Battery cell and electric device

Abstract

The present application provides a battery cell and an electric device. The battery cell comprises a casing and an electrode assembly; the electrode assembly is accommodated in the casing; the casing comprises a first wall and a second wall arranged opposite to each other in the thickness direction of the battery cell; the first wall comprises a first sub-wall, a second sub-wall, and a first connecting wall; in a direction away from the second wall, the second sub-wall protrudes from the first sub-wall, and the first connecting wall connects the first sub-wall to the second sub-wall; in the thickness direction of the battery cell, the distance between the first sub-wall and the second sub-wall is H1, wherein 0 mm<H1≤1.5 mm; and the included angle between the first connecting wall and the thickness direction of the battery cell is θ1, wherein 0°<θ1≤45°. In this way, the casing can be better attached to the electrode assembly, so that the gap between the first connecting wall and the electrode assembly is smaller, thereby improving the energy density of the battery cell. Moreover, the electrode assembly does not easily shake in the casing, so that the stability of the battery cell is better.

Description

Battery cells and electrical equipment Cross-references to related applications

[0001] This application claims priority to Chinese patent application CN202411321134.3, filed on September 20, 2024, entitled “Battery Cell and Electrical Equipment”, the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of battery technology, and more specifically, to a battery cell and an electrical device. Background Technology

[0003] With the rapid development of new energy technologies, batteries have been widely used in electronic devices, electric vehicles, electric two-wheelers, power tools, and other fields. The requirements for battery quality, safety, and miniaturization are also becoming increasingly stringent.

[0004] For pouch batteries with stepped shapes, the packaging film is usually perforated to form the stepped shape. However, for some packaging films, especially those with shallow steps, it is difficult to perforate them. This results in poor adhesion between the outer shell and the electrode assembly after the packaging film is made into a shell. A large gap is formed between the steps of the outer shell and the electrode assembly, causing energy density loss in the battery. Furthermore, the electrode assembly is prone to shaking inside the shell, resulting in poor battery stability. Summary of the Invention

[0005] This application provides a battery cell and an electrical device that can improve the energy density and stability of the battery cell.

[0006] In a first aspect, this application provides a battery cell, which includes a housing and an electrode assembly housed within the housing. The housing includes a first wall and a second wall disposed opposite to each other along the thickness direction of the battery cell. The first wall includes a first sub-wall, a second sub-wall, and a first connecting wall. The second sub-wall protrudes from the first sub-wall in a direction away from the second wall, and the first connecting wall connects the first sub-wall and the second sub-wall. The distance between the first sub-wall and the second sub-wall along the thickness direction of the battery cell is H1, satisfying 0 mm < H1 ≤ 1.5 mm. The angle between the first connecting wall and the thickness direction of the battery cell is θ1, satisfying 0° < θ1 ≤ 45°.

[0007] In the above technical solution, by housing the electrode assembly within the outer casing, the outer casing provides protection for the electrode assembly. The outer casing includes a first wall and a second wall disposed opposite each other along the thickness direction of the battery cell. The first wall includes a first sub-wall, a second sub-wall, and a first connecting wall. The second sub-wall protrudes from the first sub-wall in a direction away from the second wall. The first connecting wall connects the first and second sub-walls, forming a stepped structure between them. This allows for the housing of other components when the battery cell is assembled into an electrical device. The distance H1 between the first and second sub-walls along the thickness direction of the battery cell satisfies 0mm < H1 ≤ 1.5mm. When the perforation depth of the packaging film is greater than 1.5mm, a small angle can be formed directly between the first connecting wall and the thickness direction of the battery cell, resulting in good adhesion between the outer casing and the electrode assembly. However, when the perforation depth of the packaging film is less than or equal to 1.5mm, it is difficult to form a small angle between the first connecting wall and the thickness direction of the battery cell, leading to poor adhesion between the outer casing and the electrode assembly. When θ1 is greater than 0°, it facilitates the installation of the electrode assembly into the housing, reducing the possibility of damage caused by compression between the electrode assembly and the housing during installation. When θ1 is less than or equal to 45°, the cell can be used in cases where the step depth is less than or equal to 1.5mm. Furthermore, when the step depth is less than or equal to 1.5mm, the angle θ1 between the first connecting wall and the thickness direction of the cell is smaller, resulting in better fit between the housing and the electrode assembly. This smaller gap between the first connecting wall and the electrode assembly improves the energy density of the cell and reduces the likelihood of the electrode assembly shaking within the housing, thus enhancing the cell's stability. Therefore, when 0° < θ1 ≤ 45°, it facilitates the installation of the electrode assembly into the housing, reducing the possibility of damage caused by compression between the electrode assembly and the housing during installation. It also improves the fit between the housing and the electrode assembly, reduces the gap between the first connecting wall and the electrode assembly, improves the energy density of the cell, and reduces the likelihood of the electrode assembly shaking within the housing, resulting in better cell stability.

[0008] In some embodiments of this application, 0mm < H1 ≤ 1mm, and 20° ≤ θ1 ≤ 45°.

[0009] In the above technical solution, when θ1 is greater than or equal to 20°, it facilitates the installation of the electrode assembly into the housing, reducing the possibility of damage caused by squeezing between the electrode assembly and the housing during installation. When θ1 is less than or equal to 45°, it further enables the battery cell to be applicable to cases where the step depth is less than or equal to 1mm, thus broadening the applicability of the battery cell. Furthermore, when the step depth is less than or equal to 1mm, the angle θ1 between the first connecting wall and the thickness direction of the battery cell is smaller, further improving the fit between the housing and the electrode assembly and reducing the gap between the first connecting wall and the electrode assembly. This is beneficial for further improving the energy density of the battery cell, and the electrode assembly is less prone to shaking within the housing, further enhancing the stability of the battery cell. Therefore, when 0mm < H1 ≤ 1mm and 20° ≤ θ1 ≤ 45°, it not only facilitates the installation of the electrode assembly into the housing, reducing the possibility of damage caused by squeezing between the electrode assembly and the housing during installation, but also further improves the fit between the housing and the electrode assembly, reduces the gap between the first connecting wall and the electrode assembly, further enhances the energy density of the battery cell, and reduces the likelihood of shaking within the housing, further enhancing the stability of the battery cell.

[0010] In some embodiments of this application, the electrode assembly includes a first electrode group and a second electrode group, which are stacked together. The size of the first electrode group along a first direction is larger than the size of the second electrode group along the first direction. The first electrode group is located between a first sub-wall and a second wall, and the second electrode group is located between the first electrode group and the second sub-wall. The first direction is perpendicular to the thickness direction of the battery cell.

[0011] In the above technical solution, by making the electrode assembly include a first electrode group and a second electrode group, the first electrode group and the second electrode group are stacked, and the size of the first electrode group along the first direction is larger than the size of the second electrode group along the first direction, so that the first electrode group and the second electrode group together form a stepped structure to fit the stepped structure of the shell; the first electrode group is located between the first sub-wall and the second wall, and the second electrode group is located between the first electrode group and the second sub-wall, so that the second electrode group is accommodated at the stepped structure of the shell to fit the first wall and the second wall of the shell.

[0012] In some embodiments of this application, the first sub-wall has a first end close to the first connecting wall, and the second electrode group includes a second positive electrode and a second negative electrode stacked together. Along the first direction, the distance between the end of the second negative electrode close to the first connecting wall and the first end is D, which satisfies D≤1.5mm.

[0013] In the above technical solution, the first sub-wall has a first end close to the first connecting wall, the second electrode assembly includes a second positive electrode plate and a second negative electrode plate stacked together, and along the first direction, the distance D between the end of the second negative electrode plate close to the first connecting wall and the first end satisfies D≤1.5 mm. This can make the gap between the first connecting wall and the electrode assembly smaller along the first direction, which is beneficial to improving the energy density of the battery cell, and can prevent the electrode assembly from shaking in the outer shell, resulting in better stability of the battery cell.

[0014] In some embodiments of the present application, along the thickness direction of the battery cell, the distance between the first sub-wall and the second wall is T1, and the distance between the second sub-wall and the second wall is T2, satisfying T1 < T2.

[0015] In the above technical solution, by making the distance T1 between the first sub-wall and the second wall and the distance T2 between the second sub-wall and the second wall satisfy T1 < T2 along the thickness direction of the battery cell, a stepped structure can be formed between the first sub-wall and the second sub-wall, which can be used to accommodate other components when the battery cell 10 is assembled in an electrical device, so as to adapt to different electrical devices.

[0016] In some embodiments of the present application, one end of the first connecting wall is connected to the first sub-wall through a first arc transition portion, and the other end of the first connecting wall is connected to the second sub-wall through a second arc transition portion. [[ID=,11]]

[0017] In the above technical solution, by making one end of the first connecting wall be connected to the first sub-wall through a first arc transition portion and the other end of the first connecting wall be connected to the second sub-wall through a second arc transition portion, it is convenient for the preparation and forming of the first wall, and the force distribution of the first arc transition portion and the second arc transition portion is more uniform when stressed, which is not easy to cause stress concentration. Therefore, the possibility of the first connecting wall being damaged by stress can be reduced, and it is not easy to damage other components.

[0018] In some embodiments of the present application, the first wall further includes a third sub-wall and a second connecting wall. The third sub-wall is located on the side of the second sub-wall away from the first sub-wall. Along the direction away from the second wall, the second sub-wall protrudes from the third sub-wall, and the second connecting wall connects the second sub-wall and the third sub-wall; along the thickness direction of the battery cell, the distance between the second sub-wall and the third sub-wall is H2, satisfying 0 mm < H2 ≤ 1.5 mm; the included angle between the second connecting wall and the thickness direction of the battery cell is θ2, satisfying 0° < θ2 ≤ 45°.

[0019] In the above technical solution, by including a third sub-wall and a second connecting wall in the first wall, the third sub-wall is located on the side of the second sub-wall away from the first sub-wall. Along the direction away from the second wall, the second sub-wall protrudes from the third sub-wall. The second connecting wall connects the second and third sub-walls, forming a stepped structure between them. This allows for the housing of other components when the battery cell is assembled into an electrical device. Furthermore, by ensuring that the distance between the second and third sub-walls along the thickness direction of the battery cell is H2, satisfying 0mm < H2 ≤ 1.5mm, when θ2 is greater than 0°, it facilitates the insertion of the electrode assembly into the housing, reducing the possibility of damage caused by pressure on the electrode assembly and housing during installation. When θ2 ≤ 45°, the battery cell is suitable for applications with a step depth less than or equal to 1.5mm. In cases where the step depth is less than or equal to 1.5 mm, the angle θ2 between the second connecting wall and the thickness direction of the battery cell is small, which allows for better fit between the outer casing and the electrode assembly. The gap between the second connecting wall and the electrode assembly is smaller, which is beneficial for improving the energy density of the battery cell. Furthermore, the electrode assembly is less likely to shake within the outer casing, resulting in better stability of the battery cell. Therefore, when 0° < θ2 ≤ 45°, it is not only easier to install the electrode assembly into the outer casing, reducing the possibility of damage to the electrode assembly and the outer casing during installation, but also allows for better fit between the outer casing and the electrode assembly. The gap between the second connecting wall and the electrode assembly is smaller, which is beneficial for improving the energy density of the battery cell. Furthermore, the electrode assembly is less likely to shake within the outer casing, resulting in better stability of the battery cell.

[0020] In some embodiments of this application, an insulating layer is provided between the first wall and the electrode assembly, and the insulating layer at least covers the inner surface of the first connecting wall.

[0021] In the above technical solution, by providing an insulating layer between the first wall and the electrode assembly, the insulating layer at least covers the inner surface of the first connecting wall, so that the insulating layer can play an insulating role between the outer shell and the electrode assembly, and can also play a protective role for the outer shell, thereby reducing the possibility of the electrode assembly damaging the first connecting wall.

[0022] Secondly, this application provides an electrical device including a battery cell as described above, the battery cell being used to provide electrical energy.

[0023] Thirdly, this application provides a method for preparing a battery cell, comprising:

[0024] A battery cell is provided, comprising a housing and an electrode assembly, the electrode assembly being housed within the housing; the housing includes a first wall and a second wall disposed opposite to each other along the thickness direction of the battery cell, the first wall including a first sub-wall, a second sub-wall, and a first connecting wall, the second sub-wall protruding from the first sub-wall along a direction away from the second wall, the first connecting wall connecting the first sub-wall and the second sub-wall; the distance between the first sub-wall and the second sub-wall along the thickness direction of the battery cell is H1, satisfying 0mm

[0025] The first connecting wall of the battery cell is shaped by a pressure block so that the angle θ1 between the first connecting wall and the thickness direction of the battery cell satisfies 0°<θ1≤45°.

[0026] In the above technical solution, by housing the electrode assembly within the outer casing, the outer casing provides protection for the electrode assembly. The outer casing includes a first wall and a second wall disposed opposite each other along the thickness direction of the battery cell. The first wall includes a first sub-wall, a second sub-wall, and a first connecting wall. The second sub-wall protrudes from the first sub-wall in a direction away from the second wall. The first connecting wall connects the first and second sub-walls, forming a stepped structure between them. This allows for the housing of other components when the battery cell is assembled into an electrical device. The distance H1 between the first and second sub-walls along the thickness direction of the battery cell satisfies 0mm < H1 ≤ 1.5mm. When θ1 is greater than 0°, it facilitates the insertion of the electrode assembly into the outer casing, reducing the possibility of damage caused by pressure between the electrode assembly and the outer casing during installation. When θ1 is less than or equal to 45°, it facilitates the insertion of the electrode assembly into the outer casing, reducing the possibility of damage caused by pressure between the electrode assembly and the outer casing during installation. The battery cell is suitable for applications with a step depth of less than or equal to 1.5 mm. When the step depth is less than or equal to 1.5 mm, the angle θ1 between the first connecting wall and the thickness direction of the battery cell is small, resulting in better fit between the outer casing and the electrode assembly. The smaller gap between the first connecting wall and the electrode assembly improves the energy density of the battery cell, and the electrode assembly is less prone to shaking within the casing, thus enhancing the stability of the battery cell. Therefore, when 0° < θ1 ≤ 45°, it facilitates the installation of the electrode assembly into the outer casing, reducing the possibility of damage during installation. It also improves the fit between the outer casing and the electrode assembly, further reducing the gap between the first connecting wall and the electrode assembly, which in turn improves the energy density of the battery cell. Furthermore, the electrode assembly is less prone to shaking within the casing, resulting in better stability of the battery cell. Attached Figure Description

[0027] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly described below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings.

[0028] ​Figure 1 is a structural schematic diagram of a battery cell provided in some embodiments of this application from one perspective;

[0029] Figure 2 is a schematic cross-sectional view of the battery cell shown in Figure 1 along line AA;

[0030] Figure 3 is a partially enlarged structural diagram of point B in the battery cell shown in Figure 2;

[0031] Figure 4 is a structural schematic diagram of a battery cell provided in some other embodiments of this application from one perspective;

[0032] Figure 5 is a schematic cross-sectional view of the battery cell shown in Figure 4 along CC.

[0033] Figure 6 is a partially enlarged structural diagram of point D in the battery cell shown in Figure 5;

[0034] Figure 7 is a schematic flowchart of a method for preparing a battery cell according to some embodiments of this application;

[0035] Figure 8 is a partially enlarged structural diagram of the battery cell before shaping, provided in some embodiments of this application;

[0036] Figure 9 is a three-dimensional structural diagram of the shaping device and battery cell provided in some embodiments of this application.

[0037] Icons: 10 - Cell; 100 - Casing; 110 - First wall; 111 - First sub-wall; 112 - Second sub-wall; 113 - First connecting wall; 1131 - First main body; 1132 - First arc transition section; 1133 - Second arc transition section; 114 - Third sub-wall; 115 - Second connecting wall; 1151 - Second main body; 1152 - Third transition section; 1153 - Fourth transition section; 120 - Second wall ; 130 - Insulating layer; 140 - First sealing part; 150 - Second sealing part; 200 - Electrode assembly; 210 - First electrode group; 211 - First positive electrode; 212 - First negative electrode; 220 - Second electrode group; 221 - Second positive electrode; 222 - Second negative electrode; 230 - First electrical connector; 240 - Second electrical connector; X - Thickness direction of the battery cell; Y - First direction; Z - Second direction. Specific embodiment.

[0038] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions in the embodiments of this application will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application are within 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 commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used in the specification of this application is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms "comprising" and "having" and any variations thereof in the specification, claims and foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0040] The terms "first," "second," etc., in the specification, claims, or the accompanying drawings of this application are used to distinguish different objects, rather than to describe a specific order or primary / secondary relationship.

[0041] In this application, the reference to "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment that is mutually exclusive with other embodiments.

[0042] In the embodiments of this application, the same reference numerals denote the same components, and for the sake of brevity, detailed descriptions of the same components are omitted in different embodiments. It should be understood that the thickness, length, width, and other dimensions of various components in the embodiments of this application shown in the accompanying drawings, as well as the overall thickness, length, width, and other dimensions of the integrated device, are merely illustrative and should not constitute any limitation on this application.

[0043] With the development of the new energy industry, batteries are gradually moving towards higher energy density, higher power density, and more multifunctionality. Some electrical devices require adaptation to irregularly shaped battery cells. For example, devices with foldable screens need to be compatible with battery cells that have stepped surfaces to allow for the installation of circuit boards and other components at the stepped areas.

[0044] In stepped-shaped pouch cells, the outer shell is typically formed by perforating the packaging film. The first wall of the outer shell forms a first sub-wall, a second sub-wall, and a first connecting wall. The second sub-wall protrudes from the first sub-wall, and the first connecting wall connects the first and second sub-walls, forming a stepped structure between them. However, for some packaging films, especially those with shallow steps, the angle between the first connecting wall and the cell's thickness direction after perforation is large, making it difficult to form the perforation. This results in poor adhesion between the outer shell and the electrode assembly, creating a large gap between the stepped areas of the outer shell and the electrode assembly. This leads to energy density loss in the battery, and the electrode assembly is prone to movement within the outer shell, resulting in poor battery stability.

[0045] To improve the energy density and stability of the battery cell, this application provides a battery cell including a housing and an electrode assembly housed in the housing. The housing includes a first wall and a second wall disposed opposite to each other along the thickness direction of the battery cell. The first wall includes a first sub-wall, a second sub-wall, and a first connecting wall. The second sub-wall protrudes from the first sub-wall in a direction away from the second wall. The first connecting wall connects the first sub-wall and the second sub-wall. The distance between the first sub-wall and the second sub-wall along the thickness direction of the battery cell is H1, satisfying 0 mm < H1 ≤ 1.5 mm. The angle between the first connecting wall and the thickness direction of the battery cell is θ1, satisfying 0° < θ1 ≤ 45°.

[0046] In this type of battery cell housing, the electrode assembly is housed within the outer casing, which then protects the electrode assembly. The outer casing includes a first wall and a second wall disposed opposite each other along the thickness direction of the battery cell. The first wall includes a first sub-wall, a second sub-wall, and a first connecting wall. The second sub-wall protrudes from the first sub-wall in a direction away from the second wall. The first connecting wall connects the first and second sub-walls, forming a stepped structure between them. This allows for the housing of other components when the battery cell is assembled into an electrical device. The distance H1 between the first and second sub-walls along the thickness direction of the battery cell satisfies 0mm < H1 ≤ 1.5mm. When θ1 is greater than 0°, it facilitates the insertion of the electrode assembly into the outer casing, reducing the possibility of damage during installation due to pressure between the electrode assembly and the outer casing. When θ1 is less than or equal to 45°... This design allows the battery cell to be used when the step depth is less than or equal to 1.5 mm. Furthermore, when the step depth is less than or equal to 1.5 mm, the angle θ1 between the first connecting wall and the thickness direction of the battery cell is smaller, resulting in better fit between the casing and the electrode assembly. The smaller gap between the first connecting wall and the electrode assembly improves the energy density of the battery cell and reduces the likelihood of the electrode assembly shaking within the casing, thus enhancing the battery cell's stability. Therefore, when 0° < θ1 ≤ 45°, it facilitates the installation of the electrode assembly into the casing, reducing the possibility of damage during installation. It also improves the fit between the casing and the electrode assembly, further reducing the gap between the first connecting wall and the electrode assembly, which in turn improves the energy density of the battery cell. The smaller gap also reduces the likelihood of the electrode assembly shaking within the casing, resulting in better battery cell stability.

[0047] The battery cell provided in this application embodiment can be a secondary battery or a primary battery, such as a lithium-ion battery, a sodium-ion battery, or a magnesium-ion battery, etc., and this application embodiment is not limited in this respect. The electrochemical device can be cylindrical, flat, cuboid, or other shapes, etc., and this application embodiment is not limited in this respect either.

[0048] This application provides an electrical device that uses battery cells as a power source. The electrical device can be, but is not limited to, mobile phones, tablets, laptops, electric toys, power tools, electric vehicles, electric cars, ships, spacecraft, etc.

[0049] Referring to Figures 1 to 3, Figure 1 is a structural schematic diagram of a battery cell provided in some embodiments of this application from one perspective; Figure 2 is a cross-sectional structural schematic diagram of the battery cell shown in Figure 1 along AA; and Figure 3 is a partially enlarged structural schematic diagram of point B of the battery cell shown in Figure 2.

[0050] This application provides a battery cell 10, which includes a housing 100 and an electrode assembly 200, with the electrode assembly 200 housed in the housing 100.

[0051] By housing the electrode assembly 200 within the housing 100, the housing 100 can protect the electrode assembly 200.

[0052] The battery cell 10 includes a casing 100, an electrode assembly, and an electrolyte. The casing 100 houses the electrode assembly and the electrolyte. The electrode assembly consists of a positive electrode, a negative electrode, and a separator. The battery cell 10 primarily operates by the movement of metal ions between the positive and negative electrode plates. The positive electrode 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 portion of the positive current collector without the positive active material layer serves as the positive electrode tab, through which electrical energy is input or output. The positive electrode tab and the positive current collector can also be separate components that are then connected as a single unit, for example, by welding or using conductive adhesive. Taking a lithium-ion battery 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 materials, or lithium manganese oxide, etc. The negative electrode comprises 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 portion of the negative current collector without the negative active material layer serves as the negative electrode tab, through which electrical energy is input or output. The negative electrode tab and the negative current collector can also be separate components that are then connected as a single unit, for example, by welding or using conductive adhesive. The negative current collector can be made of copper, and the negative active material can be made of carbon or silicon, etc. The separator can be made of polypropylene (PP) or polyethylene (PE), etc. The electrolyte can include organic solvents, lithium salts, etc.

[0053] In some embodiments, the electrode assembly can be a stacked electrode assembly, in which at least one positive electrode, at least one negative electrode, and at least one separator are stacked in a certain order. The separator is disposed between the positive electrode and the negative electrode to insulate and separate the positive electrode and the negative electrode, thereby reducing the risk of short circuit in the cell 10.

[0054] In some embodiments, the electrode assembly can also be a wound electrode assembly. A positive electrode, a negative electrode, and a separator are stacked in a specific order and wound around a central axis to form a wound electrode assembly. The separator is disposed between the positive and negative electrode sheets, and serves to insulate and separate the positive and negative electrode sheets.

[0055] In some embodiments, the housing 100 may be made of aluminum-plastic film.

[0056] In some embodiments, the housing 100 includes a first wall 110 and a second wall 120 disposed opposite to each other along the thickness direction X of the battery cell. The first wall 110 includes a first sub-wall 111, a second sub-wall 112 and a first connecting wall 113. Along a direction away from the second wall 120, the second sub-wall 112 protrudes from the first sub-wall 111, and the first connecting wall 113 connects the first sub-wall 111 and the second sub-wall 112.

[0057] By making the housing 100 include a first wall 110 and a second wall 120 disposed opposite to each other along the thickness direction X of the battery cell, the first wall 110 includes a first sub-wall 111, a second sub-wall 112 and a first connecting wall 113, the second sub-wall 112 protrudes from the first sub-wall 111 in a direction away from the second wall 120, and the first connecting wall 113 connects the first sub-wall 111 and the second wall 112, such that a stepped structure is formed between the first sub-wall 111 and the second wall 112, which can be used to accommodate other components when the battery cell 10 is assembled into an electrical device.

[0058] In some embodiments, along the thickness direction X of the battery cell, the distance between the first sub-wall 111 and the second sub-wall 112 is H1, satisfying 0 mm < H1 ≤ 1.5 mm. For example, H1 can be 1.5 mm, 1.2 mm, or 1 mm. The angle between the first connecting wall 113 and the thickness direction X of the battery cell is θ1, satisfying 0° < θ1 ≤ 45°. For example, θ1 can be 45°, 40°, or 35°, etc.

[0059] When θ1 is greater than 0°, it facilitates the insertion of the electrode assembly 200 into the housing 100, reducing the possibility of damage caused by compression between the electrode assembly 200 and the housing 100 during installation. When θ1 ≤ 45°, the battery cell 10 is suitable for applications with a step depth less than or equal to 1.5 mm. Furthermore, when the step depth is less than or equal to 1.5 mm, the angle θ1 between the first connecting wall 113 and the thickness direction X of the battery cell is smaller, resulting in better fit between the housing 100 and the electrode assembly 200. The smaller gap between the first connecting wall 113 and the electrode assembly 200 also helps improve the energy density of the battery cell 10. The electrode assembly 200 is less likely to shake within the housing 100, resulting in better stability of the battery cell 10. Therefore, when 0° < θ1 ≤ 45°, it is not only easier for the electrode assembly 200 to be installed into the housing 100, reducing the possibility of damage to the electrode assembly 200 and the housing 100 during installation, but also allows for better fit between the housing 100 and the electrode assembly 200, resulting in a smaller gap between the first connecting wall 113 and the electrode assembly 200. This is beneficial for improving the energy density of the battery cell 10, and the electrode assembly 200 is less likely to shake within the housing 100, resulting in better stability of the battery cell 10.

[0060] In some embodiments, the first connecting wall 113 includes a first main body portion 1131, a first transition portion, and a second transition portion. The surface of the first main body portion 1131 is planar. The first transition portion is connected to the first sub-wall 111, and the second transition portion is connected to the second sub-wall 112. The angle θ1 between the first connecting wall 113 and the thickness direction X of the battery cell is the angle between the plane where the first main body portion 1131 is located and the direction along the thickness direction X of the battery cell from the second wall 120 toward the first wall 110.

[0061] In some embodiments, 0mm < H1 ≤ 1mm. For example, H1 can be 1mm, 0.8mm, or 0.7mm, etc.

[0062] In some embodiments, 20° ≤ θ1 ≤ 45°. For example, θ1 can be 20°, 30°, or 45°, etc.

[0063] When θ1 is greater than or equal to 20°, it facilitates the insertion of the electrode assembly 200 into the housing 100, reducing the possibility of damage caused by compression between the electrode assembly 200 and the housing 100 during installation. When θ1 is less than or equal to 45°, it further enables the battery cell 10 to be applicable to cases where the step depth is less than or equal to 1 mm, thus broadening the applicability of the battery cell 10. Furthermore, when the step depth is less than or equal to 1 mm, the angle θ1 between the first connecting wall 113 and the thickness direction of the battery cell 10 is smaller, further improving the fit between the housing 100 and the electrode assembly 200 and reducing the gap between the first connecting wall 113 and the electrode assembly 200, which is beneficial for further improving the performance of the battery cell 10. The energy density is improved, and the electrode assembly 200 is less prone to shaking within the housing 100, further enhancing the stability of the battery cell 10. Therefore, when 0mm < H1 ≤ 1mm and 20° ≤ θ1 ≤ 45°, it is not only easier for the electrode assembly 200 to be installed into the housing 100, reducing the possibility of damage to the electrode assembly 200 and the housing 100 during installation, but it also further improves the fit between the housing 100 and the electrode assembly 200, resulting in a smaller gap between the first connecting wall 113 and the electrode assembly 200. This is beneficial for further improving the energy density of the battery cell 10, and the electrode assembly 200 is less prone to shaking within the housing 100, further enhancing the stability of the battery cell 10.

[0064] In some embodiments, the electrode assembly 200 includes a first electrode group 210 and a second electrode group 220, which are stacked together. The dimension of the first electrode group 210 along the first direction Y is larger than the dimension of the second electrode group 220 along the first direction Y. The first electrode group 210 is located between a first sub-wall 111 and a second wall 120, and the second electrode group 220 is located between the first electrode group 210 and the second sub-wall 112.

[0065] The first direction, Y, is perpendicular to the thickness direction X of the battery cell.

[0066] By making the electrode assembly 200 include a first electrode group 210 and a second electrode group 220, with the first electrode group 210 and the second electrode group 220 stacked, and the size of the first electrode group 210 along the first direction Y being larger than the size of the second electrode group 220 along the first direction Y, the first electrode group 210 and the second electrode group 220 can jointly form a stepped structure to adapt to the stepped structure of the housing 100; the first electrode group 210 is located between the first sub-wall 111 and the second wall 120, and the second electrode group 220 is located between the first electrode group 210 and the second sub-wall 112, so that the second electrode group 220 is accommodated at the stepped structure of the housing 100 to adapt to the first wall 110 and the second wall 120 of the housing 100.

[0067] In some embodiments, the first electrode group 210 includes a plurality of first positive electrode plates 211 and a plurality of first negative electrode plates 212 stacked together, resulting in a high energy density for the first electrode group 210.

[0068] In some other embodiments, the first electrode group 210 may include a first positive electrode 211 and a first negative electrode 212 stacked together.

[0069] In some embodiments, the first sub-wall 111 has a first end near the first connecting wall 113, and the second electrode group 220 includes a second positive electrode 221 and a second negative electrode 222 stacked together. Along the first direction Y, the distance between the end of the second negative electrode 222 near the first connecting wall 113 and the first end is D, which satisfies D≤1.5mm. For example, D can be 1.5mm, 1.2mm, or 1mm, etc.

[0070] The first sub-wall 111 has a first end close to the first connecting wall 113. The second electrode group 220 includes a second positive electrode 221 and a second negative electrode 222 stacked together. Along the first direction Y, the distance D between the end of the second negative electrode 222 close to the first connecting wall 113 and the first end satisfies D≤1.5mm. This makes the gap between the first connecting wall 113 and the electrode assembly 200 smaller along the first direction Y, which is beneficial to improving the energy density of the cell 10 and makes the electrode assembly 200 less prone to shaking within the outer casing 100, resulting in better stability of the cell 10.

[0071] In some embodiments, the second electrode group 220 may include a second positive electrode 221 and a second negative electrode 222 stacked together, such that the thickness of the second electrode group 220 is small and can be accommodated between the first electrode group 210 and the second sub-wall 112.

[0072] In other embodiments, the second electrode group 220 may also include a plurality of second positive electrode plates 221 and a plurality of second negative electrode plates 222 stacked together, so that the energy density of the second electrode group 220 is higher.

[0073] In some embodiments, along the thickness direction X of the battery cell, the distance between the first sub-wall 111 and the second wall 120 is T1, and the distance between the second sub-wall 112 and the second wall 120 is T2, satisfying T1 < T2. For example, T1 can be 0.9*T2, 0.7*T2, or 0.5*T2, etc.

[0074] By ensuring that the distance T1 between the first sub-wall 111 and the second wall 120 and the distance T2 between the second sub-wall 112 and the second wall 120 along the thickness direction X of the battery cell satisfy T1 < T2, a stepped structure can be formed between the first sub-wall 111 and the second sub-wall 112. This structure can be used to accommodate other components when the battery cell 1010 is assembled into an electrical device, thus adapting to different electrical devices.

[0075] In some embodiments, the surface of the second wall 120 is planar, such that the housing 100 forms a stepped structure only on one side of the cell in the thickness direction X, to accommodate the electrical equipment.

[0076] In some embodiments, one end of the first connecting wall 113 is connected to the first sub-wall 111 via a first arc transition portion 1132, and the other end of the first connecting wall 113 is connected to the second sub-wall 112 via a second arc transition portion 1133.

[0077] By connecting one end of the first connecting wall 113 to the first sub-wall 111 via the first arc transition portion 1132, and connecting the other end of the first connecting wall 113 to the second sub-wall 112 via the second arc transition portion 1133, it is easier to prepare and form the first wall 110. Furthermore, the force distribution of the first arc transition portion 1132 and the second arc transition portion 1133 is more uniform when subjected to force, making it less likely to cause stress concentration. This reduces the possibility of the first connecting wall 113 breaking under stress and also makes it less likely to damage other components.

[0078] Referring to Figures 4 to 6, Figure 4 is a structural schematic diagram of a battery cell provided in some other embodiments of this application from one perspective; Figure 5 is a cross-sectional structural schematic diagram of the battery cell shown in Figure 4 along CC; and Figure 6 is a partially enlarged structural schematic diagram of the battery cell shown in Figure 5 at point D.

[0079] In some embodiments, the first wall 110 further includes a third sub-wall 114 and a second connecting wall 115. The third sub-wall 114 is located on the side of the second sub-wall 112 away from the first sub-wall 111. The second sub-wall 112 protrudes from the third sub-wall 114 in a direction away from the second wall 120. The second connecting wall 115 connects the second sub-wall 112 and the third sub-wall 114.

[0080] By including a third sub-wall 114 and a second connecting wall 115 in the first wall 110, the third sub-wall 114 is located on the side of the second sub-wall 112 away from the first sub-wall 111. The second sub-wall 112 protrudes from the third sub-wall 114 in a direction away from the second wall 120. The second connecting wall 115 connects the second sub-wall 112 and the third sub-wall 114, forming a stepped structure between the second sub-wall 112 and the third sub-wall 114, which can be used to accommodate other components when the battery cell 10 is assembled in an electrical device.

[0081] In some embodiments, the distance between the second sub-wall 112 and the third sub-wall 114 along the thickness direction X of the battery cell is H2, satisfying 0 mm < H2 ≤ 1.5 mm. For example, H2 can be 1.5 mm, 1.2 mm, or 1 mm. The angle between the second connecting wall 115 and the thickness direction X of the battery cell is θ2, satisfying 0° < θ2 ≤ 45°. For example, θ2 can be 45°, 40°, or 35°, etc.

[0082] When θ2 is greater than 0°, it facilitates the insertion of the electrode assembly 200 into the housing 100, reducing the possibility of damage caused by compression between the electrode assembly 200 and the housing 100 during installation. When θ2 is less than or equal to 45°, the battery cell 10 can be used when the step depth is less than or equal to 1.5 mm. Furthermore, when the step depth is less than or equal to 1.5 mm, the angle θ2 between the second connecting wall 115 and the thickness direction X of the battery cell is smaller, resulting in better fit between the housing 100 and the electrode assembly 200. The smaller gap between the second connecting wall 115 and the electrode assembly 200 also helps improve the energy efficiency of the battery cell 10. The electrode assembly 200 is less likely to shake within the housing 100, resulting in better stability of the battery cell 10. Therefore, when 0° < θ2 ≤ 45°, it is not only easier for the electrode assembly 200 to be installed into the housing 100, reducing the possibility of damage to the electrode assembly 200 and the housing 100 during installation, but also allows for better fit between the housing 100 and the electrode assembly 200, and a smaller gap between the second connecting wall 115 and the electrode assembly 200, which is beneficial to improving the energy density of the battery cell 10. Furthermore, the electrode assembly 200 is less likely to shake within the housing 100, resulting in better stability of the battery cell 10.

[0083] In some embodiments, the second connecting wall 115 includes a second main body portion 1151, a third transition portion 1152, and a fourth transition portion 1153. The surface of the second main body portion 1151 is planar. The third transition portion 1152 is connected to the third sub-wall 114, and the fourth transition portion 1153 is connected to the second sub-wall 112. The angle θ1 between the second connecting wall 115 and the thickness direction X of the battery cell is the angle between the plane containing the second main body portion 1151 and the direction along the thickness direction X of the battery cell from the second wall 120 toward the first wall 110.

[0084] In some embodiments, 0mm < H2 ≤ 1mm. For example, H2 can be 1mm, 0.8mm, or 0.7mm, etc.

[0085] In some embodiments, 20° ≤ θ2 ≤ 45°. For example, θ2 can be 20°, 30°, or 45°, etc.

[0086] By ensuring that 0mm < H1 ≤ 2mm and 20° ≤ θ2 ≤ 45°, the battery cell 10 can be further made suitable for cases where the step depth is less than or equal to 1mm, thus broadening the applicability of the battery cell 10. Furthermore, when the step depth is less than or equal to 1mm, the angle θ2 between the second connecting wall 115 and the thickness direction X of the battery cell is smaller, which further improves the fit between the outer shell 100 and the electrode assembly 200 and reduces the gap between the second connecting wall 115 and the electrode assembly 200. This is beneficial for further improving the energy density of the battery cell 10, and the electrode assembly 200 is less prone to shaking within the outer shell 100, further enhancing the stability of the battery cell 10.

[0087] In some embodiments, an insulating layer 130 is provided between the first wall 110 and the electrode assembly 200, and the insulating layer 130 at least covers the inner surface of the first connecting wall 113.

[0088] By providing an insulating layer 130 between the first wall 110 and the electrode assembly 200, the insulating layer 130 at least covers the inner surface of the first connecting wall 113, so that the insulating layer 130 can serve as an insulation between the outer shell 100 and the electrode assembly 200, and can also serve as a protection for the outer shell 100, thereby reducing the possibility of the electrode assembly 200 damaging the first connecting wall 113.

[0089] In some embodiments, the insulating layer 130 may cover the inner surface of the first wall 110. This allows the insulating layer 130 to serve as insulation between the housing 100 and the electrode assembly 200, and also to protect the housing 100, thereby reducing the possibility of the electrode assembly 200 damaging the first wall 110.

[0090] In some embodiments, the insulating layer 130 may cover the inner surface of the housing 100. This allows the insulating layer 130 to serve as insulation between the housing 100 and the electrode assembly 200, and also to protect the housing 100, reducing the possibility of the electrode assembly 200 damaging the housing 100.

[0091] In some embodiments, the insulating layer 130 may include at least one of ethylene, propylene, vinylidene fluoride, acrylic acid, acrylate, styrene, acrylonitrile, maleic anhydride, vinyl chloride, and propylene chloride.

[0092] In some embodiments, the housing 100 includes a first sealing portion 140 and a second sealing portion 150, which are disposed opposite to each other along a first direction Y. The first sealing portion 140 is bent toward the electrode assembly 200, and the second sealing portion 150 is bent toward the electrode assembly 200, which can make the housing 100 occupy less space and is beneficial to improving the energy density of the battery cell 10.

[0093] In some embodiments, along the thickness direction X of the cell, the first sealing portion 140 does not extend beyond the first wall 110, and the second sealing portion 150 does not extend beyond the first wall 110, so that the first sealing portion 140 and the second sealing portion 150 have a smaller impact on the overall thickness of the cell 10, which is beneficial to improving the energy density of the cell 10.

[0094] Referring to Figure 1, in some embodiments, the battery cell 10 includes a first electrical connector 230 and a second electrical connector 240. The first electrical connector 230 is connected to the positive electrode tab of the electrode assembly 200, and the second electrical connector 240 is connected to the negative electrode tab of the electrode assembly 200 and extends out of the outer casing 100 along the second direction Y.

[0095] In some embodiments, the thickness direction X, the first direction Y, and the second direction Z of the battery cell are perpendicular to each other.

[0096] In some embodiments, the first electrical connector 230 and the positive electrode tab can be welded together, and the second electrical connector 240 and the negative electrode tab can be welded together.

[0097] In other embodiments, the first electrical connector 230 and the positive electrode tab can be integrally formed, and the second electrical connector 240 and the negative electrode tab can be integrally formed.

[0098] In some embodiments, the first electrical connector 230 and the second electrical connector 240 may be made of materials with good electrical conductivity, such as metals like lead or copper.

[0099] In other embodiments, the first electrical connector 230 and the second electrical connector 240 may extend out of the housing 100 along the first direction Y.

[0100] Along the first direction Y, the first electrical connector 230 and the second electrical connector 240 are located on the same side of the electrode assembly 200, and the first electrical connector 230 and the first sub-wall 111 are located on opposite sides of the electrode assembly 200.

[0101] Referring to Table 1, H1 is the distance between the first sub-wall 111 and the second sub-wall 112 along the thickness direction X of the battery cell; θ1 is the angle between the first connecting wall 113 and the thickness direction X of the battery cell; D is the distance between the end of the second negative electrode 222 near the first connecting wall 113 and the first end of the first sub-wall 111 near the first connecting wall 113 along the first direction Y; S is the area of ​​the cavity 201 formed by the plane containing the end face of the first connecting wall 113, the end face of the second negative electrode 222 near the first connecting wall 113, and the plane containing the inner surface of the first sub-wall 111.

[0102] When the perforation depth of the packaging film is greater than 1.5 mm, a small angle can be formed directly between the first connecting wall and the thickness direction of the battery cell, resulting in better adhesion between the outer casing and the electrode assembly. However, when the perforation depth of the packaging film is less than or equal to 1.5 mm, it is difficult to form a small angle between the first connecting wall and the thickness direction of the battery cell, leading to poorer adhesion between the outer casing and the electrode assembly. Therefore, Table 1 provided in this application only shows comparative examples with H1 ≤ 1.5 mm.

[0103] The measurement methods for the parameters in Table 1 are as follows:

[0104] (1) H1 is the measured distance from the inner surface of the second wall 120 to the inner surface of the first wall 110 along the thickness direction X of the cell.

[0105] (2) θ1 is the measured angle between the plane where the first main body 1131 of the first connecting wall 131 is located and the direction from the second wall 120 toward the first wall 110 in the thickness direction X of the battery cell.

[0106] (3) D is the measured distance between the plane of the second negative electrode plate 222 near the first connecting wall 113 along the first direction Y and the first end of the first sub-wall 111 near the first connecting wall 113 (i.e. the bending start end of the first connecting wall 113).

[0107] (4) S is the area of ​​the cavity 201 formed by the plane of the first connecting wall 113, the plane of the end face of the second negative electrode plate 222 near the first connecting wall 113, and the plane of the inner surface of the first wall 110. It is approximately a right triangle and can be obtained by the side length D of the cavity 201 along the first direction Y and the side length H1 of the cavity 201 along the thickness direction X of the cell, i.e. S = 1 / 2 * (H1 * D).

[0108] Table 1. Measurement of the distance between the electrode assembly and the housing.

[0109] Based on Table 1, the following conclusions can be drawn:

[0110] 1. Referring to Comparative Example 1 and Examples 1-4, Comparative Example 2 and Examples 5-8, and Comparative Example 3 and Examples 9-12, when θ1 is greater than 45°, the distance between the first connecting wall 113 and the second negative electrode plate 222 along the first direction Y is large, which will result in poor adhesion between the outer shell 100 and the electrode assembly 200. The electrode assembly 200 is prone to shaking inside the outer shell 100, affecting the stability of the cell 10. Furthermore, the area of ​​the cavity 201 is large, which will cause waste of the internal space of the cell 10 and affect the energy density of the cell 10.

[0111] When θ1 is less than or equal to 45°, the distance between the first connecting wall 113 and the second negative electrode plate 222 along the first direction Y is small, which makes the fit between the outer shell 100 and the electrode assembly 200 better, the electrode assembly 200 is less likely to shake inside the outer shell 100, and the stability of the cell 10 is better; and the area of ​​the cavity 201 is small, which is beneficial to improving the energy density of the cell 10.

[0112] 2. Referring to Examples 1-4, when the electrode assembly 200 is installed into the housing 100, there needs to be a certain space between the housing 100 and the electrode assembly 200. Otherwise, it is easy to cause difficulties in installing the electrode assembly 200 and the housing 100, and it is easy to cause the housing 100 or the electrode assembly 200 to be squeezed and damaged. When D is greater than 0.4mm, it is easier for the electrode assembly 200 to be installed into the housing 100. Therefore, when 20°≤θ1≤45°, it is not only easy for the electrode assembly 200 to be installed into the housing 100, but also the fit between the housing 100 and the electrode assembly 200 is better. The electrode assembly 200 is not easy to shake inside the housing 100, and the stability of the cell 10 is better. In addition, the area of ​​the cavity 201 is small, which is beneficial to improving the energy density of the cell 10.

[0113] This application provides an electrical device, including a battery cell 10 according to any of the above schemes, the battery cell 10 being used to provide electrical energy to the electrical device.

[0114] The electrical equipment can be any of the aforementioned devices or systems using battery cell 10.

[0115] Referring to Figure 7, which is a schematic flowchart of a method for preparing a battery cell according to some embodiments of this application.

[0116] This application provides a method for preparing a battery cell 10, including:

[0117] S11. A battery cell 10 is provided. The battery cell 10 includes a housing 100 and an electrode assembly 200. The electrode assembly 200 is housed in the housing 100. The housing 100 includes a first wall 110 and a second wall 120 disposed opposite to each other along the thickness direction X of the battery cell. The first wall 110 includes a first sub-wall 111, a second sub-wall 112, and a first connecting wall 113. Along a direction away from the second wall 120, the second sub-wall 112 protrudes from the first sub-wall 111. The first connecting wall 113 connects the first sub-wall 111 and the second sub-wall 112. Along the thickness direction X of the battery cell, the distance between the first sub-wall 111 and the second sub-wall 112 is H1, which satisfies 0mm < H1 ≤ 1.5mm.

[0118] S12. The first connecting wall 113 of the battery cell 10 is shaped by the pressure block so that the angle θ1 between the first connecting wall 113 and the thickness direction X of the battery cell satisfies 0°<θ1≤45°.

[0119] By housing the electrode assembly 200 within the housing 100, the housing 100 provides protection for the electrode assembly 200. The housing 100 includes a first wall 110 and a second wall 120 disposed opposite each other along the thickness direction X of the battery cell. The first wall 110 includes a first sub-wall 111, a second sub-wall 112, and a first connecting wall 113. The second sub-wall 112 protrudes from the first sub-wall 111 in a direction away from the second wall 120, and the first connecting wall 113 connects the first sub-wall 111 and the second sub-wall. 112, so that a stepped structure is formed between the first sub-wall 111 and the second sub-wall 112, which can be used to accommodate other components when the battery cell 10 is assembled into an electrical device; by making the distance H1 between the first sub-wall 111 and the second sub-wall 112 along the thickness direction X of the battery cell satisfy 0mm < H1 ≤ 1.5mm; when θ1 is greater than 0°, it is convenient to install the electrode assembly 200 into the housing 100, reducing the possibility of the electrode assembly 200 and the housing 100 being squeezed and damaged during installation; when θ1 is less than or equal to 4 The angle θ1 is 5°, which allows the battery cell 10 to be used when the step depth is less than or equal to 1.5 mm. When the step depth is less than or equal to 1.5 mm, the angle θ1 between the first connecting wall 113 and the thickness direction X of the battery cell is small, which makes the fit between the outer shell 100 and the electrode assembly 200 better. The gap between the first connecting wall 113 and the electrode assembly 200 is smaller, which is beneficial to improving the energy density of the battery cell 10. In addition, the electrode assembly 200 is less likely to shake inside the outer shell 100, which makes the battery cell 10 more stable. Therefore, when 0° < θ1 ≤ 45°, it is not only easy for the electrode assembly 200 to be installed inside the outer shell 100, reducing the possibility of damage to the electrode assembly 200 and the outer shell 100 during installation, but also makes the fit between the outer shell 100 and the electrode assembly 200 better, and the gap between the first connecting wall 113 and the electrode assembly 200 is smaller, which is beneficial to improving the energy density of the battery cell 10. In addition, the electrode assembly 200 is less likely to shake inside the outer shell 100, which makes the battery cell 10 more stable.

[0120] Referring to Figures 2, 8 and 9, Figure 8 is a partially enlarged structural diagram of the battery cell before shaping according to some embodiments of this application, and Figure 9 is a three-dimensional structural diagram of the shaping equipment and battery cell according to some embodiments of this application.

[0121] This application provides a method for preparing a battery cell, comprising:

[0122] S21. Provide a packaging film, and punch a hole in the first part of the packaging film to form a first wall 110. The first wall 110 includes a first sub-wall 111, a second sub-wall 112, and a first connecting wall 113. The second sub-wall 112 protrudes from the first sub-wall 111, and the first connecting wall 113 connects the first sub-wall 111 and the second sub-wall 112. Along the thickness direction of the first part, the distance between the first sub-wall 111 and the second sub-wall 112 is H1, which satisfies 0mm < H1 ≤ 1.5mm.

[0123] S22. Punch a hole in the second part of the packaging film to form a second wall 120.

[0124] S23. Provide an electrode assembly 200, place the electrode assembly 200 on a packaging film, and fold the first part and the second part of the packaging film in half, such that the first wall 110 and the second wall 120 are respectively located on both sides of the electrode assembly 200 along its thickness direction.

[0125] S24. Seal and cut the packaging film to form the outer shell 100. The outer shell 100 and the electrode assembly 200 constitute the battery cell 10.

[0126] S25. During the stage of venting or forming the battery cell 10, the first connecting wall 113 of the battery cell 10 is shaped by the pressure block 320 so that the angle θ1 between the first connecting wall 113 and the thickness direction X of the battery cell satisfies 0°<θ1≤45°.

[0127] In some embodiments, after step S24, a battery cell 10 as shown in FIG7 is formed. The first connecting wall 113 of the battery cell 10 is not formed, the fit between the outer shell 100 and the electrode assembly 200 is poor, and the distance between the first connecting wall 113 and the second electrode group 220 is large along the first direction Y.

[0128] In some embodiments, the shaping device includes a support platform 310 and a pressing block 320. The pressing block 320 is provided with a protrusion 321. The battery cell 10 can be disposed on the support platform 310. The pressing block 320 moves toward the support platform 310, so that the protrusion 321 acts on the first connecting wall 113, thereby causing the first connecting wall 113 to adhere to the electrode assembly 200 along the first direction Y, forming the battery cell 10 as shown in FIG2.

[0129] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other.

[0130] The above are merely preferred embodiments of this application and are not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A battery cell, characterized in that, It includes a housing and an electrode assembly, wherein the electrode assembly is housed in the housing; The outer casing includes a first wall and a second wall disposed opposite to each other along the thickness direction of the battery cell. The first wall includes a first sub-wall, a second sub-wall, and a first connecting wall. Along a direction away from the second wall, the second sub-wall protrudes from the first sub-wall, and the first connecting wall connects the first sub-wall and the second sub-wall. Along the thickness direction of the battery cell, the distance between the first sub-wall and the second sub-wall is H1, which satisfies 0mm<H1≤1.5mm; The angle between the first connecting wall and the thickness direction of the battery cell is θ1, which satisfies 0°<θ1≤45°.

2. The battery cell according to claim 1, characterized in that, 0mm<H1≤1mm, 20°≤θ1≤45°.

3. The battery cell according to claim 1, characterized in that, The electrode assembly includes a first electrode group and a second electrode group, which are stacked together. The dimension of the first electrode group along the first direction is larger than the dimension of the second electrode group along the first direction. The first electrode group is located between the first sub-wall and the second wall, and the second electrode group is located between the first electrode group and the second sub-wall; The first direction is perpendicular to the thickness direction of the battery cell.

4. The battery cell according to claim 3, characterized in that, The first sub-wall has a first end close to the first connecting wall. The second electrode group includes a second positive electrode and a second negative electrode stacked together. Along the first direction, the distance between the end of the second negative electrode close to the first connecting wall and the first end is D, which satisfies D≤1.5mm.

5. The battery cell according to claim 1, characterized in that, Along the thickness direction of the battery cell, the distance between the first sub-wall and the second wall is T1, and the distance between the second sub-wall and the second wall is T2, satisfying T1 < T2.

6. The battery cell according to claim 1, characterized in that, One end of the first connecting wall is connected to the first sub-wall via a first arc transition portion, and the other end of the first connecting wall is connected to the second sub-wall via a second arc transition portion.

7. The battery cell according to claim 1, characterized in that, The first wall further includes a third sub-wall and a second connecting wall. The third sub-wall is located on the side of the second sub-wall away from the first sub-wall. Along the direction away from the second wall, the second sub-wall protrudes from the third sub-wall. The second connecting wall connects the second sub-wall and the third sub-wall. Along the thickness direction of the battery cell, the distance between the second sub-wall and the third sub-wall is H2, which satisfies 0mm < H2 ≤ 1.5mm; The angle between the second connecting wall and the thickness direction of the battery cell is θ2, which satisfies 0°<θ2≤45°.

8. The battery cell according to any one of claims 1-7, characterized in that, An insulating layer is provided between the first wall and the electrode assembly, and the insulating layer at least covers the inner surface of the first connecting wall.

9. An electrical appliance, characterized in that, Includes a battery cell as described in any one of claims 1 to 8, the battery cell being used to provide electrical energy.

10. A method for preparing a battery cell, characterized in that, include: A battery cell is provided, the battery cell including a housing and an electrode assembly, the electrode assembly being housed in the housing; the housing includes a first wall and a second wall disposed opposite to each other along the thickness direction of the battery cell, the first wall including a first sub-wall, a second sub-wall and a first connecting wall, the second sub-wall protruding from the first sub-wall along a direction away from the second wall, the first connecting wall connecting the first sub-wall and the second sub-wall; the distance between the first sub-wall and the second sub-wall along the thickness direction of the battery cell is H1, satisfying 0mm < H1 ≤ 1.5mm; The first connecting wall of the battery cell is shaped by a pressure block so that the angle θ1 between the first connecting wall and the thickness direction of the battery cell satisfies 0°<θ1≤45°.

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