Battery monomer, battery device, electric equipment and manufacturing method of battery monomer

Abstract

The invention relates to a battery monomer, a battery device, electric equipment and a manufacturing method of the battery monomer. The battery monomer comprises a pole piece, and the pole piece comprises a current collector and an active material layer. In the thickness direction of the current collector, the current collector is provided with a first surface and a second surface which are arranged oppositely, and at least one of the first surface and the second surface is provided with an active material layer. Wherein the active material layer comprises a main body part and edge parts, and the edge parts are located on the two opposite sides of the main body part in the width direction of the pole piece. The maximum thickness of the edge part is smaller than the minimum thickness of the main body part, and the surface of the side, away from the current collector, of the edge part is of a plane structure. And by utilizing the relatively flat edge part, the yield and the consistency level of the pole piece can be effectively improved.

Description

Technical Field

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

[0002] In related technologies, solid-state batteries are usually subjected to isostatic pressing treatment. The specific process of isostatic pressing treatment is as follows: the solid-state battery is placed in a closed container filled with a pressurized medium, and a booster system is used to apply a certain pressure to the solid-state battery. In this way, the densification of the solid-state battery can be improved.

[0003] However, the quality rate of the pole pieces in the related art is low. Summary of the invention

[0004] Based on this, it is necessary to provide a battery cell, a battery device, an electrical equipment and a method for manufacturing a battery cell in order to solve the above technical problems, so as to improve the quality rate of the electrode.

[0005] According to a first aspect of the present application, a battery cell is provided, comprising a pole piece, the pole piece comprising a current collector and an active material layer. Along the thickness direction of the current collector, the current collector has a first surface and a second surface disposed opposite to each other, and an active material layer is provided on at least one of the first surface and the second surface. The active material layer comprises a main body portion and an edge portion, and the edge portion is located on opposite sides of the main body portion along the width direction of the pole piece. The maximum thickness of the edge portion is less than the minimum thickness of the main body portion, and the surface of the side of the edge portion away from the current collector is constructed as a planar structure. The pole piece also includes an insulating layer, and along the thickness direction of the current collector, the insulating layer is provided on the side of the edge portion away from the current collector.

[0006] In the technical solution of the present application, since the surface of the side of the edge portion away from the current collector is constructed as a planar structure, the edge portion is relatively flat, and the thickness uniformity of the edge portion is relatively high. In this way, the relatively flat edge portion provides a stable focal length for the subsequent laser processing method or other processing methods (the laser processing method or other processing methods will be used to remove the edge portion later), which is conducive to improving the quality and consistency of the subsequent removal process; in addition, combined with the thickness of the edge portion being less than the thickness of the main part, it can be understood that it is convenient to carry out subsequent gluing or insulation treatment on the relatively flat edge portion, so that the relatively flat edge portion provides a size-stable position for the subsequent gluing or insulation treatment, which is conducive to improving the quality and consistency of the subsequent gluing process; therefore, using the relatively flat edge portion can effectively improve the quality and consistency level of the pole piece. In addition, the insulating layer can be used to electrically isolate the edges of adjacent pole pieces, thereby reducing the risk of positive and negative electrode overlap short circuits in the battery cell, thereby improving the insulation effect and quality of the battery cell.

[0007] In one embodiment, the compaction density of the main body is m1, and the compaction density of the edge portion is m2, wherein m1 and m2 have the same unit, and m1 and m2 satisfy the following condition: 0.9≤m2 / m1≤1.1.

[0008] The compaction density of the main part and the compaction density of the edge part tend to be consistent, reducing the situation where the compaction density at the edge of the pole piece is too low. It can be understood that the compaction density of the edge part of the present application is relatively high, which is conducive to increasing the supporting force of the edge part, thereby reducing the edge shrinkage and deformation of the pole piece of the battery cell during the isostatic pressing process, thereby reducing the risk of positive and negative pole overlap short circuit due to edge shrinkage and deformation of the pole piece of the battery cell.

[0009] In one embodiment, m2 ≥ 3.0 g / cm 3 .

[0010] Compared with the compaction density at the edge of the pole piece in the related art, the compaction density of the edge part of the present application is higher, which is beneficial to increase the supporting force of the edge part, thereby reducing the edge shrinkage and deformation of the pole piece of the battery cell during the isostatic pressing process, thereby reducing the risk of positive and negative pole overlap short circuit due to edge shrinkage and deformation of the pole piece of the battery cell.

[0011] In one of the embodiments, the bonding force of the edge portion is 5N / m-35N / m.

[0012] Controlling the adhesive force of the edge portion within a suitable range is beneficial to improving the bonding strength between the edge portion and the current collector and reducing the probability of "the active material layer detaching from the current collector or the current collector leaking foil".

[0013] In one of the embodiments, the flatness of the edge portion is less than or equal to a preset value, and the preset value is 5 μm-25 μm.

[0014] The relatively flat edge portion provides a stable focal length for subsequent laser processing or other processing methods, which is beneficial to improving the quality and consistency of the subsequent cleaning process; in addition, it is also convenient for subsequent gluing or insulation treatment on the relatively flat edge portion, so that the relatively flat edge portion provides a dimensionally stable position for subsequent gluing or insulation treatment, which is beneficial to improving the quality and consistency of the subsequent gluing process; therefore, using the relatively flat edge portion can effectively improve the quality and consistency level of the pole piece.

[0015] In one embodiment, the edge portion includes two sub-edge portions, which are connected to opposite sides of the main portion along the width direction of the pole piece. The size of the sub-edge portion along the width direction of the pole piece is 0.5 mm-20 mm.

[0016] Setting the size of the sub-edge portion along the width direction of the pole piece within a suitable range, such as setting the size of the sub-edge portion along the width direction of the pole piece to 0.5mm-20mm, is beneficial for meeting the width requirements of the subsequent gluing process while also improving the supporting force of the edge portion.

[0017] In one embodiment, the thickness of the edge portion is 1 μm-100 μm.

[0018] Setting the thickness of the edge portion within a suitable range, such as setting the thickness of the edge portion to 1 μm-100 μm, is conducive to ensuring that the compaction density of the edge portion meets the requirements and can also improve the supporting force of the edge portion.

[0019] In one embodiment, the insulating layer is elastic.

[0020] Since the insulating layer is elastic, the toughness of the pole piece can be improved, which is beneficial to reducing the risk of cracking of the pole piece of the battery cell during the isostatic pressing process.

[0021] In one embodiment, a surface of the insulating layer facing away from the current collector is flush with a surface of the main body facing away from the current collector.

[0022] In this way, a relatively flat pole piece can be formed, thereby improving the force uniformity of the pole piece of the battery cell during the isostatic pressing process, which is beneficial to improving the density of the battery cell.

[0023] According to a second aspect of the present application, a method for manufacturing a battery cell is provided, comprising: providing a current collector; wherein, along the thickness direction of the current collector, the current collector has a first surface and a second surface disposed opposite to each other; forming an active material layer on at least one of the first surface and the second surface; wherein the active material layer comprises a main body portion and an edge portion, and the edge portion is located on opposite sides of the main body portion along the width direction of the current collector. The maximum thickness of the edge portion is less than the minimum thickness of the main body portion, and a surface of the edge portion facing away from the current collector is configured as a planar structure.

[0024] By utilizing the relatively flat edge portion, the quality rate and consistency level of the electrode can be effectively improved.

[0025] An active material layer is formed on at least one of the first surface and the second surface, specifically comprising: forming an initial active material layer on at least one of the first surface and the second surface; wherein the initial active material layer includes an initial edge portion corresponding to the edge portion; and cold pressing at least the initial edge portion of the initial active material layer.

[0026] The present application performs cold pressing on the initial edge portion of the initial active material layer by means of local cold pressing, thereby reducing the situation where the initial edge portion cannot be pressed, forming a relatively flat edge portion, and increasing the compaction density of the edge portion, which is beneficial to improving the quality and consistency of the subsequent cleaning process, and also improving the quality and consistency of the subsequent glue coating process, which is beneficial to improving the quality and consistency level of the electrode.

[0027] In one embodiment, the initial active material layer further includes an initial main body portion corresponding to the main body portion; and at least the initial edge portion of the initial active material layer is cold pressed, specifically including: cold pressing the initial main body portion and cold pressing the initial edge portion.

[0028] In this way, the compaction density and adhesion of the main part and the edge part can be improved, which is beneficial to improving the quality and consistency of the subsequent cleaning process, the quality and consistency of the subsequent glue coating process, and the probability of the active material layer being separated from the current collector can be reduced, which is beneficial to improving the quality and consistency level of the electrode.

[0029] In one of the embodiments, the pressure applied to the initial edge portion is P, where 4905N≤P≤981000N.

[0030] The pressure applied to the initial edge portion satisfies the condition of "4905N≤P≤981000N", which is beneficial for the compaction density of the edge portion to meet the requirements.

[0031] In one embodiment, the cold pressing time for cold pressing the initial edge portion is 0.5s-10s.

[0032] The cold pressing time for the initial edge portion is set within an appropriate range, such as 0.5s-10s, so that the compaction density of the edge portion meets the requirements while also improving the production efficiency of the battery cell.

[0033] In one embodiment, cold pressing is performed on at least an initial edge portion of the initial active material layer, which specifically includes: clamping a clamp at least on the initial edge portion of the initial active material layer to cold press at least the initial edge portion with the help of the clamp.

[0034] At least the initial edge portion is cold pressed by using a clamp, and the clamp and the initial edge portion are in surface-to-surface contact, which can better improve the compaction density and bonding force of the edge portion.

[0035] In one embodiment, the initial active material layer also includes an initial main body portion corresponding to the main body portion; the clamp includes a first clamping portion for clamping the initial main body portion, and a second clamping portion for clamping the initial edge portion; along the thickness direction of the initial active material layer, the second clamping portion is close to a side of the initial active material layer and protrudes beyond a side of the first clamping portion close to the initial active material layer.

[0036] The initial main body portion can be cold pressed using the first clamping portion of the clamp, and the initial edge portion can also be cold pressed using the second clamping portion of the clamp, thereby forming a relatively flat main body portion and edge portion, and the maximum thickness of the edge portion can be made smaller than the minimum thickness of the main body portion, thereby forming a convex pole piece intermediate, which is also beneficial to improving the pole piece quality rate.

[0037] In one embodiment, the flatness of the surface of the fixture close to the initial active material layer is less than 10 μm, so that the installation accuracy of the fixture can be improved, which is conducive to forming a relatively flat main body and edge part, and thus is conducive to improving the quality rate of the pole piece.

[0038] And / or, the roughness of the surface of the clamp close to the initial active material layer is less than 10 μm. In this way, the surface of the clamp close to the initial active material layer can be smoother, which is conducive to forming a relatively flat main body and edge part, and thus is conducive to improving the quality rate of the electrode piece.

[0039] In one of the embodiments, at least the initial edge portion of the initial active material layer is cold pressed, specifically comprising: clamping the initial edge portion with at least one roller group, so as to cold press the initial edge portion with the aid of at least one roller group; wherein the roller group comprises two rollers, and along the thickness direction of the initial edge portion, the two rollers are clamped on opposite sides of the initial edge portion.

[0040] In this way, at least one roller set may be used to cold-press the initial edge portion, thereby increasing the compaction density and bonding strength of the edge portion.

[0041] In one of the embodiments, in the radial direction of the roller, the circular run-out of the roller is less than 2 μm.

[0042] In this way, the installation error of the roller group can be reduced, which is conducive to forming a relatively flat main body and edge part, and is conducive to improving the quality rate of the pole piece.

[0043] In one embodiment, after cold pressing at least an initial edge portion of the initial active material layer, forming the active material layer on at least one of the first surface and the second surface further comprises: performing a thickness reduction process on the initial edge portion to form the active material layer.

[0044] In this way, the surface cleanliness of the edge portion corresponding to the initial edge portion can be improved, thereby improving the quality rate of the electrode piece.

[0045] According to a third aspect of the present application, a battery device is provided, comprising a battery cell according to any of the above embodiments or a battery cell manufactured by the method for manufacturing a battery cell according to any of the above embodiments.

[0046] According to a fourth aspect of the present application, there is provided an electrical device comprising the above-mentioned battery device.

[0047] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present application. Moreover, the same reference numerals are used throughout the drawings to represent the same components. In the drawings:

[0049] Figure 1 A schematic structural diagram of a vehicle according to an embodiment of the present application is shown.

[0050] Figure 2 An exploded schematic diagram of a battery cell according to an embodiment of the present application is shown.

[0051] Figure 3 A schematic structural diagram of a pole piece according to an embodiment of the present application is shown.

[0052] Figure 4 A schematic structural diagram of a pole piece according to another embodiment of the present application is shown.

[0053] Figure 5 A schematic diagram of the first process of a method for manufacturing a pole piece according to an embodiment of the present application is shown.

[0054] Figure 6 A schematic diagram of a second process of a method for manufacturing a pole piece according to an embodiment of the present application is shown.

[0055] Figure 7 A schematic diagram of a second process of a method for manufacturing a pole piece according to another embodiment of the present application is shown.

[0056] Figure 8 A schematic diagram of the third process of the method for manufacturing a pole piece according to an embodiment of the present application is shown.

[0057] Figure numerals: 1, vehicle; 10, battery device; 100, electrode assembly; 110, pole piece; 111, current collector; 1111, first surface; 1112, second surface; 112, active material layer; 1121, main body; 1122, edge portion; 11221, sub-edge portion; 112a, initial active material layer; 112b, initial edge portion; 112c, initial main body; 113, insulating layer; 200, shell; 210, bottom shell; 220, top cover; 300, pole; 20, motor; 30, controller; 40, clamp; 410, first clamping portion; 420, second clamping portion; 421, sub-clamping portion; 50, roller group; 510, roller. DETAILED DESCRIPTION

[0058] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present application, so the present application is not limited by the specific embodiments disclosed below.

[0059] In the description of the present application, it should be understood that if the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. appear, the orientation or position relationship indicated by these terms is based on the orientation or position relationship shown in the accompanying drawings, which is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application.

[0060] In addition, if the terms "first" or "second" appear, these terms are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of this application, if the term "plurality" appears, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0061] In this application, unless otherwise clearly specified and limited, if the terms "installed", "connected", "connected", "fixed" and the like appear, these terms should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integrated connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to the specific circumstances.

[0062] In the present application, unless otherwise clearly specified and limited, if there is a description that a first feature is "above" or "below" a second feature, etc., or similar descriptions appear, it may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature being "above", "above" and "above" the second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. The first feature being "below", "below" and "below" the second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0063] It should be noted that if an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be a central element. If an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. If any, the terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used in this application are for illustrative purposes only and do not represent the only implementation method.

[0064] The edge of the active material layer of the electrode in the related art will present an arc-shaped distribution due to the leveling of the slurry, that is, the thickness of the edge of the active material layer tends to gradually decrease, and the farther away from the center of the active material layer, the smaller the thickness of the edge of the active material layer.

[0065] Normally, laser cleaning is required at the edge of the active material layer in order to carry out the subsequent glue coating process at the edge of the pole piece. However, in the subsequent laser cleaning process, this arc-shaped edge distribution is prone to cause local over-etching of the pole piece (the thinner part at the edge of the active material layer), causing the active material layer to easily separate from the current collector or causing the current collector to leak foil, thereby affecting the quality rate of the pole piece.

[0066] In order to solve the problem of low quality rate of electrode pieces, the present application designs a battery cell, a battery device, an electrical equipment and a method for manufacturing a battery cell, which can make the edge portion of the active material layer of the electrode piece facing away from the surface of the current collector be constructed as a planar structure, so that the relatively flat edge portion provides a stable focal length for subsequent laser processing or other processing methods, and also facilitates subsequent gluing or insulation treatment on the relatively flat edge portion, thereby improving the quality rate of the electrode piece.

[0067] The battery cells and / or battery devices disclosed in the embodiments of the present application may be used, but are not limited to, in electrical equipment such as vehicles, ships or aircraft. Electrical equipment may be, but are not limited to, mobile phones, tablets, laptops, electric toys, electric tools, battery cars, electric cars, ships and spacecraft, etc. Among them, electric toys may include fixed or mobile electric toys, for example, game consoles, electric car toys, electric ship toys and electric airplane toys, etc., and spacecraft may include airplanes, rockets, space shuttles and spacecraft, etc. A power supply system for the electrical equipment may be composed of the battery cells and / or battery devices disclosed in the present application, so that it is convenient to provide electric drive for the electrical equipment and the service life of the electrical equipment can be increased.

[0068] Figure 1 A schematic structural diagram of a vehicle 1 according to an embodiment of the present application is shown. The vehicle 1 may be a fuel vehicle, a gas vehicle or a new energy vehicle. The new energy vehicle may be a pure electric vehicle, a hybrid vehicle or an extended-range vehicle, etc. A battery device 10 is arranged inside the vehicle 1. For example, a battery device 10 may be arranged at the bottom, front or rear of the vehicle 1. The battery device 10 may be used to power the vehicle 1. For example, the battery device 10 may be used as an operating power source for the vehicle 1, for the circuit system of the vehicle 1, such as for the working power requirements during the start-up, navigation and operation of the vehicle 1. In another embodiment of the present application, the battery device 10 may not only be used as an operating power source for the vehicle 1, but also as a driving power source for the vehicle 1, replacing or partially replacing fuel or natural gas to provide driving force for the vehicle 1.

[0069] A motor 20 and a controller 30 may also be provided inside the vehicle 1 . The controller 30 is used to control the battery device 10 to supply power to the motor 20 , for example, to meet the power requirements for starting, navigating, and driving the vehicle 1 .

[0070] Figure 2 An exploded schematic diagram of a battery cell according to an embodiment of the present application is shown.

[0071] See also Figure 2A battery cell according to an embodiment of the present application includes an electrode assembly 100 and a shell 200. The shell 200 includes a bottom shell 210 and a top cover 220 disposed on the bottom shell 210. The bottom shell 210 and the top cover 220 enclose a receiving space for receiving the electrode assembly 100. The electrode assembly 100 can be received in the receiving space, and the shell 200 can be used to well protect the electrode assembly 100.

[0072] The battery cell further includes a pole 300, and the electrode assembly 100 includes a pole piece 110, and a pole ear of the pole piece 110 is electrically connected to the pole 300. The electrode assembly 100 may include a first pole piece and a second pole piece, and at least one of the first pole piece and the second pole piece is the pole piece 110. Specifically, one of the first pole piece and the second pole piece is a positive pole piece, and the other of the first pole piece and the second pole piece is a negative pole piece. The battery cell further includes two poles 300, one of the two poles 300 is electrically connected to the pole ear of the positive pole piece, and the other of the two poles 300 is electrically connected to the pole ear of the negative pole piece.

[0073] Figure 3 and Figure 4 The schematic structural diagrams of the pole piece 110 according to different embodiments of the present application are respectively shown.

[0074] Please refer to Figure 3 and Figure 4 The pole piece 110 of one embodiment of the present application includes a current collector 111 and an active material layer 112. Along the thickness direction of the current collector 111, the current collector 111 has a first surface 1111 and a second surface 1112 that are disposed opposite to each other. The active material layer 112 is disposed on at least one of the first surface 1111 and the second surface 1112.

[0075] The current collector 111 is a component on the electrode sheet 110 for carrying the active material layer 112 and collecting the current generated by the active material layer 112. The current collector 111 may be an aluminum foil or a copper foil.

[0076] The active material layer 112 refers to a material layer disposed on at least one of the first surface 1111 and the second surface 1112 of the current collector 111 . The active material layer 112 may include an active material, a conductive agent, a binder, and the like.

[0077] “At least one of the first surface 1111 and the second surface 1112 is provided with an active material layer 112” may be: at least one of the first surface 1111 and the second surface 1112 is provided with an active material layer 112 (such as Figure 3 As shown); it can also be that: the second surface 1112 is provided with an active material layer 112; it can also be that the first surface 1111 and the second surface 1112 are respectively provided with an active material layer 112 (as shown Figure 4 as shown).

[0078] Among them, the active material layer 112 includes a main body portion 1121 and an edge portion 1122, the edge portion 1122 is located on opposite sides of the main body portion 1121 along the width direction of the pole piece 110, the maximum thickness of the edge portion 1122 is less than the minimum thickness of the main body portion 1121, and the surface of the side of the edge portion 1122 away from the current collector 111 is constructed as a planar structure.

[0079] The main body portion 1121 refers to a portion of the active material layer 112 that is located inside the edge portion 1122 and occupies a larger proportion of the active material layer 112 .

[0080] The edge portion 1122 refers to a portion of the active material layer 112 that is located outside the main body portion 1121 and occupies a smaller proportion of the active material layer 112 .

[0081] The width direction W of the pole piece 110, the length direction L of the pole piece 110, and the thickness direction Z of the pole piece 110 are perpendicular to each other. Among them, the thickness direction Z of the pole piece 110 is parallel to the thickness direction of the current collector 111, and the length direction L of the pole piece 110 refers to the conveying direction of the strip corresponding to the pole piece 110. It can be understood that during the production process, the pole piece 110 is continuously conveyed and processed along the length direction L of the pole piece 110, and the width direction W represents the lateral dimension direction of the pole piece 110. The length dimension of the pole piece 110 and the width dimension of the pole piece 110 can be equal or unequal, and the size between the two can be determined according to the slitting process, and no specific limitation is made here.

[0082] The strip corresponding to the pole piece 110 will be cut at a certain interval along the length direction L of the pole piece 110. Therefore, the edge portion 1122 is connected to the opposite sides of the main portion 1121 along the width direction of the pole piece 110, which can meet the application requirements of the scenario of "the strip corresponding to the pole piece 110 is cut at a certain interval along the length direction L of the pole piece 110".

[0083] Since the surface of the side of the edge portion 1122 facing away from the collector 111 is constructed as a planar structure, the edge portion 1122 is relatively flat, and the thickness uniformity of the edge portion 1122 is high. In this way, the position of the edge portion 1122 that needs to be cleared is constructed as a planar structure, so that the relatively flat edge portion 1122 provides a stable focal length for subsequent laser processing or other processing methods (laser processing or other processing methods will be used to clear the edge portion 1122 later), which is beneficial to improving the quality and consistency of the subsequent cleaning process; in addition, combined with the fact that the thickness of the edge portion 1122 is less than the thickness of the main portion 1121, it can be understood that it is convenient to perform subsequent gluing or insulation treatment on the relatively flat edge portion 1122, so that the relatively flat edge portion 1122 provides a size-stable position for subsequent gluing or insulation treatment, which is beneficial to improving the quality and consistency of the subsequent gluing process; therefore, using the relatively flat edge portion 1122 can effectively improve the quality and consistency level of the pole piece 110.

[0084] In some embodiments, the flatness of the edge portion 1122 is less than or equal to a preset value, and the preset value is 5 μm-25 μm.

[0085] Illustratively, the preset value is 5 μm, 10 μm, 15 μm, 20 μm or 25 μm.

[0086] The relatively flat edge portion 1122 provides a stable focal length for subsequent laser processing or other processing methods, which is beneficial to improving the quality and consistency of the subsequent cleaning process; it is also convenient for subsequent gluing or insulation treatment on the relatively flat edge portion 1122, so that the relatively flat edge portion 1122 provides a dimensionally stable position for subsequent gluing or insulation treatment, which is beneficial to improving the quality and consistency of the subsequent gluing process; therefore, using the relatively flat edge portion 1122 can effectively improve the quality and consistency level of the pole piece 110.

[0087] In some embodiments, the compaction density of the main body portion 1121 is m1, and the compaction density of the edge portion 1122 is m2, wherein m1 and m2 have the same unit, and m1 and m2 satisfy the following condition: 0.9≤m2 / m1≤1.1.

[0088] Illustratively, m2 / m1 may be 0.9, 1.0 or 1.1.

[0089] Since m1 and m2 satisfy the following condition: 0.9≤m2 / m1≤1.1, the compaction density of the main part 1121 and the compaction density of the edge part 1122 tend to be consistent, reducing the situation where the compaction density at the edge of the pole piece 110 is too low. It can be understood that the compaction density of the edge part 1122 of the present application is relatively high, which is beneficial to increase the supporting force of the edge part 1122, thereby reducing the edge shrinkage and deformation of the pole piece 110 of the battery cell during the isostatic pressing process, thereby reducing the risk of positive and negative electrode overlap short circuit due to edge shrinkage and deformation of the pole piece 110 of the battery cell.

[0090] In some embodiments, m2 ≥ 3.0 g / cm 3 .

[0091] m2 can be 3.0g / cm 3 、3.1g / cm 3 、3.2g / cm 3 、3.3g / cm 3 、3.4g / cm 3 or 3.5g / cm 3 wait.

[0092] Thus, compared with the compaction density at the edge of the pole piece in the related art, the compaction density of the edge portion 1122 of the present application is higher, which is beneficial to increase the supporting force of the edge portion 1122, thereby reducing the edge shrinkage and deformation of the pole piece 110 of the battery cell during the isostatic pressing process, thereby reducing the risk of positive and negative pole overlap short circuit due to edge shrinkage and deformation of the pole piece 110 of the battery cell.

[0093] In some embodiments, the adhesive force of edge portion 1122 is 5 N / m-35 N / m.

[0094] Illustratively, the adhesive force of the edge portion 1122 is 5 N / m, 10 N / m, 15 N / m, 20 N / m, 25 N / m, 30 N / m, or 35 N / m.

[0095] Controlling the adhesive force of the edge portion 1122 within a suitable range is beneficial to improving the bonding strength between the edge portion 1122 and the current collector 111 and reducing the probability of "the active material layer 112 being separated from the current collector 111 or the current collector 111 leaking foil material".

[0096] In some embodiments, the edge portion 1122 is connected to two opposite sides of the main portion 1121 along the width direction of the pole piece 110 , wherein the width direction of the pole piece 110 is perpendicular to the thickness direction of the current collector 111 .

[0097] In some embodiments, the edge portion 1122 includes two sub-edge portions 11221, which are connected to opposite sides of the main portion 1121 along the width direction of the pole piece 110, and the size of the sub-edge portion 11221 along the width direction of the pole piece 110 is 0.5mm-20mm.

[0098] Illustratively, a dimension of the sub-edge portion 11221 along the width direction of the pole piece 110 is 0.5 mm, 1 mm, 2 mm, 4 mm, 6 mm, 8 mm, 10 mm, 12 mm, 14 mm, 16 mm, 18 mm or 20 mm.

[0099] The dimension of the sub-edge portion 11221 along the width direction of the pole piece 110 is set within a suitable range. For example, the dimension of the sub-edge portion 11221 along the width direction of the pole piece 110 is set to 0.5mm-20mm. This is beneficial for meeting the width requirement of the subsequent glue coating process while also improving the supporting force of the edge portion 1122.

[0100] In some embodiments, the thickness of edge portion 1122 is 1 μm-100 μm.

[0101] Illustratively, the thickness of edge portion 1122 is 1 μm, 10 μm, 20 μm, 30 μm, 40 μm, 50 μm, 60 μm, 70 μm, 80 μm, 90 μm, or 100 μm.

[0102] Setting the thickness of the edge portion 1122 within a suitable range, such as setting the thickness of the edge portion 1122 to 1 μm-100 μm, is beneficial for ensuring that the compaction density of the edge portion 1122 meets the requirements and can also improve the supporting force of the edge portion 1122 .

[0103] In some embodiments, the pole piece 110 further includes an insulating layer 113 . Along the thickness direction of the current collector 111 , the insulating layer 113 is disposed on a side of the edge portion 1122 facing away from the current collector 111 .

[0104] In this way, the insulating layer 113 can be used to electrically isolate the edges of adjacent pole pieces 110, thereby reducing the risk of positive and negative pole overlap short circuits in the battery cell, thereby improving the insulation effect and quality of the battery cell.

[0105] In some embodiments, the insulating layer 113 is elastic.

[0106] For example, the insulating layer 113 may be insulating glue.

[0107] Since the insulating layer 113 is elastic, the toughness of the pole piece 110 can be improved, which is beneficial to reduce the risk of cracking of the pole piece 110 of the battery cell during the isostatic pressing process.

[0108] In some embodiments, a surface of the insulating layer 113 facing away from the current collector 111 is flush with a surface of the main body 1121 facing away from the current collector 111 .

[0109] In this way, a relatively flat pole piece 110 can be formed, thereby improving the force uniformity of the pole piece 110 of the battery cell during the isostatic pressing process, thereby facilitating improving the compactness of the battery cell.

[0110] In some embodiments, the battery cells may be solid-state battery cells.

[0111] An embodiment of the present application provides a method for manufacturing a battery cell, comprising:

[0112] S10 , providing a current collector 111 ; wherein, along a thickness direction of the current collector 111 , the current collector 111 has a first surface 1111 and a second surface 1112 that are disposed opposite to each other.

[0113] S20, forming an active material layer 112 (eg, Figure 5 as shown).

[0114] The active material layer 112 includes a main body portion 1121 and an edge portion 1122, and the edge portion 1122 is located on opposite sides of the main body portion 1121 along the width direction of the current collector 111. The maximum thickness of the edge portion 1122 is less than the minimum thickness of the main body portion 1121, and the surface of the edge portion 1122 facing away from the current collector 111 is configured as a planar structure. The width direction of the current collector 111 is parallel to the width direction of the pole piece 110.

[0115] By utilizing the relatively flat edge portion 1122 , the quality and consistency level of the pole piece 110 can be effectively improved.

[0116] In some embodiments, step S20 of forming the active material layer 112 on at least one of the first surface 1111 and the second surface 1112 specifically includes:

[0117] S21, forming an initial active material layer 112a on at least one of the first surface 1111 and the second surface 1112; wherein the initial active material layer 112a includes an initial edge portion 112b corresponding to the edge portion 1122;

[0118] S22 . Cold-press at least the initial edge portion 112 b of the initial active material layer 112 a .

[0119] Compared to the overall cold pressing of the initial active material layer 112a (during the overall cold pressing of the initial active material layer 112a, there is a situation where the initial edge portion 112b cannot be pressed), the present application performs cold pressing on the initial edge portion 112b of the initial active material layer 112a by local cold pressing, thereby reducing the situation where the initial edge portion 112b cannot be pressed, forming a relatively flat edge portion 1122, and also improving the compaction density of the edge portion 1122, which is beneficial to improving the quality and consistency of the subsequent cleaning process, and also improving the quality and consistency of the subsequent glue coating process, which is beneficial to improving the quality and consistency level of the electrode 110.

[0120] In addition, compared with the hot pressing process (since the hot pressing process is prone to severe adhesion due to the stickiness of the pole piece during the hot pressing process, the hot pressing process is more suitable for the electrode assembly level), the present application adopts a cold pressing process to reduce the severe adhesion of the pole piece 110 to the clamp 40 or the roller 510, which is conducive to the better application of the battery cell manufacturing method of the present application to the pole piece level, and compared with the application to the electrode assembly 100 level (if under the same pressure, the pressure acting on the electrode assembly 100 is difficult to act on the initial edge portion 112b; in the case of application to the electrode assembly 100 level , if the same compaction density is achieved, a greater pressure may be required to act on the initial active material layer 112a, resulting in the initial active material layer 112a being crushed). The battery cell manufacturing method of the present application can be applied to the electrode layer. If the same compaction density is achieved, a smaller pressure can be applied to the initial active material layer 112a to reduce the possibility of crushing the initial active material layer 112a. Local cold pressing is performed on the initial edge portion 112b, which is beneficial to better improve the compaction density and adhesion of the edge portion 1122, and is also beneficial to improving the quality rate of the electrode 110.

[0121] In addition, by cold pressing the initial edge portion 112 b , the active material and the binder of the initial edge portion 112 b can be mixed evenly, which is beneficial to improve the bonding force of the edge portion 1122 .

[0122] In some embodiments, the initial active material layer 112a further includes an initial main body portion 112c corresponding to the main body portion 1121. The step S22 of cold pressing at least the initial edge portion 112b of the initial active material layer 112a specifically includes:

[0123] S221. Cold-press the initial main body portion 112c, and cold-press the initial edge portion 112b.

[0124] The initial main body portion 112c may be cold pressed first, and then the initial edge portion 112b; the initial edge portion 112b may be cold pressed first, and then the initial main body portion 112c; the initial edge portion 112b may be cold pressed at the same time as the initial main body portion 112c; no specific limitation is made here.

[0125] It is understandable that, since the initial main body portion 112c accounts for a large proportion, the initial main body portion 112c accounts for almost more than 90% of the initial active material layer 112a. Therefore, cold pressing the initial main body portion 112c is equivalent to cold pressing the initial active material layer 112a as a whole.

[0126] The whole part 1121 and the part 1122 may be cold pressed first and then partially cold pressed, or the part 1121 and then the whole part may be cold pressed first. In this way, the compaction density and the adhesion force of the main part 1121 and the edge part 1122 may be increased, which may help to improve the quality and consistency of the subsequent cleaning process, and the quality and consistency of the subsequent glue coating process. It may also reduce the probability of the active material layer 112 being separated from the current collector 111, which may help to improve the quality and consistency level of the electrode 110.

[0127] In some embodiments, the pressure applied to the initial edge portion 112b is P, where 4905N≤P≤981000N.

[0128] For example, P may be 4905N, 9810N, 98100N or 981000N.

[0129] It can be connected to the following clamp 40 or roller group 50 through a hydraulic cylinder to apply corresponding pressure to the initial edge portion 112b. The pressure of the pressure oil to be supplied to the hydraulic cylinder can be set according to the pressure applied to the initial edge portion 112b, so that the pressure applied to the initial edge portion 112b satisfies the condition of "4905N≤P≤981000N", which is beneficial for the compaction density of the edge portion 1122 to meet the requirements.

[0130] In some embodiments, the cold pressing time for cold pressing the initial edge portion 112b is 0.5s-10s.

[0131] Illustratively, the cold pressing time for cold pressing the initial edge portion 112b is 0.5s, 1s, 2s, 3s, 4s, 5s, 6s, 7s, 8s, 9s or 10s.

[0132] The cold pressing time for the initial edge portion 112b is set within a suitable range, such as 0.5s-10s, so that the compaction density of the edge portion 1122 meets the requirements and the manufacturing efficiency of the battery cell can be improved.

[0133] In some embodiments, the step S22 of cold pressing at least the initial edge portion 112b of the initial active material layer 112a specifically includes:

[0134] S222, clamping the clamp 40 at least on the initial edge portion 112b of the initial active material layer 112a, so as to cold-press at least the initial edge portion 112b by means of the clamp 40 (eg, Figure 6 as shown).

[0135] The clamp 40 can be clamped at least at the initial edge portion 112b of the initial active material layer 112a so that at least the initial edge portion 112b can be cold pressed with the aid of the clamp 40; the clamp 40 can also be clamped at the initial edge portion 112b and the initial main body portion 112c respectively so that the initial active material layer 112a can be cold pressed with the aid of the clamp 40; no specific limitation is made here.

[0136] It should be noted that, in this embodiment, the initial edge portion 112 b may be partially cold pressed by using the clamp 40 , and then the initial active material layer 112 a may be entirely cold pressed by using a pressing roller.

[0137] At least the initial edge portion 112 b is cold-pressed by using the clamp 40 , and the clamp 40 and the initial edge portion 112 b are in surface-to-surface contact, which can better improve the compaction density and bonding force of the edge portion 112 .

[0138] In some embodiments, the clamp 40 includes a first clamping portion 410 for clamping the initial main body portion 112c, and a second clamping portion 420 for clamping the initial edge portion 112b. Along the thickness direction of the initial active material layer 112a, the second clamping portion 420 is close to the side of the initial active material layer 112a and protrudes beyond the side of the first clamping portion 410 close to the initial active material layer 112a.

[0139] The initial main portion 112 c refers to a portion of the initial active material layer 112 a having a smaller thickness variation and a smaller flatness, and the initial edge portion 112 b refers to a portion of the initial active material layer 112 a having a gradually varying thickness.

[0140] The first clamping portion 410 refers to a portion of the clamp 40 for clamping the initial main body portion 112c. The second clamping portion 420 refers to a portion of the clamp 40 for clamping the initial edge portion 112b.

[0141] The initial edge portion 112b includes two sub-initial edge portions (not shown in the figure) corresponding one to one with the two sub-edge portions 11221, and the second clamping portion 420 includes four sub-clamping portions 421, two of which are used to clamp one of the sub-initial edge portions, and the other two sub-clamping portions 421 are used to clamp the other sub-initial edge portion.

[0142] Since the second clamping portion 420 is close to the side of the initial active material layer 112a and protrudes beyond the side of the first clamping portion 410 close to the initial active material layer 112a, in the process of clamping the initial active material layer 112a with a certain pressure using the clamp 40, the initial main body portion 112c can be cold pressed using the first clamping portion 410 of the clamp 40, and the initial edge portion 112b can be cold pressed using the second clamping portion 420 of the clamp 40, thereby forming a relatively flat main body portion 1121 and edge portion 1122, and the maximum thickness of the edge portion 1122 can be made smaller than the minimum thickness of the main body portion 1121, thereby forming a convex pole piece intermediate, which is also beneficial to improving the quality rate of the pole piece 110.

[0143] In some embodiments, the flatness of the surface of one side of the jig 40 close to the initial active material layer 112 a is less than 10 μm.

[0144] Illustratively, the flatness of the surface of one side of the jig 40 close to the initial active material layer 112 a is 1 μm or 5 μm.

[0145] In this way, the installation accuracy of the fixture 40 can be improved, which is conducive to forming a relatively flat main body portion 1121 and edge portion 1122 , and is conducive to improving the quality rate of the pole piece 110 .

[0146] In some embodiments, the roughness of the surface of the jig 40 on one side close to the initial active material layer 112 a is less than 10 μm.

[0147] For example, the roughness of the surface of the jig 40 on one side close to the initial active material layer 112 a is 1 μm or 5 μm.

[0148] In this way, the surface of the clamp 40 on one side close to the initial active material layer 112 a can be made smoother, which is beneficial for forming a relatively flat main body portion 1121 and edge portion 1122 , and is beneficial for improving the quality rate of the electrode piece 110 .

[0149] In some embodiments, the step S22 of cold pressing at least the initial edge portion 112b of the initial active material layer 112a specifically includes:

[0150] S223, clamping the initial edge portion 112b with at least one roller group 50, so as to cold press the initial edge portion 112b with the help of at least one roller group 50 (such as Figure 7 as shown).

[0151] The roller set 50 includes two rollers 510 , and along the thickness direction of the initial edge portion 112 b , the two rollers 510 are clamped at opposite sides of the initial edge portion 112 b .

[0152] It may be that, along the thickness direction of the initial edge portion 112 b , one roller set 50 is clamped at two opposite sides of one sub-edge portion 11221 , and another roller set 50 is clamped at two opposite sides of another sub-edge portion 11221 .

[0153] In this embodiment, before or after step S223, two pressing rollers (not shown in the figure) may be used to cold press the initial main body portion 112c.

[0154] In this way, at least one roller set 50 may be used to cold-press the initial edge portion 112 b to increase the compaction density and adhesive force of the edge portion 112 .

[0155] It should be noted that, according to the design requirements of the compaction density and adhesion force of the edge portion 1122, the clamp 40 or at least one roller group 50 can be selected to cold-press at least the initial edge portion 112b. For example, if there is a design requirement for high pressure density, the clamp 40 can be selected to cold-press at least the initial edge portion 112b; if there is a design requirement for low pressure density, at least one roller group 50 can be selected to cold-press the initial edge portion 112b.

[0156] In some embodiments, in the radial direction of the roller 510 , the circular run-out of the roller 510 is less than 2 μm.

[0157] In this way, the installation error of the roller set 50 can be reduced, which is conducive to forming a relatively flat main body portion 1121 and edge portion 1122 , and is conducive to improving the quality rate of the pole piece 110 .

[0158] In some embodiments, after step S22 of cold pressing at least the initial edge portion 112b of the initial active material layer 112a, step S20 of forming the active material layer 112 on at least one of the first surface 1111 and the second surface 1112 further includes:

[0159] S23, the initial edge portion 112b is subjected to a thickness reduction process to form an active material layer 112 (which can be combined with Figure 6 and Figure 8 to understand).

[0160] In this way, the surface cleanliness of the edge portion 1122 corresponding to the initial edge portion 112 b can be improved, thereby improving the quality of the pole piece 110 .

[0161] In some embodiments, the method for manufacturing a battery cell further includes:

[0162] A plurality of first pole sheets and a plurality of second pole sheets are alternately stacked and pressed together, wherein at least one of the first pole sheets and the second pole sheets is the pole sheet 110 .

[0163] The plurality of first pole pieces and the plurality of second pole pieces after the pressing process are subjected to a glue injection process to obtain an initial electrode assembly.

[0164] The initial electrode assembly is subjected to isostatic pressing to obtain the electrode assembly 100 .

[0165] The electrode assembly 100 is assembled into the case 200 to obtain a battery cell.

[0166] In some embodiments, the flatness of the edge portion 1122 is less than or equal to a preset value, the preset value is 5 μm-25 μm, and m1 and m2 satisfy the following condition: 0.9≤m2 / m1≤1.1.

[0167] Compared with the pole piece in the related art (the flatness at the edge of the pole piece in the related art is 30μm-100μm, and the compaction density at the edge of the pole piece in the related art is 2.0g / cm 3 , the bonding force at the edge of the pole piece in the related art is 0.5N / m), the flatness of the edge portion 1122 of the present application is 5μm-25μm, which is conducive to significantly improving the subsequent laser cleaning and insulation glue coating quality rate. Specifically, the subsequent laser cleaning and insulation glue coating quality rate is improved by about 20%-30%; by measuring the weight and thickness of the edge portion 1122 of the pole piece 110, it is known that the compaction density of the edge portion 1122 of the pole piece 110 is increased to 3.5g / cm 3 Through the adhesion test, it is known that the adhesion of the edge portion 1122 of the pole piece 110 is increased to 35N / m. Therefore, by using the battery cell and the battery cell manufacturing method of the present application, the compaction density and adhesion of the edge portion 1122 can be improved, and the quality rate of the pole piece 110 can also be improved.

[0168] An embodiment of the present application provides a battery device 10, including a battery cell according to any of the above embodiments or a battery cell manufactured by the manufacturing method of the battery cell according to any of the above embodiments.

[0169] The battery device 10 may include one battery cell, or may include multiple battery cells, and the multiple battery cells are connected in series, in parallel, or in a mixed connection, wherein the mixed connection is a combination of series and parallel connection.

[0170] An embodiment of the present application provides an electrical device, including the battery device 10 described above.

[0171] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0172] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be construed as limiting the scope of the patent application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent application shall be subject to the attached claims.

Claims

1. A battery cell, characterized in that: It comprises a pole piece (110), wherein the pole piece (110) comprises: A current collector (111), wherein along a thickness direction of the current collector (111), the current collector (111) has a first surface (1111) and a second surface (1112) disposed opposite to each other; and an active material layer (112), wherein the active material layer (112) is provided on at least one of the first surface (1111) and the second surface (1112); The active material layer (112) comprises a main body portion (1121) and an edge portion (1122). The edge portion (1122) is located on two opposite sides of the main body portion (1121) along the width direction of the pole piece (110); The maximum thickness of the edge portion (1122) is less than the minimum thickness of the main body portion (1121), and a surface of a side of the edge portion (1122) facing away from the current collector (111) is constructed as a planar structure; The pole piece (110) further includes an insulating layer (113); Along the thickness direction of the current collector (111), the insulating layer (113) is arranged on a side of the edge portion (1122) away from the current collector (111).

2. The battery cell according to claim 1, characterized in that: The compaction density of the main body portion (1121) is m1, and the compaction density of the edge portion (1122) is m2; Among them, m1 and m2 have the same unit, and m1 and m2 satisfy the following condition: 0.9≤m2 / m1≤1.

1.

3. The battery cell according to claim 2, characterized in that: m2≥3.0g / cm 3 。 4. The battery cell according to claim 1, characterized in that: The bonding force of the edge portion (1122) is 5N / m-35N / m.

5. The battery cell according to claim 1, characterized in that: The flatness of the edge portion (1122) is less than or equal to a preset value; the preset value is 5 μm-25 μm.

6. The battery cell according to claim 5, characterized in that: The edge portion (1122) includes two sub-edge portions (11221); The two sub-edge portions (11221) are connected to opposite sides of the main body portion (1121) along the width direction of the pole piece (110); The dimension of the sub-edge portion (11221) along the width direction of the pole piece (110) is 0.5 mm-20 mm.

7. The battery cell according to any one of claims 1 to 6, characterized in that: The thickness of the edge portion (1122) is 1 μm-100 μm.

8. The battery cell according to any one of claims 1 to 6, characterized in that: The insulating layer (113) has elasticity.

9. The battery cell according to any one of claims 1 to 6, characterized in that: A surface of one side of the insulating layer (113) facing away from the current collector (111) is arranged flush with a side of the main body portion (1121) facing away from the current collector (111).

10. A method for manufacturing a battery cell, characterized in that: include: Providing a current collector (111); wherein, along a thickness direction of the current collector (111), the current collector (111) has a first surface (1111) and a second surface (1112) disposed opposite to each other; forming an active material layer (112) on at least one of the first surface (1111) and the second surface (1112); The active material layer (112) comprises a main body portion (1121) and an edge portion (1122), and the edge portion (1122) is located on two opposite sides of the main body portion (1121) along the width direction of the current collector (111); The maximum thickness of the edge portion (1122) is less than the minimum thickness of the main body portion (1121), and a surface of a side of the edge portion (1122) facing away from the current collector (111) is constructed as a planar structure; The step of forming an active material layer (112) on at least one of the first surface (1111) and the second surface (1112) specifically comprises: forming an initial active material layer (112a) on at least one of the first surface (1111) and the second surface (1112); wherein the initial active material layer (112a) includes an initial edge portion (112b) corresponding to the edge portion (1122); At least the initial edge portion (112b) of the initial active material layer (112a) is cold pressed.

11. The method for manufacturing a battery cell according to claim 10, characterized in that: The initial active material layer (112a) further comprises an initial main body portion (112c) corresponding to the main body portion (1121); and cold pressing at least the initial edge portion (112b) of the initial active material layer (112a) specifically comprises: The initial body portion (112c) is cold pressed, and the initial edge portion (112b) is cold pressed.

12. The method for manufacturing a battery cell according to claim 10, characterized in that: The pressure applied to the initial edge portion (112b) is P; Among them, 4905N≤P≤981000N.

13. The method for manufacturing a battery cell according to claim 12, characterized in that: The cold pressing time for cold pressing the initial edge portion (112b) is 0.5s-10s.

14. The method for manufacturing a battery cell according to claim 10, characterized in that: The step of cold pressing at least the initial edge portion (112b) of the initial active material layer (112a) specifically comprises: A clamp (40) is clamped at least on the initial edge portion (112b) of the initial active material layer (112a) to cold-press at least the initial edge portion (112b) by means of the clamp (40).

15. The method for manufacturing a battery cell according to claim 14, characterized in that: The initial active material layer (112a) further includes an initial main body portion (112c) corresponding to the main body portion (1121); The clamp (40) comprises a first clamping portion (410) for clamping the initial main body portion (112c), and a second clamping portion (420) for clamping the initial edge portion (112b); Along the thickness direction of the initial active material layer (112a), a side of the second clamping portion (420) close to the initial active material layer (112a) protrudes beyond a side of the first clamping portion (410) close to the initial active material layer (112a).

16. The method for manufacturing a battery cell according to claim 14, characterized in that: The flatness of a surface of one side of the clamp (40) close to the initial active material layer (112a) is less than 10 μm; and / or The roughness of a surface of one side of the clamp (40) close to the initial active material layer (112a) is less than 10 μm.

17. The method for manufacturing a battery cell according to claim 10, characterized in that: The step of cold pressing at least the initial edge portion (112b) of the initial active material layer (112a) specifically comprises: Using at least one roller group (50) to clamp the initial edge portion (112b), so as to cold-press the initial edge portion (112b) with the aid of the at least one roller group (50); The roller set (50) comprises two rollers (510), and along the thickness direction of the initial edge portion (112b), the two rollers (510) are clamped on opposite sides of the initial edge portion (112b).

18. The method for manufacturing a battery cell according to claim 17, characterized in that: In the radial direction of the roller (510), the circular runout of the roller (510) is less than 2 μm.

19. The method for manufacturing a battery cell according to claim 10, characterized in that: After cold pressing at least the initial edge portion (112b) of the initial active material layer (112a), forming the active material layer (112) on at least one of the first surface (1111) and the second surface (1112) further comprises: The initial edge portion (112b) is subjected to a thickness reduction process to form the active material layer (112).

20. A battery device, characterized in that: A battery cell comprising a battery cell as claimed in any one of claims 1 to 9 or a battery cell prepared by the method for preparing a battery cell as claimed in any one of claims 10 to 19.

21. An electrical equipment, characterized in that: Comprising a battery device as claimed in claim 20.

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