Battery cell and electric equipment

Abstract

The invention provides a battery cell and electric equipment, the battery cell comprises a packaging bag, an electrode assembly, a first electric connecting piece and an insulating piece, and the electrode assembly is formed by winding a first pole piece, a diaphragm and a second pole piece which are stacked. The first pole piece comprises a first coating area and a first empty foil area. In the length direction of the unfolded first pole piece, the length of the first empty foil area is L1, the length of the first coating area is L2, and L1 / L2 is larger than or equal to 0.5 and smaller than or equal to 1. The insulating part is arranged on the outer surface of the outermost ring of the first empty foil area. The current-carrying capacity of the first empty foil area is high, rapid charging and discharging of the battery cell are facilitated, preparation of the first empty foil area is facilitated, the preparation efficiency of the battery cell can be improved, and the preparation cost of the battery cell can be reduced; the insulating part can realize insulation between the first empty foil area and the packaging bag or other parts, so that the possibility of corrosion rupture of the packaging bag is reduced, and the safety of the battery cell can be improved; and the insulating part occupies a small space, so that the energy density of the battery cell can be improved.

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] With the rapid development of electronic information technology, various electronic devices are also developing towards intelligence and multifunctionality, and the requirements for battery preparation efficiency are getting higher and higher. Therefore, how to improve the efficiency of battery preparation has become an urgent problem to be solved in the battery field. Summary of the invention

[0003] The present application provides a battery cell and an electrical device, which can improve the preparation efficiency of the battery cell.

[0004] In the first aspect, the present application provides a battery cell, which includes a packaging bag, an electrode assembly, a first electrical connector and an insulating member. The electrode assembly is contained in the packaging bag, and the electrode assembly is wound by stacking a first pole piece, a diaphragm, and a second pole piece. The first pole piece includes a first coating area and a first empty foil area. Along a first direction, the first empty foil area is arranged on one side of the first coating area, and the first direction is parallel to the winding axis of the electrode assembly. Along the length direction of the unfolded first pole piece, the length of the first empty foil area is L1, and the length of the first coating area is L2, 0.5≤L1 / L2≤1. One end of the first electrical connector is connected to the first empty foil area, and the other end of the first electrical connector extends out of the packaging bag. The insulating member is arranged on the outer surface of the outermost circle of the first empty foil area.

[0005] In the above technical scheme, when L1 / L2 is greater than or equal to 0.5, the length of the first empty foil area can be longer, and the current-carrying capacity of the first empty foil area can be higher, which is conducive to the rapid charging and discharging of the battery cell; when L1 / L2 is less than or equal to 1, it is convenient to prepare the first empty foil area; therefore, when 0.5≤L1 / L2≤1, it can not only make the current-carrying capacity of the first empty foil area higher, which is conducive to the rapid charging and discharging of the battery cell, but also facilitate the preparation of the first empty foil area. Furthermore, when preparing the first empty foil area, die-cutting is not required or only one die-cutting is required. Compared with the current battery cell in which multiple first empty foil areas are formed by multiple die-cutting, the preparation process of the battery cell of the present application is simpler, which can improve the preparation efficiency of the battery cell and reduce the preparation cost of the battery cell. By arranging the insulating member on the outer surface of the outermost circle of the first empty foil area, the insulating member can achieve insulation between the first empty foil area and the packaging bag or other components, reducing the possibility of electrochemical reaction between the first empty foil area and the packaging bag when the battery cell is energized, thereby reducing the possibility of corrosion and rupture of the packaging bag caused by the contact between the first empty foil area and the packaging bag, thereby improving the safety of the battery cell. In addition, the insulating member occupies a small space, which is conducive to improving the energy density of the battery cell.

[0006] In some embodiments of the present application, the electrode assembly includes a straight region and two bending regions, and along a second direction, the two bending regions are respectively located at two ends of the straight region, and the second direction is perpendicular to the first direction.

[0007] In the above technical solution, the electrode assembly includes a straight area and two bending areas, and along the second direction, the two bending areas are respectively located at the two ends of the straight area, and the second direction is perpendicular to the first direction, so that the thickness of the electrode assembly is smaller and the application range of the battery cell is larger.

[0008] In some embodiments of the present application, the packaging bag includes a main body and an edge sealing portion, the electrode assembly is accommodated in the main body, and the first electrical connector extends out of the packaging bag from the edge sealing portion. The battery cell also includes a seal, which is used to seal the first electrical connector and the edge sealing portion. Along the third direction, the projection of the insulating member does not overlap with the projection of the seal. The first direction, the second direction, and the third direction are perpendicular to each other.

[0009] In the above technical solution, by making the packaging bag include a main body and an edge sealing part, the electrode assembly is accommodated in the main body, so that the edge sealing part can realize the sealing of the packaging bag, reduce the possibility of leakage of electrolyte in the packaging bag, and improve the safety of the battery cell; by making the first electrical connector extend from the edge sealing part of the packaging bag, the first electrical connector can be connected to the load, thereby realizing the electrical connection between the load and the electrode assembly, and realizing the power supply of the battery cell to the load. By making the battery cell also include a sealing member, the sealing member is used to seal and connect the first electrical connector and the edge sealing part, the sealing between the first electrical connector and the edge sealing part can be further strengthened, the possibility of leakage of electrolyte in the packaging bag from the first electrical connector and the edge sealing part can be reduced, and the safety of the battery cell can be improved. By making the projection of the insulating member and the projection of the sealing member not overlap along the third direction, the influence of the insulating member on the sealing member sealing the first electrical connector and the edge sealing part can be reduced, and the possibility of leakage of electrolyte in the packaging bag from the first electrical connector and the edge sealing part can be further reduced, and the safety of the battery cell can be improved.

[0010] In some embodiments of the present application, along the first direction, the width of the insulating member is W1 mm, the width of the first empty foil area is W2 mm, the spacing distance between the sealing member and the first coating area is D1 mm, and W2≤W1≤D1.

[0011] In the above technical solution, by making the width W2 of the first empty foil area less than or equal to the width W1 of the insulating member along the first direction, the insulating member can cover the first empty foil area, so that the insulating member has a better insulation effect on the first empty foil area and the packaging bag, further reducing the possibility of corrosion and rupture of the packaging bag, and further improving the safety of the battery cell; by making the width W1 of the insulating member less than or equal to the spacing distance D1 between the seal and the first coating area along the first direction, the insulating member can be arranged between the seal and the first coating area, and the possibility of the insulating member overlapping with the seal is small, which can reduce the influence of the insulating member on the sealing of the first electrical connector and the edge seal by the seal, further reducing the possibility of leakage of electrolyte in the packaging bag from the first electrical connector and the edge seal, and improving the safety of the battery cell; and / or, the possibility of the insulating member overlapping with the first coating area is small, which can reduce the thickness of the electrode assembly, which is beneficial to improving the energy density of the battery cell.

[0012] In some embodiments of the present application, 1≤D1 / W1≤1.5, and / or, 1≤W1 / W2≤2.5.

[0013] In the above technical solution, when D1 / W1 is greater than or equal to 1, the insulating member can be arranged between the sealing member and the first coating area, and the possibility of overlapping between the insulating member and the sealing member is small, which can reduce the influence of the insulating member on the sealing of the first electrical connector and the edge sealing portion by the sealing member, further reduce the possibility of leakage of electrolyte in the packaging bag from between the first electrical connector and the edge sealing portion, and improve the safety of the battery cell; and / or, the possibility of overlapping between the insulating member and the first coating area is small, which can reduce the thickness of the electrode assembly, which is beneficial to improve the energy density of the battery cell; when D1 / W1 is less than or equal to 1.5, the spacing distance between the insulating member and the sealing member and the first coating area can be small, reducing the distance between the electrode assembly and the packaging bag The waste of space between them is beneficial to improving the energy density of the battery cell; therefore, when 1≤D1 / W1≤1.5, the insulating member can be arranged between the sealing member and the first coating area, and the possibility of overlapping between the insulating member and the sealing member is small, which can reduce the influence of the insulating member on the sealing of the first electrical connector and the edge sealing portion by the sealing member, further reduce the possibility of leakage of electrolyte in the packaging bag from between the first electrical connector and the edge sealing portion, and improve the safety of the battery cell; and / or, the possibility of overlapping between the insulating member and the first coating area is small, which can reduce the thickness of the electrode assembly, which is beneficial to improving the energy density of the battery cell; and can reduce the waste of space between the electrode assembly and the packaging bag, which is beneficial to improving the energy density of the battery cell.

[0014] When W1 / W2 is greater than or equal to 1, the insulating member can cover the first empty foil area, so that the insulating member has a better insulating effect on the first empty foil area and the packaging bag, further reducing the possibility of corrosion and rupture of the packaging bag, and further improving the safety of the battery cell; when W1 / W2 is less than or equal to 2.5, the width of the portion of the insulating member that exceeds the first empty foil area is smaller, which is beneficial to reducing the distance between the side of the electrode assembly where the first empty foil area is provided and the packaging bag, thereby facilitating the improvement of the energy density of the battery cell; therefore, when 1≤W1 / W2≤2.5, the insulating member can cover the first empty foil area, so that the insulating member has a better insulating effect on the first empty foil area and the packaging bag, further reducing the possibility of corrosion and rupture of the packaging bag, and further improving the safety of the battery cell, and can also help reduce the distance between the side of the electrode assembly where the first empty foil area is provided and the packaging bag, thereby facilitating the improvement of the energy density of the battery cell.

[0015] In some embodiments of the present application, 6mm≤W2≤18mm.

[0016] In the above technical scheme, when W2 is greater than or equal to 6mm, the area in which the first empty foil area can be connected to the first electrical connector is larger, which is beneficial to improve the connection strength between the first empty foil area and the first electrical connector and improve the reliability of the battery cell; when W2 is less than or equal to 18mm, the space occupied by the first empty foil area can be smaller, which is beneficial to improve the energy density of the battery cell; therefore, when 6mm≤W2≤18mm, the area in which the first empty foil area can be connected to the first electrical connector can be larger, which is beneficial to improve the connection strength between the first empty foil area and the first electrical connector and improve the reliability of the battery cell; and the space occupied by the first empty foil area can be smaller, which is beneficial to improve the energy density of the battery cell.

[0017] In some embodiments of the present application, along the first direction, the insulating member exceeds the first empty foil area.

[0018] In the above technical solution, by making the insulating member extend beyond the first empty foil area along the first direction, the insulating member can better cover the first empty foil area, and the insulating member has higher insulation reliability between the first empty foil area and the packaging bag, further reducing the possibility of corrosion and rupture of the packaging bag, and further improving the safety of the battery cell.

[0019] In some embodiments of the present application, the first empty foil area is wound into multiple turns, and the multiple turns of the first empty foil area are gathered along the third direction. The angle between each turn of the first empty foil area located in the straight area and the first direction is θ, 0°≤θ≤60°; the first direction, the second direction and the third direction are perpendicular to each other.

[0020] In the above technical scheme, by winding the first empty foil area into multiple circles and the multiple circles of the first empty foil area are gathered along the third direction, the space occupied by the first empty foil area can be reduced and it is convenient to connect with the first electrical connector; when the angle θ between each circle of the first empty foil area located in the straight area and the first direction is greater than or equal to 0°, it is convenient to gather the first empty foil area; when the angle θ between each circle of the first empty foil area located in the straight area and the first direction is less than or equal to 60°, the possibility of the first empty foil area being damaged due to excessive bending angle can be reduced, which is beneficial to improve the connection reliability between the first empty foil area and the first electrical connector; therefore, when 0°≤θ≤60°, it is convenient to gather the first empty foil area and reduce the possibility of the first empty foil area being damaged due to excessive bending angle, which is beneficial to improve the connection reliability between the first empty foil area and the first electrical connector.

[0021] In some embodiments of the present application, the insulating member includes a first portion and a second portion, the first portion is disposed in the first empty foil area, and the second portion is disposed in the first coating area.

[0022] In the above technical solution, when the insulating member is only provided in the first empty foil area, due to process errors, the edge of the insulating member and the first coating area cannot be completely fitted, and a gap may be formed between the insulating member and the first coating area, thereby causing a portion of the first empty foil area to be exposed, and there may be a risk of the first empty foil area contacting the packaging bag. Therefore, by making the insulating member include a first part and a second part, the first part is provided in the first empty foil area, and the second part is provided in the first coating area, the insulating member can completely cover the side of the first empty foil area close to the first coating area, so that the insulating member has a better insulation effect between the first empty foil area and the packaging bag, reducing the possibility of corrosion and rupture of the packaging bag, and improving the safety of the battery cell.

[0023] In some embodiments of the present application, along the first direction, one side of the first coating area connected to the first empty foil area exceeds the second pole piece, and the width of the exceeding portion is W3 mm, and the width of the second portion is W4 mm, and W4≤W3.

[0024] In the above technical solution, along the first direction, the side where the first coated area is connected to the first empty foil area exceeds the second pole piece. Therefore, a step is formed on the side of the second pole piece close to the first empty foil area and the side where the first coated area is connected to the first empty foil area. By making the width of the exceeding part W3 mm and the width of the second part W4 mm, W4≤W3, the insulating member and the second pole piece do not overlap, and at least part of the second part is located in the step in the thickness direction of the first pole piece. The second part does not exceed the second pole piece in the thickness direction of the first pole piece or the thickness of the part exceeding the second pole piece is smaller, so that the insulating member has less influence on the thickness of the electrode assembly, which is beneficial to improve the energy density of the battery cell.

[0025] In some embodiments of the present application, W4≤W3≤5mm.

[0026] In the above technical solution, by making W4≤W3≤5mm, the space occupied by the excess part and the second part can be made smaller, which is beneficial to improving the energy density of the battery cell; after the first coating area expands, the possibility of the insulating part acting on the first empty foil area and the first coating area to cause local stress unevenness of the electrode assembly is small, thereby reducing the possibility of damage to the electrode assembly.

[0027] In some embodiments of the present application, the thickness of the first empty foil area is H1 μm, the thickness of the insulating member is H2 μm, and 2≤H2 / H1≤5.

[0028] In the above technical solution, when H2 / H1 is greater than or equal to 2, the insulating member can be made thicker than the first empty foil area, and the possibility of the burrs on the first empty foil area piercing the insulating member is small, thereby reducing the possibility of the burrs on the first empty foil area contacting the packaging bag, reducing the possibility of the packaging bag being corroded and broken, and further improving the safety of the battery cell; when H2 / H1 is less than or equal to 5, the first empty foil area can provide sufficient supporting force for the insulating member, reducing the possibility of the insulating member exerting excessive pressure on the first empty foil area and causing the first empty foil area to be broken and damaged, thereby improving the reliability of the battery cell; therefore, when 2≤H2 / H1≤5, it can not only reduce the possibility of the burrs on the first empty foil area piercing the insulating member, thereby reducing the possibility of the burrs on the first empty foil area contacting the packaging bag, reducing the possibility of the packaging bag being corroded and broken, and further improving the safety of the battery cell; it can also enable the first empty foil area to provide sufficient supporting force for the insulating member, reducing the possibility of the insulating member exerting excessive pressure on the first empty foil area and causing the first empty foil area to be broken and damaged, thereby improving the reliability of the battery cell.

[0029] In some embodiments of the present application, the insulating member is disposed around the outermost first empty foil area for multiple turns.

[0030] In the above technical solution, by arranging the insulating member around the first empty foil area of ​​the outermost circle for multiple turns, the insulating member can provide better insulation effect between the first empty foil area and the packaging bag, further reducing the possibility of corrosion and rupture of the packaging bag, and further improving the safety of the battery cell.

[0031] In some embodiments of the present application, the second electrode sheet includes a second coated area and a second empty foil area, and along the first direction, the first empty foil area and the second empty foil area are respectively located at two ends of the electrode assembly, and along the length direction of the first electrode sheet after unfolding, the length of the second empty foil area is L3, and the length of the second coated area is L4, and 0.5≤L3 / L4≤1. The battery cell includes a second electrical connector, one end of the second electrical connector is connected to the second empty foil area, and the other end of the second electrical connector extends out of the packaging bag.

[0032] In the above technical solution, when L3 / L4 is greater than or equal to 0.5, the length of the first empty foil area can be longer, and the current carrying capacity of the first empty foil area is higher, which is conducive to the rapid charging and discharging of the battery cell; when L3 / L4 is less than or equal to 1, it is convenient to prepare the first empty foil area; therefore, when 0.5≤L3 / L4≤1, it can not only make the current carrying capacity of the first empty foil area higher, which is conducive to the rapid charging and discharging of the battery cell, but also facilitate the preparation of the first empty foil area. And when preparing the second empty foil area, there is no need to perform die cutting or only one die cutting is required. Compared with the battery cell currently formed by multiple second empty foil areas through multiple die cutting, the preparation process of the battery cell of the present application is simpler, which can improve the preparation efficiency of the battery cell and reduce the preparation cost of the battery cell.

[0033] In some embodiments of the present application, the packaging bag includes an aluminum-plastic film, the first electrode sheet is a negative electrode sheet, and the second electrode sheet is a positive electrode sheet.

[0034] In the above technical solution, by making the packaging bag include an aluminum-plastic film, the packaging bag can have a better protective effect on the electrode assembly and is convenient for forming the edge sealing portion. Since the negative electrode collector of the negative electrode plate is usually made of copper, and copper and aluminum will produce an electrochemical reaction when electrically connected, causing corrosion of the packaging bag, it is necessary to provide an insulating member between the negative electrode collector and the aluminum-plastic film, while the positive electrode collector of the positive electrode plate is usually made of aluminum, which is not easy to produce an electrochemical reaction with the aluminum-plastic film.

[0035] In a second aspect, the present application provides an electrical device, including a battery cell as described above, and the battery cell is used to provide electrical energy. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] 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.

[0037] Figure 1 A schematic diagram of the structure of a battery cell provided in some embodiments of the present application;

[0038] Figure 2 A schematic cross-sectional view of a partial structure of a battery cell provided in some embodiments of the present application;

[0039] Figure 3 A schematic diagram of an expanded partial structure of a battery cell provided in some embodiments of the present application;

[0040] Figure 4 A schematic diagram of a partial structure of a battery cell provided in some embodiments of the present application;

[0041] Figure 5A schematic diagram of a partial structure of a battery cell provided in some embodiments of the present application;

[0042] Figure 6 A schematic diagram of the structure of a battery cell provided in some embodiments of the present application before the first empty foil area is folded;

[0043] Figure 7 A schematic diagram of the structure of a battery cell after the first empty foil area is folded in according to some embodiments of the present application;

[0044] Figure 8 A schematic diagram of a cross-sectional structure of a battery cell provided in some embodiments of the present application after the first empty foil area is folded;

[0045] Fig. 9 A schematic diagram of a partial structure of a battery cell provided in some embodiments of the present application;

[0046] Fig.10 A schematic diagram of a partial structure of a battery cell provided in some embodiments of the present application.

[0047] Icon: 10-battery cell; 100-packaging bag; 110-main body; 120-edge sealing; 200-electrode assembly; 201-straight area; 202-bending area; 210-first pole piece; 211-first coating area; 212-first empty foil area; 220-diaphragm; 230-second pole piece; 231-second coating area; 232-second empty foil area; 300-first electrical connector; 310-welding area; 400-insulating member; 410-first part; 420-second part; 500-sealing member; 600-second electrical connector; X-first direction; Y-second direction; Z-third direction. DETAILED DESCRIPTION

[0048] 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.

[0049] 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 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" in the specification and claims of this application and the above-mentioned figure descriptions and any variations thereof are intended to cover non-exclusive inclusions.

[0050] 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.

[0051] 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.

[0052] 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.

[0053] With the development of the new energy industry, batteries are gradually developing in the direction of high energy density and high power density, and the requirements for battery preparation efficiency are becoming higher and higher. However, in the preparation process of wound batteries, the current collector of the pole piece is usually die-cut in multiple places along one side of its width direction to form multiple empty foil areas spaced along the length direction of the current collector. After the electrode assembly is wound, the multiple empty foil areas are connected in the thickness direction of the electrode assembly. The die-cutting process of the current collector is relatively complicated, and the preparation difficulty and cost are high, which affects the preparation efficiency of the battery cell. For full-ear batteries, generally, before the pole piece is wound, an insulating part is set on the full ear. After the electrode assembly is wound, the thickness of the insulating part is relatively large, which affects the energy density of the battery cell.

[0054] In order to improve the preparation efficiency of battery cells, the present application provides a battery cell, which includes a packaging bag, an electrode assembly, a first electrical connector and an insulating member. The electrode assembly is contained in the packaging bag, and the electrode assembly is wound by stacking a first pole piece, a diaphragm, and a second pole piece. The first pole piece includes a first coating area and a first empty foil area. Along a first direction, the first empty foil area is arranged on one side of the first coating area, and the first direction is parallel to the winding axis of the electrode assembly. Along the length direction of the first pole piece after unfolding, the length of the first empty foil area is L1, and the length of the first coating area is L2, 0.5≤L1 / L2≤1. One end of the first electrical connector is connected to the first empty foil area, and the other end of the first electrical connector extends out of the packaging bag. The insulating member is arranged on the outer surface of the outermost circle of the first empty foil area.

[0055] In a battery cell of this structure, when L1 / L2 is greater than or equal to 0.5, the length of the first empty foil area can be longer and the current-carrying capacity of the first empty foil area can be higher, which is conducive to rapid charging and discharging of the battery cell; when L1 / L2 is less than or equal to 1, it is convenient to prepare the first empty foil area; therefore, when 0.5≤L1 / L2≤1, it is possible to make the current-carrying capacity of the first empty foil area higher, which is conducive to rapid charging and discharging of the battery cell, and it is also convenient to prepare the first empty foil area. Furthermore, when preparing the first empty foil area, die-cutting is not required or only one die-cutting is required. Compared with the current battery cell in which multiple first empty foil areas are formed by multiple die-cutting, the preparation process of the battery cell of the present application is simpler, which can improve the preparation efficiency of the battery cell and reduce the preparation cost of the battery cell. By arranging the insulating member on the outer surface of the outermost circle of the first empty foil area, the insulating member can achieve insulation between the first empty foil area and the packaging bag or other components, reducing the possibility of electrochemical reaction between the first empty foil area and the packaging bag when the battery cell is energized, thereby reducing the possibility of corrosion and rupture of the packaging bag caused by the contact between the first empty foil area and the packaging bag, thereby improving the safety of the battery cell. In addition, the insulating member occupies a small space, which is conducive to improving the energy density of the battery cell.

[0056] The battery cell provided in the embodiment of the present application can be a secondary battery or a primary battery, for example, a lithium ion battery, a sodium ion battery or a magnesium ion battery, etc., which is not limited in the embodiment of the present application. The electrochemical device can be cylindrical, flat, rectangular or other shapes, etc., which is not limited in the embodiment of the present application.

[0057] 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, an energy storage product, etc.

[0058] See also Figures 1 to 4 , Figure 1 A schematic diagram of the structure of a battery cell provided in some embodiments of the present application; Figure 2 A schematic cross-sectional view of a partial structure of a battery cell provided in some embodiments of the present application; Figure 3 A schematic diagram of an expanded partial structure of a battery cell provided in some embodiments of the present application; Figure 4 A schematic diagram of a partial structure of a battery cell provided in some embodiments of the present application.

[0059] In the first aspect, the present application provides a battery cell 10, which includes a packaging bag 100, an electrode assembly 200, a first electrical connector 300, and an insulating member 400. The electrode assembly 200 is contained in the packaging bag 100, and the electrode assembly 200 is wound by stacking a first pole piece 210, a diaphragm 220, and a second pole piece 230. The first pole piece 210 includes a first coating area 211 and a first empty foil area 212. Along the first direction X, the first empty foil area 212 is arranged on one side of the first coating area 211, and the first direction X is parallel to the winding axis of the electrode assembly 200. Along the length direction after the first pole piece 210 is unfolded, the length of the first empty foil area 212 is L1, and the length of the first coating area 211 is L2, and 0.5≤L1 / L2≤1. For example, L1 / L2 can be 0.5, 0.8 or 1, etc.

[0060] When L1 / L2 is greater than or equal to 0.5, the length of the first empty foil area 212 can be longer, and the current carrying capacity of the first empty foil area 212 is higher, which is conducive to the rapid charge and discharge of the battery cell 10; when L1 / L2 is less than or equal to 1, it is convenient to prepare the first empty foil area 212; therefore, when 0.5≤L1 / L2≤1, it is possible to make the current carrying capacity of the first empty foil area 212 higher, which is conducive to the rapid charge and discharge of the battery cell 10, and it is convenient to prepare the first empty foil area 212. And when preparing the first empty foil area 212, there is no need to perform die cutting or only one die cutting is required. Compared with the battery cell 10 that is currently formed by multiple die cuttings to form multiple first empty foil areas 212, the preparation process of the battery cell 10 of the present application is simpler, which can improve the preparation efficiency of the battery cell 10 and reduce the preparation cost of the battery cell 10.

[0061] In some embodiments, one end of the first electrical connector 300 is connected to the first empty foil area 212, and the other end of the first electrical connector 300 extends out of the packaging bag 100. The insulating member 400 is disposed on the outer surface of the outermost circle of the first empty foil area 212.

[0062] By arranging the insulating member 400 on the outer surface of the outermost circle of the first empty foil area 212, the insulating member 400 can achieve insulation between the first empty foil area 212 and the packaging bag 100 or other components, thereby reducing the possibility of the first empty foil area 212 contacting the packaging bag 100 and causing an electrochemical reaction between the first empty foil area 212 and the packaging bag 100 when the battery cell 10 is energized, thereby causing corrosion and rupture of the packaging bag 100, thereby improving the safety of the battery cell 10; and the insulating member 400 occupies a smaller space, which is conducive to improving the energy density of the battery cell 10.

[0063] In some embodiments, the packaging bag 100 includes an aluminum-plastic film.

[0064] By making the packaging bag 100 include an aluminum-plastic film, the packaging bag 100 can better protect the electrode assembly 200 and facilitate the formation of the edge sealing portion 120 .

[0065] In some embodiments, the packaging bag 100 is also used to contain electrolyte. The battery cell 10 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 current collector and a positive active material layer, the positive active material layer is coated on the surface of the positive current collector, and the part of the positive current collector that is not coated with the positive active material layer is used as a positive electrode ear, so as 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 current collector can be aluminum, and the positive active material can be lithium cobalt oxide, lithium iron phosphate, ternary material or lithium manganese oxide. The negative electrode sheet includes a negative current collector and a negative active material layer, the negative active material layer is coated on the surface of the negative current collector, and the part of the negative current collector that is not coated with the negative active material layer is used as a negative electrode ear, so as to realize the input or output of electric energy of the negative electrode sheet through the negative electrode ear. The material of the negative current collector can be copper, and the negative active material can be a carbon material or a silicon material. The material of the separator can be polypropylene (PP) or polyethylene (PE), etc. The electrolyte may include an organic solvent, an electrolyte lithium salt, and the like.

[0066] In some embodiments, the first electrode plate 210 is a negative electrode plate, and the second electrode plate 230 is a positive electrode plate.

[0067] Since the negative electrode collector of the negative electrode plate is usually made of copper, and copper and aluminum will produce an electrochemical reaction when electrically connected, causing corrosion of the packaging bag 100, it is necessary to set an insulating member 400 between the negative electrode collector and the aluminum-plastic film, while the positive electrode collector of the positive electrode plate is usually made of aluminum, which is not easy to produce an electrochemical reaction with the aluminum-plastic film.

[0068] In some embodiments, the battery cell 10 is arranged in a rectangular parallelepiped.

[0069] In some embodiments, the first electrical connector 300 may be made of a material with good electrical conductivity, such as a metal material such as lead or copper.

[0070] See also Figure 2 In some embodiments, the electrode assembly 200 includes a straight region 201 and two bending regions 202 . Along the second direction Y, the two bending regions 202 are respectively located at two ends of the straight region 201 . The second direction Y is perpendicular to the first direction X.

[0071] By making the electrode assembly 200 include a straight area 201 and two bending areas 202, along the second direction Y, the two bending areas 202 are respectively located at the two ends of the straight area 201, and the second direction Y is perpendicular to the first direction X, so that the thickness of the electrode assembly 200 is small and the application range of the battery cell 10 is larger.

[0072] See also Figure 1 and Figure 4In some embodiments, the packaging bag 100 includes a main body 110 and an edge sealing portion 120 , the electrode assembly 200 is accommodated in the main body 110 , and the first electrical connector 300 extends out of the packaging bag 100 from the edge sealing portion 120 .

[0073] By making the packaging bag 100 include a main body 110 and a sealing edge 120, the electrode assembly 200 is accommodated in the main body 110, so that the sealing edge 120 can achieve sealing of the packaging bag 100, reduce the possibility of electrolyte leakage in the packaging bag 100, and improve the safety of the battery cell 10; by making the first electrical connector 300 extend from the sealing edge 120 out of the packaging bag 100, the first electrical connector 300 can be connected to the load, thereby achieving electrical connection between the load and the electrode assembly 200, and realizing power supply of the battery cell 10 to the load.

[0074] In some embodiments, the battery cell 10 further includes a seal 500 , which is used to seal and connect the first electrical connector 300 and the edge sealing portion 120 .

[0075] By making the battery cell 10 also include a seal 500, the seal 500 is used to seal the first electrical connector 300 and the edge seal 120, so that the sealing between the first electrical connector 300 and the edge seal 120 can be further strengthened, and the possibility of leakage of the electrolyte in the packaging bag 100 from between the first electrical connector 300 and the edge seal 120 can be reduced, thereby improving the safety of the battery cell 10.

[0076] See also Figure 5 , Figure 5 A schematic diagram of a partial structure of a battery cell provided in some embodiments of the present application.

[0077] In some embodiments, along the third direction Z, a projection of the insulating member 400 and a projection of the sealing member 500 do not overlap.

[0078] In some embodiments, the first direction X, the second direction Y, and the third direction Z are perpendicular to each other.

[0079] By ensuring that the projection of the insulating member 400 and the projection of the sealing member 500 do not overlap along the third direction Z, the influence of the insulating member 400 on the sealing of the first electrical connector 300 and the edge sealing portion 120 by the sealing member 500 can be reduced, further reducing the possibility of leakage of the electrolyte in the packaging bag 100 from between the first electrical connector 300 and the edge sealing portion 120, thereby improving the safety of the battery cell 10.

[0080] In some embodiments, along the first direction X, the width of the insulating member 400 is W1 mm, the width of the first empty foil area 212 is W2 mm, the distance between the sealing member 500 and the first coating area 211 is D1 mm, and W2≤W1≤D1. For example, W1 can be D1, W2 can be D1, or W1 can be D1, W2 can be 0.9*D1, or W1 can be 0.9*D1, W2 can be 0.8*D1, etc.

[0081] By making the width W2 of the first empty foil area 212 along the first direction X less than or equal to the width W1 of the insulating member 400, the insulating member 400 can cover the first empty foil area 212, so that the insulating member 400 has a better insulation effect between the first empty foil area 212 and the packaging bag 100, further reducing the possibility of corrosion and rupture of the packaging bag 100, and further improving the safety of the battery cell 10; by making the width W1 of the insulating member 400 along the first direction X less than or equal to the spacing distance D1 between the sealing member 500 and the first coating area 211, the insulating member 400 can be set It is placed between the sealing member 500 and the first coating area 211, and the possibility of the insulating member 400 overlapping with the sealing member 500 is small, which can reduce the influence of the insulating member 400 on the sealing of the first electrical connector 300 and the edge sealing portion 120 by the sealing member 500, and further reduce the possibility of the electrolyte in the packaging bag 100 leaking from between the first electrical connector 300 and the edge sealing portion 120, thereby improving the safety of the battery cell 10; and / or, the possibility of the insulating member 400 overlapping with the first coating area 211 is small, which can reduce the thickness of the electrode assembly 200, which is beneficial to improving the energy density of the battery cell 10.

[0082] In some embodiments, 1≤D1 / W1≤1.5. For example, D1 / W1 may be 1, 1.2, or 1.5.

[0083] When D1 / W1 is greater than or equal to 1, the insulating member 400 can be disposed between the sealing member 500 and the first coating area 211, and the insulating member 400 is less likely to overlap with the sealing member 500, which can reduce the influence of the insulating member 400 on the sealing member 500 of the first electrical connector 300 and the edge sealing portion 120, further reducing the possibility of leakage of the electrolyte in the packaging bag 100 from between the first electrical connector 300 and the edge sealing portion 120, thereby improving the safety of the battery cell 10; and / or, the insulating member 400 is less likely to overlap with the first coating area 211, which can reduce the thickness of the electrode assembly 200, thereby facilitating an improvement in the energy density of the battery cell 10; when D1 / W1 is less than or equal to 1.5, the spacing between the insulating member 400 and the sealing member 500 and the first coating area 211 can be reduced, thereby reducing the spacing between the electrode assembly 200 and the packaging bag 100. The waste of space is beneficial to improving the energy density of the battery cell 10; therefore, when 1≤D1 / W1≤1.5, the insulating member 400 can be arranged between the sealing member 500 and the first coating area 211, and the possibility of the insulating member 400 overlapping with the sealing member 500 is small, which can reduce the influence of the insulating member 400 on the sealing member 500 of the first electrical connector 300 and the edge sealing portion 120, and further reduce the possibility of leakage of the electrolyte in the packaging bag 100 from between the first electrical connector 300 and the edge sealing portion 120, thereby improving the safety of the battery cell 10; and / or, the possibility of the insulating member 400 overlapping with the first coating area 211 is small, which can reduce the thickness of the electrode assembly 200, thereby improving the energy density of the battery cell 10; and can reduce the waste of space between the electrode assembly 200 and the packaging bag 100, thereby improving the energy density of the battery cell 10.

[0084] In some embodiments, 1≤W1 / W2≤2.5. For example, W1 / W2 may be 1, 1.8, or 2.5.

[0085] When W1 / W2 is greater than or equal to 1, the insulating member 400 can cover the first empty foil area 212, so that the insulating member 400 has a better insulation effect on the first empty foil area 212 and the packaging bag 100, further reducing the possibility of corrosion and rupture of the packaging bag 100, and further improving the safety of the battery cell 10; when W1 / W2 is less than or equal to 2.5, the width of the portion of the insulating member 400 that exceeds the first empty foil area 212 is smaller, which is beneficial to reducing the distance between the side of the electrode assembly 200 provided with the first empty foil area 212 and the packaging bag 100, This is beneficial to improving the energy density of the battery cell 10; therefore, when 1≤W1 / W2≤2.5, the insulating member 400 can cover the first empty foil area 212, so that the insulating member 400 has a better insulation effect between the first empty foil area 212 and the packaging bag 100, further reducing the possibility of corrosion and rupture of the packaging bag 100, and further improving the safety of the battery cell 10, and it can also be beneficial to reduce the distance between the side of the electrode assembly 200 where the first empty foil area 212 is provided and the packaging bag 100, thereby helping to improve the energy density of the battery cell 10.

[0086] In some embodiments, 6 mm ≤ W2 ≤ 18 mm. For example, W2 may be 6 mm, 12 mm, or 18 mm.

[0087] When W2 is greater than or equal to 6 mm, the area over which the first empty foil area 212 can be connected to the first electrical connector 300 is larger, which is beneficial to improving the connection strength between the first empty foil area 212 and the first electrical connector 300 and improving the reliability of the battery cell 10; when W2 is less than or equal to 18 mm, the space occupied by the first empty foil area 212 can be smaller, which is beneficial to improving the energy density of the battery cell 10; therefore, when 6 mm ≤ W2 ≤ 18 mm, the area over which the first empty foil area 212 can be connected to the first electrical connector 300 is larger, which is beneficial to improving the connection strength between the first empty foil area 212 and the first electrical connector 300 and improving the reliability of the battery cell 10; and the space occupied by the first empty foil area 212 can be smaller, which is beneficial to improving the energy density of the battery cell 10.

[0088] In some embodiments, along the first direction X, the insulating member 400 extends beyond the first empty foil area 212 .

[0089] By making the insulating member 400 extend beyond the first empty foil area 212 along the first direction X, the insulating member 400 can better cover the first empty foil area 212, and the insulating member 400 has higher insulation reliability between the first empty foil area 212 and the packaging bag 100, thereby further reducing the possibility of corrosion and rupture of the packaging bag 100, and further improving the safety of the battery cell 10.

[0090] In some other embodiments, along the first direction X, the insulating member 400 may be aligned with the edge of the first empty foil area 212 .

[0091] In some embodiments, the first electrical connector 300 is welded to the outermost circle of the first empty foil area 212 to form a welding area 310 , and the insulating member 400 covers the welding area 310 .

[0092] By welding the first electrical connector 300 to the outermost circle of the first empty foil area 212 to form a welding area 310, the connection strength between the first electrical connector 300 and the first empty foil area 212 can be increased, and the possibility of the first electrical connector 300 being separated from the first empty foil area 212 is reduced; by making the insulating member 400 cover the welding area 310, the possibility of the welding area 310 contacting the packaging bag 100 can be reduced.

[0093] See also Figures 6 to 8 , Figure 6 A schematic diagram of the structure of a battery cell provided in some embodiments of the present application before the first empty foil area is folded; Figure 7 A schematic diagram of the structure of a battery cell after the first empty foil area is folded in according to some embodiments of the present application; Figure 8 This is a schematic diagram of the cross-sectional structure of a battery cell after the first empty foil area is folded in according to some embodiments of the present application.

[0094] In some embodiments, the first empty foil area 212 is wound into multiple turns, and the multiple turns of the first empty foil area 212 are gathered along the third direction Z. The angle between each turn of the first empty foil area 212 located in the straight area 201 and the first direction X is θ, and 0°≤θ≤60°. The first direction X, the second direction Y, and the third direction Z are perpendicular to each other. For example, θ can be 2°, 30°, or 60°.

[0095] By winding the first empty foil area 212 into multiple turns, the multiple turns of the first empty foil area 212 are gathered along the third direction Z, so that the space occupied by the first empty foil area 212 can be reduced, and it is convenient to connect with the first electrical connector 300; when the angle θ between each turn of the first empty foil area 212 located in the straight area 201 and the first direction X is greater than or equal to 0°, it is convenient to gather the first empty foil area 212; when the angle θ between each turn of the first empty foil area 212 located in the straight area 201 and the first direction X is less than or equal to 60°, it is possible to reduce the possibility of the first empty foil area 212 being damaged due to excessive bending angle, which is beneficial to improve the connection reliability between the first empty foil area 212 and the first electrical connector 300; therefore, when 0°≤θ≤60°, it is possible to facilitate the gathering of the first empty foil area 212, and reduce the possibility of the first empty foil area 212 being damaged due to excessive bending angle, which is beneficial to improve the connection reliability between the first empty foil area 212 and the first electrical connector 300.

[0096] See also Figure 5In some embodiments, the insulating member 400 is only disposed in the first empty foil area 212, that is, along the first direction X, the insulating member 400 does not exceed the side where the first empty foil area 212 is connected to the first coating area 211. This makes the insulating member 400 not overlap with the first coating area 211 in the third direction Z, reduces the influence of the insulating member 400 on the thickness of the electrode assembly 200, and is conducive to improving the energy density of the battery cell 10.

[0097] See also Fig. 9 , Fig. 9 A schematic diagram of a partial structure of a battery cell provided in some embodiments of the present application.

[0098] In some other embodiments, the insulating member 400 includes a first portion 410 and a second portion 420 . The first portion 410 is disposed in the first empty foil area 212 , and the second portion 420 is disposed in the first coating area 211 .

[0099] When the insulating member 400 is only disposed on the first empty foil area 212, due to process errors, the edges of the insulating member 400 and the first coating area 211 cannot be completely attached, and a gap may be formed between the insulating member 400 and the first coating area 211, thereby causing a portion of the first empty foil area 212 to be exposed, and there may be a risk that the first empty foil area 212 contacts the packaging bag 100. Therefore, by making the insulating member 400 include a first portion 410 and a second portion 420, the first portion 410 is disposed on the first empty foil area 212, and the second portion 420 is disposed on the first coating area 211, the insulating member 400 can completely cover the side of the first empty foil area 212 close to the first coating area 211, so that the insulating member 400 has a better insulation effect between the first empty foil area 212 and the packaging bag 100, reducing the possibility of corrosion and rupture of the packaging bag 100, and improving the safety of the battery cell 10.

[0100] See also Figure 3 and Fig. 9 In some embodiments, along the first direction X, the side where the first coating area 211 is connected to the first empty foil area 212 exceeds the second electrode 230, and the width of the exceeding portion is W3 mm, and the width of the second portion 420 is W4 mm, W4≤W3. For example, W4 can be W3, 0.9*W3, or 0.8*W3, etc.

[0101] Along the first direction X, the side where the first coated area 211 is connected to the first empty foil area 212 exceeds the second pole piece 230. Therefore, a step is formed on the side of the second pole piece 230 close to the first empty foil area 212 and the side where the first coated area 211 is connected to the first empty foil area 212. By making the width of the exceeding portion W3 mm and the width of the second portion 420 W4 mm, W4≤W3, the insulating member 400 does not overlap with the second pole piece 230, and at least part of the second portion 420 is located in the step in the thickness direction of the first pole piece 210. The second portion 420 does not exceed the second pole piece 230 in the thickness direction of the first pole piece 210 or the thickness of the portion exceeding the second pole piece 230 is small, so that the insulating member 400 has a small effect on the thickness of the electrode assembly 200, which is beneficial to improving the energy density of the battery cell 10.

[0102] In some embodiments, W4≤W3≤5 mm. For example, W3 may be 5 mm, W4 may be 5 mm, or W3 may be 5 mm, W4 may be 4 mm, or W3 may be 4 mm, W4 may be 3 mm, and so on.

[0103] By ensuring that W4≤W3≤5mm, the space occupied by the excess portion and the second portion 420 can be reduced, which is beneficial to improving the energy density of the battery cell 10; after the first coating area 211 expands, the insulating member 400 is less likely to act on the first empty foil area 212 and the first coating area 211 to cause local stress unevenness in the electrode assembly 200, thereby reducing the possibility of damage to the electrode assembly 200.

[0104] In some embodiments, the thickness of the first empty foil area 212 is H1 μm, the thickness of the insulating member 400 is H2 μm, and 2≤H2 / H1≤5. For example, H2 / H1 can be 2, 3, or 5.

[0105] When H2 / H1 is greater than or equal to 2, the insulating member 400 can be thicker than the first empty foil area 212, and the possibility of the burrs on the first empty foil area 212 piercing the insulating member 400 is small, thereby reducing the possibility of the burrs on the first empty foil area 212 contacting the packaging bag 100, reducing the possibility of the packaging bag 100 corroding and cracking, and further improving the safety of the battery cell 10; when H2 / H1 is less than or equal to 5, the first empty foil area 212 can provide sufficient support for the insulating member 400, reducing the possibility of the first empty foil area 212 being broken and damaged due to excessive pressure from the insulating member 400. possibility, thereby improving the reliability of the battery cell 10; therefore, when 2≤H2 / H1≤5, it can reduce the possibility that the burrs on the first empty foil area 212 pierce the insulating member 400, thereby reducing the possibility that the burrs on the first empty foil area 212 contact the packaging bag 100, reducing the possibility that the packaging bag 100 is corroded and cracked, and further improving the safety of the battery cell 10; it can also enable the first empty foil area 212 to provide sufficient supporting force for the insulating member 400, reducing the possibility that the insulating member 400 exerts excessive pressure on the first empty foil area 212 and causing the first empty foil area 212 to be broken and damaged, thereby improving the reliability of the battery cell 10.

[0106] See also Figure 7 In some embodiments, the insulating member 400 is disposed around the outermost first empty foil area 212. This makes the insulating member 400 occupy a smaller space, which is beneficial to improving the energy density of the battery cell 10.

[0107] See also Fig.10 , Fig.10 A schematic diagram of a partial structure of a battery cell provided in some embodiments of the present application.

[0108] In some other embodiments, the insulating member 400 is disposed around the outermost first empty foil area 212 for multiple turns.

[0109] By arranging the insulating member 400 around the outermost first empty foil area 212 for multiple turns, the insulating member 400 can provide better insulation effect between the first empty foil area 212 and the packaging bag 100 , further reducing the possibility of corrosion and rupture of the packaging bag 100 , and further improving the safety of the battery cell 10 .

[0110] See also Figure 3In some embodiments, the second electrode sheet 230 includes a second coated area 231 and a second empty foil area 232. Along the first direction X, the first empty foil area 212 and the second empty foil area 232 are respectively located at two ends of the electrode assembly 200. Along the length direction of the first electrode sheet 210 after unfolding, the length of the second empty foil area 232 is L3, the length of the second coated area 231 is L4, and 0.5≤L3 / L4≤1. For example, L3 / L4 can be 0.5, 0.7 or 1. The battery cell 10 includes a second electrical connector 600, one end of which is connected to the second empty foil area 232, and the other end of the second electrical connector 600 extends out of the packaging bag 100.

[0111] When L3 / L4 is greater than or equal to 0.5, the length of the first empty foil area 212 can be made longer, and the current carrying capacity of the first empty foil area 212 is higher, which is conducive to the rapid charge and discharge of the battery cell 10; when L3 / L4 is less than or equal to 1, it is convenient to prepare the first empty foil area 212; therefore, when 0.5≤L3 / L4≤1, it is possible to make the current carrying capacity of the first empty foil area 212 higher, which is conducive to the rapid charge and discharge of the battery cell 10, and it is convenient to prepare the first empty foil area 212. And when preparing the second empty foil area 232, there is no need to perform die cutting or only one die cutting is required. Compared with the battery cell 10 that is currently die cut multiple times to form multiple second empty foil areas 232, the preparation process of the battery cell 10 of the present application is simpler, which can improve the preparation efficiency of the battery cell 10 and reduce the preparation cost of the battery cell 10.

[0112] An embodiment of the present application provides an electrical device, comprising a battery cell 10 according to any of the above solutions, and the battery cell 10 is used to provide electrical energy to the electrical device.

[0113] The electrical device may be any of the aforementioned devices or systems using the battery cell 10 .

[0114] 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.

[0115] 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 is contained in the packaging bag, wherein the electrode assembly is formed by winding a first electrode sheet, a diaphragm, and a second electrode sheet which are stacked in layers; the first electrode sheet comprises a first coating area and a first empty foil area, and along a first direction, the first empty foil area is arranged on one side of the first coating area, and the first direction is parallel to the winding axis of the electrode assembly; along the length direction of the first electrode sheet after unfolding, the length of the first empty foil area is L1, and the length of the first coating area is L2, and 0.5≤L1 / L2≤1; a first electrical connector, one end of which is connected to the first empty foil area, and the other end of which extends out of the packaging bag; The insulating member is arranged on the outer surface of the outermost circle of the first empty foil area.

2. The battery cell according to claim 1, characterized in that: The electrode assembly includes a straight area and two bending areas. Along a second direction, the two bending areas are respectively located at two ends of the straight area. The second direction is perpendicular to the first direction.

3. The battery cell according to claim 2, characterized in that: The packaging bag comprises a main body and an edge sealing portion, the electrode assembly is accommodated in the main body, and the first electrical connector extends out of the packaging bag from the edge sealing portion; The battery core further comprises a sealing member, wherein the sealing member is used for sealingly connecting the first electrical connector and the edge sealing portion; Along the third direction, the projection of the insulating member does not overlap with the projection of the sealing member; The first direction, the second direction and the third direction are perpendicular to each other.

4. The battery cell according to claim 3, characterized in that: Along the first direction, the width of the insulating member is W1 mm, the width of the first empty foil area is W2 mm, the spacing distance between the sealing member and the first coating area is D1 mm, and W2≤W1≤D1.

5. The battery cell according to claim 4, characterized in that: 1≤D1 / W1≤1.5, and / or, 1≤W1 / W2≤2.

5.

6. The battery cell according to claim 4, characterized in that: 6mm≤W2≤18mm.

7. The battery cell according to claim 4, characterized in that: Along the first direction, the insulating member exceeds the first empty foil area.

8. The battery cell according to claim 2, characterized in that: The first empty foil area is wound into multiple turns, and the multiple turns of the first empty foil area are gathered along the third direction, and the angle between each turn of the first empty foil area located in the straight area and the first direction is θ, 0°≤θ≤60°; The first direction, the second direction and the third direction are perpendicular to each other.

9. The battery cell according to claim 1, characterized in that: The insulating member includes a first portion and a second portion, wherein the first portion is disposed in the first empty foil area, and the second portion is disposed in the first coating area.

10. The battery cell according to claim 9, characterized in that: Along the first direction, one side of the first coating area connected to the first empty foil area exceeds the second pole piece, and the width of the exceeding portion is W3 mm, and the width of the second portion is W4 mm, W4≤W3.

11. The battery cell according to claim 10, characterized in that: W4≤W3≤5mm.

12. The battery cell according to claim 1, characterized in that: The thickness of the first empty foil area is H1 μm, the thickness of the insulating member is H2 μm, and 2≤H2 / H1≤5.

13. The battery cell according to claim 1, characterized in that: The insulating member is arranged to wrap around the first empty foil area of ​​the outermost circle for multiple circles.

14. The battery cell according to claim 1, characterized in that: The second electrode sheet comprises a second coated area and a second empty foil area. Along the first direction, the first empty foil area and the second empty foil area are respectively located at two ends of the electrode assembly. Along the length direction of the first electrode sheet after unfolding, the length of the second empty foil area is L3, the length of the second coated area is L4, and 0.5≤L3 / L4≤1; The battery core comprises a second electrical connector, one end of the second electrical connector is connected to the second empty foil area, and the other end of the second electrical connector extends out of the packaging bag.

15. The battery cell according to claim 1, characterized in that: The packaging bag comprises an aluminum-plastic film, the first pole sheet is a negative pole sheet, and the second pole sheet is a positive pole sheet.

16. An electrical equipment, characterized in that: The invention comprises a battery cell as described in any one of claims 1 to 15, wherein the battery cell is used to provide electrical energy.

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