Method for manufacturing battery cell, end cap assembly, battery cell, and battery device

Abstract

The application discloses a battery cell manufacturing method, an end cover assembly, a battery cell and a battery device. The battery cell manufacturing method comprises the following steps: determining a target film according to a current type of electrolyte of a battery cell, wherein the target film is not corroded when the target film is provided with the electrolyte of the current type; determining a processing parameter according to a structure parameter of a coding area of the battery cell; processing the target film into a protective film according to the processing parameter; and bonding the protective film to an outer surface of the battery cell, so that the coding area is covered by the protective film. When the electrolyte splashes, the electrolyte cannot fall on the coding area due to the shielding of the coding area by the protective film, so that the electrolyte corrosion of the coding area is effectively reduced, the coding area can be effectively identified, and the qualified rate of the battery cell is effectively improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of battery manufacturing, and in particular to a manufacturing method of a battery monomer, an end cover assembly, a battery monomer and a battery device. BACKGROUND

[0002] With the development of new energy, more and more fields use new energy as power. Due to the advantages of high energy density, recyclable charging, safety and environmental protection, battery devices are widely used in new energy vehicles, consumer electronics, energy storage systems and other fields.

[0003] In the related art, a battery device includes a battery monomer, and the battery monomer is provided with a code area. In the manufacturing process of the battery monomer, the code area is easily corroded by electrolyte, so that the code area cannot be identified. SUMMARY

[0004] In view of the above problems, the present application provides a manufacturing method of a battery monomer, an end cover assembly, a battery monomer and a battery device, which solves the problem of electrolyte corrosion of the code area.

[0005] The first aspect of the present application provides a manufacturing method of a battery monomer, which includes:

[0006] According to the current type of electrolyte of the battery monomer, a target film is determined, wherein the target film is not corroded when the target film is provided with the electrolyte of the current type;

[0007] According to the structure parameters of the code area of the battery monomer, a processing parameter is determined;

[0008] According to the processing parameter, the target film is processed into a protective film;

[0009] The protective film is bonded to the outer surface of the battery monomer, so that the code area is covered by the protective film.

[0010] Specifically, according to the current type of electrolyte of the processed battery monomer, a target film that is suitable for the electrolyte is selected, i.e. the target film cannot be corroded by the electrolyte, and the target film is processed into a protective film required by the battery monomer, and then the processed protective film is pasted to the outer surface of the battery monomer and covers the code area, so that the code area is isolated from the outside. When the electrolyte splashes, the electrolyte cannot fall on the code area due to the shielding of the protective film on the code area, thereby effectively reducing the occurrence of electrolyte corrosion of the code area, so that the code area can be effectively identified, thereby effectively improving the yield of the battery monomer.

[0011] In some embodiments of the present application, according to the current type of electrolyte of the battery monomer, the target film is determined, including:

[0012] acquire a current type of electrolyte of the battery cell;

[0013] According to the current type of electrolyte, a plurality of sample films are prepared, wherein at least the materials of the plurality of sample films are different;

[0014] The plurality of sample films are tested, and the target film is determined from the plurality of sample films according to the test data.

[0015] Specifically, according to the current type of electrolyte of the battery cell, a plurality of sample films with different materials are prepared, and the plurality of sample films are tested, and the target film is determined according to the test data. In this way, the target film can be effectively matched with the battery cell, thereby reducing the corrosion of the coded area after the electrolyte corrodes the protective film.

[0016] In some embodiments of the present application, testing the plurality of sample films and determining the target film from the plurality of sample films according to the test data comprises:

[0017] Corrosion testing of the plurality of sample films is performed using the current type of electrolyte;

[0018] According to the sample film not being corroded by the current type of electrolyte, a preliminary qualified sample film is determined from the plurality of sample films;

[0019] The preliminary qualified sample film is reviewed, and the target film is determined from the preliminary qualified sample film according to the review parameters meeting the design requirements, wherein the design requirements include at least one of light transmittance, thickness, temperature resistance, release force, and insulation.

[0020] Specifically, in the process of testing the plurality of sample films, the corrosion test can directly screen out sample films that can resist the electrolyte of the battery cell. The screened sample films are reviewed, and the sample films that pass the review are determined as the target film. In this way, the quality of the protective film can be effectively improved, so that the protective film can meet the current use requirements of the battery cell.

[0021] In some embodiments of the present application, in the step of reviewing the preliminary qualified sample film and determining the target film from the preliminary qualified sample film according to the review parameters meeting the design requirements, comprising:

[0022] The light transmittance of the preliminary qualified sample film is tested, and the sample film with qualified light transmittance is determined according to the light transmittance of the sample film being greater than or equal to a first threshold value;

[0023] The thickness of the preliminary qualified sample film is tested, and the sample film with qualified thickness is determined according to the thickness of the sample film being less than or equal to a second threshold value;

[0024] The temperature resistance of the preliminary qualified sample film is tested, and the sample film with qualified temperature resistance is determined according to the temperature resistance of the sample film being greater than or equal to a third threshold value;

[0025] test the release force of the sample film that passes the preliminary test, and determine a sample film with a qualified release force according to the release force of the sample film being greater than or equal to a fourth threshold value;

[0026] test the insulation of the sample film that passes the preliminary test, and determine a sample film with a qualified resistance according to the resistance value of the sample film being greater than or equal to a fifth threshold value.

[0027] Specifically, when reviewing the sample film that passes the preliminary test, the light transmittance, thickness, temperature resistance, release force and insulation of the sample film that passes the preliminary test are tested respectively, so that the light transmittance, thickness, temperature resistance, release force and insulation of the determined target film meet the use requirements of the battery monomer, and the protective film can be effectively adapted to the battery monomer.

[0028] In some embodiments of the present application, the first threshold value is greater than or equal to 50% and less than or equal to 100%. In this way, the protective film can have good light transmittance, reducing the shielding of the coding area of the battery monomer, so as to realize effective identification of the coding area, thereby meeting the production requirements.

[0029] In some embodiments of the present application, the second threshold value is greater than 0 microns and less than or equal to 150 microns. In this way, the thickness of the protective film can be effectively controlled on the basis of resisting corrosion of the electrolyte, thereby reducing the space occupied by the protective film and the manufacturing cost of the protective film.

[0030] In some embodiments of the present application, the third threshold value is greater than or equal to 300 degrees Celsius and less than or equal to 400 degrees Celsius. In this way, the protective film can have the ability to resist high temperature, so as to reduce the adverse effects of welding heat on the protective film during welding of the battery monomer.

[0031] In some embodiments of the present application, the fourth threshold value is greater than or equal to 1 N / 25 mm and less than or equal to 10 N / 25 mm. In this way, the protective film can have good structural strength after being pasted, reducing the situation that the protective film falls off.

[0032] In some embodiments of the present application, the fifth threshold value is greater than 10 to the power of 5 ohms and less than or equal to 10 to the power of 10 ohms. In this way, the protective film can have good insulation, reducing the situation that the protective film conducts electricity and causes short circuit of other components.

[0033] In some embodiments of the present application, the processing parameters are determined according to the structural parameters of the coding area of the battery monomer, the structural parameters including the shape of the coding area and the size of the coding area, and the processing parameters including the shape of the protective film and the size of the protective film, wherein the shape of the protective film is consistent with the shape of the coding area, and the size of the protective film is greater than or equal to the size of the coding area.

[0034] In this way, the protective film can be effectively matched with the coding area, the use amount of the protective film can be reduced on the basis of effectively protecting the coding area, and the manufacturing cost of the battery monomer can be reduced.

[0035] In some embodiments of the present application, when the protective film is pasted on the outer surface of the battery monomer, all the coding areas are covered by the protective film, and the minimum distance between the edges of the coding areas and the edges of the protective film is greater than or equal to 0 mm and less than or equal to 2 mm.

[0036] In this way, the protective film can be effectively matched with the coding area, the use amount of the protective film can be reduced on the basis of effectively protecting the coding area, and the manufacturing cost of the battery monomer can be reduced.

[0037] In some embodiments of the present application, the target film is processed into a protective film according to the processing parameters, and the way of processing the target film into a protective film is cutting.

[0038] In this way, the target film can be processed, the processing efficiency can be effectively improved, and the production rhythm can be accelerated.

[0039] In some embodiments of the present application, the protective film is adhered to the outer surface of the battery monomer to cover the coding area, comprising:

[0040] Receiving and fixing the battery monomer;

[0041] Obtaining the current state of the outer surface of the battery monomer with the coding area;

[0042] According to that no electrolyte is left on the outer surface of the battery monomer with the coding area, the protective film is pasted on the outer surface of the battery monomer to cover all the coding areas.

[0043] Specifically, when the protective film is pasted on the battery monomer, the battery monomer is first fixed, then it is detected whether the surface of the battery monomer with the coding area is left with electrolyte, and the protective film is pasted on the battery monomer after it is determined that no electrolyte is left, so as to reduce the case that electrolyte is left between the protective film and the battery monomer.

[0044] In some embodiments of the present application, according to that no electrolyte is left on the outer surface of the battery monomer with the coding area, the protective film is pasted on the outer surface of the battery monomer to cover all the coding areas, comprising:

[0045] Obtaining the current position of the coding area;

[0046] Controlling the protective film to be arranged above the coding area;

[0047] The protective film is controlled to rotate around a preset rotation axis to adjust the angle of the protective film, wherein the preset rotation axis is perpendicular to the plane on which the coded area is located.

[0048] The protective film is controlled to translate to enable the projection of the protective film on the battery monomer to cover the entire coded area, wherein the translation direction of the protective film is parallel to the coded area.

[0049] The protective film is controlled to be pasted onto the outer surface of the battery monomer to cover the entire coded area.

[0050] Specifically, by controlling the angle and position of the protective film, the pasting accuracy of the protective film can be effectively improved, so that the protective film can effectively protect the coded area and further reduce the corrosion of the electrolyte on the coded area.

[0051] In some embodiments of the present application, the protective film is controlled to be pasted onto the outer surface of the battery monomer to cover the entire coded area, comprising:

[0052] The protective film is controlled to be pasted onto the outer surface of the battery monomer;

[0053] A preset pressure is applied to the side of the protective film away from the battery monomer;

[0054] According to the preset duration of the pressure applied to the protective film reaching a preset duration, the preset pressure applied to the protective film is removed.

[0055] Specifically, during the pasting of the protective film, the preset pressure and the preset duration are set, so that the protective film is pasted under the action of the pasting pressure, thereby improving the pasting strength of the protective film and further reducing the situation of the protective film falling off.

[0056] In some embodiments of the present application, the pressure generated by the preset pressure on the protective film is in the range of 0.4 MPa to 0.6 MPa.

[0057] Specifically, during the pasting of the protective film, the pressure generated by the preset pressure on the protective film is set in the range of 0.4 MPa to 0.6 MPa, so that the protective film has sufficient pasting strength during the pasting of the protective film, and the situation of the battery monomer being squeezed and deformed is reduced.

[0058] In some embodiments of the present application, the preset duration is in the range of 5 seconds to 25 seconds. Specifically, by setting the preset duration in the range of 5 seconds to 25 seconds, the protective film and the battery monomer have good pasting strength during the pasting of the protective film, thereby further improving the pasting effect of the battery monomer.

[0059] The second aspect of the present application proposes an end cover assembly, comprising:

[0060] The end cover is provided with a code area on the outer surface thereof;

[0061] The protective film is the protective film as above, and is pasted on the outer surface of the end cover and covers the code area.

[0062] Specifically, in the processing of the battery monomer, according to the current type of the electrolyte of the processed battery monomer, a target film that is adapted to the electrolyte is selected, i.e., the target film cannot be corroded by the electrolyte, and the target film is processed into a protective film required by the battery monomer, and then the processed protective film is pasted to the outer surface of the battery monomer and covers the code area, so that the code area is isolated from the outside world. When the electrolyte splashes, the electrolyte cannot fall on the code area due to the shielding of the protective film on the code area, thereby effectively reducing the occurrence of the electrolyte corroding the code area, so that the code area can be effectively identified, thereby effectively improving the qualified rate of the battery monomer.

[0063] The third aspect of the present application provides a battery monomer manufactured by the battery production line as above.

[0064] Specifically, in the processing of the battery monomer, according to the current type of the electrolyte of the processed battery monomer, a target film that is adapted to the electrolyte is selected, i.e., the target film cannot be corroded by the electrolyte, and the target film is processed into a protective film required by the battery monomer, and then the processed protective film is pasted to the outer surface of the battery monomer and covers the code area, so that the code area is isolated from the outside world. When the electrolyte splashes, the electrolyte cannot fall on the code area due to the shielding of the protective film on the code area, thereby effectively reducing the occurrence of the electrolyte corroding the code area, so that the code area can be effectively identified, thereby effectively improving the qualified rate of the battery monomer.

[0065] The fourth aspect of the present application provides a battery device comprising the battery monomer as above.

[0066] Specifically, in the processing of the battery monomer, according to the current type of the electrolyte of the processed battery monomer, a target film that is adapted to the electrolyte is selected, i.e., the target film cannot be corroded by the electrolyte, and the target film is processed into a protective film required by the battery monomer, and then the processed protective film is pasted to the outer surface of the battery monomer and covers the code area, so that the code area is isolated from the outside world. When the electrolyte splashes, the electrolyte cannot fall on the code area due to the shielding of the protective film on the code area, thereby effectively reducing the occurrence of the electrolyte corroding the code area, so that the code area can be effectively identified, thereby effectively improving the qualified rate of the battery monomer.

[0067] The above description is only a summary of the technical scheme of the present application. In order to make the technical means of the present application more clearly understood and implemented according to the content of the description, and in order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the following specific embodiments of the present application are described. BRIEF DESCRIPTION OF DRAWINGS

[0068] Figure 1 A structural schematic diagram of a battery device according to an embodiment of the present application is schematically shown;

[0069] Figure 2 A partial structural schematic diagram of a battery device according to an embodiment of the present application is schematically shown;

[0070] Figure 3 A partial structural schematic diagram of a battery device according to an embodiment of the present application is schematically shown;

[0071] Figure 4 A flowchart of a manufacturing method of a battery cell according to an embodiment of the present application is schematically shown.

[0072] The reference signs are as follows:

[0073] 100, battery device;

[0074] 110, battery cell assembly;

[0075] 10, battery cell;

[0076] 11, shell; 111, end cap; 112, housing; 12, electrode terminal; 13, liquid injection hole; 14, pressure relief mechanism; 15, protective film; 16, code carving area;

[0077] 120, box;

[0078] 121, first box; 122, second box;

[0079] a, first distance; b, second distance. DETAILED DESCRIPTION

[0080] The embodiments of the technical scheme of the present application will be described in detail below with reference to the drawings. The following embodiments are only used to more clearly illustrate the technical scheme of the present application, and therefore only serve as examples, and cannot limit the protection scope of the present application.

[0081] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of this application; the use of the terms "including," "comprising," or "having" and variations thereof herein is intended to be broad and encompass the terms "consisting of" and "consisting essentially of" and variations thereof. Unless otherwise noted, the terms "including" and "comprising" are open-ended and do not exclude the presence of unrecited elements or limitations.

[0082] In the description of the embodiments of the present application, the technical terms "first", "second", and the like are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the technical features indicated. In the description of the embodiments of the present application, the meaning of "plurality" is two or more, unless otherwise explicitly and specifically limited.

[0083] Reference herein to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the application. The appearance of the phrase in various places in the specification does not necessarily all refer to the same embodiment, nor is it necessarily independent or alternative embodiments to each other. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0084] In the description of the embodiments of the present application, the term "and / or" is only a description of the association relationship of the associated objects, which means that there can be three relationships, for example, A and / or B, which can represent the three cases of A alone, A and B together, and B alone. In addition, the character " / " in this paper generally represents that the front and rear associated objects are a "or" relationship.

[0085] In the description of the embodiments of the present application, the term "plurality" refers to two or more (including two), and similarly, "multiple groups" refers to two or more groups (including two groups), and "multiple pieces" refers to two or more pieces (including two pieces).

[0086] In the description of the embodiments of the present application, the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, which is only for the convenience of describing the embodiments of the present application and simplifying the description, and is not intended to indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the embodiments of the present application.

[0087] In the description of the embodiments of the present application, unless specifically defined and limited otherwise, the terms "mounting", "connection", "connecting", "fixing" and the like should be interpreted broadly, for example, can be fixed connection, can also be detachable connection, or integral; can be mechanical connection, can also be electrical connection; can be direct connection, can also be indirect connection through an intermediate medium, can be internal communication of two elements or interaction relationship between two elements. For those skilled in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0088] At present, from the development of market situation, the application of battery device is more and more widely. The battery device is not only applied to the energy storage power supply system of hydropower, thermal power, wind power and solar power station, but also widely used in electric bicycles, electric motorcycles, electric vehicles and other electric vehicles, military equipment, aerospace and other fields. With the continuous expansion of the application field of battery device, the demand of its market is also increasing.

[0089] In the related art, the battery device includes a battery monomer, and the battery monomer is provided with a code area. In the manufacturing process of the battery monomer, the electrolyte is prone to corrode the code area, so that the code area cannot be identified.

[0090] In the present application, in the manufacturing process of the battery monomer, according to the current type of the electrolyte of the battery monomer, the target film is determined, wherein when the target film is provided with the electrolyte of the current type, the target film is not corroded, according to the structure parameters of the code area of the battery monomer, the processing parameters are determined, according to the processing parameters, the target film is processed into a protective film, and the protective film is bonded to the outer surface of the battery monomer, so that the code area is covered by the protective film. When the electrolyte splashes, the electrolyte cannot fall on the code area due to the shielding of the protective film on the code area, thereby effectively reducing the corrosion of the electrolyte on the code area, so that the code area can be effectively identified, thereby effectively improving the qualified rate of the battery monomer.

[0091] The technical solutions described in the embodiments of the present application are not only limited to the above described devices, but also can be applied to all devices using battery devices, but for the sake of simplicity of description, the following embodiments are described by taking electric vehicles as an example.

[0092] For example, the vehicle can be a gasoline car, a gas car, or a new energy car, and the new energy car can be a pure electric car, a hybrid car, or an extended-range car, etc. The vehicle can be provided with a motor, a controller, and a battery device, and the controller can be used to control the battery device to supply power to the motor. For example, the battery device can be arranged at the bottom, the front, or the rear of the vehicle. The battery device can be used for power supply of the vehicle, for example, the battery device can be used as an operating power source of the vehicle, and can be used for circuit systems of the vehicle, for example, for power demand of the vehicle during starting, navigation, and operation. In another embodiment of the present application, the battery device can not only be used as an operating power source of the vehicle, but also can be used as a driving power source of the vehicle, to replace or partially replace fuel or natural gas to provide driving power for the vehicle.

[0093] As shown in Figure 1 , the battery device 100 mentioned in the embodiments of the present application can include one or more battery cell assemblies 110 for providing voltage and capacity. The battery cell assembly 110 can include a plurality of battery cells 10 connected in series, in parallel, or in a mixed connection mode through a busbar component.

[0094] In some embodiments, the battery cell assembly 110 is usually formed by arranging a plurality of battery cells 10.

[0095] As an example, the battery cell assembly 110 can be a battery module formed by arranging and fixing a plurality of battery cells 10 into an independent module. As an example, the battery module can be formed by bundling a plurality of battery cells 10 with a cable tie.

[0096] In some embodiments, as shown in Figure 2 , the battery device 100 can be a battery pack including a box 120 and one or more battery cell assemblies 110, and the battery cell assemblies 110 are accommodated in the box 120.

[0097] As an example, the battery cell assembly 110 can be a battery module, and the battery cell assembly 110 can be accommodated in the box 120 by fixing the battery module in the box 120.

[0098] As an example, the battery cell assembly 110 can also be accommodated in the box 120 by directly fixing a plurality of battery cells 10 in the box 120.

[0099] As an example, the case 120 can include a first case 121 and a second case 122. The first case 121 and the second case 122 are fastened so that an enclosed space is formed inside the case 120 to accommodate the battery cell assembly 110. The enclosed here means covered or closed, which can be sealed or unsealed. The first case 121 can be a top cover or a bottom plate.

[0100] As an example, the case 120 can include a top cover, a frame, and a bottom plate. The top cover and the bottom plate are connected with the frame, respectively, so that an enclosed space is formed inside the case 120 to accommodate the battery cell assembly 110.

[0101] In some embodiments, the case 120 can be part of a chassis structure of a vehicle. For example, part of the case 120 can be at least part of a floor of the vehicle, or part of the case 120 can be at least part of a cross beam and a longitudinal beam of the vehicle.

[0102] The technical solutions described in the embodiments of the present application are applicable to various electric devices using the battery cell 10, such as mobile phones, portable devices, notebook computers, electric vehicles, electric toys, electric tools, vehicles, ships, and spacecraft, such as aircraft, rockets, space shuttles, and spacecraft.

[0103] In some embodiments of the present application, the battery cell 10 can be a secondary battery, which means that the battery cell 10 can be activated by charging after discharging.

[0104] The battery cell 10 can be a lithium-ion battery, a sodium-ion battery, a sodium-lithium-ion battery, a lithium-metal battery, a sodium-metal battery, a lithium-sulfur battery, a magnesium-ion battery, a nickel-hydrogen battery, a nickel-cadmium battery, a lead-acid battery, etc. The embodiments of the present application are not limited in this regard.

[0105] In some embodiments of the present application, as shown in Figure 2 and Figure 3 The battery cell 10 includes a housing 11, a pressure relief mechanism, an electrode assembly, and an insulating member. The housing includes a plurality of side walls, including a first side wall, and the pressure relief mechanism is disposed on the first side wall. The pressure relief mechanism is configured to open or close according to whether the internal pressure of the housing reaches a pressure threshold. The electrode assembly is disposed inside the housing, and the insulating member is disposed inside the housing and between the housing and the electrode assembly to insulate and isolate the housing and the electrode assembly. The insulating member abuts the electrode assembly.

[0106] As an example, the battery cell 10 can be a cylindrical battery cell, a prismatic battery cell, a soft-pack battery cell, or a battery cell of other shapes. The prismatic battery cell includes a square battery cell, a blade-shaped battery cell, and a multi-prismatic battery cell, such as a hexagonal battery cell, etc. The present application is not particularly limited.

[0107] The electrode assembly includes a positive electrode, a negative electrode, and a separator disposed between the negative electrode and the positive electrode. During charging and discharging of the battery cell 10, active ions (e.g., lithium ions) are intercalated and deintercalated between the positive electrode and the negative electrode. The separator, which is disposed between the positive electrode and the negative electrode, can function to prevent short-circuiting of the positive and negative electrodes while allowing the active ions to pass through.

[0108] In some embodiments, the positive electrode can be a positive electrode sheet, which can include a positive electrode current collector and a positive electrode active material disposed on at least one surface of the positive electrode current collector.

[0109] As an example, the positive electrode current collector has two surfaces opposite in the thickness direction thereof, and the positive electrode active material is disposed on either one or both of the two opposite surfaces of the positive electrode current collector.

[0110] As an example, the positive electrode current collector can be a metal foil, a conductive polymer material, a carbon material, or a composite current collector. For example, as the metal foil, a pure metal, an alloy, a surface-treated metal, including but not limited to stainless steel, copper, aluminum, nickel, titanium, or silver, etc. can be used. The composite current collector can include a polymer material base layer and a metal layer. The composite current collector can be formed by forming a metal material (aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver, and silver alloy, etc.) on a polymer material base material (e.g., a base material of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0111] As an example, the positive electrode active material can include at least one of a lithium-containing phosphate, a lithium transition metal oxide, and a modified compound of each thereof. However, the present application is not limited to these materials, and other conventional materials that can be used as a battery positive electrode active material can also be used. These positive electrode active materials can be used alone or in combination of two or more. As an example of the lithium-containing phosphate, at least one of lithium iron phosphate (e.g., LiFeP04(also referred to as LFP)), a composite material of lithium iron phosphate and carbon, lithium manganese phosphate (e.g., LiMnP04), a composite material of lithium manganese phosphate and carbon, lithium manganese iron phosphate, and a composite material of lithium manganese iron phosphate and carbon can be used, but the present application is not limited thereto. As an example of the lithium transition metal oxide, at least one of lithium cobalt oxide (e.g., LiCo02), lithium nickel oxide (e.g., LiNi02), lithium manganese oxide (e.g., LiMn02, LiMn204), lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, lithium nickel cobalt manganese oxide (e.g., LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 O2(also referred to as NCM 333 ), LiNi 0.5 Co 0.2 Mn0.3 O2(also can be referred to as NCM 523 ), LiNi 0.5 Co 0.25 Mn 0.25 O2(also can be referred to as NCM 211 ), LiNi 0.6 Co 0.2 Mn 0.2 O2(also can be referred to as NCM 622 ), LiNi 0.8 Co 0.1 Mn 0.1 O2(also can be referred to as NCM 811 ), lithium nickel cobalt aluminum oxide (such as LiNi 0.8 Co 0.15 Al 0.05 O2), and modified compounds thereof. The modified compounds refer to substances obtained by modification means such as doping or coating on the basis of the above-mentioned substances.

[0112] In some embodiments, the positive electrode can adopt a foam metal. The foam metal can be a foam nickel, a foam copper, a foam aluminum, a foam alloy, or a foam carbon, etc. When the foam metal is used as the positive electrode, the foam metal surface can not be provided with the positive electrode active material, of course, the positive electrode active material can also be provided. As an example, the positive electrode active material is filled or / and deposited in the foam metal.

[0113] In some embodiments, the negative electrode can be a negative electrode sheet, and the negative electrode sheet can include a negative electrode current collector.

[0114] As an example, the negative electrode current collector can adopt a metal foil, a conductive polymer material, a carbon material, or a composite current collector. For example, as the metal foil, a pure metal, an alloy, a surface-treated metal, including but not limited to stainless steel, copper, aluminum, nickel, titanium, or silver, etc. can be adopted. The composite current collector can include a polymer material base layer and a metal layer. The composite current collector can be formed by forming a metal material (copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver, and silver alloy, etc.) on a polymer material base material (such as a base material of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0115] As an example, the negative electrode sheet can include the negative electrode current collector and the negative electrode active material provided on at least one surface of the negative electrode current collector.

[0116] As an example, the negative electrode current collector has two opposite surfaces in the thickness direction of itself, and the negative electrode active material is provided on any one or both of the two opposite surfaces of the negative electrode current collector.

[0117] As an example, the negative active material can employ a negative active material for the battery cell 10 that is publicly known in the art. As an example, the negative active material can include at least one of artificial graphite, natural graphite, soft carbon, hard carbon, a silicon-based material, a tin-based material, and lithium titanate, etc. The silicon-based material can be selected from at least one of elemental silicon, a silicon oxide compound, a silicon-carbon composite, a silicon-nitrogen composite, and a silicon alloy. The tin-based material can be selected from at least one of elemental tin, a tin oxide compound, and a tin alloy. However, the present application is not limited to these materials, and other conventional materials that can be used as a negative active material for the battery cell 10 can also be used. These negative active materials can be used alone or in combination of two or more.

[0118] In some embodiments, the negative electrode can employ a foamed metal. The foamed metal can be foamed nickel, foamed copper, foamed aluminum, foamed alloy, or foamed carbon, etc. When the foamed metal is used as a negative electrode sheet, the foamed metal surface can not be provided with a negative active material, or can be provided with a negative active material.

[0119] As an example, the negative active material can be filled or / and deposited in the negative current collector.

[0120] In some embodiments, the material of the positive current collector can be aluminum, and the material of the negative current collector can be copper.

[0121] In some embodiments, the electrode assembly further includes a separator disposed between the positive electrode and the negative electrode.

[0122] In some embodiments, the separator is a separator film. The type of the separator film is not particularly limited in the present application, and any publicly known porous structure separator film having good chemical stability and mechanical stability can be used.

[0123] As an example, the main material of the separator film can be selected from at least one of glass fiber, non-woven fabric, polyethylene, polypropylene, and polyvinylidene fluoride, and ceramic. The separator film can be a single layer film or a multi-layer composite film, and is not particularly limited. When the separator film is a multi-layer composite film, the materials of the respective layers can be the same or different, and are not particularly limited. The separator can be a separate component located between the positive electrode and the negative electrode, or can be attached to the surface of the positive electrode and the negative electrode. An inorganic particle coating layer, an organic particle coating layer, or an organic / inorganic composite coating layer can be applied to the surface of the separator film.

[0124] In some embodiments, the separator is a solid-state electrolyte. The solid-state electrolyte is disposed between the positive electrode and the negative electrode, and functions to transport ions and separate the positive electrode and the negative electrode.

[0125] The electrode assembly can have a roll structure, a stack structure, or a hybrid structure of the roll and the stack.

[0126] In some embodiments, the electrode assembly is a wound structure, wherein the positive electrode sheet and the negative electrode sheet are wound into the wound structure.

[0127] In some embodiments, the electrode assembly is a laminate structure.

[0128] As an example, multiple positive electrode sheets and multiple negative electrode sheets can be provided respectively, and the multiple positive electrode sheets and the multiple negative electrode sheets can be alternately stacked.

[0129] As an example, a plurality of positive electrode sheets may be provided, and the negative electrode sheet may be folded to form a plurality of stacked folded segments, with a positive electrode sheet being sandwiched between adjacent folded segments.

[0130] As an example, both the positive electrode sheet and the negative electrode sheet are folded to form a plurality of stacked folded segments.

[0131] As an example, a plurality of separators may be provided, each of which is disposed between any adjacent positive electrode sheets or negative electrode sheets.

[0132] As an example, the separator may be provided continuously, and may be provided between any adjacent positive electrode sheets or negative electrode sheets by folding or winding.

[0133] In some embodiments, the shape of the electrode assembly can be cylindrical, flat, or polygonal.

[0134] In some embodiments, the electrode assembly is provided with a tab, which can conduct current from the electrode assembly. The tab includes a positive tab and a negative tab.

[0135] In some embodiments, as Figure 2 and Figure 3 As shown, a pressure relief mechanism 14 is provided on the housing 11 . The pressure relief mechanism 14 is used to discharge the internal gas of the battery cell 10 .

[0136] For example, when the internal pressure or temperature of the battery cell 10 reaches a predetermined threshold, the pressure relief mechanism 14 is activated to release the internal pressure or temperature. When the internal pressure or temperature of the battery cell 10 reaches the predetermined threshold, the pressure relief mechanism 14 actuates or a weakened structure within the pressure relief mechanism 14 is destroyed, thereby forming an opening or channel for the internal pressure or temperature to be released. The threshold design varies depending on the design requirements. The threshold may depend on the material of one or more of the positive electrode sheet, negative electrode sheet, electrolyte, and separator in the battery cell 10.

[0137] As an example, the pressure relief mechanism 14 may be integrally formed with the housing 11 .

[0138] As an example, the pressure relief mechanism 14 may also be provided separately from and connected to the housing 11 .

[0139] "actuated" as used herein refers to the action or activation of the pressure relief mechanism to a state in which the internal pressure and temperature of the battery cell 10 can be released. The action of the pressure relief mechanism 14 can include, but is not limited to, the movement of components in the pressure relief mechanism 14 to form an exhaust passage, the breaking, shattering, tearing or opening of at least a portion of the pressure relief mechanism 14, and the like. When the pressure relief mechanism 14 is actuated, the high temperature and pressure material inside the battery cell 10 can be discharged as exhaust from the actuated portion. In this way, the battery cell 10 can be depressurized and cooled at a controllable pressure or temperature, thereby reducing the potential for more severe accidents.

[0140] In some embodiments, when the housing 11 is not a sealed structure, the pressure relief mechanism 14 can be provided as a through hole for discharging the gas inside the battery cell 10.

[0141] The exhaust from the battery cell 10 as used herein includes, but is not limited to, electrolyte, dissolved or split positive and negative electrode sheets, fragments of separators, high temperature and pressure gases generated by reactions, flames, and the like.

[0142] The positive and negative tabs can be led out from the same end of the electrode sheet, or can be led out from opposite ends of the electrode sheet, respectively.

[0143] The positive and negative tabs can have the same or different structures. Taking the positive tab as an example, the positive tab can include a plurality of positive tab layers stacked together to form the positive tab. The positive tab can include at least two portions, one of which is located between the main body portion of the electrode sheet and the insulating member, and the other of which is located between the insulating member and the electrode lead-out member.

[0144] The insulating member can insulate at least a portion of the tab from the end surface of the main body portion, thereby reducing the risk of the tab being inserted into the main body portion when the battery cell 10 is affected by external impact, vibration, and the like, thereby reducing the risk of short circuit of the battery cell 10 and improving the reliability of the battery cell 10.

[0145] The insulating member can be a one-piece structure or a split structure. As an example, the insulating member is connected by a plurality of independently formed parts. As another example, the insulating member is integrally formed by stamping.

[0146] For example, the insulating member is a plastic member, and the plastic member is integrally formed by injection molding. The plastic member is convenient to process, and the manufacturing cost of the plastic member is relatively low.

[0147] In some embodiments of the present application, as Figure 2 and Figure 3As shown, the shell 11 includes a shell body 112 having an opening and an end cap 111 connected to the shell body 112 and closing the opening, the end cap 111 constituting a first side wall, and the pressure relief mechanism 14 is arranged on the end cap.

[0148] In some embodiments of the present application, the shell 11 can be a steel shell, an aluminum shell, a plastic shell (such as polypropylene), a composite metal shell (such as a copper-aluminum composite shell), or an aluminum-plastic film, etc. In some embodiments, the shell 11 can be a sealed structure or a non-sealed structure. As an example, when the shell 11 is a non-sealed structure, the shell 11 serves to protect the electrode assembly, and a sealing bag is further arranged between the shell 11 and the electrode assembly, which is used to package the electrode assembly and the electrolyte. Specifically, the sealing bag can be a bag-shaped insulating member or an aluminum-plastic film. When the shell 11 is a sealed structure, it is used to package the electrode assembly, the electrolyte, etc. The shell body 112 can be provided with one or more openings. The end cap 111 can also be provided with one or more openings.

[0149] In addition, the connection between the end cap 111 and the shell body 112 includes but is not limited to clamping, bonding, welding, or connecting through a connecting member.

[0150] In some embodiments of the present application, as shown in Figure 2 and Figure 3 The battery cell 10 further includes an electrode terminal 12 arranged on the end cap and electrically connected to the electrode assembly. The electrode terminal 12 is electrically connected to the tab of the electrode assembly. The electrode terminal 12 can be directly connected to the tab or indirectly connected to the tab through a current collecting member. The electrode terminal 12 can be arranged on the end cap 111 or on the shell body 112. In the embodiments shown in the present application, the electrode terminal 12 is arranged on the end cap 111.

[0151] As shown in Figure 2 to Figure 4 In some embodiments of the present application, a manufacturing method of the battery cell 10 is provided, which includes:

[0152] S10: determining a target film according to the current type of the electrolyte of the battery cell 10, wherein the target film is not corroded when the target film is provided with the electrolyte of the current type.

[0153] Specifically, the coding area 16 of the battery cell 10 is arranged on the outer surface of the battery cell 10 by laser engraving or the like, and the coding area 16 includes but is not limited to a two-dimensional code, a numerical code, or an alphabetical code of the battery cell 10, etc., so as to identify the battery cell 10 through the coding area 16. The coding area 16 is arranged on the shell 11 of the battery cell 10, and specifically can be the shell body 112 or the end cap 111 of the shell 11, as shown in Figure 2 and Figure 3As shown, the coding area 16 is arranged on the end cover 111 of the shell 11.

[0154] During the process of electrolyte injection, the electrolyte remaining on the injection equipment is prone to drop on the battery monomer 10, and during the formation of the battery monomer 10, the electrolyte is prone to splash on the outer surface of the battery monomer 10 through the injection hole 13. The shell 11 of the battery monomer 10 is usually made of metal material, and the electrolyte is corrosive to the metal shell 11. When the electrolyte remains on the coding area 16, the electrolyte will corrode the coding area 16, so that the content of the coding area 16 cannot be recognized, thereby affecting the production of the battery monomer 10.

[0155] In this application, in order to reduce the corrosion of the electrolyte to the coding area 16 of the battery monomer 10, a protective film 15 is pasted on the coding area 16 of the battery monomer 10 during the manufacture of the battery monomer 10, so as to isolate the coding area 16 from the outside by the protective film 15, thereby reducing the corrosion of the electrolyte to the coding area 16.

[0156] It should be understood that the protective film 15 pasted on the coding area 16 of the battery monomer 10 needs to be able to resist the corrosion of the electrolyte, that is, the electrolyte cannot corrode the protective film 15, so as to form protection for the coding area 16 by the protective film 15, thereby reducing the corrosion of the electrolyte to the coding area 16.

[0157] Since there are many types of electrolyte for the battery monomer 10, and the corrosion ability of different electrolytes is different, it is necessary to select a corresponding protective film 15 according to the type of electrolyte, so that the protective film 15 can resist the corrosion of the electrolyte, thereby forming better protection for the coding area 16 of the battery monomer 10.

[0158] In the step of S10, the target film is determined according to the type of electrolyte of the battery monomer 10, and when the target film is provided with the electrolyte of the current type, the target film is not corroded, and the film material of the target film is the film material of the protective film 15.

[0159] In the step of S10, specifically comprising:

[0160] S11: Obtain the current type of electrolyte of the battery monomer 10.

[0161] Specifically, during the processing of the battery monomer 10, the type of electrolyte is set according to the application scene of the battery monomer 10, so as to make the protective film 15 have a good isolation effect on the electrolyte, it is necessary to know the type of electrolyte, so as to further select the material of the protective film 15 according to the type of electrolyte, so that the protective film 15 finally pasted on the coding area 16 can form better protection for the coding area 16.

[0162] S12: Prepare a plurality of sample films according to the current type of electrolyte, wherein at least the materials of the plurality of sample films are different.

[0163] Specifically, in the manufacturing process of the battery monomer 10, a plurality of sample films are prepared according to the type of electrolyte of the battery monomer 10, and the materials of any two sample films are different. For the type of electrolyte of the current battery monomer 10, a plurality of sample films with different materials are set to provide a plurality of samples for the selection of the protective film 15, so that the protective film 15 that meets the current electrolyte of the battery monomer 10 can be quickly obtained, thereby speeding up the production rhythm and effectively improving the production efficiency.

[0164] S13: Test the plurality of sample films, and determine a target film from the plurality of sample films according to the test data.

[0165] Specifically, the plurality of sample films are tested, the test data is recorded during the test, and the plurality of sample films are selected according to the test data, so as to select a sample film that meets the current electrolyte type from the plurality of sample films, and determine the sample film that meets the current electrolyte type as the target film.

[0166] Through steps S11 to S13, a plurality of sample films with different materials are prepared according to the current type of electrolyte of the battery monomer 10, and the plurality of sample films are tested, and the target film is determined according to the test data. In this way, the target film can be effectively adapted to the battery monomer 10, thereby reducing the corrosion of the coding area 16 after the electrolyte corrodes the protective film 15.

[0167] In some embodiments of the present application, in step S13, specifically further comprising:

[0168] S131: Corrosion test the plurality of sample films with the current type of electrolyte.

[0169] Specifically, when testing the plurality of sample films, the plurality of sample films are subjected to corrosion test. In the corrosion test, the electrolyte of the battery monomer 10 to be manufactured is used as the corrosion liquid, the corrosion liquid is dropped on the plurality of sample films respectively, and is maintained for a certain period of time (for example, 1 minute, 2 minutes, 3 minutes, 4 minutes, 5 minutes, 6 minutes, 7 minutes, 8 minutes, 9 minutes, etc.), and the corrosion data (such as corrosion depth) of the plurality of sample films is recorded, and the plurality of sample films are selected according to the corrosion data, so that the selected sample film can resist the corrosion of the electrolyte.

[0170] S132: Determine a preliminarily qualified sample film from the plurality of sample films according to the sample film not being corroded by the current type of electrolyte.

[0171] Specifically, in the corrosion test, the plurality of sample films are screened by the corrosion data, wherein, in order to make the protective film 15 have good corrosion resistance, the sample film not corroded by the electrolyte (for example, the sample film with a corrosion depth of 0) is screened out in the corrosion test, so as to take the sample film not corroded by the electrolyte as the preliminarily qualified sample film, thereby improving the resistance to the electrolyte.

[0172] S133: reviewing the preliminarily qualified sample film and determining the target film from the preliminarily qualified sample film according to the design requirements met by the review parameters, wherein the design requirements include at least one of the light transmittance, the thickness, the temperature resistance, the release force and the insulation.

[0173] Specifically, the plurality of sample films are screened by the corrosion test, thereby screening the preliminarily qualified sample film, in order to make the preliminarily qualified sample film more meet the use requirements of the battery monomer 10, the preliminarily qualified sample film is screened by the review, so as to further improve the quality of the protective film 15, and make the protective film 15 effectively meet the use requirements of the battery monomer 10.

[0174] In the process of testing the plurality of sample films, the sample film capable of resisting the electrolyte of the battery monomer 10 is directly screened by the corrosion test, the screened sample film is reviewed, and the sample film meeting the review is determined as the target film, so that the quality of the protective film 15 is effectively improved, and the protective film 15 can meet the use requirements of the current battery monomer 10.

[0175] In some embodiments of the present application, when the preliminarily qualified sample film is reviewed, the contents of the review include the light transmittance, the thickness, the temperature resistance, the release force and the insulation, that is, in step S133, specifically includes:

[0176] S1331: testing the light transmittance of the preliminarily qualified sample film, and determining the sample film with qualified light transmittance according to the light transmittance of the sample film being greater than or equal to a first threshold value.

[0177] Specifically, the light transmittance of the protective film 15 directly affects whether the coded area 16 can be effectively identified, the value of the light transmittance is a percentage, and the value range is 0-100%, the smaller the value, the worse the light transmission performance of the protective film 15 (at this time, the identification effect of the coded area 16 is poor), on the contrary, the larger the value, the better the light transmission performance of the protective film 15 (at this time, the identification effect of the coded area 16 is good), wherein the first threshold value is used to represent a preset value of the light transmittance of the protective film, which is a value in 0-100%.

[0178] The light transmittance of the sample film is rechecked at the rechecking time, so that the sample film screened has good light transmittance, so that the content of the coding area 16 of the battery monomer 10 can be effectively recognized through the protective film 15. In the rechecking process, the first threshold value is used as the critical value of screening, so that the convenience of screening is improved.

[0179] The first threshold value is greater than or equal to 50% and less than or equal to 100%. In this way, the protective film 15 can have good light transmittance, and the coding area 16 of the battery monomer 10 is reduced to shield, so as to realize effective identification of the coding area 16, thereby meeting the production requirements.

[0180] It should be pointed out that the first threshold value can be 50%, 60%, 70%, 80%, 90%, 100%.

[0181] In the present application, the value range of the first threshold value can be 70% to 100%. In this way, the protective film 15 can effectively reduce the manufacturing cost on the basis of having good light transmittance.

[0182] S1332: Test the thickness of the sample film that has passed the preliminary test, and determine the sample film with a qualified thickness according to the thickness of the sample film being less than or equal to a second threshold value.

[0183] Specifically, the thickness of the protective film 15 directly affects the corrosion resistance, structural strength and manufacturing cost of the protective film 15. In the present application, the unit of the thickness of the protective film 15 is millimeter. The greater the thickness of the protective film 15, the stronger the corrosion resistance and structural strength but the higher the manufacturing cost. The smaller the thickness of the protective film 15, the worse the corrosion resistance and structural strength but the lower the manufacturing cost. The second threshold value is used to represent the preset value of the thickness of the protective film 15, and the unit is micrometer.

[0184] The thickness of the sample film is rechecked at the rechecking time, so that the sample film screened has a suitable thickness, so as to reduce the manufacturing cost of the protective film 15, and also reduce the space occupied by the protective film 15. In the rechecking process, the second threshold value is used as the critical value of screening, so that the convenience of screening is improved.

[0185] The second threshold value is greater than 0 micrometers and less than or equal to 150 micrometers. In this way, the thickness of the protective film 15 can be effectively controlled on the basis of resisting electrolyte corrosion, thereby reducing the space occupied by the protective film 15 and the manufacturing cost of the protective film 15.

[0186] It should be pointed out that the second threshold value can be 1 micrometer, 10 micrometers, 20 micrometers, 30 micrometers, 40 micrometers, 50 micrometers, 60 micrometers, 100 micrometers, 150 micrometers.

[0187] In the present application, the second threshold value can be specifically in the range of 50 microns to 100 microns. In this way, the protective film 15 can effectively reduce the manufacturing cost while having good corrosion resistance and structural strength.

[0188] S1333: Test the temperature resistance of the preliminarily qualified sample film, and determine the sample film with qualified temperature resistance according to whether the temperature resistance of the sample film is greater than or equal to a third threshold value.

[0189] Specifically, the temperature resistance of the protective film 15 directly affects the temperature resistance of the protective film 15. In the present application, the temperature resistance of the protective film 15 is in units of degrees Celsius. The greater the temperature resistance of the protective film 15, the stronger the temperature resistance. The smaller the temperature resistance of the protective film 15, the worse the temperature resistance. The third threshold value is used to represent the preset value of the temperature resistance of the protective film 15, which is in units of degrees Celsius.

[0190] The temperature resistance of the sample film is reviewed during the review to make the screened sample film have appropriate temperature resistance, so that the protective film 15 has good temperature resistance to reduce the influence of temperature on the protective film 15. In the review process, the third threshold value is used as the critical value for screening, thereby improving the convenience of screening.

[0191] The third threshold value is greater than or equal to 300 degrees Celsius and less than or equal to 400 degrees Celsius. In this way, the protective film 15 can have the ability to resist high temperature to reduce the adverse effects of welding heat on the protective film 15 during welding of the battery monomer 10.

[0192] It should be pointed out that the third threshold value can be specifically 300 degrees Celsius, 310 degrees Celsius, 320 degrees Celsius, 330 degrees Celsius, 340 degrees Celsius, 350 degrees Celsius, 360 degrees Celsius, 370 degrees Celsius, 380 degrees Celsius, 390 degrees Celsius, or 400 degrees Celsius.

[0193] In the present application, the third threshold value can be specifically in the range of 350 degrees Celsius to 400 microns. In this way, the protective film 15 can effectively reduce the manufacturing cost while having good temperature resistance.

[0194] S1334: Test the temperature resistance of the preliminarily qualified sample film, and determine the sample film with qualified temperature resistance according to whether the temperature resistance of the sample film is greater than or equal to a third threshold value.

[0195] Specifically, the release force of the protective film 15 directly affects the fixing strength of the protective film 15. In the present application, the unit of the release force of the protective film 15 is Newton / 25 millimeters (i.e. the release force of the protective film 15 per 25 millimeters in the length direction of the protective film 15). The greater the release force of the protective film 15, the greater the fixing strength. The smaller the release force of the protective film 15, the worse the fixing strength. The fourth threshold value is used to represent the preset value of the release force of the protective film 15, and the unit is Newton / 25 millimeters.

[0196] The release force of the sample film is checked during the review, so that the screened sample film has a suitable release force, thereby enabling the protective film 15 to have sufficient strength after being pasted to reduce the situation of the protective film 15 falling off. In the review process, the fourth threshold value is used as the critical value for screening, thereby improving the convenience of screening.

[0197] The fourth threshold value is greater than or equal to 1 Newton / 25 millimeters and less than or equal to 10 Newton / 25 millimeters. In this way, the protective film 15 has good structural strength after being pasted, thereby reducing the situation of the protective film 15 falling off.

[0198] It should be noted that the fourth threshold value can be 1 Newton / 25 millimeters, 2 Newton / 25 millimeters, 3 Newton / 25 millimeters, 4 Newton / 25 millimeters, 5 Newton / 25 millimeters, 6 Newton / 25 millimeters, 7 Newton / 25 millimeters, 8 Newton / 25 millimeters, 9 Newton / 25 millimeters, or 10 Newton / 25 millimeters.

[0199] In the present application, the fourth threshold value can be 5 Newton / 25 millimeters to 10 Newton / 25 millimeters. In this way, the protective film 15 can effectively reduce the manufacturing cost while having fixing strength.

[0200] S1335: Test the insulation of the sample film that has passed the preliminary test, and determine the sample film with resistance that has passed the test according to the resistance value of the sample film being greater than or equal to the fifth threshold value.

[0201] Specifically, the resistance value of the protective film 15 directly affects the insulation performance of the protective film 15. In the present application, the unit of the resistance value of the protective film 15 is Ohm. The greater the resistance value of the protective film 15, the greater the insulation performance. The smaller the resistance value of the protective film 15, the worse the insulation performance. The fifth threshold value is used to represent the preset value of the resistance value of the protective film 15, and the unit is Ohm.

[0202] The insulation of the sample film is checked during the review, so that the screened sample film has a suitable insulation, thereby enabling the protective film 15 to have good insulation and reducing the situation of other components being short-circuited due to the conduction of the protective film 15. In the review process, the fifth threshold value is used as the critical value for screening, thereby improving the convenience of screening.

[0203] The fifth threshold value is greater than 10 to the power of 5 ohms and less than or equal to 10 to the power of 10 ohms. In this way, the protective film 15 has good insulation, and the risk of short circuiting other components due to the protective film 15 conducting electricity is reduced.

[0204] It should be noted that the fifth threshold value can be 10 to the power of 5 ohms, 10 to the power of 6 ohms, 10 to the power of 7 ohms, 10 to the power of 8 ohms, 10 to the power of 9 ohms, or 10 to the power of 10 ohms.

[0205] In this application, the fifth threshold value can be in the range of 10 to the power of 6 ohms to 10 to the power of 10 ohms. In this way, the protective film 15 can effectively reduce the manufacturing cost while maintaining good insulation.

[0206] Through steps S1331 to S1335, when the preliminary qualified sample film is reviewed, the light transmittance, thickness, temperature resistance, release force, and insulation of the preliminary qualified sample film are tested, so that the light transmittance, thickness, temperature resistance, release force, and insulation of the target film determined meet the use requirements of the battery monomer 10, and the protective film 15 can be effectively adapted to the battery monomer 10.

[0207] S20: Determine the processing parameters according to the structure parameters of the coded area 16 of the battery monomer 10.

[0208] Specifically, the coded area 16 is arranged on the outer surface of the battery monomer 10, and the protective film 15 is arranged on the outer surface of the battery monomer 10 by pasting and covers the entire coded area 16. Therefore, the structure parameters of the coded area 16 are the basis for processing the protective film 15.

[0209] The structure parameters of the coded area 16 are determined by measurement or the like, and the structure parameters include but are not limited to shape and size. The processing parameters are determined according to the structure parameters of the coded area 16, so that the protective film 15 processed can be more matched with the coded area 16, thereby effectively isolating the coded area 16 from the outside and reducing the corrosion of the electrolyte on the coded area 16.

[0210] Further, the structure parameters include the shape of the coded area 16 and the size of the coded area 16, and the processing parameters include the shape of the protective film 15 and the size of the protective film 15. The shape of the protective film 15 is consistent with the shape of the coded area 16, and the size of the protective film 15 is greater than or equal to the size of the coded area 16.

[0211] Such a configuration enables the protective film 15 to effectively adapt to the code area 16 , effectively protecting the code area 16 , and reducing the amount of the protective film 15 used, thereby reducing the manufacturing cost of the battery cell 10 .

[0212] Furthermore, the size of the protective film 15 is greater than or equal to the size of the coding area 16. When the protective film 15 is pasted on the outer surface of the battery cell 10, the entire coding area 16 is covered by the protective film 15, and the minimum distance between the edge of the coding area 16 and the edge of the protective film 15 is greater than or equal to 0 mm and less than or equal to 2 mm.

[0213] Such a configuration enables the protective film 15 to effectively adapt to the code area 16 , effectively protecting the code area 16 , and reducing the amount of the protective film 15 used, thereby reducing the manufacturing cost of the battery cell 10 .

[0214] It should be noted that the minimum distance between the edge of the engraved area 16 and the edge of the protective film 15 can be 0 mm, 0.5 mm, 0.8 mm, 1 mm, 1.2 mm, 1.5 mm, 1.8 mm, or 2 mm.

[0215] In the present application, the minimum distance between the edge of the engraved area 16 and the edge of the protective film 15 can specifically range from 0.8 mm to 1.2 mm. This setting allows the protective film 15 to effectively reduce the manufacturing cost while providing better protection for the engraved area 16.

[0216] like Figure 3 As shown, in Figure 3 In the embodiment, the code engraving area 16 is a rectangular structure, and the protective film 15 is also a rectangular structure. The size of the protective film 15 is larger than that of the code engraving area 16. Figure 3 In the figure, along the first direction (horizontal direction in the figure), the minimum distance between the edge of the protective film 15 and the edge of the code area 16 is a first distance a, and along the second direction (vertical direction in the figure), the minimum distance between the edge of the protective film 15 and the edge of the code area 16 is a second distance b. By setting the protective film 15, the protective film 15 can fully cover the code area 16, further reducing the situation where the electrolyte penetrates through the edge into the space between the protective film 15 and the code area 16, thereby corroding the code area 16.

[0217] S30: Processing the target film into a protective film 15 according to processing parameters.

[0218] Specifically, the target film is processed into the protective film 15 by cutting. This arrangement facilitates processing of the target film, effectively improves processing efficiency, and speeds up production tact.

[0219] S40: The protective film 15 is adhered to the outer surface of the battery monomer 10, so that the coding area 16 is covered by the protective film 15.

[0220] Specifically, after the protective film 15 is processed, the protective film 15 is connected with the outer surface of the battery monomer 10 by adhesion, so as to cover the coding area 16 of the battery monomer 10 by the protective film 15, thereby isolating the coding area 16 from the outside by the protective film 15, reducing the adverse effects of electrolyte and the like on the coding area 16, and further meeting the production requirements.

[0221] The protective film 15 is adhered to the outer surface of the battery monomer 10, so that the coding area 16 is covered by the protective film 15.

[0222] In some embodiments of the present application, in step S40, specifically comprising:

[0223] S41: Receiving and fixing the battery monomer 10.

[0224] Specifically, when the protective film 15 is pasted on the coding area 16 of the battery monomer 10, the battery monomer 10 is first arranged on the corresponding clamp, and the battery monomer 10 is fixed by the clamp to maintain the position of the battery monomer 10, so as to facilitate the positioning during the process of pasting the protective film 15 on the battery monomer 10, and further improve the accuracy of pasting the protective film 15.

[0225] S42: Obtaining the current state of the outer surface of the battery monomer 10 with the coding area 16.

[0226] Specifically, before pasting the protective film 15 on the battery monomer 10, the current state of the outer surface of the battery monomer 10 which needs to be pasted with the protective film 15 is obtained, so as to eliminate the factors affecting the pasting of the protective film 15, such as residual electrolyte, dust or other foreign matters at the pasting position.

[0227] When there are foreign matters at the position of the battery monomer 10 where the protective film 15 is pasted, the foreign matters need to be removed before pasting the protective film 15, so as to improve the adhesion of the protective film 15 and the battery monomer 10, and further improve the pasting effect of the protective film 15.

[0228] S43: According to the fact that no electrolyte is left on the outer surface of the battery monomer 10 with the coding area 16, the protective film 15 is pasted on the outer surface of the battery monomer 10, so that all the coding areas 16 are covered by the protective film 15.

[0229] Specifically, the protective film 15 is pasted on the battery cell 10 and covers all the coding areas 16, and the purpose is to isolate the coding areas 16 from the electrolyte. When the protective film 15 is not pasted, if the coding areas 16 remain electrolyte, it will cause corrosion to the coding areas 16, therefore, it is necessary to discharge the electrolyte remaining in the coding areas 16, that is, before pasting the protective film 15, it is necessary to keep the coding areas 16 without residual electrolyte, so as to reduce the corrosion of the electrolyte to the coding areas 16.

[0230] Through steps S41 to S43, when the protective film 15 is pasted on the battery cell 10, the battery cell 10 is first fixed, then the surface of the battery cell 10 with the coding area 16 is detected whether there is residual electrolyte, and the protective film 15 is pasted on the battery cell 10 after determining that there is no residual electrolyte, thereby reducing the case that the electrolyte remains between the protective film 15 and the battery cell 10.

[0231] In some embodiments of the present application, in step S43, specifically further comprising:

[0232] S431: Obtain the current position of the coding area 16.

[0233] Specifically, after the battery cell 10 is fixed, the outer surface of the battery cell 10 with the coding area 16 is pasted with the protective film 15, therefore, the current position of the coding area 16 needs to be known, so that the protective film 15 can accurately paste the protective film 15 on the outer surface of the battery cell 10 with the coding area 16 and completely cover the coding area 16.

[0234] S432: Control the protective film 15 to be arranged above the coding area 16.

[0235] Specifically, in the process of bonding the protective film 15, the position of the coding area 16 of the battery cell 10 is moved, and the interval is arranged above the coding area 16, so that the protective film 15 is opposite to the coding area 16, so as to paste the protective film 15 on the battery cell 10 by vertically moving the protective film 15 and cover all the protective film 15.

[0236] S433: Control the protective film 15 to rotate around a preset rotation axis to adjust the angle of the protective film 15, wherein the preset rotation axis is perpendicular to the plane where the coding area 16 is located. By rotating the protective film 15, the angle of the protective film 15 relative to the coding area 16 is controlled within a reasonable range (the relative angle between the protective film 15 and the coding area 16 is 0 degree or close to 0 degree), thereby improving the pasting accuracy of the protective film 15.

[0237] S434: Control the translation of the protective film 15 to enable the projection of the protective film 15 on the battery monomer 10 to cover all the coded areas 16, wherein the translation direction of the protective film 15 is parallel to the coded areas 16. By translating the protective film 15, the position of the protective film 15 relative to the coded areas 16 is controlled within a reasonable range, reducing the exposure of the coded areas 16 outside the protective film 15, thereby improving the sticking accuracy of the protective film 15.

[0238] S435: Control the protective film 15 to be pasted on the outer surface of the battery monomer 10 to cover all the coded areas 16.

[0239] Specifically, during the pasting process of the protective film 15, the protective film 15 is lowered until the protective film 15 is pasted on the outer surface of the battery monomer 10 and completely covers the coded areas 16.

[0240] It should be understood that the protective film 15 is pasted and fixed with the outer surface of the battery monomer 10, wherein the protective film 15 can have a self-adhesive layer, or an adhesive layer can be coated on the outer surface of the battery monomer 10.

[0241] By steps S41 to S43, by controlling the angle and position of the protective film 15, the sticking accuracy of the protective film 15 can be effectively improved, so that the protective film 15 can effectively protect the coded areas 16, further reducing the corrosion problem of the coded areas 16 caused by the electrolyte.

[0242] In some embodiments of the present application, in step S43, specifically further comprising:

[0243] S436: Control the protective film 15 to be pasted on the outer surface of the battery monomer 10.

[0244] Specifically, during the pasting process of the protective film 15, the protective film 15 is lowered until the protective film 15 is pasted on the outer surface of the battery monomer 10 and completely covers the coded areas 16.

[0245] S437: Apply a preset pressure on the side of the protective film 15 away from the battery monomer 10.

[0246] Specifically, the preset pressure refers to the pressure applied on the side of the protective film 15 away from the battery monomer 10, which is a set value with the unit of Newton.

[0247] When the protective film 15 is pasted with the outer surface of the battery monomer 10, by applying pressure to the protective film 15, the protective film 15 can be tightly contacted with the outer surface of the battery monomer 10, thereby improving the strength of the adhesion, so that the stability of the protective film 15 after pasting can be improved.

[0248] In some embodiments of the present application, the pressure generated by the preset pressure on the protective film 15 is in the range of 0.4 MPa to 0.6 MPa.

[0249] Specifically, during the process of adhering the protective film 15, by setting the pressure generated by the preset pressure on the protective film 15 in the range of 0.4 MPa to 0.6 MPa, the battery monomer 10 can be prevented from being deformed by extrusion on the basis of ensuring that the protective film 15 has sufficient adhesive strength during the process of adhering the protective film 15.

[0250] It should be noted that the pressure generated by the preset pressure on the protective film 15 can be 0.4 MPa, 0.45 MPa, 0.5 MPa, 0.55 MPa, or 0.6 MPa.

[0251] S438: According to the preset time length of the pressure applied to the protective film 15, the preset pressure on the protective film 15 is removed.

[0252] Specifically, the preset time length refers to the time length during which the pressure is applied to the side of the protective film 15 away from the battery monomer 10 and maintained on the protective film 15, and the unit is second.

[0253] By setting the pressure application time length of the protective film 15, the protective film 15 and the battery monomer 10 can have good adhesive strength during the process of adhering the protective film 15, thereby improving the adhesive effect of the battery monomer 10.

[0254] In some embodiments of the present application, the preset time length is in the range of 5 seconds to 25 seconds. Specifically, by setting the preset time length in the range of 5 seconds to 25 seconds, the protective film 15 and the battery monomer 10 can have good adhesive strength during the process of adhering the protective film 15, thereby further improving the adhesive effect of the battery monomer 10.

[0255] It should be noted that the preset time length can be 5 seconds, 7 seconds, 9 seconds, 10 seconds, 13 seconds, 15 seconds, 17 seconds, 20 seconds, 22 seconds, 24 seconds, or 25 seconds.

[0256] By steps S436 to S438, during the process of adhering the protective film 15, the preset pressure and the preset time length are set, so that the protective film 15 can be adhered under the action of the adhesive pressure, thereby improving the adhesive strength of the protective film 15 and further reducing the situation of the protective film 15 falling off.

[0257] In the present application, according to the current type of electrolyte of the processed battery monomer 10, a target film that is compatible with the electrolyte is selected, that is, the target film cannot be corroded by the electrolyte, and the target film is processed into the protective film 15 required by the battery monomer 10, and then the processed protective film 15 is pasted to the outer surface of the battery monomer 10 and covers the coding area 16, so that the coding area 16 is isolated from the outside world. When the electrolyte splashes, the electrolyte cannot fall on the coding area 16 because the protective film 15 shields the coding area 16, thereby effectively reducing the occurrence of electrolyte corrosion of the coding area 16, so that the coding area 16 can be effectively identified, thereby effectively improving the qualified rate of the battery monomer 10.

[0258] For example, taking the most widely used organic electrolyte with LiPF6 as the solute in the current power battery manufacturing as an example, the solvent is mostly an ester compound, which has less risk of corroding the aluminum shell. The main corrosion risk is the hydrogen fluoride (HF) generated by the reaction of LiPF6 with water. For hydrogen fluoride corrosion, a polyimide (PI) adhesive tape with high corrosion resistance can be selected. Polyimide is one of the best organic polymer materials in terms of comprehensive performance, and has excellent properties such as high temperature resistance (400 degrees Celsius), high insulation, acid and alkali corrosion resistance, and high light transmittance (more than 90%), which can well meet the needs of the coding area 16 protective film 15.

[0259] In the production process of the battery monomer 10, the above-mentioned battery monomer 10 manufacturing method is implemented by a battery production line.

[0260] The second aspect of the present application proposes an end cover assembly, which comprises an end cover 111 and a protective film 15. The outer surface of the end cover 111 is provided with a coding area 16, and the protective film 15 is as described above. The protective film 15 is pasted to the outer surface of the end cover 111 and covers the coding area 16.

[0261] Specifically, in the processing of the battery monomer 10, according to the current type of electrolyte of the processed battery monomer 10, a target film that is compatible with the electrolyte is selected, that is, the target film cannot be corroded by the electrolyte, and the target film is processed into the protective film 15 required by the battery monomer 10, and then the processed protective film 15 is pasted to the outer surface of the battery monomer 10 and covers the coding area 16, so that the coding area 16 is isolated from the outside world. When the electrolyte splashes, the electrolyte cannot fall on the coding area 16 because the protective film 15 shields the coding area 16, thereby effectively reducing the occurrence of electrolyte corrosion of the coding area 16, so that the coding area 16 can be effectively identified, thereby effectively improving the qualified rate of the battery monomer 10.

[0262] The third aspect of the present application proposes a battery monomer 10 manufactured by the above-mentioned battery production line.

[0263] Specifically, when the battery cell 10 is processed, according to the current type of the electrolyte of the processed battery cell 10, a target film that is adapted to the electrolyte is selected, that is, the target film cannot be corroded by the electrolyte, and the target film is processed into the protective film 15 required by the battery cell 10, and then the processed protective film 15 is pasted to the outer surface of the battery cell 10 and covers the coding area 16, so that the coding area 16 is isolated from the outside world. When the electrolyte splashes, the electrolyte cannot fall on the coding area 16 due to the shielding of the protective film 15 to the coding area 16, thereby effectively reducing the occurrence of the electrolyte corroding the coding area 16, so that the coding area 16 can be effectively identified, thereby effectively meeting the requirement of improving the qualified rate of the battery cell 10.

[0264] The fourth aspect of the present application provides a battery device 100, which comprises the battery cell 10 as above.

[0265] Specifically, when the battery cell 10 is processed, according to the current type of the electrolyte of the processed battery cell 10, a target film that is adapted to the electrolyte is selected, that is, the target film cannot be corroded by the electrolyte, and the target film is processed into the protective film 15 required by the battery cell 10, and then the processed protective film 15 is pasted to the outer surface of the battery cell 10 and covers the coding area 16, so that the coding area 16 is isolated from the outside world. When the electrolyte splashes, the electrolyte cannot fall on the coding area 16 due to the shielding of the protective film 15 to the coding area 16, thereby effectively reducing the occurrence of the electrolyte corroding the coding area 16, so that the coding area 16 can be effectively identified, thereby effectively meeting the requirement of improving the qualified rate of the battery cell 10.

[0266] The above description is only a summary of the technical solutions of the present application. In order to more clearly understand the technical means of the present application, the specific embodiments of the present application can be implemented in accordance with the content of the description, and in order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the following specific embodiments of the present application are described.

[0267] In the embodiments of the present application, as shown in Figure 2 to Figure 4 The present application provides a manufacturing method of a battery cell 10, which comprises:

[0268] S10: determining a target film according to the current type of the electrolyte of the battery cell 10, wherein when the target film is provided with the electrolyte of the current type, the target film is not corroded.

[0269] In the step of S10, the current type of the electrolyte of the battery cell 10 is obtained, a plurality of sample films are prepared according to the electrolyte of the current type, wherein at least the materials of the plurality of sample films are different, the plurality of sample films are tested, and the target film is determined from the plurality of sample films according to the test data.

[0270] Furthermore, the step of testing a plurality of film samples and determining a target film among the plurality of film samples based on the test data includes performing corrosion tests on the plurality of film samples using a current type of electrolyte, determining preliminarily qualified film samples among the plurality of film samples based on the fact that the film samples are not corroded by the current type of electrolyte, reviewing the preliminarily qualified film samples and satisfying design requirements based on review parameters, and determining a target film among the preliminarily qualified film samples, wherein the design requirements include at least one of transmittance, thickness, temperature resistance, release force and insulation.

[0271] Furthermore, in reviewing the preliminarily qualified sample film and satisfying the design requirements based on the review parameters, the step of determining the target film from the preliminarily qualified sample film includes testing the transmittance of the preliminarily qualified sample film, and determining the sample film with qualified transmittance based on the transmittance of the sample film being greater than or equal to a first threshold value, testing the thickness of the preliminarily qualified sample film, and determining the sample film with qualified thickness based on the thickness of the sample film being less than or equal to a second threshold value, testing the temperature resistance of the preliminarily qualified sample film, and determining the sample film with qualified temperature resistance based on the temperature tolerance of the sample film being greater than or equal to a third threshold value, testing the release force of the preliminarily qualified sample film, and determining the sample film with qualified release force based on the release force of the sample film being greater than or equal to a fourth threshold value, testing the insulation of the preliminarily qualified sample film, and determining the sample film with qualified resistance based on the resistance value of the sample film being greater than or equal to a fifth threshold value.

[0272] The first threshold is greater than or equal to 70% and less than or equal to 100%. The second threshold is greater than 50 microns and less than or equal to 100 microns. The third threshold is greater than or equal to 350 degrees Celsius and less than or equal to 400 degrees Celsius. The fourth threshold is greater than or equal to 5 Newtons per 25 millimeters and less than or equal to 10 Newtons per 25 millimeters. The fifth threshold is greater than 10 to the power of 6 ohms and less than or equal to 10 to the power of 10 ohms.

[0273] S20 : ​​Determine processing parameters according to the structural parameters of the code area 16 of the battery cell 10 .

[0274] Step S20 includes determining processing parameters based on the structural parameters of the code area 16 of the battery cell 10. The structural parameters include the shape and size of the code area 16. The processing parameters include the shape and size of the protective film 15. The shape of the protective film 15 is consistent with the shape of the code area 16, and the size of the protective film 15 is greater than or equal to the size of the code area 16. The size of the protective film 15 is greater than or equal to the size of the code area 16. When the protective film 15 is attached to the outer surface of the battery cell 10, the entire code area 16 is covered by the protective film 15, and the minimum distance between the edge of the code area 16 and the edge of the protective film 15 is greater than or equal to 0.8 mm and less than or equal to 1.2 mm.

[0275] S30: Process the target film into the protective film 15 according to the processing parameter. The target film is processed into the protective film 15 by cutting.

[0276] S40: Bond the protective film 15 to the outer surface of the battery cell 10 so that the coding area 16 is covered by the protective film 15.

[0277] The step of S40 includes receiving and fixing the battery cell 10, obtaining the current state of the outer surface of the battery cell 10 with the coding area 16, and controlling the protective film 15 to be bonded to the outer surface of the battery cell 10 so that all the coding area 16 is covered by the protective film 15 according to that no electrolyte remains on the outer surface of the battery cell 10 with the coding area 16.

[0278] Further, the step of controlling the protective film 15 to be bonded to the outer surface of the battery cell 10 so that all the coding area 16 is covered by the protective film 15 according to that no electrolyte remains on the outer surface of the battery cell 10 with the coding area 16 includes obtaining the current position of the coding area 16, controlling the protective film 15 to be above the coding area 16, controlling the protective film 15 to rotate around a preset rotation axis to adjust the angle of the protective film 15, wherein the preset rotation axis is perpendicular to the plane where the coding area 16 is located, controlling the protective film 15 to translate so that the projection of the protective film 15 on the battery cell 10 can cover all the coding area 16, wherein the translation direction of the protective film 15 is parallel to the coding area 16, and controlling the protective film 15 to be bonded to the outer surface of the battery cell 10 to cover all the coding area 16.

[0279] Further, the step of controlling the protective film 15 to be bonded to the outer surface of the battery cell 10 to cover all the coding area 16 includes controlling the protective film 15 to be bonded to the outer surface of the battery cell 10, applying a preset pressure on the side of the protective film 15 away from the battery cell 10, and releasing the preset pressure on the protective film 15 according to that the pressure application time of the protective film 15 reaches a preset time.

[0280] The preset pressure generates a pressure in the range of 0.4 MPa to 0.6 MPa on the protective film 15. The preset time is in the range of 5 seconds to 25 seconds.

[0281] Specifically, according to the current type of the electrolyte of the processed battery monomer 10, a target film that is compatible with the electrolyte is selected, i.e., the target film cannot be corroded by the electrolyte, and the target film is processed into the protective film 15 required by the battery monomer 10, and then the processed protective film 15 is pasted to the outer surface of the battery monomer 10 and covers the coding area 16, so that the coding area 16 is isolated from the outside world. When the electrolyte splashes, the electrolyte cannot fall on the coding area 16 because the protective film 15 shields the coding area 16, thereby effectively reducing the occurrence of electrolyte corrosion of the coding area 16, so that the coding area 16 can be effectively identified, thereby effectively improving the qualified rate of the battery monomer 10.

[0282] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement to part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application, and they should be covered in the scope of the claims and the specification of the present application. In particular, as long as there is no structural conflict, the technical features mentioned in each embodiment can be combined in any way. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A method for manufacturing a battery cell, characterized in that: The manufacturing method of the battery cell includes: Determining a target film according to a current type of an electrolyte in a battery cell, comprising: obtaining a current type of an electrolyte in the battery cell, preparing a plurality of sample films according to the current type of electrolyte, wherein at least the plurality of sample films are made of different materials, testing the plurality of sample films, and determining the target film from the plurality of sample films according to the test data, wherein the target film is not corroded when the current type of electrolyte is applied to the target film; Determining processing parameters according to structural parameters of the coding area of ​​the battery cell; processing the target film into a protective film according to the processing parameters; The protective film is adhered to the outer surface of the battery cell so that the code area is covered by the protective film.

2. The method for manufacturing a battery cell according to claim 1, wherein: The testing of the plurality of sample films and determining the target film from the plurality of sample films according to the test data includes: performing a corrosion test on the plurality of sample films using the current type of electrolyte; Determining a preliminarily qualified sample film from the plurality of sample films based on the sample film not being corroded by the current type of electrolyte; The preliminarily qualified sample films are reviewed and the design requirements are met according to the review parameters, and the target film is determined from the preliminarily qualified sample films, wherein the design requirements include at least one of transmittance, thickness, temperature resistance, release force and insulation.

3. The method for manufacturing a battery cell according to claim 2, wherein: The review of the preliminarily qualified sample films and the determination of whether the preliminarily qualified sample films meet the design requirements according to the review parameters, and the determination of the target film from the preliminarily qualified sample films, comprises: Testing the transmittance of the preliminarily qualified sample film, and determining the sample film as having qualified transmittance based on the transmittance of the sample film being greater than or equal to a first threshold; Testing the thickness of the preliminarily qualified sample film, and determining the sample film as having qualified thickness based on the thickness of the sample film being less than or equal to a second threshold; Testing the temperature resistance of the preliminarily qualified sample film, and determining the sample film as qualified in terms of temperature resistance based on the temperature resistance of the sample film being greater than or equal to a third threshold; Testing the release force of the preliminarily qualified sample film, and determining the sample film as having qualified release force according to the release force of the sample film being greater than or equal to a fourth threshold; The insulation property of the preliminarily qualified sample film is tested, and the sample film is determined to have qualified resistance according to the resistance value of the sample film being greater than or equal to a fifth threshold.

4. The method for manufacturing a battery cell according to claim 3, wherein: The first threshold is greater than or equal to 50% and less than or equal to 100%; And / or, the second threshold is greater than 0 micrometers and less than or equal to 150 micrometers; And / or, the third threshold is greater than or equal to 300 degrees Celsius and less than or equal to 400 degrees Celsius; And / or, the fourth threshold is greater than or equal to 1 N / 25 mm and less than or equal to 10 N / 25 mm; And / or, the fifth threshold is greater than 10 to the power of 5 ohms and less than or equal to 10 to the power of 10 ohms.

5. The method for manufacturing a battery cell according to claim 1, wherein: In the step of determining processing parameters based on the structural parameters of the coding area of ​​the battery cell, the structural parameters include the shape of the coding area and the size of the coding area, and the processing parameters include the shape of the protective film and the size of the protective film, wherein the shape of the protective film is consistent with the shape of the coding area, and the size of the protective film is greater than or equal to the size of the coding area.

6. The method for manufacturing a battery cell according to claim 5, wherein: When the protective film is attached to the outer surface of the battery cell, the entire code area is covered by the protective film, and the minimum distance between the edge of the code area and the edge of the protective film is greater than or equal to 0 mm and less than or equal to 2 mm.

7. The method for manufacturing a battery cell according to claim 1, wherein: In the step of processing the target film into a protective film according to the processing parameters, the target film is processed into the protective film by cutting.

8. The method for manufacturing a battery cell according to any one of claims 1 to 7, wherein: The step of bonding the protective film to the outer surface of the battery cell so that the code area is covered by the protective film includes: receiving and fixing the battery cell; Acquiring a current state of the outer surface of the battery cell having the engraved area; According to the fact that no electrolyte remains on the outer surface of the battery cell having the code area, the protective film is controlled to be attached to the outer surface of the battery cell so that the entire code area is covered by the protective film.

9. The method for manufacturing a battery cell according to claim 8, wherein: According to the fact that no electrolyte remains on the outer surface of the battery cell having the code area, controlling the protective film to be attached to the outer surface of the battery cell so that the entire code area is covered by the protective film includes: Obtaining the current position of the engraved area; Controlling the protective film to be disposed above the code engraving area; Controlling the protective film to rotate about a preset rotation axis to adjust the angle of the protective film, wherein the preset rotation axis is perpendicular to the plane where the code area is located; Controlling the translation of the protective film so that the projection of the protective film on the battery cell can cover the entire code area, wherein the translation direction of the protective film is parallel to the code area; The protective film is controlled to be attached to the outer surface of the battery cell to cover the entire code area.

10. The method for manufacturing a battery cell according to claim 9, wherein: The step of controlling the protective film to be attached to the outer surface of the battery cell to cover the entire coding area includes: Controlling the protective film to be attached to the outer surface of the battery cell; Applying a preset pressure on a side of the protective film facing away from the battery cell; According to the duration of the pressure applied to the protective film reaching a preset duration, the preset pressure on the protective film is released.

11. The method for manufacturing a battery cell according to claim 10, wherein: The pressure exerted by the preset pressure on the protective film is in the range of 0.4 MPa to 0.6 MPa; And / or, the preset duration is in the range of 5 seconds to 25 seconds.

12. An end cap assembly, characterized in that: The end cap assembly comprises: An end cap, wherein the outer surface of the end cap is provided with a code area; A protective film, wherein the protective film is the protective film according to any one of claims 1 to 11, and the protective film is adhered to the outer surface of the end cap and covers the engraved area.

13. A battery cell, characterized in that: The battery cell includes the end cap assembly of claim 12 .

14. A battery device, characterized in that: The battery device includes the battery cell according to claim 13 .

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