Battery cell, battery and electric device

Abstract

Provided in the embodiments of the present application are a battery cell, a battery and an electric device. The battery cell comprises an electrode assembly and an adhesive tape, wherein the electrode assembly comprises a first electrode sheet; and the adhesive tape is attached to the first electrode sheet and comprises a substrate, an adhesive layer and contrast agent particles, the adhesive layer being located on one side of the substrate in the direction of thickness, and the contrast agent particles being embedded in the adhesive layer. The technical solution provided in the present application can improve the yield rate of battery cells.

Description

Battery cell, battery and electric device Cross-reference to related applications

[0001] This application claims priority to Chinese Patent Application No. 202420723979.4, filed on April 9, 2024, entitled “Battery cell, battery and electric device”, the entire contents of which are incorporated herein by reference. TECHNICAL FIELD

[0002] The present application relates to the technical field of batteries, in particular to a battery cell, a battery and an electric device. BACKGROUND

[0003] Energy saving and emission reduction is the key to the sustainable development of the automobile industry. Electric vehicles have become an important part of the sustainable development of the automobile industry due to their energy-saving and environmentally friendly advantages. For electric vehicles, battery technology is an important factor for their development.

[0004] In the development of battery technology, how to improve the yield of the battery is a technical problem that needs to be solved in battery technology. SUMMARY

[0005] The present application provides a battery cell, a battery and an electric device, which can improve the yield of the battery cell.

[0006] The present application is achieved by the following technical solutions:

[0007] In a first aspect, the present application provides a battery cell, which comprises an electrode assembly and a gum paper, the electrode assembly comprising a first electrode sheet, the gum paper being attached to the first electrode sheet, the gum paper comprising a base material, a glue layer and contrast agent particles, the glue layer being located on one side of the base material in the thickness direction, and the contrast agent particles being embedded in the glue layer.

[0008] In the technical solution of the present application, the gum paper comprises a base material and a glue layer, and the gum paper can be attached to the first electrode sheet of the electrode assembly through the glue layer on the base material. When the electrode assembly of the battery cell is wound and formed, visual inspection cannot detect whether the gum paper inside the electrode assembly is folded. By embedding contrast agent particles in the glue layer, when the electrode assembly is wound and formed, the contrast agent particles in the glue layer can be projected and imaged by a contrast device (such as an X-ray detection machine). The brightness difference of the imaging can be used to detect whether the gum paper inside the electrode assembly is folded, so that the electrode assembly with folded gum paper can be detected normally, reducing the risk of defective products flowing out, and thus improving the yield of the battery cell.

[0009] According to some embodiments of the present application, the base material is a porous material.

[0010] In the above scheme, the substrate is adopted as a porous material, which is more conducive to the active ions to pass through the pores of the adhesive paper during the charging and discharging process of the battery cell, so that the capacity of the area of the battery cell to which the adhesive paper is attached can be normally exerted.

[0011] According to some embodiments of the present application, the substrate has a first surface in the thickness direction, and the adhesive layer is arranged on the first surface, and the first surface includes a coated area coated with the adhesive layer and a blank area not coated with the adhesive layer.

[0012] In the above scheme, the first surface of the substrate includes a coated area and a blank area, and when the adhesive paper is applied to the electrode sheet of the battery cell, the blank area on the first surface is arranged, which is more conducive to the active ions to pass through the pores of the adhesive paper, and effectively reduces the risk of lithium precipitation during the charging and discharging process of the battery cell.

[0013] According to some embodiments of the present application, the porosity of the substrate is not less than 35% and not more than 65%.

[0014] In the above scheme, the porosity of the substrate is controlled within the range, which can ensure that the active ions normally pass through the adhesive paper, and does not affect the stability of the strength of the substrate itself. When the porosity of the substrate is less than 35%, the porosity is too small, the number of pores is small, and the passing efficiency of the active ions through the adhesive paper is easily affected. When the porosity of the substrate is greater than 65%, the porosity is too large to affect the strength of the substrate.

[0015] According to some embodiments of the present application, the electrode assembly is in a winding structure, and the electrode assembly further includes a second electrode sheet and a separator, the first electrode sheet and the second electrode sheet are opposite in polarity, and the separator is arranged between the first electrode sheet and the second electrode sheet; wherein the adhesive paper is attached to at least one bending segment of the first electrode sheet.

[0016] In the above scheme, the adhesive layer of the adhesive paper can be attached to at least one bending segment of the first electrode sheet, on the one hand, the adhesive paper can protect the bending segment of the first electrode sheet, reduce the risk of cracking and powdering of the area of the first electrode sheet to which the adhesive paper is attached, thereby reducing the risk of the separator being punctured and causing the positive and negative electrodes to be short-circuited during the cycle process of the battery cell. On the other hand, when the substrate of the adhesive paper is a porous material, and the first surface of the substrate has a blank area not coated with the adhesive layer, the active ions (such as lithium ions) can normally pass through the blank area not coated with the adhesive layer on the adhesive paper during the charging and discharging process of the battery cell. Compared with the full coating of the adhesive layer on the first surface of the substrate, the area of the active ions passing through the adhesive paper is increased, and the blocking effect of the adhesive paper on the movement of the active ions is reduced, so that the capacity of the area of the battery cell to which the adhesive paper is attached can be normally exerted. Since the active ions can normally pass through the adhesive paper, the active ions are less likely to accumulate at the edge of the adhesive paper, thereby reducing the risk of lithium precipitation of the battery cell.

[0017] According to some embodiments of the present application, the two sides of the thickness direction of the at least one bending section are attached with adhesive paper.

[0018] In the above scheme, the two sides of the thickness direction of the at least one bending section are attached with adhesive paper, so that the two sides of the bending section of the first pole piece are protected by the adhesive paper, the compression resistance of the two sides of the bending section of the pole piece is relatively more balanced, the pole piece is less likely to crack, the safety of the battery monomer is ensured, and the risk of metal ions being precipitated on the surface of the negative pole piece is reduced.

[0019] According to some embodiments of the present application, the bending section of the innermost circle of the first pole piece is attached with adhesive paper.

[0020] In the above scheme, when the battery monomer is shaped, the bending section of the innermost side of the first pole piece is folded the most, and the first pole piece is more likely to crack and shed powder, so the bending section of the innermost circle of the first pole piece is attached with adhesive paper to protect the bending section of the innermost circle of the first pole piece, thereby reducing the risk of cracking and shedding powder of the first pole piece.

[0021] According to some embodiments of the present application, the first pole piece is a positive pole piece.

[0022] According to some embodiments of the present application, the first pole piece includes a first tab, in the width direction of the first pole piece, the diaphragm has a first edge corresponding to the first tab, and the first tab exceeds the first edge; in the width direction of the first pole piece, the adhesive paper includes a first end portion corresponding to the first edge, and the first end portion does not exceed the first edge.

[0023] In the above scheme, the first end portion of the adhesive paper is set not to exceed the first edge, so as to avoid the phenomenon of false reporting of the tab in the manufacturing process, thereby affecting the manufacturing efficiency of the battery.

[0024] According to some embodiments of the present application, the diaphragm further includes a second edge opposite to the first edge, and the adhesive paper includes a second end portion corresponding to the second edge, and the second end portion exceeds the second edge.

[0025] In the above scheme, by making the second end portion of the adhesive paper exceed the second edge, it is convenient to detect whether the adhesive paper is missed or whether the adhesive paper is folded in the manufacturing process of the electrode assembly, which is more conducive to controlling the yield of the battery monomer.

[0026] In a second aspect, the present application provides a battery including the battery monomer in the above embodiments.

[0027] In a third aspect, the present application provides a use device including the battery monomer of the above embodiments or the battery of the above embodiments, and the battery monomer or the battery is used to provide electric energy.

[0028] Additional aspects and advantages of the present application will be made apparent from the following description. BRIEF DESCRIPTION OF DRAWINGS

[0029] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments. It should be understood that the following drawings only show some of the embodiments of the present application, and therefore should not be considered as a limitation to the scope. For those skilled in the art, other related drawings can also be obtained without creative labor.

[0030] Fig. 1 is a structural schematic diagram of a vehicle according to some embodiments of the present application;

[0031] Fig. 2 is an exploded structural schematic diagram of a battery according to some embodiments of the present application;

[0032] Fig. 3 is a sectional structural schematic diagram of an electrode assembly in a battery monomer according to some embodiments of the present application;

[0033] Fig. 4 is a sectional view of the adhesive paper pasted on the first tab according to some embodiments of the present application;

[0034] Fig. 5 is a structural schematic diagram of the adhesive paper after being folded on the first tab according to some embodiments of the present application;

[0035] Fig. 6 is a schematic diagram of the battery monomer in a detection state on a bottom support plate according to some embodiments of the present application;

[0036] Fig. 7 is a structural schematic diagram of the first tab in the battery monomer before being wound according to some embodiments of the present application;

[0037] Fig. 8 is a structural schematic diagram of the adhesive paper in the first tab in the battery monomer according to some embodiments of the present application.

[0038] In the drawings, the drawings are not drawn according to the actual scale.

[0039] Label explanation: 10 - box; 11 - first part; 12 - second part; 20 - battery monomer; 22 - electrode assembly; 221 - first tab; 2210 - first tab; 2211 - first bending section; 2212 - second bending section; 222 - second tab; 23 - adhesive paper; 230 - base material; 231 - adhesive layer; 232 - first end; 233 - second end; 2341 - adhesive area; 2342 - blank area; 235 - contrast agent particles; 24 - separator; 241 - first edge; 242 - second edge; 243 - folding part; 100 - battery; 200 - controller; 300 - motor; 400 - bottom support plate; 500 - detection machine; 1000 - vehicle. DETAILED DESCRIPTION

[0040] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some but not all of the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0041] Unless otherwise defined, all technical and scientific terms used in the present application have the same meaning as commonly understood by one of ordinary skill in the art to which the present application belongs; the terms used in the present application are only for the purpose of describing the specific embodiments and are not intended to limit the present application; the terms "include" and "have" and any variations thereof in the description of the present application and the claims and the above description of drawings are intended to cover the non-exclusive inclusion. The terms "first", "second" and the like in the description of the present application and the claims or the above description of drawings are used to distinguish different objects, not to describe a particular order or primary and secondary relationship.

[0042] In the present application, the phrase "embodiments" means that the specific features, structures or characteristics described in connection with the embodiments can be included in at least one embodiment of the present application. The phrase appears at various places in the specification does not necessarily all refer to the same embodiments, nor are they necessarily mutually exclusive or alternative embodiments to each other. It is explicitly and implicitly understood by those skilled in the art that the embodiments described in the present application can be combined with other embodiments.

[0043] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mount", "connect", "connection", "attach" should be understood broadly, for example, can be fixedly connected, can be detachably connected, or integrally connected; can be directly connected, or indirectly connected through an intermediate medium, can be the internal communication of two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0044] In the present application, the term "and / or" is only a description of the association relationship between the associated objects, which means that there can be three relationships, for example, A and / or B can mean that A exists alone, A and B exist together, and B exists alone. In addition, the character " / " in the present application generally represents an "or" relationship between the associated objects before and after it.

[0045] As used herein, the term "plurality" means two or more (including two), and the term "plurality of groups" means two or more groups (including two groups), and the term "plurality of pieces" means two or more pieces (including two pieces).

[0046] In some embodiments, the battery can be a battery module, and when there are a plurality of battery cells, the plurality of battery cells are arranged and fixed to form a battery module.

[0047] In some embodiments, the battery can be a battery pack, and the battery pack includes a box body and battery cells, and the battery cells or the battery module are accommodated in the box body.

[0048] In some embodiments, the box body can be part of the chassis structure of the vehicle. For example, part of the box body can be at least part of the floor of the vehicle, or part of the box body can be at least part of the cross beam and the longitudinal beam of the vehicle.

[0049] In some embodiments, the battery can be an energy storage device. The energy storage device includes an energy storage container, an energy storage cabinet, etc.

[0050] In the embodiments of the present application, the battery cell can be a secondary battery, which refers to a battery cell that can be activated by charging after discharging.

[0051] The battery cell can be, but is not limited to, a lithium ion battery, a sodium ion battery, a sodium lithium ion battery, a lithium metal battery, a sodium metal battery, a lithium sulfur battery, a magnesium ion battery, a nickel hydrogen battery, a nickel cadmium battery, a lead-acid battery, etc.

[0052] As an example, the battery cell can be a cylindrical battery cell, a prismatic battery cell, a soft-pack battery cell, or a battery cell of other shapes, and the prismatic battery cell includes a square battery cell.

[0053] The battery cell generally includes an electrode assembly. The electrode assembly includes a positive electrode, a negative electrode, and a separator. During the charging and discharging process of the battery cell, active ions (such as lithium ions) are embedded and extracted between the positive electrode and the negative electrode. The separator is arranged between the positive electrode and the negative electrode, and can prevent the positive electrode and the negative electrode from short-circuiting, while allowing the active ions to pass through.

[0054] In some embodiments, the positive electrode can be a positive electrode tab, and the positive electrode tab can include a positive electrode current collector and a positive electrode active material arranged on at least one surface of the positive electrode current collector.

[0055] As an example, the positive electrode current collector has two opposite surfaces in the thickness direction of itself, and the positive electrode active material is arranged on any one or both of the two opposite surfaces of the positive electrode current collector.

[0056] As an example, the positive electrode current collector can employ a metal foil or a composite current collector. For example, as a metal foil, aluminum subjected to silver plating on the surface, stainless steel subjected to silver plating on the surface, stainless steel, copper, aluminum, nickel, a carbon electrode, carbon, nickel, or titanium, or the like can be employed. The composite current collector can include a polymer material base layer and a metal layer. The composite current collector can be formed by forming a metal material (aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver, and silver alloy, or the like) on a polymer material base material (such as a base material of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, or the like).

[0057] As an example, the positive electrode active material can include at least one of lithium-containing phosphates, lithium transition metal oxides, and modified compounds of each thereof. However, the present application is not limited to these materials, and other conventional materials that can be used as a battery positive electrode active material can also be used.

[0058] In some embodiments, the negative electrode can be a negative electrode tab, and the negative electrode tab can include a negative electrode current collector.

[0059] As an example, the negative electrode current collector can employ a metal foil or a composite current collector. For example, as a metal foil, aluminum subjected to silver plating on the surface, stainless steel subjected to silver plating on the surface, stainless steel, copper, aluminum, nickel, a carbon electrode, carbon, nickel, or titanium, or the like can be employed.

[0060] In some embodiments, the negative electrode current collector has two surfaces opposite in the thickness direction thereof, and the negative electrode active material is disposed on either one or both of the two surfaces of the negative electrode current collector.

[0061] As an example, the negative electrode active material can employ a negative electrode active material for a battery known in the art. As an example, the negative electrode active material can include at least one of artificial graphite, natural graphite, soft carbon, hard carbon, a silicon-based material, a tin-based material, lithium titanate, and the like. The silicon-based material can be selected from at least one of elemental silicon, a silicon oxide compound, a silicon-carbon composite, a silicon-nitrogen composite, and a silicon alloy. The tin-based material can be selected from at least one of elemental tin, a tin oxide compound, and a tin alloy. However, the present application is not limited to these materials, and other conventional materials that can be used as a battery negative electrode active material can also be used. These negative electrode active materials can be used alone or in combination of two or more.

[0062] In some embodiments, the separator is a separator film. The present application does not have a particular limitation on the type of separator film, and any known porous structure separator film having good chemical stability and mechanical stability can be used.

[0063] As an example, the main material of the separator can be selected from at least one of glass fiber, non-woven fabric, polyethylene, polypropylene, and polyvinylidene fluoride. The separator can be a single layer film or a multi-layer composite film, and is not particularly limited. When the separator is a multi-layer composite film, the materials of the respective layers can be the same or different, and are not particularly limited. The separator can be a separate component located between the positive and negative electrodes, or can be attached to the surfaces of the positive and negative electrodes.

[0064] In some embodiments, the separator is a solid-state electrolyte. The solid-state electrolyte is disposed between the positive and negative electrodes, and functions to transport ions and separate the positive and negative electrodes.

[0065] In some embodiments, the electrode assembly is in a wound structure. The positive electrode sheet and the negative electrode sheet are wound to form the wound structure.

[0066] At present, from the development of market situation, the application of power battery is more and more widely. Power battery is not only applied to energy storage power supply system of hydraulic, thermal, wind and solar power station, but also widely used in electric bicycles, electric motorcycles, electric vehicles and other electric vehicles, military equipment, aerospace and other fields. With the continuous expansion of the application field of power battery, the demand of its market is also increasing.

[0067] The development of battery technology needs to consider many design factors, such as energy density, charge and discharge rate, and discharge capacity of the battery. In addition, the yield of the battery also needs to be considered.

[0068] At present, the naked electrode assembly of the winding type is prone to corner cracking and powder falling during the shaping process. In order to alleviate the problem of sheet cracking and powder falling, the existing technology usually adopts the method of pasting adhesive tape on the sheet of the electrode assembly, especially on the bending section of the sheet, to solve the problem of cracking and powder falling of the bending section of the sheet of the electrode assembly due to pressure. However, after pasting the adhesive tape on the electrode assembly, there is a risk of folding of the adhesive tape during the winding process of the electrode assembly. Since the electrode assembly is in a winding structure after winding, there is no detection means for the folded adhesive tape, which is easy to cause the flow of defective battery monomers, thereby reducing the yield of the battery monomers.

[0069] Based on the above consideration, in order to improve the reliability of the battery monomer, the present application designs a battery monomer, which comprises an electrode assembly and an adhesive tape. The electrode assembly comprises a first sheet, the adhesive tape comprises a substrate, a glue layer and contrast agent particles, the substrate is pasted on the first sheet through the glue layer, and the contrast agent particles are embedded in the glue layer.

[0070] In the battery cell, by adding the contrast agent particles in the adhesive layer, after the electrode assembly is completed, the electrode assembly is comprehensively detected by a contrast device (for example, an X-ray detector), the X-ray detector can image the adhesive paper with the contrast agent particles in the electrode assembly, and according to the brightness color difference after imaging, it is judged whether the adhesive paper is folded, so as to ensure that the electrode assembly after the adhesive paper is folded can be normally detected, the risk of defective product outflow is reduced, and the yield of the battery cell is improved.

[0071] The battery cell disclosed in the embodiments of the present application can be used in, but is not limited to, an electric device such as a vehicle, a ship or an aircraft. A power supply system of the electric device can be composed of the battery cell and the battery disclosed in the present application.

[0072] The embodiments of the present application provide an electric device using a battery as a power supply. The electric device can be, but is not limited to, a mobile phone, a tablet, a notebook computer, an electric toy, an electric tool, an electric vehicle, an electric car, a ship, a spacecraft and the like. The electric toy can include a fixed or mobile electric toy, such as a game console, an electric car toy, an electric ship toy and an electric aircraft toy, and the spacecraft can include an airplane, a rocket, a space shuttle and a spacecraft.

[0073] The following embodiments are described by taking a vehicle as an example for convenience of description.

[0074] Please refer to FIG. 1, which is a structural schematic diagram of a vehicle 1000 provided by some embodiments of the present application. The vehicle 1000 can be a fuel automobile, a gas automobile or a new energy automobile, and the new energy automobile can be a pure electric automobile, a hybrid electric automobile or a range extended automobile. The vehicle 1000 is internally provided with a battery 100, which can be arranged at the bottom, the head or the tail of the vehicle 1000. The battery 100 can be used for power supply of the vehicle 1000, for example, the battery 100 can be used as an operating power supply of the vehicle 1000. The vehicle 1000 can further include a controller 200 and a motor 300, and the controller 200 is used to control the battery 100 to supply power to the motor 300, for example, to meet the working power demand of the vehicle 1000 during starting, navigation and driving.

[0075] In some embodiments of the present application, the battery 100 can not only be used as an operating power supply of the vehicle 1000, but also be used as a driving power supply of the vehicle 1000, to replace or partially replace fuel or natural gas to provide driving power for the vehicle 1000.

[0076] Please refer to FIG. 2, which is an exploded view of the battery 100 according to some embodiments of the present application. The battery 100 includes a box 10 and a battery cell 20, which is accommodated in the box 10. The box 10 is configured to provide a space for accommodating the battery cell 20, and can have various structures. In some embodiments, the box 10 can include a first part 11 and a second part 12, which are coupled to each other to define a space for accommodating the battery cell 20. The second part 12 can be a hollow structure with one open end, and the first part 11 can be a plate structure, which is coupled to the open end of the second part 12 to define the space for accommodating the battery cell 20 together with the second part 12. Alternatively, the first part 11 and the second part 12 can both be hollow structures with one open end, and the open end of the first part 11 is coupled to the open end of the second part 12. Of course, the box 10 formed by the first part 11 and the second part 12 can have various shapes, such as a cylinder or a cuboid.

[0077] In the battery 100, the battery cell 20 can be multiple, and the multiple battery cells 20 can be connected in series, in parallel, or in a mixed manner. The mixed manner means that the multiple battery cells 20 are connected in series and in parallel. The multiple battery cells 20 can be directly connected in series, in parallel, or in a mixed manner, and then the multiple battery cells 20 are accommodated in the box 10. Of course, the battery 100 can also be that the multiple battery cells 20 are connected in series, in parallel, or in a mixed manner to form a battery module, and then the multiple battery modules are connected in series, in parallel, or in a mixed manner to form a whole, which is accommodated in the box 10. The battery 100 can further include other structures, for example, the battery 100 can further include a busbar component for electrically connecting the multiple battery cells 20.

[0078] Each battery cell 20 can be a secondary battery or a primary battery, and can also be a lithium-sulfur battery, a sodium-ion battery, or a magnesium-ion battery.

[0079] The battery cell 20 refers to the smallest unit of the battery. The battery cell 20 includes an end cover, a shell, an electrode assembly, and other functional components.

[0080] The end cover is a component that covers the opening of the shell to isolate the internal environment of the battery monomer 20 from the external environment. Without limitation, the shape of the end cover can be adapted to the shape of the shell to fit the shell. Optionally, the end cover can be made of a material with certain hardness and strength, such as an aluminum alloy, so that the end cover is less likely to deform when subjected to a pressing impact, allowing the battery monomer to have higher structural strength and improved reliability. The end cover can be provided with functional components such as electrode terminals. The electrode terminals can be used to electrically connect with the electrode assembly for outputting or inputting the electrical energy of the battery monomer 20. The material of the end cover can also be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and the present application does not make special limitations on this. In some embodiments, an insulating structure can also be provided on the inner side of the end cover, which can be used to isolate the electrical connection components in the shell from the end cover to reduce the risk of short circuit. Exemplarily, the insulating structure can be plastic, rubber, etc.

[0081] The electrode assembly is a component in which electrochemical reactions occur in the battery monomer 20. The shell can contain one or more electrode assemblies. The electrode assembly is mainly formed by winding or stacking the positive and negative electrode sheets, and a separator is usually provided between the positive and negative electrode sheets to separate the positive and negative electrode sheets to avoid internal short circuit of the positive and negative electrode sheets. The positive and negative electrode sheets have a portion of active material constituting the main body of the electrode assembly, and the portions of the positive and negative electrode sheets without active material each constitute a tab. The positive and negative tabs can be located together at one end of the main body or at two ends of the main body, respectively.

[0082] The present application provides a battery monomer. Please refer to FIG. 3 and FIG. 4, FIG. 3 is a cross-sectional structure schematic diagram of an electrode assembly in a battery monomer according to some embodiments of the present application, and FIG. 4 is a cross-sectional view of a gum paper attached to a first electrode sheet according to some embodiments of the present application. The battery monomer 20 includes an electrode assembly 22 and a gum paper 23, the electrode assembly 22 includes a first electrode sheet 221, and the gum paper 23 is attached to the first electrode sheet 221. The gum paper 23 includes a base material 230, a gum layer 231, and contrast agent particles 235. The gum layer 231 is located on one side of the thickness direction Z of the base material 230, and the contrast agent particles 235 are embedded in the gum layer 231.

[0083] The adhesive paper 23 is attached to the first pole piece 221 through the adhesive layer 231. The adhesive paper 23 can be attached to one side of the first pole piece 221 in the thickness direction Z, or can be attached to both sides of the first pole piece 221 in the thickness direction Z. The material of the adhesive layer 231 can be maleic anhydride modified polypropylene or acrylic acid, etc. The contrast agent particles 235 are embedded in the adhesive layer 231. Understandably, when the adhesive paper 23 is prepared, the contrast agent particles 235 are embedded in the adhesive layer 231, and then coated on the surface of the substrate 230, or after the adhesive layer 231 is coated on the surface of the substrate 230, the contrast agent particles 235 are embedded in the adhesive layer 231. The contrast agent is in the form of particles, and the contrast agent can include barium sulfate and iodine preparations, which are high-density contrast agents with good contrast. Of course, the type of iodine preparation can be metrizamide or sodium diatrizoate, etc.

[0084] Please refer to FIG. 5, which is a structure diagram of the adhesive paper of the first pole piece after folding according to some embodiments of the present application. One end of the substrate 230 is folded to form a folded part 243, which overlaps on the substrate 230. When the electrode assembly 22 is subjected to imaging, the brightness of the folded part 243 is different from that of the rest of the substrate 230, so that whether the adhesive paper 23 of the electrode assembly 22 is folded can be determined by judging whether there is a brightness difference on the substrate 230.

[0085] In the technical solution of the embodiments of the present application, the adhesive paper 23 includes a substrate 230 and an adhesive layer 231, and the adhesive paper 23 can be attached to the first pole piece 221 of the electrode assembly 22 through the adhesive layer 231 on the substrate 230. When the electrode assembly 22 is wound and formed, visual inspection cannot detect whether the adhesive paper 23 in the electrode assembly 22 is folded. By embedding contrast agent particles 235 in the adhesive layer 231, after the electrode assembly 22 is wound and formed, please refer to FIG. 6, which is a schematic diagram of a battery cell in a detection state on a bottom support plate according to some embodiments of the present application. The electrode assembly 22 is placed on the bottom support plate 400, and the electrode assembly 22 is irradiated by a contrast imaging device (for example, an X-ray detection machine 500). The contrast agent particles 235 in the adhesive layer 231 can be imaged with the contrast imaging device, and whether the adhesive paper 23 in the electrode assembly 22 is folded can be detected according to the brightness difference of the imaging. The electrode assembly 22 with the folded adhesive paper 23 can be normally detected, which reduces the risk of defective products flowing out, and thus improves the yield of the battery cell.

[0086] According to some embodiments of the present application, the substrate 230 is a porous material.

[0087] The porous material here refers to a material with many small pores, which can filter larger particles but allow metal ions to pass through.

[0088] Substrate 230 can be made of polypropylene, polyethylene, or non-woven fabric. Polypropylene (PP) is a polymer formed by the addition polymerization of propylene. It is a thermoplastic synthetic resin with excellent performance and is a colorless, translucent, lightweight, general-purpose thermoplastic plastic. Polyethylene (PE) is a thermoplastic resin produced by the polymerization of ethylene monomers. Non-woven fabric, also known as non-woven fabric, needle-punched cotton, or needle-punched non-woven fabric, is made of polyester fiber (PET) and is produced through a needle-punching process.

[0089] The substrate 230 is made of a porous material, which facilitates active ions to penetrate the pores of the adhesive tape 23 during the charge and discharge process of the battery cell, thereby ensuring that the capacity of the area where the adhesive tape 23 is attached in the battery cell can be fully utilized.

[0090] According to some embodiments of the present application, please refer to Figure 8, which is a schematic diagram of the structure of the adhesive tape in the first electrode sheet of a battery cell in some embodiments of the present application. A substrate 230 has a first surface in a thickness direction Z, with an adhesive layer 231 disposed on the first surface. The first surface includes an adhesive-coated area 2341 coated with the adhesive layer 231 and a blank area 2342 not coated with the adhesive layer 231.

[0091] The first surface of the substrate 230 is the entire surface along the thickness direction Z of the substrate 230. The glue-coated area 2341 refers to all areas on the substrate 230 coated with the glue layer 231, and the blank area 2342 is the area on the first surface of the substrate 230 that is not coated with the glue layer 231.

[0092] The blank area 2342 on the first surface of the substrate 230 can have various forms. For example, the adhesive layer 231 can include multiple sub-adhesive layers 231, which are spaced apart in stripes on the first surface of the base layer. The area between two adjacent sub-adhesive layers 231 forms the blank area 2342. Of course, the adhesive layer 231 can also be applied to the first surface of the substrate 230 in a dotted pattern, a "田" (field) pattern, a "井" (well-shaped) pattern, or any other shape.

[0093] Please refer to Figure 8, which is a schematic diagram of the structure of the adhesive tape in the first electrode sheet of a battery cell in some embodiments of the present application. The first surface of the substrate 230 includes an adhesive-coated area 2341 and a blank area 2342. During the charge and discharge process of the battery cell, since the adhesive layer 231 blocks the active ions of the battery cell, the provision of the blank area 2342 on the first surface facilitates the penetration of active ions through the pores of the adhesive tape 23, effectively reducing the risk of lithium plating.

[0094] According to some embodiments of the present application, the porosity of the substrate 230 is not less than 35% and not more than 65%.

[0095] The porosity of the substrate 230 can be any value between 35% and 65%, for example, the porosity of the substrate 230 can be 35%, 40%, 45%, 50%, 55%, 60%, 65%, etc.

[0096] Controlling the porosity of the substrate 230 within this range can ensure that active ions can normally pass through the adhesive paper 23, and at the same time, the stability of the strength of the substrate 230 is not affected. When the porosity of the substrate 230 is less than 35%, the porosity is too small, the number of pores is small, and the passing efficiency of active ions through the adhesive paper 23 is easily affected. When the porosity of the substrate 230 is greater than 65%, the porosity is too large to affect the strength of the substrate 230.

[0097] According to some embodiments of the present application, referring to FIG. 3, the electrode assembly 22 is in a wound structure, and the electrode assembly 22 further includes a second tab 222 and a separator 24, the first tab 221 and the second tab 222 are opposite in polarity, and the separator 24 is arranged between the first tab 221 and the second tab 222; wherein the adhesive paper 23 is attached to at least one bending section of the first tab 221.

[0098] The electrode assembly 22 is in a wound structure, the wound structure is wound by fixing a winding needle, the first tab 221 and the second tab 222 are one of a positive electrode tab and a negative electrode tab, and the separator 24 is arranged between the first tab 221 and the second tab 222, which can prevent the first tab 221 and the second tab 222 from short-circuiting, and at the same time, active ions can pass through. The main body of the electrode assembly 22 includes a straight section and a bending section, and the bending section is connected to one end of the straight section. The first tab 221 of the straight section extends along a straight trajectory, and the tab of the bending section extends along a bending trajectory.

[0099] The adhesive paper 23 can be attached to at least one bending section of the first tab 221, on the one hand, the adhesive paper 23 can protect the bending section of the first tab 221, reducing the risk of cracking and powdering in the area of the first tab 221 where the adhesive paper 23 is attached, thereby reducing the risk of the separator 24 being punctured during the cycle of the battery monomer, causing the positive and negative electrodes to be in contact and short-circuiting.

[0100] In another aspect, when the base material 230 of the adhesive paper 23 is a porous material, and the first surface of the base material 230 has a blank area not coated with the adhesive layer 231, the active ions (e.g., lithium ions) can normally pass through the blank area of the adhesive paper 23 not provided with the adhesive layer 231 during the charging and discharging process of the battery cell. Compared with the case where the adhesive layer 231 is fully applied to the first surface of the base material 230, the area for the active ions to pass through the adhesive paper 23 is increased, and the blocking effect of the adhesive paper 23 on the movement of the active ions is reduced, so that the capacity of the area of the battery cell to which the adhesive paper 23 is attached can be normally exerted. Since the active ions can normally pass through the adhesive paper 23, the active ions are less likely to accumulate at the edge of the adhesive paper 23, thereby reducing the risk of metal ions being deposited on the surface of the negative electrode plate.

[0101] The adhesive paper 23 can be attached to one side of the corresponding bending segment of the first electrode plate 221, or can be attached to both sides of the corresponding bending segment of the first electrode plate 221 in the thickness direction. When the adhesive paper 23 is attached to one side of the first electrode plate 221, it is preferable to be attached to the inner side of the first electrode plate 221, which can further reduce the risk of lithium deposition. However, the outer side of the first electrode plate 221 is prone to uneven pressure, which can cause the outer side of the first electrode plate 221 to crack more easily.

[0102] According to some embodiments of the present application, the adhesive paper 23 is attached to both sides of the bending segment of the first electrode plate 221 in the thickness direction.

[0103] By attaching the adhesive paper 23 to both sides of the bending segment of the first electrode plate 221 in the thickness direction, the bending segment of the first electrode plate 221 is protected by the adhesive paper 23 on both sides, and the pressure resistance of the bending segment of the first electrode plate 221 is relatively more balanced, which can prevent the electrode plate from cracking and ensure the safety of the battery cell. In addition, the risk of metal ions being deposited on the surface of the negative electrode plate is reduced.

[0104] According to some embodiments of the present application, the adhesive paper 23 is attached to the bending segment of the innermost circle of the first electrode plate 221.

[0105] When the electrode assembly 22 is wound, please refer to FIG. 3, the bending segment of the innermost circle of the first electrode plate 221 in the electrode assembly 22 is subjected to the maximum stress and has the maximum folding amount, and the bending segment of the innermost circle is the most prone to cracking and powder falling.

[0106] In the present embodiment, the adhesive paper 23 is provided on the first bending segment 2211 and the second bending segment 2212 of the innermost circle of the first electrode plate 221. That is, the first bending segment 2211 and the second bending segment 2212 are the two bending segments formed by the first winding of the first electrode plate 221 when it is wound.

[0107] When the battery monomer is shaped, the first pole piece 221 is most likely to crack and shed powder due to the maximum folding amount of the innermost folding section of the first pole piece 221. Therefore, the adhesive tape 23 is attached to the innermost folding section of the first pole piece 221 to protect the innermost folding section of the first pole piece 221, thereby reducing the risk of cracking and shedding of the first pole piece 221.

[0108] According to some embodiments of the present application, the first pole piece 221 is a positive pole piece.

[0109] According to some embodiments of the present application, please refer to FIG. 7, which is a structural schematic diagram of the first pole piece in the battery monomer before winding according to some embodiments of the present application. The first pole piece 221 includes a first tab 2210. In the width direction X of the first pole piece 221, the separator 24 has a first edge 241 corresponding to the first tab 2210, and the first tab 2210 exceeds the first edge 241. In the width direction X of the first pole piece 221, the adhesive tape 23 includes a first end 232 corresponding to the first edge 241, and the first end 232 does not exceed the first edge 241.

[0110] The first edge 241 refers to the edge of the separator 24 close to the first tab 2210 in the width direction X of the first pole piece 221. The first end 232 refers to the end of the adhesive tape 23 close to the first tab 2210 in the width direction X of the first pole piece 221. The width direction X of the first pole piece 221, the length direction Y of the first pole piece 221 and the thickness direction Z of the first pole piece 221 are perpendicular to each other.

[0111] The first end 232 of the adhesive tape 23 is set not to exceed the first edge 241 to avoid the inductor mistaking the first end 232 of the base material 230 for the first tab 2210 in the manufacturing process, thereby avoiding the false tab phenomenon and affecting the manufacturing efficiency of the battery.

[0112] According to some embodiments of the present application, please refer to FIG. 7, the separator 24 further includes a second edge 242 opposite to the first edge 241, and the adhesive tape 23 includes a second end 233 corresponding to the second edge 242, and the second end 233 exceeds the second edge 242.

[0113] The second edge 242 refers to the other edge of the separator 24 opposite to the first edge 241 in the width direction X of the first pole piece 221. The second end 233 refers to the other end of the adhesive tape 23 opposite to the first end in the width direction X of the first pole piece 221.

[0114] By making the second end portion 233 of the adhesive paper 23 beyond the second edge 242, it is convenient to detect whether the adhesive paper 23 is missed or folded during the manufacturing process of the electrode assembly 22, which is more conducive to controlling the yield of the battery monomer and improving the reliability of the battery monomer.

[0115] In a second aspect, the application provides a battery comprising the battery monomer 20 in the above embodiments.

[0116] In a third aspect, the application provides a power consuming device comprising the battery monomer or the battery in the above embodiments, and the battery monomer 20 or the battery is used to provide electric energy.

[0117] According to some embodiments of the application, referring to FIG. 3, FIG. 4, FIG. 5 and FIG. 6, FIG. 3 is a cross-sectional structure schematic diagram of an electrode assembly in a battery monomer according to some embodiments of the application; FIG. 4 is a cross-sectional view of an adhesive paper attached to a first pole piece according to some embodiments of the application; FIG. 5 is a structure schematic diagram of the adhesive paper folded on the first pole piece according to some embodiments of the application; and FIG. 6 is a schematic diagram of a battery monomer in a detection state on a bottom support plate according to some embodiments of the application. The battery monomer 20 comprises an electrode assembly 22 and an adhesive paper 23. The electrode assembly 22 is in a winding structure, and comprises a first pole piece 221, a second pole piece 222 and a separator 24. The first pole piece 221 and the second pole piece 222 are opposite in polarity, and the separator 24 is arranged between the first pole piece 221 and the second pole piece 222. The adhesive paper 23 is attached to a folded section of an innermost circle of the first pole piece 221. The adhesive paper 23 comprises a base material 230, a glue layer 231 and contrast agent particles 235. The glue layer 231 is located on one side of the base material 230 in the thickness direction, and the contrast agent particles 235 are embedded in the glue layer 231. The base material 230 is of a porous material, and has a first surface in the thickness direction. The glue layer 231 is arranged on the first surface. The first surface comprises a glue-coated area 2341 coated with the glue layer 231 and a blank area 2342 not coated with the glue layer 231.

[0118] The contrast agent particles are added in the glue layer 231. After the winding of the electrode assembly 22 is completed, the electrode assembly 22 is comprehensively detected by a contrast equipment (for example, an X-ray detection machine 500). The X-ray detection machine 500 can image the adhesive paper 23 with the contrast agent particles 235 in the electrode assembly 22, and determine whether the adhesive paper 23 is folded according to the brightness color difference after imaging, so as to ensure that the electrode assembly 22 after the folding of the adhesive paper 23 can be normally detected, reduce the risk of defective products, and improve the yield of the battery monomer 20.

[0119] In one aspect, the adhesive layer 231 of the adhesive paper 23 can be attached to the innermost circle of the first pole piece 221, and the adhesive paper 23 can protect the innermost circle of the first pole piece 221, thereby reducing the risk of cracking and powdering of the first pole piece 221, and reducing the risk of positive and negative electrode contact short circuit caused by the puncture of the diaphragm 24 during the cycle of the battery cell.

[0120] In another aspect, when the base material 230 of the adhesive paper 23 is a porous material, and the first surface of the base material 230 has a blank area without the adhesive layer 231, during the charging and discharging process of the battery cell 20, active ions (such as lithium ions) can normally pass through the blank area of the adhesive paper 23 without the adhesive layer 231. Compared with the full coating of the adhesive layer 231 on the first surface of the base material 230, the area of the active ions passing through the adhesive paper 23 is increased, and the blocking effect of the adhesive paper 23 on the movement of the active ions is reduced, so that the capacity of the area of the battery cell with the adhesive paper 23 can be normally played. Since the active ions can normally pass through the adhesive paper 23, the active ions are not easy to accumulate at the edge of the adhesive paper 23, thereby reducing the risk of metal ions precipitating on the surface of the negative pole piece.

[0121] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement to part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application, and they should be covered in the scope of the claims and the description of the present application. Especially, as long as there is no structural conflict, each technical feature mentioned in each embodiment can be combined in any way. The present application is not limited to the specific embodiments disclosed in the text, but includes all technical solutions falling within the scope of the claims.

Claims

1. A battery cell, comprising: An electrode assembly, comprising a first electrode piece; The adhesive tape is attached to the first pole piece, and the adhesive tape includes a base material, an adhesive layer and contrast agent particles. The adhesive layer is located on one side of the base material in the thickness direction, and the contrast agent particles are embedded in the adhesive layer.

2. The battery cell according to claim 1, wherein: The substrate is made of porous material.

3. The battery cell according to claim 2, wherein: The substrate has a first surface in a thickness direction, the adhesive layer is arranged on the first surface, and the first surface includes an adhesive coating area coated with the adhesive layer and a blank area not coated with the adhesive layer.

4. The battery cell according to claim 2, wherein: The porosity of the substrate is not less than 35% and not more than 65%.

5. The battery cell according to any one of claims 1 to 4, wherein: The electrode assembly is a wound structure, and further includes a second electrode sheet and a diaphragm, wherein the first electrode sheet and the second electrode sheet have opposite polarities, and the diaphragm is disposed between the first electrode sheet and the second electrode sheet; Wherein, the adhesive tape is affixed to at least one bent section of the first pole piece. The battery cell according to claim 5 , wherein: The adhesive tape is attached to both sides of at least one bent section of the first pole piece in the thickness direction.

7. The battery cell according to claim 5, wherein: The adhesive tape is attached to the innermost bending section of the first pole piece.

8. The battery cell according to any one of claims 1 to 7, wherein: The first electrode is a positive electrode.

9. The battery cell according to claim 5, wherein: The first pole piece includes a first pole ear. In the width direction of the first pole piece, the diaphragm has a first edge corresponding to the first pole ear, and the first pole ear extends beyond the first edge; the adhesive tape includes a first end portion corresponding to the first edge, and the first end portion does not extend beyond the first edge.

10. The battery cell according to claim 9, wherein: The diaphragm further includes a second edge disposed opposite to the first edge, and the adhesive tape includes a second end portion disposed corresponding to the second edge, and the second end portion extends beyond the second edge.

11. A battery comprising the battery cell according to any one of claims 1 to 10.

12. An electrical device comprising the battery cell according to any one of claims 1 to 10 or the battery according to claim 11, wherein the battery cell or the battery is used to provide electrical energy.

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