in that: The battery cell also includes: An insulating member is disposed on a side of the first section away from the bending section along the first direction, and is configured to insulate and isolate the first section from the packaging bag.

10. The battery cell according to claim 1, characterized in that: Along the thickness direction of the main body, the tabs and the tab leads do not exceed two sides of the main body.

11. The battery cell according to claim 1, characterized in that: The thickness of the main body is D, satisfying D≤2.5mm.

12. The battery cell according to claim 1, characterized in that: The thickness of the main body is D, satisfying D≤2.0mm.

13. The battery cell according to claim 1, characterized in that: The electrode assembly is a laminated structure, and the thickness direction of the main body is the stacking direction of the electrode sheets of the electrode assembly.

14. An electrical device, characterized in that: Comprising a battery cell according to any one of claims 1-13.

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