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

Abstract

The present application relates to a battery cell, a battery device, an electrical device and a method for manufacturing a battery cell. The method for manufacturing a battery cell includes: 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; the first surface and the second surface both have a main body region and two edge regions; a preset layer is formed in the edge region of at least one of the first surface and the second surface; wherein the surface of the first surface and the second surface provided with the preset layer is a target surface; an initial active material layer covering the preset layer is formed on the target surface; wherein the initial active material layer includes an initial main body portion disposed in the main body region, and an initial edge portion covered by the preset layer. The preset layer located in the edge region can be used to protect the portion of the current collector located in the edge region, thereby effectively improving the superiority rate of the electrode sheet.

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 method for manufacturing a battery cell is provided, comprising: providing a current collector; wherein, along a thickness direction of the current collector, the current collector has a first surface and a second surface arranged opposite to each other; the first surface and the second surface both have a main body region and two edge regions, and the two edge regions are respectively located on opposite sides of the main body region along a width direction of the current collector; a preset layer is formed in the edge region of at least one of the first surface and the second surface; wherein the surface of the first surface and the second surface provided with the preset layer is a target surface; an initial active material layer covering the preset layer is formed on the target surface; wherein the initial active material layer includes an initial main body portion provided in the main body region, and an initial edge portion covering the preset layer; wherein the thickness of the preset layer is less than the thickness of the initial main body portion.

[0006] In the technical solution of the present application, a preset layer is arranged on the edge area of ​​at least one of the first surface and the second surface. The preset layer located in the edge area can be used to protect the portion of the current collector located in the edge area, thereby reducing the probability of foil leakage in the edge area of ​​the current collector due to the subsequent process of clearing the initial edge portion, thereby effectively improving the quality rate of the electrode.

[0007] In one of the embodiments, the flatness of the preset layer is less than or equal to a first preset value, wherein the first preset value is 2 μm-5 μm.

[0008] The preset layer is relatively flat, and because the thickness of the preset layer located in the edge area and pre-set is smaller than the thickness of the initial main part of the initial active material layer, this is conducive to reducing the sum of the thicknesses of the portion of the initial active material layer located in the edge area (i.e., the initial edge portion) and the preset layer, and the thickness difference between the portion of the initial active material layer located in the main area (i.e., the initial main portion), which is conducive to improving the thickness uniformity of the intermediate of the electrode piece, which is conducive to uniformly compacting the intermediate of the electrode piece, which is conducive to improving the compaction density and quality of the electrode piece; it can also make the relatively flat initial edge portion provide a stable focal length for subsequent laser processing or other processing methods (laser processing or other processing methods will be used to clear the initial edge portion subsequently), which is conducive to improving the quality and consistency of the subsequent clearing process; and the relatively flat preset layer can also provide a dimensionally stable position for subsequent gluing or insulation processing, which is conducive to improving the quality and consistency of the subsequent gluing process.

[0009] In one of the embodiments, after forming an initial active material layer covering a preset layer on the target surface, the method for manufacturing a battery cell further includes: performing a cold pressing process on the initial active material layer.

[0010] By cold pressing the initial active material layer, the serious bonding of the pole piece can be reduced, and the compaction density, bonding strength and quality rate of the pole piece can be improved.

[0011] In one embodiment, after the initial active material layer is cold pressed, the compaction density of the initial main body portion is m1, and the compaction density of the initial 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.

[0012] Since m1 and m2 satisfy the following conditions: 0.9≤m2 / m1≤1.1, the compaction density of the initial main part and the compaction density of the initial 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 initial active material layer of the present application is relatively high and the distribution is relatively even, which is beneficial to increase the supporting force of the pole piece, 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 electrode overlap short circuit due to edge shrinkage and deformation of the pole piece of the battery cell.

[0013] In one embodiment, m2 ≥ 3.0 g / cm 3 .

[0014] The compaction density of the initial active material layer of the present application is relatively high at all locations, which is beneficial to increase the supporting force of the pole piece, 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.

[0015] In one embodiment, after the initial active material layer is subjected to cold pressing, the bonding force of the initial edge portion is 5N / m-50N / m.

[0016] Controlling the bonding force of the initial edge portion within an appropriate range is beneficial to improving the bonding strength between the initial edge portion and the current collector, and can also improve the bonding strength between the initial active material layer and the current collector, thereby reducing the probability of "the initial active material layer detaching from the current collector or the current collector leaking foil".

[0017] In one embodiment, after the initial active material layer is subjected to cold pressing, the method for manufacturing a battery cell further includes: removing at least a portion of the initial edge portion to obtain the active material layer.

[0018] After at least part of the initial edge portion is removed, it is convenient to carry out subsequent gluing processes, etc. in the area where the initial edge portion was originally located.

[0019] In one embodiment, after removing at least part of the initial edge portion, the method for manufacturing the battery cell further includes: forming a thickening layer on the side of the preset layer away from the current collector. The sum of the thickness of the thickening layer and the preset layer is H1, and the thickness of the active material layer is H2, wherein H1 and H2 have the same unit, and H1 and H2 satisfy the following condition: 0.95≤H1 / H2≤1.05.

[0020] It can be understood that H1 / H2 tends to be equal to 1, that is, the sum of the thickness of the thickened layer and the preset layer tends to be equal to the thickness of the active material layer. Therefore, the thickened layer can be used to form a relatively flat electrode sheet, which can improve the uniformity of the force on the electrode sheet of the battery cell during the isostatic pressing process, which is beneficial to improve the density of the battery cell.

[0021] In one of the embodiments, H1 / H2=1; and / or, a surface of the thickened layer facing away from the preset layer is flush with a surface of the active material layer facing away from the current collector.

[0022] In this way, a relatively flat pole piece can be obtained, 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] In one embodiment, the material of the thickening layer includes an insulating material. Thus, the thickening layer can be used to electrically isolate the edges of adjacent pole pieces, thereby reducing the risk of positive and negative poles overlapping and short-circuiting the battery cell, thereby improving the insulation effect and quality of the battery cell.

[0024] And / or, the hardness of the preset layer is greater than the hardness of the thickened layer. On the one hand, the hardness of the preset layer is greater, which reduces the probability of deformation of the preset layer during the cold pressing process, thereby reducing the situation where the compaction density of the active material layer is affected by the cold pressing deformation of the preset layer, which is beneficial to improve the compaction density and adhesion of the active material layer. On the other hand, the hardness of the thickened layer is smaller, that is, the flexibility of the thickened layer is higher, which is beneficial to reduce the probability of cracking of the pole piece during the isostatic pressing process, thereby improving the superiority and reliability of the battery cell.

[0025] In one embodiment, the thickened layer is elastic.

[0026] Since the thickened layer is elastic, the probability of cracking of the pole piece during isostatic pressing can be reduced, thereby improving the quality and reliability of the battery cell.

[0027] In one embodiment, after the initial active material layer is subjected to cold pressing, the flatness of the initial active material layer is less than or equal to a second preset value, wherein the second preset value is 5 μm-15 μm.

[0028] Since the flatness of the initial active material layer is less than or equal to the second preset value, and the second preset value is 5μm-15μm, the initial active material layer is relatively flat, so that the relatively flat initial active material layer provides a stable focal length for subsequent laser processing or other processing methods, which is beneficial to improving the quality and consistency of subsequent cleaning processes.

[0029] In one embodiment, the thickness of the preset layer is 5 μm-100 μm. Before forming the initial active material layer, a preset layer of a certain thickness is formed on the edge area of ​​at least one of the first surface and the second surface, which is beneficial to reduce the sum of the thickness of the initial edge part and the preset layer, and the thickness difference between the initial main part, thereby helping to improve the thickness uniformity of the intermediate of the pole piece, thereby helping to improve the quality and consistency of the subsequent process of removing the initial edge part, and also improve the quality and consistency of the subsequent glue coating process. In addition, setting the thickness of the preset layer within a suitable range is also beneficial to reducing the probability of wrinkling at the edge of the pole piece due to the excessive thickness of the preset layer.

[0030] And / or, along the direction from the main area to the edge area, the size of the preset layer is 0.5mm-15mm. In this way, the preset layer with a suitable width can well protect the current collector, reduce the over-etching at the edge of the current collector, reduce the probability of foil leakage, and reduce the excessive thickness of the active material layer in the main area due to the preset layer being too wide.

[0031] And / or, the adhesive force of the preset layer is 10N / m-50N / m. Since the preset layer has a certain adhesive force, the bonding strength between the preset layer and the current collector can be improved, thereby better reducing the probability of foil leakage at the edge of the current collector, thereby improving the quality rate of the electrode.

[0032] In one embodiment, the material of the preset layer includes an insulating material. Thus, the preset layer can be used to electrically isolate the edges of adjacent pole pieces, thereby reducing the risk of positive and negative poles of the battery cell being short-circuited, thereby improving the insulation effect and quality of the battery cell.

[0033] According to a second aspect of the present application, a battery cell is provided, which is prepared using the battery cell manufacturing method of any of the above embodiments.

[0034] According to a third aspect of the present application, a battery cell is provided, comprising a pole piece, the pole piece comprising a current collector, a preset layer and an active material layer. Along the thickness direction of the current collector, the current collector has a first surface and a second surface arranged opposite to each other; the first surface and the second surface both have a main area and two edge areas, and the two edge areas are respectively located on opposite sides of the main area along the width direction of the current collector. The edge area of ​​at least one of the first surface and the second surface is provided with a preset layer, wherein the surface of the first surface and the second surface provided with the preset layer is the target surface. The active material layer is at least provided in the main area of ​​the target surface. The thickness of the active material layer is greater than the thickness of the preset layer; the preset layer is provided on the current collector before the active material layer.

[0035] A preset layer is set on the edge area of ​​at least one of the first surface and the second surface. The preset layer located in the edge area can be used to protect the portion of the current collector located in the edge area, thereby reducing the probability of foil leakage in the edge area of ​​the current collector due to the subsequent process of clearing the initial edge portion, thereby effectively improving the quality rate of the electrode.

[0036] In one of the embodiments, the flatness of the preset layer is less than or equal to a first preset value, wherein the first preset value is 2 μm-5 μm.

[0037] In one embodiment, the flatness of the active material layer is less than or equal to a second preset value, wherein the second preset value is 5 μm-15 μm.

[0038] In one embodiment, the pole piece further includes a thickening layer, which is disposed on the side of the preset layer away from the current collector. The sum of the thickness of the thickening layer and the preset layer is H1, and the thickness of the active material layer is H2. Wherein, H1 and H2 have the same unit, and H1 and H2 satisfy the following condition: 0.95≤H1 / H2≤1.05.

[0039] According to a fourth aspect of the present application, a battery device is provided, comprising a battery cell according to any one of the above embodiments.

[0040] According to a fifth aspect of the present application, there is provided an electrical device comprising the above-mentioned battery device.

[0041] 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

[0042] 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:

[0043] Figure 1 A schematic structural diagram of a vehicle according to an embodiment of the present application is shown.

[0044] Figure 2 An exploded schematic diagram of a battery cell according to an embodiment of the present application is shown.

[0045] Figure 3 A schematic diagram (side view) of a process of manufacturing a battery cell in an embodiment of the present application is shown.

[0046] Figure 4 Another process schematic diagram (side view) of a method for manufacturing a battery cell in an embodiment of the present application is shown.

[0047] Figure 5 Another process schematic diagram (side view) of a method for manufacturing a battery cell in an embodiment of the present application is shown.

[0048] Figure 6 A schematic structural diagram of a pole piece in an embodiment of the present application is shown.

[0049] Figure 7 A schematic diagram (three-dimensional structural diagram) of a process of manufacturing a battery cell in an embodiment of the present application is shown.

[0050] Figure 8 Another process schematic diagram (stereoscopic structural schematic diagram) of a method for manufacturing a battery cell in an embodiment of the present application is shown.

[0051] Fig. 9 Another process schematic diagram (stereoscopic structural schematic diagram) of a method for manufacturing a battery cell in an embodiment of the present application is shown.

[0052] Fig.10 A schematic diagram of a process of manufacturing a battery cell in another embodiment of the present application is shown.

[0053] Fig.11 Another process schematic diagram of a method for manufacturing a battery cell in another embodiment of the present application is shown.

[0054] Fig.12 A schematic diagram of a process of manufacturing a battery cell in another embodiment of the present application is shown.

[0055] Fig.13 Another process schematic diagram of a method for manufacturing a battery cell in yet another embodiment of the present application is shown.

[0056] Figure numerals: 1, vehicle; 10, battery device; 100, electrode assembly; 110, pole piece; 111, current collector; 1111, first surface; 1112, second surface; q1, main body area; q2, edge area; 112, preset layer; 113, active material layer; 1130, initial active material layer; 1131, initial main body part; 1132, initial edge part; 114, thickening layer; 200, shell; 210, bottom shell; 220, top cover; 300, pole; 20, motor; 30, controller. DETAILED DESCRIPTION

[0057] 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.

[0058] 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.

[0059] 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.

[0060] 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.

[0061] 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.

[0062] 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.

[0063] 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 at 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 at the edge of the active material layer.

[0064] 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), resulting in foil leakage in the current collector, which in turn affects the quality rate of the pole piece.

[0065] 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. By pre-setting a preset layer in the edge area of ​​the current collector of the electrode piece of the battery cell, the part of the current collector located in the edge area can be protected, and the probability of foil leakage in the edge area of ​​the current collector due to subsequent cleaning process is reduced, thereby improving the quality rate of the electrode piece.

[0066] 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.

[0067] Figure 1A 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.

[0068] 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 .

[0069] Figure 2 An exploded schematic diagram of a battery cell according to an embodiment of the present application is shown.

[0070] See also Figure 2 A 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.

[0071] 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.

[0072] Figure 3-Figure 5 A schematic diagram (side view) showing a process of manufacturing a battery cell in an embodiment of the present application is shown. Figure 6 FIG. 1 shows a schematic diagram of the structure of a pole piece in an embodiment of the present application. Figure 7-Figure 9 A schematic diagram (three-dimensional structural diagram) of the process of manufacturing a battery cell in an embodiment of the present application is shown.

[0073] Please refer to Figure 3-Figure 5 , Figure 6 and Figure 7-Figure 9 , an embodiment of the present application provides a method for manufacturing a battery cell, including:

[0074] S10. Provide a current collector 111; wherein, 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 arranged opposite to each other; the first surface 1111 and the second surface 1112 both have a main region q1 and two edge regions q2, and the two edge regions q2 are respectively located on opposite sides of the main region q1 along the width direction of the current collector 111.

[0075] The current collector 111 is a component on the pole piece 110 for carrying the initial active material layer 1130 and for collecting the current generated by the active material layer 113. The current collector 111 may be an aluminum foil or a copper foil.

[0076] The main region q1 refers to a region on the first surface 1111 or the second surface 1112 that is located inside the edge region q2 and occupies a larger area.

[0077] The edge region q2 refers to a region on the first surface 1111 or the second surface 1112 that is located outside the main region q1, located at the edge and occupies a smaller area.

[0078] The width direction of the current collector 111 is parallel to the width direction of the pole piece 110. 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.

[0079] The strip corresponding to the electrode 110 will be cut at a certain interval along the length direction L of the electrode 110. Therefore, the two edge areas q2 are respectively connected to the opposite sides of the main area q1 along the width direction of the electrode 110, so that the active material layer 113 can be provided with the following preset layers 112 on the opposite sides along the width direction of the electrode 110, which can meet the application requirements of the scenario of "the strip corresponding to the electrode 110 is cut at a certain interval along the length direction L of the electrode 110".

[0080] S20, forming a preset layer 112 in an edge region q2 of at least one of the first surface 1111 and the second surface 1112; wherein the surface of the first surface 1111 and the second surface 1112 on which the preset layer 112 is disposed is a target surface.

[0081] The preset layer 112 refers to a material layer disposed on the edge region q2 of at least one of the first surface 1111 and the second surface 1112 of the current collector 111 and disposed before the initial active material layer 1130. The material of the preset layer 112 may include an insulating material. Specifically, the material of the preset layer 112 is an insulating material such as an insulating slurry, hot melt adhesive, ultraviolet light curing adhesive (UV adhesive) or insulating adhesive.

[0082] “Forming a predetermined layer 112 on an edge region q2 of at least one of the first surface 1111 and the second surface 1112” may be: forming a predetermined layer 112 (such as Figure 3 As shown); it can also be: forming a preset layer 112 on the edge area q2 of the second surface 1112; it can also be that the preset layer 112 is formed on the edge area q2 of the first surface 1111 and the second surface 1112 respectively.

[0083] The preset layer 112 can be formed on the edge area q2 of at least one of the first surface 1111 and the second surface 1112 by coating, or by gluing, without specific limitation.

[0084] Specifically, a first coating system can be used to form a preset layer 112 on an edge area q2 of at least one of the first surface 1111 and the second surface 1112 by coating; a first gluing system can also be used to form a preset layer 112 on an edge area q2 of at least one of the first surface 1111 and the second surface 1112 by gluing.

[0085] S30, forming an initial active material layer 1130 covering the preset layer 112 on the target surface; wherein the initial active material layer 1130 includes an initial main body portion 1131 disposed in the main body region q1, and an initial edge portion 1132 covering the preset layer 112. wherein the thickness of the preset layer 112 is less than the thickness of the initial main body portion 1131.

[0086] The initial active material layer 1130 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 and which has not been subsequently cleaned and cold-pressed compared to the active material layer 113 . The initial active material layer 1130 may include an active material, a conductive agent, a binder, and the like.

[0087] The initial body portion 1131 refers to a portion of the initial active material layer 1130 that is provided in the body region q1 .

[0088] The initial edge portion 1132 refers to a portion of the initial active material layer 1130 that is disposed in the edge region q2 and covers the preset layer 112 .

[0089] The initial active material layer 1130 covering the preset layer 112 may be formed on the target surface by coating. Specifically, the initial active material layer 1130 covering the preset layer 112 may be formed on the target surface by coating using the second coating system.

[0090] In the technical solution of the present application, a preset layer 112 is set on the edge area q2 of at least one of the first surface 1111 and the second surface 1112. The preset layer 112 located in the edge area q2 can be used to protect the portion of the current collector 111 located in the edge area q2, thereby reducing the probability of foil leakage in the edge area q2 of the current collector 111 due to the subsequent process of clearing the initial edge portion 1132, thereby effectively improving the quality rate of the electrode 110.

[0091] In some embodiments, the flatness of the preset layer 112 is less than or equal to a first preset value, wherein the first preset value is 2 μm-5 μm.

[0092] For example, the first preset value is 2 μm, 3 μm, 4 μm or 5 μm.

[0093] The flatness of the preset layer 112 is less than or equal to the first preset value, and the first preset value is 2μm-5μm. Therefore, the preset layer 112 is relatively flat, and because the thickness of the preset layer 112 located in the edge area q2 and pre-set is less than the thickness of the initial main body portion 1131 of the initial active material layer 1130, it is beneficial to reduce the sum of the thickness of the portion of the initial active material layer 1130 located in the edge area q2 (that is, the initial edge portion 1132) and the preset layer 112, and the thickness difference between the portion of the initial active material layer 1130 located in the main body area q1 (that is, the initial main body portion 1131), thereby facilitating the improvement of the electrode 1. The thickness uniformity of the intermediate 10 is beneficial to uniformly compact the intermediate of the pole piece 110, which is beneficial to improve the compaction density and quality of the pole piece 110; it can also provide a relatively flat initial edge portion 1132 with a stable focal length for subsequent laser processing or other processing methods (laser processing or other processing methods will be used to clear the initial edge portion 1132), which is beneficial to improving the quality and consistency of the subsequent clearing process; and the relatively flat preset layer 112 can also provide a size-stable position for subsequent gluing or insulation processing, which is beneficial to improving the quality and consistency of the subsequent gluing process.

[0094] In some embodiments, after step S30 of forming an initial active material layer 1130 covering the preset layer 112 on the target surface, the method for manufacturing a battery cell further includes:

[0095] S40 , performing cold pressing on the initial active material layer 1130 .

[0096] By cold pressing the initial active material layer 1130 , the serious adhesion of the pole piece 110 can be reduced, and the compaction density, adhesion and quality rate of the pole piece 110 can be improved.

[0097] In some embodiments, after the initial active material layer 1130 is cold pressed, the compaction density of the initial main body portion 1131 is m1, and the compaction density of the initial edge portion 1132 is m2, wherein m1 and m2 have the same unit and m1 and m2 satisfy the following condition: 0.9≤m2 / m1≤1.1.

[0098] Illustratively, m2 / m1 may be 0.9, 1.0 or 1.1.

[0099] Since m1 and m2 satisfy the following condition: 0.9≤m2 / m1≤1.1, the compaction density of the initial main part 1131 and the compaction density of the initial edge part 1132 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 initial active material layer 1130 of the present application is relatively high and the distribution is relatively even, which is beneficial to increase the supporting force of the pole piece 110, 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.

[0100] In some embodiments, m2 ≥ 3.0 g / cm 3 .

[0101] For example, m2 may be 3.0 g / cm 3 、3.1g / cm 3 、3.2g / cm 3 , 3.3g / cm 3 、3.4g / cm 3 , 3.5g / cm 3 or 3.6g / cm 3 wait.

[0102] In this way, compared with the compaction density at the edge of the pole piece in the related art, the compaction density of the initial active material layer 1130 of the present application is higher everywhere, which is beneficial to increase the supporting force of the pole piece 110, 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.

[0103] In some embodiments, after the initial active material layer 1130 is subjected to the cold pressing process, the adhesive force of the initial edge portion 1132 is 5 N / m-50 N / m.

[0104] Illustratively, the adhesive force of the initial edge portion 1132 may be 5 N / m, 10 N / m, 20 N / m, 30 N / m, 40 N / m, or 50 N / m.

[0105] Controlling the bonding force of the initial edge portion 1132 within an appropriate range is beneficial to improving the bonding strength between the initial edge portion 1132 and the current collector 111, and can also improve the bonding strength between the initial active material layer 1130 and the current collector 111, thereby reducing the probability of "the initial active material layer 1130 detaching from the current collector 111 or the current collector 111 leaking foil."

[0106] In some embodiments, after the step S40 of cold pressing the initial active material layer 1130 , the method for manufacturing a battery cell further includes:

[0107] S50 , removing at least a portion of the initial edge portion 1132 to obtain the active material layer 113 .

[0108] After at least part of the initial edge portion 1132 is removed, it is convenient to perform subsequent gluing processes, etc. in the area where the initial edge portion 1132 was originally located.

[0109] In some embodiments, after the step S50 of removing at least a portion of the initial edge portion 1132 , the method for manufacturing the battery cell further includes:

[0110] S60, performing a thickness reduction process on the preset layer 112 (which may be combined with Figure 5 and Fig.10 It is understood that step S60 is after step S50, which is equivalent to first forming Figure 5 The structure shown in FIG. Fig.10 structure shown).

[0111] In the actual process, during the process of laser removal of the initial edge portion 1132 , the preset layer 112 may be subjected to a thickness reduction process, that is, step S50 and step S60 may be performed in the same process.

[0112] In this way, the cleanliness of the surface of the preset layer 112 facing away from the current collector 111 can be improved, which is beneficial to the subsequent formation of the thickened layer 114 described below on the preset layer 112 .

[0113] In some embodiments, after the step S50 of removing at least a portion of the initial edge portion 1132 , the method for manufacturing the battery cell further includes:

[0114] S70 , forming a thickened layer 114 on a side of the preset layer 112 facing away from the current collector 111 .

[0115] The sum of the thicknesses of the thickened layer 114 and the preset layer 112 is H1, and the thickness of the active material layer 113 is H2, wherein H1 and H2 have the same unit, and H1 and H2 satisfy the following condition: 0.95≤H1 / H2≤1.05.

[0116] It may be that the method for manufacturing a battery cell does not include step S60, and step S70 is located after step S50; it may also be that the method for manufacturing a battery cell further includes step S60, and step S70 is located after step S60 (it may be combined with Fig.10 and Fig.11 to understand).

[0117] Illustratively, H1 / H2 may be 0.95, 1, or 1.05.

[0118] It can be understood that the active material layer 113 is provided with a stacked preset layer 112 and a thickened layer 114 on opposite sides along the width direction of the pole piece 110 .

[0119] It can be understood that H1 / H2 tends to be equal to 1, that is, the sum of the thickness of the thickened layer 114 and the preset layer 112 tends to be equal to the thickness of the active material layer 113. Therefore, the thickened layer 114 can be used to form a relatively flat pole piece 110, which can improve the force uniformity of the pole piece 110 of the battery cell during the isostatic pressing process, which is beneficial to improve the density of the battery cell.

[0120] In some embodiments, a surface of the thickened layer 114 facing away from the preset layer 112 is flush with a surface of the active material layer 113 facing away from the current collector 111 .

[0121] In this way, a relatively flat pole piece 110 can be obtained, thereby improving the force uniformity of the pole piece 110 of the battery cell during the isostatic pressing process, which is beneficial to improving the compactness of the battery cell.

[0122] In some embodiments, the material of the thickening layer 114 includes an insulating material.

[0123] In this way, the thickened layer 114 can be used to electrically isolate the edges of adjacent pole pieces 110, thereby reducing the risk of positive and negative electrode short circuits in the battery cell, thereby improving the insulation effect and quality of the battery cell.

[0124] In some embodiments, the hardness of the predetermined layer 112 is greater than the hardness of the thickened layer 114 .

[0125] On the one hand, the hardness of the preset layer 112 is relatively high, which reduces the probability of deformation of the preset layer 112 during the cold pressing process, thereby reducing the situation where the compaction density of the active material layer 113 is affected by the cold pressing deformation of the preset layer 112, thereby facilitating the improvement of the compaction density and adhesion of the active material layer 113. On the other hand, the hardness of the thickened layer 114 is relatively low, that is, the flexibility of the thickened layer 114 is relatively high, which is conducive to reducing the probability of cracking of the pole piece 110 during the isostatic pressing process, thereby improving the quality rate and reliability of the battery cell.

[0126] In some embodiments, the thickened layer 114 is elastic.

[0127] Since the thickened layer 114 is elastic, the probability of cracking of the pole piece 110 during the isostatic pressing process can be reduced, thereby improving the quality and reliability of the battery cell.

[0128] In some embodiments, after the initial active material layer 1130 is subjected to the cold pressing process, the flatness of the initial active material layer 1130 is less than or equal to a second preset value, wherein the second preset value is 5 μm-15 μm.

[0129] For example, the second preset value is 5 μm, 10 μm or 15 μm.

[0130] Since the flatness of the initial active material layer 1130 is less than or equal to the second preset value, and the second preset value is 5μm-15μm, the initial active material layer 1130 is relatively flat, so that the relatively flat initial active material layer 1130 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.

[0131] In some embodiments, the thickness of the predetermined layer 112 is 5 μm-100 μm.

[0132] For example, the thickness of the preset layer 112 is 5 μm, 10 μm, 20 μm, 30 μm, 40 μm, 50 μm, 60 μm, 70 μm, 80 μm, 90 μm or 100 μm.

[0133] Before forming the initial active material layer 1130, a preset layer 112 of a certain thickness is formed on the edge region q2 of at least one of the first surface 1111 and the second surface 1112, which is conducive to reducing the sum of the thickness of the initial edge portion 1132 and the preset layer 112, and the thickness difference between the initial main body portion 1131, thereby helping to improve the thickness uniformity of the intermediate body of the pole piece 110, thereby helping to improve the quality and consistency of the subsequent process of removing the initial edge portion 1132, and also improve the quality and consistency of the subsequent glue coating process. In addition, the thickness of the preset layer 112 is set within a suitable range, which is also conducive to reducing the probability of wrinkling at the edge of the pole piece 110 due to the excessive thickness of the preset layer 112.

[0134] In some embodiments, along the direction from the main area q1 to the edge area q2, the size of the preset layer 112 is 0.5 mm-15 mm.

[0135] For example, along the direction from the main area q1 to the edge area q2, the size of the preset layer 112 is 0.5 mm, 5 mm, 10 mm or 15 mm.

[0136] Along the direction from the main area q1 to the edge area q2, the size of the preset layer 112 is controlled within an appropriate range, i.e., 0.5 mm to 15 mm. Thus, the preset layer 112 of appropriate width can well protect the current collector 111, reduce the over-etching at the edge of the current collector 111, reduce the probability of foil leakage, and reduce the excessive thickness of the active material layer 113 located in the main area q1 due to the preset layer 112 being too wide.

[0137] In some embodiments, the adhesive force of the preset layer 112 is 10 N / m-50 N / m.

[0138] For example, the adhesive force of the preset layer 112 is 10 N / m, 20 N / m, 30 N / m, 40 N / m or 50 N / m.

[0139] Since the preset layer 112 has a certain adhesive force, the bonding strength between the preset layer 112 and the current collector 111 can be improved, thereby better reducing the probability of foil leakage at the edge of the current collector 111, thereby improving the quality rate of the electrode 110.

[0140] In some embodiments, the material of the predetermined layer 112 includes insulating material.

[0141] In this way, the preset layer 112 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 cells, thereby improving the insulation effect and quality of the battery cells.

[0142] An embodiment of the present application provides a battery cell, which is prepared using the battery cell manufacturing method of any of the above embodiments.

[0143] An embodiment of the present application also provides a battery cell, including a pole piece 110, the pole piece 110 includes a current collector 111, a preset layer 112 and an active material layer 113, along the thickness direction of the current collector 111, the current collector 111 has a first surface 1111 and a second surface 1112 arranged opposite to each other; the first surface 1111 and the second surface 1112 both have a main area q1 and two edge areas q2, and the two edge areas q2 are respectively located on opposite sides of the main area q1 along the width direction of the current collector 111. The edge area q2 of at least one of the first surface 1111 and the second surface 1112 is provided with a preset layer 112; wherein the surface of the first surface 1111 and the second surface 1112 provided with the preset layer 112 is a target surface. The active material layer 113 is at least provided in the main area q1 of the target surface; wherein the thickness of the active material layer 113 is greater than the thickness of the preset layer 112.

[0144] “The active material layer 113 is at least disposed in the main area q1 of the target surface” may be: the active material layer 113 is disposed in the main area q1 of the target surface (eg Figure 6 or Fig.11 As shown), it can also be that a portion of the active material layer 113 is disposed in the main region q1 of the target surface, and another portion of the active material layer 113 is disposed in the edge region q2 of the target surface (as shown Fig.12 and Fig.13 as shown).

[0145] A preset layer 112 is set on the edge area q2 of at least one of the first surface 1111 and the second surface 1112. The preset layer 112 located in the edge area q2 can be used to protect the portion of the current collector 111 located in the edge area q2, thereby reducing the probability of foil leakage in the current collector 111 in the edge area q2 due to the subsequent process of clearing the initial edge portion 1132, thereby effectively improving the quality rate of the electrode 110.

[0146] In some embodiments, compared with the pole piece in the related art (the flatness at the edge of the pole piece in the related art is 30 μm-100 μm, and the compaction density at the edge of the pole piece in the related art is 2.0 g / cm 3 , the bonding force at the edge of the pole piece in the related art is 0.5N / m), the flatness of the active material layer 113 of the present application is 5μm-10μm, which is conducive to significantly improving the subsequent laser cleaning and insulation glue coating rate; by measuring the weight and thickness of the active material layer 113, it is known that the compaction density of the active material layer 113 is increased to 3.6g / cm 3Through the adhesion test, it is known that the adhesion of the active material layer 113 is increased to 5N / m-50N / m. Therefore, by using the battery cell and the method for manufacturing the battery cell of the present application, the compaction density and adhesion of the active material layer 113 can be improved, and the quality rate of the electrode 110 can also be improved.

[0147] An embodiment of the present application provides a battery device 10, comprising a battery cell according to any of the above embodiments.

[0148] 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.

[0149] An embodiment of the present application provides an electrical device, including the battery device 10 described above.

[0150] 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.

[0151] 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 method for manufacturing a battery cell, characterized in that: include: A current collector (111) is provided; wherein, along the 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; the first surface (1111) and the second surface (1112) each have a main region (q1) and two edge regions (q2), and the two edge regions (q2) are respectively located on opposite sides of the main region (q1) along the width direction of the current collector (111); A preset layer (112) is formed in the edge region (q2) of at least one of the first surface (1111) and the second surface (1112); wherein the surface of the first surface (1111) and the second surface (1112) on which the preset layer (112) is provided is a target surface; forming an initial active material layer (1130) covering the preset layer (112) on the target surface; wherein the initial active material layer (1130) comprises an initial main body portion (1131) disposed in the main body region (q1), and an initial edge portion (1132) covering the preset layer (112); Wherein, the thickness of the preset layer (112) is smaller than the thickness of the initial main body part (1131); The preset layer (112) is arranged on the current collector (111) before the initial active material layer (1130); After forming an initial active material layer (1130) covering the preset layer (112) on the target surface, the method for manufacturing the battery cell further comprises: Performing a cold pressing process on the initial active material layer (1130); After the initial active material layer (1130) is subjected to cold pressing, the method for manufacturing the battery cell further comprises: removing at least a portion of the initial edge portion (1132) to obtain an active material layer (113); After removing at least part of the initial edge portion (1132), the method for manufacturing the battery cell further comprises: forming a thickening layer (114) on a side of the preset layer (112) away from the current collector (111); The material of the preset layer (112) includes insulating material; The material of the thickened layer (114) includes insulating material; The hardness of the preset layer (112) is greater than the hardness of the thickened layer (114).

2. The method for manufacturing a battery cell according to claim 1, characterized in that: The flatness of the preset layer (112) is less than or equal to a first preset value; Wherein, the first preset value is 2μm-5μm.

3. The method for manufacturing a battery cell according to claim 1, characterized in that: After the initial active material layer (1130) is subjected to cold pressing, the compaction density of the initial main body portion (1131) is m1, and the compaction density of the initial edge portion (1132) 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.

4. The method for manufacturing a battery cell according to claim 3, characterized in that: m2≥3.0g / cm 3 。 5. The method for manufacturing a battery cell according to claim 1, characterized in that: After the initial active material layer (1130) is subjected to cold pressing, the bonding force of the initial edge portion (1132) is 5N / m-50N / m.

6. The method for manufacturing a battery cell according to claim 1, characterized in that: The sum of the thicknesses of the thickened layer (114) and the preset layer (112) is H1, and the thickness of the active material layer (113) is H2; Among them, the units of H1 and H2 are the same, and H1 and H2 satisfy the following condition: 0.95≤H1 / H2≤1.

05.

7. The method for manufacturing a battery cell according to claim 6, characterized in that: H1 / H2=1; and / or A surface of the thickened layer (114) facing away from the preset layer (112) is flush with a surface of the active material layer (113) facing away from the current collector (111).

8. The method for manufacturing a battery cell according to claim 6, characterized in that: The thickened layer (114) has elasticity.

9. The method for manufacturing a battery cell according to claim 1, characterized in that: After the initial active material layer (1130) is subjected to cold pressing, the flatness of the initial active material layer (1130) is less than or equal to a second preset value; Wherein, the second preset value is 5μm-15μm.

10. The method for manufacturing a battery cell according to any one of claims 1 to 9, characterized in that: The thickness of the preset layer (112) is 5 μm-100 μm; and / or Along the direction from the main area (q1) to the edge area (q2), the size of the preset layer (112) is 0.5 mm-15 mm; and / or The adhesive force of the preset layer (112) is 10 N / m-50 N / m.

11. A battery cell, characterized in that: The battery cell is prepared by the method for preparing the battery cell according to any one of claims 1 to 10.

12. A battery cell, characterized in that: It comprises a pole piece (110), wherein the pole piece (110) comprises: A current collector (111), wherein along the 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; the first surface (1111) and the second surface (1112) each have a main region (q1) and two edge regions (q2), and the two edge regions (q2) are respectively located on opposite sides of the main region (q1) along the width direction of the current collector (111); A preset layer (112), wherein the edge region (q2) of at least one of the first surface (1111) and the second surface (1112) is provided with the preset layer (112); wherein the surface of the first surface (1111) and the second surface (1112) on which the preset layer (112) is provided is a target surface; an active material layer (113), which is at least provided in the main region (q1) of the target surface; wherein the thickness of the active material layer (113) is greater than the thickness of the preset layer (112); The preset layer (112) is arranged on the current collector (111) before the active material layer (113); The pole piece (110) further includes a thickened layer (114); The thickened layer (114) is arranged on a side of the preset layer (112) facing away from the current collector (111); The material of the preset layer (112) includes insulating material; The material of the thickened layer (114) includes insulating material; The hardness of the preset layer (112) is greater than the hardness of the thickened layer (114).

13. The battery cell according to claim 12, characterized in that: The flatness of the preset layer (112) is less than or equal to a first preset value; Wherein, the first preset value is 2μm-5μm.

14. The battery cell according to claim 12, characterized in that: The flatness of the active material layer (113) is less than or equal to a second preset value; Wherein, the second preset value is 5μm-15μm.

15. The battery cell according to claim 12, characterized in that: The sum of the thicknesses of the thickened layer (114) and the preset layer (112) is H1, and the thickness of the active material layer (113) is H2; Among them, the units of H1 and H2 are the same, and H1 and H2 satisfy the following condition: 0.95≤H1 / H2≤1.

05.

16. A battery device, characterized in that: Comprising a battery cell as claimed in any one of claims 11 to 15.

17. An electrical equipment, characterized in that: Comprising the battery device as claimed in claim 16.

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