Battery cell, battery device, power consuming device, and overhang size detection method

Abstract

The application provides a battery monomer, a battery device, a power consumption device and an overhang size detection method, and belongs to the technical field of batteries. The battery monomer comprises a positive electrode sheet, a negative electrode sheet and a diaphragm between the positive electrode sheet and the negative electrode sheet; the positive electrode sheet comprises a first body and a first tab provided at a first end of the first body in a first direction, and an insulating part is arranged at a position close to the first tab of the first body; the insulating part protrudes from the first end of the first body and the first end of the diaphragm in the first direction; and the optical characteristics of the insulating part are different from the optical characteristics of the diaphragm, so that the first imaging of the insulating part in a detection camera is different from the second imaging of the diaphragm in the detection camera. The insulating part can block the remaining diaphragms in the field of view of the detection camera except the diaphragm of the current layer, so that the diaphragm area recognized by the detection camera is the diaphragm of the current layer, and the accuracy of the detection result is improved.

Description

Technical Field

[0001] This application relates to the field of battery technology, and in particular to a battery cell, battery device, power device, and overhang dimension detection method. Background Technology

[0002] Energy conservation and emission reduction are key to sustainable social development, and electric vehicles, due to their energy-saving and environmentally friendly advantages, have become an important component of the automotive industry's sustainable development. For electric vehicles, battery technology is a crucial factor in their development.

[0003] In related technologies, during the processing of wound battery cells, in order to ensure that the positive and negative electrode plates of the battery do not come into direct contact, the separator usually needs to extend beyond the negative electrode plate by a certain size. However, how to improve the accuracy of size detection has always been a problem worthy of attention in the industry. Summary of the Invention

[0004] This application aims to at least address one of the technical problems existing in the background art. Therefore, one objective of this application is to provide a battery cell, battery device, power-consuming device, and overhang dimension detection method to improve the low overhang dimension detection accuracy of separators and negative electrode sheets in related technologies.

[0005] An embodiment of the first aspect of this application provides a battery cell, including: a positive electrode, a negative electrode, and a separator located between the positive electrode and the negative electrode; the positive electrode includes a first body and a first tab disposed at a first end of the first body along a first direction, and an insulating portion is disposed on the first body near the first tab, the insulating portion protruding from the first end of the first body and the first end of the separator along the first direction; the optical characteristics of the insulating portion are different from the optical characteristics of the separator, so that the first image of the insulating portion in the detection camera is different from the second image of the separator in the detection camera.

[0006] In the technical solution of this application embodiment, the insulating part can block all membranes except the current layer membrane in the field of view of the detection camera, so that the membrane area identified by the detection camera is the current layer membrane, thereby accurately measuring the overhang dimension between the membrane and the negative electrode sheet, improving the accuracy of the detection results. Moreover, compared with the infrared projection detection method in related technologies, it does not need to penetrate multiple layers, eliminating the possibility of missed detections and false negatives, resulting in more accurate detection results.

[0007] In some embodiments, the first body has a first surface and a second surface disposed opposite to each other along a second direction, and an insulating portion is disposed on the first surface or the second surface; wherein the first direction is perpendicular to the second direction.

[0008] By placing the insulating portion on either the first or second surface of the first body, the membrane of the layers other than the current layer can be blocked during the winding process, thereby accurately detecting the boundary of the current layer's membrane and improving the accuracy of the overhang dimension detection between the membrane and the negative electrode.

[0009] In some embodiments, the first body has a first surface and a second surface disposed opposite to each other along a second direction, and both the first surface and the second surface are provided with insulating portions, wherein the first direction is perpendicular to the second direction.

[0010] By providing insulating portions on both the first and second surfaces of the first body, the insulating portions can shield the membranes of the remaining layers except the current layer during the winding process, thereby accurately detecting the boundary of the current layer's membrane and improving the accuracy of the overhang dimension detection between the membrane and the negative electrode.

[0011] In some embodiments, the insulating portion disposed on the first surface has a first protrusion protruding from the first surface, and the insulating portion disposed on the second surface has a second protrusion protruding from the second surface, and the first protrusion and the second protrusion are connected.

[0012] It is understandable that during the die-cutting process, the edge of the first body may have burrs. By connecting the first protrusion and the second protrusion, the first end of the first body can be covered, thereby covering the burrs and improving the problem of low voltage or safety caused by burrs easily tearing or scratching the diaphragm.

[0013] In some embodiments, the first body includes a first current collector and a first active layer disposed on the surface of the first current collector. The first current collector has an empty foil area protruding from the first active layer. A first electrode is disposed at a first end of the empty foil area along a first direction. An insulating portion covers the empty foil area and also covers a portion of the first active layer.

[0014] By setting an insulating layer in the empty foil area and extending the insulating layer to the first active layer covering the area, the insulating layer can completely cover the empty foil area, avoiding the risk of the empty foil area being exposed.

[0015] In some embodiments, the width H1 of the empty foil area along the first direction satisfies: 1.5mm ≤ H1 ≤ 3.5mm.

[0016] In this embodiment, by setting the width H1 of the empty foil area to be greater than or equal to 1.5 mm, the phenomenon of coating overflow during the application of positive electrode active material can be avoided. By setting H1 to be less than or equal to 3.5 mm, the area of ​​positive electrode active material on the positive electrode sheet can be increased, thereby increasing the energy density of the battery cell.

[0017] In some embodiments, the width H2 of the portion of the insulating part covering the first active layer along the first direction satisfies: 0.1mm ≤ H2 ≤ 2mm.

[0018] By setting the width of the portion of the insulating part covering the first active layer to be greater than or equal to 0.1 mm, the empty foil area can be completely covered, improving the risk of easy exposure of the empty foil area. By setting H2 to less than or equal to 2 mm, the area of ​​effective positive electrode active material on the positive electrode sheet can be increased, thereby increasing the energy density of the battery cell.

[0019] In some embodiments, the width H3 of the insulating portion along the first direction satisfies: 4.5mm ≤ H3 ≤ 12mm.

[0020] By setting the width H3 of the insulating part to be greater than or equal to 4.5 mm, the insulating part can protrude from the separator. This allows the insulating part to completely cover the separator layers other than the current layer in the inspection image from the inspection camera, thereby improving the accuracy of the overhang dimension detection between the separator and the negative electrode. Simultaneously, by setting the width of the insulating part to be less than or equal to 12 mm, excessive volume is avoided, increasing the battery's energy density. Furthermore, excessive height of the insulating part prevents it from interfering with the connection between the first tab and the electrode terminal.

[0021] In some embodiments, the insulating portion includes an adhesive layer and an insulating layer, one side of the adhesive layer is bonded to the insulating layer, and the other side of the adhesive layer is bonded to the first body.

[0022] By setting an adhesive layer and an insulating layer, the processing of the insulating part and its connection with the first body can be simplified, improving processing and assembly efficiency, while reducing costs.

[0023] In some embodiments, the insulating layer is composed of at least one of polyethylene terephthalate, polypropylene, polyethylene, and polypropylene block copolymers.

[0024] The insulating layer made of the above materials can maintain electrochemical stability in the electrolyte, thereby achieving insulation, and the materials are low in cost.

[0025] In some embodiments, the adhesive layer comprises at least one of polyolefin, polyester, and styrene-isobutylene copolymer.

[0026] The adhesive layer made of the above materials can achieve the connection between the insulating layer and the first body, with high connection reliability and low material cost.

[0027] In some embodiments, the light transmittance A of the insulating portion satisfies: 65% ≤ A ≤ 80%.

[0028] By setting the light transmittance to be greater than or equal to 65%, the diaphragm 120 and the insulating part 140 can be distinguished. At the same time, by setting the light transmittance to be less than or equal to 80%, the diaphragm can be effectively blocked within the field of view of the detection camera.

[0029] In some embodiments, the haze B of the insulation portion satisfies: 60% ≤ B ≤ 100%.

[0030] By setting the haze level to be greater than or equal to 60% and less than or equal to 100%, the insulating part can be in a high haze condition, which can effectively block the diaphragm within the field of view of the detection camera. At the same time, it can be distinguished from the diaphragm in the field of view of the camera, which helps to improve the accuracy of detection.

[0031] In some embodiments, the thickness H4 of the insulating portion along a second direction perpendicular to the first direction satisfies: 9μm≤H4≤30μm.

[0032] By setting the thickness of the insulating part to be greater than or equal to 9μm, its puncture strength can be improved, and it can be prevented from being punctured or scratched by burrs. In addition, by setting the thickness of the insulating part to be less than or equal to 30μm, it can be prevented that the insulating part protrudes too much from the first body in the second direction, reducing the risk of edge bulging due to poor size control, and improving the energy density of the battery cell.

[0033] In some embodiments, when the insulation portion is immersed in the electrolyte for 1000 hours, the peel strength C of the insulation portion satisfies: 15 N / m ≤ C ≤ 20 N / m.

[0034] By setting the peel strength of the insulation part to be greater than or equal to 15 N / m, the reliability of the connection between the insulation part and the first body can be improved. By setting the peel strength of the insulation part to be less than or equal to 20 N / m, the insulation part and the first body can be easily separated when needed, thereby balancing the reliability and detachability of the connection.

[0035] In some embodiments, the puncture strength D of the insulation portion satisfies: D≥400gf.

[0036] By setting the puncture strength of the insulation part to be greater than or equal to 400gf, it is possible to prevent the insulation part from being punctured by the burrs on the edge of the first body, thereby improving the reliability of the battery cell.

[0037] In some embodiments, the insulating portion has electrochemical stability when the voltage U satisfies 2.5V≤U≤4.5V.

[0038] When the voltage U satisfies 2.5V≤U≤4.5V, the insulation part will not undergo oxidation-reduction reaction, which can keep the insulation part stable during the operation of the battery cell and improve the reliability of the battery cell.

[0039] An embodiment of the second aspect of this application provides a battery device that includes the battery cell described in the above embodiments.

[0040] An embodiment of the third aspect of this application provides an electrical device that includes the battery device described in the above embodiments, the battery device being used to provide electrical energy.

[0041] An embodiment of the fourth aspect of this application provides an energy storage device, which includes the battery device in the above embodiments, and the energy storage device is used to store electrical energy.

[0042] An embodiment of the fifth aspect of this application provides an overhang size detection method, the method comprising: acquiring a detection image of a region to be detected using a detection camera, wherein the region to be detected includes a positive electrode sheet, a separator, and a negative electrode sheet arranged in sequence, the positive electrode sheet, the negative electrode sheet, and the separator being wound or stacked to form a battery cell in any of the above embodiments, the detection camera being located on the side of the negative electrode sheet away from the separator, and the detection image capturing the insulating portion of the negative electrode sheet, the separator, and the positive electrode sheet; determining a first region where the separator is located in the detection image and a second region where the negative electrode sheet is located in the detection image; and determining the overhang size of the separator and the negative electrode sheet of the region to be detected based on the first region and the second region.

[0043] The method provided in this embodiment, because the insulating part can block all membranes except the current layer membrane in the field of view of the detection camera, ensures that the membrane area identified by the detection camera is the current layer membrane. This allows for accurate measurement of the overhang between the membrane and the negative electrode, improving the accuracy of the detection results. Furthermore, compared to infrared projection detection methods in related technologies, it does not require penetrating multiple layers, eliminating missed detections and false negatives, resulting in more accurate detection results.

[0044] The sixth embodiment of this application provides an overhang size detection device, which includes: an acquisition module for acquiring a detection image of a region to be detected by a detection camera, wherein the region to be detected includes a positive electrode sheet, a separator, and a negative electrode sheet arranged in sequence, the positive electrode sheet, the negative electrode sheet, and the separator being wound or stacked to form a battery cell in any of the above embodiments, the detection camera being located on the side of the negative electrode sheet away from the separator, and the detection image capturing the insulating portion of the negative electrode sheet, the separator, and the positive electrode sheet; a first determination module for determining a first region where the separator is located in the detection image and a second region where the negative electrode sheet is located in the detection image; and a second determination module for determining the overhang size of the separator and the negative electrode sheet of the region to be detected based on the first region and the second region.

[0045] An embodiment of the seventh aspect of this application provides a computing device, including: at least one processor; and at least one memory communicatively connected to the at least one processor, the at least one memory storing instructions that, when executed individually or jointly by the at least one processor, cause the computing device to perform the Overhang size detection method in the above embodiments.

[0046] An embodiment of the eighth aspect of this application provides a computer-readable storage medium storing instructions that, when executed individually or jointly by one or more processors of a computing device, cause the computing device to perform the Overhang size detection method described above.

[0047] An embodiment of the ninth aspect of this application provides a computer program product including instructions that, when executed individually or jointly by one or more processors of a computing device, cause the computing device to perform the Overhang size detection method described above.

[0048] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application. Attached Figure Description

[0049] In the accompanying drawings, unless otherwise specified, the same reference numerals throughout the various drawings denote the same or similar parts or elements. These drawings are not necessarily drawn to scale. It should be understood that these drawings depict only some embodiments disclosed in this application and should not be construed as limiting the scope of this application.

[0050] Figure 1 This is a schematic diagram of the vehicle structure according to some embodiments of this application;

[0051] Figure 2 This is an exploded view of the battery device according to some embodiments of this application;

[0052] Figure 3 This is an exploded structural diagram of a battery cell according to some embodiments of this application;

[0053] Figure 4 This is a schematic diagram of the structure of the positive electrode sheet in some embodiments of this application;

[0054] Figure 5 This is a schematic diagram of the structure of a battery cell according to some embodiments of this application;

[0055] Figure 6 This is a schematic diagram illustrating the detection principle of a battery cell during the winding process in some embodiments of this application;

[0056] Figure 7 This is a schematic diagram of the structure of the part to be detected in the related technology;

[0057] Figure 8 for Figure 7 A bottom view;

[0058] Figure 9 This is a schematic diagram of the structure of the part to be detected in some embodiments of this application;

[0059] Figure 10 for Figure 9 A bottom view;

[0060] Figure 11 This is a schematic diagram of the structure of a battery cell according to another embodiment of this application;

[0061] Figure 12 This is a schematic diagram of the structure of a battery cell according to another embodiment of this application;

[0062] Figure 13 for Figure 12 A schematic diagram of the structure of the positive electrode and insulating components;

[0063] Figure 14 This is a graph showing the relationship between the peel strength of the insulation portion and the immersion time in some embodiments of this application;

[0064] Figure 15 This is a flowchart illustrating the Overhang dimension detection method of some embodiments of this application;

[0065] Figure 16 This is a schematic diagram of an Overhang size detection device according to some embodiments of this application;

[0066] Figure 17 This is a schematic diagram of a computing device for implementing the Overhang dimension detection method, provided for some embodiments of this application.

[0067] Explanation of reference numerals in the attached figures:

[0068] 1000 vehicles;

[0069] Battery device 100, controller 200, motor 300, detection camera 400, winding needle 500;

[0070] Battery cell assembly 10, battery cell 11, positive electrode 110, first body 111, first end of first body 1111, first surface 1112, second surface 1113, first protrusion 1114, second protrusion 1115, first current collector 1116, first active layer 1117, empty foil area 1118, first tab 112, separator 120, first end of separator 121, negative electrode 130, insulating part 140, adhesive layer 141, insulating layer 142;

[0071] End cap 12, housing 13, electrode assembly 14;

[0072] Box 20, Part 1 21, Part 2 22. Detailed Implementation

[0073] The embodiments of the technical solution of this application will now be described in detail with reference to the accompanying drawings. These embodiments are only used to more clearly illustrate the technical solution of this application and are therefore merely examples, and should not be used to limit the scope of protection of this application.

[0074] 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 pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0075] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.

[0076] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0077] In the description of the embodiments in this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, "a and / or b" can represent three cases: a exists alone, a and b exist simultaneously, and b exists alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0078] In the description of the embodiments of this application, the term "multiple" refers to two or more (including two), similarly, "multiple sets" refers to two or more (including two sets), and "multiple pieces" refers to two or more (including two pieces).

[0079] In the description of the embodiments of this 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," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of this application and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application.

[0080] In the description of the embodiments of this application, unless otherwise expressly specified and limited, technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in the embodiments of this application can be understood according to the specific circumstances.

[0081] Currently, the application of rechargeable batteries is becoming increasingly widespread, judging from market trends. They are not only used in energy storage systems for hydropower, thermal power, wind power, and solar power plants, but also extensively in various electronic devices, such as electric bicycles, electric motorcycles, and electric vehicles, as well as in military equipment and aerospace. As the application areas of rechargeable batteries continue to expand, the market demand is also constantly increasing.

[0082] In the battery production process, taking the processing of wound batteries as an example, positive electrode sheets, separators, and negative electrode sheets need to be wound into a single battery cell. The winding process usually requires that the negative electrode sheet exceeds the positive electrode sheet by a certain size, and the separator exceeds the negative electrode sheet by a certain size. That is, it is necessary to ensure the overhang size between the positive and negative electrode sheets, as well as between the separator and the negative electrode sheet. Poor overhang control may lead to direct contact between the positive and negative electrode sheets, resulting in internal short circuits, which may lead to low voltage or even fire hazards.

[0083] In related technologies, infrared projection is usually used to pass through multiple diaphragms to confirm the overhang value between the diaphragm and the negative electrode. However, since infrared radiation needs to pass through multiple diaphragms, it is prone to missed detections and false positives, resulting in low accuracy.

[0084] In addition, related technologies also use CCD (Charge Coupled Device) cameras to capture images of the separator and negative electrode on the winding needle, thereby monitoring the size of the overhang between the two. However, since there are multiple layers of separators wound on the winding needle, it is impossible to accurately identify the separator of the current layer that needs to be measured, resulting in low accuracy of the measured overhang size.

[0085] To improve at least one of the above-mentioned problems, this disclosure provides a battery cell, a battery device, a power-consuming device, and an overhang dimension detection method. The battery cell includes a positive electrode, a negative electrode, and a separator located between the positive and negative electrodes. An insulating portion is provided on the positive electrode near a first tab, protruding from the separator. The optical characteristics of the insulating portion differ from those of the separator, so that the first image of the insulating portion in the detection camera differs from the second image of the separator in the detection camera. This allows the insulating portion to block all separators except the current layer separator in the detection camera's field of view, ensuring that the separator area identified by the detection camera is the current layer separator. This allows for accurate measurement of the overhang dimension between the separator and the negative electrode, improving the accuracy of the detection results.

[0086] The technical solutions described in the embodiments of this application are applicable to battery cells, battery devices containing battery cells, electrical devices using battery devices, and energy storage devices.

[0087] The energy storage device utilizing battery devices as a power source in this application embodiment includes one or more battery clusters to enhance the voltage and capacity of the energy storage device. A battery cluster may include multiple battery devices, which are connected in series via a busbar to increase the voltage of the energy storage device. When the energy storage device includes multiple battery clusters, the multiple battery clusters are connected in parallel to increase the capacity of the energy storage device.

[0088] Energy storage devices can be used in energy storage power stations, wind power generation systems, solar power generation systems, mobile power systems, or temporary power supply systems. Energy storage devices can store electrical energy as needed and output it when appropriate. For example, an energy storage device can store electrical energy during off-peak hours and provide power to relevant users or electrical devices during peak hours. The energy storage system provided in this application embodiment can be any power system that requires energy storage devices. As an example, the energy storage device is an energy storage container or an energy storage cabinet.

[0089] In this application embodiment, the power-consuming device using a battery as a power source can be, but is not limited to, mobile phones, tablets, laptops, electric toys, power tools, electric vehicles, electric cars, ships, spacecraft, etc. Among them, electric toys can include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc., and spacecraft can include airplanes, rockets, space shuttles, and spacecraft, etc.

[0090] It should be understood that the technical solutions described in the embodiments of this application are not limited to the energy storage devices and electrical devices described above, but can also be applied to all battery devices including housings and electrical devices using battery devices. This can help improve the detection accuracy of the overhang dimensions of the separator and negative electrode. However, for the sake of brevity, the following embodiments all use a vehicle as an example of an electrical device for illustration.

[0091] Please refer to Figure 1 , Figure 1 This is a schematic diagram of the structure of a vehicle according to some embodiments of this application. The vehicle 1000 can be a gasoline-powered vehicle, a natural gas-powered vehicle, or a new energy vehicle. The new energy vehicle can be a pure electric vehicle, a hybrid electric vehicle, or a range-extended electric vehicle, etc. A battery device 100 is installed inside the vehicle 1000, and the battery device 100 can be located at the bottom, front, or rear of the vehicle 1000. The battery device 100 can be used to power the vehicle 1000; for example, the battery device 100 can serve as the operating power source for the vehicle 1000. The vehicle 1000 may also include a controller 200 and a motor 300. The controller 200 is used to control the battery device 100 to supply power to the motor 300, for example, to meet the power needs of the vehicle 1000 during starting, navigation, and driving.

[0092] In some embodiments of this application, the battery device 100 can not only serve as the operating power source for the vehicle 1000, but also as the driving power source for the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0093] Please refer to Figure 2 , Figure 2 This is an exploded structural diagram of a battery according to some embodiments of this application. The battery device 100 mentioned in the embodiments of this application may include one or more battery cell assemblies 10 for providing voltage and capacity. The battery cell assembly 10 may include multiple battery cells 11, which are connected in series, parallel, or mixed connection via a busbar.

[0094] In some embodiments, the battery cell assembly 10 is typically formed by arranging a plurality of battery cells 11.

[0095] As an example, the battery cell assembly 10 can be a battery module, which is formed by arranging and fixing multiple battery cells 11 together to form an independent module. As an example, the battery module can be formed by bundling multiple battery cells 11 together with cable ties.

[0096] In some embodiments, such as Figure 2 As shown, the battery device 100 can be a battery pack, which includes a housing 20 and one or more individual battery cells 10, with the individual battery cells 10 housed within the housing 20. The housing 20 can be a simple three-dimensional structure such as a single cuboid, cylinder, or sphere, or a complex three-dimensional structure composed of combinations of simple cuboids, cylinders, or spheres. The material of the housing 20 can be an alloy such as aluminum alloy or iron alloy, a polymer such as polycarbonate or polyisocyanurate foam, or a composite material such as glass fiber and epoxy resin.

[0097] As an example, the battery cell assembly 10 can be a battery module, and the battery cell assembly 10 can be housed in the housing 20 by fixing the battery module in the housing 20.

[0098] As an example, the battery cell assembly 10 can also be housed in the housing 20 by directly fixing multiple battery cells 11 to the housing 20.

[0099] As an example, the housing 20 may include a first part 21 and a second part 22. The first part 21 and the second part 22 are fastened together to form a closed space inside the housing 20 to house the battery cell assembly 10. Here, "closed" refers to covering or closing, and can be either non-sealed or sealed to prevent liquids or other foreign objects from affecting the charging or discharging of the battery cell 11. The first part 21 may be a top cover or a bottom plate.

[0100] As an example, the housing 20 may include a top cover, a frame, and a bottom plate. The top cover and the bottom plate are respectively connected to the frame, so that the interior of the housing 20 forms an enclosed space to accommodate the battery cell assembly 10.

[0101] In some embodiments, the housing 20 may be part of the vehicle's chassis structure. For example, a portion of the housing 20 may be at least a portion of the vehicle's floor, or a portion of the housing 20 may be at least a portion of the vehicle's crossbeams and longitudinal beams.

[0102] The battery cell 11 provided in the embodiments of this application can be a secondary battery. A secondary battery refers to a battery cell 11 that can be used again after being discharged by recharging to activate the active material.

[0103] The battery cell 11 can be a lithium-ion battery, sodium-ion battery, sodium-lithium-ion battery, lithium metal battery, sodium metal battery, lithium-sulfur battery, magnesium-ion battery, nickel-metal hydride battery, nickel-cadmium battery, lead-acid battery, etc., and the embodiments of this application are not limited to this.

[0104] Please refer to Figure 3 , Figure 3 This is an exploded structural diagram of a battery cell according to some embodiments of this application. Battery cell 11 refers to the smallest unit that makes up the battery. Figure 3 The battery cell 11 includes an end cap 12, a housing 13, an electrode assembly 14, and other functional components.

[0105] End cap 12 refers to a component that covers the opening of housing 13 to isolate the internal environment of battery cell 11 from the external environment. The shape of end cap 12 can be adapted to the shape of housing 13 to fit it. In some embodiments, end cap 12 can be made of a material with a certain hardness and strength (such as aluminum alloy), so that end cap 12 is less prone to deformation under pressure and impact, enabling battery cell 11 to have higher structural strength and improved safety performance. Functional components such as electrode terminals can be provided on end cap 12. Electrode terminals can be used for electrical connection with electrode assembly 14 for outputting or inputting electrical energy to battery cell 11. In some embodiments, end cap 12 can also be provided with a pressure relief mechanism for releasing internal pressure when the internal pressure or temperature of battery cell 11 reaches a threshold. The material of end cap 12 can also be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc. In some embodiments, an insulating element may be provided on the inner side of the end cap 12. The insulating element can be used to isolate the electrical connection components within the housing 13 from the end cap 12 to reduce the risk of short circuits. For example, the insulating element may be made of plastic, rubber, etc.

[0106] The housing 13 is a component used to cooperate with the end cap 12 to form the internal environment of the battery cell 11. This internal environment can accommodate the electrode assembly 14, electrolyte, and other components. The housing 13 and the end cap 12 can be independent components. An opening can be provided on the housing 13, and the end cap 12 closes the opening to form the internal environment of the battery cell 11. Alternatively, the end cap 12 and the housing 13 can be integrated. Specifically, the end cap 12 and the housing 13 can form a common connecting surface before other components are inserted into the housing. When it is necessary to encapsulate the interior of the housing 13, the end cap 12 closes the housing 13. The housing 13 can be of various shapes and sizes, such as cuboid, cylindrical, hexagonal prism, etc. Specifically, the shape of the housing 13 can be determined according to the specific shape and size of the electrode assembly 14. The housing 13 can be made of various materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc.

[0107] Electrode assembly 14 is the component in the battery cell 11 where the electrochemical reaction takes place. The housing 13 may contain one or more electrode assemblies 14. Electrode assembly 14 is mainly formed by winding and stacking positive and negative electrode sheets, and a separator is typically provided between the positive and negative electrode sheets. The portions of the positive and negative electrode sheets containing active material constitute the main body of the electrode assembly.

[0108] Figure 4 This is a schematic diagram of the structure of the positive electrode sheet in some embodiments of this application. Figure 5 This is a schematic diagram of the structure of a battery cell according to some embodiments of this application. Figure 6 This is a schematic diagram illustrating the detection principle of battery cells during the winding process in some embodiments of this application. Please refer to 4 to 5. Figure 6 This application provides a battery cell 11, including: a positive electrode 110, a negative electrode 130, and a separator 120 located between the positive electrode 110 and the negative electrode 130.

[0109] The positive electrode 110 includes a first body 111 and a first tab 112 disposed at a first end of the first body 111 along a first direction X. An insulating portion 140 is disposed on the first body 111 near the first tab 112, and the insulating portion 140 protrudes from the first end 1111 of the first body and the first end of the diaphragm 120 along the first direction X. The optical characteristics of the insulating portion 140 are different from the optical characteristics of the diaphragm 120, so that the first image of the insulating portion 140 in the detection camera 400 is different from the second image of the diaphragm 120 in the detection camera 400.

[0110] The battery cell 11 may include one or more electrode assemblies 14, which include a positive electrode 110, a negative electrode 130, and a separator 120 located between the positive electrode 110 and the negative electrode 130. It is understood that the positive electrode 110, the separator 120, and the negative electrode 130 may be wound or stacked to form the electrode assembly 14. For ease of explanation, the following description uses a winding process as an example.

[0111] Figure 4 A positive electrode 110 is shown. The positive electrode 110 includes a first body 111, which is the positive electrode body on which a positive active material can be disposed. The first body 111 can be in the form of a sheet, etc. Figure 4 The upper end of the first body 111 along the first direction X can be the first end 1111 of the first body (the boundary indicated by the dotted line 1111), and the first end 1111 of the first body can be provided with a first electrode tab 112, that is, a positive electrode tab. It can be understood that, as... Figure 3 The first direction X can be the height direction of the battery cell 11. There can be one or more first tabs 112. The first tabs 112 may not have positive electrode active material. These first tabs 112 can be connected to the positive electrode terminal.

[0112] In addition, it can be understood that in this embodiment, the first body 111 may be provided with a first electrode tab 112 at the first end along the first direction X. In other embodiments, the first body 111 may also be provided with a first electrode tab 112 at the second end along the first direction X. That is, the first electrode tab 112 may be located at one end or both ends of the first body 111.

[0113] Similarly, the negative electrode 130 may include a second body, which is the negative electrode body, on which a negative electrode active material may be disposed. The second body may also be in the form of a sheet. A negative electrode active material may also be disposed at one end of the second body along the first direction X. These second tabs may be connected to the negative electrode terminal. In addition, it can be understood that the second tabs may also be disposed at one or both ends of the second body along the first direction X.

[0114] The separator 120 is located between the positive electrode 110 and the negative electrode 130. During the charging and discharging process of the battery cell, the positive and negative active materials can react with the electrolyte. The first tab 112 is connected to the positive electrode terminal and the second tab is connected to the negative electrode terminal to form a current loop.

[0115] An insulating portion 140 may be provided on the first body 111 near the first tab 112. It is understood that the insulating portion 140 is located on the surface of the die-cut edge of the first body. The insulating portion can be made of common insulating materials. It is understood that the insulating portion 140 can be positioned along a winding direction perpendicular to the first direction X. Figure 4It extends in the left-right direction. Furthermore, the insulating portion 140 can protrude from the first end 1111 of the first body, such as... Figure 4 It may partially cover the outside of the first electrode ear 112.

[0116] Figure 5 The diagram shows a partial structure of a battery cell formed by winding or stacking the positive electrode 110, separator 120, and negative electrode 130. For ease of description, only one positive electrode layer, two separator layers, and two negative electrode layers are shown. In this embodiment, the insulating portion 140 protrudes from the first end 1111 of the first body and can further extend to protrude from the first end of the separator 120 along the first direction X. It can be understood that since the wound separator 120 has multiple layers, the size of the insulating portion 140 can be set so that it can protrude from the first end 121 of all the separator layers.

[0117] The insulating part 140 can be disposed on the first body 111 by means of bonding, riveting, integral molding, or other methods. The insulating part has insulating properties; for example, it will not break down under a voltage of 200V and its resistance value is greater than 9999MΩ.

[0118] Furthermore, the optical characteristics of the diaphragm 120 differ from those of the insulating portion 140, allowing the diaphragm 120 and the insulating portion 140 to be distinguished from each other in the field of view of the detection camera 400. That is, the first image of the insulating portion 140 in the detection camera 400 is distinct from the second image of the diaphragm 120 in the detection camera 400. The optical characteristics can be one or more of color, transparency, and haze, depending on whether they can be distinguished by the detection camera.

[0119] Please refer to Figure 6 In this embodiment, during the winding process, the positive electrode 110, the separator 120, and the negative electrode 130 can be wound onto the winding needle 500, and the positive electrode 110 can be located on the inner side closest to the winding needle 500. The detection camera 400 is located on the side of the negative electrode 130 away from the separator 120. The detection camera can be set facing the winding needle so that the part to be detected that it captures is the position where the positive electrode 110, the separator 120, and the negative electrode 130 are just wound onto the winding needle. It can be understood that the part to be detected includes the positive electrode 110, the separator 120, and the negative electrode 130 arranged in sequence. Because conventional overhang setups require the diaphragm to extend beyond the negative electrode and the negative electrode to extend beyond the positive electrode, the positive electrode is usually obscured by the diaphragm in the field of view of the detection camera 400. However, since the insulating portion 140 protrudes from the first end 121 of the diaphragm in this embodiment, the detection image of the detection camera 400 can capture the negative electrode, the diaphragm, and the insulating portion of the positive electrode. Figure 6 Through the winding process, the positive electrode 110, the separator 120 and the negative electrode 130 can form a battery cell 11, such as an electrode assembly constituting a battery cell.

[0120] Figure 7 This is a schematic diagram of the structure of the part to be detected in related technologies. Figure 8 for Figure 7 For the bottom view, please refer to... Figure 7 and Figure 8 In related technologies, the positive electrode sheet has a ceramic coating on its edge. During winding, the winding process forms multiple layers (multiple turns) of separator 120 on the winding needle 500. Due to the influence of winding accuracy, these separator layers 120 may not be perfectly aligned, meaning that the edges of one or more layers may protrude more than the edges of other layers. Figure 7 and Figure 8 The diagram shows two separators, 120a and 120b. Separator 120a is the layer currently being inspected, and separator 120b is the previous layer. Separator 120b slightly protrudes from separator 120a. When performing overhang dimension inspection, the overhang dimension (L2) between the current separator 120a and the negative electrode 130 needs to be accurately measured. However, because separator 120b protrudes from separator 120a and both are made of the same material, the boundary of the current separator 120a cannot be distinguished in the field of view of the inspection camera. Only the outermost boundary of the separator area in the field of view, i.e., the boundary of separator 120b, can be taken as the boundary of the current layer. Therefore, the dimension L1 between separator 120b and the negative electrode 130 is taken as the measured overhang dimension. This leads to a large deviation in inspection accuracy, affecting the processing and control accuracy of the battery cell.

[0121] Figure 9 This is a schematic diagram of the structure of the part to be detected in some embodiments of this application. Figure 10 for Figure 9 A bottom view. Please refer to... Figure 9 and Figure 10 In this embodiment, an insulating portion 140 is provided on the positive electrode 110. Since the insulating portion 140 protrudes from the first end 121 of the separator, that is, the insulating portion 140 protrudes from the separators 120a and 120b, therefore, in the field of view of the detection camera, such as Figure 9 The boundary of the diaphragm 120b is invisible (indicated by dashed lines), and because the optical properties of the diaphragm 120 and the insulating portion 140 are different, the diaphragm 120 and the insulating portion 140 can be accurately distinguished in the inspection image captured by the inspection camera 400, such as... Figure 9In this process, the separators of other layers are blocked by the insulating part, and only the current layer separator 120a is visible in the field of view. By detecting the dimension L2 between the boundary of separator 120a and the boundary of negative electrode 130, the overhang dimension between the current layer separator and negative electrode can be accurately measured. That is, the detection camera can accurately obtain the overhang dimension between the separator and negative electrode of each layer, and can realize real-time monitoring of overhang during the winding process. It can also be applied to the overhang detection of stacked cells.

[0122] Understandable, for ease of explanation Figure 8 and Figure 10 The diaphragm 120a and diaphragm 120b are two adjacent diaphragm layers. Of course, there can be other layers between them, which can be selected according to the actual situation.

[0123] In this embodiment, the insulating portion of the battery cell can block all separators except the current layer separator from the field of view of the detection camera. This ensures that the separator area identified by the detection camera is the current layer separator, thereby enabling accurate measurement of the overhang between the separator and the negative electrode, improving the accuracy of the detection results. Furthermore, compared to infrared projection detection methods in related technologies, it does not require penetration of multiple layers, eliminating missed detections and false negatives, resulting in more accurate detection results.

[0124] Figure 11 This is a schematic diagram of the structure of a battery cell according to another embodiment of this application. Please refer to... Figure 5 and Figure 11 According to some embodiments of this application, the first body 111 has a first surface 1112 and a second surface 1113 disposed opposite to each other along the second direction Y, and an insulating portion 140 is disposed on the first surface 1112 or the second surface 1113; wherein the first direction X is perpendicular to the second direction Y.

[0125] It can be understood that the first body 111 can be a sheet-like structure, the second direction Y can be the thickness direction of the first body 111, that is, the direction perpendicular to the first body 111, and the first surface 1112 and the second surface 1113 can be the two surfaces with the larger area. The positive electrode active material can be disposed on the first surface 1112 and the second surface 1113.

[0126] like Figure 5 The insulating portion 140 may be located on the first surface 1112, for example... Figure 11 The insulating part 140 may be located on the second surface 1113.

[0127] By placing the insulating portion on either the first or second surface of the first body, the membrane of the layers other than the current layer can be blocked during the winding process, thereby accurately detecting the boundary of the current layer's membrane and improving the accuracy of the overhang dimension detection between the membrane and the negative electrode.

[0128] Figure 12 This is a schematic diagram of the structure of a battery cell according to another embodiment of this application. Please refer to... Figure 12 According to some embodiments of this application, the first body 111 has a first surface 1112 and a second surface 1113 disposed opposite to each other along the second direction Y. Both the first surface 1112 and the second surface 1113 are provided with insulating portions 140, wherein the first direction X is perpendicular to the second direction Y.

[0129] In this embodiment, the first surface 1112 and the second surface 1113 are the two side surfaces of the first body 111 along its thickness direction (second direction Y), and both the first surface 1112 and the second surface 1113 can be provided with an insulating portion 140. The insulating portions 140 on the first surface 1112 and the insulating portions 140 on the second surface 1113 can be symmetrically arranged.

[0130] By providing insulating portions on both the first and second surfaces of the first body, the insulating portions can shield the membranes of the remaining layers except the current layer during the winding process, thereby accurately detecting the boundary of the current layer's membrane and improving the accuracy of the overhang dimension detection between the membrane and the negative electrode.

[0131] Figure 13 for Figure 12 Please refer to the structural diagram of the positive electrode and insulating components. Figures 12 to 13 According to some embodiments of this application, the insulating portion 140 disposed on the first surface 1112 has a first protrusion 1114 protruding from the first surface 1112, and the insulating portion 140 disposed on the second surface 1113 has a second protrusion 1115 protruding from the second surface 1113, and the first protrusion 1114 and the second protrusion 1115 are connected.

[0132] It is understood that the insulating portion 140 protrudes from the first body 111. When insulating portions 140 are provided on both sides of the first body 111, the portion of the insulating portion 140 protruding from the first surface 1112 can be a first protrusion 1114, and the portion of the insulating portion 140 protruding from the second surface 1113 can be a second protrusion 1115. The first protrusion 1114 and the second protrusion 1115 are respectively the portions of the insulating portions protruding from the first end of the first body.

[0133] In this embodiment, the first protrusion 1114 and the second protrusion 1115 can be connected to each other. For example, they can be bonded together by means of adhesive bonding, welding, etc., or the first protrusion 1114 and the second protrusion 1115 can be connected by processes such as integral molding.

[0134] It is understood that at the location with the first tab 112, the first protrusion 1114 and the second protrusion 1115 can be separated by the first tab 112, while at the location without the first tab 112, the two can be connected to each other directly or indirectly.

[0135] It is understandable that during the die-cutting process, the edge of the first body 111 may have burrs. By connecting the first protrusion 1114 and the second protrusion 1115, the first end 1111 of the first body can be covered, thereby covering the burrs and improving the problem of low voltage or safety caused by burrs easily tearing or scratching the diaphragm.

[0136] In some embodiments, please refer to Figure 4 According to some embodiments of this application, the first body 111 includes a first current collector 1116 and a first active layer 1117 disposed on the surface of the first current collector 1116. The first current collector 1116 has an empty foil area 1118 protruding from the first active layer 1117. A first tab 112 is disposed at the first end of the empty foil area 1118 along the first direction X. An insulating portion 140 covers the empty foil area 1118 and also covers a portion of the first active layer 1117.

[0137] The first current collector 1116 can be made of materials such as aluminum foil, and the first active layer 1117 can be a layer structure made of a positive electrode active material such as lithium iron phosphate. It can be understood that the first active layer 1117 can be provided on both sides of the first current collector 1116.

[0138] Understandable, such as Figure 4 The first active layer 1117 does not completely cover the surface of the first current collector 1116. It may be a certain distance from the first end of the first current collector 1116. This part of the first current collector 1116 that is not coated with positive electrode active material is called the empty foil area 1118.

[0139] In this embodiment, the first end of the empty foil area 1118 along the first direction X can be the first end 1111 of the first body, and the first tab 112 can be connected to the first end of the empty foil area 1118.

[0140] The insulating portion 140 may cover the empty foil area 1118 and protrude from the first end of the first current collector 1116. In addition, the insulating portion 140 may extend along the first direction X to cover the first active layer 1117.

[0141] By setting an insulating layer in the empty foil area and extending the insulating layer to the first active layer covering the area, the insulating layer can completely cover the empty foil area, avoiding the risk of the empty foil area being exposed.

[0142] Continue to refer to Figure 4 According to some embodiments of this application, the width H1 of the empty foil area 1118 along the first direction satisfies: 1.5mm≤H1≤3.5mm.

[0143] In this embodiment, the width H1 of the empty foil area 1118 can be 1.5mm, 1.6mm, 1.7mm, 1.8mm, 1.9mm, 2mm, 2.1mm, 2.2mm, 2.3mm, 2.4mm, 2.5mm, 2.6mm, 2.7mm, 2.8mm, 2.9mm, 3mm, 3.1mm, 3.2mm, 3.3mm, 3.4mm, 3.5mm, etc.

[0144] In some embodiments, 1.6mm≤H1≤3.2mm, or 1.8mm≤H1≤3mm, or 2mm≤H1≤2.8mm, or 1.5mm≤H1≤3mm, etc.

[0145] In this embodiment, by setting the width H1 of the empty foil area to be greater than or equal to 1.5 mm, the phenomenon of coating overflow during the application of positive electrode active material can be avoided. By setting H1 to be less than or equal to 3.5 mm, the area of ​​positive electrode active material on the positive electrode sheet can be increased, thereby increasing the energy density of the battery cell.

[0146] Continue to refer to Figure 4 According to some embodiments of this application, the width H2 of the portion of the insulating portion 140 covering the first active layer 1117 along the first direction satisfies: 0.1mm≤H2≤2mm.

[0147] In this embodiment, the width H2 of the portion of the insulating part 140 covering the first active layer 1117 can be 0.1mm, 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1mm, 1.1mm, 1.2mm, 1.3mm, 1.4mm, 1.5mm, 1.6mm, 1.7mm, 1.8mm, 1.9mm, 2mm, etc.

[0148] In some embodiments, 0.3mm≤H2≤1.7mm, or 0.5mm≤H2≤1.5m, or 0.8mm≤H2≤1.2m, or 0.1mm≤H2≤1.5m, etc.

[0149] By setting the width of the portion of the insulating part covering the first active layer to be greater than or equal to 0.1 mm, the empty foil area can be completely covered, improving the risk of easy exposure of the empty foil area. By setting H2 to less than or equal to 2 mm, the area of ​​effective positive electrode active material on the positive electrode sheet can be increased, thereby increasing the energy density of the battery cell.

[0150] Continue to refer to Figure 4 According to some embodiments of this application, the width H3 of the insulating portion 140 along the first direction satisfies: 4.5mm≤H3≤12mm.

[0151] In this embodiment, the width H3 of the insulating part 140 can be 4.5mm, 5mm, 5.5mm, 6mm, 6.5mm, 7mm, 7.5mm, 8mm, 8.5mm, 9mm, 9.5mm, 10mm, 10.5mm, 11mm, 11.5mm, 12mm, etc.

[0152] In some embodiments, 5mm≤H3≤11mm, or 6mm≤H3≤10mm, or 7mm≤H3≤9mm, or 5mm≤H3≤10mm, etc.

[0153] By setting the width H3 of the insulating part to be greater than or equal to 4.5 mm, the insulating part can protrude from the separator. This allows the insulating part to completely cover the separator layers other than the current layer in the inspection image from the inspection camera, thereby improving the accuracy of the overhang dimension detection between the separator and the negative electrode. Simultaneously, by setting the width of the insulating part to be less than or equal to 12 mm, excessive volume is avoided, increasing the battery's energy density. Furthermore, excessive height of the insulating part prevents it from interfering with the connection between the first tab and the electrode terminal.

[0154] Please refer to Figure 13 According to some embodiments of this application, the insulating part 140 includes an adhesive layer 141 and an insulating layer 142. One side of the adhesive layer 141 is bonded to the insulating layer 142, and the other side of the adhesive layer 141 is bonded to the first body 111.

[0155] Understandable. Figure 13 In this process, the adhesive layer 141 can be disposed on the entire surface of the insulating layer 142. The portion of the adhesive layer 141 located on the surface of the first body 111 can bond the insulating layer 142 and the first body 111, while the portion of the adhesive layer 141 protruding from the first end 1111 of the first body can be connected to the adhesive layer 141 in the insulating portion 140 on the other side of the first body, thereby enabling the insulating portions 140 on both sides of the first body 111 to be connected.

[0156] In this embodiment, the insulating part 140 can be an insulating adhesive paper with an adhesive layer 141 and an insulating layer 142, which simplifies the processing and assembly of the insulating part 140, making it more convenient and lower in cost.

[0157] Additionally, please refer to Figure 11 When an insulating portion 140 is provided on one side surface of the first body 111, the adhesive layer 141 can be located only on the first body 111, that is, the adhesive layer 141 can not cover the entire insulating layer 142, and it only exists between the first body 111 and the insulating layer 142. The adhesive layer 141 is not provided on the part of the insulating layer 142 that protrudes from the first body, thereby realizing the connection between the insulating portion 140 and the first body 111, and at the same time preventing the adhesive layer 141 from being too large and bonding with other layers.

[0158] By setting an adhesive layer and an insulating layer, the processing of the insulating part and its connection with the first body can be simplified, improving processing and assembly efficiency, while reducing costs.

[0159] According to some embodiments of this application, the constituent material of the insulating layer 142 includes at least one of polyethylene terephthalate, polypropylene, polyethylene, and polypropylene block copolymers.

[0160] It is understood that the insulating layer 142 can be composed of polyethylene terephthalate (PET), polypropylene, polyethylene, or polypropylene block copolymer. Of course, the insulating layer 142 can also be composed of multiple of the above materials. For example, it can be composed of polyethylene terephthalate and polypropylene, or polypropylene and polyethylene. The specific composition can be determined according to the actual situation.

[0161] The insulating layer made of the above materials can maintain electrochemical stability in the electrolyte, thereby achieving insulation, and the materials are low in cost.

[0162] According to some embodiments of this application, the constituent material of the adhesive layer 141 includes at least one of polyolefin, polyester, and styrene-isobutylene copolymer.

[0163] It is understood that the adhesive layer 141 can be composed of polyolefin, polyester, or styrene-isobutylene copolymer. Of course, the adhesive layer 141 can also be composed of multiple of the above materials. For example, it can be composed of polyolefin and polyester, or it can be composed of polyester and styrene-isobutylene copolymer. The specific composition can be set according to the actual situation.

[0164] The adhesive layer made of the above materials can achieve the connection between the insulating layer and the first body, with high connection reliability and low material cost.

[0165] According to some embodiments of this application, the light transmittance A of the insulating portion 140 satisfies: 65% ≤ A ≤ 80%.

[0166] In this embodiment, optical properties may include light transmittance, which refers to the ability of light to pass through a medium and is the percentage of luminous flux passing through a transparent or translucent body relative to the incident luminous flux. In this embodiment, the insulating part may be a white translucent structure. It can be understood that when the insulating part includes an adhesive layer and an insulating layer, the insulating part as a whole may be a white translucent structure.

[0167] In this embodiment, the light transmittance A of the insulating part 140 can be 65%, 66%, 67%, 68%, 69%, 70%, 71%, 72%, 73%, 74%, 75%, 76%, 77%, 78%, 79%, 80%, etc.

[0168] In some embodiments, 66% ≤ A ≤ 79%, or 68% ≤ A ≤ 78%, or 70% ≤ A ≤ 76%, or 65% ≤ A ≤ 70%, etc.

[0169] By setting the light transmittance to be greater than or equal to 65%, the diaphragm 120 and the insulating part 140 can be distinguished. At the same time, by setting the light transmittance to be less than or equal to 80%, the diaphragm can be effectively blocked within the field of view of the detection camera.

[0170] According to some embodiments of this application, the haze B of the insulation portion satisfies: 60% ≤ B ≤ 100%.

[0171] In this embodiment, optical characteristics may include haze, which is the percentage of transmitted light intensity that deviates from the incident light angle by more than 2.5° out of the total transmitted light intensity. Higher haze means a decrease in the gloss and transparency of the insulating part, especially in image quality. It can be understood that when the insulating part includes an adhesive layer and an insulating layer, the overall haze B of the insulating part is in the range of 60%-100%.

[0172] In this embodiment, the haze B of the insulating part 140 can be 60%, 61%, 62%, 63%, 64%, 65%, 66%, 67%, 68%, 69%, 70%, 71%, 72%, 73%, 74%, 75%, 76%, 77%, 78%, 79%, 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, 100%, etc.

[0173] In some embodiments, 65% ≤ B ≤ 95%, or 70% ≤ B ≤ 90%, or 75% ≤ B ≤ 85%, or 72% ≤ B ≤ 80%, etc.

[0174] By setting the haze level to be greater than or equal to 60% and less than or equal to 100%, the insulating part 140 can be in a high haze condition, which can effectively block the diaphragm within the field of view of the detection camera. At the same time, it can be distinguished from the diaphragm within the field of view of the camera, which helps to improve the accuracy of detection.

[0175] Continue to refer to Figure 5 According to some embodiments of this application, the thickness H4 of the insulating portion 140 along the second direction Y perpendicular to the first direction X satisfies: 9μm≤H4≤30μm.

[0176] In this embodiment, the second direction Y is the thickness direction of the positive electrode sheet. The thickness H4 of the insulating portion 140 along the second direction Y can be 9μm, 10μm, 11μm, 12μm, 13μm, 14μm, 15μm, 16μm, 17μm, 18μm, 19μm, 20μm, 21μm, 22μm, 23μm, 24μm, 25μm, 26μm, 27μm, 28μm, 29μm, or 30μm.

[0177] In some embodiments, 10μm≤H4≤28μm, or 12μm≤H4≤25μm, or 14μm≤H4≤23μm, or 15μm≤H4≤20μm, etc.

[0178] By setting the thickness of the insulating part to be greater than or equal to 9μm, its puncture strength can be improved, and it can be prevented from being punctured or scratched by burrs. In addition, by setting the thickness of the insulating part to be less than or equal to 30μm, it can be prevented that the insulating part protrudes too much from the first body in the second direction, reducing the risk of edge bulging due to poor size control, and improving the energy density of the battery cell.

[0179] According to some embodiments of this application, when the insulation portion 140 is immersed in the electrolyte for 1000 hours, the peel strength C of the insulation portion 140 satisfies: 15 N / m ≤ C ≤ 20 N / m.

[0180] Peel strength refers to the maximum force required to peel bonded materials apart per unit width from the contact surface. In this embodiment, since the positive electrode 110 needs to be immersed in the electrolyte, the peel strength of the insulating portion 140 refers to the peel strength of the insulating portion after immersion in the electrolyte for 1000 hours.

[0181] The peel strength C of the insulation can be 15N / m, 16N / m, 17N / m, 18N / m, 19N / m, 20N / m, etc.

[0182] In some embodiments, 16 N / m ≤ C ≤ 20 N / m, or 17 N / m ≤ C ≤ 20 N / m, or 18 N / m ≤ C ≤ 20 N / m, or 19 N / m ≤ C ≤ 20 N / m, etc.

[0183] Peel strength can be measured experimentally. For example, a sample is made by attaching an insulating part 140 with a thickness of 13 μm and a width of 8 mm to a first body (e.g., aluminum foil) with a thickness of 13 μm. The sample is then immersed in an electrolyte at 70°C for 200 h, 400 h, 600 h, 800 h, and 1000 h, and then removed to test its peel strength.

[0184] During testing, a high-speed rail tensile testing machine can be used. After soaking in liquid, the sample is bonded to a stainless steel plate with double-sided tape, with the side of the adhesive part facing outward and pressed firmly with a pressure roller. The entire sample is fixed on the tensile testing machine. The tensile testing machine is used to clamp one end of the adhesive tape and pull the insulation part upward at a 180° angle and a speed of 50 mm / min until the insulation part is completely peeled off from the aluminum foil. The displacement and force during the process are recorded.

[0185] Figure 14 For a graph showing the relationship between the peel strength of the insulation portion and the immersion time in some embodiments of this application, please refer to... Figure 14 After immersion for 200 hours, the peel strength was 112.45 N / m; after immersion for 400 hours, the peel strength was 29.12 N / m; after immersion for 600 hours, the peel strength was 19.79 N / m; after immersion for 800 hours, the peel strength was 18.11 N / m; and after immersion for 1000 hours, the insulation did not detach from the aluminum foil, and the peel strength was greater than 19 N / m, which meets the range of peel strength C.

[0186] By setting the peel strength of the insulation part to be greater than or equal to 15 N / m, the reliability of the connection between the insulation part and the first body can be improved. By setting the peel strength of the insulation part to be less than or equal to 20 N / m, the insulation part and the first body can be easily separated when needed, thereby balancing the reliability and detachability of the connection.

[0187] According to some embodiments of this application, the puncture strength D of the insulating part 140 satisfies: D≥400gf.

[0188] Puncture strength refers to the maximum force applied to the needle to penetrate a fixed, ring-shaped object at a certain speed (e.g., 3-5 meters per minute). The puncture strength D of the insulating part 140 can be greater than or equal to 400 gf, for example, 410 gf, 420 gf, 430 gf, 440 gf, 450 gf, 460 gf, 470 gf, 480 gf, 490 gf, 500 gf, etc.

[0189] In some embodiments, D ≥ 402gf, or D ≥ 405gf, or D ≥ 407gf, or D ≥ 410gf, etc.

[0190] In this embodiment, a 50mm × 50mm insulating portion with a thickness of 13μm can be used for testing. A steel needle with a diameter of 1mm is used, and the test is conducted on a puncture tester. The force when the insulating portion is punctured is recorded at a speed of 50mm / min. The reference standard can be GB / T 36363-2018.

[0191] Table 1 shows the results of the puncture strength test. As shown in Table 1, after 10 puncture tests, the puncture strengths of the insulation part were 416.33 gf, 414.29 gf, 428.57 gf, 423.47 gf, 420.41 gf, 430.61 gf, 414.29 gf, 433.67 gf, 426.53 gf, and 444.90 gf, respectively. The average value of these results is 425.31 gf. Therefore, it can be seen that the puncture strength D of the insulation part 140 meets the requirement of being greater than or equal to 400 gf.

[0192] Table 1

[0193]

[0194] By setting the puncture strength of the insulation part to be greater than or equal to 400gf, it is possible to prevent the insulation part from being punctured by the burrs on the edge of the first body, thereby improving the reliability of the battery cell.

[0195] According to some embodiments of this application, the insulating portion 140 has electrochemical stability when the voltage U satisfies 2.5V≤U≤4.5V.

[0196] Electrochemical stability refers to the ability of a material to resist decomposition or irreversible reaction under a specific electrochemical environment (in this example, the voltage U satisfies 2.5V≤U≤4.5V).

[0197] The electrochemical stability of the insulation can also be tested experimentally. For example, conductive carbon black and hot melt adhesive are mixed in a mass ratio of 7:3, and then N-methylpyrrolidone solvent is added and dispersed evenly to obtain a slurry. The solid content of the slurry is controlled at 7-10%. The slurry is coated onto aluminum foil and dried to obtain a positive electrode sheet. The prepared positive electrode sheet is then used to make button cells (samples 1-5) in a glove box for cyclic voltammetry testing. The test conditions can be as follows: scan at a speed of 0.1 mV / s for 3 cycles and observe whether redox peaks appear in the voltage range of 2.5-5V. Plot the current-voltage curve and record the voltage at which the first oxidation peak appears to determine the electrochemical stability of the material.

[0198] Table 2 shows the results of the electrochemical stability experiment. As shown in Table 2, the oxidation voltage at which the oxidation peak appeared for sample 1 was 4.6V, for sample 2 it was 4.7V, for sample 3 it was 4.6V, for sample 4 it was 4.6V, and for sample 5 it was 4.7V. It can be seen that no redox reaction occurred in the insulating part within the voltage range of 2.5-4.5V, indicating electrochemical stability.

[0199] Table 2

[0200] sample Sample 1 Sample 2 Sample 3 Sample 4 Sample 5 Oxidation voltage (V) 4.6 4.7 4.6 4.6 4.7

[0201] When the voltage U satisfies 2.5V≤U≤4.5V, no oxidation-reduction reaction will occur in the insulation part, which can keep the insulation part stable during the operation of the battery cell and improve the reliability of the battery cell.

[0202] This embodiment also provides a specific method for preparing a battery cell 11, which may include the following steps:

[0203] (1) Preparation of positive electrode:

[0204] The positive electrode active material LiFePO4 (LFP, lithium iron phosphate), binder polyvinylidene fluoride (PVDF), and conductive carbon black (Super P) were uniformly mixed at a mass ratio of LPF:PVDF:Super P = 95:3:2. The mixed slurry was dispersed using 1-methyl-2-pyrrolidone (NMP) as the solvent. The resulting positive electrode slurry was coated on both sides of an aluminum foil. After drying, rolling, die-cutting, and slitting, adhesive was applied, with the width of the empty foil area being 3 mm. The insulating part (using insulating tape) was attached to the die-cut edge. The width of the insulating tape covering the positive electrode active material (first active layer) on the first and second surfaces of the positive electrode sheet was 0.5 mm.

[0205] In one specific embodiment, the insulating tape may be selected with a substrate (insulating layer) of polypropylene (PP) with a thickness of 10μm; an adhesive layer (adhesive layer) of polyacrylate with a thickness of 3μm; a total thickness of 13μm, a width of 8mm, a white color, a light transmittance of 71%, and a haze of 70%.

[0206] (2) Preparation of negative electrode sheet:

[0207] The negative electrode active material graphite, binder (SBR) and conductive carbon black (Super P) are uniformly mixed in a mass ratio of graphite:SBR:Super P = 94:4:2. Deionized water is used as a solvent to disperse the mixed slurry. The negative electrode slurry is coated on both sides of copper foil, and after drying, rolling, die cutting and slitting, the negative electrode sheet is obtained.

[0208] (3) Membrane preparation:

[0209] The base membrane for the diaphragm can be a polypropylene (PP) diaphragm with a thickness of 7μm.

[0210] (4) Electrode assembly fabrication:

[0211] The prepared positive electrode sheet, separator and negative electrode sheet are wound, then hot-pressed and shaped, and the electrode tabs are welded to obtain the electrode assembly (bare cell).

[0212] (5) Electrolyte preparation:

[0213] Lithium hexafluorophosphate (LFPF6) was added to ethylene carbonate (EC) in successive batches, and the mass fraction of LiPF6 in the electrolyte was controlled to be 12.5% ​​to obtain the electrolyte.

[0214] (6) Battery cell assembly:

[0215] The electrode assembly is placed in the aluminum shell of the outer packaging. The positive and negative electrode tabs and the top cover post are welded and dried. The prepared electrolyte is injected into the dried battery cell. The lithium-ion battery cell is prepared by standing, forming, and capacity testing.

[0216] In addition, to verify the electrical performance of the battery cell provided in this embodiment, a comparative example can be manufactured for comparative experiments.

[0217] The comparative example can be prepared with a positive electrode, a separator, and a negative electrode. The difference between the manufacturing method and the above embodiment is that the positive electrode can use a conventional ceramic coating instead of insulating paper. Then, the positive electrode, separator, and negative electrode are wound together, with the separator positioned in the middle of the positive and negative electrodes. After winding, the electrode assembly is shaped by hot pressing and then the tabs are welded to obtain the electrode assembly of the comparative example. The preparation of the electrolyte and the assembly of the comparative example can refer to steps (5) and (6) in the above preparation method.

[0218] It is understood that the battery cells provided in the comparative example and this embodiment do not show significant differences in the conventional electrical performance test items. These conventional test items include capacity, rate charging, rate discharging, high and low temperature DCR (Direct Current Resistance), high and low temperature capacity, long-term storage, and long-term cycling.

[0219] This application embodiment also provides a battery device 100, such as Figure 2 As shown, it includes the battery cell 11 in the above embodiments.

[0220] It is understood that the battery device 100 provided in this application has all the beneficial effects of the battery cell 11 mentioned above because it uses any of the aforementioned battery cells 11, and will not be described in detail here.

[0221] This application provides an electrical device, which includes the battery device 100 in the above embodiments, and the battery device 100 is used to provide electrical energy.

[0222] Electrical devices include vehicles (such as cars, electric vehicles, ships, spacecraft, etc.), display devices (such as mobile phones, tablets, laptops, etc.), electric toys, power tools, etc.

[0223] It is understood that the electrical device provided in this application, by using any of the aforementioned battery cells 11, has all the beneficial effects of the aforementioned battery cells 11, which will not be elaborated here.

[0224] This application provides an energy storage device, which includes the battery device 100 in the above embodiments, and the battery device 100 is used to store electrical energy.

[0225] Energy storage devices can include, but are not limited to, centralized energy storage devices (such as containerized energy storage devices), distributed energy storage devices, mobile energy storage devices, wearable energy storage devices, and so on.

[0226] It is understood that the energy storage device provided in this application, by using any of the aforementioned battery cells 11, has all the beneficial effects of the aforementioned battery cells 11, which will not be elaborated here.

[0227] Figure 15 The following is a flowchart illustrating the Overhang dimension detection method of some embodiments of this application. Please refer to... Figure 6 , Figure 9 , Figure 10 as well as Figure 15 According to some embodiments of this application, an overhang size detection method 600 is provided, which includes the following steps S610 to S630.

[0228] In step S610, a detection image of the part to be detected is acquired by the detection camera 400. The part to be detected includes a positive electrode 110, a separator 120 and a negative electrode 130 arranged in sequence. The positive electrode 110, the separator 120 and the negative electrode 130 are wound or stacked to form a battery cell as described in any of the above embodiments. The detection camera 400 is located on the side of the negative electrode 130 away from the separator 120, and the detection image captures the insulating portion 140 in the negative electrode 130, the separator 120 and the positive electrode 110.

[0229] Step S620: Determine the first region where the diaphragm 120 is located in the detection image and the second region where the negative electrode 130 is located in the detection image.

[0230] Step S630: Based on the first region and the second region, determine the overhang dimensions of the diaphragm and the negative electrode at the part to be tested.

[0231] Please refer to Figure 6 In this embodiment, method 600 can be used in the processing of battery cell 11 in any of the above embodiments. Battery cell 11 can be formed by winding or stacking positive electrode 110, separator 120 and negative electrode 130. The structure of battery cell 11 and positive electrode 110 can refer to the battery cell and positive electrode in the above embodiments, and will not be repeated. Taking the winding process as an example, during the winding process, the positive electrode 110, the separator 120, and the negative electrode 130 can be wound onto the winding needle 500, and the positive electrode 110 can be located on the inner side closest to the winding needle 500. The detection camera 400 is located on the side of the negative electrode 130 away from the separator 120. The detection camera can be set directly opposite the winding needle so that the area to be detected is the position where the positive electrode 110, the separator 120, and the negative electrode 130 are just wound onto the winding needle. It can be understood that the area to be detected includes the positive electrode 110, the separator 120, and the negative electrode 130 arranged in sequence. Since conventional overhang settings require the separator to extend beyond the negative electrode and the negative electrode to extend beyond the positive electrode, the positive electrode is usually blocked by the separator in the field of view of the detection camera 400. However, since the insulating part 140 protrudes from the first end 121 of the separator in this embodiment, therefore, as Figure 9 As shown, the detection image from the detection camera 400 can capture images of the negative electrode, the separator, and the insulating portion of the positive electrode.

[0232] Step S610 can acquire a detection image of the part to be detected by the detection camera. It can be understood that the detection camera can automatically acquire a detection image of the part to be detected at a set time interval.

[0233] Step S620 can process the detected image, such as performing grayscale processing. Because the diaphragm and the insulating part have different optical properties, it is possible to distinguish the diaphragm, the insulating part, and the negative electrode in the processed intermediate image. Figure 9 As shown, the first region where the separator is located can be the white region shown in 120a, and the second region where the negative electrode is located can be the grid region shown in 130.

[0234] Step S630 can measure the overhang dimensions of the separator and the negative electrode based on the boundary of the region. Figure 10 The dimension L2 in the middle.

[0235] In this embodiment, an insulating portion 140 is provided on the positive electrode 110. Since the insulating portion 140 protrudes from the first end 121 of the separator, that is, the insulating portion 140 protrudes from the separators 120a and 120b, therefore, in the field of view of the detection camera, such as Figure 9The boundary of the diaphragm 120b is invisible (indicated by dashed lines), and because the optical properties of the diaphragm 120 and the insulating portion 140 are different, the diaphragm 120 and the insulating portion 140 can be accurately distinguished in the inspection image captured by the inspection camera 400, such as... Figure 9 In this field of view, the membranes of other layers are blocked by the insulating part, and only the current layer membrane 120a is visible. By detecting the dimension L2 between the boundary of the membrane 120a and the boundary of the negative electrode 130, the overhang dimension between the current layer membrane and the negative electrode can be accurately measured.

[0236] The method provided in this embodiment, because the insulating part can block all membranes except the current layer membrane in the field of view of the detection camera, ensures that the membrane area identified by the detection camera is the current layer membrane. This allows for accurate measurement of the overhang between the membrane and the negative electrode, improving the accuracy of the detection results. Furthermore, compared to infrared projection detection methods in related technologies, it does not require penetrating multiple layers, eliminating missed detections and false negatives, resulting in more accurate detection results.

[0237] Figure 16 The above diagram is a schematic diagram of the Overhang size detection device according to some embodiments of this application. Please refer to... Figure 16 This application provides an overhang size detection device 700, which includes the following modules:

[0238] The acquisition module 710 is used to acquire a detection image of the part to be detected by a detection camera. The part to be detected includes a positive electrode sheet, a separator, and a negative electrode sheet arranged in sequence. The positive electrode sheet 110, the separator 120, and the negative electrode sheet 130 are wound or stacked to form a battery cell as described in any of the above embodiments. The detection camera is located on the side of the negative electrode sheet away from the separator, and the detection image captures the insulating parts of the negative electrode sheet, the separator, and the positive electrode sheet.

[0239] The first determining module 720 is used to determine the first region where the diaphragm is located in the detection image and the second region where the negative electrode is located in the detection image.

[0240] The second determining module 730 is used to determine the overhang dimensions of the diaphragm and the negative electrode at the part to be tested based on the first region and the second region.

[0241] The acquisition module 710, the first determination module 720, and the second determination module 730 can respectively correspond to S610 to S630 in the Overhang dimension detection method, and will not be described in detail here for the sake of brevity. It should be understood that, corresponding to the embodiments of the Overhang dimension detection method, the Overhang dimension detection device 600 may also include more modules.

[0242] It should be noted that the functions of the modules discussed herein can be divided into multiple modules, and / or at least some functions of multiple modules can be combined into a single module. The specific actions performed by a particular module discussed herein include the specific module itself performing the action, or alternatively, the specific module calling or otherwise accessing another component or module that performs the action (or performs the action in conjunction with the specific module). Therefore, a specific module performing an action can include the specific module performing the action itself and / or another module that performs the action, called or otherwise accessed by the specific module.

[0243] It should also be understood that this article can describe various technologies in the general context of software and hardware components or program modules. The above regarding... Figure 16 The described modules can be implemented in hardware or in hardware in combination with software and / or firmware. For example, these modules can be implemented as computer program code / instructions configured to execute in one or more processors and stored in a computer-readable storage medium. Alternatively, these modules can be implemented as hardware logic / circuit. Hardware logic / circuit may include integrated circuit chips (which include processors (e.g., Central Processing Unit (CPU), microcontrollers, microprocessors, digital signal processors (DSPs), etc.), memory, one or more communication interfaces, and / or one or more components of other circuitry), and may optionally execute received program code and / or include embedded firmware to perform functions.

[0244] Figure 17 This is a schematic diagram of a computing device used to implement the Overhang dimension detection method, provided for some embodiments of this application. Figure 17 As shown, this application embodiment also provides a computing device 800, including: at least one processor 805; and at least one memory 807 communicatively connected to at least one processor 805, the at least one memory 807 storing instructions, which, when executed individually or jointly by at least one processor 805, cause the computing device to perform the method of any of the above embodiments.

[0245] The computing device 800 may include at least one processor 805 capable of communicating with each other, such as via a bus 804 or other suitable connection, a memory 807, multiple communication interfaces 802, a display device 801, other input / output (I / O) devices 803, and one or more mass storage devices 806. Instructions are stored on the memory 807 that, when executed by the processor 805, cause the processor 805 to perform the Overhang size detection method as described in the above embodiments.

[0246] Processor 805 may be a single processing unit or multiple processing units, and all processing units may include single or multiple computing units or multiple cores. Processor 805 may be implemented as one or more microprocessors, microcomputers, microcontrollers, digital signal processors, central processing units, state machines, logic circuits, and / or any computing device that manipulates signals based on operating instructions. Among other capabilities, processor 805 may be configured to acquire and execute computer-readable instructions stored in memory 807, mass storage device 806, or other computer-readable media, such as program code of operating system 808, program code of application program 809, program code of other program 810, etc.

[0247] Memory 807 and mass storage device 806 are examples of computer-readable storage media for storing instructions that are executed by processor 805 to perform the various functions described above. For example, memory 807 may generally include both volatile and non-volatile memory (e.g., RAM, ROM, etc.). Furthermore, mass storage device 806 may generally include hard disk drives, solid-state drives, removable media, including external and removable drives, memory cards, flash memory, floppy disks, optical disks (e.g., CDs, DVDs), storage arrays, network-attached storage, storage area networks, etc. Both memory 807 and mass storage device 806 may be collectively referred to herein as memory or computer-readable storage media, and may be non-transitory media capable of storing computer-readable, processor-executable program instructions as computer program code, which may be executed by processor 805 as a specific machine configured to perform the operations and functions described in the examples herein.

[0248] Multiple programs may be stored on mass storage device 806. These programs include operating system 808, one or more application programs 809, other programs 810, and program data 811, and they may be loaded into memory 807 for execution. Examples of such application programs or program modules may include, for example, computer program logic (e.g., computer program code or instructions) for implementing the following components / functions: Overhang size detection device 700 (including acquisition module 710, first determination module 720, and second determination module 730), Overhang size detection method 600 (including any suitable steps of Overhang size detection method 600), and / or other embodiments described herein.

[0249] Although Figure 17The data is illustrated as being stored in memory 807 of computing device 800, but operating system 808, application program 809, other programs 810 and program data 811 or portions thereof may be implemented using any form of computer-readable medium accessible by computing device 800.

[0250] One or more communication interfaces 802 are used for exchanging data with other computing devices, such as via a network, direct connection, etc. Such communication interfaces can be one or more of the following: any type of network interface (e.g., a network interface card (NIC)), wired or wireless (such as IEEE 802.11 Wireless LAN (WLAN)) interface, Wi-MAX interface, Ethernet interface, Universal Serial Bus (USB) interface, cellular network interface, Bluetooth™ interface, Near Field Communication (NFC) interface, etc. Communication interface 802 can facilitate communication across various network and protocol types, including wired networks (e.g., LAN, cable, etc.) and wireless networks (e.g., WLAN, cellular, satellite, etc.), the Internet, etc. Communication interface 802 can also provide communication with external storage devices (not shown), such as storage arrays, network-attached storage, storage area networks, etc.

[0251] In some examples, a display device 801, such as a monitor, may be included for displaying information and images to the user. Other I / O devices 803 may be devices that receive various inputs from the user and provide various outputs to the user, and may include touch input devices, gesture input devices, cameras, keyboards, remote controls, mice, printers, audio input / output devices, and so on.

[0252] The technologies described herein can be supported by various configurations of computing device 800, including but not limited to specific examples of the technologies described herein. For example, the functionality can also be implemented wholly or partially on a “cloud” using a distributed system. A cloud includes and / or represents a platform for resources. The platform abstracts the underlying functionality of the cloud’s hardware (e.g., servers) and software resources. Resources may include applications and / or data that can be used when performing computational processing on servers remote from computing device 800. Resources may also include services provided via the Internet and / or via subscriber networks such as cellular or Wi-Fi networks. The platform can abstract resources and functionality to connect computing device 800 to other computing devices. Therefore, the implementation of the functionality described herein can be distributed throughout the cloud. For example, the functionality can be implemented partly on computing device 800 and partly through a platform that abstracts the functionality of the cloud.

[0253] This application also provides a computer-readable storage medium storing instructions that, when executed individually or jointly by one or more processors of a computing device, cause the computing device to perform the methods described in any of the above embodiments.

[0254] Computer-readable storage media include volatile and non-volatile, removable and non-removable media implemented by any method or technology for storing information such as computer-readable instructions, data structures, program modules, or other data. Computer-readable storage media include, but are not limited to, RAM, ROM, EEPROM, flash memory or other memory technologies, CD-ROM, DVD, or other optical storage devices, magnetic cassettes, magnetic tapes, disk storage devices or other magnetic storage devices, or any other non-transmission medium that can be used to store information for access by computer equipment.

[0255] This application provides a computer program product including instructions that, when executed individually or jointly by one or more processors of a computing device, cause the computing device to perform the methods described in any of the above embodiments.

[0256] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application.

[0257] This embodiment provides a battery cell 11, including a positive electrode 110, a negative electrode 130, and a separator 120 located between the positive electrode 110 and the negative electrode 130. The positive electrode 110 includes a first body 111 and a first tab 112 disposed at a first end of the first body 111 along a first direction X. The first body 111 includes a first current collector 1116 and a first active layer 1117 disposed on the surface of the first current collector 1116. The first current collector 1116 has an empty foil region 1118 protruding from the first active layer 1117. The first tab 112 is disposed at the first end of the empty foil region 1118 along the first direction X. The empty foil region 1118 is provided with an insulating portion 140, and the insulating portion 140 also covers a portion of the first active layer 1117. The width of the empty foil region is 1.5 mm to 3.5 mm.

[0258] The insulating part 140 is an insulating adhesive paper. The first body 111 has a first surface 1112 and a second surface 1113 disposed opposite to each other along the second direction Y. The first surface 1112 and the second surface 1113 are both provided with insulating parts 140. The insulating part 140 disposed on the first surface 1112 has a first protrusion 1114 protruding from the first surface 1112. The insulating part 140 disposed on the second surface 1113 has a second protrusion 1115 protruding from the second surface 1113. The first protrusion 1114 and the second protrusion 1115 are bonded to each other.

[0259] The insulating tape is a white, semi-transparent tape with a light transmittance of 65%–80% and a haze of 60%–100%, ensuring it can be distinguished from the diaphragm in the field of view of the inspection camera. The insulating tape includes an adhesive layer 141 (adhesive layer) and an insulating layer 142 (substrate). The substrate composition includes at least one of PET, polypropylene, polyethylene, and polypropylene block copolymers, while the tape composition includes at least one of polyolefin, polyester, and styrene-isobutylene copolymers.

[0260] The insulating tape does not undergo redox reactions within a voltage range of 2.5V to 4.5V and remains stable in the electrolyte. After immersion in the electrolyte for 1000 hours, the peel strength is required to be 15–20 N / m. The insulating tape is insulating and will not break down at 200V, with a resistance greater than 9999 MΩ.

[0261] The thickness of the insulating tape is 9μm to 30μm, and the width is 4.5mm to 12mm. The width of the insulating tape in the first active layer region is 0.1mm to 2mm.

[0262] The battery cell structure provided in this embodiment can be applied to lithium-ion battery cells such as wound batteries, stacked batteries, and blade batteries. Because the insulating portion can block all separators except the current layer separator from the field of view of the detection camera, the separator area identified by the detection camera is the current layer separator. This allows for accurate measurement of the overhang between the separator and the negative electrode, improving the accuracy of the detection results. Furthermore, compared to infrared projection detection methods in related technologies, it does not require penetrating multiple layers, eliminating missed detections and false negatives, resulting in more accurate detection results.

[0263] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and not to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application, and they should all be covered within the scope of the claims and specification of this application. In particular, as long as there is no structural conflict, the various technical features mentioned in the embodiments can be combined in any way. This 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 battery cell, characterized in that, include: A positive electrode, a negative electrode, and a separator located between the positive electrode and the negative electrode; The positive electrode includes a first body and a first tab disposed at a first end of the first body along a first direction, and an insulating portion is disposed on the first body near the first tab, the insulating portion protruding from the first end of the first body and the first end of the diaphragm along the first direction; The optical properties of the insulating portion are different from those of the diaphragm, so that the first image of the insulating portion in the detection camera is different from the second image of the diaphragm in the detection camera.

2. The battery cell according to claim 1, characterized in that, The first body has a first surface and a second surface disposed opposite to each other along a second direction, and the insulating portion is disposed on the first surface or the second surface; wherein the first direction is perpendicular to the second direction.

3. The battery cell according to claim 1, characterized in that, The first body has a first surface and a second surface disposed opposite to each other along a second direction, and both the first surface and the second surface are provided with the insulating portion, wherein the first direction is perpendicular to the second direction.

4. The battery cell according to claim 3, characterized in that, The insulating portion disposed on the first surface has a first protrusion protruding from the first surface, and the insulating portion disposed on the second surface has a second protrusion protruding from the second surface, and the first protrusion and the second protrusion are connected.

5. The battery cell according to any one of claims 1-4, characterized in that, The first body includes a first current collector and a first active layer disposed on the surface of the first current collector. The first current collector has an empty foil area protruding from the first active layer. A first electrode is disposed at a first end of the empty foil area along the first direction. The insulating portion covers the empty foil area and also covers a portion of the first active layer.

6. The battery cell according to claim 5, characterized in that, The width H1 of the empty foil area along the first direction satisfies: 1.5mm≤H1≤3.5mm.

7. The battery cell according to claim 5 or 6, characterized in that, The width H2 of the portion of the insulating part covering the first active layer along the first direction satisfies: 0.1mm ≤ H2 ≤ 2mm.

8. The battery cell according to any one of claims 5-7, characterized in that, The width H3 of the insulating part along the first direction satisfies: 4.5mm≤H3≤12mm.

9. The battery cell according to any one of claims 1-8, characterized in that, The insulating part includes an adhesive layer and an insulating layer. One side of the adhesive layer is bonded to the insulating layer, and the other side of the adhesive layer is bonded to the first body.

10. The battery cell according to claim 9, characterized in that, The insulating layer is composed of at least one of polyethylene terephthalate, polypropylene, polyethylene, and polypropylene block copolymers.

11. The battery cell according to claim 9 or 10, characterized in that, The adhesive layer is composed of at least one of polyolefin, polyester, and styrene-isobutylene copolymer.

12. The battery cell according to any one of claims 1-11, characterized in that, The light transmittance A of the insulating part satisfies: 65% ≤ A ≤ 80%.

13. The battery cell according to any one of claims 1-12, characterized in that, The haze B of the insulation part satisfies: 60% ≤ B ≤ 100%.

14. The battery cell according to any one of claims 1-13, characterized in that, The thickness H4 of the insulating portion along the second direction perpendicular to the first direction satisfies: 9μm≤H4≤30μm.

15. The battery cell according to any one of claims 1-14, characterized in that, When the insulating part is immersed in the electrolyte for 1000 hours, the peel strength C of the insulating part satisfies: 15N / m≤C≤20N / m.

16. The battery cell according to any one of claims 1-15, characterized in that, The puncture strength D of the insulation part satisfies: D≥400gf.

17. The battery cell according to any one of claims 1-16, characterized in that, The insulating part has electrochemical stability when the voltage U satisfies 2.5V≤U≤4.5V.

18. A battery device, characterized in that, Includes the battery cell as described in any one of claims 1-17.

19. An electrical appliance, characterized in that, The electrical device includes the battery device as described in claim 18, the battery device being used to provide electrical energy.

20. An energy storage device, characterized in that, The energy storage device includes the battery device as described in claim 18, the battery device being used to store electrical energy.

21. A method for detecting overhang dimensions, characterized in that, The method includes: The detection camera acquires a detection image of the part to be detected, wherein the part to be detected includes a positive electrode sheet, a separator and a negative electrode sheet arranged in sequence, the positive electrode sheet, the negative electrode sheet and the separator are wound or stacked to form a battery cell according to any one of claims 1-17, the detection camera is located on the side of the negative electrode sheet away from the separator, and the detection image captures the insulating part of the negative electrode sheet, the separator and the positive electrode sheet; Determine the first region in the detection image where the diaphragm is located and the second region in the detection image where the negative electrode is located; Based on the first region and the second region, the overhang dimensions of the diaphragm and the negative electrode at the part to be tested are determined.

22. An overhang dimension detection device, characterized in that, The device includes: An acquisition module is used to acquire a detection image of a part to be detected by a detection camera, wherein the part to be detected includes a positive electrode sheet, a separator and a negative electrode sheet arranged in sequence, the positive electrode sheet, the negative electrode sheet and the separator are wound or stacked to form a battery cell according to any one of claims 1-17, the detection camera is located on the side of the negative electrode sheet away from the separator, and the detection image captures the insulating part of the negative electrode sheet, the separator and the positive electrode sheet; The first determining module is used to determine the first region where the diaphragm is located in the detection image and the second region where the negative electrode is located in the detection image; The second determining module is used to determine the overhang dimensions of the diaphragm and the negative electrode at the location to be tested, based on the first region and the second region.

23. A computing device, characterized in that, include: At least one processor; as well as At least one memory communicatively connected to the at least one processor, the at least one memory storing instructions that, when executed individually or jointly by the at least one processor, cause the computing device to perform the method of claim 21.

24. A computer-readable storage medium, characterized in that, The device stores instructions that, when executed individually or jointly by one or more processors of the computing device, cause the computing device to perform the method of claim 21.

25. A computer program product, characterized in that, Includes instructions that, when executed individually or jointly by one or more processors of the computing device, cause the computing device to perform the method of claim 21.

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